Purification of HlyX, a potential regulator of haemolysin synthesis, and properties of HlyX:FNR hybrids.

The hlyX gene of the swine pathogen Actinobacillus pleuropneumoniae is homologous to FNR, an anaerobic transcriptional regulator of Escherichia coli. It endows a haemolytic phenotype upon E. coli, and will complement the anaerobic respiratory deficiencies of fnr mutants of E. coli. The coding region of the hlyX gene was expressed in E. coli and the HlyX protein was purified by using an assay based on its immunological cross-reactivity with anti-FNR antibodies. The HlyX protein had the predicted N-terminal sequence, and resembled the isolated FNR protein in size (Mr 29,000) and monomeric organization. It has no detectable haemolysin activity per se, and is therefore presumed to confer a haemolytic phenotype by activating a latent haemolysin gene in E. coli. Studies with gene fusions showed that HlyX, like FNR, can function as an anaerobic activator and repressor of FNR-regulated genes in vivo. Plasmids that express hybrid HlyX:FNR proteins in which the 189/190-residue N-terminal segments and the remaining 50/60-residue C-terminal segments are exchanged, retained their FNR-specific functions but failed to confer a haemolytic phenotype. This suggests that the specificity for activating the haemolytic response requires the participation of unique features in both the N- and C-terminal segments of HlyX.


Replication origins and pause sites in sea urchin mitochondrial DNA.

We have used a combination of one- and two-dimensional agarose gel electrophoresis, and solution hybridization to strand-specific probes, to map the replication origin of sea urchin mitochondrial DNA and to investigate the structure of replication intermediates. These assays are consistent with replication initiating unidirectionally from the D-loop region by D-loop expansion, as in vertebrates. A prominent site of initiation of lagging-strand synthesis lies at, or near to, the boundary between the genes for ATPase 6 and COIII, which is also close to a pause site for leading-strand synthesis. These findings suggest a role for pause sites in the regulation of mitochondrial transcription and replication, possibly involving template-binding proteins.


Influence of the bathing medium on the contractile responses of the rabbit urinary bladder.

This study examined contractile responses of the in vitro rabbit whole-bladder preparation to field stimulation, bethanechol and KCl in Tyrode's solution and minimum essential medium (MEM). We found frequency-dependent increases in intravesical pressure in bladders incubated in Tyrode's solution and MEM. However, bladders incubated in MEM consistently responded with greater increases in intravesical pressure compared to those incubated in Tyrode's solution. Similarly, there were frequency-dependent increases in the rate of pressure generation in bladders incubated in Tyrode's solution and MEM, and bladders incubated in MEM responded with greater rates of pressure generation than those incubated in Tyrode's solution at frequencies of 1, 2 and 4 Hz. In addition, there were significant increases in intravesical pressure generated in response to administration of 500 mmol/l bethanechol and 186.4 mmol/l KCl in bladders incubated in MEM compared to Tyrode's solution but no changes in the rate of pressure generation. The influence of L-methionine, one of the constituents of MEM, on the responses of whole bladders to nerve stimulation was also investigated. L-methionine at concentrations of 0.1 and 1.0 mmol/l had no effects on the increase in intravesical pressure or rate of pressure generation following nerve stimulation. It is speculated that the increases in contractile responsiveness of bladders incubated in MEM are related to the combination of amino acids, vitamins and other constituents of the cell culture medium.


The Croonian Lecture, 1992. The key role of the thymus in the body's defence strategies.

For centuries the thymus has remained a mysterious organ with largely unknown functions. The first demonstration of its crucial role in the development of the immune system was reported in 1961, when it was found that mice thymectomized at birth had poorly developed lymphoid tissues, impaired immune reactivities, and an inordinate susceptibility to develop infections. Although thymus lymphocytes were for a long time deemed immunoincompetent, it was shown in 1967 that they could respond to antigen by proliferating to give rise to a progeny of cells which did not secrete antibody (T cells), but which had a remarkable ability to induce bone marrow cells (B cells) to become antibody formers. This was the first unequivocal demonstration of a major division of labour among mammalian lymphocytes. Tremendous progress in our understanding of the function of the thymus and of the T cells derived from it followed. Distinct T cell subsets were characterized and shown to have an essential role in initiating and regulating a variety of immune responses. The ontogenetic events which occurred during their differentiation were mapped, and this allowed studies of the selection of the T cell repertoire. The major histocompatibility complex and associated peptides were shown to govern T cell selection and antigen activation, and the antigen-specific T cell receptor and the genes which code for it were characterized. Future studies should allow some insight into how to activate T cells more effectively for vaccination purposes, and how to switch them off to prevent autoimmune reactions and to induce tolerance to transplanted tissues.


Central and peripheral effects of repeated stress and high NaCl diet on neuropeptide Y.

This study was performed to investigate the influence of repeated psychological stress alone or combined with high NaCl intake on the function of the sympathetic nervous system. In addition, NPY levels have been measured in brain regions of potential importance in the central regulation of stress responses (ventrolateral and dorsomedial medulla, paraventricular and arcuate nucleus of the hypothalamus, and frontal cortex). Normotensive Wistar rats received a standard diet alone or supplemented with NaCl. To accentuate differences in sodium balance, rats on the high NaCl diet (HNa) were uninephrectomized. Half the animals on each diet were subjected to chronic stress using daily sessions (1 h) of immobilization stress. After 12 days, plasma levels of neuropeptide Y (NPY), norepinephrine (NE), and epinephrine (E) were measured basally and in response to acute footshock stress. HNa intake or chronic stress alone did not significantly alter either basal or stimulated plasma levels of NPY. However, combining the treatments produced a significant interaction, increasing the NPY response to footshock by 31% compared to HNa alone (p = 0.039) and by 98% compared to stress alone (p less than 0.001). Chronic stress increased basal levels of NE and enhanced the response to subsequent acute stress: combining the treatments did not yield further increases. Plasma levels of E were not significantly affected by the treatments. In the brain, stress alone had no effect on the NPY levels in the structures studied. HNa intake induced a significant increase in NPY levels of the arcuate nucleus, and produced a significant interaction with stress in the dorsomedial medulla. In a supplementary experiment, to evaluate the role of the autonomic nervous system in plasma NPY responses, treatment with the ganglion blocker hexamethonium was shown to significantly attenuate stress-induced changes in NPY, NE, and E.


Effects of brain natriuretic peptide-32 on the extinction of active avoidance behavior in rats. Transmitter-mediated action.

Three doses of porcine brain natriuretic peptide (pBNP-32) were tested in regards to the extinction of active avoidance behavior following injection into the lateral brain ventricle in rats. This peptide delayed the extinction of the active avoidance reflex in a dose-dependent manner. To clarify the involvement of transmitters in the action of the peptide, the animals were pretreated with different receptor blockers in doses that did not affect the behavior of the animals in this learning paradigm. Dopaminergic, cholinergic, and alpha- and beta-adrenergic blockers effectively blocked the delaying action of pBNP-32, whereas GABAergic, serotoninergic, and opiateergic blockers were ineffective. The data suggest that the delaying action of pBNP-32 on the extinction of active avoidance behavior is mediated via dopaminergic and alpha- and beta-adrenergic neuromediations.


Neuroendocrine and behavioral responses during conditioned active and passive behavior in the defensive burying/probe avoidance paradigm: effects of ipsapirone.

Plasma epinephrine (E), norepinephrine (NE), and corticosterone (CORT) concentrations were determined in the rat before, during, and after a 15-min exposure to a nonelectrified probe on day after receiving electric shock (1.5 mA) through a probe mounted on the wall of the home cage. Rats displayed burying (active coping) if sawdust was provided on the floor and immobility (passive coping) if bedding was absent both during training and testing. The conditioned burying was accompanied by high plasma NE but low E and CORT concentrations, whereas immobility was associated with high CORT and low NE levels. A forced switch from the active to passive coping (training with and testing without sawdust) led to the highest rise in E concentration. The 5-HT1A agonist ipsapirone, with anxiolytic properties, dose-dependently (0.5 and 2.5 mg/kg, IV) reduced defensive burying behavior and increased the amount of time spent on feeding behavior in the presence of bedding material. Both plasma E and CORT levels were further elevated by the higher dose of ipsapirone. In the absence of bedding material, ipsapirone failed to affect immobility behavior, but it dose-dependently elevated the stress-induced increase in E, NE, and CORT concentrations. Accordingly, the behavioral anxiolytic action of the 5-HT1A agonist ipsapirone was restricted to active coping, whereas neuroendocrine activation by the drug was present in all conditions. It is suggested that the effects of ipsapirone on behavioral coping and neuroendocrine regulation are produced by different populations of 5-HT1A receptors in the brain.


Psychopharmacological responsiveness to the dopamine agonist quinpirole in normal weanlings and in weanling offspring exposed gestationally to cocaine.

The behavioral responsiveness to challenge doses of the D2 agonist quinpirole was examined in 21-day-old normal offspring (experiment 1) as well as offspring exposed gestationally to cocaine (experiment 2). In both experiments weanling rats received a subcutaneous injection of 0 (0.9% saline), 0.04, 0.08, 0.5, or 1.0 mg/kg/3 cc of the D2 agonist quinpirole and were placed in a divided glass testing apparatus containing either a dish of wet mash plus a food pellet or wood block (experiment 1) or both a food pellet and a wood block (experiment 2). Behaviors were recorded for 5 min via time-sampling at 30 and 60 min post-injection. In experiment 1 the three highest doses of quinpirole increased the amount of forward locomotion, rearing, sniffing and probing, as well as increasing directed oral movements at both the wood block and food pellet; in general these findings are reminiscent of those reported previously in adult animals. In experiment 2, cocaine-exposed weanlings exhibited an increased sensitivity to the stimulating effects of a low dose of the D2 agonist for forward locomotion and rearing as well as an increase in the overall incidence of sniffing behavior and chewing on food pellets. These data provide psychopharmacological evidence that the increase in striatal D2 binding previously observed in weanling offspring exposed gestationally to cocaine (Scalzo et al. 1990) may be associated with an increased behavioral sensitivity to the D2 agonist quinpirole.


Chronic infusion of clonidine does not alleviate spontaneous morphine withdrawal symptoms in rats.

Opiate withdrawal is associated with behavioural symptoms and a sympathetic hyperactivity, the latter being sensitive to clonidine. The central question is whether behavioural symptoms would be also sensitive to clonidine. A rat model was used in which the locomotor activity was measured 24 h a day during the morphine withdrawal phase. Spontaneous withdrawal of morphine reduced strongly the high nocturnal locomotor activity, concomitantly decreasing food intake and body weight. Chronic infusion of clonidine (30-120 micrograms/kg/day) using osmotic minipumps had no effect on the withdrawal symptoms. Higher dosages (250-1000 micrograms/kg/day) potentiated rather than alleviated the withdrawal symptoms, suggesting an alpha 1-adrenergic effect of clonidine rather than an alpha 2-action. Therefore, we studied the action of a more specific alpha 2-agonist UK-14.304. UK-14.304 was less potent than clonidine in naive animals. It slightly alleviates the decrease of nocturnal activity during spontaneous morphine withdrawal. Furthermore, we have tested whether the effects of high dosages of clonidine could be altered by a specific alpha 1-antagonist doxazosine. Doxazosine reduced only slightly the potentiation in the decrease in food intake by clonidine during morphine withdrawal. For the other symptoms no interaction between doxazosine and clonidine was found. The data suggest that the use of clonidine in the detoxification of opiate dependent people is based on the suppression of the sympathetic hyperactivity rather than on symptoms with a more behavioural character.


Effects of buspirone and gepirone on i.v. cocaine self-administration in rhesus monkeys.

Buspirone and gepirone were evaluated as potential pharmacotherapies for cocaine abuse by studying the effects of acute and repeated treatment on IV cocaine self-administration in rhesus monkeys. Chlorpromazine was also evaluated as a positive control. Effects of IV drug pretreatments were tested during daily 60-min sessions with lever-pressing reinforced under a fixed-ratio 10 schedule of 0.02 or 0.05 mg/kg cocaine infusions. Acute pretreatment with buspirone (0.1 and 0.3 mg/kg, IV) increased rates of cocaine self-administration without disrupting food pellet consumption. Some doses of buspirone also produced changes in rates of cocaine self-administration without altering the within-session pattern of responding. In contrast, acute doses of gepirone had little effect on rates of cocaine self-administration, while disruptions in food consumption and changes in the within-session pattern of cocaine self-administration were obtained at the highest dose of gepirone tested (1.0 mg/kg). When either buspirone (0.1 and 0.3 mg/kg, IV) or gepirone (0.1 mg/kg, IV) were administered daily for 10 days, consistent effects on cocaine self-administration were not observed. Thus, the effects of acute buspirone administration on cocaine-maintained behavior were similar to the effects produced by chlorpromazine and other dopaminergic antagonists, whereas, gepirone was ineffective. These results provide some support for further evaluation of buspirone as a potential pharmacotherapy for cocaine abuse, although its lack of efficacy with repeated treatment is not encouraging. The negative results with gepirone provide less rationale for continued investigations with this drug, possibly because of its lesser involvement than buspirone with dopaminergic neurotransmission.


Dose-response relationship for oral idazoxan effects in healthy human subjects: comparison with oral yohimbine.

The effects of oral administration of the alpha 2 adrenergic receptor antagonists idazoxan (20 mg, 40 mg, 80 mg) and yohimbine (20 mg) were compared using a placebo-controlled within-subjects design. Healthy subjects completed 5 test days during which medication effects on mood and anxiety states, physiologic indices, plasma cortisol levels, and plasma levels of the norepinephrine metabolite 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) were assessed. Idazoxan dose-dependently increased plasma MHPG, plasma cortisol, systolic and diastolic blood pressure, and Panic Attack Symptom Scale scores in healthy subjects. Overall, yohimbine and idazoxan produced a similar pattern of behavioral and neuroendocrine responses. Since idazoxan possesses relatively greater receptor specificity compared to yohimbine, it may be a more useful alpha 2 antagonist in humans.


Differences between antipsychotic drugs in persistence of brain levels and behavioral effects.

After a single dose of the butyrophenone neuroleptic haloperidol, behavioral effects and detectable drug levels in rat brain can last for several weeks. To determine if such persistence is a general property of neuroleptics, we compared drug levels and effects after IP administration of two butyrophenones (haloperidol and bromperidol), a high potency (fluphenazine) and a low potency (chlorpromazine) phenothiazine. Drug levels in brain tissue were measured by high pressure liquid chromatography and behavioral effects monitored as inhibition of apomorphine-induced stereotypy. Estimated near terminal elimination half-lives (t 1/2) from brain for acutely administered chlorpromazine (20 mg/kg) and fluphenazine (1 mg/kg) were 0.41 and 0.62 days, respectively, and neither drug was detectable after 4 days. Fluphenazine given daily for 5 days showed an only slightly slower elimination (t 1/2 = 1.1 days). In contrast, near-terminal elimination half-lives from brain for haloperidol and bromperidol (both at 1 mg/kg, IP) were much longer (6.6 and 5.8 days, respectively), and each was detectable for 21 days after dosing. Inhibition of apomorphine-induced stereotypy correlated highly (r = 0.95) with brain levels of haloperidol. For fluphenazine, given once or repeatedly, early inhibition was replaced within 1 week by supersensitivity to apomorphine which persisted for up to 3 weeks. These findings, indicating marked differences in clearance and recovery times after dosing with butyrophenones and phenothiazines, have clear implications for studies of the effects of neuroleptic drugs in rats.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of acute and chronic desipramine treatment on somatostatin receptors in brain.

The effects of acute (5 mg/kg, IP twice daily for 2 days) and chronic (5 mg/kg IP twice daily for 21 days) administration of desipramine (DMI) on [125I]-Tyr11-somatostatin binding sites in brain were examined. There was no change in [125I]Tyr11-somatostatin binding in membranes prepared from the frontal cortex, striatum, and hippocampus of rats acutely or chronically treated with DMI as compared to non treated animals. [125I]Tyr11-somatostatin binding was increased in membranes prepared from the rat nucleus accumbens only after chronic DMI administration. Scatchard analysis of the binding data from the nucleus accumbens showed that [125I]Tyr11-somatostatin labels a single population of somatostatin binding sites with an affinity constant, Kd, of 1.8 +/- 0.60 nM and a Bmax of 330 +/- 90 fmol/mg protein. Chronic treatment with DMI increased the Bmax (500 +/- 140 fmol/mg protein) but had no effect on the Kd. This finding shows a regional effect of DMI on [125I]Tyr11-somatostatin binding sites in rat brain and suggests that somatostatin may play a role in the pathophysiology of depression.


Adulticidal effect of cyfluthrin against mosquitos of public health importance in Malaysia.

The efficacy of two formulations, wettable powder and emulsifiable concentrate, of cyfluthrin sprayed on plywood [10 mg (ai)/m2] was assessed against six species of mosquitos. The bioassay followed the WHO standard method, with some modification for the bioassay of insecticidal deposits on wall surfaces. The results indicated that these two formulations of cyfluthrin were effective against Anopheles dirus and Mansonia uniformis, moderately toxic to Aedes aegypti and Ae. albopictus in decreasing mortality through out the study period. It was least effective against Culex quinquefasciatus and An. maculatus, respectively. There was no statistically significant difference between these two formulations.


Effectiveness of slow release formulations of fenthion (Baytex) in the control of Mansonia breeding in polluted pond habitats.

Effectiveness of two types of granular formulations of fenthion (Baytex) was evaluated in controlling the breeding of Mansonia mosquitos in polluted pond habitats. Calcium carbonate and sand granular formulations, when applied at 2.50 g/m2 surface area with an average depth of 0.5 m were found to be effective in keeping the habitats completely free from Mansonia breeding for 14 days and 18 days respectively. Release of insecticide was slow and the effective duration of control after a single application was relatively longer in the sand formulation when compared to the calcium carbonate formulation. Single application of calcium carbonate and sand granular formulations of fenthion could effectively prevent Mansonia adult emergence for 23 and 30 days, respectively in polluted pond habitats, without causing any adverse effect on non-target insects.


HTLV-I antibody study in normal individuals and unselected hospital patients in Malaysia.

A serological investigation for human T cell leukemia virus I (HTLV-I) infection was carried out at the University Hospital, Kuala Lumpur. A total of 626 sera from a non-patient population and 1,038 sera from unselected in-patients were screened for HTLV-I antibodies using an enzyme-linked immunosorbent assay (ELISA). 27/1664 (1.6%) were found to be reactive. However, on Western blotting, only 2 sera were confirmed positive, both showing reactions for the major core (p19 and p24) and the envelope (gp46) proteins. Both of the serum samples were from unselected hospital patients. Most of the remaining sera which were reactive on screening showed indeterminate results on Western blotting. These were further tested by radioimmunoprecipitation assay (RIPA) and none of these sera gave a positive reaction. Therefore, only 2/1038 (0.19%) unselected patients could be confirmed to have antibodies to HTLV-I. None of the normal individuals screened showed a positive Western blot result. Our data indicate that HTLV-I infection is present in our population, but at a low prevalence rate.


[The use of emakor in arterial ischemia of the lower extremities in outpatient practice].

Overall 43 outpatients with arterial ischemia of the lower limbs were treated by emakor, a new Soviet drug that exerts a concomitant alpha- and beta-blocking action. The treatment resulted in a remarkable positive effect which manifested itself in amelioration of circulation in the lower limbs, positive time-course of changes in peripheral hemodynamics and in computer-aided tomography data. The use of emakor is contraindicated in exacerbation of gastrointestinal diseases, chronic pulmonary diseases associated with the obstructive syndrome, and marked signs of venous outflow obstruction in the lower limbs.


alpha-Conotoxin GI produces tetanic fade at the rat neuromuscular junction.

The ability of the marine snail toxin, alpha-conotoxin GI, to produce blockade of singly evoked twitches and to produce tetanic and train-of-four fade has been determined in the isolated rat hemidiaphragm preparation. Results were compared to those obtained with a reversible (vecuronium) and an irreversible (alpha-bungarotoxin) nicotinic acetylcholine antagonist and have been interpreted in terms of relative effects on post- and prejunctional nicotinic acetylcholine receptors at the neuromuscular junction. alpha-Conotoxin GI (0.5-2 microM) produced a concentration-dependent, readily reversible, decrease in the peak amplitude of single twitches and 50 Hz tetani, and an increase in tetanic and train-of-four fade. alpha-Conotoxin GI was consistently 2-3-fold more potent than vecuronium with respect to all of the measured tension parameters. Both alpha-conotoxin GI and vecuronium were approximately 2-fold more potent in producing tetanic fade and in blocking tetanic contractions than in blocking single twitches. In contrast to both alpha-conotoxin GI and vecuronium, alpha-bungarotoxin (0.13 microM) reduced the peak amplitude of both single twitches and 50 Hz tetani to the same extent without the appearance of a large degree of tetanic or train-of-four fade. Based on a comparison of the in vitro time course of neuromuscular block and of the relative effects of vecuronium, alpha-conotoxin GI and alpha-bungarotoxin on twitches, tetani and trains-of-four, we conclude that alpha-conotoxin GI has both pre- and postjunctional activity at the neuromuscular junction. In this respect, alpha-conotoxin GI resembles the clinically used competitive neuromuscular blocking drugs rather than the irreversible snake alpha-neurotoxins.


Different assays for HER-2/neu evaluation in breast cancer.

To evaluate different methodologic approaches for HER-2/neu analysis, we performed Southern, Northern, Western blot and histochemical assay on 112 samples from 86 primary tumors and 26 synchronous axillary metastatic lymph nodes of patients affected by operable breast cancer. Simultaneous statistical analysis of data obtained with the four methods (31 samples) showed that Western blot detected a higher percentage of alterations than the other assays (Cochran and Victor tests, 0.01 less than p less than 0.05). The same result was emphasized by pair analysis (McNemar, p less than 0.05), which evaluated the assay data two by two. Immunohistochemical evaluations were more in accord with immunoprecipitation data when performed on frozen or Bouin-fixed, paraffin-embedded tissues than on formalin-fixed, paraffin-embedded tissues.


Laparoscopy for evaluation of cryptorchid testis.

Four male patients with a unilateral nonpalpable testis were considered for laparoscopy. Preoperative evaluation by computerized tomography and ultrasonography failed to demonstrate cryptorchid testis. Laparoscopy clearly identified the anatomy in all 4 cases. Two patients had an absent testis, 1 patient underwent orchiectomy for a dysmorphic testis, and 1 patients underwent orchiopexy for a testis located within the inguinal canal. Pediatric laparoscopy is an effective and safe adjunct in the management of cryptorchid testis.


[Changes in the biochemical composition of the cerebrospinal fluid in acute carbophos poisoning].

As far as the pathogenesis of poisonings with organophosphorus pesticides is concerned, in addition to irreversible inhibition of acetylcholinesterase (AGE) in tissues, of importance are changes in the other systems which essentially determine the outcome of intoxication. The purpose of the present study was to examine the nature of changes occurring in total protein and protein fractions, free amino acids (aspartic and glutamic acids, glycine, isoleucine, leucine) and in certain enzymes (AST, ALT, CP, GGTP, GDH) in the cerebrospinal fluid (CSF) of patients with acute Malathion insecticide poisoning. 137 patients aged 20 to 50 years were placed under observation. There were 77 men and 60 women. 40 persons had poisoning of medium gravity and 97 were severely poisoned. The intake of the CSF was performed on days 1, 3, 10, 14 and 21 since the disease onset. It has been established that in acute Malathion insecticide poisoning, the CSF content of the stimulating mediator amino acids, aspartic and glutamic, rises within the early periods, whereas the concentration of the inhibitory mediator glycine decreases. The changes in protein fractions of the CSF are characterized by a fall of the content of globulins and a rise of albumins, thus attesting to the predominance of pathological processes in the brain, especially in the initial period of intoxication, and to the impairment of the blood-brain barrier. The development of intoxication is associated with activation in the CSF of LDN, CP, GGTP and GDH as well as by activation of LDH isozymes which is viewed as the result of the membranotoxic effect of a Malathion insecticide.


[Effects of carnitine and cobamamide on the dynamics of mental work capacity in patients with anorexia nervosa].

The authors relate the results of studying intellectual work fitness in patients with anorexia nervosa (in the stage of cachexia) receiving the vitamin-like drugs carnitine and cobamamide. It has been shown that the long-term food deprivation leads to a reduction of intellectual work fitness, lability of productivity, fluctuations in the work quality, appearance of latent fatigue. In spite of the fact that standard nonspecific treatment ameliorates intellectual work fitness, it does not lead to its normalization. The use of carnitine and cobamamide in the course of nonspecific treatment results in the reduction of the time spent on task implementation, a rise of the work rate as compared to the control group. However, this does not fully remove latent fatigue and does not bring about complete recovery to normal of intellectual work fitness. The combined use of carnitine and cobamamide eliminates fluctuations in the work rate and normalizes the scope and productivity of intellectual work.


[The mechanism of the intranasal action of dermorphin in representatives of 2 classes of vertebrates].

It has been shown that endogenous opioid dermorphin induces effective analgesia after intranasal injection to fish (0.02-0.20 mg/kg) and rats (0.005 mg/kg). Maintenance of dermorphin analgesia after olfactory and trigeminal denervation indicates that the analgetic effect is not realized via the olfactory receptors or free terminals of the trigeminal nerve.


[Epidemiological study of HIV seroprevalence in a leprosy patient population in Senegal].

We report the findings of an epidemiological study conducted between June 1989 and February 1990 on a population of leprosy patients in southern Senegal (Bignona major endemic disease sector). Two types of population were studied: patients living in urban areas and inmates of leprosaria. The global HIV seroprevalence (HIV 2 in all cases) of the leprosy-patient population was 1.15% (3/257): 0.8% (1/130) for the urban group and 1.5% (2/127) for the leprosaria. The seroprevalence rate does not differ significantly from that for the control group studied and for blood donors (1/221). The diagnosis of leprosy in the seropositive subjects had been established before 1980. None of them showed any sign of relapse. The immunodepression associated with the presence of HIV was only moderate: it was reflected in a lowering of the CD4 count and of the CD4/CD8 ratio, but with no clinical sign of AIDS.


[A case of testicular tumor arising in the undescended testis].

A 42-year-old man with testicular tumor arising in the left undescended testis is reported. The patient had bilateral cryptorchidism and was admitted to our clinic on March 20, 1989, complaining of a mass in the lower abdomen. Colography indicated complete obstruction at the sigmoid colon, and computed tomography showed a larger mass in the lower abdomen and paraaortic lymph node swelling, as well as left hydronephrosis. We suspected that a testicular tumor had arisen in the undescended testis, and ileus was caused by the tumor mass. Since the patient was in a poor condition from preexisting ileus, chemotherapy consisting of cisplatin, bleomycin and vinblastine (PVB regimen) was immediately started without confirming the histology. After two courses of PVB regimen, bilateral orchiectomy, retroperitoneal lymphadenectomy, and left nephrectomy were performed. Pathological examination of the testis and resected lymph nodes revealed no residual tumor cells, and we could not identify the original histology. Additionally, two courses of chemotherapy were performed after surgery. The patient is well without evidence of disease one year and ten months after surgery.


Liver biochemical tests and dengue fever.

The impact of dengue on liver function was studied by biochemical tests on 125 male and 145 female patients diagnosed with this disease during an outbreak that extended from November 1987 to December 1988. Abnormal levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase (G-GT) were observed in 93.3%, 82.2%, 7.2%, 16.3% and 83.0% of the patients, respectively. The elevation of transaminases was mild to moderate in most cases, but was 10-fold greater than the normal upper limit for AST and ALT in 11.1% and 7.4% of the patients, respectively. Initially, the level of AST was greater than that of ALT, increasing to maximum levels nine days after the onset of symptoms, then decreasing to normal levels within two weeks. Results of the biochemical tests did not differ significantly between the cases with and without hepatitis B or hepatitis C virus infection, but significantly higher elevations of AST, ALT, and G-GT were observed in patients with episodes of bleeding. Liver biopsies of two patients showed features of lobular hepatitis. Of the five fatal cases, three died of hepatic failure. It is concluded that dengue fever may cause hepatic injury and transaminase elevation similar to that in patients with conventional viral hepatitis. In epidemic or endemic areas, dengue fever infection should be considered in the differential diagnosis of hepatitis.


Simulated assembly line performance following ingestion of cetirizine or hydroxyzine.

Twelve healthy subjects participated in three daytime work periods, in a double-blind repeated measures Latin square design. Subjects received cetirizine (10 mg), hydroxyzine (25 mg), or placebo at 0800. Performance was measured each day during eight 50-minute test periods on a simulated assembly line task between 0830 and 1700. Before entry into the study, subjects were trained to a minimum 80% correction rate on the performance task. Performance decrements were consistently associated with hydroxyzine but not with cetirizine. Subjects made fewer correct responses with hydroxyzine compared with both cetirizine and placebo. Subjectively, participants reported feeling sleepier and performing worse during the hydroxyzine condition than following placebo. Cetirizine, however, did not differ from the other two conditions on self-assessments of alertness or performance. These findings support the hypothesis that objective measures of human functioning are more specific than are subjective measures.


Pharmacologic evaluation of factor XIIIa*-like enzyme activity in equine plasma as a potential therapeutic avenue for the inhibition of fibrinous tissue.

Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, XIIIa*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate. Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency), solubility of transparent fibrin gels in concentrated urea solution, in conjunction with simultaneous depletion of native fibrinogen fractions, and production of fibrin monomer. Compounds acting primarily as anticoagulants were recognized by lack of plasma gel formation, but retaining high spectrophotometric transmittance and no detectable depletion of native fibrinogen fractions. Compounds failing to inhibit either thrombin-mediated fibrinogen-fibrin transformation (ie, coagulation) or coagulation factor-XIIIa*-like enzyme activity were recognized by opaque plasma gels caused by fibrin polymerization, low spectrophotometric transmittance values, and coinciding with depletion of native fibrinogen fractions. Pharmaceuticals capable of exerting selective inhibition of coagulation factor-XIIIa*-like enzyme activity were further classified as competitive inhibitors of phase 1 (carbamide) or phase 2 (terminal amine) of the transglutamination process.


[Salazosulfapyridine in rheumatoid arthritis. A study of 49 patients].

The results of an open retrospective study of 49 patients treated with salazosulfapyridine (SASP) (sulphasalazine) for rheumatoid arthritis (RA) are reported. The patients, 7 men and 42 women, had a mean age of 53 years, and their mean duration of evolution of RA was 13.3 years. Sixty percent of them had undergone more than 3 previous disease-modifying drugs. The mean length of SASP treatment was 15.3 months. The initial response was favorable in 34 patients (69%). Treatment was ineffective and stopped in 12 cases (24.5%); the inefficacy was primary in 6 and tachyphylactic in the other 6. Twenty patients (41%) experienced at least one side effect. SASP was stopped in 11 patients (20.4%) due to undesirable side effects; 9 of the 11 times were during the first 2 months of treatment. Digestive system intolerance was the most common but led to drug withdrawal in less than half the patients. In all cases, mucocutaneous, neurosensory, hematological and hepatic side effects regressed during the month following SASP withdrawal. The therapeutic maintenance level was 67% at 1 year, 60% at 18 months, 52% at 2 years and 45% at 3 years. SASP has a role in the treatment of relatively slightly evolved forms of RA, before prescribing methotrexate. The possibility of delayed intolerance reactions, notably hematological and hepatic, justify prolonged biological monitoring of these patients.


Cystic fibrosis gene mutations and linked RFLPs in the Slovenian population.

The authors used polymerase chain reaction to analyse 56 Slovenian cystic fibrosis (CF) chromosomes for the presence of delta F508 and eight other most frequent mutations located in exons 7,11 and 20 (R347P, R334W, G551D, R553X, S549RA, S549RT, S549I and S1255X) of the CF gene. We also determined the frequency of haplotypes associated with CF for six linked RFLP markers (MetD/TaqI, MetH/TaqI, XV-2c/TaqI, KM-19/PstI, MP6d9/MspI and J3.11/MspI) in 27 Slovenian CF families. delta F508 mutation was present in 55.4 percent of the CF chromosomes. No case of the other mutations were detected in the sample of tested CF chromosomes. A very high degree of association (0.88) has been found between DNA marker MetH and CF (as measured by the Yule's association coefficient) in our population. Using the RFLP markers XV-2c and KM-19, we found that 85% of delta F508 mutated chromosomes have a single 1 2 (B) haplotype, and that this haplotype is present on only 15.4 percent of CF chromosomes without this deletion.


Short- and long-term effects of insulin on tyrosine aminotransferase gene expression.

In the present study the relationship between changes in tyrosine aminotransferase (TAT) enzyme activity, cytoplasmic mRNA levels, and gene transcription in response to both short- and long-term exposure to insulin was investigated. Insulin acutely inhibited transcription of the TAT gene by 50% in serum-deprived rat H4 hepatoma cells. Following this initial 50% decrease in transcription, there was a 2.5-fold induction in TAT activity that could not be accounted for by a concomitant increase in TAT mRNA levels. Insulin had no effect on the half-life of TAT mRNA. Insulin exposure for short periods of time also inhibited the glucocorticoid- and cAMP-induced transcription of the TAT gene. Like insulin, protein synthesis inhibitors acutely inhibited basal and glucocorticoid-induced TAT transcription. TAT activity gradually returned toward basal levels after 8 h of insulin treatment. A second insulin-induced increase in TAT activity (3.5-fold above basal levels) was observed by 24 h of insulin treatment. This second phase of insulin-induced TAT activity was associated with elevated levels of TAT transcription and TAT mRNA levels, and therefore, unlike the earlier stimulation, could be accounted for by changes in gene expression. Thus, the insulin-mediated regulation of the TAT gene in H4 cells is complex. Different transcriptional and post-transcriptional mechanisms are likely to be involved in the biphasic responses to insulin.


Heterogeneity of feline herpesvirus type 1 strains.

Heterogeneity of 9 feline herpesvirus type 1 (FHV-1) strains consisting of the prototype C27 strain, one French isolate, six Japanese isolates, and the attenuated vaccine F2 strain was examined by biological, immunological, and molecular biological methods. No significant difference was observed in virus growth and antigenic properties among the strains in Crandell feline kidney cell cultures. Hemagglutination activity was also detected in all extracts of cells infected with each strain. However, in immunoblot analysis, a virus-structural immunogenic protein with an M(r) of 36 kDa was lacking in 2 strains, one of which was the vaccine F2 strain, whereas the other immunogenic proteins including three kinds of major glycoproteins were detected in all strains without differences in electrophoretic mobilities. Furthermore, when restriction endonuclease analysis was performed to examine the genomic heterogeneity of strains, the cleavage patterns with the enzyme MluI showed a genomic heterogeneity between wild and vaccine strains. In contrast, only a slight variation in the sizes of some fragments was shown with most of the 7 other enzymes used. These results indicated that the lack of the 36 kDa protein and the MluI cleavage pattern could be used as markers of the vaccine F2 strain. The specific markers are important not only to control the quality of the vaccine but also to evaluate the vaccine immunity in FHV-1 infection in cats.


Infectivity and pathogenesis of iridescent virus type 22 in various insect hosts.

This paper reports the results of a series of laboratory experiments to determine the infectivity and pathogenesis of iridescent virus type 22 (IV 22) for six species of mosquitoes, phlebotomine sand flies and triatomid bugs. Following inoculation, IV 22 replicated in all of the species tested, without producing noticeable mortality within a 14 day observation period. Examination of the infected insects by immunofluorescence demonstrated large amounts of viral antigen in many different organs. Electron microscopy done on infected mosquitoes (Aedes aegypti) showed large numbers of virus particles within cells of the fat body, muscle tracheal and midgut epithelium. Virus replication in the mosquitoes was confirmed to host cell cytoplasm and was similar to that described in the natural blackfly (Simulium) host. Transovarial transmission of IV 22 could not be demonstrated in A. aegypti, and only a small percentage of mosquito larvae could be infected orally. Results of these experiments are compatible with observations of other iridescent viruses; IV 22 is highly infectious for a wide range of insects when introduced into their hemolymph, but it is not very infectious per os. These characteristics would appear to limit its value as a potential biocontrol agent for Diptera.


[Apud cells in endometrial cancer].

55 endometrial carcinomas containing apud cells are studied. Correlation between the endocrine-metabolic disturbances and mitotic index, on the one hand, and number of apud cells and their product on the other, is revealed. If the percentage of apud cells is above 20 of all parenchymal cells, low mitotic index in the tumour, marked production of serotonin, calcitonin and other hormones and high incidence of endocrine disturbances together with a relatively favourable prognosis are observed. Low number of apud cells associated with high mitotic index and high incidence of unfavourable outcomes while the hormone production and endocrine disturbances were rare or absent.


[Histogenesis of experimental renal tumors in mice].

Epithelial kidney tumours induced in CBA male mice by 1,2-dimethylhydrazine were studied histochemically and immunohistochemically. Histologically, 48 tumours studied were diagnosed as clear-cell, acidophilic or mixed adenomas located in the renal cortex. Gamma-glutamyl transpeptidase (GGT) was strongly positive in normal proximal convoluted tubules, slightly positive in the cells of Bowman capsule and negative in 47 of 48 tumours examined. Antibodies against the new antigen obtained from the mouse liver oval cells and called A6 antigen were also used. This antigen in normal kidney is negative in proximal tubules but always positive in distal tubules and collective ducts. It was also positive in all 47 GGT-negative tumours. One tumour was GGT-positive and A6 antigen-negative. The conclusion is made that the majority of renal cell adenomas in mice most likely originate from the collective duct system and not from the proximal tubules.


The pathogenesis of Tourette's syndrome. A possible role for hormonal and excitatory neurotransmitter influences in brain development.

Tourette's syndrome (TS) is associated with prominent gender differences in clinical expression, tics with a sexual content, and a stabilization or improvement of symptoms after puberty. It is herein hypothesized that some tics can be viewed as inappropriately expressed (normally inhibited) fragments of primitive motor and vocal programs involved in reproductive activity. The brain regions involved in TS (basal ganglia and limbic system) are proposed to be counterparts in humans of those functioning in primitive reproductive behavior whose development and organization are under sex hormone control. It is further hypothesized that sex hormone action is mediated by excitatory neurotransmitter mechanisms such that an excessive trophic effect occurs early in development and a neurotoxic environment emerges later on. The defective gene in TS is hypothesized to influence these developmental processes. This hypothesis has implications for the investigation of the pathogenesis of TS and for experimental therapeutics of the disorder.


[Effects of dietary proteins on analgesic activity of tolerance and physical dependence on morphine in rats].

Effects of dietary proteins such as casein and egg albumin on analgesic activity of, tolerance to and physical dependence on morphine in rats were examined. There was no difference in analgesic activity after acute administration of morphine 10 mg/kg, s.c. between rats treated with casein food or egg albumin food and normal food for 5 or 21 days. The development of tolerance to morphine analgesia in rats treated with albumin food but not with casein food was suppressed during daily morphine 10 mg/kg, s.c. on 5 consecutive days. Rats were treated with casein or albumin food mixed with morphine (0.5 mg/g of food) for 5 days. Morphine intake in rats treated with albumin food was significantly decreased as compared to that with morphine admixed casein or normal food. Body weight loss by naloxone in morphine-dependent rats was significantly less in both casein food and albumin food groups than in the normal food group. These results suggest that chronic dietary treatment with albumin may produce a partial inhibition of development of tolerance to morphine analgesia and that with casein may attenuate morphine withdrawal manifestation in rats.


Alcohol-preferring rats have fewer dopamine D2 receptors in the limbic system.

Dopamine D2 receptors in nucleus accumbens, olfactory tubercle and caudate nucleus of Sardinian ethanol-preferring (SP), and non-preferring (SNP) rats were compared by using [3H]YM-09151-2 binding. SP rats exhibited, in each area, lower density of D2 receptors than SNP and unselected Wistar (UW) rats. The results suggest that reduction in D2 receptors in SP rats may be relevant to their innate preference for alcohol.


The effects of MDMA and other methylenedioxy-substituted phenylalkylamines on the structure of rat locomotor activity.

The effects of acute subcutaneous injections of methylenedioxy-substituted phenylalkylamines in rats were tested in an unconditioned motor behavior paradigm using the Behavioral Pattern Monitor (BPM). Based on a previously developed scaling hypothesis and the associated temporal and spatial scaling exponents (alpha and d), the effects of racemic and S(+) 3,4-methylenedioxyamphetamine (MDA), racemic, S(+) and R(-) 3,4-methylenedioxymethamphetamine (MDMA), racemic N-methyl-1-(1,3-benzodioxol-5yl)-2-butanamine (MBDB), racemic N-ethyl-3,4-methylenedioxyamphetamine (MDEA), 2,5-dimethoxy-4-iodoamphetamine, and methamphetamine were characterized using the d-alpha plane. Three distinct dose-response patterns were observed. 1) S(+) and (+/-)MDA had pronounced dose-dependent effects on the structure of motor behavior, which were characterized by long-straight path movements and minimal changes in the amount of motor behavior. 2) (+/-)MDMA and (+/-)MBDB dose-dependently changed patterns of movements towards long-straight paths together with dose-dependent increases in the amount of motor activity. 3) S(+)MDMA and (+/-)MDEA produced dose-related increases in the amount of motor activity with minimal changes of the movement patterns in the BPM. Comparisons with the existing drug discrimination, operant, and biochemical literature on these compounds lead to the conclusion that the observed effects in the d-alpha plane do not simply reflect the different effects of these compounds as dopamine or serotonin (5-HT) releasers or reuptake inhibitors and do not parallel their different abilities to exhibit hallucinogen-like effects. Instead, indirect 5-HT1 effects appear to contribute substantially to the differential changes in the amount and structure of motor behavior induced by the phenylalkylamines. This conclusion may provide an encouraging rationale to develop postsynaptically effective "entactogens," a potential new drug category as adjunctive psychotherapeutics.


Histopathologic changes of the spleen in suckling rats inoculated with Hantaan virus.

The purpose of this study is to delineate the histopathologic findings of the spleen after Hantaan viral inoculation, which is the largest lymphoid organ in rats, and to identify the viral location by anti-Hantaan virus (HTNV) monoclonal antibody. All the sixty one suckling rats of less than twenty four hours of age were used. Except twenty one rats of control group, twenty-five rats inoculated intracerebrally for the early change and fifteen suckling rats inoculated intramuscularly for the late change were uniformly susceptible to lethal infection with the ROK 84-105-1 strain of seed HTNV. The characteristic histopathologic findings were; appearance of macrophages below the splenic capsule on the 3rd day, small lymphocytes around the periarteriolar sheath on the 5th day increasing in numbers on the 7th day, and a markedly expanded marginal zone with some immunoblasts and plasma cells as well as decreased extramedullary hematopoiesis on the 9th and 14th days. Time of onset of histopathologic changes in spleen thickness, appearance of medium and large lymphocytes and degree of extramedullary hematopoiesis were influenced by inoculation route, whereas expansion of the marginal zone was affected by postnatal age.


Effects of the beta-adrenergic agonist, ritodrine, and insulin on plasma potassium concentrations in fetal lambs.

Prolonged infusion of the beta 2-adrenergic agonist, ritodrine, into sheep during late pregnancy decreased maternal plasma K+ from 3.6 to 2.5 mmol l-1 during the first 6-8 h of infusion, as it does during tocolysis in women. This decrease was not accompanied by significant change in fetal plasma K+ concentration. Ritodrine infusion (1-3.5 micrograms kg-1 min-1) directly into the fetus also did not decrease fetal plasma K+ significantly. In contrast, insulin (2.5 mU kg-1 min-1), infused together with glucose (3.6 mg kg-1 min-1) directly into the fetus decreased fetal plasma K+ concentration by 0.8 mmol l-1 within 1 h. The results suggest immaturity in beta 2-adrenergic receptor regulation of electrogenic K+ uptake by muscle in fetal lambs.


The effect of luminal flow in rabbit carotid artery on transmural fluid transport.

The steady-state flow of fluid across the wall of the isolated rabbit common carotid artery has been measured in the presence and absence of flow within the lumen of the vessel. The perfusate solution contained either 10 or 40 mg ml-1 albumin and transmural flux was measured by monitoring the rate of movement of fluid into a chamber enclosing the artery. Vasomotion was minimized by the inclusion of the vasodilator sodium nitrite in both the perfusate and the outer bathing solution. A relatively slow luminal flow caused a reversible increase in the transmural flux by 20-30% relative to the value in the absence of flow. The mechanism responsible for the increase is not clear, but since it was not affected by the H1 antagonist, mepyramine, it would not appear to have been mediated by histamine release.


Enhanced electrogenic secretion in vitro by small intestine from glucagon-treated rats: implications for the diarrhoea of starvation.

Glucagon treatment of fed rats (50 micrograms I.P. every 6 h for 3 days) induces significant increases in vitro of the basal short-circuit currents of the jejunum (52%) and proximal ileum (81%) and in their electrogenic secretory responses to stimulation by bethanechol, a muscarinic agonist. The results support a role for glucagon in the intestinal hypersecretion observed in starvation and nutrient deprivation.


Renal tubular enzyme effects of clarithromycin in comparison with gentamicin and placebo in volunteers.

This study assessed the potential nephrotoxicity of clarithromycin in comparison with gentamicin and placebo. Increased urinary excretion of alanine aminopeptidase (AAP) and N-acetyl-beta-D-glucosaminidase (NAG) served as markers of renal tubular injury. The study utilised a multiple-dose, double-blind, randomised, parallel group design. 14 healthy male subjects received 1 of 3 treatment regimens: (a) clarithromycin 500 mg orally every 12h for 13 doses and intravenous placebo every 8h (n = 5); (b) oral placebo every 12h and intravenous placebo every 8h (n = 4); and (c) intravenous gentamicin 1.7 mg/kg every 8h for 19 doses and oral placebo every 12h (n = 5). 24h urine collections were obtained daily for determinations of AAP and NAG activities. Gentamicin produced statistically significant increases (p less than 0.0001) in AAP and NAG excretion, with increases as early as the first and second day of dosing. Clarithromycin, when compared with placebo, did not produce significant elevations in AAP or NAG activity. On the basis of these data, it is unlikely that usual doses of clarithromycin have significant potential for causing nephrotoxicity.


Roles of PKA and PKC in facilitation of evoked and spontaneous transmitter release at depressed and nondepressed synapses in Aplysia sensory neurons.

Two second messenger pathways, one that uses the cAMP-dependent protein kinase A (PKA), the other that uses protein kinase C (PKC), have been found to contribute to the short-term presynaptic facilitation of the connections between the sensory neurons in Aplysia and their target cells, the interneurons and motor neurons of the gill-withdrawal reflex. To study their relative contributions as a function of the previous history of the neuron's activity, we have examined the effects of inhibiting PKA (using Rp-cAMPS) and PKC (using H7) on the short-term facilitation of spontaneous release as well as of the evoked release induced by serotonin at nondepressed, partially depressed, and highly depressed synapses. Our results suggest that whereas activation of PKA is sufficient to trigger the facilitation of nondepressed synapses, activation of both PKA and PKC is required to facilitate depressed synapses, with the contribution of PKC becoming progressively more important as synaptic transmission becomes more depressed.


[Restriction fragment length polymorphisms of chloroplast DNA and the intergenic spacer of rRNA gene in cultivated barley of China].

A sample of 80 accessions collected from several major barley growing areas in China was assayed for restriction fragment length polymorphisms at two regions of the chloroplast DNA and the intergenic spacer of the ribosomal RNA gene (rDNA). The results showed that the spacer length was highly polymorphic and 8 spacer length variants constituting 8 phenotypes were observed in this sample. It is also clear that the spacer length variants and the phenotypes were differentially distributed in different geographical regions, probably due to adaptation of the genotypes to the local environments. We did not detect variation in the two chloroplast fragments, indicating that the variability of chloroplast DNA is low in cultivated barley.


Signalling in human tumour infiltrating lymphocytes: the CD28 molecule is functional and is physically associated with the CD45R0 molecule.

The CD28 T cell activation pathway was functional in human tumour infiltrating lymphocytes (TIL) and can induce strong proliferation, lymphokine release and calcium mobilisation. Conversely, TIL responded poorly to stimulation via CD2, and CD28 did not synergise with CD2, which is at variance with that observed using peripheral lymphocytes from the same patients. On stimulation with anti-CD28 the monoclonal antibody, most TILs, which were CD3+, CD28+ and CD45R0+ at the beginning of culture, co-expressed both high (CD45RA) and low (CD45R0) molecular weight isoforms of CD45. CD28 was associated with the CD45R0 isoform at the cell surface of activated TIL, as demonstrated by immunoprecipitation and immunoenzymatic assay. Thus CD28 can substitute for CD3 in TIL leading to the expansion of functional lymphocytes and to the amplification of antitumour immune response.


Direct effects of tamoxifen on growth hormone secretion by pituitary cells in vitro.

There is now strong evidence to suggest that insulin-like growth factor I (IGF-I) plays an important role in breast cancer proliferation. Recently we observed that tamoxifen-treated stage I breast cancer patients have serum IGF-I levels significantly lower than placebo-treated patients. Since IGF-I is growth hormone (GH) dependent, we have tested the hypothesis that tamoxifen alters serum IGF-I levels through direct inhibition of GH secretion. Immature lamb pituitary cultures were examined for acute (3 h) or chronic (1-6 day) effects of the drug, using doses (0.1-10 mumol/l) based on known steady state levels in patients on tamoxifen therapy (0.31-3.1 mumol/l). Tamoxifen had a direct, dose-related, inhibitory effect on GH release from pituitary somatotropes, during acute as well as chronic treatment. The 10 mumol/l dose consistently decreased both basal and growth hormone releasing factor stimulated GH release. These in vitro data are consistent with our hypothesis that tamoxifen suppresses serum IGF-I levels by acting at the pituitary to inhibit GH release.


Effects of alpha-adrenoceptor and of combined sympathetic and parasympathetic blockade on cardiac performance and vascular resistance.

1. Cardiac performance and vascular resistance was studied in seven healthy men by radionuclide cardiography and venous plethysmography before and after alpha-adrenoceptor blockade with phentolamine and after combined alpha-adrenoceptor, beta-adrenoceptor (propranolol) and parasympathetic (atropine) blockade. 2. During alpha-adrenoceptor blockade heart rate and cardiac output increased considerably and left ventricular ejection fraction increased because of increased contractility. Systemic vascular resistance fell both during alpha-adrenoceptor blockade alone and during combined blockade. The increase in calf blood flow was of the same magnitude after combined blockade and after alpha-adrenoceptor blockade alone, and was considerably higher than the fall in systemic vascular resistance. Plasma catecholamine concentrations increased after phentolamine, but the changes were blunted when propranolol and atropine were added. 3. These results indicate that peripheral vasoconstriction especially that exerted by alpha-adrenoceptor nervous tone in skeletal muscle restricts left ventricular emptying of the intact heart. During pharmacologic blockade of the sympathetic and parasympathetic nervous system at rest the chronotropic state is augmented, whereas preload and inotropy are unaffected.


The zebrafish homeobox gene hox[zf-114]: primary structure, expression pattern and evolutionary aspects.

It is gradually becoming accepted that vertebrate homeobox genes, like their counterparts in Drosophila, are crucial for normal development of the embryo. Most vertebrate homeoboxes reported so far are related to the Drosophila Antennapedia (Antp) sequence, and here we describe hox[zf-114], a novel Antp-like homeobox gene from the zebrafish. The sequence of the hox[zf-114] homeodomain indicates that this gene could be a member of a subfamily defined by the mouse Hox-1.5/-2.7/-4.1 genes. However, the evolutionary origin of hox[zf-114] is unclear and, based on the putative protein sequence, we conclude that it is not directly homologous to Hox-1.5, Hox-2.7 or Hox-4.1, or to other known mammalian homeobox genes. Nevertheless, as revealed by in situ hybridization, hox[zf-114] exhibits a spatial expression pattern typical for vertebrate Antp-like homeobox genes. Transcripts are detected in the posterior hindbrain, where a sharp anterior border of expression is observed, and throughout the spinal cord. The hox[zf-114] gene is also active in a region that gives rise to the pectoral fins. These findings suggest a role for hox[zf-114] in anteroposterior patterning of the neural tube and in pectoral fin development.


Pyroglutamyl [correction of Pyroglutamil] -peptidase I activity in the cortex of the cat brain during development.

Thyrotropin Releasing Hormone (TRH) is a principal regulator of thyroid system function. However, significant concentrations of TRH were found throughout the central nervous system, the cortex being one of the areas most richly endowed with thyroliberin. Research concerning the functional role of this brain peptide is performed, in part, by studying peptidase enzymes which may be involved in the inactivation of the peptide. The pGlu-His bond is cleaved by two pyroGlu-peptidases: I (soluble) and II (membrane-bound). In the present investigation, developmental activity of the soluble form is described in the cortices of the cat brain. The selected maturation stages were 15 and 30 days postnatal. The cortices were the frontal, parietal, area 17 and areas 18 and 19 as a whole, distinguishing brain hemispheres in all cases. PyroGlu-aminopeptidase I activity increased significantly with age in all the brain regions except area 17. It is suggested that this enzyme activity plays a part in the neurochemical changes that take place during brain maturation.


Successful peripheral blood stem cell autotransplantation in a child with advanced B-cell lymphoma.

A 2-year-old boy with B-cell lymphoma (stage IV) in the first complete remission received myeloablative treatment followed by peripheral blood stem cell autotransplantation and is surviving event-free for 18 months. Reconstitution of all cell lines occurred very rapidly, ie, a level of 1000 leukocytes per microliter was reached after 9 days, that of 500 granulocytes per microliter after 10 days, and platelets were substituted only once. This result suggests that PBSCT can be safely employed during consolidation therapy for malignant disorders because of its short duration of bone marrow suppression.


Conserved classes of homeodomains in Schistosoma mansoni, an early bilateral metazoan.

Genes containing a homeobox can be divided into classes based on the distinctive peptide sequences of their diverged homeodomains. Many of these classes, including Antennapedia, engrailed and paired, are strongly conserved in higher multicellular animals, but have not previously been found in platyhelminths, the flatworms which represent the most primitive bilateral metazoans. We have screened cDNA libraries of the platyhelminth Schistosoma mansoni using a degenerate oligonucleotide derived from the third helix of the homeodomain, and have identified numerous schistosome homeobox-containing sequences, including members of the Antennapedia, engrailed and paired classes. The schistosome homeodomain sequences are more similar to the higher animals sequences in their respective classes than they are to each other, indicating that the establishment of these three distinctive classes is at least as ancient as the flatworms. Our data suggest that the ancestral functions of the Antennapedia, engrailed and paired classes involve fundamental features of all bilateral metazoan development. The putative full-length coding sequence of the S. mansoni en homologue is presented.


Isolation and analysis of embryonic expression of Hox-4.9, a member of the murine labial-like gene family.

Two members of the murine labial (lab) subfamily of Antennapedia-like homeobox-containing genes, Hox-1.6 and Hox-2.9, have been identified previously. Here we describe a third member genetically linked to the Hox-4 cluster on chromosome 2. This gene, designated Hox-4.9, is similar in structure to the other lab subfamily members. However, little coding sequence other than the homeobox and sequences immediately upstream of it have been conserved. By in situ hybridization analysis, Hox-4.9 mRNA is first detected at the end of the late streak stage (E7.75) in presumptive lateral and extraembryonic mesoderm. During early neurogenesis (E8.0-8.5), Hox-4.9 is detected solely in lateral mesoderm; its lack of expression in somitic mesoderm and the neural tube makes it unique among the Hox genes. By late neurogenesis and through mid-gestation (E9.0-E11.5), Hox-4.9 is no longer detected in lateral mesoderm but is found instead in a restricted region of presumed trunk neural crest and in the dermatome. These data are discussed in comparison with what is known about expression of the other members of the lab subfamily.


Novel antitumor peptide hormones and their effect on signal transduction.

A series of novel gonadotropin releasing hormone (GnRH) and Somatostatin analogs have been developed in our laboratory and were screened for antiproliferative and signal transduction inhibitory effect. Our GnRH analog Folligen, had significant antitumor activity on DMBA induced mammary carcinomas in rats without blocking ovarian functions. The direct effect of Folligen and Buserelin has been compared on the human breast cancer cell line MDA-MB-231. Folligen was found to be more effective in inhibiting cell proliferation and significant differences were found in the signal transduction pathways activated by these analogs. Our novel Somatostatin analogs were screened for tyrosine kinase inhibition and for antiproliferative effect on human colon tumor cells and for growth hormone (GH) release inhibition in vitro and in vivo. The analog TT-2-50 was significantly more active inhibiting GH release in superfused rat pituitary cells and in vivo than native Somatostatin and it strongly inhibited tyrosine kinase and proliferation while it stimulated protein kinase C activity.


Prognostic factors in human primary breast cancer: comparison of c-myc and HER2/neu amplification.

Amplification of oncogenes in primary tumours may have prognostic and/or therapeutic significance for patients with breast cancer. We have studied HER2/neu and c-myc amplification together with steroid receptors in human primary breast tumours and related the outcome with (relapse-free) survival. A strong inverse correlation was found between HER2/neu amplification and the presence of oestrogen and progesterone receptors. Actuarial 5-years survival showed that breast cancer patients with c-myc amplification in their primary tumours experience a shorter relapse-free survival, especially in node-negative and in receptor-positive tumours, whereas HER2/neu amplification may be of prognostic value for overall survival in receptor-negative tumours. Overall, in our hands, c-myc amplification appeared to be a more potent prognosticator than HER2/neu amplification in human primary breast cancer.


Somatostatin receptor imaging in the diagnosis and treatment of neuroendocrine tumors.

Somatostatin analogs are used in the control of hormonal hypersecretion and tumor growth of patients with acromegaly, islet cell carcinomas and carcinoids. Recently we showed that somatostatin receptor positive tumors can be visualized in vivo after the administration of radioactive isotope-labelled somatostatin analogs. Receptor imaging was positive in 18/21 islet cell tumors, 30/31 carcinoids, 26/28 paragangliomas, 9/14 medullary thyroid carcinomas, 5/7 small cell lung cancers, 6/7 neuroblastomas, 38/49 primary breast cancers, and 0/18 pancreatic adenocarcinomas. Also 11/11 meningiomas, 4/4 astrocytomas and 0/3 glioblastomas could be visualized. Somatostatin receptor imaging is an easy, harmless and painless diagnostic method. It is an in vivo method for the recognition of neuroendocrine cancers. It localizes multiple and/or metastatic tumors, predicts the successful control of hormonal hypersecretion by octreotide and seems of prognostic value in certain types of cancer. This scintigraphic method might help in patient selection for clinical trials with somatostatin analogs in the treatment of neuroendocrine cancers.


Hormonal regulation of c-erbB-2 oncogene expression in breast cancer cells.

Expression of the c-erbB-2 (neu, HER-2) oncogene is found to be subjected to hormonal and developmental regulation in normal as well as neoplastic mammary cells. We have previously reported that estrogens inhibit c-erbB-2 expression at both the mRNA and protein level in estrogen receptor (ER)-positive, but not in ER-negative, breast cancer cell lines. Reversion of c-erbB-2 inhibition is seen with tamoxifen. The effect on c-erbB-2 expression of several other hormones and factors, which influence mammary cell growth and differentiation, has been studied. Our observations indicate that, in normal and neoplastic mammary cells, c-erbB-2 expression is inversely related to cell proliferation. While estrogens, anti-estrogens and cAMP clearly regulate c-erbB-2 mRNA levels, epidermal growth factor dramatically decreases the c-erbB-2 protein without affecting the level of c-erbB-2 mRNA. Therefore, different signals converging in terms of cell proliferation regulate c-erbB-2 expression by different molecular mechanisms.


The role of erbB-2 and its ligands in growth control of malignant breast epithelium.

The erbB-2 (HER-2, neu) protooncogene is overexpressed on the surface of about 25% of human breast cancers. It is homologous to epidermal growth factor receptor and a putative growth factor receptor. Overexpression in breast, ovarian and gastric cancers is associated with a worse prognosis. We have recently discovered two ligands for this receptor. They both induce receptor phosphorylation. At low concentrations both induce clonogenic growth of overexpressing cells; at higher concentrations both are growth inhibitory. Both can overcome the inhibitory effects of both monoclonal antibodies directed against the ligand binding site and soluble extracellular domain. These ligands may form an attractive basis for antitumor therapy.


Somatostatin receptors in human cancer: incidence, characteristics, functional correlates and clinical implications.

Somatostatin receptors (SS-R) have been identified in membrane homogenates or tissue sections from several hundred tumors. SS-R were found in most neuroendocrine tumors, i.e. GH and TSH producing pituitary tumors, endocrine gastroenteropancreatic (GEP) tumors, paragangliomas, pheochromocytomas, medullary thyroid carcinomas (MTC) and small cell lung carcinomas. SS-R were also expressed in a majority of malignant lymphomas, in several brain tumors (all meningiomas, most astrocytomas) and in breast tumors. The majority of tumors expressing SS-R are rather differentiated (i.e. astrocytomas vs glioblastomas), but exceptions exist (high grade malignant lymphomas). An inverse relationship exists between SS-R and receptors for epidermal growth factor (EGF-R) incidence in lung tumors, glial tumors and most breast tumors, whereas meningiomas express simultaneously both receptors. A minority of tumors (ovarian tumors, MTC, insulinomas) express a subtype of SS-R, characterized by low affinity for the octapeptide SS analog octreotide. The function mediated by SS-R in human tumors may differ according to the tumor type. SS-R in pituitary and GEP tumor mediate hormone secretion inhibition with, in addition, possibly some antiproliferative effects. In meningiomas, however, activation of SS-R inhibits forskolin-stimulated adenylate cyclase activity, and weakly stimulates proliferation. Whereas SS-R seem to mediate antiproliferative effects in animal models and cell lines of lymphomas, breast and lung tumors, such an effect has not yet been convincingly documented in human primary tumors. The clinical implications of the presence of SS-R in tumors are manyfold: (1) as a predictive marker for efficient therapy with octreotide in pituitary and GEP tumors; (2) as a diagnostic marker: for pathobiochemical classification of tumors, using in vitro detection methods; for clinical evaluation using in vivo scanning techniques; (3) as a prognostic marker; and (4) as a potential radiotherapeutic target.


Modulation of the agonist activity of antisteroids by a novel cis-acting element.

The amount of agonist activity displayed by the antiglucocorticoid dexamethasone mesylate (Dex-Mes) for the induction of tyrosine aminotransferase (TAT) in rat hepatoma cells is greater than for glutamine synthetase and varies over a period of weeks. This variation, which has been reproduced over a period of 40 h by changing the density of the cells, suggests the involvement of a trans-acting factor. The target of this proposed trans-acting factor has now been localized to the region between -3.9 to -2.9 of the rat TAT gene from experiments with cells that were stably transfected with hybrid TAT/CAT constructs. Deletion experiments with transiently transfected TAT/tk promoter/CAT constructs revealed that this entire activity could be conveyed by a 21 bp sequence of the TAT gene. Gel shift experiments support the binding of a factor(s) to this 21 bp sequence. Thus the activity of the antagonist Dex-Mes is relatively independent of steroid structure and is largely determined by the further interactions of a trans-acting factor with the cis-acting sequence. We call this novel sequence a glucocorticoid modulatory element. A model is advanced which accounts for almost all of the results concerning TAT induction by glucocorticoids. This same model may also be useful in explaining why the amount of agonist activity of most antisteroids varies, even for different genes within the same cell.


Signal transduction by the neu/erbB-2 receptor: a potential target for anti-tumor therapy.

The neu/erbB-2 protooncogene encodes a transmembrane tyrosine kinase homologous to receptors for polypeptide growth factors. The oncogenic potential of the presumed receptor is released through multiple genetic mechanisms including a point mutation, truncation of non-catalytic sequences and overexpression. The latter mechanism appears to be relevant to human cancers as elevated expression of the neu/erbB-2 gene is frequently observed in solid tumors of various adenocarcinomas. It is therefore conceivable that strategies aimed at the biochemical mechanism of action of the neu/erbB-2 tyrosine kinase may contribute to the treatment of certain human cancers. To this aim we undertook a multiple research approach consisting of the following directions: (i) The neu/erbB-2 ligand--a systematic screening of potential biological sources of the hypothetical hormone molecule, that presumably binds to the neu/erbB-2 protein, resulted in detection of a candidate activity in the medium of certain cultured transformed cells. Partial purification indicated that the factor is a 30-35 kDa glycoprotein. Further studies revealed several biochemical characteristics of the factor that may be helpful for complete purification and structural analysis of this novel hormone. (ii) Signal transduction by neu/erbB-2--using a chimeric receptor approach and various mutants we found that all the oncogenic forms of the neu/erbB-2 are constitutively coupled, both physically and functionally, to a multi-protein complex of signaling molecules. The latter includes the phosphatidylinositol-specific phospholipase C gamma and a phosphatidylinositol kinase. Thus, the metabolism of inositol lipids is probably a major biochemical pathway utilized by the neu/erbB-2 tyrosine kinase. (iii) Tumor inhibitory antibodies--we generated a panel of monoclonal antibodies to the presumed receptor. Surprisingly, some antibodies almost completely inhibited the growth of tumor cells in athymic mice, whereas one antibody significantly accelerated the rate of tumor growth in animals. Interestingly, the inhibitory antibodies conferred a mature phenotype to cultured breast cancer cells, implicating terminal differentiation in tumor retardation.


Role of the extracellular matrix in age-related modifications of the rat aorta. Ultrastructural, morphometric, and enzymatic evaluations.

Connective tissues such as blood vessels are known to be greatly affected by age because of impaired functional properties and increased susceptibility to diseases. With the aim of providing further information on the role of the extracellular matrix in age-related modifications, we investigated the aorta in the rat model from birth to senescence by means of morphological and morphometric observations and by evaluation of lysyl oxidase activity. Results focused on the dramatic vascular rearrangements due to progressive fibrosis of the extracellular matrix and on prominent elastin modifications. The presence of lysyl oxidase activity, even in the oldest animals, might be at least partly responsible for the increased stiffness of the aging extracellular matrix. The striking age-related remodeling of the aortic architecture and the alterations of the interactions between cellular and extracellular compartments might greatly influence the functional properties of the arterial wall in senescence, at least contributing to the consequences of some apparently age-related vascular disorders.


pH and kinetic isotope effects on the reductive half-reaction of D-amino acid oxidase.

Primary deuterium kinetic isotope and pH effects on the reduction of D-amino acid oxidase by amino acid substrates were determined using steady-state and rapid reaction methods. With D-serine as substrate, reduction of the enzyme-bound FAD requires that a group with a pKa value of 8.7 be unprotonated and that a group with a pKa value of 10.7 be protonated. The DV/Kser value of 4.5 is pH-independent, establishing that these pKa values are intrinsic. The limiting rate of reduction of the enzyme shows a kinetic isotope effect of 4.75, consistent with this as the intrinsic value. At high enzyme concentration (approximately 15 microM) at pH 9,D-serine is slightly sticky (k3/k2 = 0.8), consistent with a decrease in the rate of substrate dissociation. With D-alanine as substrate, the pKa values are perturbed to 8.1 and 11.5. The DV/Kala value increases from 1.3 at pH 9.5 to 5.1 at pH 4, establishing that D-alanine is sticky with a forward commitment of approximately 10. The effect of pH on the DV/Kala value is consistent with a model in which exchange with solvent of the proton from the group with pKa 8.7 is hindered and is catalyzed by H2O and OH- above pH 7 and by H3O+ and H2O below pH 7. With glycine, the pH optimum is shifted to a more basic value, 10.3. The DV/Kgly value increases from 1.26 at pH 6.5 to 3.1 at pH 10.7, consistent with fully reversible CH bond cleavage followed by a pH-dependent step. At pH 10.5, the kinetic isotope effect on the limiting rate of reduction is 3.4.


Cells induced to express a human immunodeficiency virus type 1 envelope gene mutant inhibit the spread of wild-type virus.

The feasibility of using a trans-dominant interfering human immunodeficiency virus type 1 (HIV-1) envelope mutant for inducible gene therapy of HIV infection was investigated. Genes encoding wild-type or mutant glycoproteins were introduced into CD4+ cells, where they were stably maintained but not expressed until induced. Envelope (env) gene expression was dependent upon the viral regulatory protein Tat. Induction of the mutant env resulted in resistance to cytopathic effects mediated by wild-type envelope and decreased infectious vector virus production. When cells containing the mutant env gene were infected with wild-type virus, viral spread was inhibited. The fact that maintenance of the env gene was stable over time suggests that inducible gene therapy using the dominantly interfering env mutant may be a feasible approach to slowing the progression of HIV-1 disease.


Variations of plasma creatine kinase in rabbits following repetitive blood sampling effects of pretreatment with acepromazine, carazolol and dantrolene.

Plasma creatine kinase activity increased significantly (P less than 0.001) in rabbits sampled every two hours for 12 hours (mean from 509 to 2242 U/l), but did not change when rabbits had been accustomed to laboratory handling procedures for two weeks. This increase was not alleviated or only moderately by pretreatment with acepromazine (per os, 2.5 mg.kg-1), carazolol (intravenously, 0.05 mg.kg-1) or dantrolene (intravenously, 1.0 mg.kg-1). Thus, when using plasma creatine kinase in rabbits, e.g. to test muscle damage or local tolerance of drugs, animals should be made familiar with laboratory procedures before any experiment.


Sleep deprivation and impaired cognition. Possible role of brain catecholamines.

To assess the role of brain catecholamines in cognitive decline associated with sleep deprivation, 40 healthy male volunteers were randomized to conditions of total sleep deprivation or 40.5 h of rest. Within each sleep condition, subjects were further randomized to treatment with a 2-day regimen of placebo or alpha-methyl-para-tyrosine (AMPT), a catecholamine synthesis inhibitor. Cognitive performance was measured repeatedly over time using a computerized performance assessment battery. Treatment with AMPT or treatment with sleep deprivation increased sleepiness without producing marked or consistent deterioration in performance. By contrast, subjects who received both treatments reported greater sleepiness than those receiving either treatment alone, and developed severe cognitive impairment on a variety of tasks. These findings, along with previous evidence that catecholamine-enhancing drugs improve performance in sleep-deprived individuals, support the view that decline in cognitive performance during sleep deprivation may be mediated by brain catecholamines.


[Beta-blockers in glaucoma].

The paper presents the main beta-blockers used in glaucoma therapy, the common international nomination and the commercial nominations of these therapeutical agents which have opened up new prospects in the medication of glaucoma. Some pharmacological properties of the beta-blockers are reviewed: the beta-adrenolytic strength, the pharmacodynamic properties, the pharmacokinetic effects, the action principle, the therapeutical effects and also the local and general side effects of the beta-blockers used in glaucoma therapy.


3-substituted-1,2-benzisoxazoles: novel antipsychotic agents.

A series of 3-substituted-6-fluoro-1,2-benzisoxazoles (II) was synthesized and evaluated for potential antipsychotic activity. Many of the compounds displayed potent antipsychotic-like activity in the apomorphine induced climbing in mice (CMA) or spiroperidol binding assays, and compound 42 (HRP 392, 1-[3-(6-fluoro-1,2-benzisoxazol-3-yl)propyl]-4-(2-methoxyphenyl) piperazine) was selected for more detailed antipsychotic evaluation in a battery of preclinical assays. The results of these studies suggests that 42 is a potential antipsychotic drug with less propensity for EPS than some standard neuroleptics in monkeys. The compound was advanced for toxicological evaluation.


Effects of Taxotere and taxol on in vitro colony formation of freshly explanted human tumor cells.

Taxotere (RP 56976, NSC 628503) is a new semisynthetic analog of taxol (NSC 125973) with promising antitumor activity in a variety of preclinical screening systems. Clinical responses after treatment with taxol have been observed in ovarian cancer, breast, lung cancer and melanoma. Both agents act through induction of microtubule polymerization. We have studied and compared the antiproliferative action of Taxotere and taxol against a variety of freshly explanted human tumor specimens using an in vitro soft agar cloning system. Final concentrations of 0.025-10 micrograms/ml were used for both agents in short-term (1 h) or continuous (14 days) incubations. Taxotere was studied using a 1 h incubation in a total of 167 tumor specimens of which 85 (51%) were evaluable. At 10 micrograms/ml, Taxotere inhibited 32 out of 78 (41%) specimens (colony formation less than or equal to 0.5 x control). Cytotoxicity of Taxotere was observed against breast, lung, ovarian, colorectal cancer and melanoma tumor colony forming units. For comparison, 227 specimens were exposed to taxol for 1 h. At 10 micrograms/ml, 32 out of 97 evaluable specimens (33%) were significantly inhibited. Cytotoxicity was observed against breast, lung, ovarian, colorectal cancer and melanoma tumor colony forming units. In head-to-head comparisons, 29 specimens were found more sensitive to Taxotere than taxol, while only 13 were more sensitive to taxol than to Taxotere. These data indicate that cross-resistance between the two agents is incomplete and that on a concentration basis Taxotere is more cytotoxic than taxol in the majority of human primary tumor specimens evaluated.


Methionine-enkephalin immunoreactivity in Merkel cell dense-core granules of nude mice sinus hair. A post-embedding immunogold electron-microscopic study.

The ultra-immunocytochemical technique applied in the present study revealed the occurrence of methionine-enkephalin (met-enkephalin)-like substance in the dense-core granules of Merkel cells of nude mice sinus hair. Incubation of ultra-thin sections of sinus hair with met-enkephalin antisera conjugated with gold particles showed specific association of gold particles on the dense-core granules of the Merkel cells. Gold particles were heavily and specifically located on the dense-core granules as well as in the adjacent cytoplasm. Dense-core granules of degenerating Merkel cells also exhibit met-enkephalin immunoreactivity. The nerve terminals associated with the Merkel cell did not show met-enkephalin immunoreactivity. Therefore, it is concluded that a met-enkephalin-like substance is present and stored in nude mice Merkel cell dense-core granules and it might act as a neurotransmitter or neuromodulator which could be involved in the functioning of the cell. Non-osmicated tissue should be used to locate this substance because of the possibility of cross-linkage of the amino acid sequence with osmium tetroxide.


Possible induction of intercellular adhesion molecule-1 (ICAM-1) expression on endothelial cells by platelet-activating factor (PAF).

We demonstrated that PAF and IL-1 markedly induce ICAM-1 expression on endothelial cells. These findings suggest that PAF not only modulates inflammation by the attraction and activation of eosinophils or by platelet activation, but also intensifies such phenomena by induction of ICAM-1 expression on endothelial cells.


Alpha-linolenic acid and metabolism of cholesterol and long-chain fatty acids.

Animal studies have demonstrated that dietary 18:3n-3 reduces 20:4n-6 content in plasma and tissue lipids. At megadose levels of 18:3n-3, the reduction in phospholipid 20:4n-6 is brought about by a combination of inhibition of desaturase activities and redistribution of 20:4n-6 from phospholipids to neutral lipid pools. The shifting phenomenon is not apparent when the dietary level of 18:3n-3 is low. Dietary 18:3n-3 reduces cholesterol levels in blood and liver tissue; however, the mechanism by which this effect is mediated is not known. Further studies are warranted to investigate the role of dietary 18:3n-3 on cholesterol biosynthesis, storage, and mobilization into and from the tissues and on the secretion of cholesterol into bile. The effect of the ratio of dietary 18:2n-6 to SFA as a determinant of 20:4n-6 and lipid-lowering effects should be further explored in human subjects. It is important to elucidate whether dietary 18:3n-3 interacts with other nutrients to modulate the parameters implicated in the pathogenic processes. The optimum level of dietary 18:3n-3 required to obtain health beneficial effects needs to be determined. Specific effects of dietary 18:3n-3 on low- and high-density lipoprotein cholesterol levels also deserves further investigation before any recommendation to achieve health benefits can be made.


Histamine-2-receptor antagonists and gastric cancer: update and note on latency and covariates.

The relationship between treatment with histamine-2 (H2)-receptor antagonists (cimetidine and ranitidine) and subsequent risk of gastric cancer was analyzed with data of a case-control study conducted in northern Italy between 1983 and 1991 on 628 incident cases of gastric cancer and 1776 control subjects who had been hospitalized for acute, nonneoplastic, non-digestive-tract disorders, with a specific focus on time-risk relationships and analysis of covariates. Previous use of H2-receptor antagonists was reported by 45 (7.2%) cancer patients and 68 (3.8%) control subjects; the corresponding multivariate relative risk (RR) was 2.1 (95% confidence interval [CI] 1.4-3.8). A significantly elevated risk, however, was evident only among individuals (27 patients and 23 control subjects) who had started using the drug less than 5 yr before diagnosis (RR 3.8, 95% CI 2.1-6.1). The risk estimate declined to 2.1 (95% CI 1.0-4.2) for use starting 5-9 yr before diagnosis and to 0.4 (95% CI 0.2-1.2) for use starting greater than or equal to 10 yr before diagnosis. When the relationship between use of H2-receptor antagonists and gastric cancer risk was examined across strata of sex, age, and other selected covariates (educational level, tobacco use, and alcohol and coffee consumption), all RRs were greater than unity for use starting less than 5 yr before diagnosis, but there was no evidence of any consistent association for use starting in the more distant past. Furthermore, there was no evidence of heterogeneity in the RRs for H2-receptor antagonist use and gastric cancer across strata of the covariates examined.(ABSTRACT TRUNCATED AT 250 WORDS)


Postural stability, tardive dyskinesia and developmental disability.

The postural stability of four adult populations was examined through force platform methods. The four groups were classified as: (1) developmentally disabled (severely and profoundly mentally retarded) with tardive dyskinesia; (2) developmentally disabled but with no history of neuroleptic medication; (3) tardive dyskinetic but of normal intelligence; and (4) a normal and healthy control group. Postural conditions included standing still with arms at side, standing still with one arm or both arms parallel to the ground, and standing still while swinging both arms in the sagittal plane. The findings showed that both tardive dyskinetic and/or developmentally disabled groups exhibited greater sway and variability in centre of pressure motion in contrast to the control group. The developmentally disabled with tardive dyskinesia group also exhibited a strong tendency to produce a different form to the postural sway strategy in that they produced rhythmical centre of pressure motions during stance that were, to some degree, task dependent. The findings show that the combined effects of developmental disability and tardive dyskinesia produce qualitatively and quantitatively different features in postural stability patterns. The data suggest that postural stability measures may be a useful index to assess tardive dyskinesia.


Recurrent neuroleptic malignant syndrome in a man with mild mental handicap.

A case of recurrent neuroleptic malignant syndrome (NMS) occurring in a 29-year-old man with mild mental handicap and a superadded psychotic disorder is described. The case illustrates a number of unusual features such as recurrent episodes and resolution with administration of intravenous Procyclidine. The possibility of NMS occurring in people with mental handicap, who have a high level of neuroleptic drug prescription, must be borne in mind.


Plasmid mediated metal and antibiotic resistance in marine Pseudomonas.

Pseudomonas sp isolated from the Bay of Bengal (Madras coast) contained a single large plasmid (pMR1) of 146 kb. Plasmid curing was not successful with mitomycin C, sodium dodecyl sulfate, acridine orange, nalidixic acid or heat. Transfer of mercury resistance from marine Pseudomonas to Escherichia coli occurred during mixed culture incubation in liquid broth at 10(-4) to 10(-5) ml(-1). However, transconjugants lacked the plasmid pMR1 and lost their ability to resist mercury. Transformation of pMR1 into E. coli competent cells was successful; however, the efficiency of transformation (1.49 x 10(2)Hgr transformants microsgm-1 pMR1 DNA) was low. E. coli transformants containing the plasmid pMR1 conferred inducible resistance to mercury, arsenic and cadmium compounds similar to the parental strain, but with increased expression. The mercury resistant transformants exhibited mercury volatilization activity. A correlation existed between metal and antibiotic resistance in the plasmid pMR1.


Vertebrate axis formation.

Molecular understanding of axis formation has recently taken a great leap forward with the identification and functional characterization of regulatory genes that appear to act at the top of the hierarchy leading to positional specification in the vertebrate. Analysis of these genes, which encode peptide growth factors and their receptors as well as transcription factors, is disclosing principles of early cell fate specification that are common to all vertebrates.


Acute myopathy with selective degeneration of myosin filaments following status asthmaticus treated with methylprednisolone and vecuronium.

We report two cases of severe, acute myopathy with selective degeneration of myosin filaments in asthmatics who developed respiratory failure with hypercapnia and acidosis requiring endotracheal intubation, administration of vecuronium and prolonged ventilatory support. Hypoxia was documented in one case and probably present in the other. Both patients received prolonged treatment with high doses of intravenous methylprednisolone. Flaccid quadriparesis was noted after discontinuation of vecuronium. Muscle biopsy showed nonspecific myopathic changes on light microscopy. Electron microscopy revealed selective loss of myosin filaments in many fibers. Recovery occurred within 2 months with supportive treatment. This entity is probably related to a combination of high doses of corticosteroids, vecuronium administration and metabolic abnormalities associated with respiratory failure.


Criteria for diagnosis of familial amyotrophic lateral sclerosis. European FALS Collaborative Group.

Clinical criteria for the diagnosis of motor neuron disease, agreed at the inaugural meeting of the European Familial Amyotrophic Lateral Sclerosis Collaborative Group, are described. The criteria are derived from those developed for the study of sporadic amyotrophic lateral sclerosis, and allow the inclusion of certain recognized clinical sub-types of familial amyotrophic lateral sclerosis. They will require testing for consistency and sensitivity.


Long regions of homologous DNA are incorporated into the tobacco plastid genome by transformation.

We investigated the size of flanking DNA incorporated into the tobacco plastid genome alongside a selectable antibiotic resistance mutation. The results showed that integration of a long uninterrupted region of homologous DNA, rather than of small fragments as previously thought, is the more likely event in plastid transformation of land plants. Transforming plasmid pJS75 contains a 6.2-kb DNA fragment from the inverted repeat region of the tobacco plastid genome. A spectinomycin resistance mutation is encoded in the gene of the 16S rRNA and, 3.2 kb away, a streptomycin resistance mutation is encoded in exon II of the ribosomal protein gene rps12. Transplastomic lines were obtained after introduction of pJS75 DNA into leaf cells by the biolistic process and selection for the spectinomycin resistance marker. Homologous replacement of resident wild-type sequences resulted in integration of all, or almost all, of the 6.2-kb plastid DNA sequence from pJS75. Plasmid pJS75, which contains engineered cloning sites between two selectable markers, can be used as a plastid insertion vector.


Degradation products of the mRNA encoding the small subunit of ribulose-1,5-bisphosphate carboxylase in soybean and transgenic petunia.

The degradation of a soybean ribulose-1,5-bisphosphate carboxylase small subunit RNA, SRS4, was investigated in soybean seedlings and in petunia plants transformed with an SRS4 gene construct. Polyacrylamide RNA gel blot, primer extension, and S1 nuclease analyses were used to identify and map fragments of the SRS4 mRNA generated in vivo. We showed that SRS4 mRNA is degraded to a characteristic set of fragments in soybean and transgenic petunia and that degradation is not dependent on position of insertion of the gene construct within the genome, on the expression level of the SRS4 mRNA, or on the rbcS promoter. Degradation products lacked poly(A) tails and fractionated with poly(A)-depleted RNA on oligo(dT)-sepharose columns. These products pelleted with polysomes and were released from polysomes prepared with EDTA. Sequences at the 5' end of the SRS4 mRNA were more stable than those at the 3' end of the mRNA. Three models for SRS4 mRNA degradation involving endonucleolytic and exonucleolytic degradation were presented to explain the origin of the 5' proximal fragments.


A novel variant of transthyretin (prealbumin), Thr119 to Met, associated with increased thyroxine binding.

A group of patients with prealbumin associated hyperthyroxinemia possess a common single base substitution in the fourth exon of their transthyretin gene. This cytosine to thymine substitution occurs in the codon for residue 119 and results in the predicted replacement of a threonine residue with a methionine at this position. A new NcoI restriction endonuclease cleavage site is created by the point mutation and can be detected by a rapid and simple assay based on the polymerase chain reaction. This variant transthyretin is inherited in an autosomal dominant manner and is apparently not amyloidogenic but is associated with increased thyroxine binding. As healthy heterozygous individuals have normal serum thyroxine concentrations, the hyperthyroxinemia sometimes found may not be primarily due to the variant.