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Biomedical subjects

L Lipworth

Publications and source records attributed to L Lipworth.

At least 73 records · Page 4Linked to original sources
PubMed1980

Suppression of thyroid radioiodine uptake by various doses of stable iodide.

We studied the effect of various doses of sodium iodide on thyroid radioiodine uptake in euthyroid volunteers by giving single doses of 10, 30, 50, and 100 mg and then daily doses of 10, 15, 30, 50, or 100 mg for 12 days thereafter. All single doses above 10 mg suppressed 24-hour thyroid uptake of 123I to 0.7 to 1.5 per cent. Continued daily administration of 15 mg of iodide or more resulted in values consistently below 2 per cent. A small but statistically significant fall in serum thyroxine (T4) and triiodothyronine (T3) and a rise in serum thyrotropin (TSH) concentrations were observed after eight and 12 days of iodide treatment. These data suggest that the thyroid uptake of radioactive iodine can be markedly suppressed by single-dose administration of 30 mg of stable iodide and that suppression can be maintained with daily doses of at least 15 mg. This study provides guidelines for stable iodide prophylaxis in the event of exposure to radioactive iodine.

Adult↗
PubMed1979

Characterization and experimental use of a monospecific antiserum to factor IX.

Purified human factor IX was used to develop xenogeneic neutralizing and precipitating antibodies. The final antiserum (R2) neutralized only factor IX and was equivalent to 220 Bethesda-inhibitory units. It showed two precipitating lines, one of which disappeared after absorption with human albumin. On immunodiffusion and Laurell immunoelectrophoresis, the albumin-absorbed R2 antiserum showed one precipitin line of identity, or one rocket respectively, with normal plasma, a Red Cross factor IX preparation (rich in factors IX, II and X), the original antigen, and Hemophilia-B antigen-positive plasmas. No line or rocket developed with normal plasma absorbed with aluminum hydroxide or with antigen-negative contained only factor IX neutralizing and precipitating antibodies. Experiments with various factor IX concentrates revealed that the majority contained excess factor IX antigen compared to their coagulant activity. In addition, crossed antigen-antibody electrophoresis uncovered differences in the migration of the factor IX of Konyne preparations, when done in the presence of EDTA or calcium. This monospecific antiserum to human factor IX was subsequently used to investigate a large population of hemophilia B patients and carriers.

Animals↗
PubMed1979

Laboratory prediction of the carrier state in hemophilia B: role of replication of assays.

The authors studied the effect of averaging replicated assays of Factor IX coagulation activity and Factor IX antigen on each plasma specimen in improving the ability to detect carriers of hemophilia B. The improvement resulting from this procedure is particularly marked in tests depending on the linear regression of one characteristic on another to diagnose the carrier state. The effects of averaging assays on the ratio of Factor IX coagulation activity to Factor IX antigen were also explored. The benefits of averaging replications were not greatly increased by use of more than four replications.

Blood Coagulation Tests↗
PubMed1978

Effect of starvation on hypothalamic-pituitary-thyroid function in the rat.

Total starvation in the rat for 2 days did not alter the hypothalamic content of thyrotropin-releasing hormone (TRH), but did decrease both pituitary TSH content and serum TSH concentration. Five days starvation resulted in a significant decrease in serum TSH and a slightly enhanced serum TSH response to exogenous TRH, suggesting that the pituitary retains its sensitivity to TRH. Fasting for 5 days resulted in a decreased 1 and 4th, but an increased 24th thyroid 131I uptake. Other starvation-induced abnormalities of intrathyroid 131I metabolism were a consistent increase in the percent of organified 131I present as MIT and DIT and a decreased percent 131I labeled T4 AND T3. These alterations in the intrathyroid metabolism of 131I in the starved rat probably reflect both a decrease in serum TSH concentration and a decrease in urinary and fecal loss of administered 131I. The serum total and free T4 and total and free T3 concentrations were decreased following 2 and 5 days of starvation.

Animals↗
PubMedDate not supplied

Olive oil and human cancer: an assessment of the evidence.

BACKGROUND: We have attempted to summarize the evidence concerning the association of olive oil intake with cancer risk in humans. METHODS: We reviewed all the studies that met the following criteria: (1) they have directly examined olive oil in the context of an extensive food frequency questionnaire or have evaluated the role of monounsaturated fat in populations of Mediterranean countries where a large fraction of monounsaturated fat originates from olive oil and (2) they have analyzed the data with explicit or implicit control for energy intake to accommodate the likely confounding influence of caloric consumption and to account to a certain extent for differential completeness of reporting between cases and controls. Ecologic studies were also considered and relevant experimental data were invoked. RESULTS: With respect to breast cancer, there is converging evidence for a protective effect, although the data are not definitive. For other cancer types, the overall epidemiologic evidence, although promising, is quantitatively limited and qualitatively suboptimal. CONCLUSIONS: The issue is of major public health importance and deserves additional study.

Animals↗
PubMedDate not supplied

Energy intake and monounsaturated fat in relation to bone mineral density among women and men in Greece.

BACKGROUND: Several variables have been established as risk factors for osteoporosis: it is more common among women and the gender difference increases with age and with years since menopause. Estrogens, androgens, physical activity, and body mass index have been previously shown to be positively associated with bone mineral density and inversely with risk for fractures. METHODS: To assess the effect on bone mineral content of energy-generating nutrients, healthy men (n = 36) and women (n = 118) ages 25-69 years were interviewed among visitors and staff of the University of Athens Department of Medical Physics. Bone mineral density (BMD) was measured by single photon absorptiometry. RESULTS: Demographic and lifestyle variables were not significantly related to BMD in this study, although the patterns were consistent with those previously reported by other investigators. Total energy intake, which also reflects energy expenditure through physical activity, was positively associated with BMD among both men (P = 0.003) and women (P = 0.04). After adjustment for nonnutritional variables and energy intake, monounsaturated fat, which in the Greek population is mostly derived from olive oil, was associated with BMD. The association was positive among both men (P = 0.01) and women (P = 0.03). There was evidence for an inverse association between carbohydrate intake and BMD, but the association was significant only with respect to mono- and disaccharides. CONCLUSIONS: In this population, consumption of monounsaturated fat and physical activity were predictive of bone mineral density, but larger studies are needed.

Adult↗
PubMedDate not supplied

A case-control study of endometrial cancer in relation to reproductive, somatometric, and life-style variables.

A hospital-based case-control study of cancer of the endometrium was conducted in Athens, Greece, from 1992 to 1994. The cases were 145 women residents of Greater Athens with histologically confirmed incident cancer of the endometrium, operated in the two cancer hospitals of the Greater Athens area or the major University Department of Obstetrics and Gynecology. Controls were 298 women residents of Greater Athens hospitalized for bone fractures or other orthopedic conditions in the accident hospital of Greater Athens. The data were analyzed by modeling through multiple logistic regression. The risk of endometrial cancer decreased with the number of livebirths (p for trend < 0.01), with early age at menopause (p = 0.03), and with later age at menarche (p = 0.11), whereas miscarriages and induced abortions were clearly unrelated. There were nonsignificant relations of disease risk with smoking (inverse), alcohol (inverse), and menopausal estrogens (positive), whereas oral contraceptive use was too uncommon to allow meaningful study. The lower risk of the disease associated with current occupations requiring manual activity (p = 0.03) and the lower, although not significantly so (p = 0.36), energy intake of cases in comparison to controls suggest that physical inactivity could be an important risk factor for endometrial cancer. Women with endometrial cancer were significantly taller than control women (p = 0.02). The latter results indicate that excess energy intake in early life, leading to higher attained stature, and excessive energy intake in later life, on account of physical inactivity and leading to higher body weight, converge in increasing the risk for endometrial cancer.

Adult↗