Deficits in the processing of local and global motion in very low birthweight children

This study evaluated the impact of premature birth on the development of local and global motion processing in a group of very low birthweight (<1500 g), 5- to 8-year-old children. Sensitivity to first- and second-order local motion stimuli and coherence thresholds for global motion in random dot kinematograms were measured. Relative to full-term controls, premature children showed deficits on all three aspects of motion processing. These problems could not be accounted for by stereo deficits, amblyopia, or attentional problems. A history of mild retinopathy of prematurity and/or intraventricular hemorrhage increased risk, but deficits were observed in some children with no apparent ocular or cerebral pathology. It is important to note that, despite the observed group differences, individual profiles of performance did vary; the results suggest that these three forms of motion processing may involve separate neural mechanisms. These findings serve to increase our understanding of the organization and functional development of motion-processing subsystems in humans, and of the impact of prematurity and associated complications on visual development.     

甘氨双唑钠对鼻咽癌放射增敏作用的临床观察

[目的]研究甘氨双唑钠（CMNa）对鼻咽癌放射治疗的增敏作用以及毒副反应。[方法]将46例经病理学确诊的初治鼻咽癌患者分为放射增敏组（A组,放疗加用甘氨双唑钠）和对照组（B组,单纯放疗）。两组放射治疗方法完全相同,整体挡铅法体外常规放射治疗,鼻咽部DT（68～76）Gy/（34～36）次,6～7周,颈转移淋巴结DT（68～72）Gy/（34～36）次,6～7周,颈部预防量DT56Gy/28次,5～6周。A组在放疗前1h静脉滴注CMNa800mg/m2,每周3次,至放疗结束,B组行单纯常规放疗。[结果]放射增敏组和单纯放疗组放疗结束鼻咽癌原发灶CR率分别为87.5%、59.1%（P=0.028）;颈淋巴结转移灶CR率分别为79.1%、45.5%（P=0.018）,放疗后2～3个月,颈淋巴结转移灶CR率分别为87.5%、45.5%（P=0.002）。鼻咽癌原发灶和颈淋巴结转移灶达部分缓解时放射增敏比（SER）分别为1.49和1.40,达完全缓解时SER分别为1.21和1.18。两组患者放疗毒副反应比较差异无统计学意义。[结论]CMNa能提高鼻咽癌放射治疗完全缓解率,降低达缓解时所需剂量,且不增加放疗毒副反应。     

Tubal sterilization in the United States, 1994-1996

CONTEXT: Although the number and rate of tubal sterilizations, the settings in which they are performed and the characteristics of women obtaining sterilization procedures provide important information on contraceptive practice and trends in the United States, such data have not been collected and tabulated for manyyears. METHODS: Information on tubal sterilizations from the National Hospital Discharge Survey and the National Survey of Ambulatory Surgery was analyzed to estimate the number and characteristics of women having a tubal sterilization procedure in the United States during the period 1994-1996 and the resulting rates of tubal sterilization. These results were compared with those of previous studies to examine trends in clinical setting, in the timing of the procedure and in patient characteristics. RESULTS: In 1994-1996, more than two million tubal sterilizations were performed, for an average annual rate of 1 1.5 per 1,000 women; half were performed postpartum and half were interval procedures (i. e., were unrelated by timing to a pregnancy). All postpartum procedures were performed during inpatient hospital stays, while 96% of interval procedures were outpatient procedures. Postpartum sterilization rates were higher than interval sterilization rates among women 20-29 years of age; interval sterilization procedures were more common than postpartum procedures at ages 35-49. Sterilization rates were highest in the South. For postpartum procedures, private insurance was the expectedprimary source of payment for 48% and Medicaid was expected to pay for 41 %; for interval sterilization procedures, private insurance was the expected primary source of payment for 68% and Medicaid for 24%. CONCLUSIONS: Outpatient tubal sterilizations andprocedures using laparoscopy have increased substantially since the last comprehensive analysis of tubal sterilization in 1987, an indication of the effect of technical advances on the provision of this service. Continued surveillance of both inpatient and outpatient procedures is necessary to monitor the role of tubal sterilization in contraceptive practice.     

绞股蓝皂甙与银杏内脂黄酮对HL-60细胞增殖的影响

目的:探讨并比较绞股蓝皂甙(Gypenosides,GP)与银杏内脂黄酮影响急性髓性白血病(HL-60)细胞增殖的作用.方法:分别以不同浓度绞股蓝皂甙与银杏内脂黄酮,不同作用时间处理HL-60细胞株,用MTT法观察绞股蓝皂甙与银杏内脂黄酮对(HL-60)细胞增殖的影响,流式细胞仪检测细胞增殖周期情况.结果:绞股蓝皂甙与银杏内脂黄酮在0.025～0.8 mg/ml终浓度范围内,对HL-60细胞增殖的抑制作用显著,并随药物浓度及作用时间的增加而增强(P＜0.05).两药均可显著减少G2/M 期细胞,增加G0/G1期细胞,并诱导凋亡细胞峰出现.结论:绞股蓝皂甙与银杏内脂黄酮均能显著的影响HL-60细胞增殖,两种药物抑制HL-60细胞增殖的机制与干扰细胞增殖、分裂,诱导凋亡有关.     

Megestrol acetate treatment of growth failure in children infected with human immunodeficiency virus

OBJECTIVE: To evaluate the effect of megestrol acetate on weight gain and linear growth in human immunodeficiency virus-infected children with growth failure. METHODS: All human immunodeficiency virus-infected children with growth failure treated with megestrol acetate at our institution were evaluated retrospectively. Weight, height, and weight:height ratio were documented from 6 months before initiation of megestrol acetate until 6 months after treatment was discontinued. Measurements were corrected for age and sex by conversion to z-scores. Incremental growth was determined before, during, and after treatment. The potential effects of CD4+ T-lymphocyte count and percentage, antiretroviral therapy, and intercurrent illnesses on growth were evaluated. RESULTS: Nineteen patients were treated with a total of 27 courses of megestrol acetate. The median duration of therapy was 7 months (range, 3 to 11 months), and the median megestrol acetate dose was 7.91 mg/kg/day (range, 4.06 to 8.56 mg/kg/day). From 6 months and 3 months before treatment to the onset of therapy, median changes in weight z-scores were -.27 and -.15, respectively. During megestrol acetate treatment, median changes in weight z-scores were +.29 after 1 month of therapy, +.40 after 3 months, and +.57 after 6 months. After megestrol acetate therapy was discontinued, poor weight gain and weight loss resumed. Median 6-month growth velocities for weight were less than the 10th percentile before megestrol acetate, greater than the 97th percentile during treatment, and less than the 3rd percentile after treatment was discontinued. Megestrol acetate therapy was not associated with changes in linear growth. Antiretroviral therapy, CD4+ T-lymphocyte count or percentage, or intercurrent illnesses were not associated with statistically significant differences in response to megestrol acetate therapy. CONCLUSIONS: Megestrol acetate treatment of growth failure in pediatric human immunodeficiency virus disease is associated with weight gain, without affecting linear growth.     

Discovering co-learning with students in distance education sites

Distance education is promoted as an effective way to reach more students, but how effective are interactive learning strategies in distance nursing courses? The authors discuss how nursing students adjusted to distance technologies and became actively involved in creating an environment that enabled development of supportive co-learning relationships. Learner perspectives on teaching strategies, distance learning, and becoming nurses are described.     

Whole-genome linkage analysis of rheumatoid arthritis susceptibility loci in 252 affected sibling pairs in the United Kingdom

OBJECTIVE: To undertake a systematic whole-genome screen to identify regions exhibiting genetic linkage to rheumatoid arthritis (RA). METHODS: Two hundred fifty-two RA-affected sibling pairs from 182 UK families were genotyped using 365 highly informative microsatellite markers. Microsatellite genotyping was performed using fluorescent polymerase chain reaction primers and semiautomated DNA sequencing technology. Linkage analysis was undertaken using MAPMAKER/SIBS for single-point and multipoint analysis. RESULTS: Significant linkage (maximum logarithm of odds score 4.7 [P = 0.000003] at marker D6S276, 1 cM from HLA-DRB1) was identified around the major histocompatibility complex (MHC) region on chromosome 6. Suggestive linkage (P < 7.4 x 10(-4)) was identified on chromosome 6q by single- and multipoint analysis. Ten other sites of nominal linkage (P < 0.05) were identified on chromosomes 3p, 4q, 7p, 2 regions of 10q, 2 regions of 14q, 16p, 21q, and Xq by single-point analysis and on 3 sites (1q, 14q, and 14q) by multipoint analysis. CONCLUSION: Linkage to the MHC region was confirmed. Eleven non-HLA regions demonstrated evidence of suggestive or nominal linkage, but none reached the genome-wide threshold for significant linkage (P = 2.2 x 10(-5)). Results of previous genome screens have suggested that 6 of these regions may be involved in RA susceptibility.