Cytoreductive combination chemotherapy for regionally advanced unresectable extramammary Paget carcinoma. Extramammary Paget carcinoma (EPC) is considered to originate from the eccrine and apocrine glands of the adnexal skin of the axilla, vulva or penis, scrotum, or perineum. If immunohistochemical techniques with the use of cytoskeletal markers are applied in addition to histologic examination, EPC lesions are found to be multifocal adenocarcinoma of the adnexal sweat glands. So far, therapeutic approaches have included primary surgery, followed optionally by radiation therapy. It is possible to achieve a cure only when manifestations are detected early and confined regionally. The role of palliative chemotherapy has not yet been assessed in this disease, particularly because of the lack of compliance and follow-up in patients with EPC.


Preoperative and postoperative cytokines in patients with cancer. Changes in tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and granulocyte macrophage-colony-stimulating factor (GM-CSF) were investigated before and after operation in patients with hepatocellular carcinoma (HCC), metastatic liver carcinoma, and gastrointestinal carcinoma. Serum levels of TNF-alpha, IL-1 alpha, and IL-1 beta were high in patients with liver carcinoma (HCC and metastatic liver carcinoma) before operation in comparison with those of normal controls (P less than 0.01). In patients with gastrointestinal carcinoma, serum levels of cytokines, except those of TNF-alpha, were the same as in patients with liver carcinoma. The level of TNF-alpha in patients with gastrointestinal carcinoma was low compared with that in patients with liver carcinoma. Within 1 day after operation, the peak level of TNF-alpha was observed at 15 hours, IL-1 alpha at 18 hours, IL-1 beta at 21 hours, and IL-6 at 24 hours after operation. Subsequently, these cytokine levels peaked again: TNF-alpha at 48 hours, IL-1 alpha at 72 hours, IL-1 beta at 120 hours, and IL-6 at 168 hours after operation. GM-CSF levels increased gradually after operation. Moreover, in HCC, serum levels of TNF-alpha were high in patients with recurrence compared with those without recurrence (P less than 0.01). The difference in IL-1 alpha and IL-1 beta levels between patients with recurrence and those without recurrence can be regarded as significant (P less than 0.01). These results suggest that TNF-alpha, IL-1, IL-6, and GM-CSF may play an important role in the pathogenesis of cancers; TNF-alpha may be especially important as a tumor marker in HCC and metastatic liver carcinoma.


Effect of thapsigargin on cardiac muscle cells. The effect of thapsigargin on the activity of various enzymes involved in the Ca(2+)-homeostasis of cardiac muscle and on the contractile activity of isolated cardiomyocytes was investigated. Thapsigargin was found to be a potent and specific inhibitor of the Ca(2+)-pump of striated muscle SR (IC50 in the low nanomolar range). A strong reduction of the Vmax of the Ca(2+)-pump was observed while the Km (Ca2+) was only slightly affected. Reduction of the Vmax was caused by the inability of the ATPase to form the Ca(2+)-dependent acylphosphate intermediate. Thapsigargin did not change the passive permeability characteristics nor the function of the Ca(2+)-release channels of the cisternal compartments of the SR. In addition, no significant effects of thapsigargin on other ATPases, such as the Ca(2+)-ATPase and the Na+/K(+)-ATPase of the plasma membrane as well as the actomyosin ATPase could be detected. The contractile activity of paced adult rat cardiomyocytes was completely abolished by 300 nM thapsigargin. At lower concentrations the drug prolonged considerably the contraction-relaxation cycle, in particular the relaxation phase. The intracellular Ca(2+)-transients elicited by electrical stimulation (as measured by the changes in Fluo-3 fluorescence) decreased in parallel and the time needed to lower free Ca2+ down to the resting level increased. In conclusion, the results indicate that selective inhibition of the Ca(2+)-pump of the SR by thapsigargin accounts for the functional degeneration of myocytes treated with the drug.


L-glutamate and acetylcholine mobilise Ca2+ from the same intracellular pool in cerebellar granule cells using transduction mechanisms with different Ca2+ sensitivities. Ca2+ mobilisation induced by L-glutamate (Glu) and acetylcholine (ACh) has been studied in cultured cerebellar granule cells using digital fluorescence microscopy. The ability of Glu-receptor activation to mobilise Ca2+ was decreased when [Ca2+]o was lowered to 10 microM (from 1.8 mM). It was enhanced when [Ca2+]i was raised using 25 mM external K+ or by N-methyl-D-aspartate (NMDA), which selectively activates a distinct Glu-receptor subtype. The enhancement was dependent on entry of external Ca2+. In contrast, the ability of ACh receptor activation to mobilise Ca2+ was not affected by these conditions. Furthermore, pretreatment with pertussis toxin inhibited Ca2+ mobilisation in response to Glu-receptor activation without affecting mobilisation in response to ACh. However, activation of both receptors mobilised Ca2+ from a common, thapsigargin-sensitive pool. We conclude that there are differences in the Ca2+ mobilization pathways for the two receptor systems in cerebellar granule cells. The Ca(2+)-sensitivity of this Ca2+ mobilizing Glu receptor may have implications for its function in neuronal synaptogenesis and plasticity.


Different protein kinase C isozymes could modulate bradykinin-induced extracellular calcium-dependent and -independent increases in osteoblast-like MC3T3-E1 cells. Effects of protein kinase C (PKC) on bradykinin (BK)-induced intracellular calcium mobilization, consisting of rapid Ca2+ release from internal stores and a subsequent sustained Ca2+ inflow, were examined in Fura-2-loaded osteoblast-like MC3T3-E1 cells. The sustained Ca2+ inflow as inferred with Mn2+ quench method was blocked by Ni2+ and a receptor-operated Ca2+ channel blocker SK&F 96365, but not by nifedipine. The short-term pretreatment with phorbol 12-myristate 13-acetate (PMA), inhibited BK-stimulated Ca2+ inflow, and the prior treatment with PKC inhibitors, H-7 or staurosporine, enhanced the initial internal release and reversed the PMA effect. Moreover, 6 h pretreatment with PMA caused similar effect on the BK-induced inflow to that obtained with PKC inhibitors, whereas 24 h pretreatment was necessary to affect the internal release. On the other hand, the translocation and down-regulation of PKC isozymes were examined after PMA treatment of MC3T3-E1 cells by immunoblot analyses of PKCs with the isozyme-specific antibodies. 6 h treatment with PMA induced down-regulation of PKC beta, whereas longer treatment was needed for down-regulation of PKC alpha. Taken together, it was suggested that the BK-induced initial Ca2+ peak and the sustained Ca2+ inflow through the activation of a receptor-operated Ca2+ channel, are differentially regulated by PKC isozymes alpha and beta, respectively, in osteoblast-like MC3T3-E1 cells.


Insulin and progesterone increase 32PO4-labeling of phospholipids and inositol 1,4,5-trisphosphate mass in Xenopus oocytes. After a 4-6 h induction period, insulin or progesterone induces Xenopus oocytes to enter prophase of meiosis. During the period of induction, both insulin and progesterone induced an increase in 32PO4 labeling of phosphatidylcholine and phosphatidylinositol. Through a mass assay, we found that insulin and progesterone increase inositol 1,4,5-trisphosphate (IP3) at about 15-30 s, 15 min and at about 2-3 h (0.5 GVBD50) after hormone addition. Since IP3 increases were small (from a basal of 66 to 104 nM), the results agree with prior conclusions that progesterone does not induce a large, cytosolic calcium elevation. Insulin is probably acting through the insulin-like growth factor-1 receptor as insulin concentrations greater than about 50 nM are required to increase IP3.


The p70 tumor necrosis factor receptor mediates cytotoxicity. Tumor necrosis factor alpha (TNF) selectively kills tumor cells, but this specificity is not clearly understood. Two distinctly different cell surface receptors (TNFRs), proteins of 55 kd (p55) and 70-80 kd (p70), mediate TNF action. Mouse TA1 cells are not killed by human (h) TNF, but are killed by mouse (m) TNF alone. Since the mouse p70 TNFR is recognized only by mTNF, these results implicate p70 receptor action in TA1 cell killing. Human HeLa cells have mainly the p55 receptor and are not killed by hTNF alone. When transfected with the human p70 TNFR, HeLa p70 die within 24 hr. HeLa p70 cells also show reduced c-fos and manganous superoxide dismutase induction by TNF. NIH 3T3 mouse fibroblasts are sensitive to only mTNF, but overexpression of the human p70 receptor causes cell death by hTNF and increased sensitivity to mTNF. These results provide a direct function for the p70 TNFR in TNF-induced cytotoxicity.


Multiple, autoreactive TCR V beta genes utilized in response to a small pathogenic peptide of an autoantigen in EAU. The restricted usage of particular T cell receptor beta chain genes in autoimmune disease was studied in LEW rats using T cell hybridomas specific for an immunodominant sequence of bovine retinal S-Ag, which induces experimental autoimmune uveoretinitis. T cell hybridomas from a pathogenic T cell line, R858, specific for residues 273-289 of bovine retinal S-Ag were analyzed in order to determine the contribution of their TCR V beta to self specificity as determined by recognition of the pathogenic epitope represented in the autologous rat S-Ag sequence. Six different, functional TCR rearrangements were expressed by the panel of hybridomas, including two distinct V beta 8.2 rearrangements and functional V beta 10, V beta 14, V beta 19 rearrangements, and an unidentified V beta gene. All hybridomas were Ag specific and reacted both to nonself-peptide derivatives as well as to self-peptide homologues. No unique pattern of peptide reactivity distinguished V beta 8.2+ hybridomas from V beta 8.2- hybridomas; all of the hybridomas were most reactive to the nonself sequences and reacted to self peptide with one to three orders of magnitude less sensitivity. However, all V beta 8.2+ hybridomas were much better responders overall and were activated by lower concentrations of all peptides than were V beta 8.2- hybridomas. Although V beta 8.2 gene usage is strongly associated with autoimmune pathology, these data show that in LEW rats several different TCR V beta genes are utilized in response to a short pathogenic sequence of this autoantigen and show that V beta 8.2 receptors are not uniquely self-reactive. However, the enhanced reactivity to Ag of V beta 8.2+ hybridomas relative to V beta 8.2- hybridomas specific for the same peptide may help explain the close association of V beta 8.2 TCR gene usage with pathogenicity found in autoimmune disease models.


Quantitative determination of the induction of apoptosis in a murine B cell line using flow cytometric bivariate cell cycle analysis. WEHI-231 cells have been used extensively as a model of tolerance induction in B cells. Recent evidence has shown that anti-IgM treatment of WEHI-231 cells resulted in the induction of apoptosis. In this study, using acridine orange staining and flow cytometric analysis, we demonstrated that apoptotic cells are detected as a distinct population of cells separate from the cells in normal cell cycle progression. The validity of analysis gates was confirmed by cell sorting of the apoptotic population versus normal cells and subsequent gel analysis. Using this technique, we have demonstrated that F(ab')2 anti-mu, A23187, or PMA induced apoptosis in the WEHI-231 cells. The addition of LPS reversed apoptotic induction as seen previously with the WEHI-231 cell line. In contrast, however, PMA did not prevent the induction of apoptosis in anti-mu-treated cells. Additionally, we were interested in determining if the induction of apoptosis was restricted to a specific phase of cell cycle. Since growth inhibition results in most cells arresting in the G1 phase of cell cycle, we wanted to demonstrate apoptosis as a G1-dependent event. This was examined with WEHI-231 cells treated with known cell cycle inhibitors. Interestingly, inhibition of cells in each phase of cycle resulted in the induction of apoptosis. LPS was able to inhibit the induction of apoptosis with each of the cell cycle inhibitors except actinomycin D. Furthermore, we have demonstrated that the WEHI-231 cells contain a Ca(2+)-Mg(2+)-dependent preexisting endonuclease.


Cyclic AMP modulation of human B cell proliferative responses: role of cAMP-dependent protein kinases in enhancing B cell responses to phorbol diesters and ionomycin. The ability of cyclic AMP (cAMP) to modulate human B cell proliferative responses and the possible role of cAMP-dependent kinases (PKA) in cAMP modulation of proliferative responses were investigated. The addition of dibutyl cAMP (Bt2 cAMP) or the cAMP-elevating agent forskolin to B cells stimulated by crosslinking surface immunoglobulins (sIg) resulted in a concentration-dependent inhibition of proliferative responses. By contrast, Bt2 cAMP or forskolin enhanced the proliferative responses of B cells after direct stimulation by phorbol myristate acetate (PMA) and the calcium ionophore ionomycin. The inhibition and enhancement of B cell proliferative responses by Bt2 cAMP were observed at different incubation intervals and were not due to temporal shifts of optimal responses. Also, Bt2 cAMP caused only small changes in B cell RNA synthesis compared to modulation of proliferative responses. Exposure of B cells to Bt2 cAMP rapidly activated PKA. Blocking Bt2 cAMP activation of PKA with the kinase inhibitor HA1004 prevented Bt2 cAMP enhancement of B cell responses after direct stimulation by PMA and ionomycin. In reciprocal experiments, the kinase inhibitor H7 resulted in some inhibition of PKC activation but did not inhibit Bt2 cAMP activation of PKA or Bt2 cAMP enhancement of proliferative responses. Other experiments demonstrated that B cells treated with Bt2 cAMP had selective increases in the de novo phosphorylations of two endogenous substrates which reflected PKA activation. Furthermore, concentrations of HA1004 or H8 which inhibited Bt2 cAMP enhancement of proliferative responses also inhibited PKA phosphorylations of these substrates whereas H7 did not. Thus, elevations of cAMP can enhance or inhibit human B cell proliferative responses to different stimuli and the activation of PKA is important for cAMP enhancement of certain responses.


Extent of gamma delta T cell involvement in the pneumonia caused by Sendai virus. The prevalence of gamma delta T cells in bronchoalveolar lavage (BAL) populations recovered from the respiratory tract of young, adult C57BL/6J mice infected intranasally (i.n.) with Sendai virus has been assessed by FACS-phenotyping, and by probing cytocentrifuge preparations for expression of TCR gamma mRNA. The surface gamma delta TCR+ set comprised from 5 to 20% of the inflammatory lymphocytes in sequential samples taken throughout the course of this nonfatal viral pneumonia. The BAL population also contained numerous cells expressing mRNA for C gamma 1/2 and C gamma 4; the C-regions were utilized for productive TCR gene rearrangement. Sorting the lymphocytes from the BAL established that greater than 90% of both the TCR gamma and TCR beta mRNA partitioned to cells with the appropriate surface TCR phenotype, while less than 7% of the TCR mRNA+ cells in the total inflammatory exudate were phagocytes that engulfed latex particles. Both the frequency and the total numbers of the gamma delta TCR+ and TCR gamma mRNA+ cells were increased in mice depleted of alpha beta T cells by in vivo treatment with mAbs to CD4 and CD8, indicating that the CD4+ and CD8+ alpha beta and CD4-8- gamma delta T cell subsets may operate independently in this virus disease. The C gamma 1/2 mRNA phenotype predominated throughout the course of the active infection, with a transition to maximal prevalence of the C gamma 4 mRNA+ set occurring very late (Day 20) in the resolving inflammatory process. Large numbers of macrophages expressing mRNA (greater than 50%) for a mammalian 65-kDa heat shock protein (hsp65), a possible target for some of the gamma delta T cells, were present early (Days 5-7) and remained at lower levels (less than 20%) thereafter. These hsp65 mRNA+ macrophages were much less apparent in BAL populations from mice depleted concurrently of the CD4+ and CD8+ T cell subsets, indicating that exposure to Sendai virus alone is not the major factor inducing the transcription of this endogenous gene. These experiments thus establish that gamma delta T cells are a minority of the infiltrating lymphocytes in Sendai virus pneumonia and provide new insights into the spectrum of hsp65 mRNA and TCR gamma mRNA expression during an inflammatory process.


Neutrophil short-lived oxidant production: enhancement following onset of sepsis-induced lung injury. Generation of superoxide anion (O2-) by activated neutrophils (PMN) is implicated in the pathogenesis of endothelial cell injury in sepsis. To quantitate this phenomenon we studied the kinetics of O2- production by PMN following in vivo and in vitro exposure to Pseudomonas aeruginosa. PMN were isolated from young swine before and after a 1-hr infusion with 5 x 10(8) organisms/ml at 0.3 ml/20 kg/min. Baseline PMN were studied in an in vitro system where 1 x 10(6) porcine PMN were incubated with live Pseudomonas for 1 hr at 37 degrees C. Neutrophils from septic pigs exhibited a significantly increased (P less than 0.05) initial rate of O2 production, which was 125% greater at 2 min following initial stimulation than saline controls (P less than 0.001). Neutrophils exposed in vitro displayed a similar enhancement of the rate of O2- production; however, the rate was 3.6 times greater than that noted in vivo. The in vivo change in PMN oxidant generation was associated with a rise in both extravascular lung water (EVLW) and increased bronchoalveolar lavage protein (BAL-P) content. These data suggest that sepsis-induced acute lung injury is accompanied by "priming" of circulating PMN; however, important factors are present in the circulation in sepsis that serve to attenuate the damaging potential of PMN oxidant species.


Methionine in protection of hemorrhagic shock: role of oxygen free radicals and hypochlorous acid. Various mechanisms may exist for activation of polymorphonuclear (PMN) leukocytes during hemorrhagic shock and reinfusion. During activation of PMN leukocytes, hypochlorous acid (HOCl) is produced in addition to oxygen free radicals. We studied the effects of hemorrhagic shock and reinfusion on cardiac function and contractility, oxygen free radical producing activity of PMN leukocytes (PMN chemiluminescence), and serum and cardiac tissue malondialdehyde (MDA), a lipid peroxidation product, with and without methionine (quencher of hypochlorous acid) in anesthetized dogs, in order to assess the role of hypochlorous acid in depression of cardiac function and contractility in hemorrhagic shock. The dogs were divided into two groups: group I, hemorrhagic shock (2 hr) followed by reinfusion (2 hr); and group II, hemorrhagic shock and reinfusion similar to group I but methionine (30 mg/kg i.v.) was administered before bleeding, before reinfusion, and after 1 hr of reinfusion in this group. Mean arterial pressure (mAo), mean pulmonary arterial pressure (mPAP), index of myocardial contractility (dp/dtmax), and cardiac function (stroke volume index [SVI], left-ventricular work index [LVWI]) decreased significantly during shock and the decreases were similar in both groups. The indices of myocardial contractility which are independent of pre- and/or afterload ([dp/dt]/IIP and [dp/dt]/IIP/CPIP) were affected to a lesser degree than the other indices of myocardial contractility (dp/dtmax) during shock and reinfusion. However, the systemic and pulmonary vascular resistance increased significantly in both groups. Postinfusion recovery of cardiac function and contractility in group II was greater than in group I. Cardiac function and contractility after reinfusion returned to preshock levels initially followed by a decrease below the preshock values in group I. However, these parameters remained at or above preshock levels after reinfusion in group II. Cardiac tissue MDA levels were higher in group I, as compared to those in control dogs. The tissue levels of MDA in group II were lower than in group I but similar to those of control. The serum MDA did not change significantly during shock and reinfusion in either group. Although there were increases in the serum MDA after reinfusion in group I, they were not significant. While the chemiluminescent activity of PMN leukocyte increased significantly in group I, this activity decreased significantly in group II during shock and reinfusion. Methionine in in vitro studies did not affect the oxygen free radical producing activity of PMN leukocyte. These results suggest that hypochlorous acid is produced during shock and reinfusion. The decrease in the cardiac function and contractility after reinfusion may be due to hypochlorous acid.


Homogeneous trinder-coupled assay for the determination of glucose-6-phosphatase activity in tissue extracts. We describe an automated, homogeneous, glucose oxidase-coupled method for the determination of glucose-6-phosphatase activity in tissue extracts. The method is based on measurement of the rate of glucose formation by the Trinder reaction, in which the end product is a quinoneimine dye which absorbs maximally at 505 nm and has a molar extinction coefficient of 5700. The incubation mixture contains 20 microL of tissue extract, 25 microL of 0.5 M phosphate buffer, pH 7.0, 175 microL of Trinder/glucose-6-phosphate reagent, and 30 microL of distilled water. After a delay period of 15 min, to exhaust any glucose endogenously present in the extract, glucose production from glucose-6-phosphate is monitored at 505 nm for 5 min in a centrifugal analyzer. The Km was 13 mM over a 10-fold range in glucose-6-phosphate concentration and the reaction was linear up to about 250 U/L. Within-run CV of the assay at activities of 48 and 190 U/L ranged between 2.5-5.0%. The between-run CV at 190 U/L was 5.1%.


Putative melatonin receptor in human spermatozoa. Melatonin is present in human semen, and may affect sperm motility. The presence of melatonin receptors on spermatozoa has not yet been reported. Detection of melatonin-binding sites may be limited because of the masking of such sites by sialic acid. Spermatozoa were obtained from eligible human donors, incubated with neuraminidase to remove sialic acid residues, and saturation binding assays were carried out using 2-125I-melatonin as a receptor probe. Consistent 125I-melatonin binding could only be obtained after spermatozoa were treated with neuraminidase. Scatchard analysis revealed a low-affinity binding site (ML-2) with a Kd value of 127 +/- 6 nM and a Bmax of 25 +/- 4.5 fmol/mg protein. These results present evidence of melatonin-binding sites in spermatozoa. Sialic acid possibly regulates the binding of melatonin to these sites.


Amplification of intermediate-size DNA sequences from formalin and B-5 fixed tissue by polymerase chain reaction. Retrospective analysis of DNA from paraffin-embedded fixed bone marrow biopsy specimens is possible if preceded by amplification of the DNA sequences of interest by the polymerase chain reaction (PCR). These fixed specimens yield degraded DNA that may not be suitable for direct analysis by conventional digestion and hybridization methods. This limitation is circumvented by PCR amplification and subsequent analysis of the amplified products. The model used in this study is the amplification of a 725 base-pair (bp) beta-globin gene sequence encompassing the sickle-cell anemia point mutation, followed by Cvn I digestion. The beta A beta A, beta A beta S, and beta S beta S genotypes are derived from analysis of the allele-specific digestion patterns. Two fixatives were compared: neutral-buffered formalin and a mercury-based fixative (B-5) routinely used for bone marrow biopsies. DNA extracted from B-5-fixed bone marrow specimens was found to be more degraded than DNA from neutral-buffered, formalin-fixed bone marrow aliquots from the same specimens. PCR amplification of the 725 bp beta-globin gene sequence was successful with DNA from formalin-fixed bone marrow specimens, but not with DNA from B-5-fixed identical specimens. Analysis of the amplified product by Cvn I digestion resulted in correct genotype derivation for all patients, normal controls and positive controls (patients diagnosed with sickle-cell anemia or trait). These results indicate that intermediate-size DNA sequences can be amplified and analyzed when DNA is extracted from formalin-fixed bone marrow specimens.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of serum bilirubin on determination of uric acid by the uricase-peroxidase coupled reaction. We examined the possible effect of different bilirubin species, including unconjugated (Bu), sugar-conjugated (Bc), and authentic delta bilirubin (Bd) isolated from serum, on the direct enzymatic measurement of uric acid by using the uricase (EC 1.7.3.3) and peroxidase (EC 1.11.1.7) coupled reaction. Bc, isolated from human bile, produced the most interference with uric acid determination. Although the presence of human serum albumin reduced interference by Bu and Bc, albumin-bound Bc complex still produced greater interference than Bu. Interference with the peroxidase reaction by Bc covalently bound to serum albumin (Bd) was less than that by Bu. We examined this phenomenon by using serum-isolated Bd obtained by ammonium sulfate precipitation and ultrafiltration and by using commercially available ditaurobilirubin (DTB) and chemically synthesized Bd (via Woodward's reagent, WBd) as surrogates for bile-isolated Bc and natural Bd, respectively. DTB produced the same amount of interference as natural Bc, but the interference produced by DTB in the presence of serum albumin was not the same as that produced by natural Bc with albumin. Our synthetic Bd appears to be a reliable surrogate for natural Bd in testing for bilirubin interference.


GABAA agonists as targets for drug development. 1. Agents with selective actions on bicuculline-sensitive GABAA receptors have been developed by systematically restricting the conformational mobility of the GABA molecule. 2. THIP, a bicyclic isoxazole that represents GABA held in a relatively rigid and partially extended conformation, is an analgesic of potency comparable to that of morphine. THIP represents a lead compound for a novel series of analgesics acting independently of Naloxone-sensitive opiate systems. 3. ZAPA, a conformationally-restricted analogue of GABA containing an isothiouronium moiety, is a selective agonist for low affinity GABAA receptors and is a lead compound for the development of a novel series of anthelmintics. 4. (+)-TACP, a cyclopentane analogue of GABA, may activate a different subclass of GABAA receptors from THIP. 5. Pharmacological, molecular modelling and molecular biological studies provide evidence for a heterogeneity of GABAA receptors which might be exploited for drug development.


Clonal frequency analysis of B cells producing pathogenic anti-DNA antibody-associated idiotypes in systemic lupus erythematosus. In order to identify the mechanism responsible for autoantibody production in systemic lupus erythematosus (SLE), B cell repertoires associated with anti-DNA idiotypes were explored by a limiting dilution analysis using Epstein-Barr virus (EBV) transformation methods and ELISA spot assays. The frequencies of B cell clones producing antibodies to DNA and to conventional antigens, tetanus toxoid, dinitrophenyl, or keyhole limpet hemocyanin were higher in active SLE compared to those in inactive SLE and in normal subjects. In addition, there was a disproportionate increase in anti-DNA antibody- and anti-DNA idiotype (Id)-producing clones at the precursor cell levels as well as at the mature cell level. On the other hand, numbers of anti-Id clones against anti-DNA-Id, termed 0-81 Id, were markedly increased at inactive stages of the disease but not at active stages. These were confirmed by serial studies in some patients with SLE. These results support a two-step mechanism for autoantibody production, in which initial polyclonal activation is followed by an antigen-driven process, and indicate an alteration of the precursor B cell repertoire in SLE, which may also associate with a preferential expansion of anti-DNA clones.


Function of amyloid and amyloid protein precursor. A short review is given of the functions of amyloid (beta/A4) and its precursor protein (APP). The possible relationship between amyloid deposition and dementia is discussed.


On chorea: possible neuronal mechanisms. The mechanism of generation of choreic movements is a rather difficult issue to be elucidated, chiefly due to the lack of a good animal model. Recently we have succeeded to reproduce choreic movements in monkey by using kainic acid lesion of the striatum and the administration of L-dopa. Based on the morphological and biochemical findings of monkey brains, we proposed the hypothesis for the mechanism of choreic movements to be the presynaptic "activation" of the nigro-striatal dopaminergic pathways rather than the postsynaptic dopaminergic receptors in the striatum. This hypothesis coincide well with the clinical and clinico-pharmacological experience in Huntington's disease. The possible mechanisms of the dopaminergic "activation" are discussed.


Cerebral information processing estimated by unpredictability of the EEG. Processing of complex information by the brain desynchronizes neuronal cells and therefore increases the unpredictability of the EEG, rather than its amplitude or power. A model of this mechanism describes the EEG as being composed of both an unpredictable fraction and a fraction that can be predicted from the past EEG. The model realistically simulates EEG of several behavioural states and suggests a simple algorithm for the computation of EEG predictability (values between 0% and 100%). Applications in sleep analysis and event-related desynchronization demonstrated that the algorithm is more accurate and artifact-resistant than the usual (spectral) power methods.


Copper-zinc superoxide dismutase in cerebrospinal fluid: implications for oxygen-radical stress in the central nervous system. We determined the concentration of copper zinc superoxide dismutase (CuZnSOD) in cerebrospinal fluid (CSF) and plasma of 36 persons without neurological illness or with various central and peripheral nervous system disorders not supposed to generate abnormal radical formation. The CuZnSOD concentration in CSF was significantly higher compared with plasma, suggesting the presence of a high oxygen-radical load on the central nervous system. Our data may be considered to reflect normal values.


The Multiple Sleep Latency Test: a paradoxical test? The Multiple Sleep Latency Test (MSLT) has gradually gained acceptance as an objective equivalent of the complaint of sleepiness. The history of this test and questions considering the validity of the MSLT in different situations are discussed.


The smile in anencephalic infants.

The smile in anencephalic infants. During the period 1947-1959 twelve new-born mero-anencephalics were observed, who survived for more than 1 day after birth. Two even lived for 20 and 237 days, respectively. In 4 of the 12 children studied touching or slight pressure, and also faradic stimulation of various spots of the cerebro-vascular area were invariably followed by a facial expression which was very similar to smiling. Movies of it were shown to groups of impartial observers. In 78% the facial expression was judged to be a smile, a laugh or a grin. The neuroanatomical finding of a largely intact pontine tegmentum as being the most rostrally situated identifiable structure of the brainstem, has led to the hypothesis that the neural mechanisms underlying the smile are localized in the pontine tegmentum.


Inclusion body myositis: its relative frequency in elderly people. Inclusion body myositis (IBM) is a distinct, steroid resistant, form of inflammatory myopathy. Its recognition is the more important because of the preponderant occurrence in the elderly, in whom steroid treatment is hazardous. Since the relative frequency of IBM among inflammatory myopathies in the elderly is undetermined, we retrospectively studied its frequency among all our patients over 50 years, diagnosed between 1980 and 1991 with inflammatory myopathy. Nine of 15 patients with inflammatory myopathy appeared to suffer from IBM. In a further 2 patients this diagnosis was strongly suspected. We conclude that IBM is the most frequent inflammatory myopathy in the elderly. This observation warrants restraint with steroids in the management of inflammatory myopathy in the elderly.


Topographical aspects of cerebellar degeneration. Cerebellar Purkinje cells are arranged in longitudinal zones which differ in their connections and their biochemical properties. The significance of these patterns for the distribution of cerebellar degeneration is discussed.


Becker-type muscular dystrophy. Report of a family with one postmortem study. Becker-type muscular dystrophy (BMD) is reported in two brothers. In one of the patients, the molecular demonstration of an in-frame deletion of exons 45, 46 and 47 has confirmed the clinical and pathological diagnosis of BMD. The autopsy of the other patient revealed mild neuronal losses in the anterior horns at C8, lumbar and sacral levels of the spinal cord. Mild neuronal losses in the spinal cord may explain the mixed type of neurogenic-myogenic features in the skeletal muscles of adult BMD patients.


Aberrant nerve fibres within the central nervous system. Three cases of aberrant nerve fibres in the spinal cord and medulla oblongata are described. The literature on these fibres is discussed and their possible role in regeneration. Different views on the possibility of regeneration or functional recovery of the central nervous system are mentioned in the light of recent publications, which are more optimistic than before.


Analysis of intention tremor.

Analysis of intention tremor. A marked effect of stereotaxic thalamotomy on intention tremor is described and a neurophysiological interpretation is offered. Tremor-generating activity seems to start in the ventral intermediate nucleus (VIM) of the thalamus, as revealed by recording of the unitary activity through a microelectrode at the tip of the insertion needle, after diminution of facilitatory input due to pathology of the cerebellum or its efferent pathway to the cerebrum. This secondary change within the VIM and the loss of facilitatory input leads to an intention tremor as one of the cerebellar symptoms seen in various neurological diseases.


Reflexes and neurologists.

Reflexes and neurologists. Neurologists are particularly concerned with elicitation of reflexes, interpret them as indicative of levels of the nervous system and its development or dissolution. This article reviews selected aspects of reflex action. No longer simply reflexology, clinical neurology will still make new observations about reflexes and, more relevant, clinical neurologists will enjoy the process. The breadth of interests of George Bruyn is a permanent reminder to future neurologists of what complexities can be constructed on basic observations such as have been done on "our" reflexes.


Some clinical aspects of late onset parkinsonism. Thirty-six parkinsonian patients were selected by age of onset of over 70 and a minimum of five years duration of illness. The mean age of onset was 73.5 years and 30 patients were still alive after a mean of 7.2 years. We found that late onset Parkinson's disease has a relatively benign course with more "axial symptoms" especially dysarthria, freezing and postural instability. Dyskinesias and fluctuations are rare and dementia occurs in few patients in spite of their old age.


Psychiatric symptoms and mental changes as major features of multiple sclerosis. A patient is presented with clinically and laboratory supported definite multiple sclerosis who developed severe depression followed by mental deterioration. Magnetic resonance imaging MRI demonstrated multiple hemispherical lesions. It is suggested that the psychiatric and cognitive signs and symptoms observed in this patient are due to severe cerebral demyelination.


Cervicogenic headache: the controversial headache. Cervicogenic headache is characterized by unilaterality without sideshift, and the pain attack starts in the neck, in contradistinction to what is the case in common migraine. Signs of neck involvement (e.g. reduction of the range of motion; mechanical precipitation of attacks; ipsilateral, diffuse arm/shoulder pain) are typical in cervicogenic headache but not in common migraine. These and many other features aid in distinguishing these two headaches.


How to prevent the retiring brain from degenerating. In organs other than the brain, cell activation seems to increase "wear and tear", e.g. by increased free-radical formation, and so to cause an increased rate of aging. However, activation of nerve cells within the physiological range seems to lead to maintenance of neurons during aging, possibly by preferentially stimulating the action of protective mechanisms such as DNA repair. This "use it or lose it" principle might explain why in aging and neurodegenerative diseases certain neurons degenerate while others do not, and why recovery of various neuronal systems during aging has been obtained by restoration of the missing stimulus. Consequently, neuronal activation might provide a means of prolonging its optimal function for the full length of our natural life span, also following retirement.


Neurocysticercosis and epilepsy in Peru. This study was carried out to determine the prevailing type of epilepsy in neurocysticercosis. We also evaluated if it could account for the predominance of generalized epilepsy in Peru. We studied the records and EEGs of 49 cases of neurocysticercosis, representing 5.9% of all hospital admissions. Cysticercosis was diagnosed using clinical, blood, CSF (complement fixation, ELISA, immunoblot) and CT scan criteria. We found 49 epileptic patients. Their type of epilepsy was as follows: 35 subjects had generalized epilepsy and 14 had partial epilepsy (5 motor partial, 5 complex partial, both with secondary generalization and 4 motor partial). All but 3 patients were over 25 years old (mean 33 years). We conclude that generalized epilepsy is frequent among cysticercosis patients and that it may account, partially, for the predominance of generalized seizures in Peru and in other areas of South America where cysticercosis is endemic.


Neurological disorders in the Roman Empire, as reported by A. Cornelius Celsus. The first author on medical history and compiler of medical knowledge was, in all probability, A. Cornelius Celsus. Uncertainties about his real profession and background are discussed. Some details of his treatise on history, anatomy, general symptoms and signs, and treatment of medical disorders, as far as these might be of interest to a neurologist, are presented.


Magnetic stimulation of the brain: starting or stopping. A very brief magnetic pulse is able to stimulate cortical neurons through the intact scalp. It can elicit movement of a limb by activation of pyramidal cells either directly or via interneurons. When making a voluntary movement, a corresponding program of the task is thought to be compiled beforehand. In patients with ideomotor apraxia who can not perform a task, a lesion of the left hemisphere is frequently found. A magnetic cortical stimulus given directly before a movement is executed is known to delay the onset without altering the pattern. When it will become feasible to deliver a localized stimulus to one hemisphere, this will induce a temporary pause in that area and thus simulating a lesion in intact brain. In this way information can be gathered on the localization of voluntary action in intact brains.


The neuropathology of hereditary spastic paraparesis. Hereditary spastic paraparesis or Strümpell's disease is a genetically determined neurodegenerative disorder in which the signs and symptoms are predominant in the legs. Inheritance is usually autosomal dominant and in a minority recessive. Neuropathological study reveals a degeneration of the corticospinal tract decreasing from lower lumbar to cervical level and of posterior columns increasing from lumbar to upper cervical level as well as degeneration of the spinocerebellar tracts in approximately 50%. The nature of this nucleo-distal central axonopathy and clinicopathological discrepancy for posterior columns, as well as the limits of the pathological process are poorly understood.


Pitfalls, fallacies and false positive rates. True and false positive rates of auditory and visual evoked potentials, as well as multi-modal evoked potentials, were assessed in groups of 30 multiple sclerosis patients and 19 healthy age-matched subjects. Sensitivity (true positive rate) generally proved to be high confirming published reports. False positive rates, which have not been extensively reported previously, proved to be unacceptably high. This held for two different abnormality thresholds (2 or 3 SD above the mean). The explanation for this proved to lie in the nature of an evoked potential test, which may be regarded as a combination of multiple independent components. The combination method, used to label the evoked potential test as normal or abnormal, governs the false positive rate. When the abnormality of at least one component is sufficient to label an evoked potential as abnormal, then the high false positive rate soars with the number of components. To increase the value of clinical evoked potential studies, it is advised that attention is paid to combination methodology, and that true as well as false positive rates should be directly measured.


Cerebrotendinous xanthomatosis.

Cerebrotendinous xanthomatosis. Cerebrotendinous xanthomatosis (CTX) is a familial sterol storage disease based on an inborn error of metabolism involving bile acid synthesis. Predominant clinical features are a chronic progressive neurological syndrome, mental deterioration, bilateral cataract and xanthomas. The presence of xanthomas usually leads to the diagnosis, and the reverse is probably also true: without xanthomas the diagnosis will often not be made. CTX may therefore be less rare than commonly thought, and the incidence of xanthomas in CTX may be overestimated. Four cases without xanthomas among the presenting symptoms are described, and the relevance of xanthomas in CTX is discussed.


The migraine-dopamine link: do migraine and Parkinson's disease coexist? The role of the dopaminergic system in the pathogenesis of migraine was studied by evaluating the course of migraine after the onset of Parkinson's disease (PD) in 5 migraineurs. The course of migraine in patients with a family history of migraine was not changed after the onset of PD. On the other hand, in migraineurs without a family history, the migraine attacks either subsided or became shorter and less severe after the onset of PD. These findings may suggest a different role of the dopaminergic system in migraineurs with and without a family history of migraine, and call for a larger survey.


Magnetic resonance imaging of the so-called cerebral cryptic angiomas. Cerebral cryptic angiomas are vascular malformations with variable histological appearance, but with similar radiological features. Angiography does not usually visualize the lesion. Computer tomography often detects the malformation, but frequently fails to make classify correctly. With magnetic resonance imaging (MRI) the cryptic angioma is studied best on T2 weighted images. The pattern of signal intensities differs both among and within the lesions. Evidence of small hemorrhages of different ages and flow phenomena are seen in all malformations. A total of 51 angiomas were demonstrated in 38 patients by MRI (excluding one patient with a very large number of angiomas). Enhanced or plain CT scans depicted respectively 16 and 6 lesions. In one case angiography was the only way to detect an angioma. Currently, MRI is the most sensitive method for the detection of cerebral cryptic angiomas.


Arachnoid cysts of the middle cranial fossa. Surgical management for headache. To answer the question whether headache in association with a middle cranial fossa arachnoid cyst without other signs warrants surgery, an analysis of five cases is performed. Three of 5 patients became free of symptoms, compared with 15 of 19 (79%) patients that have been collected in the literature. Both failures were treated with a low pressure cysto-peritoneal shunt without fenestration. They complained of headache resembling postural headache after lumbar puncture. Surgical treatment in the form of a craniotomy with fenestration can be advised, but is major neurosurgery. Alternatively, the merit of a cysto-ventriculo-peritoneal shunt should be considered in this group of patients.


The spectrum of motor disorders in Huntington's disease. EMG of involuntary muscle contractions and their correlation with clinical pictures in Huntington's disease disclosed a series of motor disorder from chorea to parkinsonism. Irregular brief contractions appearing reciprocally in flexor or extensor muscles were observed in typical chorea with hypotonia. Tonic nonreciprocal contractions appeared in the rigid form. In athetoid movement or dystonic postures, more slowly nonreciprocal fluctuating contractions appeared. In some cases phasic contractions changed from a reciprocal to nonreciprocal pattern by psychic stress. In contrast to the activation of motoneurons in choreatic movements, involuntary brief suppression of voluntary contraction appears in typical chorea. Difference in involuntary movements and muscle tone may result from quantitative differences in involvement of striatal neurons which are the origin of parallel pathways proposed by DeLong and colleagues.


Neurotuberculosis: a review.

Neurotuberculosis: a review. Tuberculosis is still a major cause of serious illness in many parts of the world. CNS involvement has frequently been found secondary to tuberculosis elsewhere in the body, particularly the lungs. The disease manifests itself as meningitis, tuberculoma and/or spinal tuberculosis. The presence of tuberculosis elsewhere in the body favors the diagnosis although its absence does not exclude it. While tuberculous meningitis is a disease of childhood, tuberculomas and spinal tuberculosis are invariably an adult manifestation. The great majority of patients with neurotuberculosis are diagnosed and treated early because of characteristic clinical, imaging, and CSF findings. Clinical response to antituberculous therapy in all forms of neurotuberculosis is excellent if the diagnosis is made early before irreversible neurological deficit is established.


Interphase cytogenetic analysis of gliomas. Interphase cytogenetics is the application of nonradioactive in situ hybridization with chromosome-specific DNA probes to interphase nuclei. The possibilities and limitations of this new technique for the study of chromosomal aberrations in gliomas are discussed.


The localization of memory.

The localization of memory. MRI showed severe lesions, thought to be specific for the Wernicke-Korsakoff syndrome, in an alcohol dependent patient with an excellent memory. The morphological abnormalities thought to be typical of Wernicke-Korsakoff syndrome might be features of chronic alcoholism and malnutrition. This contention has important implications for the localization of memory functions. Recent literature on the anatomical basis and mechanism of memory is reviewed. Memory probably resides in multifocal neural networks rather than in specific anatomical sites.


Amantadine as N-methyl-D-aspartic acid receptor antagonist: new possibilities for therapeutic applications? The N-methyl-D-aspartic acid (NMDA) receptor is an intriguing target for the development of drugs with anti-Parkinsonian activity as well as with protective actions against degenerative processes induced by brain ischemia. Amantadine is used in the treatment of Parkinson's disease without a well established mechanism of action. We show here that amantadine inhibits, in a non-competitive way, the NMDA receptor-mediated stimulation of acetylcholine release from rat neostriatum in vitro in "therapeutic" (i.e., low micromolar) concentrations. This indicates that amantadine might exert its anti-Parkinsonian effect via blockade of NMDA receptors. Sustained stimulation of NMDA receptors induces so-called excitotoxicity. Recently, it was demonstrated that amantadine is able to inhibit NMDA induced cell death in a neuronal culture. On the basis of these findings it seems worth investigating if amantadine is also able to protect against neurodegenerative processes caused by brain ischemia in vivo.


Postural instability in Parkinson's disease. Postural instability is one of the most disabling features of Parkinson's disease. Many factors contribute to balance impairment of Parkinson patients, including disturbed postural reflexes and poor control of voluntary movement. Additional factors which place Parkinson patients at risk for falls are side-effects of medication (dyskinesias), the poor response of postural instability to antiparkinsonian medication, orthostatic hypotension, gait abnormalities, muscular weakness in leg muscles and superimposed age-related changes such as reduced peripheral sensation. Future studies should not only investigate means of preventing falls in unstable patients, but should also be directed towards development of new treatment. Because accumulating evidence indicates that postural instability is at least partially related to non-dopaminergic lesions, these novel therapeutic approaches should be aimed at overcoming non-dopaminergic neurotransmitter deficiencies.


Reversible mental deterioration and neurological disturbances with o,p'-DDD therapy. A patient with serious neurological and neuropsychological side-effects of a 2-year treatment with 1,1-dichloro-(o-chlorophenyl)-2-(p-chlorophenyl)ethane (o,p'-DDD) for adrenal carcinoma showed complete recovery after discontinuation of the drug. Studying a larger number of patients during and after long term treatment with o,p'-DDD is indicated. If results of this report are confirmed, therapy should not be discontinued even if serious side effects occur.


Neuropathological findings in cerebral B-protein amyloidosis. Differences and similarities in those cases presenting as a cerebral hemorrhage and those presenting as a dementia of the Alzheimer type. Cerebral hemorrhages with amyloidosis and dementia of the Alzheimer type have many neuropathological findings in common, but there are also marked quantitative and qualitative differences. That makes it highly improbably that the B-protein amyloid depositions itself are the direct cause of extensive neuronal death and dementia in DAT.


Determining the prognosis of childhood epilepsies by establishing immune abnormalities. When seizures develop in a child, an accurate prediction on outcome of the disorder can hardly be given. Literature indicating an association between seizure disorders and Immunoglobulin (Ig) abnormalities, HLA typing and the occurrence of anti-brain antibodies is shortly reviewed. It is argued that by determining such anti-brain antibodies, early ascertainment of prognosis in seizure disorders may be possible.


Follow-up magnetic resonance imaging in Hallervorden-Spatz disease. Bilateral high signal emitting areas in the globus pallidus surrounded by low signal emitting areas have been described as a typical MRI finding in Hallervorden-Spatz disease (HSD). We made a diagnosis of HSD in an 11-year-old girl with progressive dystonia of 4 years duration who showed these typical MRI abnormalities. An initial MRI at the age of 9 was normal. Pathological confirmation of these typical MRI findings has not yet been described, but earlier reports as well as our case suggest that MRI may be helpful in making a clinical diagnosis of HSD. This case further shows that MRI may be normal in an early stage of the disease.


First seizure in adults: to treat or not to treat. A double-blind trial was done in 228 patients with one single seizure 2 weeks before coming to the author. One group was given sodium valproate, the other group placebo. The duration of therapy was 12 months. The results of this trial show that a person with a single seizure has epilepsy and should be treated with sodium valproate.


Operative management of lesions of the axillary nerve, isolated or combined with other nerve lesions. Sixty-six surgically treated lesions of the axillary nerve were reviewed and 57 were followed up over 1 year. Patients were divided into 4 groups: isolated axillary nerve lesions (n = 23), axillary and suprascapular nerve lesions (n = 15), axillary and infraclavicular nerve/plexus lesions (n = 26), and axillary nerve lesions and lower root avulsions (n = 2). Of 34 patients operated upon within 6 months after the trauma, 24 (71%) recovered a force of M4 or M5. Of 17 patients operated upon within 1 year, 10 (59%) had M4 or M5. Of 6 patients operated upon after 1 year, only one had M4. Good shoulder function was only regained when the spinati muscles had recovered good force.


Prevalence of a photoparoxysmal response in the electroencephalograms of epileptics in the three main ethnic groups of Namibia. This descriptive study consists of 1493 EEGs from patients with epilepsy referred to the State Hospital in Windhoek, over the years 1983-1988. Excluded were patients with febrile convulsions, acute symptomatic epilepsy and a history of alcoholism. A standardized procedure of intermittent photic stimulation (IPS) was performed. The three main population groups blacks, coloureds (people of mixed race) and whites, were adequately represented in the sample. Classical photoparoxysmal responses (PPR) occurred in 0.4, 4.2 and 5.2%, respectively. Climatic factors are not considered relevant in the elicitation of a PPR. It is postulated that different mutations occurred in the genes that were involved in the expression of the PPR in epileptic patients of different ethnic groups.


Reflex epilepsy.

Reflex epilepsy. We report 3 cases of reflex epilepsy, 2 of them triggered by reading (reading epilepsy) and one by mathematical calculation (epilepsy arithmetics). Electroencephalographic abnormalities predominated in the dominant hemisphere. The pathophysiologic mechanisms involved in this rare form of epilepsy are commented on, particularly the role played by the association of mental concentration and emotional strain. A possible deficiency in GABA-ergic inhibitory synapses would cause a deficit in cortical inhibition. Different drugs have been used successfully in patients with reflex epilepsy. Psychotherapy relieves anxiety and has been shown to be an effective complement to medical treatment.


Clinical effects and mechanism of action of sumatriptan in migraine. Sumatriptan is a novel, highly effective drug against migraine and cluster headache attacks. It shows a remarkably selective pharmacological profile in animals. Determination of its mechanism of action in human should further the understanding of the pathophysiology of migraine and cluster headache. We, therefore, review current knowledge on the clinical and pharmacological effects of sumatriptan. Important pharmacological actions of sumatriptan are (i) poor penetration of the blood-brain barrier suggesting a peripheral point of action; (ii) 5-HT1-like/5-HT1d receptor-mediated vasoconstriction of large cerebral arteries and dural vessels; and (iii) blockade of neurogenic dural inflammation via 5-HT1d autoreceptor-mediated inhibition of vasoactive neuropeptides within the trigeminovascular system. Future research will tell which mechanism is involved in the pathophysiology of migraine and cluster headache.


Target of brain activity: its own critical point. The brain regulates not only the body and its internal environment and motor activity, but it also regulates the activity of its own very self. What is the set-point or target of the brain's regulation of its own activity? A proposal is that the kind of state known to physics by the name "critical" may give a valuable model of the set-point of the brain's self-regulation. The idea of dynamical scaling then corresponds with John Hughlings Jackson's doctrine of levels. The idea of marginal phase junctions corresponds with the stable lability of the will.


The neurologist as a true philosopher.

The neurologist as a true philosopher. This work is produced in the hope that the neurologist will learn to assert his commanding position (from the nature of his training and the special observations of human beings which his work is constantly providing) of that of the scientific philosopher. At present the discipline of neurology is toward divisive over-specialization, with a loss of that form of broader, even universal, vision of behaviour, of "living", which our professional observations are ever providing. Professor Dr. Bruyn may serve as an admirable model for us to emulate.


Comparison between the Icelandic and Dutch forms of hereditary cerebral amyloid angiopathy. Hereditary cerebral amyloid angiopathy has been described in Icelandic and Dutch families. Although the clinical manifestations show similarities, biochemical characterization revealed that amyloid in the Icelandic patients consists of cystatin C and in the Dutch patients of beta-protein. Both diseases are caused by a single base mutation leading to the same amino acid (viz. glutamine). Furthermore, both cystatin C and the beta-protein precursor are protease inhibitors. Therefore, the mechanism of amyloidogenesis may be similar in both diseases. A comparison of clinical, pathological, genetic, and biochemical aspects of these two types of hereditary cerebral amyloid angiopathy is presented.


Clinico-pathological correlations in Parkinson's disease. Based on comparative clinical and morphometric studies in 45 autopsy cases of Parkinson's disease (PD), 27 clinically presenting with akinesia and rigidity (AR-type), 18 with predominant resting tremor (T-type), the neurobiological basis of the major clinical subtypes in PD is discussed. The AR-type showed higher neuronal losses in locus coeruleus (LC) and in medial and lateral parts of substantia nigra (SNM, SNL), suggesting lesion patterns different from the T-type. More severe cell loss in the serotonergic dorsal raphe nucleus was observed in PD patients with depression than in non-depressed ones. Demented PD subjects showed higher cell loss in SNM than non-demented ones indicating dysfunction of the mesocortical dopamine system, and significantly more severe Alzheimer lesions in isocortex and hippocampus. These and other recent data from the literature indicate that some major clinical features of PD are related to lesions of distinct neuronal systems.


Medical therapy in spinal muscular atrophy: a realistic expectation? The hereditary spinal muscular atrophies (SMA) type I-III belong to those diseases for which even the thought of medical therapy seems forbidden. Two neurotrophic factors are, however, now known to exert a markedly stimulating effect on survival of motor neurons in vivo! In principle such factors may become available by recombinant DNA techniques for experiments in animal models of SMA and if these experiments are successful for clinical trials in man. Medical therapy in SMA should aim primarily at patients early in the rapidly progressive phase of their disease, before massive loss of motoneuron has taken place.


Mechanisms of neuronal loss in Parkinson's disease: a neuroanatomical-biochemical perspective. It is shown that the specific inter- and subregional patterns of striatal dopamine loss in idiopathic Parkinson's disease can serve as a criterion for the evaluation of neurotoxic processes suggested to play an etiological role in this disorder. Based on this premise, the possibility is examined that dopamine-based free radicals (oxidative stress), or a MPTP-like mechanism may be the primary cause of the substantia nigra cell death in idiopathic Parkinson's disease. It is concluded that the most likely determinant of the specific patterns of nigral cell loss and striatal dopamine deficit might be the peculiar topomorphological arrangement of the melanin-containing neurones in the human substantia nigra.


"It ain't necessarily so".

"It ain't necessarily so". Preconceived ideas of the effects of brain damage on mental function may lead to erroneous advice, as illustrated by a case in whom severe traumatic damage of the frontal lobe necessitated a significant professional and social change, but did not result in the absolute behavioral incompetence that would have been predicted by current notions of frontal lobe function. Which mental functions are impaired is a question that cannot be answered by referral to the anatomical pathology, however precise the latter information may be.


Long-term sleep deprivation as a game. The wear and tear of wakefulness. We report here the first sleep deprivation study done on a group of 5 healthy students (1 female, 4 males, 23-24 years of age) while playing a game (Triviant). In 2 persons an EEG was recorded for 6 consecutive 24 h periods with an ambulatory monitor from the baseline night until 72 h after deprivation. The baseline night showed normal hypnograms. The students were deprived of sleep for 65 h following the baseline night. Sleep deprivation was complete and resulted in bradyphrenia, loss of memory and contact with reality, ataxia, decrease in body temperature and loss of body weight. The main sign of recuperation was a strongly increased slow-wave sleep synchronization during the first recuperation period (day-time sleep) only. There were no signs of REM rebound.


Characterization of the absorption phase of marijuana smoking. Rapid blood collection, a paced smoking protocol and timely collection of physiologic and behavioral measures were used to characterize the absorption phase of marijuana smoking. Six healthy males smoked a single marijuana cigarette (placebo, 1.75%, or 3.55% delta-9-tetrahydrocannabinol) in a double-blind, randomized, Latin square study design. Rapid blood sampling with a continuous withdrawal pump allowed simultaneous collection with concurrent physiologic and behavioral measures. Mean plasma levels of 7.0 and 18.1 ng/ml delta-9-tetrahydrocannabinol were observed after the first inhalation of a 1.75% and 3.55% delta-9-tetrahydrocannabinol cigarette, respectively. Blood levels increased rapidly and peaked at 9 minutes, before initiation of the last puff sequence at 9.8 minutes. Three of six subjects reported increases in drug "liking" scores after the first puff, and all subjects responded by the second puff of a high dose cigarette. Significant increases in heart rate and diastolic blood pressure occurred shortly after peak blood levels. Previous studies have indicated that there is a substantial time delay between peak plasma levels of delta-9-tetrahydrocannabinol and drug-induced effects. This study showed that behavioral and physiologic effects appear concurrently or within minutes after the rapid appearance of delta-9-tetrahydrocannabinol in blood during marijuana smoking.


High-voltage pulsed galvanic stimulation: effects of frequency of current on blood flow in the human calf muscle. 1. Twelve healthy subjects received high-voltage pulsed galvanic stimulation (115-475 V d.c.) delivered in separate treatments of 2, 32 and 128 pulses/s for 10 min at the subject's maximum tolerable voltage while calf muscle blood flow was measured by non-invasive Whitney strain-gauge venous occlusion plethysmography. 2. The high-voltage pulsed galvanic stimulation was administered with negative polarity by an intermittent mode of 30 s on, 30 s off. Measurements of calf muscle blood flow were made during each 30 s period when the stimulus was off. The effect of one 30 s maximum isometric contraction of the calf muscles on blood flow was used as a standard for evaluating the effectiveness of high-voltage pulsed galvanic stimulation on calf muscle blood flow. 3. Significant (paired t-tests; P less than 0.05) increases in calf muscle blood flow over the preceding baseline levels occurred for the isometric contraction (322%) and for frequencies of 2 pulses/s (33.5%) and 128 pulses/s (13.36%), but not for a frequency of 32 pulses at which calf muscle blood flow increased in only six of 12 subjects. The mean increases in calf muscle blood flow at 2 and 128 pulses/s represented 11.63% and 4.0%, respectively, of that resulting from the isometric contraction. 4. A clear positive correlation between voltage level and the magnitude of increase in calf muscle blood flow was demonstrated but differed for each frequency used.(ABSTRACT TRUNCATED AT 250 WORDS)


Cutaneous blood flow during a hypoglycaemic clamp in insulin-dependent diabetic patients and healthy subjects. 1. A marked cutaneous vasodilatation has been shown to occur in healthy subjects, but not in insulin-dependent diabetic patients, in response to hypoglycaemia induced by a rapid intravenous bolus injection of insulin. 2. In the present study cutaneous blood flow in response to a gradual decline in blood glucose concentration was investigated in eight young adult diabetic patients and in eight age- and sex-matched control subjects. After a hyperinsulinaemic euglycaemic clamp for 40 min, hypoglycaemia was induced (plasma glucose concentration 2 mmol/l) by a standardized stepwise reduction in the intravenous glucose infusion. 3. Blood flow was measured by using a laser Doppler sensor and a cutaneous O2 electrode placed on the medial aspect of the forearm, and a laser Doppler sensor placed on the forehead. 4. No significant change in cutaneous blood flow occurred during euglycaemic hyperinsulinaemia. 5. In control subjects a marked increase in blood flow during hypoglycaemia was observed in the forearm by both methods. No corresponding change was observed in the forehead. 6. In the diabetic patients the increase in cutaneous blood flow was absent in both the forearm and forehead. 7. It is concluded that hypoglycaemia, but not hyperinsulinaemia, is associated with a regional cutaneous vasodilatation in healthy control subjects. This cutaneous vasodilatation is absent in diabetic patients.


Clearance of brain natriuretic peptide in patients with chronic heart failure: indirect evidence for a neutral endopeptidase mechanism but against an atrial natriuretic peptide clearance receptor mechanism. 1. Brain natriuretic peptide is a new natriuretic hormone with striking similarity to atrial natriuretic peptide, but there are no previous data concerning its clearance in man. Two pathways of clearance for atrial natriuretic peptide are recognized: degradation by neutral endopeptidase and binding to atrial natriuretic peptide clearance receptors. We have examined the effect of candoxatril, an inhibitor of neutral endopeptidase (dose range 10-200 mg), and the effect of an infusion of a pharmacological dose [45 micrograms (90 micrograms in two patients)] of synthetic human atrial natriuretic peptide on plasma human brain natriuretic peptide-like immunoreactivity levels in seven patients with mild to moderate chronic heart failure. 2. Plasma human brain natriuretic peptide-like immunoreactivity levels were elevated in all patients (mean +/- SEM 22.0 +/- 6.2 pmol/l) compared with healthy control subjects (1.3 +/- 0.2 pmol/l, n = 11). 3. In all patients, candoxatril increased both plasma atrial natriuretic peptide (P less than 0.05) and plasma human brain natriuretic peptide-like immunoreactivity (P less than 0.05) levels. 4. By contrast, an exogenous infusion of atrial natriuretic peptide had no effect on plasma human brain natriuretic peptide-like immunoreactivity levels despite increasing the plasma atrial natriuretic peptide concentration to 424 +/- 74 pmol/l, which is a level of atrial natriuretic peptide which would have 'swamped' all atrial natriuretic peptide clearance receptors. 5. We have therefore shown that plasma human brain natriuretic peptide-like immunoreactivity levels in chronic heart failure are increased by a neutral endopeptidase inhibitor, but are unchanged by an exogenous infusion of atrial natriuretic peptide.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of the Fab fragment of digoxin antibody on the natriuresis and increase in blood pressure induced by intracerebroventricular infusion of hypertonic saline solution in rats. 1. The effects of intravenous injection of Fab fragments of anti-digoxin IgG (Digibind) on the changes in blood pressure, urine volume and urinary sodium excretion after intracerebroventricular infusion of artificial cerebrospinal fluid with normal or high sodium concentration were examined in anaesthetized rats. 2. The biological efficacy of Digibind was confirmed by experiments in vitro and in vivo, which showed that pretreatment with Digibind completely abolished or significantly attenuated the aortic contractile response or pressor response to digoxin in guinea-pigs. 3. Infusion of high-sodium cerebrospinal fluid, but not normal-sodium cerebrospinal fluid, into the lateral brain ventricle of rats caused marked increases in blood pressure, urine volume and urinary sodium excretion. 4. Digibind did not significantly affect the increases in blood pressure, urine volume and urinary sodium excretion caused by intracerebroventricular infusion of high-sodium cerebrospinal fluid. 5. Digoxin-like immunoreactive factor may play a minor role, if any, in central nervous system-induced natriuresis in rats.


Increases in NO2-/NO3- excretion in the urine as an indicator of the release of endothelium-derived relaxing factor during elevation of blood pressure. 1. Under hormonally constant conditions, the effects of a sudden increase in blood pressure on the release of endothelium-derived relaxing factor were evaluated by measuring urinary excretion of NO2-/NO3- in rats with renal denervation. 2. Elevation of blood pressure from 136 +/- 2 to 153 +/- 3 mmHg by an aortic clamp below the renal arteries induced a significant increase in urinary excretion of NO2-/NO3- from 76.6 +/- 4.2 x 10(2) to 108.1 +/- 8.3 x 10(2) pmol min-1 g-1 kidney weight (P less than 0.05). 3. Infusion of NG-monomethyl-L-arginine (1 mg min-1 kg-1) without an aortic clamp raised mean blood pressure to a similar level; however, urinary excretion of NO2-/NO3- was decreased significantly. 4. During infusion of NG-monomethyl-L-arginine, aortic occlusion caused a significant increase in blood pressure without any changes in NO2-/NO3- excretion in the urine. 5. These results suggest that the formation of NO, an indicator of endothelium-derived relaxing factor release, was increased by mechanical pressure elevation without apparent changes in hormonal and neural factors.


Lithium clearance in dogs: effects of water loading, amiloride and lithium dosage. 1. The influences of lithium dosage, urine flow rate and acute administration of amiloride on the renal handling of lithium in normal conscious dogs were investigated. 2. Lithium was administered in the diet at daily doses of 100 mg or 2 mg of lithium carbonate for the 2 days preceding the investigation. Urine flow rate was altered by water loading with and without arginine vasopressin infusion (5 pg min-1 kg-1). Amiloride was administered as an intravenous bolus (130 micrograms/kg) followed by a continuous infusion (1.22 micrograms h-1 kg-1). 3. Glomerular filtration rate (exogenous creatinine clearance) did not change within series and was not different between series; it averaged 3.27 ml min-1 kg-1. Control levels of fractional lithium excretion (12.4 +/- 1.2%, mean +/- SEM) were not influenced by hydration, hydration plus arginine vasopressin administration or the lithium dosage. However, in hydrated dogs having a plasma lithium concentration of 130-140 mumol/l, amiloride administration was associated with a 5% increase in fractional lithium excretion (P less than or equal to 0.01). 4. It is concluded that distal tubular lithium reabsorption may take place in sodium-replete conscious dogs undergoing water diuresis. The low fractional lithium excretion even during amiloride infusion (14.1-16.8%) may well be due to a high fractional reabsorption of lithium in the proximal tubules; however, a significant reabsorption of lithium distal to the proximal straight tubules by amiloride-insensitive pathways cannot be excluded.


Effects of cyclosporin A on glomerular barrier function in the nephrotic syndrome. 1. To elucidate the mechanisms by which cyclosporin A diminishes proteinuria, we studied 20 patients with severe nephrotic syndrome. Biopsy-established pathologies included minimal change disease (n = 5), membranous glomerulopathy (n = 6), membranoproliferative glomerulonephritis (n = 5) and focal segmental glomerulosclerosis (n = 4). Before, at the end of a 90 day course of cyclosporin A, and finally 1 month after stopping cyclosporin A we determined 24 h protein excretion. Measurements of glomerular filtration rate, effective renal plasma flow, fractional clearance rates of albumin and immunoglobulins with different charges and the transglomerular sieving of uncharged dextrans of broad size distribution were used to study the effects of cyclosporin A on renal perfusion and the glomerular filtration barrier. The findings were analysed with a theoretical model of solute transport. 2. Among the different forms of glomerulopathy the response to low-dose cyclosporin A (trough levels 32.0-36.9 ng/ml) varied markedly. In minimal change disease, proteinuria decreased from 9.5 +/- 3.1 to 1.3 +/- 0.2 g/24 h (mean +/- SEM, P less than 0.01). This response was due to restoration of the charge selectivity of the glomerular barrier. The depressed value of the glomerular permeability coefficient also returned to normal. Glomerular filtration rate, effective renal plasma flow and renal vascular resistance did not change. Proteinuria returned after stopping cyclosporin A, although it did not reach pretreatment levels. In membranous glomerulopathy, proteinuria fell from 9.9 +/- 1.5 to 1.8 +/- 0.3 g/24 h (P less than 0.01). Changes in protein excretion and dextran sieving were compatible with an increase in glomerular permselectivity and a decrease in filtrate flow through the 'shunt' pathway. Glomerular filtration rate was maintained, although effective renal plasma flow fell significantly. Proteinuria relapsed after stopping cyclosporin A. In membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis proteinuria did not respond to cyclosporin A, although cyclosporin A exerted important haemodynamic effects. 3. In minimal change disease and membranous glomerulopathy cyclosporin A exerts its beneficial effects on proteinuria through changes in the properties of the glomerular barrier, resulting in increased charge and size selectivity, respectively.


Platelet cytosolic free calcium concentration and parathyroid hormone: changing relationships with haemodialysis in end-stage renal disease. 1. Twelve patients receiving haemodialysis for end-stage renal failure were studied at a single dialysis session. Platelet cytosolic calcium concentration, plasma ionized calcium concentration and serum parathyroid hormone concentration were measured before dialysis, mid-dialysis and 30 min after dialysis. 2. Plasma ionized calcium concentration increased towards dialysate calcium concentrations, falling insignificantly after cessation of dialysis. Serum parathyroid hormone concentration fell by 39% during dialysis, with incomplete recovery afterwards. There was no overall change in platelet cytosolic calcium concentration. 3. Patients were divided into two subgroups: low parathyroid hormone (serum parathyroid hormone concentration less than 10 pmol/l) and high parathyroid hormone (serum parathyroid hormone concentration greater than 10 pmol/l). Before dialysis, values of platelet cytosolic calcium concentration or plasma ionized calcium concentration were not statistically different between the subgroups, but the platelet cytosolic calcium concentration was higher in the high-parathyroid hormone subgroup during and after dialysis. 4. Before haemodialysis there was a linear correlation between plasma ionized calcium concentration and platelet cytosolic calcium concentration, which disappeared during dialysis. In contrast, there was no relationship between serum parathyroid hormone concentration and platelet cytosolic calcium concentration before dialysis, but after dialysis a hyperbolic relationship was evident. 5. These results suggest that uraemic toxins may interfere with cytosolic calcium homoeostasis, allowing passive diffusion of extracellular calcium to influence the resting concentration, and that this effect is reversible by haemodialysis.


Isolation of an ultrafilterable Ca(2+)-ATPase inhibitor from the plasma of uraemic patients. 1. Calcium concentration and Ca(2+)-ATPase activity under basal conditions and after maximal stimulation with calmodulin were measured in erythrocytes from 32 patients with end-stage renal failure on haemodialysis and from 27 healthy subjects. 2. In patients with renal failure the Ca2+ concentration in erythrocytes was elevated compared with healthy subjects (4.27 +/- 1.02 versus 2.86 +/- 0.57 mumol/l, P less than 0.05). 3. Basal Ca(2+)-ATPase activity was lower in the patients with renal failure than in healthy subjects (4.62 +/- 1.34 versus 5.43 +/- 1.23 pmol of phosphate min-1 10(-6) erythrocytes). After maximal stimulation, Ca(2+)-ATPase activity reached 6.93 +/- 2.81 pmol of phosphate min-1 10(-6) erythrocytes in the patients with renal failure, whereas in healthy subjects stimulation yielded a Ca(2+)-ATPase activity of 32.54 +/- 8.48 pmol of phosphate min-1 10(-6) erythrocytes. 4. Incubation of erythrocytes from healthy subjects with plasma from uraemic patients caused inhibition of Ca(2+)-ATPase. Likewise, the ultrafiltrate from plasma obtained by haemofiltration treatment inhibited Ca(2+)-ATPase. 5. Gel chromatography of the ultrafiltrate and laser desorption/ionization mass spectroscopy revealed that a fraction containing substances with a molecular mass of about 300 Da inhibited Ca(2+)-ATPase. 6. It is concluded that, in uraemia, a Ca(2+)-ATPase inhibitor accumulates in the plasma, and this could contribute to the toxicity of uraemia by inhibiting cellular Ca2+ transport in erythrocytes and possibly other tissues.


Ion transport characteristics of the murine trachea and caecum. 1. The basic defect in cystic fibrosis relates to abnormalities of ion transport in affected tissues, such as the respiratory and gastrointestinal tracts. The identification of the cystic fibrosis gene has enabled studies on the production of a cystic fibrosis transgenic mouse to be undertaken. Knowledge of normal ion transport will be necessary for the validation of any such animal model. We have therefore characterized selected responses of the murine trachea and caecum mounted in 'mini' Ussing chambers under open-circuit conditions. 2. Basal values for the trachea were: potential difference, 1.1 mV (SEM 0.2; n = 18); equivalent short-circuit current, 20.4 microA/cm2 (3.6); conductance, 18.2 mS/cm2 (1.7). Corresponding values for the caecum were: potential difference, 0.7 mV (0.1; n = 18); equivalent short-circuit current, 11.0 microA/cm2 (1.6); conductance, 14.5 mS/cm2 (1.4). 3. Amiloride (10 mumol/l) produced a significant (P less than 0.001) fall in potential difference of 43.0% (5.7) in the trachea, but had no significant effect in the caecum. 4. Subsequently, one of three protocols was used to assess the capacity of either tissue for chloride secretion. Addition of a combination of forskolin (1 mumol/l) and zardaverine (10 mumol/l) produced rises in the potential difference of 873% (509) in the trachea and 399% (202) in the caecum. Both A23187 (10 mumol/l) and phorbol dibutyrate (10 nmol/l) increased tracheal potential difference by 350% (182) and 147% (47), respectively. Neither had a significant effect in the caecum. 5. Subsequent addition of bumetanide caused a fall in the stimulated potential difference of between 39.8% and 71.7%, depending on secretagogue and tissue type.(ABSTRACT TRUNCATED AT 250 WORDS)


Regional differences in the response to platelet-activating factor in rabbit colon. 1. Platelet-activating factor is an inflammatory mediator related to eicosanoids which is known to stimulate anion secretion in the distal colon. Since there are regional differences in ion transport within the colon, the influence of platelet-activating factors on ion transport and epithelial permeability has been studied in rabbit caecum and distal colon mounted in Ussing chambers. 2. The effect of platelet-activating factor (1-50 nmol/l) on net electrogenic ion transport was to stimulate a biphasic increase in short-circuit current in the distal colon but not in the caecum. The platelet-activating factor-induced rise in short-circuit current was shown by ion replacement and pharmacological inhibitor studies to be consistent with chloride and bicarbonate secretion in the early phase, but with chloride secretion alone in the later phase. The effect on ion transport was specific and reversible and was enhanced by 0.25% BSA. 3. Colonic permeability, assessed by transmucosal resistance and mannitol flux, was increased by platelet-activating factor in both the distal colon and the caecum. This was consistent with an effect on platelet-activating factor on the paracellular pathway, because resistance decreased even when transcellular chloride transport was inhibited by frusemide or ion replacement. A specific platelet-activating factor antagonist (U66985) inhibited the effects of platelet-activating factor in both the distal colon and the caecum. 4. The results show that platelet-activating factor stimulates anion secretion only in the distal colon, but increases permeability in both the caecum and the distal colon.


Pernicious anaemia as a risk factor for osteoporosis. 1. If gastric acid is necessary for the absorption of dietary calcium, the total absence of gastric acid secretion that occurs in pernicious anaemia could result in bone loss. To investigate this, we measured calcium absorption and bone density in 21 postmenopausal women (ages 51-76 years) with pernicious anaemia and in 24 normal postmenopausal women (ages 51-79 years). 2. Relative to the normal women, in the women with pernicious anaemia the bone mineral density of the lumbar spine was decreased by 16% (P less than 0.001). 3. After adjustment for age and body weight, lumbar spine bone mineral density correlated with the serum concentration of group 1 pepsinogens (a group of proteins produced by the gastric fundus) (r = 0.61, P less than 0.01). 4. Despite achlorhydria, the women with pernicious anaemia had normal true fractional calcium absorption and normal serum levels of parathyroid hormone and 1,25-dihydroxyvitamin D. 5. We conclude that gastric acid is not required for the absorption of dietary calcium. Thus, the loss of cancellous bone must be caused by some mechanism yet to be identified.


Four-component model for the assessment of body composition in humans: comparison with alternative methods, and evaluation of the density and hydration of fat-free mass. 1. Body composition was assessed in 28 healthy subjects (body mass index 20-28 kg/m2) by dual-energy X-ray absorptiometry, deuterium dilution, densitometry, 40K counting and four prediction methods (skinfold thickness, bioelectrical impedance, near-i.r. interactance and body mass index). Three- and four-component models of body composition were constructed from combinations of the reference methods. The results of all methods were compared. Precision was evaluated by analysis of propagation of errors. The density and hydration fraction of the fat-free mass were determined. 2. From the precision of the basic measurements, the propagation of errors for the estimation of fat (+/- SD) by the four-component model was found to be +/- 0.54 kg, by the three-component model, +/- 0.49 kg, by deuterium dilution, +/- 0.62 kg, and by densitometry, +/- 0.78 kg. Precision for the measurement of the density and hydration fraction of fat-free mass was +/- 0.0020 kg/l and +/- 0.0066, respectively. 3. The agreement between reference methods was generally better than between reference and alternative methods. Dual-energy X-ray absorptiometry predicted three- and four-component model body composition slightly less well than densitometry or deuterium dilution (both of which greatly influence these multi-component models). 4. The hydration fraction of fat-free mass was calculated to be 0.7382 +/- 0.0213 (range 0.6941-0.7837) and the density of fat-free mass was 1.1015 +/- 0.0073 kg/l (range 1.0795-1.1110 kg/l), with no significant difference between men and women for either. 5. The results suggest that the three- and four-component models are not compromised by errors arising from individual techniques.(ABSTRACT TRUNCATED AT 250 WORDS)


Polyunsaturated fatty acids suppress human peripheral blood lymphocyte proliferation and interleukin-2 production. 1. The effects of a variety of fatty acids on human peripheral blood lymphocyte proliferation stimulated by concanavalin A or purified protein derivative of Mycobacterium tuberculosis were studied. 2. The proliferative response to concanavalin A was inhibited by all of the polyunsaturated fatty acids tested (eicosapentaenoate, arachidonate, docosahexaenoate, linoleate and alpha-linolenate) and also by the saturated fatty acid, stearate. The greatest inhibition of proliferation (approximately 85%) was caused by eicosapentaenoate. 3. The proliferative response to the purified protein derivative of Mycobacterium tuberculosis was inhibited by all of the polyunsaturated fatty acids tested, except alpha-linolenate, and also by stearate. The greatest inhibition of proliferation (approximately 75%) was caused by eicosapentaenoate. 4. The pattern of inhibition of proliferation by fatty acids was similar to that previously reported for rat lymphocytes with one exception: oleate did not inhibit human lymphocyte proliferation. 5. The proliferation of T-lymphocytes is dependent upon their ability to synthesize and secrete the cytokine, interleukin-2. In the presence of mitogen the concentration of interleukin-2 in the culture medium increased markedly above that in the medium of non-stimulated cells. 6. All polyunsaturated fatty acids tested caused a decrease in the concentration of interleukin-2; the greatest decrease (approximately 90%) was caused by eicosapentaenoate. 7. There was a good correlation between lymphocyte proliferation in the presence of fatty acids and interleukin-2 concentration. However, stearate did not decrease the interleukin-2 concentration but did inhibit lymphocyte proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of simvastatin on plasma lipid and lipoprotein concentrations and low-density lipoprotein metabolism in the nephrotic syndrome. 1. The effect of inhibiting the rate-limiting enzyme (3-hydroxy-3-methylglutaryl-CoA reductase, EC 1.1.1.88) in cholesterol synthesis on plasma lipid and lipoprotein concentrations was investigated in 16 patients with primary glomerular disease, heavy proteinuria, well-preserved renal function and hypercholesterolaemia. 2. Detailed studies of low-density lipoprotein metabolism were performed on eight patients before and after 12 weeks of simvastatin therapy. Radioiodinated tracers were used to quantify the fractional catabolic rate of low-density lipoprotein by apolipoprotein B/E receptors and alternative pathways. 3. Simvastatin produced consistent reductions in total plasma cholesterol concentration (median 36.9%), plasma low-density lipoprotein-cholesterol concentration (43.6%) and apolipoprotein B pool size (29.9%). 4. In contrast, the changes in kinetic parameters of low-density lipoprotein metabolism showed no clear pattern. Although an increase in the receptor-mediated catabolism of low-density lipoprotein was demonstrated in five patients, no change or a slight decrease was seen in three patients. Production rates were not significantly altered, although there was a slight decrease in the median value (from 12.4 to 9.7 mg day-1 kg-1). Plasma lathosterol concentration was reduced in all eight patients (range 34-71%), indirectly confirming significant inhibition of cholesterol synthesis. 5. These results suggest that, as in patients with primary moderate hyperlipidaemia, the significant cholesterol-lowering effect of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors in the nephrotic syndrome is accompanied by variable changes in lipoprotein metabolism. The reasons for this heterogeneous response are unclear. This reflects our limited understanding of the metabolic basis of nephrotic hyperlipidaemia and the relationship between hepatic sterol synthesis and plasma lipoprotein kinetics.


Relationship between spontaneous dyspnoea and lability of airway obstruction in asthma. 1. As marked lability of bronchial obstruction is a risk factor for asthma severity, it may influence dyspnoea, the most common subjective complaint in asthma. We therefore studied the relationship between spontaneous dyspnoea and the degree of bronchial lability, as assessed by the daily variability in peak expiratory flow rate and the bronchial responsiveness to either carbachol or salbutamol, in 33 stable symptomatic asthmatic patients. 2. Three times daily, for 10 consecutive days, the patients rated the intensity of their dyspnoea on a visual analogue scale and immediately afterwards recorded their peak expiratory flow rate. Within the next 5 days, we determined the bronchial response by measuring the forced expiratory volume in 1 s and the specific resistance of airways to either carbachol or salbutamol according to baseline airway obstruction. 3. We characterized dyspnoea for each patient by using two parameters: (1) the relationship with underlying airway obstruction, as assessed by the correlation coefficient r between dyspnoea scores and corresponding values of peak expiratory flow rate (r DSc-PEFR), and (2) the intensity, as assessed by the mean visual analogue scale dyspnoea score adjusted for comparable airway obstruction. Bronchial lability was characterized by (1) variability in mean daily peak expiratory flow rate and (2) bronchial responsiveness to either carbachol (as assessed by the threshold dose and the slope of the dose-response curve) or salbutamol (as assessed by the threshold dose and maximal response). We assessed the relationship between dyspnoea and bronchial lability by correlating each of their respective characteristics. 4. We found large inter-subject differences in both characteristics of dyspnoea.(ABSTRACT TRUNCATED AT 250 WORDS)


Long-term follow-up study of cats vaccinated with a temperature-sensitive feline infectious peritonitis vaccine. The long-term safety of a temperature-sensitive feline infectious peritonitis (FIP) vaccine was evaluated. Five hundred eighty-two healthy cats of various age groups were vaccinated with 2 doses of the vaccine. Seventy-eight percent, or 453 cats, were available for follow-up. The mean follow-up period was 541 days. At the end of the follow-up period, 427 cats (94%) were alive. FIP was not diagnosed in any cat during the follow-up period, but 1 cat died of FIP after completion of the follow-up period. Fifty cats (11%) presented with a problem during the follow-up period, but there were typical of those seen in a feline practice. The temperature-sensitive FIP vaccine appears to be safe for use in the general cat population. It does not appear to sensitize cats to develop FIP, nor do there appear to be any other systemic problems associated with use of the vaccine.


Cutoff assignment strategies for enhancing randomized clinical trials. The randomized clinical trial (RCT) is the preferred method for assessing the efficacy of treatments. Recent ethical and logistical criticisms suggest that new variations of the traditional RCT are needed. Some of these criticisms may be addressed with new hybrid designs that combine random assignment with assignment by one or more cutoff values on a baseline variable (e.g., severity of illness). In a simple version of such a "cutoff-based" RTC, persons scoring below a cutoff score on a baseline measure (i.e., the least severely ill) are automatically assigned to the control-treated group, those scoring above a second, higher cutoff (i.e., the most ill) are automatically assigned to the test-treated group, and those scoring in the interval between the cutoff scores (i.e., the moderately ill) are randomly assigned to either group. Depending on the baseline score, the patient is assigned to treatment either randomly or by the need-based, clinically related baseline score. Six cutoff-based design variations are studied via simulations and compared with the traditional RCT and the single-cutoff (i.e., regression-discontinuity) design. All variations yield unbiased estimates of the treatment effect but estimates differ in efficiency, with the RCT being most efficient and the single-cutoff design being least efficient. Secondary analyses of data from the Cross-National Collaborative Study of the Effects of Alprazolam (Xanax) on panic are conducted for each variation by selectivity discarding cases from the original dataset to stimulate cutoff-based assignment. The results confirm the simulations and illustrate how cutoff-based designs might look with real data.


A test for the difference between two treatments in a continuous measure of outcome when there are dropouts. Consider a randomized clinical trial that is designed to compare two treatments in which the treatment continues during the entire period of the study. Some subjects may refuse to complete the protocol and will not return for the final evaluation. Since the reason for dropping out may be related to the subject's self-assessed evaluation of the usefulness of the treatment or to undesirable side effects of the treatment, subjects who drop out cannot be treated as a random sample of those who entered the trial. We consider the situation where the measure of efficacy of the treatment is continuous. Under the assumption that the expected value of the measure for those who drop out is not better (the direction depends on the measure) than that for those who complete the study, we propose an adjustment to the usual test for a difference between treatments that allows for the inclusion of the probable effect of the dropouts; this provides a bound on the test for efficacy of the treatment. First, we estimate a predetermined percentile, such as the median score, of the control, or placebo, group and assign this score to all those who dropped out from both groups and to all subjects in both groups with scores that are worse than the assigned score. A Mann-Whitney statistic is then used to test the equality of the distributions of the two groups. We show by simulation that this modified test is equivalent to a test using the complete data and has greater power than that obtained when including the dropouts by assigning the worst observed score to them. This test will be less sensitive to bias that is induced by exclusion of dropouts from the final evaluation.


Analysis of randomized and nonrandomized patients in clinical trials using the comprehensive cohort follow-up study design. In clinical research, randomized trials are widely accepted as the definitive method of evaluating the efficacy of therapies. The random assignment of patients to their treatment ensures the internal validity of the comparison of new treatments with controls. An assessment of the external validity of trial results can best be achieved by comparing the study population to the population of patients who met the eligibility criteria but did not consent to randomization. A part of the data of the Coronary Artery Surgery Study (CASS), in which coronary artery bypass surgery is compared to conventional medical therapy in patients with coronary artery disease, is used to illustrate a strategy of multivariate analysis of randomized and nonrandomized patients which allows an investigation of both internal and external validity. The method used Cox's proportional hazards regression model with inclusion of covariates for randomization status and corresponding interactions in addition to the usual covariates for treatment and the important prognostic factors.


The impact of automated blood pressure devices on the efficiency of clinical trials. By reducing measurement error, automated blood pressure (BP) devices should enhance the precision of BP estimation and thereby decrease sample size requirements in clinical trials of BP-lowering therapy. Enhanced precision would be particularly relevant to clinical trials assessing the efficacy of nonpharmacological therapies. In the present investigation, resting (clinic) BPs by the Dinamap 8100 (a stationary device) and the Accutracker II (an ambulatory device) were as precise as manual BPs given an equal number of observations by each method. However, both the Dinamap and Accutracker devices underestimated resting diastolic BP in comparison to the manual observers. Estimates of average daytime and 24-hour ambulatory BP, based on large numbers of observations over an extended period of time, were extremely precise. These findings suggest that the use of automated devices to measure resting BP may not reduce samples sizes, whereas use of ambulatory BP devices should reduce samples sizes considerably.