Hypothermia on admission: a risk factor for death in newborns referred to the Pernambuco Institute of Mother and Child Health

The objective of this study was to determine the mortality risk related to hypothermia at the moment of admission and other factors such as clinical and geographical related to the transportation of the newborns admitted to the Instituto Materno Infantil de Pernambuco IMIP from 8 March to 11 June 2000. A prospective study involving 320 newborns arriving from home or health centres was carried out. Babies that were dead on arrival or subsequently transferred to other units were excluded. The risk of death was determined according to exposure to hypothermia and other types of exposure, using logistical regression. The risk of death was higher (RR = 3.09; CI = 2.15-4.43) in the group exposed to moderate hypothermia (temperature between 32.5 degrees C and 35.99 degrees C) than in the non-exposed group (temperature equal to or greater than 36.00 degrees C). The relative risk of death was also higher for newborns with a weight of less than 2500 g, that were less than 1 day old, respiratory distress syndrome, premature babies or with congenital malformations, that had used oxygen and/or intravenous infusion during transit, that came from the interior and that had travelled more than 150 km. In the final result of the multivariate analysis, sepsis ('adjusted' RO = 6.23; 95% CI = 5.66-6.80), respiratory distress syndrome ('adjusted' RO = 5.28; 95% CI = 5.03-5.59), moderate hypothermia ('adjusted' RO = 3.49, 95% CI = 3.18-3.81), and distance undertaken greater than 50 km ('adjusted' RO = 2.39; 95% CI = 2.14-2.63) remained. Hypothermia on admission showed itself to be an important and independent risk factor for neonatal death.     

Delta opioid antagonist effects of buprenorphine in rhesus monkeys

Buprenorphine is an opioid with high affinity for delta, mu and kappa opioid receptors. The delta receptor-mediated effects of buprenorphine have not been studied. Thus, the present study examined the delta receptor-mediated effects of buprenorphine in rhesus monkeys. assays of receptor binding and agonist-stimulated GTP S binding confirmed that buprenorphine had high affinity for, and low efficacy at, delta receptors. In an assay of schedule-controlled responding for food presentation in four monkeys, buprenorphine produced little effect alone, but it antagonized the effects of the delta agonist SNC80, the mu agonist morphine and the kappa agonist U50,488. Buprenorphine was approximately 30-fold less potent as a delta antagonist than as a mu or kappa antagonist. In three monkeys trained to discriminate SNC80 from saline, buprenorphine alone produced only saline-appropriate responding, and buprenorphine pretreatment antagonized the discriminative stimulus effects of SNC80. In a fourth monkey, buprenorphine produced a partial substitution for SNC80 that could be blocked by the delta-selective antagonist naltrindole but not by the mu-selective antagonist quadazocine. These results indicate that, in rhesus monkeys, buprenorphine has very low efficacy at delta receptors, and that buprenorphine produces delta receptor-mediated effects with lower potency than it produces mu or kappa receptor-mediated effects.     

Dopaminergic retinal cell differentiation in culture: modulation by forskolin and dopamine

We examined the effects of dopamine and cAMP on the differentiation of dopaminergic retinal cells in the chick retina, using an in vitro system and tyrosine hydroxylase immunocytochemistry. Tyrosine hydroxylase-positive cells were detected in cultures prepared from embryonic day 10 retinas. These increased in number as a function of time in vitro and by treatment for 4 days with forskolin. Besides causing a 3.4-fold increase in the tyrosine hydroxylase-positive population, forskolin also caused these cells to developed morphogenetic features of more mature cells. As opposed to forskolin, cultures treated with dopamine exhibited a 55% reduction of the tyrosine hydroxylase-positive cell population, as compared to untreated cultures. Quinpirole was able to mimic the dopamine effect. This dopamine effect could only be blocked by clozapine, whereas raclopride and eticlopride were ineffective. Our results suggest the existence of a narrow window during development when undifferentiated dopaminergic cells are capable of being influenced by specific signals, possibly via cAMP production. The data also indicate that dopamine may act as a regulatory factor limiting the tyrosine hydroxylase-positive population in the retina.     

Recurrence of a nonsense mutation in the conserved domain of SRY in a Brazilian patient with 46,XY gonadal dysgenesis

We tested a female patient with 46,XY karyotype and pure gonadal dysgenesis for the presence of the SRY gene and for mutations within the SRY conserved domain. A point mutation was identified at nucleotide position 209 with respect to the first ATG. The base substitution is a G-->A transition in the first nucleotide of codon 70 which changes a tryptophan (TGG) to a stop codon (TAG). Even though the father was not available for investigation we assumed that it is a de novo mutation, since it probably generates a nonfunctional truncated protein.     

The Steatocrit Test: a semiquantitative method to evaluate the fecal fat excretion--method standardization

The main objective of this study was to introduce among us this technique. In a first step, steatocrit was compared to Van de Kamer test for 30 fecal samples. A significant positive correlation was found. In a second step, a steatocrit value was determined for normal children aged 0 to 72 months. In children from 0 to 3 months of age, no influence was found of diet (whether exclusively maternal milk or artificial one) on steatocrit value. However, upto the age of 3 months a significant and negative correlation was found between age and steatocrit value. Finally, three age groups were identified with different steatocrit values, as follows: 0-1 month, 4.04%; 1-3 months, 1.38%, 3-72 months, 0.29%. Thus the steatocrit test for fecal fat excretion was again shown to be not only simple, rapid, painless and inexpensive but also a reliable one.