Anxiolytic effects of ethanol are partially related to a reduced expression of adenylyl cyclase 5 but not to µ-opioid receptor activation in rat nucleus accumbens.

Anxiolytic effects of alcohol participate in the reinforcing properties of the drug, in which nucleus accumbens (NAcc) is implicated. The opioidergic system in NAcc is considered a main pathway involved in the emotional responses of animals: rats microinjected with morphine in NAcc and the systemic administration of µ-opioid receptors (MOR) agonists yield low anxiety scores in the elevated plus maze (EPM), a behavioral test of anxiety. However, the specific participation of NAcc MOR in the anxiolytic effect of ethanol has not been studied. AC5, a cAMP-synthezising adenylyl-cyclase, is highly expressed in NAcc; it is negatively coupled to MOR and has been implicated in anxiety levels of animals. We evaluated the anxiolytic effects of an intra-gastric administration of ethanol (2.5 g/kg) in animals subjected to EPM at 1, 4, and 8 h after drug or water exposure. Locomotion was assayed with the open-field test; we also measured accumbal AC5 and MOR mRNA levels by RT-PCR. After 1 h, ethanol-exposed animals showed anxiolytic-like behavior, as well as decreased and increased AC5 and MOR expression in NAcc, respectively. Intra-accumbal injection of ß-funaltrexamine (FNA), a MOR antagonist, did not block ethanol-induced anxiolysis, rather it induced a tendency to increase anxiety levels in the water-exposed group. FNA partially decreased accumbal AC5 expression in ethanol-treated rats. We concluded that AC5 in NAcc is participating in the emotional effects of ethanol; that MOR was not mediating the drug-induced AC5 reduction in NAcc nor the ethanol-induced anxiolysis. MOR only might be involved in basal levels of anxiety of animals.

Both sulfate-reducing bacteria and Enterobacteriaceae take part in marine biocorrosion of carbon steel.

AIMS: In order to evaluate the part played in biocorrosion by microbial groups other than sulfate-reducing bacteria (SRB), we characterized the phylogenetic diversity of a corrosive marine biofilm attached to a harbour pile structure as well as to carbon steel surfaces (coupons) immersed in seawater for increasing time periods (1 and 8 months). We thus experimentally checked corroding abilities of defined species mixtures. METHODS AND RESULTS: Microbial community analysis was performed using both traditional cultivation techniques and polymerase chain reaction cloning-sequencing of 16S rRNA genes. Community structure of biofilms developing with time on immersed coupons tended to reach after 8 months, a steady state similar to the one observed on a harbour pile structure. Phylogenetic affiliations of isolates and cloned 16S rRNA genes (rrs) indicated that native biofilms (developing after 1-month immersion) were mainly colonized by gamma-proteobacteria. Among these, Vibrio species were detected in majority with molecular methods while cultivation techniques revealed dominance of Enterobacteriaceae such as Citrobacter, Klebsiella and Proteus species. Conversely, in mature biofilms (8-month immersion and pile structure), SRB, and to a lesser extent, spirochaetes were dominant. CONCLUSIONS: Corroding activity detection assays confirmed that Enterobacteriaceae (members of the gamma-proteobacteria) were involved in biocorrosion of metallic material in marine conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: In marine biofilms, metal corrosion may be initiated by Enterobacteriaceae.

Beneficial effects of atorvastatin on sd LDL and LDL phenotype B in statin-naive patients and patients previously treated with simvastatin or pravastatin.

BACKGROUND: The presence of increased levels of small dense (sd) LDL (phenotype B) is associated with a substantial increase of cardiovascular disease risk. Since lowering of plasma low-density lipoprotein-cholesterol (LDL-C) by statins involves an up-regulation of the LDL receptor, we questioned whether LDL lowering by atorvastatin affects different LDL subfractions equally. METHODS: Fifty-four hypercholesterolemic patients, requiring treatment for prevention of coronary heart disease received atorvastatin (10, 20 or 40 mg/day), either as initial therapy (n=33), or as replacement therapy (n=21) for pravastatin or simvastatin (both at 40 mg/day). In addition to plasma lipid measurements, cholesterol LDL subfractions were separated and analysed before and after 3 months of treatment. RESULTS: In addition to the expected LDL-C decrease (-34%; p<0.0001), a major reduction in sd LDL occurred after atorvastatin therapy (-38.2%; p<0.0001). Interestingly, sd LDL decreased as much in patients previously treated with other statins (-36%; p<0.002). A close correlation (r=0.89, p<0.001) was found between reduction of sd LDL and that of LDL-C, in patients with phenotype B. Although high-density lipoprotein-cholesterol (HDL-C) was not affected by atorvastatin treatment, plasma triglycerides decreased by 27.4% (p<0.0001). Only a weak correlation (r=0.35, p<0.01) was found between the reduction of plasma triglycerides and the decrease of sd LDL after atorvastatin treatment. CONCLUSION: These results show that the reduction of LDL-C by atorvastatin largely reflects a lowering of sd LDL. Our data also suggest that triglyceride lowering plays only a partial role in sd LDL reduction.

T-cell flow-cytometry crossmatch and long-term renal graft survival.

Flow cytometry crossmatch (FCXM) is a more sensitive technique than classical complement-dependent cytotoxicity (CDC) for the detection of donor-directed antibody before renal transplantation. Nevertheless, the role of FCXM in predicting long-term survival of kidney grafts is still unclear. The purpose of our study was to evaluate the impact of a positive T-cell FCXM (T-FCXM) on long-term kidney allografts outcome. Of the 184 consecutive kidney transplantations performed in our center between 1 January1991 and 15 November 1996 a FCXM, performed concurrently to the pre-transplant CDCXM, was available for 170 patients. The CDCXM was negative in all recipients. Among these recipients, 12 (7.1%) had a positive T-FCXM. These patients were not different from patients with a negative T-FCXM for donor and recipient age, sex, frequency of second transplantation, number of human leukocyte antigen matches or mismatches. Frequency of immunized patients was higher in kidney recipients with a positive FCXM (58.3% vs. 24.7%; p=0.02, chi-square test). Survival analysis revealed that kidney graft outcome was better in negative T-FCXM recipients (p=0.03), while patient survival was not statistically different. Our results suggest that a positive pre-transplant T-FCXM despite a negative CDCXM is associated with an impaired long-term graft survival in renal allotransplantation.

Production of exopolysaccharide by Lactobacillus rhamnosus R and analysis of its enzymatic degradation during prolonged fermentation.

The potential of Lactobacillus rhamnosus R for producing exopolysaccharide (EPS) when grown on basal minimum medium supplemented with glucose or lactose was investigated. EPS production by L. rhamnosus R is partially growth associated and about 500 mg of EPS per liter was synthesized with both sugars. The product yield coefficient (Y(EPS/S)) was 3.15 (0.0315 g of EPS [g of lactose](-1)) and 2.88 (0.0288 g of EPS [g of glucose](-1)). It was clearly shown that the amount of EPS produced declined upon prolonged fermentation. Degradation of EPS in fermentation processes was also assessed by measuring its molecular weights and viscosities. As these reductions might have a negative effect on the yield and viscosifying properties of EPS, it was essential to examine possible causes related to this breakdown. The decrease in viscosities and molecular weights of EPS withdrawn at different cultivation times permitted us to suspect the presence of a depolymerizing enzyme in the fermentation medium. Our study on enzymatic production profiles showed a large spectrum of glycohydrolases (alpha-D-glucosidase, beta-D-glucosidase, alpha-D-galactosidase, beta-D-galactosidase, beta-D-glucuronidase, and some traces of alpha-L-rhamnosidase). These enzymes were localized, two of them (alpha-D-glucosidase and beta-D-glucuronidase) were partially purified and characterized. When incubated with EPS, these enzymes were capable of lowering the viscosity of the polymer as well as liberating some reducing sugars. Upon prolonged incubation (27 h), the loss of viscosity was increased up to 33%.

El uso clinico de emulsiones de lipidos / Clinical use of lipid emulsions

Se han realizado progresos sustanciales en la comprensión del metabolismo de las emulsiones endovenosas de lipidos y en la forma como sus componentes llegan a tejidos y células específicos. Las emulsiones de lipidos deben considerarse no solamente medios para proveer sustratos de energía, sino proveedores de compuestos específicos que participan en la regulación de funciones metabólicas claves. Estos mayores conocimientos deben encontrar su aplicación en el cuidado metabólico de diversos tipos de pacientes

Cytochrome P-450 2E1 activity and oxidative stress in alcoholic patients.

As cytochrome P-450 2E1 (CYP2E1) induction was related to oxidative stress in experimental models, the aim of this study was to investigate the relationship between CYP2E1 activity and markers of oxidative stress in 40 alcoholic patients entering a rehabilitation programme. Plasma oxidized proteins, lipid peroxides (LPO) and antibodies against hydroxyethyl radical (HER) or malondialdehyde (MDA) adducts were assessed as markers of the production of free radicals, whereas vitamin E levels were evaluated as a marker of the antioxidant defence. CYP2E1 activity was determined by using the 6-hydroxychlorzoxazone:chlorzoxazone blood metabolic ratio, 2 h after drug intake. This ratio was increased by 4-fold in alcoholics, compared to non-alcoholic patients, and was correlated with daily intake of ethanol, carbohydrate-deficient transferrin, and blood alcohol level at the time of admission to hospital. Plasma levels of LPO and oxidized proteins were slightly increased (20%) in alcoholic patients when compared with the control group, whereas those of vitamin E were found to be slightly decreased (by 18%). Antibodies against HER or MDA adducts showed a very significant increase. However, when alcoholic patients were divided into two groups according to low or high CYP2E1 induction, no significant difference was observed in the variation of these parameters, except for anti-HER adducts antibodies. Therefore, our study confirms the main involvement of CYP2E1 in HER production. By contrast, CYP2E1 does not appear to be the main factor responsible for the oxidative stress occurring during human chronic alcoholism. Free radicals from other sources may therefore contribute significantly to the generation of this oxidative stress.

Advances in intravenous lipid emulsions.

Over the past decade, our views have considerably evolved with respect to the metabolism of intravenous lipid emulsions and their composition. Substantial progress has been made in understanding the metabolic pathways of emulsion particles and the delivery of their various components (fatty acids and vitamins) to specific tissues or cells. Although soybean long-chain triglycerides represent a valuable source of energy, concerns have been raised about their high content of polyunsaturated fatty acids (mainly n-6 essential fatty acids), which may adversely affect immune functions and antioxidant status. Introduction of medium-chain triglycerides or olive oil to lipid emulsions can largely help bypass these disadvantages. Recently, incorporation of n-3 fatty acids in lipid preparations was suggested to have potential application in several chronic and acute diseases because of their ability to reduce inflammatory and thrombotic responses and cell sensitivity to various stimuli. Hence lipid emulsions should no longer be considered only as a means of providing energy substrates; they also modulate key metabolic functions. Such improved knowledge may lead to optimizing the metabolic care of certain patients.

Clinical use of lipid emulsions.

Substantial progress has been made in the understanding of the metabolism of intravenous lipid emulsions and the delivery of their various components to specific tissues or cells. Lipid emulsions should be considered not only as a means of providing energy substrates but also specific compounds that participate in the regulation of key metabolic functions. Such improved knowledge should find applications in the metabolic care of different types of patients.

Involvement of cytochromes P-450 2E1 and 3A4 in the 5-hydroxylation of salicylate in humans.

Hydroxylation of salicylate into 2,3 and 2,5-dihydroxybenzoic acids (2,3-DHBA and 2,5-DHBA) by human liver microsomal preparations was investigated. Kinetic studies demonstrated that salicylate was 5-hydroxylated with two apparent Km: one high-affinity Km of 606 microM and one low-affinity Km greater than 2 mM. Liver microsomes prepared from 15 human samples catalyzed the formation of 2,5-DHBA at metabolic rate of 21.7 +/- 8.5 pmol/mg/min. The formation of 2, 3-DHBA was not P-450 dependent. Formation of 2,5-DHBA was inhibited by 36 +/- 14% following preincubation of microsomes with diethyldithiocarbamate, a mechanism-based selective inhibitor of P-450 2E1. Furthermore, the efficiency of inhibition was significantly correlated with four catalytic activities specific to P-450 2E1, whereas the residual activity was correlated with three P-450 3A4 catalytic activities. Troleandomycin, a mechanism-based inhibitor selective to P-450 3A4, inhibited by 30 +/- 12% the 5-hydroxylation of salicylate, and this inhibition was significantly correlated with nifedipine oxidation, specific to P-450 3A4. The capability of seven recombinant human P-450s to hydroxylate salicylate demonstrated that P-450 2E1 and 3A4 contributed to 2, 5-DHBA formation in approximately equal proportions. The Km values of recombinant P-450 2E1 and 3A4, 280 and 513 microM, respectively, are in the same range as the high-affinity Km measured with human liver microsomes. The plasmatic metabolic ratio 2,5-DHBA/salicylate, measured 2 h after ingestion of 1 g acetylsalicylate, was increased 3-fold in 12 alcoholic patients at the beginning of their withdrawal period versus 15 control subjects. These results confirm that P-450 2E1, inducible by ethanol, is involved in the 5-hydroxylation of salicylate in humans. Furthermore, this ratio was still increased by 2-fold 1 week after ethanol withdrawal. This finding suggests that P-450 3A4, known to be also inducible by alcoholic beverages, plays an important role in this increase, because P-450 2E1 returned to normal levels in less than 3 days after ethanol withdrawal. Finally, in vivo and in vitro data demonstrated that P-450 2E1 and P-450 3A4, both inducible by alcohols, catalyzed the 5-hydroxylation of salicylate.

Pathological gambling and substance misuse: a review of the literature.

This paper reviews research conducted on the link between pathological gambling and substance misuse. We first examine the phenomenon of "pathological gambling," including similarities between pathological gambling and substance misuse, instruments used to measure pathological gambling, and the prevalence of pathological gambling in the United States and internationally. We then examine research on substance misuse among pathological gamblers, pathological gambling among substance misusers, and the treatment of the pathological gambler-substance misuser. We conclude with a discussion of future research needs.

Impaired renal graft survival after a positive B-cell flow-cytometry crossmatch.

BACKGROUND: The clinical and immunological relevance of a positive B-cell flow-cytometry (B-FCXM) crossmatch in renal transplantation is still controversial. METHODS: We retrospectively analysed 145 consecutive cadaveric renal transplantations performed from May 1991 to September 1995 in our institution. All grafts were transplanted following a negative IgG T-cell complement-dependent cytotoxicity crossmatch (T-CDCXM). Concomitantly to CDCXM, B-cell and T-cell FCXM were performed and results were expressed as a mean fluorescence index (FI). Two groups were compared: 116 recipients grafted with a negative B-FCXM vs a group of 19 patients grafted with a positive B-FCXM. RESULTS: The two groups were similar for length of cold ischaemia, donor and recipient's age and degree of HLA mismatching. The proportion of patients with pre-transplant anti-HLA class I antibodies or a retransplantation was significantly increased in the positive B-FCXM group vs the negative B-FCXM group. Recipient survival at 48 months was not significantly different in the two groups. However, graft survival at 12 and 48 months was significantly poorer in the positive B-FCXM than in negative B-FCXM (68% vs 90% at 12 months: P = 0.007, and 57% vs 79% at 48 months: P = 0.02). Within the positive B-FCXM group, no differences were found in pre-transplant anti-HLA class I or II alloimmunization as well as retransplantation frequency between the patients who lost their graft and the patients who did not. CONCLUSION: Our results suggest that a pretransplant positive B-FCXM is associated with an impaired long-term graft survival in renal allotransplantation.

Cytochrome P4502E1 inducibility and hydroxyethyl radical formation among alcoholics.

BACKGROUND/AIMS: Animal studies have shown that the induction of cytochrome P4502E1 (CYP2E1) modulates oxidative damage induced by ethanol. Since CYP2E1 activity varies substantially in humans, we have investigated whether differences in CYP2E1 activity might influence the formation of hydroxyethyl free radicals and the stimulation of lipid peroxidation among alcohol abusers. METHODS: Chlorzoxazone oxidation, an index of CYP2E1 activity, and the levels of antibodies reacting with hydroxyethyl radical and malonyldialdehyde protein adducts were investigated in 51 alcoholic patients. RESULTS: We observed that in 40 out of 51 (78%) alcoholics, chlorzoxazone oxidation was increased over the control levels, consistently with CYP2E1 induction by ethanol. However, in the remaining 22% of the patients, in spite of a similar alcohol intake, chlorzoxazone oxidation was within the control range, indicating a lack of CYP2E1 inducibility. IgG reacting with hydroxyethyl free radical-protein adducts were absent in subjects without CYP2E1 induction, while they were significantly increased in alcoholics with induced CYP2E1 activity. IgG against malonyldialdehyde protein-adducts were increased in all patients, irrespective of CYP2E1 inducibility. Moreover, chlorzoxazone oxidation was significantly lower in alcoholics without clinical and biochemical signs of liver disease as compared to patients with alcoholic liver disease. CONCLUSIONS: These results indicate that CYP2E1 activity greatly influences the formation of hydroxyethyl radicals in humans, and suggest a possible role of CYP2E1 in the development of alcoholic liver disease.

Risk factors associated with suicide attempt in young French people.

Demographic data, personal and familial characteristics, as well as DSM-III-R-based psychiatric diagnoses were collected in 369 adolescents and young adults aged between 15 and 29 years, referred to an Emergency Department for psychological problems. In total, 60% of them were suicide attempters. Separations before the age of 12 years and depression in the family emerged as the main features distinguishing the suicidal group from the psychiatric control group. Fifty per cent of suicide attempters were repeaters. Fostering during childhood, suicide attempts and depression in the family were found to be risk factors for repeated self-attempts. These results support the view that significant levels of dysfunction, together with increased psychiatric morbidity, especially suicidal behaviour, characterize the families of young self-attempters.

Suicide attempts and job insecurity: a complex association.

OBJECTIVE: Since Durkheim, epidemiological studies have revealed a significant, complex association between unemployment and suicidal behaviour. The aim of this study was to analyse the relationship between parasuicide and job instability, including unemployment, French social measures against unemployment and occasional work. METHOD: Demographic data, personal and familial characteristics were collected in 541 suicide attempters. RESULTS: Seventy-seven per cent were socially active, with 61.5% in regular employment, and 38.5% in precarious employment. The female-to-male ratio approached 2 in the securely employed sample, and fell to 1 for those with poor social and professional integration. Depression, parasuicide, and alcohol abuse were more common in the families of repeaters in secure employment. The impact of the familial psychiatric background was no longer significant in the job insecurity group. Fostering in childhood was a risk factor for repeat suicidal behaviour in the group with job insecurity.

[Prospective study of attempted suicide]. / Enquête prospective sur les tentatives de suicide.

The present study involves a prospective review of all patients who visited the Emergency Psychiatric Service during the period from December, 6, 1993 to June, 5, 1994. A questionnaire was proposed to 1073 subjects (57.2% females; 42.8% males; mean age = 36.6 +/- 0.89). Demographic data, familial and personal characteristics, previous contacts with professional health services, and diagnosis (DSM III-R criteria) were collected. 52% of them were self-attempters, significatively younger (mean age 34.03 +/- 1.14) and more frequently females (61.5%). The parasuicides were more frequent in their families and in their personal past history. The previous contacts with health services (hospitalizations, consultations) were more frequent among patients who were admitted for psychological and/or psychiatric problems. 54% of self-attempters were repeating suicidal patients. There were more depressive disorders, parasuicides and drug/alcohol abuse in their families. A logistic regression analysis (stepwise) revealed the role of these factors in the repetition of parasuicides. This data supports the significance of a better knowledge of the potential significant factors for parasuicide. Preventive measures are necessary.