Connectivity of chemosensory neurons is controlled by the gene poxn in Drosophila. The function of the nervous system depends on the formation of a net of appropriate connections, but little is known of the genetic program underlying this process. In Drosophila two genes that specify different types of sense organs have been identified: cut (ct), which specifies the formation of external sense organs as opposed to chordotonal organs, and pox-neuro (poxn), which specifies the formation of poly-innervated (chemosensory) organs as opposed to mono-innervated (mechanosensory) organs. Whether these genes are also involved in specifying the connectivity of the corresponding neurons is not known. The larval sense organs are unsuitable for analysis of the axonal pathway and connections and so we have investigated the effect of poxn on the adult. Here we show that overexpression of poxn induces the morphological transformation of mechanosensory into chemosensory bristles on the legs and that the neurons innervating the morphologically transformed bristles follow pathways and establish connections that are appropriate for chemosensory bristles.


Enterotoxin residues determining T-cell receptor V beta binding specificity. Superantigens such as the staphylococcal enterotoxins bind to major histocompatibility complex (MHC) class II molecules and activate T cells through a specific interaction between the V beta region of the T-cell antigen receptor (TCR) and the toxin. The TCR beta-chain alone is sufficient to produce the interaction with the enterotoxin-class II complex. Identification of the regions of enterotoxins that interact with TCR has so far proved equivocal because of difficulties in distinguishing between direct effects on T-cell recognition and indirect effects resulting from alteration of binding to class II. For example, amino-terminal truncations of SEB abrogated T-cell stimulation whereas carboxy-terminal truncation of SEA stopped its mitogenic activity. The most comprehensive study to date, accounting for both enterotoxin binding to class II and enterotoxin interactions with the TCR, identified two functionally important regions for SEB binding to TCR. Although the amino-acid sequences of staphylococcal enterotoxins A and E are 82% identical, they activate T cells bearing different V beta elements. We have assayed the binding of cells coated with these enterotoxins to soluble secreted TCR beta-chain protein and find that V beta 3 binds enterotoxin A but not E, whereas V beta 11 binds enterotoxin but not A. To map the amino-acid residues responsible for these different binding specificities, we prepared a series of hybrids between the two staphylococcal enterotoxins. We report that just two amino-acid residues near the carboxy terminus of the enterotoxins are responsible for the discrimination between these molecules by V beta 3 and V beta 11.(ABSTRACT TRUNCATED AT 250 WORDS)


Structure of hisactophilin is similar to interleukin-1 beta and fibroblast growth factor. The fast reaction of the actin-based cytoskeleton in motile cells after stimulation with a chemoattractant requires a signal-transduction chain that creates a very specific environment at distinct regions beneath the plasma membrane. Dictyostelium hisactophilin, a unique actin-binding protein, is a submembranous pH sensor that signals slight changes of the H+ concentration to actin by inducing actin polymerization and binding to microfilaments only at pH values below seven. It has a relative molecular mass of 13.5K and its most unusual feature is the presence of 31 histidine residues among its total of 118 amino acids. The transduction of an external signal from the plasma membrane to the cytoskeleton is poorly understood. Here we report the protein's structure in solution determined by nuclear magnetic resonance spectroscopy. The nuclear Overhauser effect intensities of the three-dimensional nuclear Overhauser spectra were used directly in the calculations. The overall folding of histactophilin is similar to that of interleukin-1 beta and fibroblast growth factor, but the primary amino-acid sequence of hisactophilin is unrelated to these two proteins.


Stable dye-DNA intercalation complexes as reagents for high-sensitivity fluorescence detection. Fluorescent intercalation complexes of certain polycationic ligands with double-stranded DNA provide a new class of multichromophore labels for fluorescence assays.


The infectiousness of pompous prose.

The infectiousness of pompous prose. For centuries, scientists have been bombarded with pleas for plain language. Why have these pleas had no effect, when the problem of unreadable prose could be solved at a stroke?


Stabilization of sea urchin flagellar microtubules by histone H1. Complex microtubule assemblies are essential components of eukaryotic cilia and flagella. They are extremely stable and are not affected by agents that normally induce polymer disassembly. The molecular basis of this microtubular stability is unknown, and it is not related to any feature of the constitutive tubulin. In sea urchin sperm flagella, axonemal microtubules are found to be stabilized by a protein identical to histone H1, a result that defines a new role for this histone and provides evidence for a concerted evolution of chromatin and microtubular structures.


Crystal structure of TFIID TATA-box binding protein. The structure of a central component of the eukaryotic transcriptional apparatus, a TATA-box binding protein (TBP or TFIID tau) from Arabidopsis thaliana, has been determined by X-ray crystallography at 2.6 A resolution. This highly symmetric alpha/beta structure contains a new DNA-binding fold, resembling a molecular 'saddle' that sits astride the DNA. The DNA-binding surface is a curved, antiparallel beta-sheet. When bound to DNA, the convex surface of the saddle would be presented for interaction with other transcription initiation factors and regulatory proteins.


Absence of aluminium in neuritic plaque cores in Alzheimer's disease. Controversy exists over whether aluminium has a role in the aetiology of Alzheimer's disease. Alzheimer's disease is neuropathologically characterized by the occurrence of a minimum density of neurofibrillary tangles and neuritic plaques in the hippocampus and the association cortex of the brain. The purported association of aluminium with Alzheimer's disease is based on: (1) the experimental induction of fibrillary changes in the neurons of animals by the injection of aluminium salts into brain tissue; (2) reported detection of aluminium in neuritic plaques and tangle-bearing neurons; (3) epidemiological studies linking aluminium levels in the environment, notably water supplies, with an increased prevalence of dementia; and (4) a reported decrease in the rate of disease progression following the administration of desferroxamine, an aluminium chelator, to clinically diagnosed sufferers of Alzheimer's disease. Here we use nuclear microscopy, a new analytical technique involving million-volt nuclear particles, to identify and analyse plaques in postmortem tissue from patients with Alzheimer's disease without using chemical staining techniques and fail to demonstrate the presence of aluminium in plaque cores in untreated tissue.


Real and optimal neural images in early vision. It has been suggested that the first steps in visual processing strive to compress as much information as possible about the outside world into the limited dynamic range of the visual channels. Here I compare measured neural images with theoretical calculations based on maximizing information, taking into account the statistical structure of natural images. Neural images were obtained by scanning an image while recording from a second-order neuron in the fly visual system. Over a 5.5-log-units-wide range of mean intensities, experiment and theory correspond well. At high mean intensities, redundancy in the image is reduced by spatial and temporal antagonism. At low mean intensities, spatial and temporal low-pass filtering combat noise and increase signal reliability.


Preserved figure-ground segregation and symmetry perception in visual neglect. A central controversy in current research on visual attention is whether figures are segregated from their background preattentively, or whether attention is first directed to unstructured regions of the image. Here we present neurological evidence for the former view from studies of a brain-injured patient with visual neglect. His attentional impairment arises after normal segmentation of the image into figures and background has taken place. Our results indicate that information which is neglected and unavailable to higher levels of visual processing can nevertheless be processed by earlier stages in the visual system concerned with segmentation.


A new tropomyosin essential for cytokinesis in the fission yeast S. pombe. Mutations in the Schizosaccharomyces pombe cdc8 gene impair cytokinesis. Here we clone cdc8+ and find that it encodes a novel tropomyosin. Gene disruption results in lethal arrest of the cell cycle, but spore germination, cell growth, DNA replication and mitosis are all unaffected. Haploid cdc8 gene disruptants are rescued by expression of a fibroblast tropomyosin complementary DNA. Immunofluorescence microscopy of wild type and cdc8 gene disruptants indicates that cdc8 tropomyosin is present in two distinct cellular distributions: in dispersed patches, and during cytokinesis as a transient medial band. Collectively these results indicate that cdc8 tropomyosin has a specialized role which, we suggest, is to form part of the F-actin contractile ring at cytokinesis. These results establish the basis for further genetic studies of cytokinesis and of contractile protein function in S. pombe.


Zebrafish pax[b] is involved in the formation of the midbrain-hindbrain boundary. Among the genes thought to be involved in patterning the nervous system are a family of developmentally regulated paired box-containing (Pax) genes. Mutations in some of these Pax genes lead to severe developmental abnormalities. Zebrafish pax[b](pax[zf-b]) is a member of the Pax gene family that is expressed in the presumptive posterior midbrain from the end of gastrulation and, at later stages, in other localized regions of the developing embryo. Here we show that injection of antibodies raised against the pax[b] protein causes a localized malformation at the midbrain-hindbrain boundary. In situ hybridizations demonstrate that antibody injection causes downregulation of pax[b] transcripts in the posterior midbrain and alteration of wnt-1 and eng-2 expression in this area. The data demonstrate an involvement of pax[b] in the formation of the midbrain-hindbrain junction.


Message in a bottle.

Message in a bottle. Insights from the classic work of Luria and Delbrück on bacterial mutation rates may be applied to tracking human gene defects prevalent in isolated populations.


Structure of a C-type mannose-binding protein complexed with an oligosaccharide. C-type (Ca(2+)-dependent) animal lectins such as mannose-binding proteins mediate many cell-surface carbohydrate-recognition events. The crystal structure at 1.7 A resolution of the carbohydrate-recognition domain of rat mannose-binding protein complexed with an oligomannose asparaginyl-oligosaccharide reveals that Ca2+ forms coordination bonds with the carbohydrate ligand. Carbohydrate specificity is determined by a network of coordination and hydrogen bonds that stabilizes the ternary complex of protein, Ca2+ and sugar. Two branches of the oligosaccharide crosslink neighbouring carbohydrate-recognition domains in the crystal, enabling multivalent binding to a single oligosaccharide chain to be visualized directly.


Motor learning in a recurrent network model based on the vestibulo-ocular reflex. Most models of neural networks have assumed that neurons process information on a timescale of milliseconds and that the long-term modification of synaptic strengths underlies learning and memory. But neurons also have cellular mechanisms that operate on a timescale of tens or hundreds of milliseconds, such as a gradual rise in firing rate in response to injection of constant current or a rapid rise followed by a slower adaptation. These dynamic properties of neuronal responses are mediated by ion channels that are subject to modulation. We demonstrate here how a neural network with recurrent feedback connections can convert long-term modulation of neural responses that occur over these intermediate timescales into changes in the amplitude of the steady output from the system. This general principle may be relevant to many feedback systems in the brain. Here it is applied to the vestibulo-ocular reflex, whose amplitude is subject to long-term adaptive modification by visual inputs. The model reconciles apparently contradictory data on the neural locus of the cellular mechanisms that mediate this simple form of learning and memory.


A single amino-acid difference confers major pharmacological variation between human and rodent 5-HT1B receptors. Neuropsychiatric disorders such as anxiety, depression, migraine, vasospasm and epilepsy may involve different subtypes of the 5-hydroxytryptamine (5-HT) receptor. The 1B subtype, which has a unique pharmacology, was first identified in rodent brain. But a similar receptor could not be detected in human brain, suggesting the absence in man of a receptor with equivalent function. Recently a human receptor gene was isolated (designated 5-HT1B receptor, 5-HT1D beta receptor, or S12 receptor) which shares 93% identity of the deduced protein sequence with rodent 5-HT1B receptors. Although this receptor is identical to rodent 5-HT1B receptors in binding to 5-HT, it differs profoundly in binding to many drugs. Here we show that replacement of a single amino acid in the human receptor (threonine at residue 355) with a corresponding asparagine found in rodent 5-HT1B receptors renders the pharmacology of the receptors essentially identical. This demonstrates that the human gene does indeed encode a 1B receptor, which is likely to have the same biological functions as the rodent 5-HT1B receptor. In addition, these findings show that minute sequence differences between homologues of the same receptor from different species can cause large pharmacological variation. Thus, drug-receptor interactions should not be extrapolated from animal to human species without verification.


Cell-free expression of functional Shaker potassium channels. The functional activity of ion channels and other membrane proteins requires that the proteins be correctly assembled in a transmembrane configuration. Thus, the functional expression of ion channels, neurotransmitter receptors and complex membrane-limited signalling mechanisms from complementary DNA has required the injection of messenger RNA or transfection of DNA into Xenopus oocytes or other target cells that are capable of processing newly translated protein into the surface membrane. These approaches, combined with voltage-clamp analysis of ion channel currents, have been especially powerful in the identification of structure-function relationships in ion channels. But oocytes express endogenous ion channels, neurotransmitter receptors and receptor-channel subunits, complicating the interpretation of results in mRNA-injected eggs. Furthermore, it is difficult to control experimentally the membrane lipids and post-translational modifications that underlie the regulation and modulation of ion channels in intact cells. A cell-free system for ion channel expression is ideal for good experimental control of protein expression and modulatory processes. Here we combine cell-free protein translation, microsomal membrane processing of nascent channel proteins, and reconstitution of newly synthesized ion channels into planar lipid bilayers to synthesize, glycosylate, process into membranes, and record in vitro the activity of functional Shaker potassium channels.


Proteasome subunits encoded in the MHC are not generally required for the processing of peptides bound by MHC class I molecules. Antigen processing provides major histocompatibility complex (MHC) class I molecules with short peptides, which they selectively bind and present to cytotoxic T lymphocytes. The proteolytic system generating these peptides in the cytosol is unidentified, but their delivery into the endoplasmic reticulum is mediated by the TAP1-TAP2 transporter encoded in the MHC class II region. Closely linked to TAP1 and TAP2 are genes for the LMP2 and LMP7 proteins, which resemble components of proteasomes, proteolytic complexes known to degrade cytosolic proteins. This association has led to the common assumption that proteasomes function in this immunological pathway (discussed in ref. 15). We now show that the expression of stably assembled class I molecules and apparently normal peptide processing can be completely restored in the absence of LMP2 and LMP7 in the human lymphoblastoid cell line mutant 721.174 (refs 16, 17). The identity of LMP7 is directly confirmed by reconstitution of a proteasomal subunit after gene transfer. These results therefore dispute the hypothetical involvement of proteasomes in antigen processing, although a more subtle effect of LMP2 and LMP7 cannot be ruled out.


Abrogation by c-myc of G1 phase arrest induced by RB protein but not by p53. Inactivating mutations of the retinoblastoma gene (RB) are found in a wide variety of tumour cells. Replacement of wild-type RB can suppress the tumorigenicity of some of these cells, suggesting that the RB protein (Rb) may negatively regulate cell growth. As activation of c-myc expression promotes cell proliferation and blocks differentiation, it may positively regulate cell growth. The c-myc protein is localized in the nucleus and can physically associate with RB protein in vitro, hence c-myc may functionally antagonize RB function. Microinjection of Rb in G1 phase reversibly arrests cell-cycle progression. Here we co-inject RB protein with c-myc, EJ-ras, c-fos or c-jun protein. Co-injection of c-myc, but not EJ-ras, c-fos or c-jun, inhibits the ability of Rb to arrest the cell cycle. The c-myc does not inhibit the activity of another tumour supressor, p53 (ref. 12). Thus, c-myc and RB specifically antagonize one another in the cell.


Actin cables and epidermal movement in embryonic wound healing. Skin wounds in embryos heal rapidly and perfectly. Even though the epidermis appears to be stretched taut over the surface of a structure such as a growing limb bud, its response to wounding is to close over the lesion, rather than to gape more widely. In adult wounds, the epidermis seems to migrate by means of lamellipodia, crawling over the exposed connective tissue. But in embryonic wounds we do not see lamellipodia. The epidermis at the edge of the wound looks smooth, as though under a circumferential tension. Here we show that a cable of filamentous actin appears to run continuously around most of the wound margin. It is confined to the single row of basal cells at the free edge of the epidermis. We suggest that the actin cable acts as a contractile 'purse string' to close up the embryonic wound.


Molecular and genetic damage in humans from environmental pollution in Poland. Extreme environmental pollution such as that found in the highly industrialized Silesian region of Poland has been associated with increased risk of cancer and adverse reproductive outcomes. Among the most prevalent carcinogenic and mutagenic air pollutants in Silesia are the polycyclic aromatic hydrocarbons (PAH) which are largely produced by industrial and residential combustion of coal. Molecular epidemiology aims to prevent disease by using biological markers to identify risks well before clinical onset to allow effective intervention. Here, we use a battery of biological markers to measure molecular and genetic damage in peripheral blood samples from residents of Silesia and from persons living in a rural, less polluted area of Poland. The results show that their exposure to environmental pollution is associated with significant increases in carcinogen-DNA adducts (PAH-DNA and aromatic adducts), in sister chromatid exchange including high-frequency cells, and in chromosomal aberrations as well as a doubling in the frequency of ras oncogene overexpression. We found that aromatic adducts on DNA were significantly correlated with chromosomal mutation, providing us with a molecular link between environmental exposure and a genetic alteration relevant to cancer and reproductive risk.


Enhancing protein C interaction with thrombin results in a clot-activated anticoagulant. Human protein C is a vitamin K-dependent plasma glycoprotein that circulates as an inactive zymogen. At the endothelial cell surface, thrombin in complex with the integral membrane protein thrombomodulin converts protein C to its active form by specific cleavage of an activation peptide. The activated form of protein C has potent anticoagulant activity as a feedback regulator of thrombin generation (reviewed in refs 4-6), and also has profibrinolytic, anti-ischaemic and anti-inflammatory properties. Protein C is effective in the treatment of model and human thrombotic diseases but, except when it has been used to treat genetic or acquired deficiencies and microvascular thrombosis, it is administered as the activated enzyme, which has a short biological half-life. We have altered two putative inhibitory acidic residues near the thrombin cleavage site, which results in a 30-fold increase in substrate utilization by alpha-thrombin. We combined these changes with a genetically altered glycoform to generate a zymogen protein C with a 60-fold increased cleavage rate by free alpha-thrombin, independent of its cofactor thrombomodulin. We show that this 'proform' of protein C, unlike the natural circulating zymogen, can be activated by thrombin generated in clotting human plasma, resulting in an inhibition of further clot formation. Our data therefore show that we have engineered a site-activated agent, which only has anticoagulant activity when significant amounts of thrombin are being generated.


Lifespan of human lymphocyte subsets defined by CD45 isoforms. The lifespan of thymic-derived or T lymphocytes is of particular interest because of their central role in immunological memory. Is the recall of a vaccination or early infection, which may be demonstrated clinically up to 50 years after antigen exposure, retained by a long-lived cell, or by its progeny? Using the observation that T lymphocyte expression of isoforms of CD45 corresponds with their ability to respond to recall antigens, we have investigated the lifespan of both CD45R0 (the subset containing responders, or 'memory' cells) and CD45RA (the unresponsive, or 'naive' subset) lymphocytes in a group of patients after radiotherapy. Here we report rapid loss of unstable chromosomes from the CD45R0 but not the CD45RA pool. Immunological memory therefore apparently resides in a population with a more rapid rate of division. Differing survival curves for the two subsets are best described by a model in which there is also reversion in vivo from the CD45R0 to the CD45RA phenotype. Expression of CD45R0 in T cells may therefore be reversible.


Rat liver protein linking chemical and immunological detoxification systems. Mammals have separate enzymatic and cellularly mediated detoxification systems. Glutathione S-transferases (GSTs) protect against xenobiotic chemicals which continuously enter the body, largely through mucous membranes. These enzymes catalyse the conjugation of glutathione with a wide variety of electrophilic compounds rendering them non-toxic. Mammals also mount a cellular immunological response on entry of foreign cells, viruses or macromolecules into the body. T lymphocytes mobilize at the site of foreign body entry and secrete protein messengers called lymphokines. Secondary to T lymphocytes, macrophages concentrate at the infection site and function in antigen processing and phagocytosis. In vitro, macrophage movement is arrested by one class of lymphokines known as macrophage migration inhibitory factors (MIFs). We report here the purification of milligram quantities of a unique multifunctional protein from rat liver which links enzymatic and immunological detoxification systems. This protein actuates both GST and MIF activity and matches the primary structure of a human MIF in 25 out of 26 amino-terminal amino acids. Primary structure comparisons revealed significant similarity between GSTs and MIF. The glutathione affinity chromatography purification described here yields a 100-fold increase in obtaining MIF and will aid understanding of its precise biological function.


NMR study of parallel-stranded tetraplex formation by the hexadeoxynucleotide d(TG4T). Multistranded DNA structures based upon guanine association have been proposed to be important in the structure of chromosome telomeres and in immunoglobulin class switching. Nucleic acids containing runs of guanine bases form a number of structures in vitro, including fold-back structures (Fig. 1a) and parallel-stranded quadruplex structures in DNA and RNA. The features of fold-back structures have now been determined at high-resolution. The different structures are probably based on a tetrad of hydrogen-bonded guanine bases (Fig. 1b), with buffer conditions and sequence effects mediating isomerization between the different forms. Here we use NMR spectroscopy to investigate the solution structure of the complex formed by the hexadeoxynucleotide d(TG4T) in the presence of sodium ions. We have observed the formation of a parallel-stranded quadruplex containing hydrogen-bonded tetrads of guanine. The parallel-stranded form differs significantly from the fold-back form, with individual nucleotide conformations being closer to those of B-form DNA.


[Modeling in biology. Structured analysis of intracellular calcium oscillations in electrically non-excitable cells]. In this paper a systematic approach to the mathematical modeling of intracellular Ca2+ oscillations is introduced. After a structured analysis a stochastic model of the system is derived which is numerically tractable by means of a stochastic simulation. A critical discussion of theoretical models for Ca2+ oscillations reveals that not all of the proposed mechanisms are consistent with experimental data. In addition, a model for oscillatory calcium waves is presented. Uncovering these mechanisms facilitates the design of anti-mitotic drugs interfering with Ca2+ metabolism.


[The phenomenon of hearing: an interdisciplinary discourse. I]. For the last century hearing has been considered a purely passive process. G. S. Ohm's and H. v. Helmholtz's resonance theory of hearing was widely accepted until Wien's fundamental objection led to G. v. Békésy's and O. F. Ranke's travelling wave theory, the hydrodynamics of the inner ear that distributes the frequencies along the basilar membrane, which acts as the "first filter". Seebeck, Licklider, Schouten, and deBoer emphasized also the time domain and developed the concept of periodicity hearing and the "residue phenomenon". However, it was not until the concept of the "cochlear amplifier" and "active hearing" with energy generation during the transduction process within the ear itself was introduced that the "second filter" could be understood. Kemp's echo was the key to this revolutionary step in the theory of hearing.


Differential coupling of 5-HT1A receptors occupied by 5-HT or 8-OH-DPAT to adenylyl cyclase. Human serotonin (5-hydroxytryptamine, 5-HT)-1A receptors have been transfected in NIH-3T3 cells, and their coupling to adenylyl cyclase was analysed depending on 1) the number of receptor expressed, 2) the experimental conditions used, 3) the nature of the agonists. Two monoclonal cell lines were used, expressing low (45 fmol/mg) and high (500 fmol/mg) levels of 5-HT1A receptor. Two methods were tested to study the negative coupling of the transfected 5-HT1A receptors to adenylyl cyclase: 1) measurement of cAMP production in intact cells, 2) measurement of adenylyl cyclase activity in vitro on membrane preparations. Studies on intact cells revealed that an increase in the receptor concentration was followed by 1) an increase in the efficacies of 5-HT, 5-CT (5-carboxamidotryptamine) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), 2) a 2 to 3-fold increase in the potency of 5-CT and 8-OH-DPAT, but no change in the potency of 5-HT. In membrane preparations, 8-OH-DPAT dose-response curve was shifted leftwards when the receptor concentration became higher whereas the corresponding shift was smaller for 5-HT and absent for 5-CT. Surprisingly, on membrane preparations, 8-OH-DPAT was a partial agonist relative to 5-HT. The relative efficacy of 8-OH-DPAT was lower in the clone expressing the lowest level of receptor. This partial agonist behavior of 8-OH-DPAT could be modulated by the ionic conditions under which the adenylyl cyclase activity was measured.(ABSTRACT TRUNCATED AT 250 WORDS)


Inhibitory and excitatory muscarinic receptors modulating the release of acetylcholine from the postganglionic parasympathetic neuron of the chicken heart. The effects of muscarinic receptor antagonists on ACh release were studied in the absence or presence of cholinesterase (ChE) inhibition using the isolated perfused chicken heart. Presynaptic inhibitory muscarinic autoreceptor were characterized by determining the potency of various antagonists to enhance [3H]-ACh release evoked by field stimulation (3 Hz, 1 min). The order of potencies was: (+/-)-telenzepine > atropine > 4-DAMP > silahexocyclium > pirenzepine > hexahydro-siladifenid-ol > AF-DX 116. The comparison with known pA2 values for M1-, M2- and M3-receptors revealed that the presynaptic autoreceptor meets the criteria of an M1-receptor. Basal, not electrically evoked overflow of unlabelled ACh into the perfusate was caused by 'leakage' release (non-exocytotic), as it was independent of extracellular Ca2+. Muscarinic receptor antagonists failed to enhance basel overflow. In contrast, when ChE activity was inhibited by 10(-6) M tacrine or pretreatment with 10(-4) M DFP, the ACh overflow was partially Ca(2+)-dependent and was reduced by tetrodotoxine. Moreover, block of the inhibitory muscarinic autoreceptors by (+/-)-telenzepine or pirenzepine caused a several-fold enhancement of the ACh release. The potencies of these antagonists were identical to those found for the electrically evoked [3H]-ACh release. The rate of ACh release enhanced by ChE inhibition plus telenzepine corresponds to about 12% of the total ACh pool per min, which is about the maximum amount of ACh that is available for any kind of stimuli. The release was dependent on the presence of exogenous choline. Hence elevation of ACh release led to a correspondingly enhanced ACh synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)


Quest for agonist and antagonist selectivity at muscarinic receptors in guinea-pig smooth muscles and cardiac atria. Potencies of 11 muscarinic agonists in eliciting contraction of smooth muscle in guinea-pig ileum, trachea, urinary bladder and uterus and in inhibiting the rate of contractions of cardiac atria were compared. While acetylcholine (ACh) was the most potent agonist on the ileum, uterus and cardiac atria, cis-L(+)-dioxolane was equally as potent as ACh on the ileum and more potent on the urinary bladder and trachea. Compared to ACh, methylfurmethide, oxotremorine, acetoxybut-2-inyl-trimethylammonium and cis-L(+)-dioxolane acted weakly on the atria. Aceclidine, arecoline and acetyl-beta-methylcholine displayed selectivity for the urinary bladder and pilocarpine for the tracheal and urinary bladder smooth muscles. Oxotremorine had very low activity on the uterus. The stereoselectivity of muscarinic ACh receptors (mAChRs) for cis-L(+)-and cis-D(-)-dioxolane was low in the urinary bladder and uterus and high in the ileum and trachea. Most antagonists showed little selectivity between different organs, but S(-)-phenylcyclohexylglycoloyl choline was 6 times more active on the urinary bladder than on the ileum and AF-DX 116 was 12-30 times more active on the atria than on the smooth muscles. Among the N-alkyl derivatives of benzilylcholine, the octyl derivative as 400 times more active on the ileum than on the atria, while among the N-alkyl derivatives of QNB, the N-decyl derivative was 41 times more active on the ileum. The observed differences in the potency of various agonists and their stereoisomers on different smooth muscles cannot be explained by differences in the accessibility of receptors or in receptor reserve.(ABSTRACT TRUNCATED AT 250 WORDS)


Evidence for M1 muscarinic cholinoceptors mediating facilitation of noradrenaline release in guinea-pig carotid artery. The muscarinic agonists acetylcholine (1-50 mumol/l), carbachol (1-10 mumol/l) and McN-A-343 (1-50 mumol/l, selective for M1 receptors) increased, in a concentration-dependent manner, the electrically-evoked tritium overflow from guinea-pig carotid arteries preincubated with [3H]-noradrenaline. The increase caused by acetylcholine was not modified by hexamethonium (300 mumol/l) but was reduced by the muscarinic receptor antagonists methylatropinium (0.5 and 1 nmol/l, non-selective), pirenzepine (1 and 5 nmol/l, M1-selective), methoctramine (1 and 5 mumol/l, M2-selective) and p-fluoro-hexahydro-sila-difenidol (0.1-1 mumol/l, M3-selective). The order of potencies (expressed as negative logarithms of concentrations that reduced by 50% the facilitatory effect of acetylcholine) was: methyl-atropinium (9.93) > pirenzepine (8.83) > p-fluoro-hexahydro-siladifenidol (6.81) > or = methoctramine (6.20). These results demonstrate the existence of facilitatory M1 receptors modulating noradrenaline release in blood vessels.


Nicotinic and muscarinic components of rat brain dopamine synthesis stimulation induced by physostigmine. The role of a putative cholinergic control of ascending midbrain dopamine neurons was studied with biochemical methods in the unanaesthetized male albino rat. Post-mortem catechols were measured with high performance liquid chromatography with electrochemical detection. The acetylcholinesterase inhibitor physostigmine (0.5 mg/kg s.c.) enhanced L-dihydroxyphenylalanine (DOPA) and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in both the corpus striatum and limbic areas (nucleus accumbens) after inhibition of aromatic amino acid decarboxylase with NSD-1015, indicating an enhanced synthesis of dopamine in these brain regions. The effect of physostigmine was blocked both in the corpus striatum and in limbic areas by the centrally penetrating muscarinic antagonist scopolamine (1.0 mg/kg s.c.). In contrast, the nicotinic antagonist mecamylamine (1.0 mg/kg s.c.) significantly reduced the stimulatory effect of physostigmine in limbic areas, but not in the corpus striatum. The present results suggest that ascending dopamine neurons are influenced by cholinergic synaptic transmission being mediated mainly by muscarinic receptors as regards the nigrostriatal system, and by both nicotinic and muscarinic receptors as regards the mesolimbic system. The nicotinic influence appears to primarily control phasic activity of the dopamine neurons.


Effect of ageing on the number of neuronal noradrenaline uptake sites in the rat vas deferens. Previous work has shown an age-related reduction in neuronal uptake of noradrenaline in the prostatic, but not in the epididymal portion of the rat vas deferens. In the present paper, the influence of ageing on the number of [3H]desipramine binding sites and on the effect of lithium on neuronal [3H]noradrenaline uptake were studied in the prostatic and epididymal portions of vasa deferentia from 4- and 20-month-old rats. The affinity for [3H]desipramine (Kd values) in the epididymal and prostatic portions did not change with age. However, ageing reduced the maximal number of [3H]desipramine binding sites (Bmax values) in the prostatic, but not in the epididymal portion. Lithium potentiated neuronal [3H]noradrenaline uptake only in the prostatic portion and this potentiation was not changed by ageing. The results showed differences in neuronal noradrenaline uptake between the two portions of the vas deferens. Furthermore, the data suggest that the age-related reduction in neuronal uptake in the prostatic portion is due to a reduction in the number of neuronal uptake sites for noradrenaline.


Changes in cholecystokinin receptor binding in rat brain after selective damage of locus coeruleus projections by DSP-4 treatment. Brain cholecystokinin (CCK)- and noradrenergic activities are two neurochemical systems implicated in anxiety and deficits in novelty-related behaviour. In order to clarify a possible interaction between CCK- and noradrenergic neurotransmission in the brain, DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine], a neurotoxin that selectively destroys noradrenaline-containing nerve terminals originating from the locus coeruleus, was administered to rats IP (10 and 50 mg/kg) seven days before decapitation. Noradrenaline uptake was very markedly reduced in the frontal cortex and hippocampus of the DSP-4 treated animals, whereas the decrease in the hypothalamus was smaller but still statistically significant. Dopamine uptake in the corpus striatum, as well as serotonin uptake in the frontal cortex, hippocampus and hypothalamus, were not influenced by DSP-4 treatment. Concomitantly, CCK receptor binding in certain brain regions was markedly affected. Thus, CCK receptor density was significantly higher in the frontal cortex and hippocampus of DSP-4-treated rats. If desipramine (25 mg/kg) was administered before DSP-4 treatment, the DSP-4-induced changes both in noradrenaline uptake and CCK receptor binding were not present, suggesting that both effects were exerted after uptake of the neurotoxin by the nerve terminals. The time-course of the development of changes in CCK-8 binding paralleled with some lag the development of changes in noradrenaline uptake. These findings demonstrate the denervation of noradrenergic input from the locus coeruleus induces certain alterations in the CCKergic neurotransmission. These alterations are similar to those seen in rats with deficits in response to novel stimuli, and may therefore mediate the neophobic responses observed in animals after lesions of noradrenergic innervation of the forebrain.


Alcohol withdrawal reaction as a result of adaptive changes of excitatory amino acid receptors. Recent electrophysiological and biochemical studies suggest that ethanol interferes with excitatory amino acid (EAA) neurotransmission. Here, we present electrophysiological evidence that, following cessation of a chronic ethanol treatment, noradrenergic locus coeruleus (LC) neurons display hyperactivity at the same time as a specifically enhanced sensitivity to microiontophoretically applied NMDA or quisqualate. Furthermore, after chronic ethanol treatment, but not before, the NMDA receptor antagonist MK 801 (0.3-2.4 mg/kg, i.v.) dose-dependently inhibited the firing of the LC neurons. Our data indicate that an up-regulation of EAA receptors located on LC neurons accounts for the changes in LC firing in ethanol-treated rats. We propose that activation of the LC contributes to the clinical signs of the ethanol abstinence reaction and that EAA antagonists may be beneficial therapeutically for its treatment.


Studies on the effect of two angiotensin-converting enzyme inhibitors, captopril and cilazapril, on platelet and vascular prostaglandin metabolism in vivo. We have studied in 12 healthy volunteers the effects of two angiotensin-converting enzyme (ACE) inhibitors, captopril and cilazapril, on vascular and platelet prostaglandin metabolism, in a double-blind, placebo-controlled, randomized cross-over study. Formation of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2) was measured locally at the site of a microvascular injury. Similar amounts of TxB2 and 6-keto-PGF1 alpha were generated following administration of either ACE inhibitor as compared to placebo. It is concluded that neither captopril nor cilazapril significantly influence vascular and platelet prostaglandin metabolism.


Evaluation of the effects of felodipine, verapamil and hydralazine on the survival rate of rats subjected to lethal effects of oxygen free radicals. Intravenous administration of xanthine (X: 0.225 mg/kg, i.v.) plus xanthine oxidase (XO: 3.0 units/kg, i.v.) to anesthetized rats resulted in a rapid fall in the arterial pressure and a mortality rate of over 80% during 120 min observation period. Pretreatment of the rats with superoxide dismutase (SOD) or SOD plus catalase significantly enhanced survival rate to 60% confirming that the toxicity after [X + XO] administration is due to the generation of oxygen free radicals. Pretreatment of the rats with either felodipine, a dihydropyridine calcium antagonist or verapamil, a structurally different Ca(2+)-channel blocker was most effective in promoting survival rate to 90%; in contrast, hydralazine, an arteriolar dilator but not a calcium antagonist, was ineffective in significantly enhancing survival. In the vehicle treated groups, mortality of the rats after [X + XO] administration was associated with significant increases in serum creatine phosphokinase (CPK) levels; both the calcium antagonists as well as hydralazine prevented any significant changes in CPK levels. Since only the calcium antagonists but not hydralazine were effective in providing significant protection against mortality, the data suggests that CPK may not be a reliable indicator to predict prevention of lethal toxicity induced by free radicals. Hence, the observation that calcium antagonists can promote survival would suggest that calcium overload may be the ultimate mediator of tissue toxicity. These observations can account for the remarkable efficacy of various calcium antagonists in preventing ischemia-reperfusion induced damage to organs, such as heart and kidneys, in which a role for free radicals has been postulated.


The relaxant effects of cromakalim (BRL 34915) on human isolated airway smooth muscle. Cromakalim (BRL 34915) is a potassium channel opener with therapeutic potential as a bronchodilator in asthma. Cromakalim (0.1-30 mumol/l) inhibited the spontaneous tone of human isolated bronchi in a concentration-related manner being nearly as effective as isoprenaline or theophylline. The order of relaxant potencies (expressed as -log10 IC50 mol/l; mean +/- SEM) was isoprenaline (7.29 +/- 0.27; n = 8) > cromakalim (5.89 +/- 0.12; n = 7) > theophylline (4.07 +/- 0.13; n = 10). In human bronchi where tone had been raised by addition of histamine (0.1 mmol/l), acetylcholine (0.1 mmol/l) or leukotriene D4 (LTD4, 0.1 mumol/l), the relaxant effect of cromakalim was substantially reduced. Cromakalim suppressed the contraction produced by KCl (25 mmol/l) but not that produced by KCl (120 mmol/l). Tetraethylammonium (8 mmol/l) was without effect against the relaxant action of cromakalim but procaine (0.5-5 mmol/l) and glibenclamide (0.3 mumol/l) antagonised it. Cromakalim (10 mumol/l) produced an upward displacement of concentration-effect curves for KCl (1-100 mmol/l), acetylcholine (1 nmol/l-1 mmol/l) and histamine (1 nmol/l-1 mmol/l) but it did not alter the concentration-effect curve for LTD4 (0.1 nmol/l-0.1 mumol/l). When tissues were challenged in the presence of cromakalim (10 mumol/l) with KCl (100 mmol/l), acetylcholine (1 mmol/l) or histamine (1 mmol/l), an enhanced contraction was observed compared to control tissues. This enhancement by cromakalim was absent when tissues were challenged with acetylcholine or histamine in either a Ca(2+)-free medium (plus EGTA 0.1 mmol/l) or in the presence of verapamil (10 mumol/l).(ABSTRACT TRUNCATED AT 250 WORDS)


Feeding but not salt loading is the dominant factor controlling urinary dopamine excretion in conscious rats. We studied urinary dopamine excretion in three different groups of rats after the following treatment regimens: normal chow and tap water (controls, CON), normal chow and 1% NaCl as drinking water (high salt, HS), and chow with low sodium content plus tap water (low salt, LS). On days 5 and 7 of the respective dietary treatment, rats were placed in metabolic cages. Using a cross over design, chow was given (fed) or withheld (fasted). Urine was collected for 24 h and analyzed for sodium, creatinine, and dopamine. Urinary dopamine excretion did not change in proportion to large differences in sodium excretion in fasted animals. Sodium excretion was enhanced (45%) due to feeding only in the CON group but not in HS and LS rats. However, there was a striking increase in renal dopamine excretion in fed compared to fasted animals, irrespective of their sodium diet: 2.5-fold in CON, 2-fold in HS, and 1.8-fold in LS rats. Urinary creatinine excretion was significantly elevated during the feeding condition compared to fasted animals in all treatment groups. Our results demonstrate that urinary dopamine excretion is dominantly influenced by feeding but not by oral sodium intake in conscious rats. We conclude that 1) the dietary state of the animals should be controlled in experiments on renal dopamine production, 2) renally formed dopamine could be involved in the functional response of the kidney to oral food intake.


Depression by neuropeptide Y of noradrenergic inhibitory postsynaptic potentials of locus coeruleus neurones. Intracellular recordings were performed in a pontine slice preparation of the rat brain containing the locus coeruleus (LC). The spontaneous firing of action potentials was prevented by passing continuous hyperpolarizing current via the recording electrode. Focal electrical stimulation evoked a synaptic depolarization (PSP) followed by a hyperpolarization (IPSP). Neuropeptide Y (NPY; 0.1 mumol/l) inhibited the IPSP only. Pressure ejection of noradrenaline produced hyperpolarization which was potentiated in the presence of NPY (0.1 mumol/l). Hence, NPY appears to inhibit the release of noradrenaline from dendrites or recurrent axon collaterals of LC neurones.


Prudent prescribing. Prescribing suggestions for physicians. "A significant problem facing patients throughout the country is the rising cost of medical care. In addition to the physician's fees and laboratory charges of a routine office visit, patients may face an even greater bill from the pharmacy. There are several ways that physicians can help."


[Value and risks of percutaneous cytological puncture in the preoperative assessment of pancreas tumors]. In a period of a little over two years 34 preoperative fine needle aspiration biopsies were performed in 32 patients with a possible malignant lesion of the pancreas. A cytological diagnosis of cancer was obtained in 22 patients. On follow-up 27 patients, in whom 28 biopsies were performed, proved to have a malignant tumour. The overall sensitivity of fine needle aspiration cytology in diagnosing a malignancy was 77.8%. There were no false positive results (specificity: 100%). Three patients developed serious biopsy-related complications. This relatively low sensitivity and the fact that a biopsy is not without risk leads to the advice not to perform preoperative fine needle aspiration biopsies as a routine in patients in whom curative or palliative surgery is indicated. Percutaneous biopsy is advised and can be useful if no indication for surgery is present because of the patient's condition or the extent of the disease and non-surgical palliation is the treatment of choice.


[Percutaneous bile duct drainage; experiences with a new type of endoprosthesis]. Self expandable stents were placed percutaneously in 105 patients with malignant biliary obstruction. Stent diameter was 1 cm; length, 3.5-10.5 cm. Of the 60 patients with common bile duct obstruction, 50 died 0.2-12 months (median 3 months) after stent insertion. Two patients developed recurrent jaundice and cholangitis after 6 and 12 months, respectively. One patient underwent reintervention. Ten patients, one after a successful reintervention, were alive without jaundice 1-8 months (median 5 months) after stent placement. Of the 45 patients with hilar lesions, 26 died 0.7-18 months (median 5 months) after stent placement, five of them with signs of cholangitis. Nineteen are alive 1-21 months (median 7 months) afterwards. Reinterventions were carried out in 13 patients (29%). The most common cause of stent malfunction was tumour overgrowth. Stent-related complications were seen in three patients.


[Unnecessarily taxing treatment of congenital hip dislocation to be avoided by timely diagnosis at the well-child center]. In 79 children treated in the Sophia Children's Hospital in Rotterdam because of imminent limping due to congenital dislocation of the hip, the contribution of screening tests by physicians of Infant Health Centres to the timely discovery of this disease was examined. When both limitation of abduction of the hip and difference in length of the legs are examined 6 times in the period of 1-8 months of age, the following results in relation to children not or less well screened may be expected: The risk of discovery of the disease at an age when surgery is not excluded, is reduced to one-third. As a result of the shorter delay between discovery and treatment in practice the risk of having to undergo surgery is halved. The risk of discovery at an age when osteotomy according to Salter is required, is nil. In practice the risk of having to undergo osteotomy is reduced to one quarter. Lowering the frequency of the screening tests reduces the contribution. Examination of just limitation of abduction of the hip also appears to reduce the contribution.


[Fatal course of acute appendicitis associated with infectious mononucleosis]. The case history is presented of a 10-year-old boy with a fatal combination of acute appendicitis and infectious mononucleosis, in the literature a particularly rare combination. The boy died of a perforative peritonitis. His appendicitis appeared not to be a complication of the infectious mononucleosis.


[Neonatal withdrawal symptoms following the use of clomipramine during pregnancy]. The case is described of a neonate who suffered from withdrawal symptoms within 24 hours after birth as a result of the use of clomipramine by the mother during pregnancy. The symptoms consisted of increased irritability, alternating hyper- en hypotonia, hyperreflexia, cyanosis and hypothermia. He was treated with clonazepam with good result. Prescription of clomipramine during pregnancy should be restricted to specific cases and the doses should be kept as low as possible. Because the symptoms are withdrawal symptoms, phenobarbital should not be used as treatment, as it increases drug metabolism by the liver causing an even faster decrease of plasma concentrations of clomipramine. Clonazepam is the drug of choice.


[Quality of life of persons with HIV infection in an academic hospital]. Comparison of the quality of life of asymptomatic (n = 24) and symptomatic (n = 20) HIV-infected patients and description of the changes in quality of life during the symptomatic stage. Prospective study. University Hospital Utrecht. Every four months questionnaires on quality of life were completed by 44 of 55 consecutive HIV-infected patients. Physically, asymptomatic HIV-infected patients were better off than symptomatic HIV-infected patients; psychologically, however, both groups of patients showed similar responses. During the symptomatic stage the patients' physical functioning diminished further, but feelings of anxiety or depression showed no marked change; self-evaluations of health conditions became slightly more negative with time.


[Perinatal registration: a pilot study of matching of data from the National Obstetrics Registration and the National Neonatology Registration]. The application of a statistical matching procedure was tested in a pilot study, linking data from the National Obstetrics Registration (hospital-based) with data from the pilot National Neonatology Registration. Linkage appeared feasible, maintaining anonymity of the registered mother-infant pairs. The perinatal database thus formed was suitable for perinatal epidemiological research. Consequently a continuous perinatal database may be formed from the operational home and hospital based National Obstetrics Registration and the National Neonatology Registration which has started on June 1, 1991, allowing ongoing surveillance of perinatal care in the Netherlands.


[Radiofrequency energy as treatment for arrhythmias in patients with accessory atrioventricular pathways]. Evaluation of the use of radiofrequency energy to interrupt accessory atrioventricular pathways. Prospective study. University Hospital Maastricht. The outcome is presented of radiofrequency catheter ablation of accessory atrioventricular pathways in our first 50 consecutive patients, with a total of 54 accessory pathways. All but one patient suffered from symptomatic tachycardias. A catheter electrode was positioned next to the accessory pathway and 30 second pulses of 40 W radiofrequency energy were used to interrupt the connection. Complete block in conduction was accomplished in 44/54 (81%) of accessory pathways. No complications occurred. Success rate, procedure time and radiation dose were found to be related to the location of the accessory connection. The highest success rate was found in left free wall pathways (24/26; 92%), the lowest in right lateral pathways which seldom occur (1/4; 25%). The total procedure took 1-6 hours. The maximal duration of radiographic imaging was 2.5 hours. Although insufficient information on long-term efficacy is available, current results support the use of radiofrequency ablation of accessory pathways in institutions with expertise in the invasive management of cardiac arrhythmias. Technical improvements leading to reduction in procedure time and radiation dose will facilitate acceptance of this technique by patient and operator.


[A patient with chronic mucormycosis].

[A patient with chronic mucormycosis]. Rhinocerebral mucormycosis was diagnosed in a 75-year-old woman with a history of type II diabetes mellitus. This rare opportunistic infection is caused by fungi belonging to the order of Mucorales. The patient had a severe osteomyelitis of the base of the skull, resulting in complaints of headache and diplopia. She was treated with intravenous colloidal amphotericin B, surgical excision, and later with liposomal amphotericin B. She died of respiratory failure. Mucormycosis is usually a rapidly fulminant infection. This patient showed a remarkably chronic course.


[Seroprevalence of hepatitis E in The Netherlands]. At serological testing of 269 blood samples from patients sent in for hepatitis diagnostics and of 275 randomly selected samples from blood donors from all over the Netherlands, eight and five samples, respectively, were found to contain a positive antibody titre against hepatitis E virus (HEV). Follow-up samples could be obtained from three patients: in one patient the anti-HEV IgG titre remained unchanged over a period of 6 months, in one other the titre fell below the limit of detection and in the third, the titre increased in a period of 2 weeks. This patient had developed jaundice after a stay in Bangladesh. It is possible that in some patients, hepatitis E is mistaken for hepatitis A.


[Experience of sexuality in patients with psoriasis and constitutional eczema]. In order to determine the effect of chronic skin disorders on sexuality a cross-sectional study was carried out in the Dermatological Outpatient Clinic of Leiden University Hospital. Fifty-two patients with psoriasis and 25 patients with atopic dermatitis filled in a questionnaire which included items on sexual responsiveness and satisfaction. The response rate was 84%. One-third of the patients, especially those with psoriasis, had problems with dating and starting sexual relationships, and were embarrassed in these relationships. The sexual responsiveness of both male and female patients was below that in the normal population. Women appeared to have more problems in this area then men. Their sexual satisfaction was lower than in the average Dutch population, whereas in men this trend was found to be reversed. Sexual responsiveness did not correlate with the extent of the skin disease or location around genital areas, but was associated with self-esteem and the number of emotional complaints. In the treatment of patients with chronic skin disorders attention should be paid to sexual problems that may arise. Groups that are especially affected are females and young psoriatics who have their first sexual relationship.


[Anal dynamic plastic surgery of the gracilis muscle; a new surgical technique for the treatment of fecal incontinence]. To study the clinical outcome of anal dynamic graciloplasty (gracilis muscle transposition and implantation of electric stimulation device) in a consecutive series of 12 patients. Prospective study. Maastricht University Hospital. Twelve patients with incapacitating faecal incontinence were treated using anal dynamic graciloplasty because they were not amenable to other medical management. The data were analysed with emphasis on the clinical outcome, anal manometry, and gracilis muscle composition before and after electric stimulation. Results were considered significant if p < or = 0.05, using the paired Student's t-test. Eight patients achieved complete faecal continence, one patient still has a previously constructed colostomy and in three patients no faecal incontinence could be achieved, due to infections. Median follow-up is now over 18 months (range 16 weeks-5 years). Anal manometry demonstrated an anal pressure increased from 39 mmHg (without stimulation) to 66 mmHg with electric stimulation (mean increase 27 mmHg (CI: 19-35; n = 12, p < 0.01). Gracilis muscle composition showed an increase of type I relatively fatigue-resistant fibres, capable of prolonged contractions, from 45% before stimulation to 64% afterwards (mean increase 19% (CI: 14-21; n = 8, p < 0.01). Dynamic graciloplasty is capable of replacing the function of damaged or absent anal sphincters. The construction of a colostomy in patients with incapacitating faecal incontinence can be avoided.


[Hepatitis E now also in The Netherlands]. A case report of a male aged 31 who, after a journey to Bangladesh, returned with a disease resembling acute hepatitis A. Closer study revealed a hepatitis E infection. He recovered in slightly over two weeks.


[Multi-infarct dementia in nursing home patients; more comorbidity and shorter life expectancy than in Alzheimer's disease]. A retrospective analysis of the medical charts of 117 patients (50 men and 67 women) with multi-infarct dementia took place. All patients admitted to the psychogeriatric nursing home 'Joachim en Anna' in Nijmegen between 1980 and 1989 were studied. The aim of the study was to obtain epidemiological information and to investigate the prevalence of comorbid conditions, prognosis and mortality. The results were compared with patients with Alzheimer's disease. The patients remained in the institute for 1.4 years and the mean total duration of the disease was 5.3 years. About twenty-five percent died in the first three months of admission. Life expectation, counted from time of admission, was 6 years shorter in comparison with Dutch mortality tables. Morbidity frequently seen at admission included circulatory system diseases and cerebrovascular accidents. The risk factor hypertension was seen in a smaller percentage of patients than expected. During the stay the diseases most frequently diagnosed were respiratory and urinary tract infections, adverse effects of drugs, constipation and chronic ulcers of the skin. About twenty percent of the patients were struck by a (recurrent) cerebrovascular accident or a transient ischaemic attack. Most patients died of dehydration or bronchopneumonia. There was, apart from the diagnosis of multi-infarct dementia, no single patient aspect that could predict a poor prognosis. Nursing home patients with multi-infarct dementia are clearly different from patients with Alzheimer's disease. Time spent in the nursing home and duration of disease are shorter. They have more comorbid conditions, especially of a cardiovascular nature, and they have a poor life expectation.


[Diathermy excision using a metal loop in the treatment of cervical intra-epithelial neoplasms; short-term results in 154 patients]. Intraepithelial neoplasia of the uterine cervix (CIN), proven in colposcopically guided biopsies, can be treated in several ways. With the destruction techniques the lesion is treated by laser evaporation or by cryocoagulation. With the excision methods the transformation zone is excised by cold knife conisation, by laser exconisation or by large loop excision (LLETZ). LLETZ was developed by Cartier in 1977 and can be performed under local anaesthesia on an outpatient basis. In the current investigation 154 women with CIN were treated by LLETZ. In four patients microinvasion was suspected after pathological examination and cold knife conisation was performed, so that 150 patients were available for cytological follow-up after three and six months. After 1989 larger loops and more loops of different sizes were used. Therefore the results in both groups are presented separately. In 22 women CIN residue was found. The treatment in the first period of the study (1985-1988) was effective in 36 of the 55 cases (65%), that in the second period (1989-1991) in 87 of the 95 cases (93%). In the first period the size and endocervical localisation of the lesion significantly affected predict the result of the LLETZ, in the second half of the study these were no longer relevant. Destruction methods lack the possibility of pathological investigation, which is possible with the excision methods. In this way underestimation by the colposcopist of a (micro)invasive carcinoma does not necessarily delay adequate treatment.


[Health complaints in relation to quality of swimming water in participants of a triathlon]. Participants in a triathlon in Alphen aan den Rijn, the Netherlands, reported gastrointestinal symptoms to the local health authority. A study was performed to establish the number of complaints and the relation with the microbiological water quality at the surface water swimming site, which met current standards. An epidemiological survey was carried out with a questionnaire among 629 participants, with non-participating relatives as controls. Faecal samples of patients and water samples were investigated by conventional methods. 439 participants and 217 controls completed the questionnaire. 140 participants had at least one gastro-intestinal symptom and 28 (6.4%) had highly credible gastroenteritis. Participants had an odds ratio for gastro-enteritis of 14.7 (95% CI: 2.39-604.45). Electron microscopic examination in six of 12 patients showed viruses able to cause such symptoms. Water samples showed considerable faecal pollution at the time of the triathlon (geometric mean counts: thermotolerant coliforms 725/100 ml; faecal streptococci 23/100 ml). The most likely source is the effluent discharge of the nearby waste water treatment plant. A surface water swimming site meeting current standards does not exclude health complaints among tri-athletes.


[Repetitive firing in motor nerve endings: modulation by divalent cations, rhythmic activation and cholinergic agents]. The phenomenon of repetitive firing (RG) in motor nerve endings induced by 4-aminopyridine (4-AP) was studied in cut sartorius frog muscle under the voltage clamp conditions. In the presence of 4-AP (1.10(-4) mol/l) one stimulus applied to the nerve induced two end plate currents (EPC) in half of cells studied (n = 35). The elevation of calcium ion concentration up to 5.4 mmol/l or magnesium to 5-9 mmol/l or rhythmic activity (0.05 Hz and above) abolished RF. Substitution of calcium by strontium or barium enhanced RF (the number of EPC during the burst of RF). EPC with very slow time course were observed in some cells in the presence of barium, that disrupted to the burst of RF by repetitive nerve stimulation. Neostigmine, an anticholinesterase agent, increased the number of EPC in the burst of RF, but alpha-bungarotoxin exerted no effect on the RF. The role of calcium and calcium-activated potassium currents in generation and termination of RF in motor nerve endings is discussed.


[Effects of "non-quantal" acetylcholine on the sensitivity of the postsynaptic membrane: action of ouabain and imitation of these effects by exogenous acetylcholine]. Development of postsynaptic potentiation (PSP) and desensitization (DS) caused by "non-quantal" acetylcholine after acetylcholinesterase inhibition was studied by means of ouabain, an agent known to modulate (initially increase and then decrease) the level of non-quantal secretion of ACh. Ouabain had no effect on the MEPC parameters when AChE was active. After AChE inhibition ouabain initially increased the decay time constant of MEPC (tau), i.e. caused postsynaptic potentiation (PSP). This effect of ouabain grew with time between inhibition of AChE and application of ouabain. The PSP stage was followed by shortening of MEPCs decay, due to the development of desensitization (DS), and that process was more pronounced than in control. Applied before AChE inhibition, ouabain had no effect on tau. Thus neither PSP nor DS developed under those conditions. Exogenous ACh (20 nmol/l) applied simultaneously with inhibitor of AChE partially prevented the shortening of MEPCs decay, but decreased the amplitude of MEPC. Applied after MEPCs shortening, exogenous ACh (50 nmol/l) tended to return the initial value of tau. It is concluded that nonquantal ACh produces PSP and DS on the postsynaptic membrane after inhibition of ACh and that the DS persists after cessation of nonquantal secretion for a long time.


[Effect of cat motor cortex on the formation of lateral geniculate nucleus responses evoked by contralateral superior colliculus stimulation]. It was shown in experiments on anesthetized cats that motor cortex (MC) stimulated by single current pulse caused formation of the lateral geniculate nucleus (LGN) response. It was established that changes in formation of LGN response evoked by contralateral superior colliculus (SC) stimulation were observed by condition of the precedence of LGN response evoked by stimulation of the MC. The expressiveness level of that decrease depended on intervals between conditioning cortical and testing tectal stimuli. At the same time the stimulation of the MC by single current pulse caused no changes in formation of the visual evoked potential of LGN. However, a significant decrease of the visual response of that part of the SC which stimulation caused formation of the LGN response was observed under the same conditions. The obtained data permit supposing that MC checks realization of the tectal influences on the LGN function on the tectal level. It is assumed that realization of the effect of the saccadic suppression of the LGN function in which accomplishment, as it was supposed earlier, the SC took part, was controlled by the MC phasic influence.


[Extra-organ sources of parasympathetic innervation of small intestine in the region of ligament of Treitz]. Localization sites of neurons in the dorsal motor nucleus of cat vagus innervating the duodenal-jejunal region and upper part of the jejunum were investigated using the technique of the retrograde axonal transport of horseradish peroxidase. Most part of the neurons was located within the ventrolateral area of the nucleus from +1.0 to +2.7 mm (according to obex). Morphological features of the ganglion nodosum neurons which organize afferent innervation of the intestine were analyzed. It has been shown that the maximal amount of such neurons is concentrated in the medium and caudal parts of the ganglion.


[Dopamine effect on ionic conduction and adenyl cyclase activity in the central nervous system of the pond snail]. The mode of dopamine action (DA) was investigated both on identified neurons (growth hormone producing cells--GHC) and on the membrane fraction of the CNS tissue homogenate. Adenylate cyclase activity (ACA) in the Lymnaea membrane depended on the GTP, stimulated and inhibited by different well known mediators, dopamine action being one of them. DA produced a stimulatory and inhibitory action on ACA. Direction of the DA action depended on the GTP concentration: at lower concentration of the GTP DA was a stimulator of ACA, at higher--an inhibitor. It is shown that inhibitory influence of DA on ACA was prevented by treatment of the membrane of the catalytic subunit of the protein kinase A (cPKA). It is particularly noticeable that inhibitory influence of cPKA-dependent phosphorylation reduced the inhibitory action of ALF4-, a G-protein activator. Effect of DA application on the GHC induced appearance of inward and outward currents through the neuronal membrane.


[GTP-dependent dopamine reception in central nervous system tissues in the pond snail]. Guanosine-5'-triphosphate (GTP)-dependent binding of the agonist D1 dopamine (DA) receptor ligand [H3]-SKF 38393 is described. It is shown that binding of [H3]-SKF 38393 with two different populations takes place in the presence of guanylyl nucleotides, when they are absent--with one population. It is demonstrated using GDP-alpha-P33 binding analysis that the GDP in equilibrium with GTP exchange rate gets higher as a result of activation of DA receptors in the membrane from the mollusc nervous tissues. Influence of the catalytic subunit of the protein kinase A (cPKA) on the [H3]-SKF 38393 and GDP-alpha-P33 is investigated. Obvious influence of the cPKA on [H3]-SKF 38393 binding is not observed, while basal and DA-induced GDP in equilibrium with GTP exchange in membranes of the mollusc nervous tissues is considerably inhibited.


[Switching effect in the system of equilibrium regulation in man]. Postural reactions evoked in human by bilateral vibration of calf muscles were studied under different conditions: sitting without the feet contact with a support; sitting in an unstable position on the edge of the chair; sitting under conditions of the foot contact with different types of supports (rotating disk, suspended platform, etc.); standing with an asymmetrical load applied to the trunk. It has been shown that local vibration of calf muscles can evoke activation not only of the vibrated muscle or of its antagonist (local effects), but also of extensors and flexors of the knee joint (non-local effects), or of the remote muscular groups, involved in different postural synergies. The concrete pattern of muscle activation is determined by several factors, the most important being the relative position of the body links and interaction of feet with a support. The mental image of the body configuration in the system of internal representation is also very significant.


[Responses of medullary and spinal neurons to simultaneous stimulation of two locomotor points]. Responses of neurons in the medulla and cervical segments to simultaneous repetitive (50 pps) stimulation of two locomotor points (LPs) by currents in the range of 1 to 2 thresholds of locomotion were studied. In most cases a neuron responded to stimulation of only one LP. Stimulation of the second LP enhanced usually the firing index of that response, if it was low, diminished it, if it was high and did not influence it, if it was about 0.2. Part of neurons increased the background activity during stimulation of one of LPs though spikes were not locked to stimuli. A sign of influence of the second LP onto that elevation depended on its value. Data about the convergence of inputs from the ipsi- and contralateral midbrain and bulbar LPs on single neurons were obtained too. Possible mechanisms of summation of subthreshold excitation of two LPs during initiation of the locomotion are discussed.


[Effect of monoamines on the responses of frog spinal motor neurons mediated by non-NMDA glutamate receptors]. Adrenaline, dopamine and 5-hydroxytryptamine enhanced fast desensitizing responses of frog spinal motoneurons evoked by L-glutamic acid. Monoamines also enhanced late components of dorsal root EPSP's of motoneurons. These effects of monoamines were prevented by ketamine. Slow in desensitizing responses evoked by L-glutamic acid and EPSP's of motoneurons evoked by stimulation of the reticular formation were not influenced by monoamines.


[Spatial similarity between crystal cells of various agonists of amino acid receptors and the biological effects of these substances]. Space likeness of crystal cells of GABA, glycine, muscimol and taurine has been estimated by special calculation. The relation between the likeness degree of crystal cells and their biological effect on amino acid receptors is marked.


[Recruiting of motor units and changes of their firing rate as mechanisms of muscle contraction control]. Main mechanisms of muscle contraction control: recruiting of motor units and changes of their firing rate are discussed in the review. Relative contribution of these mechanisms at different types of muscular activity (tonic contraction, vibration reflex, locomotion) is considered.


[Pain reception in the skin studied with chemical agents]. Cutaneous C-fibre polymodal mechano-heat (CMH) sensory units of narcotized cats have been studied for their responses to the close-arterial injection of potassium, acetylcholine and methacholine to the saphenous artery in subnoxious and noxious concentrations. Subnoxious chemical stimulation has induced low-frequency excitation of CMH units. The parameters of CMH units firing during subnoxious and noxious chemical stimulation may be used for estimation of effects of local anesthetics. To achieve local anesthesia it is sufficient to inhibit only high frequency responses in CMH units without a complete block of these sensors. With that end in view the use-dependent blockers of nerve excitation are suggested. The use-dependent inhibition of CMH units was found during mechanical stimulation under the action of lidocaine or n-propylajmaline. The mathematical model of C-fibre has demonstrated the key role of slow changes of membrane ionic permeabilities in determining the firing rate elicited by chemical stimulation.


[Focused ultrasound in research on somatic reception]. Focused ultrasound has been used to induce the following skin sensations: tactile and temperature ones; specific and unspecific pain, underskin or deep sensations: tactile sensations and some varieties of pain (muscle, periosteum and so on). It has been established that: somatic reception is attributed to mechanoreception; the same receptive structures are cold and warm ones; ultrasound has the sensibilized action. Sensation differences of corporal and auricular acupuncture points and some accidental skin underskin spots have been investigated.


[The pain sensitivity of the skin in chronic psychoemotional stress in man]. The focused ultrasound has been used for the comparative study of skin sensitivity to pain in 51 healthy men and 64 patients with neurasthenia, natural model of the chronic psycho-emotional stress. The patients showed a distinct tendency to a decrease of the pain threshold, lowered adaptation to the repeated threshold stimulus, sensitization. With the presence of the above-mentioned factors the pain syndrome occurred relatively more often. Taking into account the fact that the focused ultrasound of rather high intensity affects, first of all, C-afferents which are not only cutaneous but visceral nociceptors as well, an assumption is made that changes in pain sensitivity in the neurasthenic patients are not limited by skin but develop also in the inner medium forming the pain syndrome.


[The modulation of the functional properties of the skin thermoreceptors]. The characteristic property of skin cold receptors is the presence of static and dynamic activity with their maximum at any skin temperature. Parallel with the common properties there are some differences in the temperature range of receptors' functioning, frequency of static and dynamic activity, concentration of sensitive receptors on the skin. Mechanisms of these differences are unknown. It is found that the character of skin cold receptors functioning can be changed in individual life of the organism. Some parameters of static and dynamic activity as well as concentration of cold receptors functioning change both with adaptation of the organism to cold and with a rise of the noradrenaline concentration in blood. The reason of adaptive modifications of skin thermoreceptors may be an increase of their sensitivity to noradrenaline observed with adaptation to cold. It can be supposed that the modulating influence of biological active substances is very important in forming activity and sensitivity of skin thermoreceptors.


[The mechanism of the effect of the sympathetic nervous system on skin receptors]. It has been found that smooth muscles play an important role in the mechanism of a sympathetic nervous system effect on the activity of skin receptors. Greater activity of the sympathetic nerve fibres induces higher tension of smooth muscles and thus changes mechanical state of the tissues around the receptors. The latter condition, in its turn, affects the response of receptors to mechanical stimulation. A change in the smooth muscles tension in skin vessels affects the response of receptors to cooling of skin.


[The structure of the impulse activity of cold thermoreceptors at different levels]. Impulse activity of cold fibres (n. infraorbitalis) has been studied in acute experiments on anesthetized rabbits, with an uninterrupted fall of the skin temperature from 39 degrees to 7 degrees C with the rate of 0.8 +/- 0.05 degrees/min. Analysis of interspike intervals (ISI) in a discharge of receptors has shown that histograms of ISI changed several times in the studied range of temperatures, which reflects a change of the discharge pattern. Each cold receptor possesses an individual mode of the response, which permits dwelling on perception of different characteristics of the temperature stimulus by a sum of thermoreceptors.


[The activity of myelinated nerve fibers to heat and burn exposures of the skin]. Activity of myelinated fibres in the n. saphenus was investigated by the crosscorrelation method in the cat's skin stimulated by heat and burn. The decrease of the total nerve activity under the heat action is proved to be related mostly to a change in A beta-fibres. It is shown that pain caused by heating of the skin over 42 degrees C activated A delta-fibres. The results obtained permit solving the problem of the heat information code from the view-point of the flow "pattern" theory.


[Changes in the skin receptor responses to their repeated heat stimulation]. It is known that cooling of skin induces contraction of collagen fibres, which leads to deformation and excitation of mechanoreceptors. The action of moderate heat on the skin depresses or terminates its tonic activity. The collagen fibres in this case stretch out and the skin tension slackens. Yet, intense thermal stimulation up to 48 degrees C results in a greater afferent activity. This effect is associated with the so-called thermoreceptors. It is shown earlier that repeated stimulation by intense heat increases skin sensitivity to this stimulus. The paper reports the results of recording the time in which afferent activity increased under repeated stimulation of the skin at temperatures up to 48 degrees C and, simultaneously, of the skin tension variations. For each heating instance the skin stretched and contracted when its temperature approached the normal temperature, i. e. 30 degrees C. However, by the next heating (there was a 3--min. pause between them) the skin tension failed to restore completely. Multiple heating tests have shown a loss of the skin sensitivity, and the time in which increased afferent activity manifested itself has shortened. These two processes are simultaneous, which permits concluding that they are related.


[The characteristics of the formation of temperature information in afferent units]. Impulse activity of single afferent fibres of the spinal cord dorsal roots of cats was investigated under local mechanical, heat and cold influence on receptive fields of their skin. These influences did not change the frequency of impulsation, but changed redistribution of interimpulse intervals. It is supposed that formation of polyfunctional properties of single afferent fibres is realized due to their polychannel information.


[The regional nature of the temperature sensitivity of human skin]. Thermosensitive points of the man's body skin have been examined in 98 volunteers 20-46 years old living in Alma-Ata in psychophysiological research using temperature and mechanical stimulation. According to thresholds of appearance and quality of sensation two groups of cold-sensitive points and 4 groups of heat-sensitive ones were identified. Receptors of each group located in skin in zones of the greatest concentration. Temperature ranges and the number of sensitive points were compared, which revealed different significance of the skin plots in temperature perception.


[The generator of locomotor activity as the probable modulator of the afferent flow from the thermoreceptors of the skin fields of the flexor and extensor muscles]. The excitability of flexors and extensors of the upper and low extremities was studied in healthy people and in patients with spasticity during local thermostimulation of their receptive fields using H-reflex (HR). In healthy people the HR was inhibited during cooling and was enhanced during warming. Thermostimulation of the contralateral side caused a contraverse reaction. In patients cooling of skin followed the rise of HR. The obtained data show that the condition of the thermoreceptive fields can influence reflex excitability of motoneurons. The character of this influence depends on the initial condition of the locomotor generator.


[The interrelationship of pain and temperature reception in human skin]. Local cooling (14-16 degrees C) and warming (40-42 degrees C) of different crus areas or healthy volunteers have been studied for their effect on pain sensitivity. The latter was estimated by means of the tibialis anterior flexor reflex (FR) and EMC-recording. It was established that changes in FR parameters depended not on the thermostimulus modality, but on its position. The FR was enhanced when the warm or cold stimulus was applied over the ipsilateral tested flexor muscle, and it was mainly inhibited when the thermostimulus was over the extensor or contralateral flexor. An assumption is made that the loss of the temperature modality is caused by convergence of temperature and pain information to the spinal interneurons of the "bimodal type". These neurons change their impulse activity under the effect of both temperature modalities. Different reactions of FR on thermostimulation of different areas of the crus are explained by the locomotor generation control of afferent information.


[The role of skin reception in controlling movements]. Skin receptors have been studied in the aspect of diverse phenomenology of their participation in organization of motor activity: from the protective flexor reflex to fine correcting effects from the skin which covers the muscle and the tendon. Analysis of the character of exteroceptive effects on reflector responses, cyclic motions and arbitrary activity has revealed a distinct determination of the effect, its dependence on localization and intensity of the exteroceptive stimulus, a moment of its application (state of motor centres) and so on. It is shown that the proprioceptive correction of the motion which underlies the ring control of the motion is inevitably added by exteroceptive effects incorporated into the same system due to their convergence to the same neuronal mechanisms. Basic moments of neuronal organization and basic mechanisms of sensory (exteroceptive) correction of motor activity are considered. Proceeding from the results of the author's investigations, the role of the premotor zone (the ventral horn, L6,7) interneurons which are not connected initially with afferents in the processes of sensomotor interaction in polysynaptic ways to the motoneuron is determined. It is supposed that these neurons integrate already selected information and form a discrete premise to output systems.


Selective monocellular necrosis of Hodgkin's/Reed-Sternberg cells and their immunoreactivity to human serum antinuclear antibodies in NS- and MC-types of malignant lymphogranuloma. The selective (apoptotic) necrosis of Hodgkin's cells in malignant lymphogranuloma appears to be etiologically quite different from focal one due to ischemic-vascular causes. The morphology and supposed etiopathogenesis of this cellular lesion, as well as the karyoclastic process-presumably apoptotic in nature-are briefly described and considered as a mechanism leading to cellular regression with subsequent destructuralization and release of DNA-reactive nucleoprotein material in form of free hematoxylin bodies. An original observation of the immunoreactivity of Hodgkin's cells with antinuclear antibodies of human serum in a case of collagenosis is also described.


Studies on the release of interleukin-1 (IL-1), tumor necrosis factor (TNF) and lysozyme from human non-adherent mononuclear cells (nMNC) in vitro after treatment with cisplatin and other biological response modifiers. The supernatants collected from cisplatin, lipopolysaccharide (LPS), muramyl dipeptide (MDP) or recombinant interferon gamma (rIFN-gamma) treated non-adherent mononuclear cells (with NK cell activity) enhanced thymocyte proliferation by a submitogenic concentration of concanavalin A as compared to untreated nMNC. Supernatants collected from cisplatin or rIFN-gamma treated nMNC also demonstrated enhanced cytotoxicity against actinomycin-D treated L929 cells, suggesting that cisplatin or rIFN-gamma treated nMNC release tumor necrosis factor (TNF) into the culture supernatant. On the other hand, supernatant collected from untreated nMNC showed little TNF activity. Treatment of nMNC with cisplatin, LPS, MDP or rIFN-gamma resulted in enhanced release of lysozyme into the culture medium as compared to untreated nMNC.


T-lymphocyte subsets (CD4/CD8 ratio) in breast cancer patients. T-lymphocyte subsets (CD4/CD8 antigen positive cells) were determined in peripheral lymphocytes from 48 patients with breast cancer of different stages by flow immunocytometry with the aid of anti-CD4 and CD8 monoclonal antibodies. A broad individual variability of the CD4/CD8 ratio among both healthy donors and breast cancer patients was observed. The average value of CD4/CD8 ratio decreased in groups as follows: Healthy donors and Stage I patients, Stage IIA, IIB and Stage IV breast cancer patients. These differences were generally statistically not significant. The difference between healthy donors and Stage IV breast cancer patients was statistically significant (p < 0.01), if one exceedingly elevated value of the CD4/CD8 ratio was excluded from statistical evaluation. The average CD4/CD8 value in the group of breast cancer patients with lymph node or distant metastases was lower than that of patients without metastases, but their difference was not statistically significant either.


Effect of aldehydes on free sulfhydryl groups and glycolysis in extracts of Ehrlich ascites tumor cells and mouse liver. Some saturated and unsaturated aldehydes decreased the content of total sulfhydryl (SH) groups and inhibited the aerobic glycolysis in the extract of Ehrlich ascites tumor cells (EATC). These effects were not observed in normal mouse liver cells.


Phosphorus-containing metabolites in anthracycline-resistant murine leukemia P388 cells. The method of 31P nuclear magnetic resonance was used to study in vivo the level of phosphorus-containing metabolites in P388 leukemia cells sensitive or resistant to rubomycin (daunomycin) and its nitroxyl analog-emoxyl. It was shown that decreased content of phosphomonoesters (PME) is characteristic of the resistant strains in comparison with the parent cells. Rubomycin and emoxyl were established not to affect practically the pool of phosphorus-containing metabolites in the cells of the resistant strains, but caused considerable increase of PME level in the cells of the parent strain.


Utilization of determining lipid-bound sialic acid for the diagnosis and further prognosis of cancer. In three types of tumors, rectal carcinoma, large intestine carcinoma and bronchogenic carcinoma, the level of lipid-bound sialic acid (LSA) was determined in blood serum before and after surgical operation. In all the cases, there was a significant increase of LSA content in comparison with healthy controls. Considerable increase in LSA values was observed in patients in relapse after surgical intervention. In contrast to this, in patients with regression the LSA levels were lower as compared with LSA levels prior to the surgical intervention. We believe that the method of determining LSA level could be used not only for the diagnosis of cancer, but also for the prognosis.


Frequent involvement of Ig heavy chain carrier chromosome 12 in translocations in an Ehrlich-derived mouse tumor cell line. Preferential involvement of chromosome 12, the carrier of Ig heavy chain, in structural rearrangements has been documented in an in vitro derivative of Ehrlich-Lettré mouse ascites tumor. Both copies of chromosome 12 have been found to be involved in Robertsonian and tandem translocations with certain other members of the tumor complement in this near-diploid ascites tumor cell line.


The effect of partial hepatectomy on the genotoxicity of aflatoxin B1. II. The influence of partial hepatectomy (PH) on the genotoxic effect of aflatoxin B1 (AFB1) mycotoxin in male Chinese hamsters (Cricetulus griseus) in vivo was studied after a repeated i.p. application of small doses of AFB1 during 8 weeks. The frequency of aberrant cells did not increase after repeated application and persisted throughout the whole period on a relatively stable level. No cumulative genotoxic effect of repeated doses of AFB1 was observed. PH decreased the genotoxic effect of AFB1 only in week 4, while in weeks 6 and 8 no significant differences between hepatectomized and nonhepatectomized animals were recorded.


Chromosomes in Hodgkin's disease--analysis of involved lymph nodes. Chromosome studies carried out using lymph nodes of 47 patients with Hodgkin's disease gave analyzable metaphases in 22 patients of which 16 (72.7%) showed chromosome abnormalities. The modal chromosome number ranged from near-diploidy to near-tetraploidy. Chromosomes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 21 and 22 were involved in trisomy and tetrasomy whereas chromosome 17 was involved in monosomy. Structural abnormalities like deletions of chromosomes 1(p13), 6(q24) and addition of chromatin material to chromosomes 11(q13) and 14(q32) were also detected. The involvement of chromosomes 2, 5, 12, 18 and 21 in numerical abnormalities, and chromosome 14(14q+) in structural aberrations was found to be more frequent in Hodgkin's disease. No clinical correlation could be defined between the various chromosome abnormalities and prognosis of these patients.


Glutathione S-transferase activity in human breast tumors. The level of total glutathione S-transferase (GST) activity was examined in forty-three breast carcinomas (forty tumors from previously untreated patients and three tumors from patients previously treated by chemotherapy), and thirteen benign breast tumors. Cytosolic GST activity was determined according to a spectrophotometric method. Using Student's t-test, significant differences were found between GST levels in these two groups of tumors (p < 0.01). The higher values were found in malignant tumors. The range of values in both malignant and benign tumors was very wide. The relationship between GST activity and hormone receptor status was examined in thirty-three cases for estrogen receptor (ER) status, and thirty-one cases for progesterone receptor (PR) status. The level of hormonal receptors was determined according to the dextran-charcoal technique. No significant difference between the mean levels of GST activity in ER+ and ER-tumors was found (p > 0.4), but the difference corresponding to PR+ and PR-tumors approximated the 1% level of significance. The relationship between total GST activity and clinical or pathological parameters was also studied. Significant difference was found between the mean levels of GST activity corresponding to the groups of patients with non-involved nodes, and those having one or more involved nodes, respectively (p < 0.05). No correlation was found with respect to age (p > 0.2), tumor size (p > 0.2), or tumor grade (p > 0.4). Increased levels of GST activity were found in PR-tumors and in tumors with involved axillary nodes. Both groups of tumors are known to have a poorer prognosis. It was concluded that the significance of GST activity as an additional marker of prognosis must be taken into consideration.


A multivariant study of pituitary adenoma, obtainment of two logistic regression equations as an auxiliary support in the diagnosis of these tumors. A multivariant analysis was carried out in 120 patients with pituitary adenoma (prolactinoma, HGH-secreting adenoma and nonfunctional adenoma) and an equation was obtained concerning the prolactinoma (whose independent variables were age, galactorrhea, impotence, stage, and pretreatment secretion of ACTH) and another one concerning the nonfunctional adenoma (with age evolution time, visual disturbance evolution and galactorrhea as independent variables). These equations are useful in the differential diagnosis. The internal validity of both equations was obtained by calculating the ROC curve and determining sensibility, specificity and predictive values at the "optimum point" of this curve.


Sonography in the diagnosis and therapy monitoring of lymphomas. Multiple ultrasonographic (USG) evaluations of abdomen were performed in 97 patients: 30 with Hodgkin's disease (HD), 60 with non-Hodgkin lymphomas (NHL) and 7 with primary gastric lymphoma (PGL) before or during chemo- or X-ray therapy. In 33% of HD patients USG was normal, while in 63% splenomegaly, in 40% hepatomegaly and in 20% lymph node enlargement were observed. After therapy, in 57% USG was improved and in only 3% of patients worsening was observed. In NHL patients splenomegaly was observed in 70%, hepatomegaly in 60% and lymph node enlargement in 35%. During follow-up, in 49% of patients improvement and in 3% worsening was observed. In 5 patients with PGL no changes were observed, in further 2 patients in Stage IV stomach wall and infiltration of nearest lymph nodes was observed. USG evaluation of abdomen may be useful in staging and therapy monitoring of malignant lymphomas.


Cytokine (IFN-alpha, IFN-gamma, IL-1-alpha, TNF-alpha)-induced modulation of HLA cell surface expression in human breast cancer cell lines. Cytokine-induced modulation of HLA expression on the cell surface of four human breast cancer cell lines was determined by continuous flow immunocytofluorometry with the aid of monoclonal antibodies directed to a non-polymorphic determinant of HLA class I and class II (DR) antigen. IFN-gamma and IFN-alpha were potent inducers of HLA class I in all examined cell lines, with decreasing inducibility as follows: BT-20, ZR-75-1, MCF-7 and MDA-MB-468 cells. HLA class II (DR) antigen was highly inducible by IFN-gamma in ZR-75-1 cells, followed by BT-20, MDA-MB-468 and MCF-7 cells. IFN-alpha increased the cell surface expression of DR antigen only in ZR-75-1 cells. IL-1-alpha induced a moderate level of HLA class I antigen in ZR-75-1, BT-20 and MDA-MB-468 cells, and HLA class II (DR) expression only in ZR-75-1 cells. This pattern of cell line inducibility by IL-1-alpha was similar to that induced by TNF-alpha. Differences in inducibility of HLA antigens on human breast cancer cell lines induced by different cytokines may reflect the differences in cytokine inducibility of the original tumor cells.


Amine oxidase-mediated cytotoxicity of spermine and epinephrine to human myelogenous leukemia K562 cells. The effects of spermine and beta-adrenoceptor agonists (epinephrine, terbutaline and orciprenaline) in the presence and in the absence of fetal bovine serum (FBS) on human myelogenous leukemia K562 cells viability (V) and survival (N/Nc) were examined. Spermine-FBS significantly decreased both V and N/Nc of K562 cells. Aminoguanidine (AG), an amine oxidase inhibitor, and reduced form of glutathione abolished this effect demonstrating that the spermine-FBS action was amine oxidase-mediated. Epinephrine expressed a strong cytotoxicity to K562 cells which was abolished by pargyline, a specific monoamine oxidase (MAO) inhibitor, as well as by reduced form of glutathione. Terbutaline and orciprenaline exerted no cytotoxic activity to K562 cells cultured in FBS-supplemented medium, independently on the presence of spermine. However, terbutaline at concentrations of over 1 mmol strongly inhibited the cytotoxic effect on spermine-FBS. The relationship between cytotoxicity and chemical structure of beta-adrenoceptor agonists was discussed especially with respect to their stability toward oxidation.


Cytochemical study of activated peritoneal macrophages in normal and tumor-bearing rats. Enzyme characteristics of in vitro activated peritoneal macrophages of normal and BP6-TU2 tumor-bearing rats were compared with those of nonactivated macrophages. The activating effect of LPS, IFN-gamma, IL-2, TPA, TNF and Zymosan was assessed by the determination of the activities of alpha-naphthyl butyrate esterase (ANBE), tartrate-resistant acid phosphatase (TRAP), beta glucuronidase (BG) and 5'nucleotidase (5'NT). The used individual activators induced the macrophage enzyme activities in different degrees. LPS, TPA and TNF appeared to be the most effective activators of enzyme activities in macrophages of normal rats. IFN-gamma, IL-2 and Zymosan were less effective. The macrophages of BP6-TU2 tumor-bearing rats were less sensitive to the stimulatory effect of activators with respect to their enzyme activation capacity, except for TRAP activity. The results indicate that enzyme ANBE is an adequate marker of rat peritoneal macrophages. Enzyme TRAP determines the macrophage activation degree more expressively, in comparison with BG and 5'NT. The differences in enzyme activities could be a suitable marker of macrophage activation and might suggest the dependence on the pathway of macrophage stimulation by distinct activators.