Tn10 transposase acts preferentially on nearby transposon ends in vivo

Transposition of Tn10 requires sites at the termini of the element and one essential transposon-encoded function, "transposase", which acts at those termini. Genetic complementation experiments reveal that this "transposase" function works much more efficiently on transposon ends located near the gene from which they are expressed than on transposon ends located at a distance. This property accounts for the failure of mutant Tn10 elements to be efficiently complemented in trans. The failure of transposase protein to move freely in three dimensions could be explained by one-dimensional diffusion, energy-dependent translocation and/or extreme protein lability. Additional genetic analyses demonstrate that the rate of Tn10 transposition in vivo depends upon the length of the transposon and the amount of transposase protein. Function dependence and length dependence are independent aspects of the transposition process that could correspond to the break/join and replication aspects into which transposition has been separated conceptually.

Metabolic response to starvation. I. Relative effects of pregnancy and sex steroid administration in the rat

Increased sensitivity to a fast with rapid onset of ketosis, hypoalaninemia, and hypoglycemia is characteristic of rat and human gestation. The present study examines the role of sex steroids in the development of these metabolic changes. Subgroups of female rate received 10 microgram of estradiol (E), 10 mg of progesterone (P), or the two in combination (E + P) s.c. daily for 5 days. Control rats (C) received sesame oil alone. Different groups were starved 12, 24 and 48 hr during days 4 and 5 or treatment. Plasma substrate and insulin responses were measured and compared to results of similar studies performed on rats in late gestation. Administration of E or P along had no significant effects on measured parameters as compared to control values. However, the combined E + P regimen resulted in significantly higher ketonemia, greater hypoalaninemia, and relatively higher triglyceride concentrations than in control groups during fasting. Plasma triglyceride, free fatty acid, and ketone concentrations in the pregnant group exceeded values of both the E + P and control animals. However, plasma free fatty acids in the E + P group were significantly lower as compared to control values during starvation. These data suggest that the combined effects of estradiol and progesterone enhance ketogenesis and hypoalaninemia independent of the fetal-placental unit during starvation in pregnancy. Since the ketogenic effect was associated with a relative suppression of plasma free fatty acids, this may be indicative of a direct action of these hormones on hepatic disposition of free fatty acids and/or the biosynthetic pathways for ketone body production.

Metabolic response to starvation. II. Effects of sex steroid administration to pre- and postmenopausal women

Premenopausal women become more ketotic than do men during short term starvation. The possible influence of female sex steroids on ketosis during an 84-hr fast was studied in premenopausal women receiving combined oral contraceptive steroids. The results were compared to age and weight-matched women on no steroid birth control regimen. Although concentrations of several plasma substrates, insulin, and glucagon were measured throughout the fast, no differences between groups were observed with the exception of the 36-hr interval. At this time total plasma ketones and betahydroxybutyrate were significantly higher in women receiving oral contraceptives. In a second study six postmenopausal women were investigated in a similar fashion during a 36-hr fast. The procedure was repeated following a 5 day treatment regimen of oral estradiol and medroxyprogesterone acetate. After sex steroid treatment, total plasma ketones and betahydroxybutyrate concentrations exceeded control values significantly at 36 hr while plasma alanine and free fatty acid levels were significantly lower. The results suggest that oral estrogen-progestin combinations increase the ketogenic response of pre- and postmenopausal women during the early phases of total starvation. This hormonal effect may explain, in part, why women are more sensitive to fasting than are men.

Chronic mucocutaneous candidiasis with candida granuloma treated with 5-fluorocytosine

A 19-year-old male had chronic mucocutaneous candidiasis with typical granuloma on the face, scalp and genital area. He had defects in cell-mediated immunity (cutaneous anergy to common antigens, but normal number of T lymphocytes and normal lymphocyte transformation with phytohemagglutinin), and there were no endocrine deficiencies. He had systemic involvement, including lungs, kidneys, liver and spleen diagnosed by radiologic studies. In the histologic findings of the skin, typical features were seen of candida granuloma lesions, and hyphae and spores of Candida albicans also were identified in the Malpighian layer. Therapy with 5-fluorocytosine resulted in a remarkable improvement.

Effects of parathyroid hormone infusion and primary hyperparathyroidism on serum prolactin in man

Serum PRL, parathyroid hormone (PTH), and Ca levels were measured in 14 patients (8 women and 6 men) with primary hyperparathyroidism. Six normal volunteers (3 men and 3 women) received a 1-h control infusion of 5% glucose containing 2% human serum albumin, a 1-h infusion of the same fluid containing 450 U bovine PTH, and a repeated 1-h infusion of glucose and albumin. Serum PRL was measured during these infusion periods and showed a peak within 30 min of the start of bovine PTH infusion; PRL levels declined therafter in spite of continued PTH infusion. Serum PRL levels returned to normal within 1 h of discontinuance of bovine PTH infusion. The serum PRL levels in patients with primary hyperparathyroidism were within the normal range, and there was no correlation between serum PTH and PRL levels. These results suggest that the PRL response to PTH infusion is a pharmacological rather than a physiological or pathophysiological effect of PTH.

Correlation of hyperprolactinemia with altered plasma insulin and glucagon: similarity to effects of late human pregnancy

Plasma glucose and insulin concentrations were measured during oral glucose and iv tolbutamide tolerance tests in nine women with hyperprolactinemia and the amenorrheagalactorrhea syndrome (AGS). Glucose tolerance curves, basal insulin levels, and postchallenge plasma insulin responses were significantly higher in AGS women compared to those in an age- and weight-matched control group. Fasting plasma glucagon concentrations were unaltered in AGS, but suppression of the hormone after oral glucose was greater and more prolonged relative to the control response. Oral glucose tolerance tests were performed on nine normal women during late pregnancy who had physiological hyperprolactinemia comparable to that in the AGS group. Glucose tolerance curves, exaggerated plasma insulin responses, and glucagon suppression resembled those observed in the AGS women. These results suggest that elevated plasma PRL concentrations may contribute to the development of hyperinsulinemia and accentuated glucagon suppression in response to glucose that is characteristic of late human pregnancy.

Studies of murine complement. Correlation of hypocomplementemia with other disease parameters in individual NZB/W mice and demonstration of anti-complementary material

We have utilized a new assay for murine complement components to explore the relationship of complement titers to other parameters of disease activity in individual NZB/W female mice. Titers had fallen significantly by 6 months of age, concomitantly with the appearance of antiDNA in serum and of C3 and immunoglobulin in renal glomeruli. The period of hypocomplementemia antedating proteinuria was extremely variable. Heat stable anti-complementary material was found in serum from older NZB/W mice.

Clinical significance of synovial fluid total hemolytic complement activity

Total hemolytic complement (CH50) was measured in 174 synovial fluids (SF) to determine its diagnostic and and prognostic value. SF CH50 was reduced relative to serum CH50 in 61% of patients with rheumatoid arthritis and 60% of patients with crystal-induced arthritis. There was no correlation of SF CH50 levels with disease duration, SF leukocyte count, presence of IgM rheumatoid factor, or radiologic evidence of erosions.

Cryptococcosis with cutaneous manifestations treated with 5-fluorocytosine

A 3-year-old girl in poor general condition was admitted with a diagnosis of cryptococcosis and treated with 5-fluorocytosine. This case is characterized by its occurrence at a young age with no underlying disease, with involvement of the central nervous system, lung, skin, liver, spleen and lymph nodes, with typical cutaneous papules and nodules with ulceration and crushing, gelatinous appearance on biopsy of the skin, severe peripheral eosinophilia, and a remarkable response to 5-fluorocytosine therapy monitored by follow-up skin biopsies.

Changes in lipoprotein composition during the menstrual cycle

Composition of major plasma lipoproteins was studied in 14 normal women during different phases of the menstrual cycle for three consecutive months. The results were compared to measurements in ten normal age-matched men for a comparable period, to delineate possible sex differences in lipoprotein metabolism in young adults. Blood samples were obtained every 3--5 days after a 14-hr overnight fast and processed for determinations of total plasma cholesterol, LDL- and HDL-cholesterol, and apoproteins B and A-1. In premenopausal women, a significant, 10%--25% cyclical suppression of total plasma cholesterol, LDL-Chol, and LDL-apoB occurred during the luteal phase, which was significantly lower than unchanging concentrations found in men at any time interval. HDL-Chol remained in a significantly higher fixed concentration range in the female subjects as compared to the men. These sex differences in lipoprotein metabolism may have relevance to the reduced susceptibility of premenopausal women to atherosclerosis.

Radiation-related thyroid carcinoma

Of 1,825 subjects with a history of head or neck irradiation, 358 (19.6%) were found to have thyroid abnormalities. One hundred sixty-five (9%) had either single or multiple nodules 153 (8.4%) had diffuse thyromegaly, and 40 (2.2%) had had thyroid surgery. Surgery was performed on 113 subjects with nodules; carcinoma was found in 34 (30.1%). Clinical examination of the neck was the most valuable method of detecting abnormalities. Detection of nodules was not significantly enhanced by routine use of thyroid imaging studies. Measurements of levels of serum thyroid-stimulating hormone, thyroxine, triidothyronine resin uptake, and thyroid antibodies were not useful in screening for nodules or carcinoma.

The influence of hormonal changes of pregnancy on maternal metabolism

Mammalian pregnancy is characterized by progressive hyperinsulinaemia, raised plasma lipids and increased vulnerability to ketosis after food deprivation. The present investigations were performed to assess the role of two placental steroids, oestradiol and progesterone, in the development of these changes, since plasma titres of these hormones progressively increase during human gestation. In both human subjects and adult female rats it was demonstrated that these two steroids, separately or in combination, augment plasma insulin concentration in vivo, cause hypertrophy of pancreatic islets and promote exaggerated secretion of insulin, but not glucagon, by pancreatic islets in vitro. Hypertriglyceridaemia induced by oestrogen alone or combined with progesterone was associated with increased splanchnic production of triglyceride as well as altered tissue lipoprotein lipase (EC 3.1.1.34) and circulating apoproteins that influence activity of this enzyme. The combined regimen also increased hepatic glycogen storage and suppressed gluconeogenesis in vivo in the rat while accelerating the onset of ketosis during starvation in human subjects and in the animal model. Oestradiol and progesterone appear to effect metabolic changes in nonpregnant animals and human subjects that simulate maternal adaptations to advancing gestation, including altered endocrine pancreatic function, triglyceride metabolism and metabolic fuel storage and mobilization.