PubMed Health⌕ Search

Biomedical subjects

S Sharpe

Publications and source records attributed to S Sharpe.

31 records · Page 2Linked to original sources

Intrarectal challenge of macaques vaccinated with formalin-inactivated simian immunodeficiency virus.

Macaques can be protected from intravenous infection with simian immunodeficiency virus (SIV) by vaccination with chemically inactivated virus. However, protection against infection via a mucosal surface has not been demonstrated. We vaccinated four rhesus macaques with formalin-inactivated SIV given intramuscularly. These monkeys, which had remained virus free for 10 months after intravenous challenge with SIV, were given a further dose of vaccine and together with four unvaccinated controls were challenged intrarectally with SIV. Subsequently, virus was isolated from all control animals on five successive occasions, but the vaccinated animals remained free of virus. Proviral DNA could not be detected in peripheral blood mononuclear cells from the vaccinated animals. Preliminary data indicate that vaccinated animals make a local antibody response.

AIDS Vaccines↗

Risk, power and the possibility of pleasure: young women and safer sex.

This paper draws on the work of the Women Risk and AIDS Project (WRAP) which was undertaken by the authors working collectively. It reports on data from a sociological study of the sexual beliefs and practices of two samples each of 75 young women between 16 and 21 in the cities of London and Manchester in the UK. The period of data collection was 1988-1990. The paper sets out the methods used by the WRAP team and locates this research process within wider debates about feminist theory and methodology. There then follows a discussion of the main research findings--relating to the respondents sexual practice--which are then illustrated in some detail in relation to the themes of 'risk and trust' and 'power and empowerment'. Based on these findings conclusions are drawn about the need for a gendered dimension in the development of policy and practice for HIV and AIDS prevention.

Adolescent↗

p24 antibody production in p24 antibody-negative HIV-infected subjects.

To determine if HIV-infected patients with no detectable serum antibodies to p24 are producing antibodies to p24 (anti-p24), blood was obtained from 49 HIV-infected patients at various stages of infection. Serum p24 antigen levels were measured and peripheral blood mononuclear cells were cultured for 1 week without mitogenic stimulation. The presence of anti-p24 in culture supernatants and sera was determined by radioimmunoprecipitation assays. Cells from 89% of the patients who had anti-p24 in their sera spontaneously synthesized anti-p24 in vitro. Similarly, cells from 83% of the HIV-infected patients who had no detectable anti-p24 in their sera spontaneously produced anti-p24 in vitro. Thus the absence of anti-p24 in serum did not reflect suppression in the ability of patients' cells to synthesize and secrete antibodies to p24. However, cells from patients whose sera contained anti-p24 spontaneously synthesized more anti-p24 than did cells from patients whose sera lacked anti-p24, suggesting that these two groups of patients may represent individuals with inherently high or low responses to p24 epitopes, respectively.

AIDS-Related Complex↗

Determinants of total body and regional bone mineral density in normal postmenopausal women--a key role for fat mass.

In order to determine which clinical, anthropometric, dietary, and biochemical variables are independent predictors of total and regional bone mineral density (BMD) in normal postmenopausal women, a cross-sectional study of 140 normal postmenopausal women has been carried out. Subjects were white, aged 45-71 yr (mean 58 yr), and had no history of disorders or medication use likely to influence bone or calcium metabolism. Multiple regression analysis was used to derive models for total and regional BMD in terms of the other variables measured. The analysis indicated that total body BMD was positively related to fat mass (P less than 0.0001), serum estrone (P = 0.0095) and age at menopause (P = 0.0165), and negatively related to age (P less than 0.0001), 24-h urine calcium (P = 0.0002), sex hormone-binding globulin (P = 0.0003), and serum alkaline phosphatase activity (P = 0.0029) (R2 = 0.61). Similar relationships were found in the subregions of the total body scans and in the lumbar spine and proximal femur, with insulin-like growth factor-1, parity, and age at menarche also being related to BMD at at least two of these sites. Lean body mass was not an independent correlate of BMD at any site once fat mass was taken into account. Muscle strength, physical activity, alcohol intake, and dietary intakes of calcium, sodium and protein did not emerge as significant predictors of BMD in this homogeneous group of postmenopausal women. We conclude that total body fat is the most significant predictor of BMD throughout the skeleton and this relationship is not explicable in terms of either estrone production in fat tissue or the dependence of skeletal load-bearing on fat mass. The mechanism underlying this relationship is an important question to be addressed in bone biology.

Aged↗

Recognizing panic in cardiac patients.

Patients presenting with apparent myocardial infarctions may in fact be suffering from panic attacks; many symptoms of the latter mimic those of the former. Cardiovascular nurses who know what to listen for in patients' descriptions can recognize indications that panic may be occurring. This article describes panic attacks, panic disorder, and the long-term consequences that often accrue when this highly treatable problem is not recognized. Particularly when no evidence of myocardial damage is found, a cardiovascular nurse's recognition of panic can lead to a referral for appropriate psychological treatment, preventing years of needless suffering and unnecessary health care costs.

Female↗

Generation of human monoclonal antibodies to human immunodeficiency virus.

Based on the finding that cells producing antibodies to human immunodeficiency virus (HIV) circulate in the peripheral blood of HIV-infected individuals, attempts were made to immortalize such B cells with Epstein-Barr virus. Mononuclear cells from 58 HIV-seropositive subjects at various stages of HIV infection were transformed, and anti-HIV cell lines were derived from 4 subjects, all of whom were in early stages of infection. Seven of these cell lines have been stable with respect to antibody production for up to 15 months. Three lines are producing IgG antibody to the 41-kDa HIV transmembrane glycoprotein gp41 and 4 produce IgG antibodies to the 24-kDa HIV core protein p24, its precursors and a breakdown product. The antibodies are reactive by ELISA, by radioimmunoprecipitation, and by Western blot, demonstrating the feasibility of producing multiple stable cell lines synthesizing human monoclonal antibodies to HIV by immortalization of peripheral blood cells with Epstein-Barr virus.

Acquired Immunodeficiency Syndrome↗

Cerebral ischemia and reperfusion: prevention of brain mitochondrial injury by lidoflazine.

Mitochondrial degradation is implicated in the irreversible cell damage that can occur during cerebral ischemia and reperfusion. In this study, the effects of 10 min of ventricular fibrillation and 100 min of spontaneous circulation on brain mitochondrial function was studied in dogs in the absence and presence of pretreatment with the Ca2+ antagonist lidoflazine. Twenty-three beagles were separated into four experimental groups: (i) nonischemic controls (ii) those undergoing 10-min ventricular fibrillation, (iii) those undergoing 10-min ventricular fibrillation pretreated with 1 mg/kg lidoflazine i.v., and (iv) those undergoing 10-min ventricular fibrillation followed by spontaneous circulation for 100 min. Brain mitochondria were isolated and tested for their ability to respire and accumulate calcium in a physiological test medium. There was a 35% decrease in the rate of phosphorylating respiration (ATP production) following 10 min of complete cerebral ischemia. Those animals pretreated with lidoflazine showed significantly less decline in phosphorylating respiration (16%) when compared with nontreated dogs. Resting and uncoupled respiration also declined following 10 min of fibrillatory arrest. One hundred minutes of spontaneous circulation following 10 min of ventricular fibrillation and 3 min of open-chest cardiac massage provided complete recovery of normal mitochondrial respiration. Energy-dependent Ca2+ accumulation by isolated brain mitochondria was unimpaired by 10 min of complete cerebral ischemia. However, by 100 min after resuscitation, there was a small, but significant rise in the capacity for mitochondrial Ca2+ sequestration when compared to either control or fibrillated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

Serum IgD elevation is an early marker of B cell activation during infection with the human immunodeficiency viruses.

Serum IgD levels in individuals infected with the human immunodeficiency viruses (HIV) were studied as a means of monitoring the character and timing of B cell activation in individuals with this infection. Significantly increased levels of IgD were characteristic of homosexual men who were HIV seropositive but asymptomatic or mildly symptomatic. The hyper IgD globulinaemia became progressively more pronounced in patients with increasingly severe infection and reached its most marked level in patients with AIDS-related complex (ARC). In ARC patients, IgD levels were increased 8.8-fold above normal which was disproportionately greater than the 2.4-fold increase in IgG, the 1.8-fold increase in IgA and the 1.6-fold increase in IgM. IgD levels declined in AIDS patients (although remained elevated compared to controls). The data suggest that an unusual type of B cell activation is responsible for the unique pattern of hypergammaglobulinaemia seen in this disease and that the B cell activation occurs early in the pathogenesis of HIV infection, often before development of symptoms, and continues throughout the course of infection.

AIDS-Related Complex↗