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Biomedical subjects

K Stewart

Publications and source records attributed to K Stewart.

At least 91 records · Page 5Linked to original sources

Diagnostic and treatment results from a southeastern academic center-based premenstrual syndrome clinic: the first year.

OBJECTIVES: We attempted to ascertain the following: (1) the yield of a structured workup in a premenstrual syndrome clinic coordinated by a university-based gynecology department in the southeast, (2) referral patterns and care provided before consultation, and (3) therapeutic outcomes. STUDY DESIGN: The first 100 women seen prospectively entered a uniform diagnostic and treatment protocol. Data analysis was performed with analysis of variance and confidence interval for a population proportion. RESULTS: Thirty-eight women (95% confidence interval 28% to 48%) had premenstrual syndrome, 24 had premenstrual magnification syndrome (95% confidence interval 16% to 32%), 13 had an affective or other psychiatric disorder (95% confidence interval 6% to 20%). Only 44% of women previously given a diagnosis of premenstrual syndrome were found to have premenstrual syndrome. Overall, 84% of women with premenstrual syndrome and premenstrual magnification syndrome responded to treatment. CONCLUSIONS: Too many women are still given the diagnosis of premenstrual syndrome without appropriate prospective documentation. Premenstrual magnification represents an important diagnostic category. Therapeutic responses to present treatments are encouraging.

Adolescent↗

The Albrecht Nursing Model for Home Healthcare. Predictors of satisfaction with a self-care intervention program.

Satisfaction with a self-care intervention program was evaluated through this quantitative study of arthritis clients at home. The results indicate that the clients were highly satisfied with the intervention. In this era of consumer satisfaction with their care, nurse administrator's knowledge of which interventions are satisfying is important for staff development and case management in the community.

Adult↗

Complement-mediated binding of naturally glycosylated and glycosylation-modified human immunodeficiency virus type 1 to human CR2 (CD21).

Particulate glycoproteins lacking sialic acid, such as desialylated enveloped viruses, readily activate complement through the alternative pathway. Human immunodeficiency virus type 1 (HIV-1) contains two heavily glycosylated and partially sialylated envelope glycoproteins: a surface gp120 and a transmembrane gp41. The abilities of naturally glycosylated HIV-1 and glycosylation-modified HIV-1 to interact with the complement system were examined with a biological assay which measured the binding of whole virus particles to cells expressing CR2 (CD21), the complement receptor found naturally in abundance on follicular dendritic cells and immature B cells. HIV-1 IIIB was synthesized in the presence or absence of the mannosidase II inhibitor, swainsonine, to give rise to high-mannose-type, nonsialylated, nonfucosylated carbohydrate moieties. The virus also was treated with neuraminidase or endo-beta-galactosidase to remove terminal sialic acids. An enzyme immunoassay specific for HIV-1 p24 core protein was used to quantitate the amount of virus bound to cell surfaces. Virus particles incubated with 1:3-diluted, fresh HIV-1-negative human serum as a source of complement readily bound to MT-2 (CD4+ CR2+) and Raji-3 (CD4- CR2+) cells but not to CEM (CD4+ CR2-) cells, suggesting that the virus bound to CR2 independently of CD4. Compared with heat-inactivated or C3-deficient sera, fresh complement increased binding by as much as 62 times for naturally glycosylated virus, and 5 times more than this for glycosylation-modified virus. Similar observations were made with freshly isolated, non-mitogen-stimulated peripheral blood mononuclear cells. Additional evidence that HIV-1 bound to CR2 independently of CD4 was provided by the fact that binding was blocked by monoclonal antibody OKB7 (anti-CR2) but not by OKT4a (anti-CD4). Also, the virus bound to transfected K562 cells (CD4-) which expressed recombinant human CR2 but did not bind to untransfected K562 cells. Results obtained with complement component-deficient sera indicated that binding required the alternative complement pathway. Raji-3 and transfected K562 cells could not be infected with HIV-1 in the presence of complement, suggesting that utilization of CR2 as a receptor in the absence of CD4 does not allow virus entry. The demonstration of CR2 as a receptor for HIV-1 in the presence of complement, together with the ability to enhance binding by desialylation, provides new insights into mechanisms of HIV-1-induced immunity and immunopathogenesis.

Acquired Immunodeficiency Syndrome↗

Purinergic receptor activation of Cl- secretion in T84 cells.

The regulation by ATP of Cl- secretion in T84 cells grown on filters was investigated by measuring short-circuit current (Isc = net Cl- secretion). ATP (greater than or equal to 10 microM) added to the basolateral side markedly stimulated Isc both in the presence and absence of forskolin-activated Isc. Fluorescence microscopy of cells loaded with the Ca2+ indicator fura-2 showed that ATP stimulated a transient increase in intracellular free Ca2+ concentration [Ca2+]i. The augmentation of forskolin-stimulated Isc by ATP was at least partly caused by mobilization of Ca2+ from an internal store because prior depletion of the store using ionomycin prevented the response. The activity sequence for stimulation of Isc in the presence of forskolin was adenosine 5'-O-(3-thiotriphosphate) = 5'-adenylylimidodiphosphate (AMP-PNP) greater than ATP greater than ADP greater than AMP, suggesting the presence of a P2 purinergic receptor. Neither beta, gamma-methyleneadenosine 5'-triphosphate nor alpha, beta-methyleneadenosine 5'-triphosphate increased the Isc. Stimulation of Isc by ATP in the absence of forskolin was at least partly due to the breakdown of ATP to AMP and adenosine, which act at P1 receptors to stimulate Isc, since 1) inhibition of the ecto-phosphohydrolase 5'-nucleotidase by alpha, beta-methylene-ADP partially inhibited stimulation of Isc by ATP, 2) the adenosine receptor antagonists caffeine and 8-phenyltheophylline markedly inhibited the ATP-stimulated Isc, and 3) AMP-PNP, a weakly hydrolyzable analogue of ATP, caused a much smaller increase in Isc compared with ATP. Adenosine had no effect on [Ca2+]i.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

Studies in a kindred with parathyroid carcinoma.

We report a family with primary hyperparathyroidism in four patients in two generations with apparent autosomal dominant transmission. A fifth member was probably affected. Two cases had definite parathyroid carcinoma (PC), and two had parathyroid adenoma with atypical features that could represent an early stage of cancer. In each of our patients, one parathyroid gland was abnormal. Five other parathyroid glands (in two patients) were normal in histology and size. There was no evidence of neoplasia in other tissues. Constitutional karyotypes were normal in all four patients. We identified three chromosomal abnormalities (a reciprocal translocation between chromosomes 3 and 4, trisomy 7, and a pericentric inversion in chromosome 9) in cultured PC tissue from one patient. These chromosomal changes are of unclear significance. Analyses on tumor DNA from one case of PC and one of atypical adenoma showed no evidence of ras gene mutations, PTH gene rearrangement, or allelic loss from chromosome 11q13 (locus of the gene for multiple endocrine neoplasia type 1). This family shows susceptibility to cancer without antecedent hyperplasia in all parathyroids. It could help identify a novel tumor susceptibility gene.

Adenoma↗

Oral dapsone versus nebulized pentamidine for Pneumocystis carinii pneumonia prophylaxis: an open randomized prospective trial to assess efficacy and haematological toxicity.

OBJECTIVE: To compare the haematological toxicity and efficacy of oral dapsone and nebulized pentamidine as Pneumocystis carinii pneumonia (PCP) prophylaxis in HIV-infected patients receiving zidovudine. DESIGN: Randomized, prospective. SETTING: Infectious diseases hospital with participants drawn from both inpatient and outpatient departments. PATIENTS: Those eligible were starting treatment with zidovudine, needed PCP prophylaxis (CD4+ count < 200 x 10(6)/l or < 20% total lymphocyte count or previous episode of PCP), and had a normal glucose-6-phosphate dehydrogenase screen. Of the 98 patients enrolled, 96 returned for follow-up. INTERVENTIONS: Fifty patients received dapsone (100mg orally twice weekly) and 46 pentamidine (400 mg nebulized monthly). Follow-up was for a median of 18 months. MAIN OUTCOME MEASURES: The development of PCP, transfusion requirements, monthly complete blood cell counts, serious adverse reactions and death were recorded. RESULTS: Nine (18%) dapsone and eight (17%) pentamidine recipients developed PCP. There was no significant difference in number of patients transfused (12 dapsone and nine pentamidine recipients) or transfusion-free survival. At exit from the study, mean haemoglobin (11.7 versus 12.4 g/dl), white blood cell (3.9 versus 3.7 x 10(9)/l) and platelet (195 versus 184 x 10(9)/l) counts did not differ for the dapsone and pentamidine arms, respectively. There was no significant difference in the occurrence of serious adverse reactions (six in the dapsone and eight in the pentamidine arm). CONCLUSIONS: Dapsone can be recommended in preference to pentamidine as PCP prophylaxis on the basis of equivalent efficacy, absence of excessive haematological toxicity, low cost and ease of administration.

AIDS-Related Opportunistic Infections↗

Lack of therapeutic efficacy of vitamin A for non-cholera, watery diarrhoea in Bangladeshi children.

Vitamin A deficiency has been postulated to increase childhood mortality, possibly through increasing the severity and case-fatality of infectious diseases like diarrhoea. A clinical trial was conducted to measure the effect of vitamin A therapy on the severity and duration of acute episodes of non-cholera, watery diarrhoea; 83 children with less than 48 h of illness were randomized to receive vitamin A (200,000 IU of retinyl palmitate) orally or placebo during hospitalization at the International Centre for Diarrhoeal Disease Research in Bangladesh. The patients were similar initially with regard to age, nutritional status and severity of diarrhoea prior to admission. No adverse effects of vitamin A were detected. During hospitalization there were no differences between groups in duration of illness or stool output. Thus, vitamin A can be given safely during diarrhoeal illness to augment hepatic reserves and possibly provide a beneficial effect in regard to subsequent episodes of diarrhoea and other infections, but this supplementation should not be expected to have a therapeutic effect on a current episode.

Bangladesh↗

Effect on mortality of community-based maternity-care programme in rural Bangladesh.

Various community-based interventions have been proposed to improve maternity care, but hardly any studies have reported the effect of these measures on maternal mortality. In this study, the efficacy of a maternity-care programme to reduce maternal mortality has been evaluated in the context of a primary health-care project in rural Bangladesh. Trained midwives were posted in villages, and asked to attend as many home-deliveries as possible, detect and manage obstetric complications at onset, and accompany patients requiring referral for higher-level care to the project central maternity clinic. The effect of the programme was evaluated by comparison of direct obstetric maternal mortality ratios between the programme area and a neighbouring control area without midwives. Random assignment of the intervention was not possible but potentially confounding characteristics, including coverage and use of other health and family planning services, were similar in both areas. Maternal mortality ratios due to obstetric complications were similar in both areas during the 3 years preceding the start of the programme. By contrast, during the following 3 years, the ratio was significantly lower in the programme than in the control area (1.4 vs 3.8 per 1000 live births, p = 0.02). The findings suggest that maternal survival can be improved by the posting of midwives at village level, if they are given proper training, means, supervision, and back-up. The inputs for such a programme to succeed and the constraints of its replication on a large scale should not be underestimated.

Adolescent↗

The pharmacokinetics of cefuroxime axetil in the sick elderly patient.

The pharmacokinetics of cefuroxime axetil (RS3 formulation) were studied in 20 elderly patients following admission for lower respiratory or urinary tract infection. The mean age was 83.9 years. A 12-hourly dose of 250 mg was given for five days. The mean time to attain maximum serum concentration was 3.2 h with a mean peak concentration of 8.5 mg/l. The mean serum elimination half-life was 3.5 h and the AUC0-infinity 60.4 mg/h.l. There was no accumulation of the drug in the patients studied after five days treatment. The data suggest that the standard dosage regimen is adequate in the sick elderly patient.

Administration, Oral↗