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The conduct of clinical trials is a complicated process involving a myriad of regulations and enforcement entities. To protect the rights and welfare of study participants, a system of oversight bodies called institutional review boards has been established in the US. This article describes how institutional review boards work and explains what clinical researchers need to know about federally mandated human subject protection requirements.
A progressive decline in islet function is a major obstacle to the success of islet transplantation. The cause of this decline in islet function is unclear, but immunosuppressive agents may contribute. Insulin-like growth factor-I (IGF-I) and betacellulin are important for islet cell survival and/or proliferation. In the present study, we performed studies in INS-1 cells and murine islets to define the effect of IGF-I and betacellulin on progression of islet cells through the cell cycle and the impact of immunosuppressive agents. Treatment of INS-1 cells for 24 hours with 20 ng/mL betacellulin or 50 ng/mL IGF-I increased cells in S phase by ∼2-fold. Treatment of INS-1 cells with IGF-I or betacellulin also increased cyclin D1 expression and nuclear exclusion of the cyclin-dependent kinase inhibitors p21Cip1 and p27Kip1. In INS-1 cells and islets, betacellulin- and IGF-I increased Akt, extracellular signal-related kinase, and p70S6 kinase phosphorylation. Rapamycin, an immunosuppressant which inhibits mammalian target of rapamycin, inhibited the increase in p70S6 kinase phosphorylation stimulated by betacellulin- and IGF-I in INS-1 cells. Rapamycin also inhibited betacellulin- and IGF-I-induced entry of cells into S phase and 5′-Bromo-2′-deoxyuridine incorporation as well as the effect of betacellulin and IGF-I on cyclin D1 expression and nuclear exclusion of p21Cip1 and p27Kip1. Together, these data suggest that the effect of betacellulin and IGF-I on islet cell growth and proliferation is mediated, in part, via signaling through mammalian target of rapamycin. As rapamycin is used to treat islet transplant recipients, these results suggest that rapamycin could have deleterious effects on islet proliferation and function over time.
The aim of the present study was to evaluate levels of neutrophil gelatinase-associated lipocalin (NGAL), a stress protein increased after renal and systemic stimuli, in a cohort of 15 patients with severe proteinuria secondary to idiopathic membranous nephropathy and conserved renal function. Neutrophil gelatinase-associated lipocalin levels and the fractional excretion of this protein were higher in patients than in healthy controls. Furthermore, a close correlation was found between serum NGAL and urinary (uNGAL) (
We studied 323 patients with heart failure (258 men/65 women; age, 70.8 ± 11.5 years) followed-up for 11.9 ± 6.6 months.
The
No significant difference in ACE polymorphism genotype distribution and allele frequency according to N-terminal pro-brain natriuretic peptide tertiles was observed. At multinomial regression analysis,
This study suggests that
The effects of long-term high-dose corticosteroids on bone mineral density (BMD) are clear, but the effects of low-dose corticosteroids in patients with rheumatoid arthritis (RA) remain controversial. The aim of this study was to assess the effects of low-dose corticosteroids on BMD in patients with RA.
The authors surveyed randomized controlled studies that examined the effects of low-dose corticosteroids on BMD in patients with RA using MEDLINE and the Cochrane Controlled Trials Register and by performing manual searches. Data were collected on BMD (end-of-period or change-from-baseline) after longest recorded treatment durations. Meta-analysis was performed using a random effects model; outcomes are presented as standardized mean differences (SMDs).
Seven studies were included in this meta-analysis, which included 7 studies on lumbar BMD meta-analysis and 6 studies on femur BMD meta-analysis. Corticosteroids resulted in a moderate worsening in lumbar BMD compared with controls (SMD = −0.483; 95% confidence interval [CI], −0.815 to −0.151,
This meta-analysis shows BMD loss after low-dose corticosteroid treatment in patients with RA. These findings have practical implications for the long-term management of patients with RA on low-dose corticosteroids.
In 2004, the American College of Physicians joined with the National Library of Medicine in an effort to help patients find reliable health information free of commercial bias at the Web site
A 27-item questionnaire developed by the American College of Physicians Foundation was distributed between January and May 2005 to a convenience sample of 893 adult patient volunteers attending 34 internal medicine practices across the United States.
The questionnaire revealed that although most patients (55%) routinely look up medical information, only 43% had used
Patients who used the
A 27-year-old female with sickle cell disease (HbSS) was admitted presenting with severe bone pain and fever. She refused blood transfusions throughout her hospital stay for religious reasons. During the first 9 days of admission, the patient's clinical presentation became worse despite antibiotic coverage. The patient exhibited pulmonary infiltrates and mild hypertension, increased pain, fever, tachycardia, and decreased hematocrit. After day 8 of admission, her laboratory findings and clinical presentation indicated that her disease was markedly worse. With the patient's consent, inhaled nitric oxide therapy (iNO = 40 ppm) was initiated and continued for 3.2 days. After a full day of iNO therapy, the clinical improvement was limited to temperature normalization and stabilization of her hemoglobin levels. After 2 more days of iNO therapy, her multiple clinical complications of sickle cell disease improved markedly and she was discharged 3 days after completion of the iNO treatment. The complications of NO therapy, such as methemoglobulinemia or decreased blood pressure, were not detected during the iNO therapy. Although limited to a single individual, we propose that our anecdotal experience suggests that iNO therapy may (i) need to be continuous for several days to provide improved benefits, (ii) treat several of sickle cell complications besides pain, and (iii) exhibit few complications. These proposals need to be confirmed in clinical trials.
