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991.
In this study, baseline plasma from 619 persons with acquired immunodeficiency syndrome (AIDS) (median CD4+ lymphocyte count -21/microl) who participated in a trial to determine the efficacy of oral ganciclovir for cytomegalovirus (CMV) disease prevention were evaluated for CMV DNA load by qualitative and quantitative polymerase chain reaction (PCR), and correlated with the development of CMV disease and survival. For participants without detectable plasma CMV DNA, the 12-mo Kaplan-Meier CMV disease event rate was 14% and 1% for the placebo and ganciclovir groups, respectively (P < 0.001). For PCR positive participants, CMV disease developed in 43% of placebo and 26% ganciclovir recipients (P < 0.017). Among placebo recipients, CMV PCR positivity was associated with a 3.4-fold increased risk of developing CMV disease (P < 0.001) whereas CD4+ lymphocyte count was not a useful predictor (P = 0.47). A positive plasma CMV DNA PCR was also associated with a 2.5-fold increased risk of death. Each log10 increase in baseline CMV DNA load was associated with a 3.1-fold increase in CMV disease (P < 0.001) and a 2.2-fold increase in mortality (P < 0.001). These data indicate that the risk of developing CMV disease and death in persons with advanced AIDS is directly related to the quantity of CMV DNA in plasma, and is a better predictor than CD4+ lymphocyte count in this population.  相似文献   
992.
In a double-blind study, 655 sputum specimens were obtained from individuals suspected of having tuberculosis and were analyzed for the presence of Mycobacterium tuberculosis and rifampin susceptibility with use of a polymerase chain reaction (PCR)-based universal heteroduplex generator assay (PCR/UHG-Rif). Of the specimens containing viable M. tuberculosis, 100% of the smear-positive (n = 41) and 50% of the smear-negative (n = 6) specimens tested positive for the organism by PCR/UHG-Rif. Nineteen of 537 culture-negative specimens tested positive for M. tuberculosis by PCR/UHG-Rif and were from patients with confirmed tuberculosis who were receiving antituberculosis therapy at the time of specimen collection. Thirty-five specimens contained nontuberculous mycobacteria and were negative by PCR/UHG-Rif. Genotypic evidence of rifampin resistance in five of six culture-confirmed, rifampin-resistant isolates was obtained by PCR/UHG-Rif, yielding a sensitivity and specificity for the assay of 83% and 98.2%, respectively. These results demonstrate the feasibility of using a PCR-based assay directly on sputum specimens for simultaneous detection of M. tuberculosis and rifampin susceptibility, and they suggest that patients with smear-positive, untreated tuberculosis and those presenting with suspected drug-resistant tuberculosis are the most appropriate groups for testing by PCR/UHG-Rif.  相似文献   
993.
OBJECTIVE: Our purpose was to characterize the findings associated with dextroposition of the fetal heart. STUDY DESIGN: A fetal echocardiography database was retrospectively searched from January 1990 through December 1996 to identify all cases referred or diagnosed with dextroposition of the fetal heart. Dextroposition was defined as most of the normally connected fetal heart found on the right side of the fetal chest. Intracardiac and extracardiac fetal anomalies were reviewed. All available karyotypes and postnatal examinations were reviewed. RESULTS: During the study period 2882 fetal echocardiograms were performed, of which 297 (10.3%) were abnormal. Of these, 14 had dextroposition. Associated anomalies included atrioventricular canal (29%), diaphragmatic hernia (21%), and aneuploidy (14%). Isolated dextroposition with no other significant anomalies was seen in only 1 case. In another, no anomalies were noted except for suspected agenesis of 1 lobe of the right lung; karyotype and postnatal evaluation revealed no other abnormalities in both cases. CONCLUSIONS: Dextroposition of the fetal heart was seen in 0.5% of our fetal echocardiograms and was associated with significant anomalies in 86% of our cases. When diagnosed, a targeted ultrasonogram, fetal echocardiogram, and karyotype should be offered.  相似文献   
994.
BACKGROUND: Neuroblastoma is the most common extracranial solid tumor among pediatric patients, and orbital metastatic disease is not uncommon in these children. Physical signs as a consequence of orbital metastases, such as proptosis and periorbital ecchymosis, frequently are encountered. However, subsequent blindness is rare. METHODS: A retrospective study was conducted to determine the incidence, related physical findings, treatment, and outcome of children who developed visual loss during treatment for neuroblastoma. Medical records for a 24-year period (1971-1994) were reviewed to identify these patients. The charts, diagnostic imaging studies, and autopsy material of these patients were reviewed. RESULTS: Of the 450 patients treated for neuroblastoma at the study institution during this period, 47 presented with abnormalities in physical examination of the eye. Eight of these 47 patients and 7 others developed visual loss in at least 1 eye during the first week after diagnosis (n = 5), during primary therapy (n = 6), at recurrence (n 2), or after completion of therapy (n = 2). In ten patients the visual loss was a direct consequence of the primary disease process, whereas a direct relationship between loss of vision and neuroblastoma could not be identified in the remaining five patients. Proptosis and periorbital ecchymosis were the most common associated physical findings. Although ten patients received steroids and eight received radiation, visual loss could not be prevented or reversed in these patients. CONCLUSIONS: Early initiation of effective, multiagent chemotherapy remains the primary approach for the treatment of neuroblastoma and its ophthalmologic complications. Radiation therapy and steroids may have benefit but failed to show good effect in this series. The prevention and treatment of blindness is probably most relevant in infants and children age < 2 years because they have the best chance for cure.  相似文献   
995.
Adsorption onto the dialyzer membrane is a contributing factor to the elimination of beta2-microglobulin (beta2M) from the sera of uremic patients. The purpose of this prospective study was to ascertain the influence of the blood flow rate on adsorption of beta2M onto the polyacrylonitrile (AN69) hollow-fiber dialyzer membrane in 8 patients during regular hemodialysis (HD). Blood first passed through a low-flux polysulfone dialyzer and then through an AN69 dialyzer, which was not in contact with the dialysis fluid. During the investigation period (first hour of the HD session), the blood flow rate was 100 ml/ min (first part of the study), 200 ml/min (second part of the study), and 300 ml/min (third part of the study). Ultrafiltration was not performed during the investigation period. At the start of the HD sessions, the serum concentration of beta2M in the afferent blood line did not differ significantly among the 3 parts of the study. Serum beta2M was measured in samples taken from the afferent and efferent blood lines of the AN69 dialyzer at 5, 10, 15, 30, 45, and 60 min. The serum beta2M concentration decreased significantly in blood that had passed through the AN69 dialyzer. This decrease, indicating membrane adsorption, was maximal during the first part and minimal during the third part of study. The decrease in the contact time between the blood and the AN69 could be the underlying cause. The calculated quantities of beta2M adsorbed onto the AN69 membrane (44.2 +/- 10.2, 43.2 +/- 12.1, and 42.6 +/- 17.3 mg) did not differ significantly among the 3 parts of the study. These results suggest that an increase in blood flow rate from 100 to 300 ml/min did not significantly affect the quantity of beta2M adsorbed onto the AN69 membrane.  相似文献   
996.
The influence of various adjuvants on the development of influenza virus neutralizing antibodies and distribution of anti-influenza virus IgG isotypes after immunization of mice with influenza A (H3N2) subunit vaccine was investigated. Serum titres of influenza virus neutralizing antibodies and titres of influenza specific IgG isotypes were determined by a neutralization enzyme immunoassay (N-EIA) and a cell-associated antigen enzyme immunoassay (CA-EIA), respectively. Serum antibody titres as measured by the two tests correlated highly (r = 0.82; P < 0.001). N-EIA titres were enhanced by 38- and 34-fold, when L180.5/RaLPS and FCA, respectively, were administered with 1 microgram of vaccine. The adjuvants Q-VAC, L180.5 [W/O/W], L180.5 alone and Montanide ISA 740 were only moderately or not effective in enhancing the immune response to the 1 microgram dose of vaccine. The Q-VAC and L180.5/RaLPS adjuvants favoured IgG2a and IgG2b isotype responses to influenza compared to the other adjuvants. We suggest that N-EIA and CA-EIA may be valuable tools to monitor the effects of adjuvants on the neutralizing antibody and antibody isotype responses after influenza vaccination.  相似文献   
997.
998.
Sphingosine, which is on the pathway of sphingomyelin degradation, activates phospholipase C (PLC) delta1 moderately. In the liposome assay effect of sphingosine on PLC delta1 activity depends on KCl concentration. Stimulation of PLC delta1 by sphingosine increased as the KCl concentration is increased from 0 to 100 mM, and then diminished with the increasing KCl. In the liposome assay sphingosine diminishes inhibition of PLC delta1 by sphingomyelin. To determine the domain of PLC delta1 which interacts with sphingosine active proteolytic fragments of PLC delta1 were generated by trypsin digestion of the native enzyme. Sphingosine affects the activity of PLC delta1 fragment which lacked the amino-terminal domain (first 60 amino acids) but not the active fragment that has cleaved the domain spanning the X and Y region of PLC delta1. These observations indicate that for interaction of sphingosine with PLC delta1 intact domain that span regions of conservation, designated as X and Y is necessary. When the activity of PLC delta1 was assayed with PIP2 in the erythrocyte membrane as substrate, sphingosine strongly inhibited PLC delta1. The other homolog of sphingosine 4-hydroxysphinganine (phytosphingosine) inhibited PLC delta1 to much lesser extent. The activity of PLC delta1 was inhibited by 68% and 22% in the presence of 20 microM sphingosine and phytosphingosine, respectively. This inhibition was completely abolished by deoxycholate at a concentration of 1.5 mM. These observations suggest that sphingosine may regulate activity of PLC delta1 in the cell.  相似文献   
999.
Group A human rotavirus G serotypes were detected in stool specimens from neonates and infants with and without acute diarrhea in Cairo by using monoclonal antibodies in an enzyme-linked immunosorbent assay. Serotypes G1 and G4 predominated in all age groups. Mixed (G1 plus G4) and nontypeable specimens represented 16.1 and 38.7% of the total number serotyped, respectively.  相似文献   
1000.
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