464 research outputs found
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Multiplication stimulating activity (MSA) can substitute for insulin to stimulate the secretion of testicular transferrin by cultured sertoli cells
Both MSA and insulin were found to stimulate transferrin production in cultured Sertoli cells to the same extent in the absence or presence of follitropin, testosterone, or retinol. Sertoli cells were responsive to 30-fold lower concentrations of MSA than of insulin. MSA and insulin together stimulated transferrin secretion to the same extent as either hormone alone. These results, and what is presently understood about the relationship of MSA and insulin, suggest that insulin can substitute for the action of an MSA-like peptide in the stimulation of testicular transferrin secretion by Sertoli cells
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Secretion of Testicular Transferrin by Cultured Sertoli Cells is Regulated by Hormones and Retinoids
Sertoli Cells Synthesize and Secrete a Ceruloplasmin-Like Protein
Sertoli cells synthesize and secrete a ceruloplasmin-like protein (testicular ceruloplasmin) that is immunologically similar to serum ceruloplasmin. Rat serum ceruloplasmin was purified and an antiserum was produced to the purified protein which specifically immunoprecipitated a 130,000 dalton protein from rat serum. This ceruloplasmin antiserum was found to also immunoprecipitate a 130,000 dalton protein synthesized and secreted by Sertoli cells. The presence of a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was required during the immunoprecipitation procedure to prevent the proteolytic degradation of testicular ceruloplasmin. Immunoprecipitation of proteins secreted by Sertoli cells with an antiserum to rat serum proteins was found to precipitate two proteins, testicular ceruloplasmin and testicular transferrin
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Secretion of growth factors and other regulatory agents by Sertoli cells
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Analysis of Sertoli Cell-Secreted Proteins by Two-Dimensional Gel Electrophoresis
The [35S]methionine-labeled proteins secreted from cultured Sertoli cells were analyzed by two-dimensional gel electrophoresis and fluorography. Major polypeptides which were resolved by this procedure were designated by number and further analyzed. Many of these major polypeptides appeared as a series of spots which corresponded to charge isomers. Two of these polypeptides (5 and 6) were shown to be acidic, glycosylated and to comprise the subunits of a dimeric protein of molecular weight 70,000. Some of the polypeptides (4a and 5a) were shown to be secreted from testicular peritubular cells which contaminated the Sertoli cell cultures. However, many of the polypeptides (1,2,3,4,5,5b and 6) were specifically secreted from the Sertoli cells. The fluorogram of the secreted polypeptides obtained from cultured Sertoli cells from 20- or 60-day-old rats were similar to each other but differed from the pattern of polypeptides which were secreted from cultures of Sertoli cells from 10-day-old rats. Polypeptide 3 was identified by immunoprecipitation as testicular transferrin and the synthesis of polypeptide 3 was stimulated when the Sertoli cells were cultured in the presence of follicle-stimulating hormone (FSH), insulin, testosterone and retinol
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The interaction of Sertoli cell glycoproteins with germinal cells in the testis
A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.
Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCell® Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P < .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ≤ .05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG
Operationalizing Frailty in the Atherosclerosis Risk in Communities Study Cohort
Background: Factors that may contribute to the development of frailty in late life have not been widely investigated. The Atherosclerosis Risk in Communities (ARIC) Study cohort presents an opportunity to examine relationships of midlife risk factors with frailty in late life. However, we first present findings on the validation of an established frailty phenotype in this predominantly biracial population of older adults.
Methods: Among 6,080 participants, we defined frailty based upon the Cardiovascular Health Study (CHS) criteria incorporating measures of weight loss, exhaustion, slow walking speed, low physical activity, and low grip strength. Criterion and predictive validity of the frailty phenotype were estimated from associations between frailty status and participants' physical and mental health status, physiologic markers, and incident clinical outcomes.
Results: A total of 393 (6.5%) participants were classified as frail and 50.4% pre-frail, similar to CHS (6.9% frail, 46.6% pre-frail). In age-adjusted analyses, frailty was concurrently associated with depressive symptoms, low self-rated health, low medication adherence, and clinical biomarker levels (ie, cholesterol, hemoglobin A1c, white blood cell count, C-reactive protein, and hemoglobin). During 1-year follow-up, frailty was associated with falls, low physical ability, fatigue, and mortality.
Conclusions: These findings support the validity of the CHS frailty phenotype in the ARIC Study cohort. Future studies in ARIC may elucidate early-life exposures that contribute to late-life frailty
Prediabetes and Diabetes Are Associated With Arterial Stiffness in Older Adults: The ARIC Study
To determine whether prediabetes and diabetes in older adults are associated with arterial stiffness measured in central and peripheral arteries and to examine characteristics that modify these associations
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