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41.
Effects of 1-week head-down tilt bed rest on bone formation and the calcium endocrine system. 总被引:6,自引:0,他引:6
S B Arnaud D J Sherrard N Maloney R T Whalen P Fung 《Aviation, space, and environmental medicine》1992,63(1):14-20
To understand the potential early responses of human bone and the calcium endocrine system to spaceflight, we studied 8 healthy men, aged 35-44 years before, during, and after bed rest in a -6 degrees head-down tilt model for microgravity. Based on a novel single-dose labeling schedule, average rates of bone formation in the iliac crest were reduced in 6, unchanged in 1, and increased in 1 following the bed rest period. The decrease was greatest for subjects whose daily walking miles were highest (r = -0.762, p less than 0.05, n = 7). Before a measurable increase in ionized serum calcium the sixth bed rest day, there was increased excretion of urinary calcium and sodium, evident the first 2 bed-rest days and parallel for the entire week (r = 0.92, p less than 0.001). Reduced excretion of phosphorus and 3', 5' cyclic adenosine monophosphate on the first and second bed rest days was followed by an increase in serum phosphorus by the sixth bed rest day. Depressed serum concentrations of parathyroid hormone and 1,25-dihydroxyvitamin D were manifest by the sixth and seventh bed rest days. The similarity of the response of bone and the calcium endocrine system of healthy men after only 7 days to results of longer term bed rest studies emphasizes the responsiveness of the adult human skeleton to biomechanical stimuli induced by changes in activity and/or position. 相似文献
42.
Prognostic implications of patterns of failure for gastrointestinal leiomyosarcomas. 总被引:16,自引:0,他引:16
One hundred ninety-one patients with gastrointestinal leiomyosarcomas were analyzed to determine the prevalence in patterns of failure and the factors predicting those at higher risk of relapse at specific sites. Of 100 assessable patients who died of disease, 89% were found to have peritoneal tumor, 78% had liver metastases, and 32% had extraabdominal metastases. Of 132 patients (69%) with initial complete resection of the primary tumor, only 10% (n = 13) remained free of disease as of the last follow-up. The median interval to recurrence was 18 months; 60% of all recurrences occurred within 2 years after surgery. Half of these patients (n = 61) had metastases (predominantly in the liver) as the initial recurrence. Factors significantly associated with improved survival after relapse were initial disease-free interval of 18 months or more, recurrences either isolated to the peritoneal cavity or within the liver, or complete resection of peritoneal recurrences or liver metastases. In contrast, those patients with recurrences at multiple sites or unresectable disease had significantly shorter survival times. The presence of extraabdominal metastases also heralded an equally poor outcome. In conclusion, a multimodality approach is necessary to improve outcome from this disease because the liver and peritoneal cavity represent predominant sites of failure. Complete resection of isolated peritoneal or hepatic metastases improves survival and should be attempted when feasible. 相似文献
43.
The incidence, timing, and management of biliary tract complications after orthotopic liver transplantation. 总被引:29,自引:1,他引:28 下载免费PDF全文
F Greif O L Bronsther D H Van Thiel A Casavilla S Iwatsuki A Tzakis S Todo J J Fung T E Starzl 《Annals of surgery》1994,219(1):40-45
OBJECTIVE: This study analyzed the incidence and timing of biliary tract complications after orthotopic liver transplantation (OLTx) in 1792 consecutive patients. These results were then compared with those of previously reported series. Finally, recommendations were made on appropriate management strategies. SUMMARY BACKGROUND DATA: Technical complications after OLTx have a significant impact on patient and graft survival. One of the principal technical advances has been the standardization of techniques for biliary reconstruction. Nonetheless, biliary complications still occur. A 1983 report from the University of Pittsburgh reported biliary complications in 19% of all transplants, and an update in 1987 reported biliary complications in 13.2% of transplants. METHODS: The medical records of all patients who underwent liver transplantation and were hospitalized between January 1, 1988 and July 31, 1991 were reviewed. The case material consisted of the medical records of 217 patients treated for 245 biliary complications. RESULTS: Primary biliary continuity was established by either choledochocholedochostomy over a T-tube (C-C, n = 129) or a Roux-en-Y choledochojejunostomy with an internal stent (C-RY, n = 85). The overall incidence for biliary complication in this large series was 11.5%. Strictures (n = 93) and bile leak (n = 58) were the most common complications (69.6%). Most biliary complications (n = 143, 66%) occurred within the first 3 months after surgery. In general, leaks occurred early, and strictures developed later. Bile leaks were equally frequent in both C-C and C-RY (27.1% and 25.9%, respectively); strictures were more common after a C-RY type of reconstruction (36.4% and 52.9%, respectively). Twenty-one patients died, an incidence of 9.6%. Fifteen of the 21 biliary-related deaths were among patients treated for rejection before the recognition of biliary tract pathologic findings. CONCLUSIONS: Progress has been made on improving the results of biliary reconstruction after OLTx. Nonetheless, patients continue to experience biliary complications after OLTx, and these complications cause considerable loss of grafts and life. If significant additional improvement in patient and graft survival are to be obtained, the technical performance of OLTx must continue to improve. 相似文献
44.
In vivo production of tumor necrosis factor for the treatment of mice bearing Ehrlich ascites tumor.
Tumor necrosis factor (TNF) was produced in mice bearing Ehrlich ascites tumor (EAT) by priming with zymosan and subsequently challenging with lipopolysaccharide. The optimal conditions for the in vivo production of TNF in treating EAT bearing mice were established. The endotoxin shock induced in mice during TNF production could be minimized by the combined administration of sulindac and mannoheptulose. The endogenous TNF produced could suppress proliferation of EAT cells as well as prolong the survival time of mice bearing small tumors. 相似文献
45.
A 45-year-old man with neurofibromatosis presented with recurrent seizures due to hypoglycaemia caused by an insulinoma. The attacks were abolished after the successful removal of the insulinoma. This probably represents another example of the association between neurofibromatosis and a tumour consisting of cells with amine-precursor-uptake and decarboxylation. 相似文献
46.
Background : Electrohydraulic lithotripsy (EHL) has been available for endoscopic treatment of urinary calculi since 1960, but the large probe size and concerns regarding safety had previously restricted its use to the treatment of bladder calculi. However, recent refinements have made it particularly suitable for the treatment of ureteric calculi. Methods : The authors report their initial experience using EHL in conjunction with mini-ureteroscopy in the treatment of 94 ureteric calculi in 89 patients. The size of the calculi ranged from 3 to 19 mm in diameter, with a mean of 8.2 mm. The mean operating time was 29 min, ranging from 10 to 120 min. Results : A complete fragmentation rate of 91.5% of the calculi was achieved. There were no major complications and a low incidence of minor complications: haematuria (2.2%), urinary tract infection (3.4%) and postoperative ureteric colic (2.2%). There were four cases of minor ureteric perforations (4.5%); all were successfully treated using conservative measures. Conclusions : It is concluded that EHL is a safe and effective method of treating ureteric calculi. 相似文献
47.
48.
Mechanisms of quinolone resistance in Escherichia coli: characterization of nfxB and cfxB, two mutant resistance loci decreasing norfloxacin accumulation. 总被引:29,自引:23,他引:6 下载免费PDF全文
D C Hooper J S Wolfson K S Souza E Y Ng G L McHugh M N Swartz 《Antimicrobial agents and chemotherapy》1989,33(3):283-290
49.
Chronic inflammatory bowel diseases in Singapore 总被引:2,自引:0,他引:2
H S Ng 《Singapore medical journal》1989,30(1):32-33
50.
Christian J Streck Paxton V Dickson Catherine Y C Ng Junfang Zhou John T Gray Amit C Nathwani Andrew M Davidoff 《Clinical cancer research》2005,11(16):6020-6029
PURPOSE: Type I IFNs (IFN-alpha/beta) have shown significant antitumor activity in preclinical models but limited efficacy and significant toxicity in clinical trials. We hypothesized that the antitumor activity of type I IFNs could be enhanced by chronic, low-dose systemic delivery and sought to test this in murine neuroblastoma models. EXPERIMENTAL DESIGN: Continuous liver-generated expression of human IFN-beta (hINF-beta) was achieved through a gene therapy-mediated approach using adeno-associated virus vectors encoding hIFN-beta (AAV hINF-beta). Orthotopic localized retroperitoneal and disseminated models of neuroblastoma were established using three different xenografts. Immunohistochemical analysis and ELISA were used to evaluate the antiangiogenic effect of therapy. RESULTS: The development of both localized orthotopic (retroperitoneal) and disseminated neuroblastoma was prevented in all mice expressing hINF-beta. Continued growth of established retroperitoneal tumors, treated with AAV hINF-beta as monotherapy, was significantly restricted, and survival for mice with established, disseminated disease was significantly prolonged following administration of AAV hINF-beta. Analysis of treated tumors revealed a significant antiangiogenic effect. Mean intratumoral vessel density was diminished and expression of the angiogenic factors vascular endothelial growth factor and basic fibroblast growth factor were both decreased. Finally, combination therapy in which AAV hIFN-beta was used together with low-dose cyclophosphamide resulted in regression of both established retroperitoneal and disseminated disease. CONCLUSIONS: AAV-mediated delivery of hIFN-beta when used as monotherapy was able to restrict neuroblastoma growth due in part to inhibition of angiogenesis. When used in combination with conventional chemotherapy, AAV hIFN-beta was able to effect complete tumor regression. 相似文献