Provider-reported illness and absence due to illness among children attending child-care homes and centers in San Diego, Calif

PURPOSE: To compare the incidence of provider-reported illness and absence due to illness among children attending small child-care homes, large child-care homes, and child care centers in a large metropolitan area. METHODS: From July 6, 1992, through January 28, 1994, we collected information from child-care providers on illness and absence due to illness at 64 small and 58 large child-care homes and 41 child-care centers. This included 113 446 child-weeks of information on 5360 children. RESULTS: Providers reported 14 474 illness episodes (6.6 episodes per child-year) and 8593 days of absence due to illness (3.9 days per child-year). The incidence of illness episodes was greatest in children who were younger than 1 year, white, or enrolled in small child-care homes. The incidence of absence due to illness was greatest in children who were 1 year of age, Hispanic, or enrolled in child-care centers. Respiratory symptoms were most commonly associated with illness episodes and absence due to illness. CONCLUSIONS: Children in child-care homes had a greater incidence of provider-reported illness than did those in centers. This risk varied by the type of facility and was greatest in small child-care homes. The increased risk for absence due to illness among children in child-care centers reflects exclusion and attendance patterns. It may be possible to reduce the incidence of absence due to illness and subsequent economic impact of child-care-associated illness by educating providers on exclusion guidelines.     

A sequence-specific polymerase chain reaction assay for mitochondrial DNA polymorphisms in human platelets and white cells

BACKGROUND: Because mitochondria are abundant in white cells and are also present in platelets, polymorphic sequences in mitochondrial DNA (mtDNA) represent a unique target for polymerase chain reaction (PCR)- based detection of donor material. STUDY DESIGN AND METHODS: A PCR assay was developed that uses sequence-specific primers (SSP) focused on two continent-specific mtDNA polymorphisms. Results were validated by the use of informative restriction endonucleases. Three commercially available methods to extract mtDNA from white cell-reduced human platelets was compared. In preparation for in vivo studies, in vitro mixing studies designed to mimic transfusion were conducted to investigate the performance of the SSP-PCR assay. RESULTS: The gene sequences of two representative examples of amplicons obtained with the new SSP-PCR matched the sequence expected from the published genetic code. Fifteen individuals were classified as either positive (n = 6) or negative (n = 9) for the Asian polymorphism by the use of published primers known to flank the polymorphic site followed by digestion with appropriate restriction enzymes. Results with SSP-PCR were nearly perfectly concordant with those of restriction enzyme analysis. Although the use of three DNA extraction methods allowed the preparation of mtDNA that was suitable for PCR, large and consistent differences (ranging from 10- to 1000-fold) in endpoint sensitivity were found. In vitro mixing studies reproducibly documented that the SSP-PCR assay could detect as little as 1 percent of donor platelets mixed with recipient blood. CONCLUSION: PCR-SSP can be reliably used to identify human mtDNA polymorphisms. By optimization of the method of mtDNA extraction, the sensitivity of PCR-SSP assay was greatly increased. This assay should prove useful in investigations of allogeneic platelet transfusions without cell labeling. It may also be applied to studies of the donor cell microchimerism that follows transfusion or transplantation.     

Computer graphics for digitally formatted images

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.     

多波长数据线性双组合同步荧光法测定苯酚与间苯二酚

提出了多波长数据线性双组合法计算解析苯酚和间苯二酚混合物的同步荧光光谱,考察了△λ=λ_em-λ_ex,pH,光路中光照时间对二种酚的荧光强度影响,建立了同时测定混合物中苯酚和间苯二酚的新方法。用于复方雷琐辛涂剂中苯酚与间苯二酚的同时测定,平均回收率分别为:苯酚98.5%±1.4%;间苯二酚98.8%±1.3%。     

金刚大化学成分的研究

从百部科黄精叶钩吻属植物金刚大(Croomia japonica Miq)的根部分得五个成分,分别为粉蕊黄杨胺A(pachysamine A,Ⅰ)、金刚大啶(croomionidine,Ⅱ)、金刚大碱(croomme,Ⅲ)、脱氢金刚大碱(didehydrocroomine,Ⅳ)和β-谷甾醇。应用波谱(IP,MS,¹HNMR和¹³CNMR等)分析、理化数据测定和化学转化,确定丁它们的结构,其中金刚大啶为新甾体生物碱。     

麦冬多糖对正常和实验性糖尿病小鼠血糖的影响

目的：研究麦冬多糖对正常和实验性糖尿病小鼠血糖的影响。方法：昆明种小鼠４０只，分成４组，分别用麦冬多糖（１００和３００ｍｇ／ｋｇ）、优降糖（２．５ｍｇ／ｋｇ）和等体积生理盐水（２ｍｌ／只）灌胃，测定各组正常小鼠的血糖水平及以葡萄糖（２ｇ／ｋｇ）、四氧嘧啶（７０ｍｇ／ｋｇ）、肾上腺素（０．０２ｍｇ／ｋｇ）所致小鼠高血糖模型的血糖水平。结果：剂量为１００和３００ｍｇ／ｋｇ的麦冬多糖灌胃对葡萄糖、四嘧啶