Long-term Impairment of Acquisition of a Spatial Memory Task following Isoflurane-Nitrous Oxide Anesthesia in Rats

Background: The authors demonstrated previously that isoflurane-nitrous oxide anesthesia attenuates performance improvement on an already-learned spatial memory task and that the effect persists for weeks. This experiment was designed to test the hypothesis that learning of new information is particularly susceptible to prolonged disruption after general anesthesia.

Methods: Six- (n = 5) and 20- (n = 5) month-old male Fischer 344 rats were anesthetized for 2 h with 1.2% isoflurane, 70% nitrous oxide, and 30% oxygen. Age-matched control rats received 30% oxygen and 70% nitrogen (n = 5 per group). Rats breathed spontaneously, and anesthetic and oxygen concentrations were measured. Spatial learning was assessed daily for 21 days on a 12-arm radial maze (RAM) beginning 48 h after anesthesia. In a post hoc experiment to examine locomotion, swim speed was assessed in a separate group of identically treated rats (n = 3 per group) for 4 days beginning 48 h after anesthesia.

Results: Aged rats were slower to complete the maze, made fewer correct choices before first error, and made more errors at baseline than young rats (P < 0.05). Anesthesia worsened maze performance in both age groups, as evidenced by increased time to complete the maze and a decreased number of correct choices before first error (P < 0.05), but there were no statistically significant differences in total number of errors. Interestingly, there were no age-by-anesthesia interactions. Aged rats swam slower than adult rats (P < 0.001), but there were no differences between the control and anesthesia groups.     

Trends in avoidable causes of infant mortality in Belo Horizonte, Brazil, 1984 to 1998

OBJECTIVE: To analyze the infant mortality trend in a metropolitan area, from 1984 to 1998. The main focus was on avoidable causes of neonatal and post-neonatal mortality. METHODS: Sources of data were the Sistema de Informacoes em Mortalidade do Ministerio da Saude (SIM-MS) [Mortality Information System of the Ministry of Health] and Fundacao Instituto Brasileiro de Geografia e Estatistica (IBGE) [Brazilian Institute of Geography and Statistics Foundation] (official live birth and death records) for the metropolitan region of Belo Horizonte, in the State of Minas Gerais. A simple linear regression model was used to evaluate time-trends of mortality rates. Statistical significance of the inclination of the regression curves was considered for the p<0.05 level. RESULTS: During the 15 year period in question, the infant mortality rate declined from 48.5 to 22.1/1,000 live births. However, the most accentuated decrease was observed during the last four years of the study period. The post-neonatal group was greatly responsible for this decline both in the capital and in the other districts within the metropolitan region of Belo Horizonte. CONCLUSIONS: Although a significant decrease in the infant mortality rate has been observed, particularly in the post-neonatal mortality, it is still larger than the rates found in developed countries. Deaths due to perinatal morbidities as well as the group of causes represented by diarrhea-pneumonia-malnutrition still present an important potential for reduction. The authors discuss the role of the health services in improving the rates of these avoidable causes of infant mortality.     

Providers' compliance with the balanced counseling strategy in Guatemala

The balanced counseling strategy developed in Peru improved family planning care and clients' knowledge of their contraceptive method choice, but few providers adopted it. To expand its use, an algorithm was introduced and training, job aids, and reinforcement were supplied to Ministry of Health providers, most of whom were paraprofessionals, from two areas (40 clinics) in Guatemala. Mystery clients made pretest and post-test visits to these clinics and to providers from a nonequivalent control group (40 clinics). The results showed that the strategy was used in 85 percent of the controlled consultations at the experimental clinics. Use of the strategy improved quality of care regardless of the provider's performance at baseline and regardless of ethnic or regional differences. Counseling session length increased by nine minutes, but real-client load did not change. Guatemalan clients can be expected to benefit from the strategy. The increased session length has not yet caused problems, but it may pose policy dilemmas in the future.     

Liver transplantation: teaching strategies used with patients waiting for surgery

This study aims to describe the learning results of the implementation of teaching strategies involving patients who will be submitted to liver transplantation. One of these strategies is to give the patients a manual with orientations and the subsequent application of a questionnaire related to the content of the manual. Authors analyzed 13 patients who were waiting for liver transplantation. With respect to the answers regarding the questionnaire, an average of 83.8% of correct responses was given and only one patient got all the questions right. During the correction and the time to clarify their doubts, authors concluded that the opportunity of reading the manual and applying the questionnaire allowed patients and families to get a better understanding about the surgery's most important aspects.     

Extra-adrenal pheochromocytoma: update of the most controversial features. Apropos of two cases

Pheochromocytomas are uncommon neuroendocrine tumors. They are usually symptomatic and sporadic and are generally located in the adrenal medulla. We present two cases of extra-adrenal nonfunctional pheochromocytomas located in the retroperitoneum. The tumors were apparently benign and sporadic and were not associated with other neoplasms or hereditary diseases. Ultrasonography, computed axial tomography and magnetic resonance imaging were performed before complete excision of the tumors using open abdominal surgery. Several immunohistochemical techniques were performed to reach the definitive diagnosis. After 8 and 14 months of follow-up, there is no evidence of recurrence or other syndromes. As a consequence of these two cases, we performed a review of the literature on the topic, focussing on the most controversial areas.