The effect of three beta-lactamase inhibitors, clavulanic acid, sulbactam and tazobactam used in clinical practice were compared for their activity against purified beta-lactamases from Bacteroides uniformis, Clostridium butyricum and Fusobacterium nucleatum. The enzymes from B. uniformis and C. butyricum were produced in fermenters under controlled growth conditions and the enzyme from F. nucleatum was produced in batch cultures. Purification of the beta-lactamases was achieved by anion-exchange chromatography, gel filtration and FPLC-technique. The degree of inactivation of beta-lactamase activity was determined spectrophotometrically with nitrocefin as the substrate. The inhibitors in various concentrations were preincubated at 30 degrees C together with the enzyme for different time periods (0.5-120 min) before determination of the remaining beta-lactamase activity. The inhibitors all decreased the activity of the beta-lactamases investigated. Clavulanic acid and sulbactam were capable of reducing the enzyme activity of the B. uniformis beta-lactamase more effectively than the C. butyricum and F. nucleatum beta-lactamases. All beta-lactamases tested were more susceptible to tazobactam than to clavulanic acid and sulbactam. 相似文献
Prediction of hemorrhagic transformation (HT) in patients treated by intravenous recombinant tissue-type plasminogen activator (rt-PA) is a challenging issue in acute stroke management. HT may be correlated with severe hypoperfusion. Signal changes may be observed at susceptibility-weighted magnetic resonance imaging (MRI) within large perfusion defects. A signal drop within cerebral veins at T2*-weighted gradient-echo MRI may be expected in severe ischemia, and may indicate subsequent risk of HT. The authors prospectively searched for an abnormal visibility of transcerebral veins (AVV) within the ischemic area in patients with hemispheric ischemic stroke, before they were treated with intravenous rt-PA therapy. Any correlation between AVV and baseline clinical or MRI findings, or further HT, was noted. An AVV was present in 23 of 49 patients (obvious, n = 8; moderate, n = 15), and was supported by severe hemodynamic changes at baseline MRI. The AVV was correlated with the occurrence of parenchymal hematoma type 2 at computed tomography during the first week (r = 0.44, P = 0.002). Five of six type 2 parenchymal hematomas occurred in association with obvious AVV. At multiple regression analysis, two baseline MRI factors had an independent predictive value for HT risk during the first week: the AVV and the cerebral blood volume ratio (Nagelkerke R2 = 0.48). 相似文献
Examined the changing profiles of intelligence in males with fragile X syndrome as these individuals increased in chronological age. Using a psychometric instrument designed to measure styles of information processing, 21 males aged 4 to 27 years were examined cross-sectionally in sequential processing, simultaneous processing, and achievement. The age of the subject was associated with age-equivalent levels of both simultaneous processing and achievement, but fragile X males did not show higher levels of sequential processing with increasing chronological age. Compared to younger fragile X males, the older subjects were more delayed in sequential processing skills relative to their abilities in other areas. A smaller longitudinal study confirmed the presence of a plateau in sequential processing among those subjects tested two times after the age of 10 years. Implications are discussed for diagnosis, intervention, and the matching of subject groups in mental retardation research.This research was supported in part by the John Merck Fund, the Joseph P. Kennedy, Jr. Foundation, NIH grants RR00125 and HD03008, and NIMH grants MH18268 and MH30929. We thank Wendy Marans and Joel Bregman for their comments on an earlier draft of this paper. 相似文献
A sample of 46 schizophrenic patients (26 men and 20 women) from a night clinic (N subjects) with an average age of 21.7 years at the time of first manifestation of the illness and a sample of hospital inpatients (H subjects) matched for diagnosis, sex, and age were followed up from 1971/1973 to 1983. The average age of the patients in 1983 was 40 years. The course of the illness and the pattern of hospitalization were investigated by personally questioning each patient and by scrutinizing all the case history records and other relevant documents; for each clinical cycle of illness, consisting of an overt phase followed by a quiescent interval, a case control sheet was filled out. The duration of illness was 18 years for the N subjects and 15 years for the H subjects. Longitudinal analysis of these years of illness in both patient samples showed a marked decrease in the number and duration of overt phases and stays in hospital, but a progressive aggravation of residual symptomatology during quiescent intervals and a progressively decreasing ability to work and earn a living.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Adenomatoid tumors are regarded as uncommon neoplasms of the paratesticular tissues, probably of mesothelial origin. The majority of cases reported have involved the epididymis. We report our experience with 8 cases of testicular tumors and 11 of epididymal adenomatoid tumors during a 13-year period, and review the relevant literature. The incidence of adenomatoid tumors relative to all tumors in the testis was 6.9% (8 of 116), exceeding that of Leydig cell tumors, which were previously believed to be the most common benign testicular neoplasms. The adenomatoid tumors included 38% epididymal tumors (11 of 29). The clinical course of the tumors was benign, without recurrences. Local excision is regarded as the treatment of choice for epididymal and testicular adenomatoid tumors. 相似文献
Background: The attempts to explain the unpredictability of extent of spinal block provided by plain local anesthetic solutions have resulted in many clinical reports; however, causes of this uncertainty are as yet unknown. Recently, normal values of the human cerebrospinal fluid densities have been studied showing important interindividual variations, especially between females and males. The current study was designed to evaluate as primary endpoint the influence of cerebrospinal fluid density values on the extent of spinal block with plain bupivacaine. The ancillary endpoints were search of factors explaining the interindividual differences in cerebrospinal fluid density values reported and determination of the relation between upper extent and regression of spinal anesthesia.
Methods: Sixty-four consecutive patients undergoing peripheral orthopedic surgery with spinal block were enrolled. Spinal anesthesia was performed in the lateral decubitus position with the operated side upward. Two milliliters of cerebrospinal fluid was sampled before injection of 3 ml plain bupivacaine 0.5%. The patient was immediately turned supine and remained in the horizontal position until the end of the study. Maximal sensory block level and time to sensory regression to L4 were determined for each patient enrolled. Cerebrospinal fluid and bupivacaine densities as well as cerebrospinal proteins, glucose, sodium, and chloride concentrations were measured.
Results: A highly significant correlation between cerebrospinal fluid density and maximal sensory block level was found (P = 0.0004). However, this correlation was poorly predictive (R2 = 0.37). Cerebrospinal fluid density, proteins, and glucose concentrations were significantly higher in men than in women: 1.000567 +/- 0.000091 versus 1.000501 +/- 0.000109 g/ml (P = 0.014), 0.46 +/- 0.18 versus 0.32 +/- 0.13 g/l (P = 0.001), and 3.27 +/- 0.7 versus 2.93 +/- 0.5 mm (P = 0.023), respectively. A highly significant (P = 0.0004) and predictive (R2 = 0.73) inverse correlation was found between maximal upper sensory extent and sensory regression to L4. 相似文献
The effect of bile on the development of 1,2-dimethylhydrazine (DMH)-induced colon cancer was studied in male Wistar rats. Experimental operative models were created, in which in Group 1, the half intestinal tract, the ileum, and the right side of colon were released from bile. In Group 2, both sides of the colon contained bile. The sham operated animals formed Group 3. These techniques changed the concentration of bile acid in different parts of the colon, and the daily total fecal bile acid excretion as well. After DMH treatment, the relationship between these changes of bile acid level and the development of colon cancer was studied. Significantly more tumors than in the control group were found if the daily total bile acid level and the bile acid concentration in the left side of the colon were increased. Our findings show an unambiguous connection between the fecal bile acid level and the incidence of DMH-induced colon cancer. 相似文献