摘要:

The alveolar epithelial cells of the lower respiratory tract are exposed continuously to injurious agents, including oxygen radicals. The type II alveolar epithelial cell is critically important to the normal function of the lung, because it is responsible for synthesis of surfactant and other essential duties. In the current investigation, the authors documented the loss of intracellular adenosine triphosphate (ATP) after exposure of the cells to sublethal concentrations of hydrogen peroxide (H2O2) and hypochlorous acid. Subsequent experiments attempted to alleviate or prevent this oxidant mediated loss of ATP by preincubating the cells with either glutathione or N-acetyleysteine (NAC). Initially, it was determined that exposure of the type II cells to 250 μM hypochlorous acid or 250 μM H2O2for 1 hour each would cause significant loss of type II cell ATP. However, preincubation with glutathione (1,000 μM) inhibited the loss of ATP after both exposure to 250 μM H2O2(24 ± 3% loss of ATP without glutathione compared with 13 ± 2% loss with glutathione,P< 0.05), and 250 μM hypochlorous acid (12 ± 2% loss of ATP without glutathione compared with 1 ± 1% increase of ATP with glutathione). Similar results were obtained using NAC (2 mg/mL) after exposure to 250 μM H2O2(23 ± 2% loss of ATP without NAC compared with a 4 ± 3% loss of ATP with NAC). This study demonstrates that exogenous glutathione and NAC are able to protect type II cells from oxidant mediated sublethal injury and loss of intracellular ATP stores.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

In this article, the author discusses the prevalence of insulin autoantibodies (IAA) and endogenous insulin secretion in Saudi patients at the onset of diabetes. A positive result, defined as a value greater then 3 SD above the mean binding of normal, was found in 8 (7.6%) of 105 of the patients with diabetes and in 3 (5.7%) of 53 of the healthy control subjects. The relation between the presence of IAA and the pancreatic beta cell secretory activity was studied by determining the levels of insulin and C-peptide in the fasting state and 6 minutes after intravenous injection of 1 mg glucagon. All the IAA positive subjects had a response to glucagon stimulation test. A positive correlation was found between basal and after stimulation for both insulin and C-peptide (r = 0.79,P< 0.001; r = 0.85,P< 0.001 for insulin and r = 0.76,P< 0.001; r = 0.81,P< 0.001 for C-peptide, respectively). Therefore, the current finding indicates that there is no direct effect of IAA on the pancreatic beta cell potential activity in Saudi patients with diabetes at the time of diagnosis, suggesting further that these patients have no insulin deficiency or have mild insulin dependency.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Atrial natriuretic factor (ANF), consisting of amino acids 99–126 of the 126 amino acid ANF prohormone, increases cyclic guanosine monophosphate (GMP) (thought to be the mediator of its physiologic effects) in plasma and urine of human subjects. Long-acting natriuretic peptide, vessel dilator, and kaliuretic peptide, consisting of amino acid 1–30, 31–67, and 79–98, respectively, of this same prohormone have natriuretic, diuretic, kaliuretic, and blood pressure lowering properties in humans. These three new peptide hormones increase cyclic GMP in vitro but were never investigated to determine whether they also cause extrusion of cyclic GMP from cells, resulting in an increase of cyclic GMP in plasma and/or urine. Infusion of each of these peptide hormones at their 100 ng/kg body weight/min concentrations for 60 minutes into healthy humans resulted in a sevenfold increase in cyclic GMP in plasma and urine secondary to ANF, but no significant increase secondary to the other atrial peptide hormones. Based on the current data, ANF has a unique effect on the metabolism of cyclic GMP, causing it to be extruded from the cell, whereas the other three atrial peptides represent the more classical metabolism of cyclic GMP via cyclic GMP phophodiesterases.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Three decades ago, penicillin-resistant strains ofStreptococcus pneumoniaewere first reported. Since then, myriad penicillin resistant strains ofS. pneumoniaehave been identified worldwide and in the United States. No resistant or intermediate resistant strains have been reported in West Virginia because testing has not been done. Between 1983 and 1994, the authors' surveillance of invasive pneumococcal disease in metropolitan Huntington, West Virginia, identified 356 pneumococcal strains from blood and other usually sterile sites, including 110 strains belonging to serotypes 6, 9, 14, 19, and 23, the main serotypes exhibiting penicillin resistance. The authors tested these serotypes for penicillin susceptibility by the E-test. Sixteen (14.5%) strains of types 6, 9, 14, 19, and 23 exhibited intermediate resistance to penicillin. No highly resistant strains were identified. Most of the intermediate resistant strains of types 9, 14, and 23 were detected in epidemiologic years 1992–1994. The increasing number of intermediate resistant penicillin strains signals the need for routine testing of invasive pneumococcal strains for penicillin susceptibility and necessitates appropriate antibiotic usage.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Hypertensive intracerebral hemorrhage (ICH) usually is a one-time event, despite multiple microaneurysms and widespread lipohyalinosis in the cerebral perforating vessels. Contrary to this belief, the authors describe five patients with recurrent hypertensive ICH. Of 105 patients of spontaneous ICH, 5 had recurrence. All were patients with poorly controlled hypertension whose age ranged from 25–62 years; 3 were women. Four patients had two episodes of ICH, and one had three. Of 11 hemorrhages, 9 were ganglionic, one was pontine, and one was lobar. Recurrence of hypertensive ICH seems to be commoner than reported in the literature, and it may be attributed to poor control of blood pressure.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Systemic lupus erythematosus occurs with much greater frequency in females than in males, and in some reports, researchers suggested that treatment with androgenic hormones might have therapeutic effects in this disease. The authors report a case of systemic lupus erythematosus in a hypogonadal male with Klinefelter's syndrome who was treated with testosterone in doses sufficient to normalize the serum level of this hormone to the adult male range. Hematologic and serologic abnormalities, including elevated levels of anti-DNA antibodies and depressed complement levels, returned to normal within 9 months of increasing the testosterone dose. The findings in this patient indicate that androgenic steroids can exert significant effects on immune parameters, and suggest that effects of androgens on the immune system may contribute to the sexual dimorphism of autoimmune disease.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Analgesic nephropathy has long been considered a potentially preventable cause of renal disease. Early reports were described in patients who consumed analgesics containing phenacetin. In recent data, the removal of phenacetin from analgesic preparations resulted in a reduction in analgesic-induced end stage renal disease in Europe and Australia. However, a reduction in the incidence of analgesic nephropathy has not occurred uniformly, suggesting that phenacetin is not the sole cause. Current data raise concerns regarding adverse renal effects of acetaminophen and nonsteroidal antiinflammatory drugs. Aspirin taken alone may be of least concern. The diagnosis of analgesic nephropathy is suggested in subjects with chronic renal failure, a history of daily consumption of analgesic preparations, small bumpy kidneys, and renal papillary necrosis or chronic interstitial nephritis. However, the spectrum of disease may be changing, because these agents also may increase the risk of cardiovascular disease and chronic renal disease due to nephrosclerosis, glomerulonephritis, and diabetes mellitus. Potential pathogenetic mechanisms in analgesic nephropathy include direct cellular injury induced by analgesies, prostaglandin inhibition with reduction or redistribution of renal blood flow, and interesting new concepts regarding the role of caffeine in increasing oxygen demand and reducing oxygen supply in the medulla. The primary goal of therapy is discontinuation of analgesic consumption. Because of the association between analgesic intake and uroepithelial tumors, surveillance of patients for neoplasm is suggested.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

A patient with a markedly elevated serum phosphorus level (23.9 mg/dL) is described, followed by a brief review of severe hyperphosphatemia. Elevated serum phosphorus levels may be artifactual or true. True hyperphosphatemia is usefully subdivided according to (a) whether phosphorus is added to the extracellular fluid from a variety of exogenous or endogenous sources, or (b) whether the urinary excretion of phosphorus is reduced from either decreased glomerular filtration or increased tubular reabsorption. Severe hyperphosphatemia, defined herein as levels of 14 mg/dL or higher, is almost invariably multifactoria—usually resulting from addition of phosphorus to the extracellular fluid together with decreased phosphorus excretion. The hyperphosphatemia of the patient described herein appeared to result from a combination of dietary phosphorus supplementation, acute renal failure, acute pancreatitis, and ischemic bowel disease, complicated by lactic acidosis.

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0002-9629    

出版商:OVID    

年代:1995

数据来源: OVID