Characterization of cell-surface beta-adrenergic ([3H]CGP-12177) binding in adult rat ventricular myocytes: lack of regulation by beta-agonists at physiological concentrations. The major focus of this paper is the characterization and quantification of rat cardiomyocyte, cell-surface beta-adrenergic receptors labelled with the hydrophilic radioligand [3H]CGP-12177. The ventricular cardiomyocytes used in these experiments have previously been extensively studied in our laboratory and confirmed to be functionally compatible with similar cells in vivo. Specific binding of [3H]CGP was stereospecific, saturable and of high affinity. Binding of [3H]CGP was also readily reversible, demonstrated appropriate drug specificity and positively correlated with increasing cell concentrations. The potency of the beta 1-antagonist atenolol was almost 100 times higher than that of the beta 2-antagonist ICI-118.551 in binding to the [3H]CGP binding site. This preparation appears ideal for the investigation of beta-adrenergic receptor regulation in heart cells. Indeed, our initial experiments show clearly that pharmacological concentrations of isoproterenol, and norepinephrine, can reduce (down-regulate) the number of specific [3H]CGP binding sites. This result is in agreement with many other reports on similar experiments in a variety of cell types. However, physiologically relevant concentrations of these two agonists (1-100 nM) do not induce down-regulation of the beta-adrenergic receptors in short-term (2 h) incubations. Nevertheless, the high-affinity receptors that we have described mediate a contractile response to isoproterenol in the nanomolar concentration range (EC50 = 3.6 +/- 0.3 nM). This is approximately 300 times lower than the concentration needed to produce down-regulation. Thus, our data indicate that short-term down-regulation of cardiomyocyte beta-adrenergic receptors can only be observed with high, pharmacological concentrations of isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)


Phylogenetic relationships of the thylacine (Mammalia: Thylacinidae) among dasyuroid marsupials: evidence from cytochrome b DNA sequences. DNA sequences from the mitochondrial cytochrome b gene were obtained from a museum specimen of the presumed extinct thylacine (Thylacinus cynocephalus) and were compared with homologous sequences from 13 representatives of the Australian marsupial family Dasyuridae. The relationship of the thylacine to dasyurids has been suggested by previous anatomical and molecular studies, but its position within the dasyuroid radiation has not been addressed with genetic data. Phylogenetic analysis of the sequences reported here suggests that the thylacine is a sister group to Dasyuridae and lends support to the hypothesis that Thylacinus represents an ancient Australian marsupial lineage. Relationships with Dasyuridae support the results of other recent molecular studies, particularly in showing the affinities of endemic New Guinean subfamilies with larger Australian clades.


[Cryptorchidism].

[Cryptorchidism]. Cryptorchidism is a frequent abnormality which affects approximately 1% of children at age 1 year. Many nonscrotal testes are retractile and require no therapy. The pathogenesis remains controversial and involves possible mechanical, dysgenetic or hormonal factors. The latter are consistent with a partial defect in the hypothalamo-pituitary-gonadal axis, which may cause progressive histologic alterations in the testes after the first 6 months of life. Ultrasound is the simplest diagnostic technique (after clinical examination) to identify the testes in the inguinal region, while Magnetic Resonance Imaging can be performed to visualize abdominal testes. Therapy is still a matter of controversy. Hormonal treatments with HCG, LHRH or both should be used as first-intention treatment and their efficacy ranges from 0% to 60% in the various studies. LHRH nasal spray seems less effective if used alone. An early surgical treatment is recommended if the gonad is in the abdomen or close to the internal inguinal ring. The risk of cancer is increased in subjects with a history of cryptorchidism and even includes the contralateral descended testes. Early orchidopexy is not associated with a certain decrease of the risk. Cancer can be prevented by searching for in situ carcinoma with a biopsy performed after puberty. Fertility is impaired mainly in men with a history of bilateral cryptorchidism. There is weak evidence that early orchidopexy may improve fertility rates.


Mechanical filtering of sound in the inner ear. We have studied the distortion generated by the cochlea to gain insight into the mechanisms responsible for the sharp tuning or 'frequency selectivity' of the inner ear. We used two stimulating tones of moderate intensity which are progressively separated in frequency, and measured the ear canal cubic distortion components which are generated as a consequence of the stimulus interaction in the cochlea. We inferred that the distortion is generated from the frequency region of the higher of the two stimulus tones and that it is then band-pass filtered by a structure which is tuned to a frequency just over half an octave below that of the high-frequency tone. We suggest that the structure responsible for this band-pass filtering is the tectorial membrane, and we conclude that our results support theories of cochlear mechanics in which resonances due to the tectorial membrane interact with those of the basilar membrane to enhance the frequency selectivity of the inner ear.


Activation of L-type Ca2+ currents in cardiac myocytes by photoreleased GTP. L-type calcium currents (ICa) were recorded from isolated ventricular myocytes by using standard patch-clamp methods. In the absence of agonist, photorelease of GTP by flash photolysis of intracellularly applied caged-GTP rapidly increased the amplitude of ICa over a wide range of membrane potentials. Control experiments clearly demonstrated that this effect was not due to either the release of photolytic by-products or to the light flash itself. The timecourse for activation of ICa by photolysis of caged-GTP was markedly altered by intracellular application of either GDP beta S or GTP gamma S. Upon maximal stimulation of ICa by intracellular dialysis with cAMP, photoreleased GTP induced a small, rapid increase in ICa followed by a gradual inhibition. The presence of Rp-cAMPS intracellularly reduced both the magnitude of the response to photoreleased GTP and its time to peak. Similar effects were observed when protein kinase inhibitor dialysed the cell interior, suggesting that both cAMP-dependent and independent processes were involved in this effect. We conclude that rapid release of GTP within ventricular myocytes, in the absence of agonist, causes rapid activation of L-type Ca2+ current. Mechanisms underlying this effect include stimulation of adenylate cyclase, together with other, as yet uncharacterized, GTP-dependent pathways for increasing ICa in the heart.


A latitudinal cline in a Drosophila clock gene. The clock gene period determines biological rhythmicity in Drosophila melanogaster and encodes a protein characterized by an alternating series of threonine-glycine pairs. The minisatellite region encoding the threonine-glycine repeat is polymorphic in length in natural Drosophila melanogaster populations. In this paper we report the geographical analysis of this polymorphism within Europe and North Africa. A robust clinal pattern is observed along a north-south axis. We suggest the possibility that the length polymorphism could be maintained by thermal selection because the threonine-glycine region has been shown to provide thermostability to the circadian phenotype.


Role of the phosphoenolpyruvate-dependent fructose phosphotransferase system in the utilization of mannose by Escherichia coli. Mutants of Escherichia coli devoid of the membrane-spanning proteins PtsG and PtsMP, which are components of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) and which normally effect the transport into the cells of glucose and mannose, do not grow upon or take up either sugar. Pseudorevertants are described that take up, and grow upon, mannose at rates strongly dependent on the mannose concentration in the medium (apparent Km > 5 mM); such mutants do not grow upon glucose but are derepressed for the components of the fructose operon. Evidence is presented that mannose is now taken up via the fructose-PTS to form mannose 6-phosphate, which is further utilized for growth via fructose 6-phosphate and fructose 1,6-bisphosphate.


Structural and functional evidence for activation of a chick retinoid X receptor by eicosanoids. The retinoid X receptors (RXR-alpha, RXR-beta and RXR-gamma) are members of the steroid-thyroid hormone receptor superfamily of ligand-dependent transcription factors. They appear to function as auxiliary proteins that regulate high-affinity DNA binding and enhance transcriptional activity through heterodimer formation with other members of the superfamily. The RXR-alpha, RXR-beta and RXR-gamma proteins bind and are activated by the naturally occurring retinoid, 9-cis-retinoic acid. Structural similarities are apparent between retinoic acid and various eicosanoids, raising the possibility that eicosanoids may also activate retinoid receptors in vivo. We present evidence that lipoxygenase metabolites of arachidonic acid at submicromolar concentrations are capable of activating RXR-gamma activity in transient transfection assays. In addition, molecular modelling predicts conformational similarities between some lipoxygenase products and retinoic acid. Consistent with this, hydroxyeicosatetraenoic acids are known to mimic some actions of retinoids in cell-based assays. These observations raise the possibility that eicosanoids, already known to act both as local hormones and as intracellular second messengers, may also have a direct role in transcriptional activation via nuclear receptors.


The dependence of calcium-activated potassium currents on membrane potential. Previous experiments on cholinergic synapses in chick cochlear hair cells have shown that calcium entering through acetylcholine-activated synaptic channels in turn activates calcium-dependent potassium currents, resulting in synaptic inhibition. In voltage-clamp experiments such currents would be expected to increase with depolarization (as the driving force for potassium entry is increased) and then decrease towards zero as the membrane approaches the calcium equilibrium potential (when calcium entry is suppressed). In the hair cells, however, such currents approached zero at about +20 mV, more than 170 mV negative to the calcium equilibrium potential. Another feature of the synapse is its post-junctional morphology: a uniform 20 nm cleft is formed between the postsynaptic membrane and the outermost membrane of an underlying cisterna. Here we present a model in which synaptic activation results in calcium influx into the subsynaptic cleft and thence into the bulk of the cytoplasm. The model suggests that the voltage dependence of the calcium-activated potassium current can be accounted for by only two basic assumptions: (i) entry of calcium through the activated synaptic channels by simple diffusion; and (ii) activation of the potassium channels by the cooperative action of four calcium ions. In addition, the model suggests that during activation the calcium concentration in the restricted subsynaptic space can reach levels adequate to activate the potassium channels, without requiring additional, more complicated, considerations (for example, secondary calcium release from the cisterna).


Coloured noise or low-dimensional chaos? Devising a method capable of distinguishing a low-dimensional chaotic signal that might be embedded in a noisy stochastic process has become a major challenge for those involved in time-series analysis. Here a null hypothesis approach is used in conjunction with a known nonlinear predictive test, to probe for the presence of chaos in epidemiological data. A probabilistic set of rules is used to stimulate a historic record of New York City measles outbreaks, generally understood to be governed by a chaotic attractor. The simulated runs of 'surrogate data' are carefully constructed so as to be free from any underlying low-dimensional chaotic process. They therefore serve as a useful null model against which to test the observed time series. However, despite the assumed differences between the dynamics of measles outbreaks and the null model, a nonlinear predictive scheme is found to be unable to differentiate between their characteristic time series. The methodology confirms that, if there is in fact a chaotic signal in the measles data, it is extremely difficult to detect in time series of such limited length. The results have general relevance to the analysis of physical, ecological and environmental time series.


Inhaled salmeterol in the treatment of patients with moderate to severe reversible obstructive airways disease--a 3-month comparison of the efficacy and safety of twice-daily salmeterol (100 micrograms) with salmeterol (50 micrograms). Three-hundred and fifty patients with moderate to severe reversible obstructive airways disease (forced expiratory volume in 1 s or peak expiratory flow rate < or = 50% predicted, a 15% reversibility to inhaled salbutamol and symptomatic) were recruited into a multi-centre, multinational, double-blind, parallel-group randomized study. Two-hundred and eighty-three patients were randomized to receive 50 micrograms salmeterol twice daily or 100 micrograms salmeterol twice daily administered from a metered-dose inhaler for 3 months. Salbutamol (100 micrograms per metered actuation) was provided for symptomatic relief. Morning and evening peak expiratory flow rate (PEFR), day-time and night-time asthma symptoms and additional bronchodilator usage were recorded by the patient on a daily basis. Lung function and patient/physician assessment of treatment efficacy were recorded at scheduled clinic visits. Safety was determined by monitoring adverse events and standard biochemical, haematological and cardiovascular parameters. Salmeterol 100 micrograms twice daily was consistently superior to salmeterol 50 micrograms twice daily in morning and evening PEFR measurements (mean differences between the treatments: 10-14 l min-1 for morning, 95% CI-0, 22 l min-1, P = 0.047; and 10-15 l min-1 for evening, 95% CI 2, 22 l min-1, P = 0.023). The improvement in PEFR was independent of concurrent steroid usage, with the most marked improvement being seen in the more severe asthmatics requiring concurrent oral corticosteroids (mean differences between the treatments: 27-31 l min-1, 95% CI: 3,55 l m-1, P = 0.027).(ABSTRACT TRUNCATED AT 250 WORDS)


The relationship of putrescine incorporation to transferrin uptake by reticulocytes. We previously reported that putrescine incorporation occurred during transferrin uptake by rat reticulocytes (1). Both the putrescine incorporation and transferrin uptake were enhanced by the presence of Ca2+ and A23187. Furthermore, putrescine dose-dependently increased the transferrin uptake. Additionally, transglutaminase inhibitors partially blocked not only the putrescine incorporation but also the transferrin uptake.


Effect of aspirin on vascular tone and reactivity to vasoactive amines in the dog lung. The effect of increasing blood levels of aspirin on pulmonary hemodynamics and pressor response to vasoactive amines was examined in the isolated canine lung lobe, blood perfused at constant flow. At steady state lobar vascular resistance (LVR), lobes were challenged with either 250 micrograms serotonin (5-HT; n = 4), 5.0 mumol acetylcholine (ACh; n = 4) or 50 micrograms norepinephrine (NE; n = 4) before and after blood aspirin concentration [ASA] was incrementally increased from 17 to 3140 microM. LVR was partitioned into arterial (Ra) and venous (Rv) segments by venous outflow occlusions 20 min after each ASA addition and at the peak of the pressor response to each amine. ASA treatment was associated with a dose-related 105% increase in LVR (P < 0.01) accounted for by a 154% increase in Ra (P < 0.01) and a 70% increase in Rv (P < 0.01) at 3150 microM ASA (n = 12). In spite of increased vascular tone, higher [ASA] also potentiated increases in both pulmonary arterial pressure and LVR to both 5-HT and NE whereas only Ra increased with ACh challenge. Thus, the increase in pulmonary vascular tone and reactivity to vasoactive amines is positively correlated with blood aspirin levels in the dog.


[Anti-neutrophil cytoplasmic antibodies (ANCA): major progress in the diagnosis of vasculitis]. ANCA antibodies represent a family of autoantibodies directed against neutrophil enzymes. Immunofluorescence patterns allow to distinguish c-ANCAs from p-ANCAs. The detection of ANCAs is often a key element for the diagnosis of Wegener's granulomatosis, microperiarteritis, Churg-Strauss syndrome and idiopathic rapidly progressive glomerulonephritis. Although the pathogenic role of ANCAs is not firmly established, their detection often allows an early therapeutic decision in necrotizing vasculitides.


Primary stimulation of CD4+ cells in the presence of IL-4 or IFN-gamma alters the frequencies of cytokine-producing cells at restimulation. The induction of specific effector functions in naive T cells may be directed by accessory signals during activation. These could be elicited through binding to cell surface molecules or through factors secreted by antigen-presenting cells or other simultaneously activated cells. We have investigated the influence of CD8+ cells and of exogenously added cytokines (interleukin (IL)-2, IL-4 and interferon (IFN)-gamma) on the cytokine production in splenic CD4+ T cells. IL-2, IL-4, IL-5 and IFN-gamma production in CD4+ cells was measured at the single cell level during primary mitogen stimulation in vitro in the presence or absence of factors or CD8+ cells. On day 5 the cells were restimulated with mitogen alone and analysed to evaluate the short-term development of cytokine-producing cells in such cultures. Preactivation in the presence of either exogenous IL-4 or IFN-gamma led to an increased production of IL-4 and IFN-gamma respectively at restimulation, and the effects of both IL-4 and IFN-gamma were augmented by IL-2. After preactivation in the presence of IL-2 and IL-4, every third CD4+ cell could be induced to produce IL-4. Exogenous IL-4 or IFN-gamma further decreased each other's production. Depletion of CD8+ cells before activation resulted in a slight increase of IL-4-producing cells, indicating that simultaneous activation of CD8+ cells will influence lymphokine production in CD4+ cells. The results suggest that the pattern of lymphokines induced in naive cells may be influenced by factors secreted by preactivated CD4+ and CD8+ cells, and that naive cells are preferentially 'recruited' to produce similar cytokines.


Tumour necrosis factor-beta gene RFLP alleles in Finnish IDDM haplotypes. The Childhood Diabetes in Finland (DiMe) Study Group. The genes located between class II and class I HLA genes including polymorphic tumour necrosis factor (TNF) genes may contribute to the disease susceptibility in IDDM. Restriction fragment polymorphisms of the TNF-beta gene have been found to be fixed in the major IDDM susceptibility haplotypes, the B62,DR4 haplotype being associated with the 10.5-kb fragment and the B8,DR3 haplotype with a 5.5-kb fragment. We studied this TNF polymorphism in a sample of diabetic families. In all IDDM-associated haplotypes (n = 129) the 5.5-kb allele was more frequent than in haplotypes found only in healthy family members (n = 112) (58.1% versus 40.2%, P < 0.01). Among IDDM haplotypes the B62,DR4 haplotype was characterized by the 10.5-kb TNF fragment, whereas two other common Finnish IDDM-associated DR4 haplotypes--A24,B39,DR4 and A2,B56,DR4--had the 5.5-kb TNF fragment. Both IDDM-associated and non-associated DR3 positive haplotypes were linked to the 5.5-kb fragment. The distribution of various combinations of TNF alleles in IDDM probands (n = 63) did not differ from that expected according to the Hardy-Weinberg distribution. Our results indicate that the 10.5-kb allele of TNF-beta gene as such is not a risk factor contributing to DR4/DQ8-associated susceptibility. Alternatively, there may be heterogeneity in pathogenetic effector mechanisms.


Adhesion of subsets of human blood mononuclear cells to endothelial cells in vitro, as quantified by flow cytometry. Binding of leucocytes to endothelial cells (EC) is essential as an initial step in inflammatory responses. We present a rapid, non-radioactive method to measure adhesion of human lymphoid cells to EC using flow cytometry. Freshly isolated peripheral blood mononuclear cells (PBMC) were allowed to adhere to EC grown in 24-well plates. Non-adhering cells were removed, after which adhering cells and EC were dissociated using trypsin/EDTA. These samples were subsequently analysed by flow cytometry, using scatter properties to distinguish between adhering cells and EC. The ratio of the number of adhering leucocytes and EC was calculated to quantify adhesion. Results of the flow cytometric adhesion assay were comparable to those obtained with a conventional adhesion assay using chromium-labelled cells. We additionally show that by using the flow cytometric adhesion assay, adhesion of lymphocytes and monocytes present within the adhering PBMC can be quantified simultaneously. As a model, the contribution of LFA-1 (CD11a/CD18) and ICAM-1 (CD54) in adhesion of PBMC to EC was studied. It was found that adhesion of lymphocytes and monocytes is regulated differently by phorbol ester and that the relative contribution of LFA-1 and ICAM-1 differs for both cell types.


Oligoclonal T cells in rheumatoid arthritis: identification strategy and molecular characterization of a clonal T-cell receptor. Immunodominant antigens in rheumatoid arthritis (RA) should induce an expansion of T cells bearing a corresponding T-cell receptor (TCR). We therefore analysed the TCR repertoire at the site of inflammation using two fundamentally different strategies. The total TCR repertoire was examined by generating 'representative' T-cell clone panels, which were subsequently tested for clonality by restriction mapping of the TCR beta gene locus. No clonality was detected in large T-cell clone panels generated with cells from three patients. However, when we selectively analysed the TCR repertoire of in vivo pre-activated, interleukin-2 (IL-2)-responsive T cells, significant T-cell/TCR clonality was found in 2 out of 4 patients. The clonal T cells represented a minority of the total T-cell population with an estimated frequency of 1 in 300 to 1 in 1000 cells. Molecular characterization of a clonal TCR and the use of a specific TCR V beta MoAb ruled out an over-representation of T cells bearing the same V beta element in the total T-cell population, rendering the involvement of super-antigens in the induction of T-cell clonality in this case unlikely.


Taxol: the first of the taxanes, an important new class of antitumor agents. The taxanes represent the first class of antimicrotubule agents with a new mechanism of cytotoxic action since the introduction of the vinca alkaloids several decades ago. These compounds may prove to be the "anticancer drugs of the 1990s," just as the anthracyclines and the platinum compounds were the "anticancer drugs" of the 1970s and 1980s. Like the platinums, taxol, the prototypic taxane, has shown significant antineoplastic activity in patients with advanced ovarian cancer, with response rates ranging from 20% to 50%. Moreover, taxol has been shown to be useful in patients with platinum-resistant ovarian cancer. Although phase II screening is not yet complete, the results of phase II studies of taxol in advanced cancers of the ovary, breast (response rates, 56% to 62%), and lung (response rates, 21% to 24%) have rekindled interest in the microtubule as a prime strategic target for cancer therapy. After briefly reviewing the mechanisms of antineoplastic action and resistance and the results of preliminary clinical and pharmacological studies, this review will discuss several critical issues that will be addressed in future clinical trials, developmental directions, and drug supply. Although this review will focus primarily on taxol, the results of preliminary investigations with the semisynthetic taxane analog taxotere will also be discussed.


New antimetabolites in the treatment of human malignancies. Several new antimetabolites have been evaluated in clinical trials in recent years. Those with the most promising activity include the structurally related purine analogs fludarabine, 2-chlorodeoxyadenosine, and 2'-deoxycoformycin. These compounds have shown impressive activity against a broad spectrum of indolent lymphoproliferative disorders, including hairy-cell leukemia, chronic lymphocytic leukemia, and low-grade non-Hodgkin's lymphomas. They may also be useful in the treatment of acute leukemias. In contrast, they lack activity against common solid tumors. They have been generally well tolerated in large clinical trials; however, each of them is myelosuppressive and immunosuppressive. It is unlikely that any one of these drugs, when used as a single agent, will provide optimal therapy for any disease other than, possibly, hairy-cell leukemia. Combinations with other cytotoxic agents and biologics are in development, and perhaps they will lead to more effective regimens in the future.


Use of haloperidol decanoate in psychiatric diseases. Observations with slow-release neuroleptics used in the treatment of inpatients of a psychiatric ward of a general hospital have been discussed. The comparative examinations were performed within a period of two and a half years in a total of 48 patients who were ranged into two groups at random. One group received Piportil, the other Haloperidol decanoate therapy. It has to be emphasized that Haloperidol is available also in its tablet form and as short-acting injection, and is readily accessible (contrary to other products), so it is a good basis for assessing the expectable effectivity of and tolerance to depot products. When comparing the two drugs, in the course of Piportil administration neuroleptic depression developed more frequently, in one case delirium occurred which unwanted effects did not develop in the course of the administration of Haloperidol decanoate. According to our observations on a low number of cases relapse also occurred more frequently in the Piportil-treated cases. Pathological change was not observed in the results of routine laboratory examinations in the course of the administration of any of the drugs. The advantages of the use of depot products have been discussed in detail from both the physician's and the patient's aspect. Due to their beneficial antipsychotic action schizophrenic clinical conditions and especially paranoid conditions constitute the major indication field of these drugs. The use of depot products in the treatment of patients refusing therapy means a dramatic change.


Age-related polymorphism of thymus subpopulations in inbred mice. There are striking age-related changes in the demography of thymus lymphocytes, i.e. in thymus-cell subpopulations of BALB/c and SJL mice; these changes occur in the proportion of cells, identified by various markers, and by the membrane density of these markers. The thymuses of both strains undergo an age-related increase in the proportion of CD4+ CD8- cells and decrease in CD4+ CD8+ cells. Age-related changes in cells that are Pgp-1+ also show marked strain differences: Pgp-1+ cells increase in SJL, but not in BALB/c thymuses. In both strains, cells with high density of Pgp-1 appear in later life, though this is more marked in the thymus of SJL, which also shows a higher relative density at an advanced age, than do BALB/c mice. Furthermore, the per cent of cells with high density of Pgp-1 is larger in thymuses of SJL than in BALB/c mice. The percentage of CD45+ thymocytes remains unchanged, as animals age. Thymocyte-membrane densities of CD-45 undergo age-related increases in both SJL and BALB/c. The per cent of cells with high density of CD-45 is similar in both strains. Individual variations in relative size of subpopulations in SJL mice of the same age are greater in old than in young mice; this increase in heterogeneity is manifested by increase in standard deviation. Corresponding significant changes have not been observed in BALB/c or C57BL/6 mice. Thus, we have detected an intrastrain variation which may reflect age-related effects of the impact of stochastic events.


Inhibition of two-step urinary bladder carcinogenesis by the somatostatin analogue RC-160. Fisher 344 female rats were exposed for 4 weeks to the initiator carcinogen N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) 0.05% in the drinking water and thereafter to the promoter carcinogen mitomycin C (0.08 mg per animal per week) intravesically for 12 weeks. High incidence of urinary bladder transitional cell cancers was observed (17 in situ and 17 invasive carcinomas among 40 rats). When the somatostatin analogue RC-160 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2) was administered s.c. at the dose of 50 micrograms per animal per day during 6-week period of promotion with mitomycin C, the incidence of urinary bladder cancer was dramatically reduced. Only 1 in situ carcinoma was observed among 20 rats and only preblastomatous lesions (dysplasias and papillomas) occurred. This effect could indicate that RC-160 interferes with the process of promotion by induction of enhanced apoptosis (programmed cell death) of the dysplastic urothelial cells. RC-160 could be tried therapeutically for the hormonal prevention of malignant transformation of preneoplastic lesions in the urinary bladder.


[Bronchial asthma treated with long-acting beta 2 agonist. Comparison between formoterol (12 mu/g) inhaled twice daily and salbutamol (200 mu/g) inhaled 4 times daily]. Forty patients with stable asthma and daily need for inhaled beta 2-agonist, were included in a randomized double-blind study. They were treated for six weeks with inhaled beta 2-agonist, either salbutamol, 4 x 200 micrograms daily, of formoterol, 2 x 12 micrograms and 2 x placebo daily. This was preceded by a run-in period, where all patients received terbutalin-inhalation, 4 x 500 micrograms daily. Twenty patients were given formoterol and 18 salbutamol. One patient in the salbutamol-treated group discontinued treatment after three weeks, because of deterioration of asthma. On a diary card, patients recorded peak expiratory flow rate (PEFR) morning and evening before medication, score of asthma symptoms (scale 0-3; 0 = no symptoms, and 3 = severe symptoms) and use of additional doses of beta 2-agonist. Forced expiratory volume in 1 sec. (FEV1), forced vital capacity (FVC) and PEFR were obtained after 0, three and six weeks of treatment. Blinded global assessment of the treatment was performed by both patient and physician at the end of the study. During run-in the two groups of patients were different. The group subsequently treated with salbutamol had a statistical significant (ss) higher morning-PEFR, ss fewer asthma-symptom scores than one during night and ss less need for additional puffs of beta 2-agonist. During treatment, the formoterol-treated group showed an ss increase in morning-PEFR, as compared to run-in. Furthermore this group had ss fewer nocturnal symptom scores than one and ss less need for extra beta 2-agonist during night, than the salbutamol-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)


[Laparoscopic diagnosis and therapy of cryptorchism]. Between May 1987 and December 1991, laparoscopy was performed in 33 selected children with 40 nonpalpable testes, to localize the testes. Of 40 testes sought, 16 were present (14 intra-abdominal and 2 inguinal), and in 24 cases testicular aplasia was verified. The authors describe the technique of laparoscopy for unilateral and bilateral undescended testes. Exact anatomical localization of the testes by laparoscopy facilitated accurate planning of operative repair. The advantages of laparoscopy compared with ultrasound and MR imaging in 14 selected patients are described. In 3 patients with an intra-abdominal hypoplastic testis we performed laparoscopic orchiectomy. This new operative procedure is described. Laparoscopic orchiectomy is minimally invasive, offering a practicable alternative to orchiectomy in the case of an atrophic or hypoplastic abdominal testis. No complications were noted.


[Increase in the number of operations for undescended testis]. In recent years the frequency of operations for cryptorchism has been increasing, as evidence by operation protocols of boys qualified for treatment and operated on by the same surgeon in certain years. The principles of qualification for surgical treatment was evaluated on the basis of testicle position during and after the operation, testicle size, presence of inguinal hernia sac or patent vaginal peritoneal processes. It was found that the increase in the number of these operations in the hospital was not due to changes of these principles. Possible causes of increased frequency of these operations are discussed.


[Treatment of autoimmune diseases and graft rejection with anti-CD4 antibodies]. Based on the experience that T helper lymphocytes play an important part in the initiation and maintenance of various autoimmune diseases and also in graft rejection, novel therapeutic approaches have been developed and are under investigation. They are aimed at selective inhibition of T cells whose activation is unwanted. Useful tools for this purpose are monoclonal antibodies to cell surface molecules which are restricted to certain cell populations. In this review the concept of treatment with antibodies to CD4-a surface molecule characteristic of T helper lymphocytes-is discussed. Encouraged by experimental experiences obtained during the past years, a series of case reports were published and clinical pilot studies have been performed, the preliminary results of which are now becoming available. Anti-CD4 therapy appears to be a promising approach. Short-lasting effects can be separated from long-lived effects. The latter are not easy to explain, although hypotheses have been developed still requiring more detailed experimental confirmation.


Resistance of hippocampal CA-1 noradrenergic fibers to five minutes of transient cerebral ischemia in the gerbil. We examined changes in the tyrosine hydroxylase (TH)-immunoreactive fibers following 5 min of cerebral ischemia in gerbils using an immunohistochemical method 1, 3 and 30 days after ischemia. Almost all CA-1 pyramidal neurons were lost 3 days after ischemia, whereas noradrenergic fibers were maintained 30 days after ischemia. The present study demonstrated that TH-immunoreactive fibers and cells were resistant to transient ischemia, and that there was no sprouting or hyperactivity in noradrenergic systems after ischemia.


[Leydig cell tumor in a patient with type I multiple endocrine neoplasm: study of a case and review of the literature]. Presentation of the case of a 42-year old male patient with Type I Multiple Endocrine Neoplasia, known as the Wermer Syndrome, who developed Leydig's cells tumour. No association was found between both processes and therefore a fortuitus, though worthwhile mentioning given the characteristics and hormonal implications of both pathologies, can be presumed.


[Prevention and treatment of digestive hemorrhage due to ruptured esophageal varices in patients with cirrhosis]. 1) Emergency treatment. The best treatment remains endoscopic sclerotherapy, which controls the bleeding in 90% of the cases. Pharmacologic management stops the variceal hemorrhage in 80% of the cases and is indicated before endoscopic treatment can be performed. Intravenous somatostatin administration may be prolonged for 5 days, even more, and may thus prevent early rebleeding, which is not achieved neither by vasopressin nor by glypressin, which administration is restricted to 24 hours. Esophageal tamponade is useful to arrest a massive variceal bleeding, if vasoactive drugs are not available or not efficient, before endoscopic management. If the bleeding persists after 2 sclerotherapy sessions, an alternative treatment is mandatory: the patient should be sent to the surgeon for a portosystemic shunt if the operative risk is acceptable (child A and B) or should become a candidate for a transjugular intrahepatic stent shunt, especially if transplantation is considered afterwards. 2) Prevention of recurrent hemorrhage. A) Early (within 5 days after the initial bleeding). Somatostatin probably prevents early rebleeding, as do sclerotherapy. B) Late. B blockade (+ nitrates) or long-term sclerotherapy have the same efficacy. Their association may improve their results. 3) Prevention of the first bleeding episode. Propranolol decrease the risk of variceal rupture from 20% to 9% during the first year after the diagnosis of esophageal varices and is the only treatment which may be proposed to cirrhotics who did not yet bled form their varices.


Proline-specific aminopeptidases: potential role in bradykinin degradation. The N-terminus of bradykinin is shown to be sequentially degraded by the human proline-specific aminopeptidases aminopeptidase P (EC 3.4.11.9) and dipeptidyl peptidase IV (EC 3.4.14.5). Additional evidence is provided for the hypothesis that these proline-specific aminopeptidases play an essential role in the degradation of peptides containing an N-terminal Xaa-Pro sequence.


[Treatment concept of facial pain].

[Treatment concept of facial pain]. The therapy of chronic facial pain still poses an important challenge. A therapeutical scheme in four steps has been developed. This scheme enables modification of the pain therapy depending on localisation, intensity and former treatment. It consists of the following steps: 1. Transcutaneous electrical nerve stimulation. 2. Medication 3. Extracranial glycerol blocking of the trigeminal nerve 4. Neurosurgical treatment with thermocoagulation, chemical glycerol-rhizotomy and microsurgical decompression. The different therapeutical steps have no influence on each other.


A new mtDNA mutation in the tRNA(Lys) gene associated with myoclonic epilepsy and ragged-red fibers (MERRF). Myoclonic epilepsy with ragged-red fibers (MERRF) has been associated with an A--G transition at mtDNA nt 8344, within a conserved region of the tRNA(Lys) gene. Although the 8344 mutation is highly prevalent in patients with MERRF, it is not observed in 10%-20% of the cases, suggesting genetic heterogeneity. We have sequenced the tRNA(Lys) gene of five MERRF patients lacking the common 8344 mutation. One of these showed a novel T-->C transition at nucleotide position 8356, disrupting a highly conserved base pair in the T psi C stem. The mutant mtDNA population was essentially homoplasmic in muscle but was heteroplasmic in blood (47%). Neither 20 patients with other mitochondrial diseases nor 25 controls carried this mutation. These findings suggest that tRNA(Lys) alterations may play a specific role in the pathogenesis of MERRF syndrome.


Multiple origins for phenylketonuria in Europe. Phenylketonuria (PKU), a disorder of amino acid metabolism prevalent among Caucasians and other ethnic groups, is caused primarily by a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH). PKU is a highly heterogeneous disorder, with more than 60 molecular lesions identified in the PAH gene. The haplotype associations, relative frequencies, and distributions of five prevalent PAH mutations (R158Q, R261Q, IVS10nt546, R408W, and IVS12n1) were established in a comprehensive European sample population and subsequently were examined to determine the potential roles of several genetic mechanisms in explaining the present distribution of the major PKU alleles. Each of these five mutations was strongly associated with only one of the more than 70 chromosomal haplotypes defined by eight RFLPs in or near the PAH gene. These findings suggest that each of these mutations arose through a single founding event that occurred within time periods ranging from several hundred to several thousand years ago. From the significant differences observed in the relative frequencies and distributions of these five alleles throughout Europe, four of these putative founding events could be localized to specific ethnic subgroups. Together, these data suggest that there were multiple, geographically and ethnically distinct origins for PKU within the European population.


Cleft lip with or without cleft palate: associations with transforming growth factor alpha and retinoic acid receptor loci. The first association study of cleft lip with or without cleft palate (CL/P), with candidate genes, found an association with the transforming growth-factor alpha (TGFA) locus. This finding has since been replicated, in whole or in part, in three independent studies. Here we extend our original analysis of the TGFA TaqI RFLP to two other TGFA RFLPs and seven other RFLPs at five candidate genes in 117 nonsyndromic cases of CL/P and 113 controls. The other candidate genes were the retinoic acid receptor (RARA), the bcl-2 oncogene, and the homeobox genes 2F, 2G, and EN2. Significant associations with the TGFA TaqI and BamHI RFLPs were confirmed, although associations of clefting with previously reported haplotypes did not reach significance. Of particular interest, in view of the known teratogenic role of retinoic acid, was a significant association with the RARA PstI RFLP (P = .016; not corrected for multiple testing). The effect on risk of the A2 allele appears to be additive, and although the A2A2 homozygote only has an odds ratio of about 2 and recurrence risk to first-degree relatives (lambda 1) of 1.06, because it is so common it may account for as much as a third of the attributable risk of clefting. There is no evidence of interaction between the TGFA and RARA polymorphisms on risk, and jointly they appear to account for almost half the attributable risk of clefting.


Improved predictive test for MEN2, using flanking dinucleotide repeats and RFLPs. Gene(s) for the autosomal dominant endocrine cancer syndromes, multiple endocrine neoplasia type 2A (MEN2A), multiple endocrine neoplasia type 2B (MEN2B), and familial medullary thyroid carcinoma (MTC1) all map to the pericentromeric region of chromosome 10. Predictive testing for the inheritance of mutant alleles in individuals at risk for these disorders has been limited by the availability of highly informative and closely linked flanking markers. We describe the development of eight new markers, including two PCR-based dinucleotide repeat polymorphisms and six RFLPs that flank the disease loci. One of the dinucleotide repeat markers (sJRH-1) derives from the RBP3 locus on 10q11.2 and has a PIC of .88. The other dinucleotide repeat (sTCL-1) defines a new locus, D10S176, that maps by in situ hybridization to 10p11.2 and has a PIC of .68. We have constructed a new genetic linkage map of the pericentromeric region of chromosome 10, on the basis of 13 polymorphisms at six loci, which places the MEN2A locus between the dinucleotide repeat markers, with odds of 5,750:1 over the next most likely position. Using this set of markers, predictive genetic testing of 130 at-risk individuals from six families segregating MEN2A revealed that 95% were jointly informative with flanking markers, representing a significant improvement in genetic testing capabilities.


Markers of keratinocyte differentiation in snuff-induced leukoplakia. Biopsy specimens from 12 patients who used snuff and had leukoplakia in the mucosa of the oral cavity were studied and compared with specimens from their own nonleukoplakic oral mucosa, as well as with biopsy specimens from corresponding areas of the oral cavity in 12 nonsmoking, nontobacco-using control subjects. The biopsy specimens were processed using standard immunohistochemical rabbit antibody to human involucrin and mouse antibody to human transglutaminase type I as the primary antibodies. A computer-driven light absorbance image analysis system was used to determine the optical density of each of the marker-stained specimens. Optical density measurements were compared using a one-way analysis of variance. The expression of involucrin was significantly higher in the epithelium of the nonsmoking, nontobacco-using control subjects (0.2937 +/- 0.0725 optical density) in comparison with the normal-appearing mucosa (0.2283 +/- 0.0488 optical density) and the leukoplakic mucosa of the snuff-using patients (0.2007 +/- 0.0669 optical density) (p < 0.05). The expression of transglutaminase type I was also significantly higher in the epithelium of the nonsmoking, nontobacco-using controls (0.2308 +/- 0.1381 optical density) than in the patients with leukoplakic mucosa (0.1310 +/- 0.0472 optical density) (p < 0.05). However, there was no difference when compared with the normal-appearing mucosa of the patients in the snuff-using group (0.1686 +/- 0.0323 optical density). This study has shown that involucrin and transglutaminase type I are expressed differently in leukoplakic oral mucosa of snuff users and in normal oral mucosa and that this difference can be measured objectively.


Oncogene expression in follicular neoplasms of the thyroid. Oncogene expression has been found to be a potential marker for aggressive biologic behavior in certain tumors. We studied 21 follicular adenomas and 20 follicular carcinomas by immunocytochemistry utilizing specific monoclonal antibodies against HER-2/neu and c-myc oncogenes. Survival data were obtained from our institution's tumor registry. No expression of the HER-2/neu oncogene was found in the specimens studied. Cytoplasmic staining for c-myc was observed in 3 of 21 adenomas (14%) and 9 of 20 (45%) carcinomas (p < 0.05). The incidence of local, regional, and distant metastases was not significantly different in c-myc (+) and c-myc (-) patients. The c-myc oncogene is expressed more often in malignant than in benign follicular neoplasms of the thyroid, but its expression does not appear to be a good prognostic indicator.


Responses of limbic and extrapyramidal neurotensin systems to stimulants of abuse. Involvement of dopaminergic mechanisms. In summary, we have observed that drugs of abuse, which can cause schizophrenia-like paranoia, alter striatal and accumbens NT systems in a similar, dramatic fashion. The NT responses to these drugs, in particular METH, are mediated by activation of DA D1 receptors. We have observed that NMDA-type glutamate receptors are essential for the D1-NT interaction. NMDA receptors are selective, since they do not contribute to the antagonistic effects of DA D2 receptors on NT activity. This observation suggests that NT responses to D1 and D2 regulation are mediated through separate and distinct mechanisms. Finally, we found that the presence of METH dramatically reduces striatal NT release, which most likely leads to NT accumulation in nerve terminals and the observed increase in NT tissue level. The blockade of NT release by a psychotogenic drug, such as METH, is consistent with the hypothesis that NT has antipsychotic activity and a decrease in its release may contribute to some forms of schizophrenia similar to that caused by intense use of the stimulants of abuse.


Intramembrane interactions between neurotensin receptors and dopamine D2 receptors as a major mechanism for the neuroleptic-like action of neurotensin. Evidence has been presented that behavioral actions of NT, inducing its neuroleptic-like action, can be explained on the basis of NT-D2 intramembrane receptor-receptor interactions in the basal ganglia, unrelated to the coexistence phenomenon, leading to reduced affinity and transduction of the D2 agonist binding site. By reducing selectively D2 receptor transduction at the pre- and postsynaptic level, the NT receptor appears capable of switching the DA synapses towards a D1 receptor-mediated transduction, illustrating how receptor-receptor interactions can increase the functional plasticity of central synapses (FIG. 12).


Differential effects of conditioned and unconditioned stress on the neurotensin content of dopamine cell body groups of the ventral mesencephalon. The findings of this study extend the observations of Deutch et al. who suggested that NT in the ventral mesencephalon may be involved in the environmentally elicited activation of selectively responsive populations of mesotelencephalic dopamine neurons. The unconditioned response of NT-LI to electric footshock was observed only at an intensity of 500 microA and only in the lateral subdivision of the VTA. The selective effect of footshock stress on the NT content of a specific cell body group of the ventral mesencephalon suggests that NT mechanisms in the lateral VTA may, in part, underlie the stress-induced activation of dopamine neurons that originate in the lateral VTA. However, it should be noted that populations of dopamine neurons are activated by footshock intensities less than 500 microA, while NT concentrations of mesencephalic dopamine cell body groups are not altered by these shock intensities. The disparity weakens the possibility of a role for NT in the stress-induced activation of brain dopamine neurons unless NT mechanisms may be involved in transducing the effects of higher intensity stressors versus low intensity stressors. However, it should be noted that changes in the concentration of NT-LI represent an endpoint of unknown sensitivity and functional significance and best serve as an initial approximation of the effects of a manipulation on NT-containing neurons. It is plausible that NT mechanisms in the ventral mesencephalon may act in concert with other neuropeptides such as substance P and Met-enkephalin to transduce the effects of stressors on alterations in the activity of mesotelencephalic dopamine neurons that originate in the ventral mesencephalon. An examination of the effects of footshock stress on the content of prepro-NT mRNA in the dopamine cell body groups of the ventral mesencephalon would be of interest in assessing whether stress enhances NT gene expression or alters the characteristics of release of this neuropeptide in the ventral mesencephalon. Lacking NT receptor antagonists, it would also be of interest to determine the effects of the passive immunoneutralization of NT in the ventral mesencephalon on footshock-induced increases in the biochemically estimated activity of mesotelencephalic dopamine neurons to better understand the involvement of NT as a transducer of the effects of stress on dopamine neuronal activity. The distinct topography of conditioned versus unconditioned stress on the concentration of NT-LI in the dopamine cell body groups of the ventral mesencephalon suggests that NT may be involved in the differential activation of distinct dopamine neuronal populations by these different stressors.(ABSTRACT TRUNCATED AT 400 WORDS)


[A case of multiple pulmonary metastases from duodenal cancer showing partial response using 5'-DFUR and a small dose of MMC]. A 77-year-old female with primary duodenal cancer had undergone pancreatoduodenectomy in May, 1989. Postoperative chemotherapy was done in combination with MMC (mitomycin C), lentinan and UFT (combined medicine of tegafur and uracil). In August, 1991, the patient complained of a cough and then was examined for multiple pulmonary metastases from duodenal cancer by chest X-ray and CT-scan. Then, she received 5'-DFUR (400-800 mg) and MMC (total 6 mg). Two months from the start of this therapy, the cough almost vanished and pulmonary lesions were diminished markedly. For about five months, this case corresponded to partial response (PR) according to the response criteria proposed by Koyama-Saitoh. The side effects of 5'-DFUR were diarrhea and anorexia. Therefore, we think that 5'-DFUR and a small dose of MMC yielded a partial response to multiple pulmonary metastases from duodenal cancer.


Expression of the proneurotensin gene in the rat brain and its regulation by antipsychotic drugs. In this chapter, we have presented evidence for several potential levels of interaction of NT/N gene products with dopaminergic systems of the brain. We have focused on one manifestation of this interaction related to the effects of antipsychotic drugs on expression of the NT/N gene in two anatomically discrete populations of neurons. It appears that certain antipsychotic drugs can dramatically increase expression of this gene in the dorsolateral striatum by blocking dopamine D2 receptors, perhaps by increasing expression of the gene encoding the transcriptional regulator fos. In addition, a second group of NT cells in the shell region of the nucleus accumbens also respond to these drugs by increasing NT/N gene expression. Several other peptides have been suggested to respond to treatment with antipsychotic drugs. However, there are some important differences with respect to their effects on the NT cells we have studied. The most important of these is the differential responsiveness of the DLSt and nucleus accumbens NT neurons to typical and atypical antipsychotics. We showed that all antipsychotic drugs tested increased NT/N mRNA gene expression in the accumbens, a region thought to be involved in dopaminergic disturbances underlying psychosis. However, only the typical neuroleptics that have a high propensity to induce acute extrapyramidal motor side effects influenced NT/N gene expression in the dorsolateral striatum, a structure importantly involved in regulation of motor functions. We hypothesize, therefore, that NT/N-expressing neuronal systems in the nucleus accumbens may mediate some or all of the antipsychotic effects, whereas those in the dorsolateral striatum may be involved in motor effects of neuroleptic drugs. Thus, examination of the effects of these drugs on these neuronal populations will not only clarify their mechanism of action, but in addition may provide a useful "screening" assay for new drugs with enhanced antipsychotic activity, but reduced propensity to induce the debilitating extrapyramidal side effects that are a major cause of patient noncompliance. Future studies will focus on the effects of antipsychotic drugs on NT neurons in clinically relevant models of chronic administration, and on the molecular events involved in their effects on expression of the NT/N gene in the brain.


Regulated Ca2+ signalling through leukocyte CD11b/CD18 integrin. General mechanisms of adhesion in the immune response are coordinated by the leukocyte integrins CD11/CD18. The possible participation of these differentiation molecules in early events of transmembrane signalling was investigated. Monoclonal antibody (mAb) cross-linking of CD18, the integrin beta subunit ubiquitously expressed by all leukocytes, increased the cytosolic free Ca2+ concentration ([Ca2+]i) by 2-3-fold in monocyte THP-1 cells. Digitalized imaging in single adherent cells showed that this Ca2+ response is temporally biphasic, involves both release of Ca2+ from the intracellular stores as well as Ca2+ influx from the external compartment, and is dramatically down-modulated by terminal differentiation of THP-1 cells to a mature monocyte phenotype. Similarly, only a minor subset of 20-30% of peripheral blood monocytes heterogeneously maintain the CD18-mediated Ca(2+)-signalling properties. Cross-linking of CD18 also increased cytosolic free [Ca2+]i in a subset of approx. 15-20% of resting T lymphocytes, in a Ca2+ response that was completely abrogated during T-cell mitogenic activation with lectins or alloreactive antigen. While cross-linking of CD11a or CD11c was without effect, occupancy of CD11b increased cytosolic free [Ca2+]i in monocytic cells. This response was functionally coupled with a transient activation state of CD11b/CD18, which was reflected in its increased avidity to bind the complementary ligand fibrinogen. These results suggest that occupancy of CD18 transduces a stimulatory Ca2+ signal that is critically regulated by the state of cell activation/differentiation and by the association with the unique alpha-subunit CD11b. These intrinsic signalling properties may directly participate in regulating the oligospecific ligand recognition of leukocyte integrins.


Morphine analgesia in normal and alloxanized mice. The analgesic response to 10 mg/kg of morphine hydrochloride, administered intraperitoneally, was examined in mice made diabetic by treatment with alloxan using the hot plate method. The hot plate base line latency of diabetic mice was significantly higher than that of normal mice. Morphine was found to possess an hyperglycaemic effect in both normal and diabetic mice. A decreased analgesic response to morphine was observed in diabetic mice. The decreased response seemed to be associated with plasma glucose levels, since multiple injections of insulin replacement abolished the decrease in morphine analgesia in diabetic mice. However, a single injection of insulin or glucose loading did not modify morphine analgesia. Naloxone was an effective antagonist of the analgesic and hyperglycaemic effects of morphine in both normal and diabetic mice, but induced a greater reduction of the plasma glucose level in diabetic than in normal mice. It is suggested that a supranormal dose of morphine may be needed in diabetics.


Microtubule-independent choleresis and anti-cholestatic action of tauroursodeoxycholate in colchicine-treated rat liver. In order to cast light on the anti-cholestatic and cytoprotective properties of ursodeoxycholic acid (UDCA), intrahepatic transport and secretion of bile salts and biliary phospholipids were investigated by using isolated perfused livers from colchicine-pretreated rats. Administration of taurocholic acid (TCA) after colchicine pretreatment induced marked cholestasis. Tauroursodeoxycholic acid (TUDCA) treatment, in contrast, was associated with maintenance of bile flow, with excretion rates of bile acids and phospholipids similar to those in control animals. Furthermore, TCA-induced cholestasis in colchicine-treated rat livers was clearly decreased by co-administration of TUDCA. Although simultaneous addition of UDCA also showed slight improvement, with or without taurine pre-treatment, biliary bile-salt analysis also showed that cholestasis was markedly remitted as the excretion of taurine-conjugated UDCA was increased. The results suggest that the cytoprotective and anti-cholestatic effects of TUDCA may be linked to action at the intrahepatocyte level, represented by mild detergent effects on organelle lipids and preservation of intracellular transport even under microtubule-dysfunctional conditions. In addition, it was indicated that cytoprotective effects of UDCA may also be exerted after its conjugation with taurine inside hepatocytes.


Effects of nipradilol on the microvascular tone of rat mesentery: comparison with other beta-blockers and vasodilators. The effects of nipradilol, a nonselective beta-blocker with vasodilator activities, on the diameter of arterioles and venules were examined in rat mesentery in vivo and were compared with those of propranolol, atenolol, labetalol, nifedipine and nitroglycerin. Topical application of nipradilol (10(-7) M and 10(-6) M) dilated the arterioles significantly to 109 +/- 2% and 112 +/- 2% of control, respectively (mean +/- S.E.; n = 9; p < 0.01), without changes in blood pressure and pulse rate. The dilator effect was comparable to that of nifedipine and nitroglycerin. Propranolol constricted the arterioles (to 86 +/- 3% at 10(-7) M; n = 9; p < 0.01), but atenolol and labetalol had no significant effects. Nitroglycerin dilated venules significantly (to 108 +/- 2% at 10(-7) M; n = 6; p < 0.01) but other drugs showed no significant effects on the tone of venules. Unlike the other beta-blockers used in this study, nipradilol has dilator effects on arterioles as have nifedipine and nitroglycerin.


T cells and eosinophils in the pathogenesis of asthma. Persistent asthma is characterized by chronic inflammation of the bronchial mucosa, where T cells and eosinophils are prominent. This article summarizes the evidence that asthmatic bronchial inflammation is initiated and propagated by cytokines secreted by activated T cells and other cells, and describes how the release of specific cytokines could result in local preferential accumulation and activation of eosinophils.


BMY-14802 reverses the reduction of striatal dopamine release induced by (+)-3-[3-hydroxyphenyl]-N-(1-propyl)piperidine. Intraperitoneal injection of (+)-3-[3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3PPP), a sigma receptor agonist, significantly reduced the striatal levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) measured by in vivo microdialysis. These reductions were significantly greater at (+)-3PPP doses of 12 and 24 mg/kg than at 1 mg/kg. The levels of 5-hydroxyindoleacetic acid (5HIAA) were increased by the injection of (+)-3PPP in dose of 24 mg/kg, but were not affected at lower doses. BMY-14802, a sigma antagonist, alone at doses of 15 mg/kg and 30 mg/kg did not affect the levels of DA, DOPAC, HVA and 5HIAA. Pretreatment with 30 mg/kg BMY-14802 reversed the reduction of the levels of DA induced by 12 mg/kg (+)-3PPP. Although neither 30 mg/kg BMY-14802 nor 12 mg/kg (+)-3PPP affected the levels of striatal 5HIAA, combined treatment with both produced a significant elevation. These findings clearly demonstrate that sigma receptors may regulate DA release from the striatal presynapse.


Synaptically activated increases in Ca2+ concentration in hippocampal CA1 pyramidal cells are primarily due to voltage-gated Ca2+ channels. Changes in intracellular Ca2+ concentration ([Ca2+]i) in the soma and dendrites of hippocampal CA1 pyramidal neurons were measured using intracellularly injected fura-2. A large component of the [Ca2+]i elevation caused by high frequency stimulation of the Schaffer collaterals was correlated with the Na+ spikes triggered by the excitatory postsynaptic potentials (EPSPs). These spikes were generated in the soma and proximal dendrites and stimulated Ca2+ entry through voltage-gated Ca2+ channels. Suppressing spikes by hyperpolarizing the soma or by injecting QX-314 revealed a smaller nonspike component of Ca2+ entry. A substantial fraction of this component was mediated by the action of the EPSPs on voltage-gated Ca2+ channels, because it persisted in 2-amino-5-phosphonovaleric acid and because it was usually reduced when Ca2+ channel activity was suppressed by hyperpolarization. Ca2+ entry through the N-methyl-D-aspartate receptor channel could not be detected with certainty, perhaps because it was highly localized.


Ca2+ entry via postsynaptic voltage-sensitive Ca2+ channels can transiently potentiate excitatory synaptic transmission in the hippocampus. We have studied the role of Ca2+ entry via voltage-sensitive Ca2+ channels in long-term potentiation (LTP) in the CA1 region of the hippocampus. Repeated depolarizing pulses, in the presence of the NMDA receptor antagonist D-APV and without synaptic stimulation, resulted in a potentiation of excitatory postsynaptic potentials (EPSPs) or currents (EPSCs). This depolarization-induced potentiation was augmented in raised extracellular Ca2+ and was blocked by intracellular BAPTA, a Ca2+ chelator, or by nifedipine, a Ca2+ channel antagonist, indicating that the effect was mediated by Ca2+ entry via voltage-sensitive Ca2+ channels. Although the peak potentiation could be as large as 3-fold, the EPSP(C)s decayed back to baseline values within approximately 30 min. However, synaptic activation paired with depolarizing pulses in the presence of D-APV converted the transient potentiation into a sustained form. These results indicate that a rise in postsynaptic Ca2+ via voltage-sensitive Ca2+ channels can transiently potentiate synaptic transmission, but that another factor associated with synaptic transmission may be required for LTP.


Toxicology of sensory systems: a perspective. This brief review is the result of a recent meeting of the British Toxicology Society (Toxicology of Sensory Systems, University of York, April 2-3, 1992). The meeting provided the opportunity to discuss the anatomy, physiology and function of the eye, ear, nasal epithelium and peripheral sensation and the methods that are available to detect injury or dysfunction both in the preclinical and clinical situation. In addition, the mechanism whereby certain chemicals can perturb some of these organs was discussed. The aim of this short article is to highlight some of the recent advances in understanding in these areas with regard to their relevance or impact on toxicology. For convenience the areas will be discussed under separate headings.


Dose selection for toxicity studies: a protocol for determining the maximum repeatable dose. 1. A three-stage protocol is described for a dose-ranging study which defines the maximum repeatable dose (MRD) and provides a preview of the toxicology of new, pharmacologically active, substances before commencing the first formal regulatory toxicity studies, usually of 2 or 4 weeks duration. 2. Additionally, a range of toxicokinetic (TK) data relevant to protocol design for formal studies is generated. 3. Stage A is a dose incrementation process in which the MRD is provisionally determined and basic TK values generated. 4. In stage B the animals are dosed daily for at least 7 d, the MRD is substantiated and a wider range of TK data obtained. 5. In stage C, each of the dose levels identified for a formal study is administered once to investigate the relationship of doses to TK data. 6. This protocol can be completed using as few as 24 rats or six dogs (or primates). 7. Selection of dose levels for the first formal studies can be greatly aided by the results of a well-designed dose-ranging study including TK data. 8. For particularly toxic substances, the findings of studies based on this protocol have frequently been sufficiently clear to warrant early termination of their development.


Clinical course, therapy, outcome and analytical data in amitriptyline and combined amitriptyline/chlordiazepoxide overdose. A total of 103 cases of amitriptyline (AT) overdose (group 1) and 81 cases of overdose with a fixed combination of AT and chlordiazepoxide (CDE) (group 2), treated at our Intensive Care Unit or reported to our Poison Information Center between 1985-1990, were evaluated with respect to clinical course, symptoms and outcome, as well as efficacy of therapy. The mean amount of AT was considerably higher in group 1 compared to group 2 (13 mg kg-1 vs 7.7 mg kg-1). The most frequent symptoms in both groups were impaired consciousness, anticholinergic symptoms, seizures, arrhythmia and hypotension. Respiratory insufficiency necessitated respirator therapy in 63 of the patients. Two patients in group 1 and one patient in group 2 did not survive. Therapy included primary detoxification by gastric lavage and repeated administration of activated charcoal. In four of eight patients with cardiac conduction disturbances, hypertonic sodium bicarbonate led to a significant reduction in QRS duration and AV interval. Physostigmine was effective in eight of 14 patients with pronounced anticholinergic symptoms. No effect was observed in the other six patients. Haemoperfusion, which was performed in five patients, led to rapid improvement of coma after initiation of therapy in four patients. The clinical efficacy of haemoperfusion in AT overdose despite the high volume of distribution of AT deserves further investigation. The rather high average overdose of AT implies that large package sizes of AT were available to the patients. A major step towards prevention of serious AT overdose would be the prescription of package sizes containing a total of less than 500 mg AT.(ABSTRACT TRUNCATED AT 250 WORDS)


Respiratory symptoms and ventilatory capacity in metal polishers. To evaluate the long-term effects of metal dusts on the bronchopulmonary system and the synergistic effect of cigarette smoke, a comparative study of spirometric measurements in 104 polishers and 90 unexposed controls was carried out in 25 brass and steelware polishing industries at Moradabad in northern India. The two groups were comparable in terms of age, height, smoking habit and socio-economic status. A total of 58.6% of the polishers had one or more respiratory symptoms, compared to only 25.5% of the controls (P < 0.05). Chronic cough was present in 21 polishers (20.2%) as compared to 11.1% of the controls. However, this difference was insignificant. Chronic phlegm was nearly three times as frequent among the polishers as among the controls (17.5% vs 4.4%) (P < 0.005). The prevalence of dyspnoea of varying grades was also significantly higher (16.3% as opposed to 4.4%) among the exposed groups. Chronic bronchitis (6.7%) and occupational asthma (4.8%) were found to be confined to polishers. The polishers also experienced acute respiratory symptoms during the work shift. The prevalence of acute respiratory symptoms was recorded for cough in 19 workers (44.1%) followed by dyspnoea in 14 workers (32.5%) and throat irritation in 11 workers (25.5%). Comparison of the mean values of pulmonary function parameters in the polishers and the controls showed significant differences in the smoking and non-smoking groups (P < 0.001). The polishers exhibited significantly greater acute reductions in various lung functions over the work shift, particularly for forced expiratory flow over the 25-75% portion of the spirogram (FEF25-75%) FEF25% and FEF50%, than did the controls.(ABSTRACT TRUNCATED AT 250 WORDS)


Pesticide-related incidents treated in Finnish hospitals--a review of cases registered over a 5-year period. Pesticide-related incidents are uncommon in Finland. They comprised 0.11% of all hospitalizations due to poisoning in 1987-88. A search of the nationwide Hospital Discharge Register revealed 78 pesticide-related incidents in a 5-year period. Some 30 different agents were involved, the most frequent being organophosphate and MCPA. Only 36 cases (46%) were judged to be unequivocal or probable pesticide poisonings; 26 (33%) were probably other illnesses because of no or minimal exposure and of the children admitted for follow-up, nine (12%) had potentially marked exposure, but no poisoning developed owing to vigorous early treatment which limited absorption, and seven (9%) cases remained undetermined. According to our analysis, the management of patients with (suspected) pesticide poisoning at hospitals could be further improved if the following procedures were emphasised: decontamination of the skin when appropriate, systematic early estimation of the likely dose involved, analytical verification of pesticide absorption whenever feasible, and consistent collaboration with a toxicological advisory service.


Podophyllotoxin intoxication: toxic effect of Bajiaolian in herbal therapeutics. Bajiaolian (Dysosma pleianthum), one species in the Mayapple family, has been widely used as a general remedy and for the treatment of snake bite, weakness, condyloma accuminata, lymphadenopathy and tumours in China for thousands of years. However, the textbooks of traditional Chinese medicine mention little about the toxicity of Bajiaolian. Within 1 year, the authors saw five people who manifested nausea, vomiting, diarrhoea, abdominal pain, thrombocytopenia, leucopenia, abnormal liver function tests, sensory ataxia, altered consciousness and persistant peripheral tingling or numbness after drinking infusions made with Bajiaolian. The herb was recommended by either traditional Chinese medical doctors or herbal pharmacies for postpartum recovery and treatment of a neck mass, hepatoma, lumbago and dysmenorrhoea. Podophyllotoxin is one of the main ingredients of the Bajiaolian root. The clinical manifestations observed in our patients were consistent with podophyllum intoxication. Podophyllotoxin intoxication usually results from the accidental ingestion or topical application of podophyllum resin. However, these cases of Bajiaolian intoxication were iatrogenic and results from 'therapeutic doses' of Bajiaolian cited in the textbooks of traditional Chinese medicine.


Effect of glycol ethers on plasma osmolality. 1. Glycol ethers and their alkoxyacetic acid metabolites produce a linear increase in plasma osmolality with increasing plasma concentration. 2. This change in osmolality may be too small to be clinically useful at concentrations expected in cases of acute human glycol ether poisoning.


Failure of oral activated charcoal to accelerate the elimination of amiodarone and chloroquine. 1. The effect of activated charcoal on the elimination of amiodarone and chloroquine was studied in the rat. 2. The study consisted of two separate experiments. Amiodarone and chloroquine were injected subcutaneously at doses of 200 mg kg-1 and 100 mg kg-1, respectively. Six rats in both experiments were put on a charcoal-containing diet 48 h after drug administration, while the control groups remained on a normal diet. 3. Treatment with repeated oral activated charcoal had no effect on the true elimination of amiodarone and chloroquine. 4. These results suggest that, after the distribution of amiodarone and chloroquine into peripheral compartments, their rate of elimination cannot be significantly accelerated with multiple oral doses of activated charcoal.


Efficacy of whole bowel irrigation using solutions with or without adsorbent in the removal of paraquat in dogs. 1. The efficacy of whole bowel irrigation with a solution containing either polyethylene glycol (PEG) with electrolyte or an adsorbent (Kayexalate with a cathartic (sorbitol) was investigated in 18 dogs who had been given 250 mg kg-1 paraquat dichloride via a jejunal tube to eliminate the influence of gastric absorption. 2. Plasma paraquat concentrations 2 and 3 h after the initiation of bowel irrigation and at the end of the study (5 h later) were significantly lower in the bowel irrigation groups than in the control (no bowel irrigation) group. 3. The total body clearances of paraquat in the bowel irrigation groups were significantly greater than in the control group. 4. There were no significant differences between the two different irrigation solution groups in plasma paraquat concentration, the area under the plasma concentration time curve and the total body clearance. 5. In the PEG with electrolyte group, about 70% of the administered dose of paraquat was removed by means of bowel irrigation (n = 4). 6. The adjunction of the adsorbent had no beneficial effects. 7. Haemodynamic changes associated with whole bowel irrigation were unremarkable except that right atrial and pulmonary arterial pressures were elevated in the latter part of the study.


Corticosterone does not cause testicular toxicopathology in the rat: relevance to methylxanthines, ACTH and stress. 1. Methylxanthines, ACTH and stress are well known to produce testicular pathology (e.g. seminiferous tubule atrophy). Methylxanthines, ACTH and stress alter hormone secretion, particularly from the pituitary-adrenocortical system. Consequently, it has recently been suggested that there may be a causal relationship between changes in endogenous physiological adrenocortical secretions, particularly corticosterone, and testicular pathology. 2. This study tested the hypothesis that corticosterone mediates the testicular effects of both methylxanthine treatment and stress. Corticosterone was administered daily by subcutaneous injection to groups of 10 male rats at dose levels of 2 or 20 mg kg-1 in propylene glycol (1 ml kg-1) for 1 month (the shortest duration of methylxanthine or ACTH exposure known to produce testicular pathology). The highest dose of corticosterone resulted in plasma concentrations that closely matched values resulting from stress (200-700 ng ml-1) compared with controls (< 25 ng ml-1). 3. The highest dose of corticosterone caused reduced body weight gain, lower thymus, adrenal, seminal vesicle and prostate weights, but did not induce any testicular pathology. 4. That a high, but physiologically relevant, dose of corticosterone did not cause testicular pathology in this experiment excludes this steroid in the direct aetiology of methylxanthine, ACTH and stress-induced testicular pathology. Other steroids secreted from the adrenal, in combination with corticosterone, may be involved.


Toxicokinetics of colchicine in humans: analysis of tissue, plasma and urine data in ten cases. 1. A specific and sensitive radioimmunoassay was used to study the toxicokinetics of colchicine in seven cases of acute human poisoning. Post-mortem tissue concentrations of colchicine were measured in three further cases. Depending on the time of patient admission, two disposition processes could be observed. The first, in three patients, admitted early, showed a bi-exponential plasma colchicine decrease, with distribution half-lives of 30, 45 and 90 min. The second, in four patients, admitted late, showed a mono-exponential decrease. Plasma terminal half-lives ranged from 10.6 to 31.7 h for both groups. 2. Pharmacokinetic analysis of urine colchicine data was performed for two patients. The fraction of unchanged colchicine excreted in urine was about 30%, renal clearance was about 13 l h-1 and three-fold less than total body clearance (39 l h-1). The apparent volume of distribution was 21 l kg-1. 3. Post-mortem tissue analysis showed an ubiquitous colchicine distribution. Colchicine accumulated at high concentrations in the bone marrow (more than 600 ng g-1), testicle (400 ng g-1), spleen (250 ng g-1), kidney (200 ng g-1), lung (200 ng g-1) and heart (95 ng g-1); it was also found in the brain (125 ng g-1). 4. This toxicokinetic study shows that after massive ingestion, the disposition parameters and kinetics of colchicine are not markedly modified from those occurring in healthy volunteers. The absorption process was not delayed and the distribution and elimination half-lives were in the range known to occur with therapeutic doses.


Long-term study of brain lesions following soman, in comparison to DFP and metrazol poisoning. The long-term histopathological effects of acute lethal (95 micrograms kg-1) and sublethal (56 micrograms kg-1) doses of soman were studied in rats and were compared to lesions caused by equipotent doses of either another cholinesterase (ChE) inhibitor, DFP (1.8 mg kg-1), or a non-organophosphorus convulsant, metrazol (100 mg kg-1). Severe toxic signs were noted following one LD50 dose administration of all the compounds, yet only soman induced brain lesions. Moreover, even when administered at a sublethal dose (0.5 LD50), soman induced some histological changes without any clinical signs of intoxication. Soman-induced brain lesions were assessed quantitatively using a computerized image analyser. The analysis was carried out for up to 3 months following administration, and a dynamic pattern of pathology was shown. The cortical thickness and area of CA1 and CA3 cells declined significantly as early as 1 week post-exposure. No pathological findings were detected following DFP and metrazol administration. It is therefore suggested that brain lesions are not common for all ChE inhibitors and that convulsions per se are not the only factor leading to brain damage following the administration of soman. The degenerative process (found also with the sublethal dose of soman) might be due to a secondary effect, unrelated to soman's clinical toxicity, but leading to long-term brain injuries.


Diquat-induced intestinal secretion in the anaesthetized rat. 1. Diquat (1,1'-ethylene-2,2'-bipyridilium) is a non-selective desiccant herbicide which, when administered orally to mammalian species, causes significant secretion of fluid into the lumen of the gastrointestinal tract. In order to characterize this secretory response in more detail the effect of sublethal doses of diquat dibromide (DQBr2) on intestinal secretion was investigated in vivo in the jejunum of anaesthetized rats. 2. Ligated segments of jejunum (10 cm) which were prepared in groups of up to five animals were filled with 500 microliters of isosmotic DQBr2 solutions with concentrations ranging from 1-100 mM and maintained in the anaesthetized rat for 1, 2 or 3 h; in control experiments a solution of 100 mM NaBr was used. 3. It was found that while all of the fluid instilled into the segments was absorbed in the control experiments, there was both a dose- and time-dependent secretory response to DQBr2. Maximal fluid secretion occurred after treatment with 50 mM DQBr2 for 3 h. 4. Histological assessment of the jejunum revealed an increase in cell exfoliation and evidence of luminal distension after incubation with DQBr2. However, no structural damage to the mucosa could be seen to account for the fluid secretion. 5. The model described provides a quantitative means of evaluating intestinal secretion and may be used for elucidating the mechanism by which diquat alters fluid transport processes.


Intrapleural administration of fibres induces mesothelioma in rats in the same relative order of hazard as occurs in man after exposure. 1. The dose-response data for the induction of mesothelioma, in rats, by the intrapleural administration of the fibrous zeolite, erionite, has been compared to the published data for the crocidolite and chrysotile forms of asbestos. Erionite is more than two orders of magnitude more carcinogenic than either of the two forms of asbestos examined. 2. The relative sensitivity of the intrapleural and intraperitoneal routes of injection were also examined. The sensitivity of the intraperitoneal over the intrapleural route of administration was considerably greater for all the forms of asbestos examined but not for erionite. 3. The relationship for different fibres, between the number of fibres required to give animals mesothelioma, at the 50% or 10% observable tumour effect level (OTEL) was examined, and a ranking of relative carcinogenicity was made. 4. This showed that the data derived from the dose responses obtained by the intrapleural administration of fibres to rats ranked the relative carcinogenicity of erionite, crocidolite and chrysotile in accord with the known clinical mesothelioma induction in man after exposure to these fibres. Examination of the carcinogenicity ranking from data derived from intraperitoneal injections of fibres was not in accord with the known clinical mesothelioma induction in man for the various asbestos types examined.


Neurotoxic effects induced by intracerebral and systemic injection of paraquat in rats. 1 The neurotoxic effects elicited by paraquat after systemic and intracerebral injection were studied in rats. 2 Intrahippocampal microinfusion of paraquat (0.1 mumol) produced behavioural stimulation and electrocortical (ECoG) excitation followed, at 24 h, by multifocal brain damage. Similarly, microinfusion of paraquat (0.2-0.4 mumol) into the locus coeruleus, substantia nigra or into the raphe nuclei, where noradrenergic, dopaminergic and serotonergic neurons are present, respectively, elicited potent excitotoxic effects (n = 6 rats per dose and area). A lower dose (0.01 mumol) of the herbicide or injection of the vehicle (1.0 microliter) did not produce any behavioural, ECoG or neurodegenerative effect. 3 After systemic administration, paraquat (20 mg kg-1 s.c.) evoked limbic motor seizures and ECoG epileptogenic discharges; in 10 out of 15 treated rats neuronal cell death was observed in the pyriform cortex, but not in other brain regions. A dose of 5 mg kg-1 was ineffective. 4 Among the regions of the brain studied, high concentrations of paraquat were detected in the pyriform cortex 24 h after systemic administration (5.0 and 20 mg kg-1 s.c.) lower levels being observed in the caudate nucleus. 5 In conclusion, paraquat, given systemically or intracerebrally in rats produces neurodegenerative effects.


Double fatal inhalation of dichloromethane. 1 Two cases of lethal poisoning following acute inhalation of extremely high concentrations of dichloromethane (DCM) are reported. The concentrations of the solvent found in the blood of the two subjects collected at autopsy and analysed by gas chromatography/mass spectrometry (572 and 601 mg l-1) were compatible with those measured in the air a few hours after the discovery of the bodies (up to 168,000 ppm). 2 Extensive brain and lung oedema and congestion, microhaemorrhagic changes of the stomach and congestion in other organs were observed on macroscopic and microscopic examination of both subjects. In addition, and in both cases, high but not lethal carboxyhaemoglobin (COHb) levels (30%) were found in the blood collected at autopsy. 3 Narcosis and respiratory depression due to the effect of DCM on the central nervous system (CNS) appear to have played a critical role in the death of the two men. However, biotransformation of the solvent to toxic metabolites, including carbon monoxide (via oxidative dehalogenation by the cytochrome P450-dependent mixed function oxidase system) or formaldehyde, formic acid, inorganic chloride and carbon dioxide (via the glutathione-S-transferase pathway) may have also contributed significantly to fatal toxicity.


Safety warnings and first aid instructions on consumer and pharmaceutical products in Nigeria: are they adequate? An investigation into the adequacy of safety warnings and first aid instruction on 357 consumer and pharmaceutical product labels was carried out. The results show that 23% of the products carried correct and appropriate information while 34% had neither warning nor first aid instructions. About 15% had copiously written instructions and/or warnings and 15% showed partially correct instructions. Only about 4% of the products described warning signs and gave directions for the full treatment of poisoning and 3% recommended calling a health professional in the case of poisoning.


Clinical experience in the therapy of bites from exotic snakes in Berlin. Since there are nearly no indigenous poisonous snakes in Germany, snake bites by poisonous snakes are rare. Most serious snake bites reported to poison information centres or treated at hospitals are caused by exotic snakes that are kept in private households. Only few types of antivenom are stored in emergency depots in Germany including polyvalent antivenoms from commercial sources. Since experience with the treatment of poisonous snake bites is limited, the records of the Intensive Care Unit and the Poison Information Centre of the Universitätsklinikum Rudolf Virchow from 1980-1991 were evaluated. During this period, 51 snake bites were reported. Eleven patients who had been bitten by exotic poisonous snakes were treated in intensive care. In eight of the cases, ethanol (blood levels on admission 1.2-4.2 g-1) had played an important role in the cause of the bite. A moderate to severe local inflammation at the site of the bite followed by oedema and necrosis was typical. One patient developed respiratory failure, probably because of the neurotoxic effects of the snake venom and a compartment syndrome necessitating fasciotomy. Haemolysis was observed in four patients and coagulopathy in six patients. All patients received polyvalent antivenom within 2-12 h of the snake bite. Despite serious coagulopathy in two of the patients and respiratory arrest in one, all survived without sequelae.


Difenacoum poisoning as a cause of haematuria. A man presented with frank haematuria and a grossly prolonged prothrombin time. He was later found to have taken an overdose of difenacoum--a 'superwarfarin' rodenticide. The diagnosis was confirmed by a serum concentration of difenacoum of 0.6 micrograms ml-1. Overdosage with superwarfarins is discussed and the need for prolonged treatment with vitamin K1 highlighted.


Glutathione conjugation and pharmacokinetics of 2-bromo-3-phenylpropionic acid in vitro and in the rat in vivo. Glutathione (GSH) conjugation of the chiral compound 2-bromo-3-phenylpropionic acid (BPP) was studied in vitro and in the rat in vivo. GSH conjugation of BPP, catalyzed by a mixture of glutathione-S-transferases (GST's) from rat liver cytosol in vitro, was stereoselective: at a substrate concentration of 250 microM, (R)-BPP was more rapidly conjugated than (S)-BPP (R/S-ratio = 2.6). The blood elimination kinetics of the separate BPP enantiomers and the biliary excretion kinetics of the corresponding GSH conjugates were studied in the rat in vivo after administration of (R)- or (S)-BPP at a dose level of 50 mumol/kg. Elimination of (R)-BPP from blood was faster than that of (S)-BPP: half lives were 9 +/- 2 min for (R)-BPP and 13 +/- 1 min for (S)-BPP. The biliary excretion rate of the GSH conjugate of (R)-BPP declined monoexponentially, while that of the GSH conjugate of (S)-BPP displayed a biphasic profile. Half lives of excretion were 13 +/- 1 for the GSH conjugate of (R)-BPP, and 11 +/- 2 for the GSH conjugate of (S)-BPP (second phase). The first phase in the biliary excretion of the GSH conjugate of (S)-BPP could not be attributed to capacity limitation of biliary transport carriers as higher excretion rates were attained upon administration of higher doses (100 and 200 mumol/kg) of (S)-BPP). The blood elimination profiles of (R)- and (S)-BPP differed greatly from the biliary excretion profiles of the corresponding GSH conjugates. This suggests that the kinetics of BPP conjugate excretion are determined by other processes than hepatic GSH conjugation.


Resolution and adrenergic activities of the optical isomers of 4-[1-(1-naphthyl)ethyl]-1H-imidazole. Recently we synthesized a naphthalene analog of medetomidine, 4-[1-(1-naphthyl)ethyl]-1H-imidazole hydrochloride (1), and found it to be highly potent in adrenergic systems. The separation of optical isomers of this naphthalene analog was achieved by using the isomers of tartaric acid. The optical purities of the isomers were determined by HPLC using a chiral column. Using X-ray analysis the (+)-isomer was determined to have the S absolute configuration. It has been reported that the (+)-isomer of medetomidine (2) is the most potent enantiomer on alpha 2-adrenergic receptors. There were both qualitative and quantitative differences in biological activities of the optical isomers of 1 in alpha 1- and alpha 2-adrenergic receptor systems of guinea pig ileum and human platelets. (+)-(S)-1, but not (-)-(R)-1 was a selective agonist of alpha 2-mediated responses in ileum whereas (-)-(R)-1 was more potent than (+)-(S)-1 as an inhibitor of alpha 2-mediated platelet aggregation.


PCNA-dependent DNA polymerase delta from rabbit bone marrow. Proliferating cell nuclear antigen (PCNA) and PCNA-dependent DNA polymerase delta were partially purified and characterized from rabbit bone marrow. Rabbit DNA polymerase delta sediments at 8.2 S upon glycerol density gradient centrifugation. Similar to calf thymus PCNA-dependent DNA polymerase delta, a 125-123-kDa doublet and 48-kDa polypeptides correlate with DNA polymerase activity. Western blotting of rabbit DNA polymerase delta with polyclonal antibody to calf thymus PCNA-dependent DNA polymerase delta gives the same results as calf thymus delta; the 125-123-kDa doublet is recognized. PCNA-dependent DNA polymerase delta is resistant to inhibition by dideoxynucleotides and is relatively insensitive to inhibition by N2-[p-(n-butyl)phenyl]dGTP. A 3'-->5' exonuclease copurifies with the DNA polymerase. The processivity of DNA polymerase delta alone is very low but greatly increases with the addition of PCNA from rabbit bone marrow or calf thymus. Comparative studies of the original DNA polymerase delta from rabbit bone marrow demonstrate a lack of recognition by antibodies to calf thymus delta and a high degree of processivity in the absence of PCNA. Additionally, the originally described DNA polymerase delta is a single polypeptide of 122 kDa. These features would recategorize the original delta to the epsilon category by recently proposed convention. PCNA-dependent DNA polymerase delta is a relatively minor component of rabbit bone marrow compared to DNA polymerase alpha and PCNA-independent DNA polymerase delta (epsilon), the relative proportions being alpha, 60%; delta, 7%; and epsilon, 30%.


Determination of immunoreactivity of doxorubicin antibody immunoconjugates by a Le(y) competitive RIA. Many monoclonal antibody-drug immunoconjugates have been evaluated for their ability to deliver cytotoxic drugs to tumors. It is essential to establish that the ability of the conjugates to bind antigen, i.e. their immunoreactivity, is not adversely affected by the drug conjugation procedure. We have described herein a measurement of the immunoreactivity of BR96-DOX, a conjugate comprised of BR96, a chimeric monoclonal antibody specific for the Le(y) tetrasaccharide commonly expressed on human carcinomas, and doxorubicin, an anticancer agent in widespread clinical use. We have employed a competitive RIA, in which microtiter wells were coated with synthetic Le(y) conjugated to human serum albumin and then incubated with 125I-labeled antibody BR96 in the presence of test conjugate or intact BR96 mAb. The test conjugates were found to compete as effectively as unconjugated BR96. This assay is highly applicable to QC processes with the intra-assay CV = 2.0% and the interassay CV = 4.3%.


A cdc2 gene of Petunia hybrida is differentially expressed in leaves, protoplasts and during various cell cycle phases. Analysis of p34cdc2 kinase in higher eukaryotes has demonstrated that p34cdc2 function is conserved in all eukaryotic cells. The p34cdc2 kinase (the product of the cdc2 gene) is required during the G1 cell cycle phase at the initiation of DNA replication and also in G2-M phases for entry into mitosis. In this paper we report the isolation and characterization of a cdc2 Petunia hybrida PCR fragment (cdc2Pet). Using a DNA probe based on this fragment and a p34cdc2-specific antibody, cdc2Pet transcript and p34 protein levels were found to be constant both in 2C nuclei of highly proliferating mesophyll 2C cells derived from protoplasts and in 2C nuclei isolated directly from expanded petunia leaves. Both the cdc2Pet transcript and p34cdc2 protein levels were found to be higher in nuclei at 4C than in those at 2C, even when these 4C nuclei were from non-proliferating tissue. Thus cdc2Pet mRNA and protein levels measured in different tissues should not be interpreted to reflect exclusively the proliferative state of the tissue but also the frequency of G2 cells including those in the differentiated state.


Ovariectomy promotes the growth of altered hepatic foci after withdrawal and reintroduction of phenobarbital during hepatocarcinogenesis in rats. Female F344/N rats were given 70% partial hepatectomies and intubated with diethyl-nitrosamine (DEN, 10 mg/kg) 24 hours later. They were fed a cereal-based diet, NIH-07 (NIH) + 0.05% phenobarbital (PB) for 6 months, at which time NIH + PB was withdrawn and the rats were ovariectomized (OV) or sham-operated (SH). Groups of 7-10 rats were fed a semipurified diet (AIN-76) for 1 or 2 months after withdrawal of NIH + PB, or NIH + PB for 2 months, or AIN-76 diet for 1 month and subsequently NIH + PB for 1 month. Placental glutathione S-transferase (PGST)- and gamma-glutamyltransferase (GGT)-positive (+) altered hepatic foci (AHF) were analysed by quantitative stereology. Ovariectomy stimulated growth of AHF after withdrawal and reintroduction of NIH + PB. AHF, especially PGST+ AHF, continued to regress throughout the PB withdrawal period in rats fed AIN-76 diet. In most studies of chemical hepatocarcinogenesis, females have been shown to develop a greater volume of AHF than males. In our study, however, ovariectomy stimulated the growth of AHF after withdrawal and reintroduction of PB. Because AHF occurring spontaneously in male rats develop more rapidly than in female rats, the greater rate of growth of AHF in OV female rats may reflect a similar mechanism.


Isolation and characterization of equinatoxins from the sea anemone Actinia equina L. Equinatoxins were purified from the tentacles and bodies of the sea anemone Actinia equina by the use of acetone precipitation, as well as column chromatographies on Sephadex G-50 and CM-cellulose according to the modified method of Macek and Lebez (1988). The equinatoxins obtained, equinatoxin 1 and 2, were hemolytic glycoproteins with a relative molecular mass of 20000. Equinatoxin 2 was found to be rich in glycine, alanine and valine. The amino acid sequences of equinatoxins 1 and 2 were partially determined. A portion of the N-terminal amino acid sequence of equinatoxin 2 was similar to those of pyruvate kinase and sialidase.


Quantitative determination of CGS 18102A, a new anxiolytic, in human plasma using capillary gas chromatography/mass spectrometry. CGS 18102A is a novel hexahydrobenzopyranopyridine that has a mixed pharmacological profile of 5-HT-1A agonist and 5-HT-2 antagonist properties. Based upon these mechanisms, the compound is predicted to have anxiolytic efficacy with possible efficacy in depression. Preclinical studies in the rat have shown the drug to be well absorbed and extensively metabolized. Because of the anticipated low plasma levels in humans a gas chromatography/mass spectrometry (GC/MS) analytical method has been developed and validated to determine plasma concentrations of CGS 18102A in early clinical studies. The method utilizes CGS 18416A as the internal standard. Samples (1 mL) were extracted with pentane:ethyl acetate (75:25, v:v). Extracts were then concentrated and analysed directly by GC/MS. Separation was accomplished on a methylsilicone capillary column (30 m x 0.32 mm i.d.). GC/MS was carried out under positive ion ammonia CI conditions, with selected ion monitoring of the [M + H]+ ions (m/z = 262 and 248) for CGS 18102A and CGS 18416A, respectively. The method was successively applied to the analysis of clinical samples from an ascending multidose safety and tolerability study conducted in six normal healthy male volunteers.