Search PubMed⌕ Search

Biomedical subjects

R C Brown

Publications and source records attributed to R C Brown.

312 records · Page 18Linked to original sources
PubMedDate not supplied

The use and physical effects of intravaginal substances in Zairian women.

Women in Kananga, Zaire, sometimes insert substances into the vagina to enhance sexual pleasure. The objective of this study was to ascertain: 1) what intravaginal substances are used, 2) the prevalence and frequency of their use, and 3) the visible effects they produce on the female genitalia. Focus group discussions with women and men were conducted, and both prostitutes and non-prostitutes were interviewed individually about their sexual preferences and practices. The cervices and vaginae of eight women were inspected and photographed before and after the insertion of commonly used substances. It was found that Kananga residents preferred a "dry-tight" vagina during coitus. They named thirty substances (leaves and powders) that women insert to produce this sensation. Twenty-one of 50 prostitutes (42%), and 17 of 49 non-prostitutes (35%), had used such intravaginal substances. Inspection of the genitalia showed that five different leaves produced inflammatory reactions that lasted up to a week. These genital irritations might facilitate the transmission of pathogenic organisms. Investigators elsewhere should study the use of intravaginal substances and their relationship to sexually transmitted diseases.

Administration, Intravaginal↗
PubMedDate not supplied

Structure, function and regulation of the mitochondrial peripheral-type benzodiazepine receptor.

Steroid biosynthesis begins with the transfer of cholesterol from intracellular stores into mitochondria. Through in vitro and in vivo studies using various steroidogenic cell models and with the help of pharmacological, biochemical, morphological and molecular approaches we demonstrated that the peripheral-type benzodiazepine receptor (PBR) is an 18 kDa mitochondrial protein that interacts with other proteins in the outer mitochondrial membrane to form a multimeric complex. PBR is required for the binding, uptake and release, upon ligand activation, of the substrate cholesterol. Thus, cholesterol becomes available to the inner mitochondrial membrane P450scc where steroid biosynthesis begins. The presence of mitochondrial PBR is also critical in maintaining outer mitochondrial membrane stability and in preventing apoptosis. Considering these functions of PBR and the fact that PBR is a ubiquitous protein, it is suggested that this drug receptor may serve as a target to control various mitochondrial and cell functions and to protect against experimentally or pathologically induced mitochondrial and cell toxicity.

Animals↗
PubMedDate not supplied

In vitro biological effects of glass fibers.

Two glass fiber samples, which had previously been tested for their ability to induce mesotheliomata in rats, were subjected to size fractionation and the respirable fibers from each were collected. The sizes of the fibers in the total and respirable fractions were measured and all four materials were tested in vitro for their cytotoxic activities against V79-4 cells, A549 cells, and mouse peritoneal macrophages. The respirable fraction from the coarser material had considerably enhanced activity (on a mass basis) compared with its parent (total) material. The respirable fraction of the other fiber was only slightly more active than the corresponding total sample. The fiber size distributions are discussed in relation to the observed biological activity of all four samples, and it is concluded that the cytotoxic activity of fibrous glass is determined by the number of fibers within certain size ranges. It is likely that in the systems used in this present paper, fibers less than 10 micrometer long are inactive. The relationship between these observations and those obtained with fibrous glass in vivo by Stanton et al. (1977) are discussed.

Animals↗
PubMedDate not supplied

Pediatric trauma: preparation and management.

1. Trauma causes more than 50% of the deaths in children. The leading cause of pediatric injury is motor vehicle accidents involving children as passengers, pedestrians, or bicycle riders. 2. Trauma is always unexpected; therefore, the most vital aspect of any trauma system is that the system itself never be caught unprepared. Anticipation and preparation are the best first-line defenses against traumatic injury. 3. Because of a child's smaller size, vital organs are in close proximity to one another; multiple organ injuries are common. 4. The team who responds to a pediatric trauma should include nurses and physicians trained in principles of pediatric resuscitation.

Accidents, Traffic↗