Behavior of oxidation in the radiochromic gel dosimeter through photoacoustic technique measurements

Natural oxidation is an undesirable process suffered by gel dosimetry systems as it changes the values and spatial distribution of absorbed doses. Natural oxidation of Fricke xylenol gel (FXG) dosimeter was inferred from optical absorbance values measured for the first time using the photoacoustic technique. An acoustic detector measures the intensity of the light transmitted by the FXG, which is directly proportional to the ionizing radiation dose absorbed by the samples. In this work, we demonstrated the behavior, the rates, and the dependence of natural oxidation on storage temperature, time, and active components through measurements by photoacoustic technique.

Extracellular amino acid levels in the human liver during transplantation: a microdialysis study from donor to recipient

Using microdialysis, we have monitored extracellular levels of amino acids and related amines in the human liver at three stages of the transplantation procedure: donor retrieval, back table preparation and during 48 h post-implantation. By comparing the ratio of mean levels at the donor and back table stages, with the ratio between early (2-6 h) and late (43-48 h) post-reperfusion, these amines were classified into one of three groups. In one group, back table levels were markedly higher than during the donor stage, with levels declining over time post-reperfusion. A second group had much lower levels in the back table than during the donor phase, and post-reperfusion levels were either stable or increased over time. Concentrations of amino acids in the final group remained relatively constant at all stages. This study illustrates the value of microdialysis in providing organ-specific metabolic data that may indicate specific mechanisms of poor graft function.

Assessment of DNA damage by extracts and fractions of Strychnos pseudoquina, a Brazilian medicinal plant with antiulcerogenic activity

Strychnos pseudoquina St. Hil. is a native plant of the Brazilian Savannah, used in popular medicine to treat a number of conditions. Since it contains large quantities of alkaloids with proven antiulcer activity, we tested the genotoxic potential of crude extracts and fractions containing alkaloids and flavonoids from the leaves of this plant, on Salmonella typhimurium and performed the micronucleus test on peripheral blood cells of mice treated in vivo. The results showed that the methanol extract of the leaves of S. pseudoquina is mutagenic to the TA98 (-S9) and TA100 (+S9, -S9) strains of Salmonella. The dichloromethane extract was not mutagenic to any of the tested strains. Fractions enriched with alkaloids or flavonoids were not mutagenic. In vivo tests were done on the crude methanol extract in albino Swiss mice, which were treated, by gavage, with three different doses of the extract. The highest dose tested (1800 mg/kgb.w.) induced micronuclei after acute treatment, confirming the mutagenic potential of the methanol extract of the leaves of S. pseudoquina. In high doses, constituents of S. pseudoquina compounds act on DNA, causing breaks and giving rise to micronuclei in the blood cells of treated animals.

The role of adrenal corticosteroids in the anti-inflammatory effect of the whole extract of Harpagophytum procumbens in rats

This study was carried out to evaluate whether the anti-inflammatory response in rats to the whole extract of Harpagophytum procumbens is a consequence of adrenal corticosteroid release. Carrageenan-induced inflammatory responses in the hindpaws were evaluated in control, sham-operated and adrenalectomized rats. The extract was administered orally (by gavage) or intraperitoneally, 30min prior to injury stimulus. Blood samples were then collected, and the number of circulating leukocytes was estimated. Pretreatment with the whole extract of H. procumbens reduced the intensity of inflammatory response in normal, sham-operated and adrenalectomized animals. When administered orally, the extract was ineffective. The reduced number of circulating leukocytes observed following intraperitoneal injection of the extract characterized adrenal hyperactivity. The inhibitory effect of the whole extract of H. procumbens on acute inflammatory response in the rat, when administered intraperitoneally, does not depend on the release of adrenal corticosteroids.

Cerebral blood flow during supine rest and the first minute of head-up tilt in patients with orthostatic intolerance

AIM

To assess the cerebral blood flow velocity during the first minute of head-up tilt in patients with postural tachycardia syndrome (POTS) or neurally-mediated reflex syncope compared with patients with dizziness.

METHODS

We evaluated 120 patients selected from 470 patients who underwent head-up tilt testing: 40 with POTS, 40 with typical neurally-mediated reflex syncope and 40 who complained of dizziness with no history of loss of consciousness and a negative head-up tilt test (with and without isosorbide). Transcranial Doppler sonography of the middle cerebral artery, heart rate and brachial blood pressure were recorded during a 70 degrees head-up tilt test.

RESULTS

During both baseline in supine position and the first minute of upright tilt, patients with postural tachycardia syndrome showed higher heart rate and cerebral blood flow velocity than patients with dizziness and patients with neurally-mediated reflex syncope (P < 0.05, ANOVA), but no significant difference was observed on the Gosling's pulsatility index.

CONCLUSION

Patients with POTS have an autonomic dysfunction that is not triggered by upright posture but is accentuated by it.

Surgery for hilar cholangiocarcinoma; a 10 year experience of a tertiary referral centre in the UK

OBJECTIVE

To review the outcome of patients operated for hilar cholangiocarcinoma and analyse prognostic variables.

PATIENTS AND METHODS

A prospectively collected database on patients with hilar cholangiocarcinoma, between 1992 and 2003, and relevant clinical notes were reviewed retrospectively. A total of 174 patients, 96 male, median age 63 years (27-86), were referred. Jaundice was the initial presentation in 167.

RESULTS

ERCP was the initial interventional investigation at the referring centre in 150, of which only 30 were stented successfully. PTC and decompression was carried out on 120. In 17, combined PTC and ERCP were required for placement of stents. Seventy-two underwent laparotomy at which 27 had locally advanced disease. Forty-five had potentially curative resections. Extra hepatic bile duct resection was done in 14 patients of which four were R0 resections. Thirty-one had bile duct resection including partial hepatectomy with 19 R0 resections (P=0.042). Post-operative complications developed in 19 patients, and there were 4 30 day mortalities [hepatic insufficiency:/sepsis (n=3), thrombosis of the reconstructed portal vein (n=1)]. Among the patients with R0 resections, the cumulative survival rates at 1, 3, and 5 year; was 83, 58, 41%, respectively, and in those with R1 resections were 71, 24, 24%, respectively, (P=0.021). Overall survival was shorter in patients with positive perineural invasion (P=0.066: NS). There was no significant difference in survival between the node positive and negative group. Median survival of patients who underwent liver resection was longer than those with bile duct resection only (30 vs 24 months P=0.43: NS).

CONCLUSIONS

ERCP was associated with a high failure rate in achieving pre-operative biliary decompression which was subsequently achieved by PTC. Clear histological margins were associated with improved survival and were better achieved by liver resection as compared to extra hepatic bile duct resection. Positive level I lymph nodes did not adversely impact survival.

Selection of glycoprotein IIb/IIIa inhibitors for upstream use in patients with diabetes experiencing unstable angina or non-ST segment elevation myocardial infarction. What have we learned in the last 10 years?

Coronary disease accounts for the majority of deaths among patients with diabetes and the thrombotic milieu accelerated by diabetes results in unstable angina (UA), non-ST segment elevation myocardial infarction (NSTEMI) or ST-segment elevation myocardial infarction (STEMI) or death. Upstream use of a glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitor with percutaneous coronary intervention (PCI) as part of an early invasive approach is preferred. However substantial numbers of patients present to rural or non-teaching hospitals without immediate access to a catheterization laboratory. Enhanced GP IIb/IIIa receptor mobilization, TXA2 production and platelet activation together present an extensive thrombotic challenge that may not be overcome with current doses of GP IIb/IIIa inhibitors when used without PCI. Heterogeneity of platelet aggregometric analysis may have identified GP IIb/IIIa doses used in clinical trials that may not fully overcome the thrombotic challenge in patients with diabetes. GUSTO-IV ACS failed to demonstrate a difference in mortality when used without PCI. The PURSUIT trial provided evidence that eptifibatide decreases death or non-fatal myocardial infarction (MI) in the main group and in the diabetic subgroup. Reductions in this primary endpoint were driven by the reduction in non-fatal MI. The PRISM and PRISM-PLUS trials demonstrated a reduction in death, MI or refractory ischaemia at 48 h or 7 days in the main cohort but not specifically in patients with diabetes. Data supporting use of GP IIb/IIIa inhibitors are inconsistent, raising the question of whether these agents should be used at all without PCI. Variability in experimental methodology of platelet aggregometry and selection of anticoagulant used during dose finding studies may have generated doses that are insufficient to overcome the thrombotic burden. A new marker of active inflammation, sCD40L is found to be upregulated at subtherapeutic doses of GP IIb/IIIa inhibitors, suggesting that rebound inflammatory processes may partially account for absence of clear evidence of benefit with some GP IIb/IIIa inhibitors in patients with diabetes experiencing UA/NSTEMI.

Treatment of hydatid disease of the liver. Evaluation of a UK experience

BACKGROUND

Hydatid disease of the liver though endemic in many countries, is rare in the UK. We evaluated a 16-year experience of treating hydatidosis using a management protocol combining surgery with anti-scolicidals.

PATIENTS AND METHODS

There were 30 patients. 14 (47%) males, median age 41 (range 25-72) years, of whom 21 (70%) were symptomatic. Diagnosis was by serological tests and imaging. All had disease confined to the liver and received peri-operative anti-scolicidal drug therapy.

RESULTS

The initial 4 (13%) patients received praziquantel combined with albendazole for 2 weeks and the following 26 (87%) patients received two cycles of albendazole 400 mg twice daily for 28 days, with a 14-day break in between. However, 2 (7%) patients could not tolerate albendazole, one due to GI side effects and the other developed deranged liver functions. These 2 patients subsequently received praziquantel for 2 weeks. All patients underwent surgery. Subtotal cystectomy was carried out on 29 (96%) patients and 1 patient required a segmentectomy. Cystobiliary communications were identified in 15 (50%) of patients which were oversewn using fine absorbable sutures. Of these, 7 had the bile ducts decompressed using a T tube, with only 1 developing a post-operative bile leak. In comparison, 8 were not drained of which 6 leaked (p = 0.03). The median post-operative hospital stay was 8 days (range 5-24). Patients who developed post-operative bile leaks, however, needed prolonged abdominal drainage for a median of 21 days (range 18-24). Two (7%) patients developed histologically proven recurrent disease. The median follow-up was 56 months (range 3-87).

CONCLUSION

Surgery combined with anti-scolicidal therapy proved effective. Cystobiliary communications are common and, when identified, should result in the biliary system being drained, to avoid post-operative bile leaks.

CT-guided percutaneous punctate midline myelotomy for the treatment of intractable visceral pain: a technical note

Surgical treatment of intractable visceral pain has always been a challenge. The relatively recent discovery of a specific visceral pain pathway brought a new insight to this matter. The authors describe a new technique to interrupt this pathway, the CT-guided percutaneous punctate midline myelotomy, successfully applied in two patients with intractable pelvic visceral pain. Due to its simplicity, safety and high effectiveness, it may become the treatment of choice for intractable visceral pain.

The internal jugular vein valve may have a significant role in the prevention of venous reflux: evidence from live and cadaveric human subjects

INTRODUCTION

The internal jugular vein valve (IJVV), which is situated just above the termination of the internal jugular vein, is the only valve between the heart and the brain. This means that it plays a role in the prevention of cephalad flow of venous blood. If the IJVV is damaged or becomes incompetent, increase in intrapleural pressure could result in raised intracranial pressure. Additionally, the jugular venous pulse (JVP) is used clinically to estimate right atrial pressure, a functional IJVV may prevent accurate estimation of the JVP.

OBJECTIVES

To describe the presence and the competence of the IJVV in post-mortem and live human subjects. DESIGN - setting and methods: The anatomical appearance of the IJVV from 30 cadavers was studied. Competence was checked by measuring maximum hydrostatic pressure before reflux occurred through the valve. The function of the valve was evaluated in 25 live subjects using colour duplex scanning.

RESULTS

The IJVV was present in all cadavers just before its termination (60 IJVVs from 30 subjects). The valve was bicuspid in most cases (93%). The competence of 41 IJVVs was checked of which only three (7%) were found to be incompetent. All IJVVs in live subjects were found to be competent.

CONCLUSION

This study confirms that a functional IJVV is present just above the termination of the internal jugular vein. The IJVV may therefore prevent reflux of venous blood from the right atrium into the internal jugular vein.

Efeito dos Níveis de Cantaxantina na Dieta Sobre o Desempenho e Qualidade dos Ovos de Poedeiras Comerciais

O experimento teve como objetivo estudar os efeitos de níveis de cantaxantina sobre o desempenho e a coloração das gemas dos ovos de galinhas poedeiras. Foram utilizadas 384 galinhas da linhagem Hisex Brown, em um delineamento em blocos ao acaso, contendo seis tratamentos (0, 12, 24, 36, 48 e 60 ppm de cantaxantina), com oito repetições de oito aves por parcela. O período experimental foi de 56 dias. A coleta de ovos foi realizada diariamente e a análise de coloração dos ovos foi efetuada com o abanico colorimétrico da Roche. Durante os 14 dias do período inicial do experimento, a melhor coloração das gemas foi obtida com a adição de 60 ppm de cantaxantina, atingindo-se a cor plateau de 14,3 do leque colorimétrico Roche aos 5,43 dias de inclusão do pigmentante. Considerando-se o período experimental total, os níveis de cantaxantina utilizados melhoraram de forma quadrática a coloração das gemas, sem influenciar os parâmetros produtivos e demais características de qualidade dos ovos de poedeiras comerciais.

[The use of intestinal enema in labor preparation: analysis of advantages and disadvantages]

This study aimed at investigating the effects of intestinal cleansers on fecal contamination during labor and delivery amongst women assisted in a university hospital. The subjects were 90 pregnant women (43 normal births, 27 forceps and 20 caesarean sections). The population was divided in two randomized groups: with and without the use of intestinal cleansers. It was possible to conclude that intestinal cleansers did not provide faster labor and did not reduce fecal contamination. However, the women who had used an intestinal cleanser tended to regard it as positive.

Theoretical evaluation of the origin of the regio- and stereoselectivity in the Diels-Alder reactions of dialkylvinylboranes: studies on the reactions of vinylborane, dimethylvinylborane, and vinyl-9-BBN with trans-piperylene and isoprene

Ab initio and DFT calculations have been performed to study the origin of the regio- and stereoselectivity of the Diels-Alder reactions of dialkylvinylboranes with substituted dienes. B3LYP/6-31G energies of the transition structures for the reactions of dimethylvinylborane and vinyl-9-BBN with trans-piperylene and isoprene yielded calculated ratios which are in very good agreement with experimental values. Nonclassical carbon-boron [4+3] secondary orbital interactions seem to account for the high endo stereoselectivity of these reactions. However, C-B interactions become less important when the bulkiness of the alkyl groups attached to boron increases. Both endo and exo transition structures for the reactions of dimethylvinylborane and vinyl-9-BBN adopt classical [4+2] character. This study also extends Singleton's investigation on butadiene to regioselectivity. FMO theory has been used to rationalize the lack of regioselectivity in the reactions of dimethylvinylborane. The anomalous meta regioselectivity of the Diels-Alder reaction of vinyl-9-BBN with trans-piperylene is mainly caused by steric effects.

Ventricular endocardial right bifocal stimulation in the treatment of severe dilated cardiomyopathy heart failure with wide QRS

The QRS widening by ventricular conventional pacing impairs the systolic and diastolic functions and increases mitral regurgitation. The aim of this study was to compare conventional pacing to an alternative stimulation mode with a narrower QRS using two leads in the RV. Thirty-nine (25 men, 14 women; mean age 60.1 +/- 15.1 years) dilated cardiomyopathy patients (Chagas' disease [n = 17], coronariopathy [n = 9], AV ablation for tachycardiomyopathy [n = 3], and other [n = 10]) with cardiac failure (NYHA 3.1 +/- 0.8), pacemaker indication, and chronic AV block (22 AF) had endocardial pacemaker implantations (27 Biotronik, 12 Guidant). Two RV leads (one septal, one conventional [RV apex] were connected, respectively, to the atrial and ventricular pacemaker plugs. After clinical stabilization they were studied under three stimulation modes in the same session: AAI (septal), VVI (conventional), and ventricular endocardial right bifocal stimulation (VERBS) (DDT/DVI/DDD = AV interval = 15/10 ms). In comparison to conventional pacing, VERBS increased ejection fraction (0.124), cardiac output (19.5%), and peak filling rate (31.0%), and decreased QRS duration (24.7%), left atrium area (11.9%), mitral regurgitation area (32.3%), the diastolic transmitral flow (E/A relation) (19.3%), and the propagation flow time (18.0%) from the mitral valve to the left ventricular apex (tE_col), (P < 0.05). The quality-of-life showed an impressive score reduction of 50.4%. The septal stimulation alone showed a less expressive benefit. In severe dilated cardiomyopathy with classic pacemaker indication, VERBS showed significantly better performance than the septal or the conventional stimulation alone. There was a good systolic and a remarkable diastolic improvement causing an important reduction in the quality-of-life score.

Relation between birth weight and placenta weight

With the goal to establish a model that relates birth weight to placenta weight, adjusted for the most documented predictors of birth weight, 300 live newborns were studied, all were products of single gestation. Inclusion criteria were newborns with gestational age of 37 weeks or older according to the date of last menstruation, whose mothers did not have diabetes mellitus, high blood pressure, pre-eclampsia, or eclampsia. The weight of the newborn was identified from the anthropometry data collected by previously trained nursing personnel in each of the participating hospitals. Immediately after delivery, the placenta was weighed. Multiple linear regression was used to see the effect of placenta weight and each variable on birth weight. The mean of birth weight was 3,369 g with a standard deviation (SD) of 445 g. Placenta weight had a mean of 537 g (SD: 96 g). The relation between the weight of the placenta and the birth weight was significant, and we found that for each gram increase in placenta weight, birth weight is increased by 1.98 g (SE = 0.25, p < 0.01) and this relation is not linear, since the quadratic term is significant. Placenta weight has a nonlinear relation to the birth weight and is an important predictor of birth weight. Together with the gestational age and the maternal age and size, it explains 32% of the variability of birth weight. Placenta weight can be a 'sentinel' indicator of nutritional and/or environmental problems.

Stereological determination of the volume of the rat hemimandible tissues

Rodent incisors are useful models to study the development and behavior of dental and periodontal tissues. Some studies require three-dimensional reconstructions of the tooth but none of the described methods yield actual volumetric data. Unlike the rat lower incisors the hemimandible can be easily isolated and its volume was determined by Cavalieri's geometrical principle. This method associated with point-counting volumetry was used to calculate the volume of the structures found in that bone mainly those related to the lower incisor. For 172 g male rats the mean volume of the hemimandible was 182.7 mm(3), statistically not different from 184.9 mm(3) the mean volume of the same hemimandibles determined by Archimedes' principle. The coefficients of error (CE) of Cavalieri's estimates for the hemimandible, incisor as a whole (the tooth itself, odontogenic region and periodontium) and bone tissue were less than 0.04. For the incisor individual tissues the CEs were usually above 0.05, however their calculated volumes are probably not different from the actual ones. The data for incisors and their periodontal tissues and for bone, because of continuous growth of these structures, are meaningful only for rats of the same gender, strain and weight range.

[Diagnosis of hepatitis C in clinical practice: review of the literature]

The objective of this study was to review the literature concerning laboratory tests to detect hepatitis C virus infection, which have been available since 1989. The diagnosis of hepatitis C is mainly based on serological techniques and on molecular techniques. Serological techniques to detect hepatitis C virus antibodies are the method of choice to identify past or present infection. There are two types of serological assays: highly sensitive enzyme-linked immunosorbent screening assays; and more specific immunoblot techniques, which are used as supplemental or confirmatory tests. With respect to molecular diagnostic techniques, there are several types of assays. One such assay detects viral RNA. It is useful for diagnosis in such situations as the early stages of infection, with immunosuppressed patients, and with persons who have a low probability of infection. Molecular assays are also recommended before treatment with interferon and ribavirin, in order to monitor response to treatment. Other assays allow determination of viral load by either target amplification (as in polymerase chain reaction) or signal amplification (as in branched-DNA). Determining the hepatitis C virus genotype is possible using either molecular techniques or serotyping. Determining viral load and genotype is useful for planning the duration of interferon and ribavirin treatment. There have been major advances in the diagnosis of hepatitis C in the past decade Improvements in the sensitivity and specificity of antibody tests have provided faster, less expensive diagnoses. However, more accurate assays are still needed for such groups as immunosuppressed persons and acute hepatitis patients.

Desempenho de Poedeiras Comerciais Alimentadas com Levedura Seca (Saccharomyces Crevisiae) de Cana-de-Açúcar

Essa pesquisa teve por objetivo avaliar o efeito da adição de levedura seca de álcool (LSA) à dieta de poedeiras. Foram utilizadas 120 poedeiras Isabrown com 33 semanas de idade, distribuídas em um delineamento estatístico de blocos ao acaso, com cinco tratamentos (0, 7, 14, 21 e 28% de levedura), quatro repetições e seis aves por unidade experimental. Rações isoprotéicas (18% PB), isoenergéticas (2.800 kcal EM/kg), isocálcicas (3,8% Ca) e isofosfóricas (0,38% Pd) foram formuladas à base de milho e farelo de soja. Os níveis de LSA não afetaram a produção galinha dia (PGD=94,71± 0,96%), peso dos ovos (PO=64,35± 0,85g), peso médio final das aves (PMF=1.872,07± 50,36g), ganho de peso das aves (GP=-52± 25,84g) e umidade das excretas (UE=75,85± 3,81%). Observou-se efeito quadrático para as variáveis: consumo de ração (CR=117,03-0,34LSA+0,02LSA²) e conversão alimentar por dúzia de ovos (CADO=1,48-0,0025LSA+0,00023LSA²). Efeito linear foi observado para a variável conversão alimentar por massa de ovo (CAMO=1,867+0,0072LSA). A utilização de até 14% de levedura proporcionou desempenho semelhante ao obtido com a dieta à base de milho e farelo de soja. A análise econômica mostrou ser viável a utilização de níveis até 28% de levedura.

[Chagasic infection prevalence in blood donors at the Regional Blood Donation Center of Iguatu]

The objective of this study is to evaluate the frequency of Trypanosoma cruzi infection among blood donors at the Iguatu Regional Hemocenter, CE, 1996 - 1997, using the Enzyme-linked immunosorbent assay (ELISA) and hemagglutination passive reverse (HPR) tests. Of the 3,232 donors analyzed a total of 61 (1.9%) were seropositive for chagasic infection. The greatest number of infected donors was found in the 41-50 year age group, while the majority of donors were in the 18-30 year age group. Of the total number of donors analyzed 2,991 (92.5%) were men and 57 (1.9%) of these were seropositive. In all 1,825 (56.5 %) of the donors were from a rural area. The results showed that the ELISA test detected 49 cases of infection, but HPR only 38, thereby demonstrating that the use of two or more different tests by blood banks prevents transfusion associated Chagas' disease.

Gastroesophageal reflux disease: New oral findings

OBJECTIVE

The objective of this study was to investigate the effects of gastroesophageal reflux disease (GERD) on dentition, salivary function, and oral mucosa.

STUDY DESIGN

Thirty-one patients with esophagitis underwent medical evaluation, which included taking their medical history, performing both an esophagogastroduodenoscopy and esophagus biopsy, and conducting a stomatologic examination. The latter consisted of an extraoral and intraoral physical examination, saliva tests (flow, buffer capacity, and pH), and biopsy and morphometry of the palatal mucosa, as well as taking a history of the patients' habits. Fourteen healthy volunteers from the same population were used as a control group.

RESULTS

No relationship between GERD and changes in the oral cavity was shown by saliva tests, oral clinical examination, or histopathologic examination of the palatal mucosa. However, morphometric analysis of the palatal epithelium showed a statistically significant difference between the patients with GERD and the control group.

CONCLUSIONS

GERD is associated with microscopic alterations in the palatal mucosa (epithelial atrophy and increased fibroblast number), which are only detected by morphometry.

Role of kinins and nitric oxide on the rabbit arthritis induced by Bothrops jararaca venom

The effects of the nitric oxide synthase inhibitor N(omega)Nitro-L-arginine-methyl ester (L-NAME) and of the bradykinin B(2) receptor antagonist HOE 140 were evaluated in the inflammatory reaction induced by Bothrops jararaca venom (BjV) in New Zealand White rabbits. Arthritis was induced by injecting 0.5 ml of a sterile solution of BjV (1-64 microg/ml) into the knee intraarticular cavity. The contralateral joint was injected with bovine serum albumin (BSA) diluted in sterile saline. At selected times thereafter (4, 24 and 48 h), the vascular permeability and the leukocyte influx in both the synovial fluid and synovium were evaluated. BjV caused a dose-dependent increase in both leukocyte influx and protein extravasation which reached a maximal response at 16 microg. Bothrops jararaca venom also induced the increase in the leukocyte accumulation in the synovium and in the concentration of both NO(2)/NO(3) in the synovial fluid. Chronic administration of L-NAME (20 mg/kg/day in the drinking water for 2 weeks) markedly reduced the leukocyte accumulation (90%), protein leakage (44%), and NO(2)/NO(3) (50%) levels in the synovial fluid, measured at the 4th h. Hoe 140, given i.v. (0.3 mg/kg, 30 min before) also reduced leukocyte accumulation (75%), protein leakage (48%), and NO(2)/NO(3) (79%) levels in the synovial fluid, measured at the 4th h. Similar results were obtained with acute administration of L-NAME (30 mg/kg, i.v., 30 min before). These results indicate that arthritis induced by BjV is triggered by kinin formation and that the increase in both vascular permeability and leukocyte accumulation is modulated by NO release.

Superior water maze performance and increase in fear-related behavior in the endothelial nitric oxide synthase-deficient mouse together with monoamine changes in cerebellum and ventral striatum

Nitric oxide (NO) has been implicated in the control of emotion, learning, and memory. We have examined endothelial NO synthase-deficient mice (eNOS-/-) in terms of habituation to an open field, elevated plus-maze behavior, Morris water maze performance, and changes in cerebral monoamines. In the open field, eNOS-/- animals were less active than wild-type controls but showed unimpaired habituation. In the plus-maze, an anxiogenic effect was observed. Proceeding from previous findings of deficits in hippocampal and neocortical long-term potentiation (LTP) in our eNOS-/- mice, we investigated whether these animals also express deficits in learning tasks that have been linked to hippocampal function and LTP. Unexpectedly, eNOS gene disruption led to accelerated place learning in the water maze. Furthermore, during long-term retention and reversal learning, eNOS-/- mice showed improved performance. In a cued version of the water maze task, eNOS-/- and control mice did not differ, implying that the superior performance of eNOS-/- animals on the former tasks cannot be attributed solely to differences in sensorimotor capacities. The neurochemical evaluation of the eNOS-/- mice revealed increases in the concentrations of the serotonin metabolite 5-HIAA in the cerebellum, together with an accelerated serotonin turnover in the frontal cortex. Furthermore, eNOS-/- mice had a higher dopamine turnover in the ventral striatum. These findings are discussed in terms of possible concomitant effects on physiological parameters, such as a decreased reactivity of GABAergic neurotransmission or changes in vascular functions, and effects on behavioral processes related to reinforcement, learning, and emotion.