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Biomedical subjects

J Shepherd

Publications and source records attributed to J Shepherd.

At least 289 records · Page 16Linked to original sources

Epstein-Barr virus and jaw tumors in North Nigeria.

Nigerian patients with tumors of the jaw were compared with controls in respect of antibodies to the viral capsid antigens of Epstein-Barr Virus (EBV) and of total immunoglobulin levels. Immunoglobulin levels did not differ between patients and controls but increased two weeks postsurgery. Immunoglobulin A (IgA) antibodies to EBV were detected in a small number of patients, and mean titers of IgG antibodies to EBV were lower in the patient group, indicating a lack of association between EBV and tumor formation. An association was noted between the presence of Hepatitis B surface antigen, and depressed antibody titers to EBV in patients with tumors. Of 78 patients studied, 12% were Hepatitis B surface antigen positive.

Ameloblastoma↗

High-dose cyclophosphamide followed by cisplatinum in the treatment of ovarian cancer.

Twenty patients with previously untreated ovarian cancer received intensive chemotherapy after initial surgery. Treatment comprised two courses of cyclophosphamide at 7 g/m2 with mesna, re-evaluation with second-look laparotomy where appropriate, followed by five courses of cisplatin at 100 mg/m2. Three patients achieved pathologically documented complete remission (PDCR) with high-dose cyclophosphamide, and eight patients achieved partial remission. Fifteen patients went on to receive cisplatin. Nine of these patients had no assessable disease; of six patients who were assessed for response two achieved PDCR and three achieved partial remission. The overall response rate to the sequential regimen was 14/20 (70%). High-dose cyclophosphamide was associated with marked haematological toxicity, which was cumulative and fatal in two patients. The median duration of first remission was 14 months, and the median duration of survival was 20 months. It is concluded that sequential treatment with high-dose cyclophosphamide and cisplatin appears to be no more effective than conventional treatment in advanced ovarian cancer, judging by the PDCR rate and median survival achieved.

Adult↗

Variability and reversibility of the slow and forced vital capacity in chronic airflow obstruction.

The variability of the forced (FVC) and slow vital capacity (SVC) manoeuvres were compared in 33 adult patients with chronic airflow obstruction. The reversibility of the two manoeuvres to nebulized salbutamol were compared in 18 of the patients. Both manoeuvres had equally small variances both before and after bronchodilator. The degree of reversibility of the FVC was however significantly greater (P less than 0.05) than the SVC. Although both measurements are equally variable, the FVC has a greater capacity for reversibility, which may have clinical significance.

Albuterol↗

Continuous estrogen/progestin therapy in menopause.

The incidence of vaginal bleeding, endometrial histology, menopausal symptoms, blood pressure, and serum lipid concentrations were evaluated in 26 women who received either continuous conjugated equine estrogens and medroxyprogesterone acetate (group I, N = 16) or cyclic conjugated equine estrogen + medroxyprogesterone acetate (group II, N = 10) over a 9-month treatment period. At the end of therapy, endometrial biopsy specimens in group I revealed inactive endometrium, whereas one of ten biopsy specimens in group II showed proliferative endometrium. Blood pressure, serum total cholesterol, high-density and low-density lipoprotein cholesterol, and triglyceride levels were not significantly altered from baseline in either group during the 9-month treatment. Vaginal bleeding was virtually eliminated in group I by the end of the study, while 80% of the patients in group II continued to have cyclic menses (p less than 0.001). This pilot study suggests that continuous conjugated equine estrogen plus medroxyprogesterone acetate therapy appears to be a satisfactory method of postmenopausal hormone replacement, effectively reducing menopausal symptoms without any apparent short-term alterations in serum lipids. It has the added benefit of eliminating cyclic menstrual flow.

Biopsy↗

Evidence for a possible cytosol estrogen receptor deficiency in endocervical glands of infertile women with poor cervical mucus.

Endocervical gland estrogen receptor (ER) deficiency has been proposed as a possible cause for the poor cervical mucus (CM) in some infertile women with cervical factor. Cytosol ERs were measured in endocervical tissue obtained by biopsy within 3 days of ovulation (determined by the endogenous luteinizing hormone [LH] surge) in five infertile women with persistent poor preovulatory CM (group 1) and in endocervical tissue obtained in the late follicular phase in eight ovulatory women with excellent CM (group 2). ER concentrations were measured in Fmol/mg protein by the dextran-coated charcoal separation method (New England Nuclear Kit, Boston, MA). CM score evaluation and measurement of serum estradiol (E2) and progesterone (P) levels were performed concomitantly. Serum E2 levels of 123.4 +/- 29.3 pg/ml (mean +/- standard error of the mean [SEM]) in group 1 were comparable to E2 levels of 123.3 +/- 15.0 pg/ml in group 2. Serum P concentrations of 0.9 +/- 0.27 ng/ml in group 1 were comparable to 0.79 +/- 0.29 in group 2. A CM score of 4.6 +/- 0.69 in group 1 was significantly lower than 11.6 +/- 0.53 in group 2 (P less than 0.01). The cytosol ER was negative in four of five women in group 1, whereas in group 2, ER was positive in six, borderline in one, and negative in one subject. This study suggests that cytosol ER may be deficient in some women with cervical factor.

Adult↗

Lipid transport through the plasma: the metabolic basis of hyperlipidaemia.

Plasma lipid abnormalities derive their importance from their association with coronary artery disease. Elevated cholesterol levels accentuate risk, and clinical trials have shown that reductions lead to a decline in coronary events. The major plasma lipids, cholesterol and triglyceride, circulate in association with specific proteins as lipid-protein or lipoprotein complexes. The proteins direct and regulate the metabolism of these complexes by interacting with tissue enzymes and receptors. The metabolic fate of circulating triglyceride is governed by the activity of the enzyme lipoprotein lipase, situated in adipose tissue and skeletal muscle. Cellular demand for cholesterol, on the other hand, is met by activation of a specific receptor which mediates the delivery of sterol-rich lipoproteins to lysosomal degradation in liver and peripheral tissues. In order to prevent excess cholesterol accumulation at the periphery, there is a system of reverse cholesterol transport which involves assimilation and trapping of the sterol in the plasma lipoproteins through the action of the enzyme lecithin:cholesterol acyltransferase. Thereafter, the cholesterol is delivered to the liver, the only organ capable of excreting it in significant amounts. Disturbances in these processes may produce gross changes in the plasma lipid profile, clearly recognizable as hyperlipidaemia. However, it is becoming increasingly clear that a number of inherited traits can subtly perturb the lipoprotein spectrum and increase coronary risk even in subjects whose plasma lipoprotein profile would be considered normal.

Apolipoproteins↗

Pre-race drop-out in marathon runners: reasons for withdrawal and future plans.

This study examines the reasons given for non-participation in the 1984 Aberdeen Milk Marathon by those people who entered for the race but did not run. The major reason was found to be injury during training. The future running plans of the sample were also investigated and it was found that the vast majority aimed to continue marathon running. Around two-thirds of the sample had decided not to run at least two weeks before the day of the race. A third of the respondents indicated that they would have taken part in the race had there been a half marathon option.

Adult↗

Prevention of cardiovascular disease in general practice: a proposed model.

A screening model based in general practice for the detection of subjects at risk of premature cardiovascular disease is described. Opportunistic screening is performed by a trained nurse who also gives initial advice on management. Immediate feedback to patients is possible since a rapid dry chemistry technique is used to measure blood cholesterol concentrations. The collation and analysis of data are achieved using a microcomputer. A central deidentified database is incorporated to allow epidemiological studies and intervention strategy evaluations to be made. Nineteen health centres have evaluated the model, and 40,000 subjects have been screened: 10% had diastolic blood pressures of over 95 mm Hg and 15% had a blood cholesterol concentration over 7 mmol/l (270 mg/100 ml) and 2% over 9 mmol/l (347 mg/100 ml). The initial data suggest that the model is acceptable to both health centre personnel and the general public and that the offer of screening is taken up by all elements of the target population.

Adult↗

Receptor-independent low-density lipoprotein catabolism.

Cultured cells, animal models, and man all possess mechanisms for LDL degradation that do not require the agency of the high-affinity receptor. In healthy individuals their functional significance can be determined using LDL which has been modified by specific chemical reactions designed to inhibit it receptor binding. Although the precise nature of the pathways has not been defined, there is evidence to implicate the monocyte-macrophage system in the process.

Animals↗

Lipoprotein receptors and atherosclerosis.

Mammalian cholesterol metabolism is governed by two key features of the steroid nucleus: it is poorly soluble in plasma and it cannot be degraded in animal tissues. Cells which require the lipid import it through their cytoplasmic membranes in the form of solubilized lipid-protein complexes, and a similar export mechanism is essential in order to maintain cellular homoeostasis. The translocation is mediated by high affinity receptors which, under normal circumstances, operate in close synchrony. Changes in the nature of the lipoprotein ligand or of the cell itself may disturb this balance and lead to the pathological sterol accumulation which characterizes atherosclerotic lesions. All body tissues engage in this traffic in cholesterol but the liver is the single most important organ since it has the capacity both to synthesize large quantities of the lipid and to excrete it from the body via a variety of receptors designed to maintain peripheral sterol levels within safe limits.

Arteriosclerosis↗

Modelling population changes in small English urban areas.

The authors examine processes underlying the growth of small urban areas in England. "There is evidence of 'people-led' growth in environmentally attractive locations (for example, through retirement migration). However, growth of small- and medium-sized towns also reflects employment decentralisation and deconcentration to freestanding or satellite towns, and the extension of commuter hinterlands.... Government policies encouraging growth are also demonstrated to be significant." The processes resulting in population decline in some small towns are identified. "The impact on modelling growth in urban areas of a diversity of causal processes and locational contexts for growth is considered."

Behavior↗