Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems

Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 +/- 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10(-6)-10(-4) M) of kainic acid (10(-8)-10(-6) M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10(-4) M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not by electrical stimulation. The addition of GABA (10(-5)-10(-3) M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10(-6)-10(-4) M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation.     

Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

Noninvasive Nasal Mask BiPAP Management for Prolonged Respiratory Failure Following Cardiovascular Surgery

A bstract The purpose of this study was to assess the efficacy of nasal mask bi-level positive airway pressure (BiPAP) support in managing respiratory failure following cardiovascular surgery. A total of 20 patients requiring postoperative prolonged respiratory support of 72 hours or longer were studied. BiPAP support was used for eight patients (BiPAP group); the other 12 patients were managed using ordinary oxygen mask treatment (control group). The mean age of the BiPAP group and control group was 65 and 58 years of age, respectively. The mean period of postoperative endotracheal intubation of the BiPAP group and control group was 12 ± 5 days and 7 ± 1 days, respectively. Reintubation was necessary in two patients of the control group. The BiPAP group patients required no reintubation. BiPAP support was discontinued within 48 hours in 6 out of 8 patients. The respiratory rates of control group increased (p < 0.1) 24 hours after extubation, however, the respiratory rates of the BiPAP group remained unchanged. The values of the respiratory index of the BiPAP group improved significantly (p < 0.01) after BiPAP management (from 1.5 ± 0.2 to 0.9 ± 0.2). The values of the control group, however, remained unchanged. A-aDO₂ and Qs/Qt decreased (p < 0.1) in the BiPAP group. There were no significant differences in central venous pressure or circulatory status between the two groups. In conclusion, BiPAP support is a noninvasive management technique for postoperative respiratory failure and may also prevent prolonged endotracheal intubation.     

Gender and health in Brazil: considerations based on the National Household Sampling Survey]

As in the principal industrial countries, Brazilian women have lived longer than men. However, paradoxically, women present higher morbidity indicators than men. Knowledge of the Brazilian pattern regarding this matter could be a useful contribution to an understanding of their determinants in our specific reality, as well as enabling us to foresee future trends that would make it possible to plan adjustment in the health system. A morbidity study based on data from the National Household Sample Survey (PNAD/IBGE), was undertaken in ten Brazilian states in 1986 with this in view. Coefficients of the prevalence of perceived morbidity, demand for and utilization of health services according to sex, standardized by age and using the direct method, were built up. As a measurement of the differentials, sex ratios were calculated. The excess of perceived morbidity in women was constant in all the regions. The sex differential in the utilization of health services showed regional variations, suggesting a relationship with the health services supply. Sex differentials were not observed in childhood; the highest values were found during the woman's reproductive period, decreasing sharply after 60 years of age. The pattern is very similar in all regions. In the present study, the findings could be partially explained by the methodology adopted, but they are similar to the findings reported in other countries. The intense transformations in the reproductive pattern and in the social status of Brazilian women probably have a considerable impact on the health status and on the recourse to health services, not as yet evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Leakage of 4 resin-based root-canal sealers used with a single-cone technique.

OBJECTIVE: The aim of this study was to measure leakage of 4 resin-based sealers. STUDY DESIGN: Four groups of premolars (n = 60) were prepared using GT Rotary files and the crown-down technique and filled by the single-cone technique with AH26, AHPlus, EndoREZ, and an experimental MBP as sealer. Leakage was measured using the fluid filtration method after 15, 30, and 60 days and determined as microL/min(-1) x 10 psi. RESULTS: Statistical analysis by ANOVA and Tukey HSD test indicated that root fillings with AH Plus and the MBP showed lower leakage values after 15 days (P < .05). At 30 days, AH26 presented higher leakage values when compared to other sealers (P < .05). At 60 days, MBP and AH Plus presented the lower leakage values, differing significantly from EndoREZ (P < .05). CONCLUSION: It was observed that AH Plus and the experimental MBP showed lower leakage after 60 days than AH 26 and EndoREZ.     

Selenium-vitamin E responsive myopathy in farmed ostriches (Struthio camelus) in Botswana.

Four adult ostriches developed sudden onset paresis and were unable to stand up when disturbed. After treatment with selenium and vitamin E, one of the birds could stand and move normally. The others died and post mortem examination revealed pale patches in the thigh muscles. Histopathological examination showed degeneration of skeletal muscles as seen in nutritional myopathy. Serum selenium and vitamin E levels were low whereas aspartate aminotransferase and creatine kinase levels were very high. All remaining birds on the farm were given multimineral and vitamin E supplement and no more cases were seen.