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排序方式: 共有10000条查询结果,搜索用时 171 毫秒
901.
D.L. Morgan J.R. Bucher M.R. Elwell H.S. Lilja A.S. Krishna Murthy 《Food and chemical toxicology》1990,28(12):839-845
Studies were conducted to compare the toxicity of ethylene dichloride (EDC) in F344/N rats, Sprague-Dawley rats, and Osborne-Mendel rats. Ten rats/sex/group were exposed to EDC in drinking-water at 0, 500, 1000, 2000, 4000 and 8000 ppm for 13 wk. The highest concentration was limited by the maximum solubility of EDC in water (about 9000 ppm). In addition, F344/N rats (10/sex/group) were administered EDC in corn oil by gavage to compare toxicity resulting from bolus administration with that of continuous exposure in drinking-water. Gavage doses of EDC were within the range of total daily doses (in mg/kg body weight/day) resulting from exposure in drinking-water. EDC administered by gavage resulted in greater toxicity to F344/N rats than did administration of similar doses in drinking-water. All males receiving 240 and 480 mg/kg body weight and 9/10 females receiving 300 mg/kg body weight by gavage died before the end of the study. Necrosis of the cerebellum was observed in the brains of 3 males receiving 240 mg/kg body weight and 3 females receiving 300 mg/kg body weight. Hyperplasia and inflammation of the forestomach mucosa were observed in 8 male and 3 female rats that died or were killed in moribund condition. EDC caused minimal toxicity to F344/N, Sprague-Dawley and Osborne-Mendel rats at the drinking-water concentrations used in these studies; only female F344/N rats had EDC-related renal lesions. Based on mortality and EDC-related lesions, the no-effect levels for EDC administered by gavage to F344/N rats were 120 mg/kg body weight for males and 150 mg/kg body weight for females. 相似文献
902.
903.
Measurements were made of glutathione (GSH) levels, catalase activity and the oxidant sensitivity of the erythrocytes from
the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula). The oxidant sensitivity was tested by treating the haemolysates with either 0.55 him H2O2 or 1.4mm NaNO2. The erythrocytes of the koala had greater levels of GSH and catalase and yet were found to be more susceptible to oxidation
induced by both these oxidants. 相似文献
904.
T. Akatsu T. Murakami K. Ono M. Nishikawa E. Tsuda S.-I. Mochizuki N. Fujise K. Higashio K. Motoyoshi M. Yamamoto N. Nagata 《BONE》1998,23(6):495-498
Osteoclastogenesis inhibitory factor (OCIF) is a novel secreted protein that inhibits osteoclastogenesis both in vitro and in vivo. In this study, we examined the effects of OCIF on serum calcium (Ca) concentrations in normal mice and in hypercalcemic nude mice carrying tumors associated with humoral hypercalcemia of malignancy. In normal mice, a single intraperitoneal injection of OCIF reduced serum Ca levels in a dose-dependent manner. Significant decrease in serum Ca (by 1.6 ± 0.3 mg/dL, n = 5) was observed 2 h after the injection of OCIF at 20 mg/kg and the hypocalcemic effect continued for up to 12 h. Serum phosphate (Pi) concentrations also decreased in response to OCIF. Urinary excretion of Ca, Pi, and creatinine did not change significantly after injection of OCIF or vehicle. In hypercalcemic, tumor-bearing nude mice, a single intraperitoneal injection of OCIF at 20 mg/kg resulted in a dramatic decrease in serum Ca (maximal decrease 2.8 ± 0.37 mg/dL, n = 11), which continued for up to 24 h. The results suggest that OCIF decreased serum Ca through its inhibitory effect on bone resorption. Furthermore, it is suggested that OCIF has therapeutic potential for the treatment of hypercalcemic conditions such as malignancy-associated hypercalcemia. 相似文献
905.
Duration of protective immunity conferred by maternal tetanus toxoid immunization: further evidence from Matlab, Bangladesh. 总被引:3,自引:2,他引:1 下载免费PDF全文
M A Koenig N C Roy T McElrath M Shahidullah B Wojtyniak 《American journal of public health》1998,88(6):903-907
OBJECTIVES: Although maternal tetanus immunization has been shown to be highly effective in the prevention of neonatal tetanus, unresolved questions remain concerning the required minimum number of doses and the resulting duration of effective immunity. This study examined the duration of effective immunity against neonatal tetanus provided by maternal tetanus immunization. METHODS: A randomized, double-blind cholera vaccine trial of 41,571 children and nonpregnant adult women carried out in 1974 in the Matlab comparison area of rural Bangladesh provided a unique opportunity to address dose and immunity issues. RESULTS: Children of women who received either 1 or 2 injections of tetanus toxoid experienced 4- to 14-day mortality levels consistently lower than those of children of unimmunized mothers. Analysis of neonatal-tetanus-related mortality showed that 2 injections of tetanus toxoid provided significant protection for subsequent durations of up to 12 or 13 years. CONCLUSIONS: The data demonstrate that a limited-dose regimen of maternal tetanus toxoid provides significant and extended protection against the risk of neonatal tetanus death. 相似文献
906.
C Niek van Dijk Ben Willem J. Mol Liesbeth S. L. Lim Rene K. Marti Patrick M. M. Bossuyt 《Acta orthopaedica》1996,67(6):566-570
We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on. 122 of these patients had ligament ruptures.
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
907.
A clinical trial on the prevention of catheter-related sepsis using a new hub model. 总被引:8,自引:0,他引:8 下载免费PDF全文
M Segura F Alvarez-Lerma J M Tellado J Jiménez-Ferreres L Oms J Rello T Baró R Sánchez A Morera D Mariscal J Marrugat A Sitges-Serra 《Annals of surgery》1996,223(4):363-369
BACKGROUND: Catheter hub contamination is being increasingly recognized as a source of catheter-related sepsis. The authors have investigated the efficacy of a new hub design in preventing endoluminal catheter contamination and catheter-related sepsis arising at the hub. METHODS: Adult surgical and intensive care patients requiring a subclavian catheter for at least 1 week were randomly assigned to receive catheters with standard connectors (control group, n=73) or equipped with a new hub model (new hub group, n=78). Skin, catheter tip, and hub cultures were performed at the time the catheter was withdrawn because therapy was terminated or because of suspicion of sepsis, in which case peripheral blood cultures were taken. RESULTS: Of the 151 patients included, 15 (10%) developed catheter-related sepsis. Catheters were more often withdrawn because suspicion of infection in the control group (42 vs. 19%, p<0.005). Catheter sepsis rate was higher in the control group (16 vs. 4%, p<0.01) because of the low rate of catheter sepsis arising at the hub observed in the new hub group (1 vs. 11%, p<0.01). The prevalence of culture-positive catheter hubs without associated bacteremia (colonization) was higher in the control group (18 vs. 5%, P<0.03). CONCLUSIONS: A new catheter hub has proved to be useful in preventing endoluminal bacterial colonization and catheter-related sepsis in subclavian lines inserted for a mean of 2 weeks. 相似文献
908.
909.
910.
Ch. Lenzen N. Roewer F. Wappler A. Köchling M. Steinfath J. Sgholz J. Schulte am Esch 《Acta anaesthesiologica Scandinavica》1995,39(3):343-346
Dantrolene seems to be the causal therapy in malignant hyperthermia (MH) crisis but the complex mechanisms of MH and dantrolene therapy are still not fully understood. The influence of dantrolene on ryanodine-induced contractures has been reported in animal studies only. In the present study 20 patients from] 7 families were tested for MH using the protocol of the European Malignant Hyperthermia Group. In addition ryanodine-induced contractures were evaluated following bolus application of 10.0 μmol · 1-1 ryanodine. After pretreatment with 1 μimol · 1-1 dantrolene ryanodine-provoked contractures developed significantly later in MHS (15.8±1.8 min) and MHN (46.0±4.2 min) muscle specimens than after ryanodine alone (MHS 4.8±0.7 min), (MHN 13.7±0.9 min). They were no longer observed in either group after pretreatment with 5 μimol · 1-1 dantrolene. We conclude that dantrolene is able to attenuate ryanodine-induced contractures dose-dependendy, and therefore it is speculated that dantrolene could specifically act at the ryanodine receptor binding site. 相似文献