Different brain oxidative and neuroinflammation status in rats during prolonged abstinence depending on their ethanol relapse-like drinking behavior: Effects of ethanol reintroduction.

RATIONALE: Accumulating evidence suggests that chronic alcohol consumption is associated with excessive oxidative damage and neuroinflammatory processes and these events have been associated to early alcohol withdrawal. In the present research we wonder if brain oxidative stress and neuroinflammation remains altered during prolonged withdrawal situations and whether these alterations can be correlated with relapse behavior in alcohol consumption. The effects of alcohol reintroduction were also evaluated METHODS: We have used a model based on the alcohol deprivation effect (ADE) within a cohort of wild-type male Wistar rats. Two subpopulations were identified according to the alcohol relapse-like drinking behavior displayed (ADE and NO-ADE subpopulations). Oxidized and reduced glutathione content was determined within the hippocampus and the amygdala using a mass spectrometry method. The levels of mRNA of seven different inflammatory mediators in the prefrontal cortex of rats were quantified. All the analyses were performed in two different conditions: after 21-day alcohol deprivation (prolonged abstinence) and after 24 h of ethanol reintroduction in both subpopulations. RESULTS: ADE and NO-ADE rats showed different endophenotypes. ADE rats always displayed a significant lower alcohol intake rate and ethanol preference than NO-ADE rats. The results also demonstrated the existence of altered brain redox and neuroinflammation status after prolonged abstinence exclusively in ADE rats. Moreover, when ethanol was reintroduced in the ADE subpopulation, altered oxidative stress and neuroinflammatory markers were restored. CONCLUSIONS: Present findings provide new mechanisms underlying the neurobiology of relapse behavior and suggest the development of new pharmacological approaches to treat alcohol-induced relapse.

Regional differences in mu-opioid receptor-dependent modulation of basal dopamine transmission in rat striatum.

The nigrostriatal dopamine system is implicated in the regulation of reward and motor activity. Dopamine (DA) release in dorsal striatum (DS) is controlled by the firing rate of DA neurons in substantia nigra pars compacta. However, influences at terminal level, such as those involving activation of mu opioid receptors (MORs), can play a key role in determining DA levels in striatum. Nonetheless, published data also suggest that the effect of opioid drugs on DA levels may differ depending on the DS subregion analyzed. In this study, in vivo microdialysis in rats was used to explore this regional dependence. Changes in basal DA levels induced by local retrodialysis application of DAMGO (selective MORs agonist) in three different subregions of DS along the rostro-caudal axis were studied. Our results indicate that whereas administration of 10µM DAMGO into the rostral and caudal DS significantly reduced DA levels, in medial DS an increase in DA levels was observed. These data reveal a regional-dependent MOR modulation of DA release in DS, similar to that described in the ventral striatum. Our findings may lead to a better understanding of the nigrostriatal DA system regulation.

Brain metabolism of ethanol and alcoholism: an update.

It has long been suggested that some of the neuropharmacological, neurochemical and behavioural effects of ethanol are mediated by its first metabolite, acetaldehyde. In spite of the well documented psychoactivity of acetaldehyde, the precise role of this compound in alcohol abuse remains a matter of intense debate among scientists devoted to the study of alcoholism. Very frequently, the main drawback has been related to the presence of adequate levels of acetaldehyde or its derivatives inside the brain after ethanol ingestion. Since penetration into the central nervous system from blood of peripherically derived acetaldehyde is very low due to the high aldehyde dehydrogenase activity at the blood-brain barrier, several authors called into question the acetaldehyde implication in the toxicity and neurobehavioral effects of ethanol. The confirmation in several laboratories of the existence of enzymatic mechanisms of ethanol oxidation in the brain has revitalized the old theories supporting the acetaldehyde contribution to alcohol abuse and alcoholism. In this paper, we review current data on the brain metabolism of ethanol. We focused on the description of the enzymatic mechanisms involved in this metabolic process, reviewing the constitutive expression, catalytic activity and inhibition and inducibility of the enzymes involved in brain ethanol metabolism. We also analyze old and recent data on their regional distribution and cellular localization in the central nervous system, with special reference to the mesocorticolimbic system, a dopaminergic brain pathway that plays an important role in drug and ethanol reinforcement.

Evidence of a flip-flop phenomenon in acamprosate pharmacokinetics: an in vivo study in rats.

The pharmacokinetics of acamprosate were examined in the rat after oral and intravenous administration in order to detect the possible presence of a flip-flop phenomenon. Rats received 9.3 or 73.3 mg/kg of the drug as an intravenous bolus. The same doses were orally administered via gastric intubation. Plasma samples were taken from the jugular vein for determination of acamprosate concentration by liquid scintillation counting. The drug content was also quantified in urine and faeces. The acamprosate bioavailability was close to 20%, the amount recovered in the faeces being around 80% of the administered dose. The terminal slope of the oral plasma curve was significantly lower than that obtained after intravenous administration of the drug at both doses tested (p<2 x 10(-6) in both cases). Moreover, the downward slope after oral administration (lambda2=0.006 +/- 0.001 min(-1)) practically coincided with the first-order absorption rate constant, previously reported by us, obtained using an in situ rat gut technique. It is concluded that the acamprosate absorption rate is considerably slower than its elimination rate so that the drug exhibits flip-flop pharmacokinetics after oral administration. The lower intrinsic first-order absorption rate constant, ka, is responsible for this phenomenon.

Quantitative in vivo microdialysis in pharmacokinetic studies: some reminders.

This paper reviews the empirical methods of quantitative microdialysis that have been used to interpret the results obtained from pharmacokinetic studies. The concept of extraction efficiency or recovery and the properties of recovery in vivo (variation with flow rate, time dependency and influence of the mode of administration) are considered. The most frequently used methods for determining recovery in vivo are described and evaluated in the light of recent theoretical studies. Specifically, we review the variation of flow rate method, the very slow flow method, the no net flux method and the delivery and retrodialysis methods. Special emphasis is placed on the description of each method, demonstrating its applicability to pharmacokinetic studies conducted under steady-state or transient conditions, and also its limitations. Finally, the more relevant studies that have compared the suitability of these methods are reviewed.

Acamprosate blocks the increase in dopamine extracellular levels in nucleus accumbens evoked by chemical stimulation of the ventral hippocampus.

Recently, we have shown that acamprosate is able to modulate extracellular dopamine (DA) levels in the nucleus accumbens (NAc) and may act as an antagonist of N-methyl-D-aspartate (NMDA) receptors. Neurochemical studies show that chemical stimulation (using NMDA) of the ventral subiculum (vSub) of the hippocampus produces robust and sustained increases in extracellular DA levels in the NAc, an effect mediated through ionotropic glutamate (iGlu) receptors. The present study examines whether acamprosate locally infused in the NAc of rats could block or attenuate the increase in NAc extracellular DA elicited by chemical stimulation (with 5 mM NMDA) of the ventral subiculum of the hippocampus. The stimulation of the vSub during perfusion of artificial cerebrospinal fluid in NAc induced a significant and persistent increase in NAc DA levels. Reverse dialysis of 0.05 mM acamprosate in NAc blocked the increase in DA evoked by the chemical stimulation of the vSub. These data support the possibility that the antagonism at the NMDA receptors in NAc can explain, at least in part, the mechanism of action of this drug.

Surgical management of retroperitoneal sarcomas associated with external and intraoperative electron beam radiotherapy.

AIMS: To report outcomes of adults with retroperitoneal sarcoma (RS) treated by surgery, external beam radiotherapy (EBRT) and intraoperative electron beam radiotherapy (IORT). METHODS: From July 1988 to February 2001; 24 patients with primary and recurrent RS were diagnosed and treated. The median dose and energy of IORT delivered was 15 Gy/9meV. EBRT dose varies between 45-50 Gy. RESULTS: There were five primary and 19 recurrent tumours. One primary and five recurrent tumours underwent R0 resection. There were 12 liposarcomas and 19 grade I tumours; 13 patients developed local recurrence and three developed distant metastases.Twenty-two patients received IORT associated with EBRT: 11 developed recurrences. Six patients developed Neurotoxicity (4 grade II and 2 grade III). Disease free survival and overall survival at 5 years was 28 and 56% respectively. CONCLUSIONS: EBRT with IORT treatment is a promising technique for local control. Lower recurrence rates are associated with radical (R0) surgical procedures.

Local acamprosate modulates dopamine release in the rat nucleus accumbens through NMDA receptors: an in vivo microdialysis study.

The effects of acamprosate on the in vivo dopamine extracellular levels in the nucleus accumbens and the involvement of N-methyl-D-aspartate (NMDA) receptors in these effects were investigated. Microdialysis in freely moving rats was used to assess dopamine levels before and during simultaneous perfusion of acamprosate and/or different agonists or antagonists of NMDA receptors. Perfusion with acamprosate at concentrations of 0.5 and 5 mM provoked a concentration-dependent increase in extracellular dopamine in nucleus accumbens. The lowest concentration of acamprosate assayed (0.05 mM) had no effect on dopamine levels. Infusion of NMDA (25 and 500 microM) and the glutamate uptake blocker, L-trans-pyrrolidine-2,4-dicarboxilic acid (PDC) (0.5 mM) into the NAc caused a significant increase in DA, whereas acamprosate (0.05 mM) co-infusion with these compounds blocked or attenuated the NMDA and PDC-induced increases in DA levels. Co-infusion of the selective antagonist of NMDA receptors, DL-2-amino-5-phosphonopentanoic acid (AP5) (400 microM) with acamprosate (0.5 mM), did not reduce the increase of DA levels induced by acamprosate. These results demonstrate that acamprosate is able to modulate DA extracellular levels in NAc via NMDA receptors and suggest that acamprosate acts as an antagonist of NMDA receptors.

[The tobacco industry's internal documents and smoking prevention in Spain]. / Los documentos internos de la industria tabaquera y la prevención del tabaquismo en España.

A 1998 agreement between several states in the USA and the tobacco industry made millions of pages of internal documents available to the public. Many of these documents contain information that the industry would have preferred to keep confidential. Systematic review of these internal documents constitutes a valuable resource for international tobacco control, since they are available on the Internet and can be accessed from anywhere in the world. These documents provide relevant and useful information to antismoking activists and researchers. To facilitate their use, the present article presents the electronic archives of the tobacco industry's documents, describes methods for conducting searches, and identifies the documents with information on the industry's tactics for manipulating Spanish politics and society for its own commercial interests during the 1970s, 1980s, and 1990s.

Quitosanos: usos y aplicaciones en tecnología farmacéutica / Chitosans: uses and applications in pharmaceutical technology

Se presenta una revisión de la gran diversidad de aplicaciones farmacéuticas del quitosano. Tras un breve repaso de la estructura y características fisicoquímicas de los quitosanos, se destaca el uso de este polímero en la elaboración de formas de liberación controlada, ámbito en el cual se está desarrollando una intensa investigación actualmente. Además se analiza la aplicación del quitosano para la mejora de la biodisponibilidad de diversos fármacos mediante su inclusión en formas farmacéuticas administradas a través de distintas vías, así como su capacidad promotora de la absorción intestinal y nasal, discutiendo los posibles mecanismos de acción. También se revisan las aplicaciones más novedosas de los quitosanos como son en la terapia antitumoral, en las vacunas, o incluso en la terapia génica y el transplante de células. Por último, se pone de manifiesto la baja toxicidad y la buena biocompatibilidad de este polímero, que hacen de él un excelente excipiente para la industria farmacéutica y excepcional candidato para futuras formulaciones (AU)

Análise epidemiológica de consenso nacional sobre espasticidade / Epidemiological analysis of nacional consense about spasticity

The National Consense abot Spasticity by Brazilian Society of Physical Medicine and Rehabilitation (SBMFR) and Brazilian Medical Association (AMB) was done based on critical analysis of epidemiological studies, showing that traditional terapeutic resources need more studies for posterior approving

[Study of preoperative risk factors for bacteriobilia in patients with acute calculosis cholecystitis]. / Estudos dos fatores de risco pré-operatórios para bacteriobilia em doentes portadores de colecistite aguda calculosa.

OBJECTIVE: to determine an association between the preoperative clinical status and the result of bile and gallbladder wall cultures. MATERIAL AND METHODS: 28 variables regarding history, physical examination and labatorial assessment in 38 patients with acute calculosis cholecystitis submitted to urgency surgery were prospectively studied during a 19-month period, between November 1995 and May 1997. Cultures for aerobic and anaerobic agents from both the gallbladder wall and the bile were performed, in three different culture media (BACTEC 9240, BHI and HEMOBAC). RESULTS: bacteria were isolated in at least one culture medium, in 68.2% of the patients. At univariate analysis, five preoperative factors were identified as predictors of bactibilia: over 55 years of age, a greater than 0.4 degrees C difference in the axillary-rectal temperature, a greater than 12.000 cels/m3 blood leukocyte count, a greater than 75% neutrophil percentage and a greater than 4% rod neutrophil percentage. Owing to the small sample size, statistical significance of the series could not be noted by logistic regression, although a trend to preoperative determination could be observed in 98% of the subjects with positive culture, by means of the model based on age and percentage of rod neutrophil. By analyzing predictive factors jointly, it was noted that patients with more than one predictive factor have a significantly greater possibility to yielding positive culture when compared to those with up to one predictive factor for bactibilia. CONCLUSIONS: We concluded that, in patients with acute calculosis cholecystitis, bactibilia may be predicted yet at the preoperative period, by using simple and easily obtained data.

Estudos dos fatores de risco pré-operatórios para bacteriobilia em doentes portadores de colecistite aguda calculosa / Study of preoperative risk factors for bactibilia in patients with calculosis acute cholecystitis

OBJETIVO: Determinar uma associaçäo entre o quadro clínico pré-operatório e os resultados das culturas de bile e da parece vesicular. CASUISTICA E METODOS: Foram estudadas 28 variáveis considerando-se história clínica, exame físico e investigaçäo laboratorial em 38 doentes portadores de colecistite aguda calculosa, submetidos à cirurgia de urgência. Este estudo prospectivo foi realizado em 19 meses, entre novembro de 1995 a maio de 1997. Foram realizadas culturas para agentes anaeróbios e aeróbios, em três diferentes meios de cultura (BACTEC 9240, BHI e HEMOBAC). RESULTADOS: Foram isoladas bactérias em pelo menos um meio de cultura em 68,2 por cento dos doentes. Pela anßlise univariada, foram identificadas cinco variáveis pré-operatórias como preditivas de bacteriobilia: idade acima de 55 anos, temperatura diferencial axilo-retal maior do que 0,4 C, leucocitose acima de 12000 cels/mmÝ, neutrofilia acima de 75 por cento e neutrófilos bastonetes acima de 4 por cento. Devido ao pequeno tamanho da amostra, näo pôde ser observada significância estatística por regressäo logística, embora pudesse ser observada em 98 por cento uma tendência para determinaçäo pré-operatória dos indivíduos com cultura positiva por meio do modelo baseado na idade e porcentagem de neutrófilos bastonetes. Pela análise em conjunto dos fatores preditivos, pôde-se observar que doentes com mais de um fator preditivo têm uma possibilidade significantemente maior para cultura positiva, quando comparado com aqueles com fator preditivo de bacteriobilia. CONCLUSAO: Conclui-se, portanto, que pela utilizaçäo de dados facilmente disponíveis em doentes com colecistite aguda calculosa, a bacteriobilia pode ser previsível no pré-operatório,

Evaluation of an enzyme immunoassay for hepatitis C virus antibody detection using a recombinant protein derived from the core region of hepatitis C virus genome

This study was undertaken to evaluate an enzyme immunoassay (EIA) for hepatitis C virus antibody detection (anti-HCV), using just one antigen. Anti-HCV EIA was designed to detect anti-HCV IgG using on the solid-phase a recombinant C22 antigen localized at the N-terminal end of the core region of HCV genome, produced by BioMérieux. The serum samples diluted in phosphate buffer saline were added to wells coated with the C22, and incubated. After washings, the wells were loaded with conjugated anti-IgG, and read in a microtiter plate reader (492 nm). Serum samples of 145 patients were divided in two groups: a control group of 39 patients with non-C hepatitis (10 acute hepatitis A, 10 acute hepatitis B, 9 chronic hepatitis B, and 10 autoimmune hepatitis) and a study group consisting of 106 patients with chronic HCV hepatitis. In the study group all patients had anti-HCV detected by a commercially available EIA (Abbott(r)), specific for HCV structural and nonstructural polypeptides, alanine aminotransferase elevation or positive serum HCV-RNA detected by nested-PCR. They also had a liver biopsy compatible with chronic hepatitis. The test was positive in 101 of the 106 (95 percent) sera from patients in the study group and negative in 38 of the 39 (97 percent) sera from those in the control group, showing an accuracy of 96 percent. According to these results, our EIA could be used to detect anti-HCV in the serum of patients infected with hepatitis C virus.

A prospective and randomized study using ribavirin as monotherapy for the treatment of naïve patients with chronic hepatitis C.

In order to evaluate the response to ribavirin in previously untreated patients with chronic hepatitic C, 39 patients were selected for a double-blind prospective and randomized trial, and divided into two groups: ribavirin-group (19 patients) and placebo-group (20 patients). Ribavirin was administered orally for 24 weeks (600 mg/day, followed by 1,000 mg/day and 1,200 mg/day each one for 8 weeks). After 3 months of drug administration, the patients were evaluated by measuring biochemical, virologic and histologic responses. After this phase, ribavirin was offered to the patients who had received placebo (second phase). The results showed that the patients who received ribavirin showed a higher reduction in serum alanine aminotransferase (ALT) activity than patients in the placebo group. Among the patients in the ribavirin-group, a complete biochemical response (ALT levels normalized) was observed in 3 patients (16%), and a partial response (reduction greater than 50% of the initial value of ALT activity) in 4 (21%). In the 20 patients in the placebo group, only 1 showed a partial response (5%). In the second phase of the study, among 16 patients who received ribavirin, 4 (25%) showed a complete and 5 (31%) a partial biochemical response. HCV-RNA did not become negative in any patient during the two phases. A reduction in the score of portal and lobular activity was observed in patients who received ribavirin, but statistical analysis did not identify differences. This study showed that ribavirin alone induces a biochemical response (ALT reduction) in some patients with chronic hepatitis C, which may be associated with a reduction in hepatic inflammatory activity reduction, but the changes are not sufficient to recommend initial monotherapy with ribavirin.

Evaluation of an enzyme immunoassay for hepatitis C virus antibody detection using a recombinant protein derived from the core region of hepatitis C virus genome.

This study was undertaken to evaluate an enzyme immunoassay (EIA) for hepatitis C virus antibody detection (anti-HCV), using just one antigen. Anti-HCV EIA was designed to detect anti-HCV IgG using on the solid-phase a recombinant C22 antigen localized at the N-terminal end of the core region of HCV genome, produced by BioMérieux. The serum samples diluted in phosphate buffer saline were added to wells coated with the C22, and incubated. After washings, the wells were loaded with conjugated anti-IgG, and read in a microtiter plate reader (492 nm). Serum samples of 145 patients were divided in two groups: a control group of 39 patients with non-C hepatitis (10 acute hepatitis A, 10 acute hepatitis B, 9 chronic hepatitis B, and 10 autoimmune hepatitis) and a study group consisting of 106 patients with chronic HCV hepatitis. In the study group all patients had anti-HCV detected by a commercially available EIA (Abbott), specific for HCV structural and nonstructural polypeptides, alanine aminotransferase elevation or positive serum HCV-RNA detected by nested-PCR. They also had a liver biopsy compatible with chronic hepatitis. The test was positive in 101 of the 106 (95%) sera from patients in the study group and negative in 38 of the 39 (97%) sera from those in the control group, showing an accuracy of 96%. According to these results, our EIA could be used to detect anti-HCV in the serum of patients infected with hepatitis C virus.

Kinetic study of acamprosate absorption in rat small intestine.

Acamprosate (calcium bis acetyl-homotaurine), a homotaurine derivative, a structural analogue of gamma-aminobutyric acid (GABA) and an upper homologue of taurine, is a relatively new drug used to prevent relapse in weaned alcoholics. When administered orally as enteric-coated tablets at relatively high doses, this drug has a bioavailability of about 11%; however, the intestinal absorption mechanism has not been studied in depth. The present study was therefore planned to characterize the intestinal transport of acamprosate in the rat and the effect of chronic alcohol treatment on this process, quantifying its kinetic parameters and investigating possible inhibitors. Using an in vitro technique, acamprosate absorption was measured in the rat intestine from three different groups: alcohol group [fed a liquid diet containing 5% (w/v) ethanol for 4 weeks], isocaloric pair-fed control, and a solid diet group. Intestinal acamprosate absorption was found to occur mainly by passive diffusion with a diffusive permeability of 0.213+/-0.004 cm/h in control pair-fed animals, 0.206+/-0.001 cm/h in animals receiving chronic alcohol treatment, and 0.193+/-0.001 cm/h in the solid diet group. Inhibition studies showed that at a 10(-3) M acamprosate concentration, some compounds such as GABA, taurine, proline, and glycine at 40 mM each did not affect acamprosate transport. Nevertheless, when a lower concentration of the drug (10(-4) M) was assayed, a significant reduction of acamprosate transport in the presence of taurine or GABA 40 mM was found. These results suggest that acamprosate in the rat jejunum, could be transported, in part, by a carrier system. Further experiments using different concentrations of taurine (10, 20, and 80 mM) showed that the maximum inhibition (32%) is achieved at 20 mM of taurine. These latter results suggest that acamprosate and taurine share, at least, an intestinal carrier system in rat jejunum. From the above results, it can be concluded that there are probably two pathways involved in the intestinal absorption of acamprosate: passive diffusion and mediated transport, with the former being predominant. Moreover, neither chronic ethanol intake nor the type of diet seems to alter the intestinal absorption of the drug.

Neurotoxic relationship between dopamine and iron in the striatal dopaminergic nerve terminals.

The neurotoxic effect of dopamine (DA) and iron(III) on DAergic terminals in striatum has been studied by intracerebral microdialysis technique. Twenty-four hours after surgery (day 1), DA and/or iron(III) with and without DA reuptake inhibitor, nomifensine, were perfused for 1 h. Forty-eight hours after surgery (day 2), MPP(+) 1 mM was perfused for 15 min and the output of DA was measured, its amount being directly proportional to the remaining striatal DAergic terminals, supported by tyrosine hydroxylase immunohistochemistry technique. Perfusion of exogenous DA, as well as iron(III) 10 and 100 microM, did not produce any neurotoxic effect. However, perfusion of iron(III) (333 and 1000 microM) produced a concentration-dependent toxic effect. Co-perfusion of iron(III) at non-toxic concentration (100 microM) with DA (15 microM) produced a toxic effect. Elevation of the endogenous extracellular levels of DA by inhibiting its uptake with nomifensine increased the neurotoxic effect of iron(III) in a dose-dependent manner. The use of tetrodotoxin after elevation of DA with nomifensine partially prevented the neurotoxic effect of its co-perfusion with iron(III) (100 microM). These results suggest that DAergic system could be synergistically damaged by DA and iron(III). Thus, alterations in the clearance of DA from extracellular space along with an increase of iron may have significant consequences for DAergic system toxicity.

Fine needle aspiration of thoracic lesions: experience in a Brazilian cancer center.

STUDY OBJECTIVES: This study is a retrospective analysis of cytological specimens of fine needle aspiration (FNA) of thoracic lesions under computed tomography guidance, over a 2-year period to assess the diagnostic performance of cytology method. DESIGN: A total of 134 aspirations were performed using a 22 and 20 gauge needle (spinal long). The cytological diagnosis was achieved in 126 cases (94%). The histopathological findings were correlationed in order observe the cytologic diagnosis performance. PATIENTS: The cases were obtained from patients examined at A. C. Camargo Hospital ambulatory. RESULTS: There were 89 cases of malignant lesions (66.4%), 27 benign lesions (20%) and 10 cases (7.5%) of suspected for malignancy. The correlation with histopathology was possible in cases with previous histopathological exams and with tissue diagnosis after puncture. The correlation between FNA and histology showed an overall sensitivity of 77%, specificity of 100%, false-negative rate of 20% and no false-positive results. CONCLUSIONS: We conclude that FNA is a sensitive and highly specific technique for the diagnosis of thoracic neoplasms.