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993.
PTH is incriminated as an uraemic toxin involved in the pathogenesis of anaemia in chronic renal failure. This fact was the background of our present studies performed in 14 patients with noninflammatory acute renal failure (NARF). Plasma levels of erythropoietin (EPO) and parathyroid hormone (PTH) were estimated in the anuric/oliguric (a/o) and polyuric (p) phase of NARF. In the a/o phase plasma EPO levels were predominantly normal, although inappropriately low to the degree of anaemia. In 50% of patients with NARF episodic short-term increases of plasma EPO levels were noticed which were not caused by worsening of anaemia. In the p phase plasma EPO concentrations were in the normal range (17.9 +/- 3.3 mU/ml) in spite of the same degree of anaemia as in the a/o phase. Plasma PTH levels were significantly elevated during the a/o phase (1.14 +/- 0.1 ng/ml), with a tendency to decline in the p phase (0.87 +/- 0.2 ng/ml). No correlation was found between plasma EPO and PTH concentrations. Results presented in this study suggest presence of relative EPO deficiency both during the a/o and p phases of NARF. As plasma PTH levels were not significantly correlated with serum EPO concentrations, its role in the pathogenesis of suppressed EPO levels seems unproven. Results presented in this study suggest deterioration of the physiological feedback between EPO secretion and the magnitude of erythropoiesis in NARF. 相似文献
994.
Approximately 50% of the forearm vasodilatation to intra-arterial infusions of acetylcholine is mediated by endothelium-derived nitric oxide. These conclusions have been derived from venous occlusion plethysmographic measurements of total forearm blood flow during co-infusions of acetylcholine and NG-monomethyl-L-arginine (L-NMMA), an inhibitor of nitric oxide synthase. Since venous occlusion plethysmography measures total limb blood flow, the relative proportion of the measurement from skin cannot be determined precisely. To determine the effects of acetylcholine on skin specifically, we have used laser Doppler flowmetry to measure vascular responses to local iontophoresis of acetylcholine in the forearm of normal male volunteers. To elucidate the possible mechanisms of cutaneous vasodilatation to acetylcholine, vascular responses were measured before and after systemic inhibition of prostanoid production and nitric oxide synthesis by oral aspirin (600 mg daily for 3 days) and intravenous L-NMMA (3 mg/kg for 60 min), respectively. After aspirin administration, dose-dependent vascular responses to acetylcholine were reduced significantly by approximately 53% (p < 0.005, ANOVA). In contrast, intravenous L-NMMA appeared to have no significant effect on cutaneous vascular responses to acetylcholine. While the role of nitric oxide is uncertain, vasodilatation to acetylcholine in the forearm skin is mediated largely by a prostanoid-dependent mechanism. Assessment of cutaneous vascular responses to iontophoresis of acetylcholine may, therefore, be useful in diseases where abnormal endothelium-dependent prostanoid function has been implicated. 相似文献
995.
Heparin inhibits leukocyte rolling in pial vessels and attenuates inflammatory changes in a rat model of experimental bacterial meningitis 总被引:1,自引:0,他引:1
JR Weber K Angstwurm T Rosenkranz U Lindauer D Freyer W Bürger C Busch KM Einh?upl U Dirnagl 《Canadian Metallurgical Quarterly》1997,17(11):1221-1229
Heparin is a natural proteoglycan that was first described in 1916. In addition to its well characterized effect on blood coagulation, it is becoming clear that heparin also modulates inflammatory processes on several levels, including the interference with leukocyte-endothelium interaction. Anecdotal observations suggest a better clinical outcome of heparin-treated patients with bacterial meningitis. The authors demonstrate that heparin, a glycosaminoglycan, inhibits significantly in the early phase of experimental pneumococcal meningitis the increase of 1) regional cerebral blood flow (125 +/- 18 versus 247 +/- 42%), 2) intracranial pressure (4.5 +/- 2.0 versus 12.1 +/- 2.2 mm Hg), 3) brain edema (brain water content: 78.23 +/- 0.33 versus 79.49 +/- 0.46%), and 4) influx of leukocytes (571 +/- 397 versus 2400 +/- 875 cells/microL) to the cerebrospinal fluid compared with untreated rats. To elucidate the possible mechanism of this observation, the authors investigated for the first time leukocyte rolling in an inflammatory model in brain venules by confocal laser scanning microscopy in vivo. Heparin significantly attenuates leukocyte rolling at 2, 3, and 4 hours (2.8 +/- 1.3 versus 7.9 +/- 3.2/100 microm/min), as well as leukocyte sticking at 4 hours (2.1 +/- 0.4 versus 3.5 +/- 1.0/100 microm/min) after meningitis induction compared with untreated animals. The authors conclude that heparin can modulate acute central nervous system inflammation and, in particular, leukocyte-endothelium interaction, a key process in the cascade of injury in bacterial meningitis. They propose to evaluate further the potential of heparin in central nervous system inflammation in basic and clinical studies. 相似文献
996.
INTRODUCTION: Chondromas are rare intracranial tumors. The authors present two cases of intracranial intradural chondroma, one originating from the falx cerebri and the other from the dura mater of the convexity. METHOD AND RESULTS: Diagnostic procedures, including magnetic resonance imaging, and surgical findings are described. In both cases, pre-operative diagnosis could have been at least suspected, and the tumor was completely removed, without recurrence after a follow-up of many years. The pathogenesis and pathological findings are discussed, and cases from the literature are reviewed. CONCLUSION: Benign intradural chondroma has a good prognosis, with no recurrence after surgical excision in most cases. 相似文献
997.
Defensive individuals have been shown to differ from nondefensive individuals on a number of physiological and behavioral measures. We report two studies on observers' inferences of defensiveness, and the contribution of communication channels in the inference of defensiveness. Observers judged high and low state anxious segments of high and low trait anxious defensive and nondefensive individuals. Accurate assessments were made of (a) defensiveness, (b) state anxiety, and (c) trait anxiety: Individuals with higher levels of each variable were perceived as more anxious compared with the lower level. Effects for defensiveness and state anxiety were greater in audio-only segments, while effects for trait anxiety were greater in video-only segments. Inferences of defensiveness were greater at higher levels of state anxiety and trait anxiety. Low trait anxious defensive individuals were perceived as more anxious than the true low trait anxious. Results for defensiveness and trait anxiety were replicated in Study 2, and observers' perceptions of state anxiety matched individuals' self-reports: Defensive individuals with maximal differences between high and low state anxiety were seen as more anxious in high state anxiety, while defensive individuals with minimal differences between high and low state anxiety were regarded as less anxious in high state anxiety. 相似文献
998.
ML Barr FA Schenkel RG Cohen KM Chan CC Marboe JA Hagen RG Barbers VA Starnes 《Canadian Metallurgical Quarterly》1996,20(10):1110-1111
As the recipient list for patients requiring lung transplantation continues to increase, cadaveric donor lung availability has remained static. Our experience with utilizing lobes from living related donors for bilateral pulmonary transplantation in 20 patients has yielded a 75% survival at 1 year follow-up. Morbidity and mortality have been predominately due to infection. Rejection episodes have been mild and unilateral and have responded to augmented corticosteroids. Pulmonary function tests in the recipients tend to improve steadily during the first year postoperatively, and the patients have excellent functional capacity. There have been no significant complications in the donors. On the basis of our clinical experience, we have found that bilateral lobar transplantation utilizing living related donors has resulted in organ availability that can be lifesaving in critically ill patients and can provide a good alternative in certain noncritical, deteriorating patients. 相似文献
999.
MR Stegman KM Davies RP Heaney RR Recker JM Lappe 《Canadian Metallurgical Quarterly》1996,6(2):130-135
A population survey was conducted to determine the incidence of injuries among preschoolers and their risk factors. A systematic sample (15%, n = 4540) of families with at least one child aged 0-5 years in 1991 living in the Canton of Vaud (Switzerland) received a mailed questionnaire in February 1992. There were 5827 eligible children in the sample. The response rate was 67.5% after two recall mailings. Injuries were defined as those from all causes with at least one physician contact in 1991. The overall incidence was 224 injuries per 1000 children (95% CI [= confidence intervall]: 211-237); 188 per 1000 children were injured over 1 year (95% CI: 176-200, n = 746), of whom 16.5% (n = 123) had 32 injuries. Falls represented 66% of all injuries, followed by burns (8%) and poisonings (5%). The proportion of hospitalized cases was 4.8% and the population incidence of hospitalization due to injury was 10.8/1000 children. Socioeconomic factors did not influence the occurrence of injuries. CONCLUSION: The measured incidence of injuries among preschoolers is among the highest in developed countries. Practitioners could contribute more effectively to injury prevention through routine information and counselling of parents from all social backgrounds. 相似文献
1000.