[Changes in brain serotonin biosynthesis in rats with diabetes mellitus induced by streptozocin: effect of insulin treatment]. / Cambios en la biosíntesis de serotonina cerebral en ratas con diabetes mellitus inducida por estreptozotocina: efecto del tratamiento con insulina.

OBJECTIVE: To investigate if the changes in the activity of the tryptophan-5-hydroxylase and in brain serotonin synthesis provoked by diabetes mellitus persist or return to normal in the diabetic rats submitted to treatment with insulin. METHODS: Diabetes induced by the administration of streptozotocin in rats and their treatment with insulin was the paradigm used. At days 7, 14 and 21 of evolution, the brain serotonergic biosynthetic activity was evaluated. RESULTS: The diabetic rats showed a significant decrease of body weight. Also, they showed a low concentration of I-tryptophan, as well as a diminution in the activity of the key enzyme tryptophan-5-hydroxylase and its product serotonin in the cerebral cortex and brainstem. Interestingly, the activity of the enzyme was higher in the brainstem from day 14, accompanied with an elevation of the neurotransmitter. The diabetic rats submitted to treatment with insulin showed a complete physical recovery and a return to normal of plasma and brain I-tryptophan. The activity of the enzyme not only normalized but was elevated and with an increase of serotonin in the brainstem and cerebral cortex. CONCLUSION: The present findings confirm that diabetes mellitus produced a chronic anabolic deficit and a decrease in some brain regions of serotonin synthesis. Also, demonstrate that the diabetic rats under specific treatment with insulin had a complete physical recovery and a return to normal of the serotonin precursor in the blood and brain. However, the activity of the limiting enzyme TrpOH case was elevated with an increase of the neurotransmitter in all regions studied. Since the diabetic animal, insulin treated, does recover metabolically, the mechanism of activation of the serotonin biosynthetic path in the brain may not be dependent on the decreased availability of its precursor the free plasma I-tryptophan. Instead, it might be due to a change in the kinetics of tryptophan-5-hydroxylase, since its activity remains significantly increased in spite of plasma and brain normalization of its substrate. Altogether these changes in the biosynthesis of an important brain neurotransmitter may be of relevance in the pathophysiology of the psychoneurological complications in diabetic patients.

[Changes in cerebra serotonin synthesis induced by insulin-dependent diabetes mellitus]. / Alteraciones en la síntesis de serotonina cerebral inducidas por diabetes mellitus insulino-dependiente.

OBJECTIVE: Evaluate if the rats with diabetes mellitus insulin-dependent have a minor activity of the serotonergic biosynthetic pathway through the decrease of the free fraction of L-tryptophan in plasma. METHODS: Diabetes mellitus was induced in rats, and the brain serotonergic biosynthetic activity was evaluated at 7, 14, and 21 days after streptozotocin administration. RESULTS: The diabetic animals showed a general decrease in body weight. In plasma they had a decrease in the free fraction of L-tryptophan. Also, in the brain they show low levels of the amino acid, as well as decrease of the activity of the limiting enzyme tryptophan-5-hydroxylase and its product serotonin. Interestingly, the activity of the enzyme was higher in the brainstem from day 14, accompanied with an elevation of the neurotransmitter. CONCLUSIONS: The results confirm that diabetes mellitus insulin-depend induce chronic undernourishment. The low levels of L-tryptophan in blood of the diabetic animals suggest a minor transport of the amino acid to the brain and a decrease in serotonin synthesis, in cerebral cortex and hypothalamus. Besides, during the evolution of the disease, the activity of tryptophan hydroxylase was elevated, independently of L-tryptophan concentration in the brainstem of diabetic animals, suggesting a different response according to the brain region and possibly a different functional change, accompanied by an increase in the synthesis of the neurotransmitter.

Evaluacion en neonatos de la administracion de calcio durante la transfusion de recambio. / Evaluation in newborn children of calcium administration during exchange transfusion

Para demostrar que la frecuencia de hipocalcemia clinica y quimica es similar con administracion de gluconato de calcio (GCa) o sin ella, se estudiaron 40 neonatos de termino sometidos a transfusion de recambio (TR) por isoinmunizacion ABO y Rh. A 20 se les administro GCa durante la TR por cada 100 ml de sangre recambiada, y a los 20 restantes no se les aplico. Se les cuantifico el calcio serico total y ultrafiltrable previo a la TR a los 100, 200, 300 y 400 ml de sangre recambiada y seis horas despues, y se busco durante todo el procedimiento la presencia de signos clinicos de hipocalcemia. Se encontro que ningun neonato del grupo con GCa o sin el manifesto hipocalcemia clinica, y que la frecuencia de hipocalcemia quimica con calcio total < 8 mg/dl y ultrafiltrable < 5 mg/dl fue estadisticamente similar en ambos grupos.Al final se mencionan las hipotesis que explican la ausencia de hipocalcemia clinica sin administrar calcio, y se recomienda no aplicarlo en neonatos de termino que requieran TR por sus peligros potenciales

Correccion del desequilibrio hidroelectrolitico mediante la rehidratacion por via oral. / Correction of water-electrolyte imbalance by oral fluid therapy

Se analizaron 250 pacientes que ingresaron en un lapso de tres meses al Servicio de Urgencias del CMN, IMSS, deshidratados por gastroenteritis que fueron rehidratados por via oral, con el objeto de evaluar la correcion de las alteraciones electroliticas y la capacidad de las madres para administrar el tratamiento. La edad de los pacientes fue en promedio de 7,6 meses (3 dias a 36 m); la diarrea de 4.1 dias y 83% presentaban vomito, 65% presentaban desnutricion de grado variable y la deshidratacion fue en promedio de 5.5% en todo el grupo. Los resultados en las muestras sanguineas tomadas previamente al tratamiento y despues de corrigida la deshidratacion demostraron que las alteraciones del sodio en los pacientes hipo e hipernatremicos tienen a la correccion. De la misma manera sucedio con las alteraciones del potasio serico, con la acidosis y la uremia. No hubo diferencia para corregir adecuadamente el desequilibrio entre los recien nacidos y los desnutridos con los ninos de mayor edad y peso normal. Diarrea aguda, hidratacion por via oral

[Subdural empyema due to Salmonella typhimurium. Analysis of a case]. / Empiema subdural por Salmonella typhimurium. Análisis de un caso.

The case was that of an infant with congenital hydrocephalus who developed subdural empyema. The most outstanding items were, the age of the patient (18 months), the identification of Salmonella typhimurium, a germ rarely described responsible for this pathology, the absence of anacrobe germs and the possible hematogenous dissemination from the digestive tract when the port of entry usually associated is the infection of the paranasal sinuses. The most useful method for study was the computerized axial tomography.