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The objective of this study was to compare the properties of single smooth muscle cells enzymatically dispersed from the dog mesenteric arteries to the properties of similar cells functioning in tissue strips. The isolated cells remained relaxed in nominally Ca(2+)-free medium for about 1-2 h after exposure to 1 mM Ca2+ and like intact mesenteric artery rings did not contract spontaneously. Enzymatically dispersed cells maintained all the characteristic morphological features observed in strips of muscle prior to isolation except that the amorphous materials covering the smooth muscle cell surfaces (basal lamina) were absent after enzymatic dispersion. Addition of 100 mM KCl to these vascular muscle cells elicited maximal shortening in the presence but not in the absence of extracellular Ca2+ and KCl-induced cell shortening was prevented by 10(-7) M nifedipine indicating the presence of functional voltage-operated Ca2+ channels. However, in contrast to the vascular muscle strips, in which graded contractile responses were observed with increasing KCl concentrations, isolated vascular muscle cells underwent nearly maximal contraction at concentrations as low as 15 mM KCl. Both intact tissue and isolated cell preparations responded similarly to phenylephrine in a concentration-dependent manner and the responses were blocked by prazosin. In contrast to muscle strips, the isolated cells did not shorten in response to phenylephrine in Ca(2+)-free medium. Isolated muscle shortened in the presence of sarcoplasmic reticulum selective Ca2+ transport ATPase inhibitors, cyclopiazonic acid or thapsigargin. Ryanodine also caused contraction. We conclude that enzymatically dispersed smooth muscle cells from dog mesenteric arteries are potentially useful for studies of the regulation of smooth muscle contractility, but have significantly increased sensitivity to external K+, implying an altered membrane potential or voltage dependence of ion channels. Their impaired ability to contract to phenylephrine in Ca(2+)-free medium implies some alteration in intracellular Ca2+ stores of their coupling to cellular activation. These differences will affect how the data obtained from freshly isolated enzymatically dispersed vascular muscle cells may be extrapolated to cell studies in intact tissues. 相似文献
96.
Chang DK Kim JW Kim BK Lee KL Song CS Han JK Song IS 《World journal of gastroenterology : WJG》2005,11(42):6587-6592
AIM: To study the clinical significance of minimal ascites, which was only defined by the CT and whose nature was not determined preoperatively, in the relationship with the peritoneal carcinomatosis. METHODS: The medical records and the dynamic CT films of 118 patients with gastric cancer were reviewed. Factors associated with peritoneal carcinomatosis were analyzed in 40 patients who had CT-defined ascites of which the nature was surgically confirmed. RESULTS: Only 12.5-25% of the CT-defined minimal ascites, whose volume was estimated to be less than 50 mL, were associated with peritoneal carcinomatosis. When the estimated CT-defined ascitic volume was 50 mL or more, peritoneal carcinomatosis was identified in 75-100%. When CT-defined lymph node enlargements were not found beyond the regional gastric area, perigastric invasions were not suspected, and the size of tumor was less than 3 cm, peritoneal carcinomatosis seemed significantly less accompanied at the univariate analysis. However, except for the minimal volume of CT-defined ascites in comparison with the mild or more, other factors were not confirmed multivariately. CONCLUSION: In the patients with gastric cancer, CT-defined minimal ascites alone is rarely associated with peritoneal carcinomatosis, if it does not accompany other signs suggestive of malignant seeding. Therefore, consideration of active curative resection should not be hesitated, if CT-defined minimal ascites is the only delusive sign. 相似文献
97.
Anomalous origin of the left main coronary artery from the right sinus of Valsalva or the right coronary artery is a rare coronary anomaly. This anomaly has been associated with sudden cardiac death in younger patients, depending on its course relative to the pulmonary artery. The authors report this rare anomaly in two patients. It presented as unstable angina in the first patient with a septal course. In the second patient, it presented as syncope with an anterior free wall course and absent left circumflex artery. A septal course causing unstable angina has not been reported previously. 相似文献
98.
L. C. K. Low E. Y. W. Kwan Y. J. Lim A. C. W. Lee C. F. Tarn K. S. L. Lamf 《Clinical endocrinology》1995,42(4):359-363
OBJECTIVE Despite regular transfusion and desferoxamine treatment, growth failure Is commonly seen In adolescent children with β-thalassaemla major. The growth failure has been thought to be due to GH resistance rather than GH deficiency. We Investigated the effect of GH on short non-GH deficient children with β-thalassaemia. DESIGN Recombinant human GH was given In a dose of 0-14IU/kg/day subcutaneously in an open study. PATIENTS Fifteen prepubertal Chinese children with β-thalassaemia major (ranging from 7.16 to 14.7 years In age) with height ?1.5 SD or more below the population mean for age and a growth velocity of less than 5 cm/year were treated with growth hormone for one year. All children had peak GH response >15mlU/l to insulin Induced hypoglycaemia and normal thyroid function and adrenal reserve. MEASUREMENTS Anthropometric measurements were performed every 3 months. Morning urine was tested twice weekly for glycosuria. Blood count, renal and liver function tests, fasting blood glucose, IGF-I and fructosa-mine levels were assessed at entry and every 3 months during treatment. Fasting Insulin was measured before and after 3 and 12 months of GH treatment. Skeletal maturity was assessed before and after one year of treatment. RESULTS Treatment was stopped in two children after 6 months because of poor growth response and noncompliance with treatment and In one child at 9 months because of bone marrow transplantation. In the 13 children, the growth velocity increased from 3.6±0.7 cm/year to 8±1.2 cm/year after one year of GH treatment (P<0.001). IGF-I was low before treatment (10.1±2.7nmol/l), rising significantly to 15.8±4.8, 18.4±4.6, 19.3±6.4 and 21.9±7.5nmol/l at 3, 6, 9 and 12 months of treatment (P<0.005). The mean pretreatment bone age in the 13 children was 9.58±1.41 years and increased to 10.53±1.43 years after one year of treatment (ΔBA/CA 0.95±0.3 years). None of the patients developed glycosuria or hypertension. There was no significant change in blood count, renal and liver function, thyroid function, fasting blood glucose or insulin concentrations during treatment. CONCLUSION Growth failure In these children with normal GH reserve and low serum IGF-I concentrations would suggest GH insensltlvity. Supraphyslologlcal doses of exogenous GH can cause a significant increase In serum IGF-I levels and a significant Improvement in short-term growth of short children with β-thalassaemia major. 相似文献
99.
Single daily-dose ofloxacin monotherapy for Mycobacterium fortuitum sternotomy infection 总被引:2,自引:0,他引:2
Infection of sternotomy wounds due to Mycobacterium fortuitum-chelonei complex postoperatively was noted in ten patients in 1987 and six patients in 1988 in our hospital. The first ten patients were treated with a combination of ofloxacin and amikacin, successfully in nine. In the six later patients, five had M fortuitum infection and one had M chelonei infection. In those five we used single daily-dose ofloxacin, 600 mg, in three with rapid clinical response and bacteriologic cure. The MIC of ofloxacin for these three isolates ranged from 0.32 mg/L to 1.25 mg/L, and peak serum level of ofloxacin assessed by high-performance liquid chromatography ranged from 4.1 mg/L to 8.0 mg/L. Monotherapy with ofloxacin is recommended for M fortuitum infection of wound and soft tissue, with in vitro susceptibility studies as a guide, pending further reinforcing clinical evidence. 相似文献
100.
Kang MS Park DI Jeen YT Keum B Choi JH Jung SA Kim HS Kim YH Kim WH Kim TI Kim HJ Yang SK Myung SJ Byeon JS Lee MS Jung IK Chung MK Choi H Han DS Song JS 《International journal of colorectal disease》2008,23(2):171-176
Background/aims The possibility of proximal lesion without distal polyps is a weak point of sigmoidoscopic colon cancer screening, but the
clinical significance of distal findings for advanced proximal neoplasm (APN) is uncertain. The aim of this study was to assess
the significance of a distal finding as a predictor of APN.
Materials and methods Asymptomatic patients ≥50 years old were enrolled from among patients who underwent polypectomy at 11 tertiary medical centers
during the Korean Association for the Study of Intestinal Disease prospective study conducted between July 2003 and March
2004. Polyps located distal to the splenic flexure were defined as distal polyps. An advanced neoplasm was defined as a polyp
of ≥10 mm in size, and/or with villous features, and/or with high-grade dysplasia, or invasive cancer. Age, gender, and distal
polyp size, appearance, and histology were analyzed as risk factors of APN. The sensitivity and positive predictive value
of distal polyps for APN were calculated.
Results Data from 826 patients were analyzed. Mean patient age was 60.1 years (range 50–86), and 71.3% were men. APN was found in
98 patients, and 45 (45.9%) patients had no distal polyps. Risk factors of APN were a male gender, distal polyp size, and
an advanced distal neoplasm. Sensitivities of a distal polyp of ≥10 mm and of an advanced distal neoplasm for APN were both
38.8% with positive predictive values of 13.3 and 14.4%, respectively.
Conclusions Although distal colon findings were found to be helpful for predicting APN in asymptomatic patients aged ≥50 years, APN without
distal polyps requires careful consideration. 相似文献