Maternal factors associated with perinatal HIV-1 transmission: the French Cohort Study: 7 years of follow-up observation. The French Pediatric HIV Infection Study Group

The effects of pretreatment with inducers of hepatic cytochrome P450 isoenzymes (phenobarbital, dexamethasone and beta-naphthoflavone) on the metabolism of d-fenfluramine (d-F) and its acute and long-lasting indole-depleting effects were studied in rats, in an effort to obtain further information on the importance of hepatic drug metabolism in relation to its neurochemical actions. Twenty-four hours after the last dose of each inducer, rats were injected with d-F hydrochloride (5 mg/kg, IP) and killed at various times thereafter for parallel determination of indoles and drug concentrations in plasma and brain. Additional rats were treated as above and killed 1 week after d-F hydrochloride (5 and 10 mg/kg) to study the recovery of indole in the cortex, a particularly sensitive brain area. Phenobarbital and beta-naphthoflavone and, to a lesser degree, dexamethasone, stimulated the metabolism of d-F, as evidenced by a decrease in plasma and brain areas under the curve (AUC) compared to vehicle-treated rats. This indicated that multiple isoenzymes are capable of mediating the drug's metabolism, primarily by N-dealkylation to d-norfenfluramine (d-NF). None of the inducers raised plasma and brain AUC of the nor-derivative, and in fact phenobarbital and particularly beta-naphthoflavone reduced it. These different effects were even apparent in rats given d-NF (2.5 mg/kg), indicating that both phenobarbital and beta-naphthoflavone also stimulate the sequential metabolism of the nor-metabolite (by N-deamintaion) which, however, is apparently enhanced most actively by beta-naphthoflavone-inducible forms of P-450.(ABSTRACT TRUNCATED AT 250 WORDS)     

Determination of selenium in serum by hydride generation atomic absorption spectrometry for calculation of daily dietary intake

Hydride generation atomic absorption spectrometry was used to determine the selenium concentrations in 130 samples of human serum from a control group of inhabitants in the southern part of the province of Granada (Spain). The mean selenium concentration in serum was 74.9 micrograms/l. This concentration did not vary significantly (P > 0.05) in relation to the sex of the subject, with concentrations of 80.6 micrograms/l in men and 70.7 micrograms/l in women. These mean values correspond to a mean daily dietary selenium intake of 50.4 micrograms per day in men and 44.6 micrograms per day in women. A considerable number of the individuals in the study area therefore have a daily selenium intake lower than the recommended dietary allowance of 70 micrograms per day for men and 55 micrograms per day for women. Likewise, the measured selenium concentrations in the basic health zones of the area were not statistically different (P > 0.05). The differences in selenium concentration between subjects in coastal zones and mountainous zones are therefore not significant.     

Sources of interracial variation in bone mineral density

Many studies have demonstrated significant differences in bone mineral density between various racial groups. Although it has been suggested that differences in body weight contribute to such interracial variation, the artifactual effect of the skeletal size inherent in projectional absorptiometry methods has been largely ignored. We have measured bone mineral density by dual-energy X-ray absorptiometry in the lumbar spine and at three femoral sites in 200 premenopausal women of Chinese, Indian, European, or Polynesian origin (50 of similar mean age in each group). In the Chinese and Indian women the measured bone mineral density measurements (g/cm2) were similar, but significantly less, at all sites, than those of European women (p < or = 0.005). The European women were, however, significantly taller than both the Chinese and Indian women (p < 0.0001), and when the scale artifact of absorptiometry was removed by dividing the measured bone mineral density either by the height of the subject, or by the square root of the area over which the X-ray beam was projected, then the differences in mean bone mineral density between the Chinese, Indian, and European women were almost completely eliminated. The Polynesian women were significantly more obese (as judged from mean body mass index) than all the other groups (p < 0.0001) and had significantly greater bone mineral density at all sites than all the other groups both before (p < 0.0001) and after (p < 0.0001) correcting for the scale artifact.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of rheological and mucoadhesive properties of three grades of chitosan hydrochloride

In the present study the rheological and mucoadhesive properties of three viscosity grades of a cationic polymer, chitosan, were investigated to assess the suitability of this polymer for gastroadhesive formulations. The influence of the pH, ionic strength and temperature of the hydration medium on the rheological properties was studied. The mucoadhesive performance was assessed in vitro by means of rheological synergism and tensile stress testing. A correlation was found between rheological synergism and tensile parameters (force of detachment and work of adhesion), which proves that both methods can correctly predict the mucoadhesive performance of the polymers examined. It was found that the interaction of chitosan with mucin decreases on increasing molecular weight.     

Santolindiacetylene, a polyacetylene derivative isolated from the essential oil of Santolina canescens

The yield, composition, and some pharmacological activities (hepatoprotective and antioxidant) of the essential oil of Santolina canescens aerial parts have been investigated. The essential oil qualitative data were determined by gc and gc-ms. The main component, santolindiacetylene [1], was isolated and characterized by spectral methods, and the structure assigned as 1-(2'-naphthyl)hexa-2,4-diyne. The protective activities of the essential oil and its main component [1] were evaluated against carbon tetrachloride-induced hepatotoxicity in a rat model. In both cases a significant hepatoprotective effect was observed, as evident from the strong decrease of elevated GPT serum levels caused by carbon tetrachloride-induced hepatic damage.     

A histochemical study of the biological effects of sodium dodecyl sulfate on the intestine of the gilthead seabream, Sparus aurata L

Infantile myofibromatosis (IMF) is a distinct clinicopathologic entity characterized by solitary or multicentric tumors present at birth or in early infancy with a typical biphasic (central hemangiopericytoma-like, peripheral leiomyoma-like) histologic pattern. We present a case of IMF in two siblings with onset of disease in late childhood. Histology of the primary as well as several later tumors was characterized by a monophasic cellular appearance with a prominence of tiny capillaries initially suggesting an unusual vascular tumor. Diagnosis was established by the development of more characteristic biphasic lesions during the course of disease. Immunocytochemistry (Ulex, factor VIII, JC/70A [CD31], PAL-E, BMA120, EN4, QBEnd10 [CD34], SMS actin) and ultrastructural studies showed no (marked) differences between different types of IMF. The monophasic cellular pattern should be recognized as an unusual histologic manifestation of IMF, in particular in patients outside the classical setting or presentation.