921 resultados para prolactin secretion
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Purpose The present study aimed to review the effect of dehydration during Ramadan fasting on the health and ocular parameters leading to changes in eye function. Methods Articles included in the study were taken from PubMed, Ovid, Web of Science and Google Scholar up to 2014. Related articles were also obtained from scientific journals on fasting and vision system. Results Dehydration and nutrition changes in Ramadan cause an increase in tear osmolarity, ocular aberration, anterior chamber depth, IOL measurement, central corneal thickness, retinal and choroidal thicknesses, and also a decrease in IOP, tear secretion, and vitreous thickness. Conclusion Much research related to the effect of dehydration on ocular parameters during Ramadan fasting exists. The findings reveal association with significant changes on ocular parameters. Thus, it seems requisite to have a comprehensive study on "fasting and ocular parameters”, which will be helpful in making decisions and giving plan to the patients.
After 10 years of clinical trials with liraglutide, do we know whether it is beneficial in diabetes?
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Type 2 diabetes remains an escalating world-wide problem, despite a range of treatments. The revelation that insulin secretion is under the control of a gut hormone, glucagon-like peptide 1 (GLP-1), led to a new paradigm in the management of type 2 diabetes. Liraglutide is a long acting GLP-1 receptor agonist used in the treatment of type 2 diabetes. The review considers the clinical trials with liraglutide. There are many comparator trials between liraglutide and other medicines for the treatment of type 2 diabetes, and these trials have shown that liraglutide lowers HbA1c and body weight, and is well tolerated. A large cardiovascular safety trial with liraglutide is presently being undertaken. After 10 years of clinical trials with liraglutide, we do not know whether liraglutide has cardiovascular safety in subjects with type 2 diabetes and high cardiovascular risk. Although this is not a requirement for registration by the Food and Drug Administration (FDA), in my opinion, they should reconsider this. We also do not presently know whether liraglutide has any beneficial effects on clinical cardiovascular outcomes.
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Cushing's syndrome, which is characterized by excessive circulating glucocorticoid concentrations, maybe due to ACTH-dependent or -independent causes that include anterior pituitary and adrenal cortical tumors, respectively. ACTH secretion is stimulated by CRH, and we report a mouse model for Cushing's syndrome due to an N-ethyl-N-nitrosourea (ENU) induced Crh mutation at -120 bp of the promoter region, which significantly increased luciferase reporter activity and was thus a gain-of-function mutation. Crh -120/+ mice, when compared with wild-type littermates, had obesity, muscle wasting, thin skin, hair loss, and elevated plasma and urinary concentrations of corticosterone. In addition, Crh-120/+ mice had hyperglycemia, hyperfructosaminemia, hyperinsulinemia, hypercholesterolemia, hypertriglyceridemia, and hyperleptinemia but normal adiponectin. Crh -120/+ mice also had low bone mineral density, hypercalcemia, hypercalciuria, and decreased concentrations of plasma PTH and osteocalcin. Bone histomorphometry revealed Crh-120/+ mice to have significant reductions in mineralizing surface area, mineral apposition, bone formation rates, osteoblast number, and the percentage of corticoendosteal bone covered by osteoblasts, which was accompanied by an increase in adipocytes in the bone marrow. Thus, a mouse model for Cushing's syndrome has been established, and this will help in further elucidating the pathophysiological effects of glucocorticoid excess and in evaluating treatments for corticosteroid-induced osteoporosis.
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The proinflammatory cytokine IL-17 has an important role in pathogenesis of several inflammatory diseases. In immune-mediated joint diseases, IL-17 can induce secretion of other proinflammatory cytokines such as IL-1, IL-6 and TNF, as well as matrix metalloproteinase enzymes, leading to inflammation, cartilage breakdown, osteoclastogenesis and bone erosion. In animal models of inflammatory arthritis, mice deficient in IL-17 are less susceptible to development of disease. The list of IL-17-secreting cells is rapidly growing, and mast cells have been suggested to be a dominant source of IL-17 in inflammatory joint disease. However, many other innate sources of IL-17 have been described in both inflammatory and autoinflammatory conditions, raising questions as to the role of mast cells in orchestrating joint inflammation. This article will critically assess the contribution of mast cells and other cell types to IL-17 production in the inflammatory milieu associated with inflammatory arthritis, understanding of which could facilitate targeted therapeutic approaches. © 2013 Macmillan Publishers Limited. All rights reserved.
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Background Exposure to air pollutants, including diesel particulate matter, has been linked to adverse respiratory health effects. Inhaled diesel particulate matter contains adsorbed organic compounds. It is not clear whether the adsorbed organics or the residual components are more deleterious to airway cells. Using a physiologically relevant model, we investigated the role of diesel organic content on mediating cellular responses of primary human bronchial epithelial cells (HBECs) cultured at an air-liquid interface (ALI). Methods Primary HBECs were cultured and differentiated at ALI for at least 28 days. To determine which component is most harmful, we compared primary HBEC responses elicited by residual (with organics removed) diesel emissions (DE) to those elicited by neat (unmodified) DE for 30 and 60 minutes at ALI, with cigarette smoke condensate (CSC) as the positive control, and filtered air as negative control. Cell viability (WST-1 cell proliferation assay), inflammation (TNF-α, IL-6 and IL-8 ELISA) and changes in gene expression (qRT-PCR for HO-1, CYP1A1, TNF-α and IL-8 mRNA) were measured. Results Immunofluorescence and cytological staining confirmed the mucociliary phenotype of primary HBECs differentiated at ALI. Neat DE caused a comparable reduction in cell viability at 30 or 60 min exposures, whereas residual DE caused a greater reduction at 60 min. When corrected for cell viability, cytokine protein secretion for TNF-α, IL-6 and IL-8 were maximal with residual DE at 60 min. mRNA expression for HO-1, CYP1A1, TNF-α and IL-8 was not significantly different between exposures. Conclusion This study provides new insights into epithelial cell responses to diesel emissions using a physiologically relevant aerosol exposure model. Both the organic content and residual components of diesel emissions play an important role in determining bronchial epithelial cell response in vitro. Future studies should be directed at testing potentially useful interventions against the adverse health effects of air pollution exposure.
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Objective. To assess the genetic association between secretor status and ankylosing spondylitis (AS). Methods. A restriction digest method for determining secretor status was developed; 166 patients with AS and 216 healthy British white controls were typed for secretor status using this method. Results. The frequency of nonsecretors among patients with AS (47/166, 28%) was not significantly different from controls (72/216, 33%). Conclusion. Secretor status does not influence susceptibility to AS.
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Adult male bonnet monkeys exhibit nychthemeral rhythms in testosterone (T) secretion but the precise role of this heightened level of T secretion in regulating spermatogenesis is not known. Intranasal administration of microdoses (500 mu g or 250 mu g/day) of Norethisterone (IN-NET) to adult monkeys (n = 6) at 1600 h each day selectively and completely suppressed the nocturnal surge levels of serum T. Concomitant with this was a significant reduction (P<0.01) in serum LH but not FSH levels. DNA flow cytometric analysis of testicular biopsy tissue showed by week 10 of IN-NET treatment an arrest in meiotic transformation of primary spermatocytes (4C) to round/elongate (1C/HC) spermatids and by week 20 there was a complete absence of 4C, 1C and HC cells (with a relative accumulation in 2C cells). The accumulated meiotic (4C) cells at week 10 showed an increase (>80%, P<0.01) in coefficient of variation and a decrease in intensity of DNA-bound ethidium bromide fluorescence, parameters characteristic of degenerating 'apoptotic' subpopulation of germ cells. While two monkeys exhibited acute oligozoospermia 4 became azoospermic by 20 weeks of IN-NET treatment. A complete, qualitative reversal in the regressive changes in spermatogenesis and near-normal sperm output were apparent at the end of a 20-week recovery phase. These data demonstrate that prolonged, selective suppression of nocturnal surge levels of serum T secretion exerts a primary effect on meiosis in spermatogenesis leading to oligo/azoospermic status in adult bonnet monkeys.
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Human chorionic gonadotropin (hCG), a heterodimeric glycoprotein hormone, is composed of an alpha subunit noncovalentlv associated with the hormone-specific beta subunit. The objective of the present study was recombinant expression of properly folded, biologically active hCG and its subunits using an expression system that could be used for structure-function studies while providing adequate quantities of the hormone for immunocontraceptive studies. We report here expression of biologically active hCG and its subunits using a yeast expression system, Pichia pastoris. The recombinant hGG alpha and hCG beta subunits were secreted into the medium and the levels of expression achieved at shake culture level were 24 and 2.7-3 mg/l secretory medium respectively. Go-expression of both subunits in the same cell resulted in secretion of heterodimeric hGG into the medium. The pichia-expressed hCG was immunologically similar to the native hormone, capable of binding to the LH receptors and stimulating a biological response in vitro. Surprisingly, the maximal response obtained was twice that obtained with the native hGG. The le level of expression of hCG achieved was 12-16 mg/l secretory medium and is expected to increase several-fold in a fermenter. Thus the Pichia expression system is capable of hyperexpressing properly folded, biologically active hGG and is suitable for structure-function studies of the hormone.
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Cholesterol is considered indispensible for the recruitment and functioning of integrins in focal adhesions for cell migration. However, the physiological cholesterol pools that control integrin trafficking and focal adhesion assembly remain unclear. Using Niemann Pick Type C1 (NPC) mutant cells, which accumulate Low Density lipoprotein (LDL)-derived cholesterol in late endosomes (LE), several recent studies indicate that LDL-cholesterol has multiple roles in regulating focal adhesion dynamics. Firstly, targeting of endocytosed LDL-cholesterol from LE to focal adhesions controls their formation at the leading edge of migrating cells. Other newly emerging literature suggests that this may be coupled to vesicular transport of integrins, Src kinase and metalloproteases from the LE compartment to focal adhesions. Secondly, our recent work identified LDL-cholesterol as a key factor that determines the distribution and ability of several Soluble NSF Attachment Protein (SNAP) Receptor (SNARE) proteins, key players in vesicle transport, to control integrin trafficking to the cell surface and extracellular matrix (ECM) secretion. Collectively, dietary, genetic and pathological changes in cholesterol metabolism may link with efficiency and speed of integrin and ECM cell surface delivery in metastatic cancer cells. This commentary will summarize how direct and indirect pathways enable LDL-cholesterol to modulate cell motility.
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Eleven cystic fibrosis children (mean age, 9.6 years) were chosen at random to participate in a study to observe the effects of concurrently stimulating gastric/duodenal bicarbonate secretion and inhibiting gastric acid secretion, using a methylated prostaglandin E1 analogue in patients with pancreatic insufficiency and taking pancreatic enzymes. Percentage fat absorption in 3-day stool collections were calculated before and after commencing therapy with misoprostol, 400 μg/day in divided doses. We found a significant reduction in fat output (14.7 ± 11.7 versus 7.5 ± 3.5 g/day, p < 0.05) in the study group as a whole and a significant reduction in steatorrhoeic level as a percentage of fat intake in all of the patients with abnormal base-line collections (23.1% versus 9.2% p < 0.002). We conclude that misoprostol should be considered in cystic fibrosis patients with steatorrhoea as a means of improving nutrient absorption. © 1988 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
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Eleven cystic fibrosis children (mean age, 9.6 years) were chosen at random to participate in a study to observe the effects of concurrently stimulating gastric/duodenal bicarbonate secretion and inhibiting gastric acid secretion, using a methylated prostaglandin E1 analogue in patients with pancreatic insufficiency and taking pancreatic enzymes. Percentage fat absorption in 3-day stool collections were calculated before and after commencing therapy with misoprostol, 400 μg/day in divided doses. We found a significant reduction in fat output (14.7 ± 11.7 versus 7.5 ± 3.5 g/day, p < 0.05) in the study group as a whole and a significant reduction in steatorrhoeic level as a percentage of fat intake in all of the patients with abnormal base-line collections (23.1% versus 9.2%, p < 0.002). We conclude that misoprostol should be considered in cystic fibrosis patients with steatorrhoea as a means of improving nutrient absorption.
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We evaluated serum cationic trypsinogen as a marker of exocrine pancreatic function in children without cystic fibrosis. The ability of this test to determine steatorrhoea of pancreatic origin, and its relationship to a wide range of exocrine pancreatic function were assessed. Serum trypsinogen was measured in 32 children with steatorrhoea, 10 with pancreatic and 22 with non-pancreatic causes. In patients with pancreatic steatorrhoea, serum cationic trypsinogen was 4·9±4·9 μg/l (mean ±SD), significantly below values in patients with non-pancreatic steatorrhoea (47·0±22·1 μg/l, p<0·001) and 50 control subjects (31·4±7·4 μg/l, p<0·001). Serum cationic trypsinogen values in patients with pancreatic steatorrhoea all fell below the lower limit of our control range and below all values for patients with non-pancreatic steatorrhoea. Serum cationic trypsinogen was also evaluated against pancreatic trypsin output in 47 patients (range 0·2-17·0 yr) who underwent a hormonal pancreatic stimulation test. In 17 patients, serum cationic trypsinogen was low (<-2SD or 16·6 μg/l), and associated with greatly impaired pancreatic trypsin output, ranging from 0-8% of mean normal trypsin output. Five of these 17 patients did not have steatorrhoea. In 30 patients with normal or raised serum cationic trypsinogen (≥16·6 μg/l), pancreatic trypsin output ranged from 15-183% of mean normal values. In conclusion, low serum cationic trypsinogen suggests severely impaired exocrine pancreatic function, with sensitivity extending above the steatorrhoeic threshold. In the presence of steatorrhoea, low serum cationic trypsinogen indicates a pancreatic aetiology. Normal serum cationic trypsinogen, however, does not exclude impaired pancreatic function, above the steatorrhoeic threshold.
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Serum immunoreactive cationic trypsinogen levels were determined in 99 control subjects and 381 cystic fibrosis (CF) patients. To evaluate the status of the exocrine pancreas all CF patients had previously undergone fecal fat balance studies and/or pancreatic stimulation tests. Three hundred fourteen CF patients had fat malabsorption and/or had inadequate pancreatic enzyme secretion (pancreatic insufficiency) requiring oral pancreatic enzyme supplements with meals. Sixty-seven CF patients did not have fat malabsorption and/or had adequate enzyme secretion (pancreatic sufficiency) and were not receiving pancreatic enzyme supplements with meals. Mean serum trypsinogen in 99 control subjects was 31.4 ± 14.8 /µg/hter (± 2 SD) and levels did not vary with age or sex. In CF infants (< 2 yr) with pancreatic insufficiency, mean serum trypsinogen was significantly above the non-CF values (p < 0.001). Ninety-one percent of the CF infants had elevated levels. Serum trypsinogen values in the pancreatic insuffi ient group declined steeply up to 5 years, reaching subnormal values by age 6. An equation was developed which described these age-related changes very accurately. Only six CF patients with pancreatic insufficiency had serum trypsinogen levels above the 95% confidence limits of this equation. In contrast, there was no age related decline in serum trypsinogen among the CF group with pancreatic sufficiency. Under 7 yr, serum trypsinogen failed to distinguish the two groups. In those over 7 yr of age, however, serum trypsinogen was significantly higher than the CF group with pancreatic insufficiency (p < 0.001), and 93% had values within or above the control range. In conclusion, serum trypsinogen appears to be a useful screening test for CF in infancy. Between 2 and 7 yr of age this test is of little diagnostic value. After 7 yr of age, serum trypsinogen can reliably distinguish between CF patients with and without pancreatic insufficiency.
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Objective: To assess the impact of feeding different amounts of sorghum ergot to sows before farrowing. Design: Fifty-one pregnant sows from a continually farrowing piggery were sequentially inducted into the experiment each week in groups of four to seven, as they approached within 14 days of farrowing. Diets containing sorghum ergot sclerotia within the range of 0 (control) up to 1.5% w/w (1.5% ergot provided 7 mg alkaloids/kg, including 6 mg dihydroergosine/kg) were randomly allocated and individually fed to sows. Ergot concentrations were varied with each subsequent group until an acceptable level of tolerance was achieved. Diets with ergot were replaced with control diets after farrowing. Post-farrowing milk production was assessed by direct palpation and observation of udders, and by piglet responses and growth. Blood samples were taken from sows on three days each week, for prolactin estimation. Results: Three sows fed 1.5% ergot for 6 to 10 days preceding farrowing produced no milk, and 87% of their piglets died despite supplementary feeding of natural and artificial colostrums, milk replacer, and attempts to foster them onto normally lactating sows. Ergot inclusions of 0.6% to 1.2% caused lesser problems in milk release and neo-natal piglet mortality. Of 23 sows fed either 0.3% or 0.6% ergot, lactation of only two first-litter sows were affected. Ergot caused pronounced reductions in blood prolactin, and first-litter sows had lower plasma prolactin than multiparous sows, increasing their susceptibility to ergot. Conclusion: Sorghum ergot should not exceed 0.3% (1 mg alkaloid/kg) in diets of multiparous sows fed before farrowing, and should be limited to 0.1 % for primiparous sows, or avoided completely.
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This study provides comprehensive documentation of silk production in the pest moth Helicoverpa armigera from gland secretion to extrusion of silk thread. The structure of the silk glands, accessory structures and extrusion apparatus are reported. The general schema of the paired silk glands follows that found for Lepidoptera. Morphology of the duct, silk press, muscle attachments and spigot are presented as a three-dimensional reconstruction and the cuticular crescent-shaped profile of the silk press is demonstrated in both open and closed forms with attendant muscle blocks, allowing advances in our knowledge of how the silk press functions to regulate the extrusion of silk. Growth of the spigot across instars is documented showing a distinctive developmental pattern for this extrusion device. Its shape and structure are related to use and load-bearing activity.