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Biomedical subjects

L O'Bryan

Publications and source records attributed to L O'Bryan.

7 recordsLinked to original sources

Trypanosoma cruzi meningoencephalitis in HIV-infected patients.

Five cases of Trypanosoma cruzi meningoencephalitis in HIV-infected patients are reported. All patients presented with mass lesions on head computed tomographic scan, trypanosomes in the cerebrospinal fluid and failure to respond to antitoxoplasmosis therapy. Benznidazole therapy was associated with clinical improvement in 1 patient. Another 4 patients had T cruzi identified in a peripheral smear. T cruzi needs to be considered in the differential diagnosis of HIV-infected patients with central nervous system mass lesions if they have a history of appropriate exposure.

AIDS-Related Opportunistic Infections↗

Outcome of unattended out-of-hospital births in Harlem.

OBJECTIVE: To determine the maternal risk factors and infant outcome for unattended out-of-hospital deliveries brought to an inner-city public hospital. METHODS: We compared 59 infants born alive out of hospital during 1989 with 151 randomly selected in-hospital live births, all with birth weight greater than 500 g. RESULTS: History of cocaine use during pregnancy (odds ratio [OR], 4.20; 95% confidence interval [CI], 1.68 to 10.5) and lack of Medicaid or other health insurance (OR, 2.15; 95% CI, 1.04 to 4.45) were independently associated with out-of-hospital delivery. Out-of-hospital delivery was associated with hypothermia (defined as admission axillary temperature < 35 degrees C; OR, 20.8; 95% CI, 4.81 to 89.9) and with hypoglycemia (defined as admission glucose reagent strip reading < 2.2 mmol/L [< 40 mg/dL]; OR, 4.41; 95% CI, 1.29 to 15.1) in separate analyses controlling for birth weight and other risk factors. Polycythemia (venous or arterial hematocrit > 0.65 at age > or = 6 hours) occurred in 14% (eight of 59) of out-of-hospital births. The increased neonatal mortality rate for infants born out of hospital (20.3 vs 7.3 per 1000 live births; OR, 2.82; 95% CI, 1.23 to 6.47) was due to an excess of infants weighing 500 to 999 g. CONCLUSIONS: Unattended out-of-hospital births result in increased neonatal morbidity that may be partly preventable by simple interventions used routinely at inhospital deliveries.

Adult↗

Prohormone processing in Xenopus oocytes: characterization of cleavage signals and cleavage enzymes.

In this study, we characterize the sequences required for the cleavage of prohormones in Xenopus oocytes. We demonstrate that the yeast alpha-factor and the Aplysia egg-laying hormone (ELH) precursors are not cleaved in oocytes following simple pairs of basic residues, such as Lys-Arg, but that the ELH precursor is cleaved following the consensus sequence Arg-Xaa-(Lys/Arg)-Arg. This motif is conserved among precursors that are cleaved in virtually all mammalian cell types. Mutations that generate this sequence in the alpha-factor prohormone also result in efficient processing within oocytes. Cleavage at this consensus sequence may be due to the action of the Xenopus homologues of mammalian furin.

Amino Acid Sequence↗

Intestinal dysmotility syndromes in the elderly: measurement of orocecal transit time.

Altered bowel habits are common symptoms in the elderly, yet the pathophysiology of age-related gastrointestinal dysmotility syndromes is poorly understood. The present study was designed to correlate changes in orocecal transit time (TT) in healthy elderly subjects with or without gastrointestinal dysmotility complaints. Twenty-two geriatric facility resident volunteers, mean age 82 yr (range 65-94 yr) participated, of whom 16 had gastrointestinal dysmotility symptoms. Orocecal TT in the elderly subjects did not differ from that in younger adult controls (100 +/- 11 min vs 93 +/- 20 min). However, orocecal TT was longer in geriatric females (112 +/- 14 min) than in males (70 +/- 6 min, p less than 0.01). We conclude that age alone does not prolong orocecal TT, except when dysmotility symptoms have been present for a prolonged period.

Aged↗

Orally administered kappa as well as mu opiate agonists delay gastrointestinal transit time in the guinea pig.

When an orally administered opiate agonist is systemically bioavailable, the relative activity of that opioid in delaying gastrointestinal transit (GIT) depends on its relative action at central and peripheral sites. This in turn depends on the density of opioid receptor specific subtypes at those sites of action in the species under study. In rats the kappa selective agonist U-50,488H has no effect on GIT. We have found that this same agonist is equipotent to mu agonists morphine and 1-methadone in delaying the orocecal transit of a charcoal meal when administered orally to guinea pigs. Thus, both kappa as well as mu receptor subtypes are involved in the mechanisms of opiate induced slowing of GIT in the guinea pig in contrast to the rat. Interspecies differences must be considered when determining the contribution of opiate receptor subtypes to the mechanisms of opiate-induced constipation.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗