Chronic administration of leptin into the lateral ventricle induces sexual maturation in severely food-restricted female rats

Experimental traumatic brain injury (TBI) damages cerebral vascular endothelium and reduces cerebral blood flow (CBF). The nitric oxide synthase (NOS) substrate, L-arginine, prevents CBF reductions after TBI, but the mechanism is not known. This study examined the possibility that post-traumatic hypoperfusion is due to reductions in the substrate sensitivity of NOS which are overcome by L-arginine. Isoflurane-anesthetized rats were prepared for TBI (midline fluid-percussion, 2.2 atm), sham-TBI, or no surgery (control), and were decapitated 30 min after injury or sham injury. The brains were removed and homogenized or minced for measurements of crude soluble or cell-dependent stimulated NOS activity, respectively. Baseline arterial oxygen, carbon dioxide, pH, or hemoglobin levels did not differ among control, sham, or TBI groups. Total cortical soluble NOS activity in TBI-treated rats was not significantly different from either untreated or sham groups when 0.45 microM or 1.5 microM L-arginine was added. Also, there were no differences in cell-dependent NOS activity among the three groups stimulated by 300 microM N-methyl-D-aspartate, 50 mM K+, or 10 microM ionomycin. These data suggest that TBI reduces CBF by a mechanism other than altering the substrate specificity or activation of nNOS.     

Anterior opercular syndrome, caused by herpes simplex encephalitis

Bilateral frontal and parietal opercular lesions cause a syndrome characterized by paralysis of the masticatory, facial, pharyngeal, and tongue muscles (the anterior opercular syndrome). The anterior opercular syndrome can occur in patients with herpes simplex encephalitis (HSE), but in most of these patients the diagnosis of HSE was not confirmed. We describe the anterior opercular syndrome in four patients with HSE. In two of these patients, the anterior opercular syndrome dominated the clinical picture, but in the other two patients it was overshadowed by other manifestations of HSE. The diagnosis of HSE was confirmed by detection of herpes simplex virus (HSV) DNA in the CSF (two patients), culture of the HSV from a brain biopsy (one patient), and elevated HSV antibody titers in the CSF (one patient). Our patients made a partial recovery. Acute onset of weakness of masticatory, facial, pharyngeal, and glossal muscles, accompanied by fever, headache, and partial motor seizures of the face should suggest HSE.     

The individual characteristics of 90Sr accumulation in the body of 2 species of the common vole inhabiting the territory of the eastern Urals radioactive trace

Individual peculiarities of 90Sr skeleton deposition in voles M. gregalis and M. arvalis inhabiting at the territory of East Ural Radioactive Trace were investigated. More high accumulation of radionuclide in the organism of M. gregalis was registered. Considerable variations (3-6 times more, than in linear mice ones) of individual indices of radionuclide accumulation exceeding interspecies level are found. Possible reasons of both interspecies differences and an individual deposition' variability were discussed.     

Birth order, estrogens and sex-ratio adaptation in African wild dogs (Lycaon pictus)

Because the sex of mammals is chromosomally determined, populations generally produce a similar proportion of males and females. However, it has been recognized for more than century that individuals might increase their fitness by over-producing offspring of one sex, under certain conditions. Small biases in the secondary sex ratio are seen in many vertebrates. Here, we report that the sex ratio of primiparous African wild dogs (Lycaon pictus) is strongly biased in favor of sons (63%), while multiparous females produce an excess of daughters (64%). The direction of these biases is predicted by individual females' need for subordinate helpers. For humans, elevated estrogens have been hypothesized to bias the secondary sex ratio toward males. Consistent with this hypothesis, primiparous female wild dogs had basal estrogen levels double those of multiparous females.     

The effects of incremental submaximal exercise on circulating leukocytes in physically active and sedentary males and females

The presence of HIV-1 DNA sequence variants of pediatric AIDS patients was investigated in a two-stage polymerase chain reaction (PCR) using nested primers for the first and second (V1-V2) hypervariable regions of the proviral envelope (gp 120) gene (env1). Gel electrophoresis analysis yielded amplified DNA bands which exhibited length variations which were characteristic for each child. The PCR products were cloned and the resulting clones demonstrated inserts of different lengths in a patient and between patients. Analysis of five clones from two different patients at the level of DNA sequencing indicates an extreme heterogeneity in the V1-V2 region. DNA maximum similarity between all of the isolated clones ranged between 69 to 96%. Comparison between DNA sequences of the isolated clones and HIV-1 strains of other parts of the world was also performed. The highest percentage of similarity that was found with known HIV variants included the following strains: HIVADA, HIVJFL, HIVSW42, HIVSWB83, HIVTRA2, HIVWMJ22. The sequences also showed a high degree of similarity to the clade B virus HIVSF162. The analyzed HIV-1 sequences demonstrated the expected high degree of variation in the V1-V2 region of the envelope gene and in some cases that the variation between isolates from the same patient may exceed the variation between the individual clones and the reference HIV-1 strains.     

Naloxone attenuates serum corticosterone and augments serum glucose concentrations in broilers stimulated with adrenocorticotropin

The effects of exogenous naloxone and adrenocorticotropin (ACTH) on circulating concentrations of corticosterone and glucose in broilers were determined. Birds were injected i.m. at 0 and 2 h with either saline or naloxone, then i.v. at 2.5 h with either saline or ACTH. Control birds received saline at each injection. Blood samples were taken before the experiment started (0 min) and 30, 60, and 90 min after the last injection. Intramuscular injections of naloxone significantly reduced subsequent ACTH-stimulated increases in serum corticosterone; however, when followed by saline, naloxone elevated corticosterone by 90 min after the final injection of saline. Glucose levels were significantly elevated at 60 min in birds receiving ACTH i.v., but remained elevated through 90 min in birds pretreated with naloxone. Naloxone pretreatment attenuated serum corticosterone but augmented serum glucose concentrations in ACTH-stimulated broilers.