Platelet proteins as autoantibody targets in idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP), caused by autoantibodies directed against certain platelet antigens, is the most common entity of the immune thrombocytopenias. ITP is an acquired disorder and can affect both children and adults. However, the clinical syndromes of ITP are distinct between children and adults. Childhood (acute) ITP characteristically is acute in onset, occurs within 1-2 weeks of an infection, usually of viral origin, resolves spontaneously within 6 months. Adult (chronic) ITP has an insidious onset and rarely resolves spontaneously. Over the last decade considerable new information has accumulated as to the pathophysiological mechanisms of immune thrombocytopenias. In addition, most of the knowledge on this disorder has been obtained from studies of adult patients with chronic ITP. The present work gives an updated overview of the platelet autoantigens and the molecular immunological reactions in ITP.     

Unusual features in children with inv dup(15) supernumerary marker: a study of genotype-phenotype correlation in Taiwan

Recent molecular cytogenetic studies have elucidated the origin and nature of extra structurally abnormal chromosomes (ESACs) or small supernumerary chromosomes, which are often associated with developmental delay and malformations. We studied the prevalence of inv dup(15) in a nationwide screening programme for mentally retarded children in Taiwan and tried to correlate the genotype and phenotype in those patients. Fluorescence in situ hybridization (FISH) analysis using D15Z, D15Z1, and the cosmids from the Prader-Willi/Angelman syndrome chromosome region (PW/ASCR) was performed on 54 patients (0.45%) with ESACs from 11893 probands within a 5-year period. Of them, inv dup(15) was confirmed in 25 children (46.3%) by FISH analysis. The PW/ASCR probes were used to clarify the size and DNA composition of the markers. Patients with inv dup(15) chromosomes, containing only the heterochromatin or little euchromatin of the proximal 15q (i.e., pter→q11:q11→pter) may have a rather mild or nearly normal phenotype (group 1). Only one patient had some features suggestive of Angelman syndrome, but was considered to be a result of deleted (15)(q12) in the chromosome 15 homologue. Additional copies within D15S11 through GABRB3 (15q11.2-13) resulted in an abnormal phenotype which involved mental and developmental delay but was different from the classical phenotype of PW/AS (groups 2, 3). Signs of autistic behavior did occur in each group. FISH combined with microsatellite analyses showed that the marker was often of maternal origin in de novo cases (n = 12, 86%), or inherited from the mother in only one familial case. Down-inv dup(15) was mentioned in two cases. Unusual features including diaphragmatic eventration, hyperlaxity of joints, arachnodactyly, brain atrophy, epilepsy (particularly infantile spasm), ataxia, genital abnormalities, and cleft lip/palate were noted in those patients. This observation expands the range of phenotypic expression associated with this relatively common ESAC. Conclusion Marked phenotypic diversities exist in children with inv dup(15), dependent upon the size or genetic composition of the markers, degree of mosaicism, parental origin and familial occurrence or not. Patients with a larger inv dup(15) marker chromosome including the PW/ASCR may have a higher risk of abnormalities, but not the typical Prade-Willi/Angelman syndrome phenotype. Received: 11 February 1997 and in revised form: 20 May 1997 / Accepted: 20 May 1997     

Spectrum of point mutations in the coding region of the hypoxanthine- guanine phosphoribosyltransferase (hprt) gene in human T-lymphocytes in vivo

The hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in 6- thioguanine (TG) resistant T-lymphocytes is a useful target for the study of somatic in vivo mutagenesis, since it provides information about a broad spectrum of mutation. Mutations in the hprt coding region were studied in 124 TG-resistant T-cell clones from 38 healthy, non- smoking male donors from a previously studied population of bus maintenance workers, fine-mechanics and laboratory personnel. Their mean age was 43 years (range 23-64) and their hprt mutant frequency was 9.3 +/- 5.2 x 10(-6) (mean +/- SD, range 1.4-22.6 x 10(-6)). Sequence analysis of hprt cDNA identified 115 unique mutations; 76% were simple base substitutions, 10% were +/-1 bp frameshifts, and 10% were small deletions within exons (3-52 bp). In addition, two tandem base substitutions and one complex mutation were observed. Simple base substitutions were observed at 55 (20%) of 281 sites known to be mutable in the hprt coding sequence. The distribution of these mutations was significantly different than would be expected based upon a Poisson distribution (P < 0.0001), suggesting the existence of 'hotspots'. All of the 87 simple base substitutions occurred at known mutable sites, but eight were substitutions of a kind that have not previously been reported at these sites. The most frequently mutated sites were cDNA positions 197 and 146, with six and five independent mutations respectively. Four mutations were observed at position 131, and three each at positions 143, 208, 508 and 617. Transitions (52%) were slightly more frequent than tranversions (48%), and mutations at GC base pairs (56%) more common than mutations at AT base pairs (44%). GC > AT was the most common type of base pair substitution (37%). The majority of the mutations at GC base pairs (78%) occurred at sites with G in the non-transcribed strand. All but one of eight mutations at CpG- sites were of the kind expected from deamination of methylated cytosine. Deletion of a single base pair (-1 frameshift) was three times more frequent than insertion of a single bp (+1 frameshift). Almost half (6/13) of the small (3-52 bp) deletions within the coding sequence clustered in the 5' end of exon 2. Short repeats and other sequence motifs that have been associated with replication error were found in the flanking regions of most of the frameshifts and small deletions. However, several differences in the local sequence context between +/-1 frameshift and deletion mutations were also noticed. The present results identify positions 197, 146 and possibly 131 as hotspots for base substitution mutations, and confirm previously reported hotspots at positions 197, 508 and 617. In addition, the earlier notion of a deletion hotspot in the 5'end of exon 2 was confirmed. The observations of these mutational cluster regions in different human populations suggest that they are due to endogeneous mechanisms of mutagenesis, or to ubiquitous environmental influences. The emerging background spectrum of somatic in vivo mutation in the human hprt gene provides a useful basis for comparisons with radiation or chemically induced mutational spectra, as well as with gene mutations in human tumors.      

Compatible leaching effect of Concha Ostreae and some commonly-used Chinese medicinal materials]

OBJECTIVE: Based on a study of Concha Ostreae, to provide some reference for the rational approach to leaching mineral drugs. METHOD: Taking the change rates of compatible leaching and value of A as targets, the compatible leaching effect of Concha Ostreae with Radix et Rhizoma Rhei Praeparata, Radix Scutellariae, Pollen Typhae and Fructus Aurantii lmmaturus was studied. RESULT: If Concha Ostreae and the above cited medicinal herbs are decocted together, the yield of extract may be reduced to a certain extent, but the target composition of Radix et Rhizoma Rhei Praeparata and Fructus Aurantii lmmaturus remains intact, only the content of Radix Scutellariae baicalin may be influenced. CONCLUSION: The relationship of technology with preparation must be taken into consideration when making choice of the proper way to leach Concha Ostreae.     

银杏叶提取物EGb761通过caspase-3抑制TNF-α诱导HeLa细胞凋亡

目的探讨caspase-3的活化在银杏叶提取物EGb761对肿瘤坏死因子-α(TNF-α)诱导HeLa细胞凋亡中的影响.方法采用流式细胞术检测细胞凋亡,Western blot检测caspase-3 p20活性片段,Caspase-3 Colorimetric Assay试剂盒测定caspase-3活性.结果流式细胞术分析结果显示,EGb761在10～40 mg/L终浓度范围内对重组人肿瘤坏死因子-α(rhTNF-α)诱导的HeLa细胞凋亡均有显著的抑制作用(P＜0.01),呈剂量依赖关系;Western blot检测显示,rhTNF-α诱导的HeLa细胞caspase-3 p20活性片段水平增高,能被不同剂量EGb761(10～40 mg/L)明显抑制,且随EGb761浓度增加抑制效果增强;caspase-3活性测定结果显示,EGb761对rhTNF-α诱导的caspase-3活化有显著的抑制作用,且随剂量增加抑制作用增强.结论结果提示,EGb761抑制TNF-α诱导的HeLa细胞凋亡可能与其抑制caspase-3活化有关.     

杜氏盐藻基因组文库的构建

目的　构建杜氏盐藻基因组文库,旨在进一步分离和研究杜氏盐藻基因的结构和功能。方法　采用改进的SDS裂解法提取杜氏盐藻基因组DNA ,通过限制性内切酶Sau3AI进行部分酶切,用T4DNA连接酶将目的片段与噬菌体EMBL3载体臂进行连接后转染大肠杆菌LE3 92。结果　体外包装构建了杜氏盐藻基因组文库,得到重组子数为2 .2×10 4,经测定文库滴度为2 .2×10 5pfu/mL。结论　构建了杜氏盐藻基因组文库,为进一步筛选盐藻重要基因及其序列分析奠定基础。     

抗百日咳毒素单克隆抗体的纯化及应用研究

目的纯化抗百日咳毒素(PT)的单克隆抗体(M cAb),并建立特异、准确的PT定量检测方法。方法采用辛酸-硫酸铵沉淀法和A蛋白亲和层析法纯化杂交瘤细胞腹水,并经阻断抑制试验筛选识别不同表位的M cAb,用于建立定量检测PT的ELISA方法。结果经SDS-PAGE分析,纯化M cAb的纯度均在90%以上,选择二株识别不同抗原位点M cAbs,应用于检测PT的双抗夹心ELISA方法,灵敏度为2.14μg/L,批内变异系数5.85%,批间变异系数9.27%,平均回收率为108.12%,应用该法测定了国内几大生产厂家送检的无细胞百日咳疫苗原液中PT含量。结论获得了纯度高的抗PT M cAb,建立了一种特异、准确的定量检测PT的ELISA方法,并用于无细胞百日咳疫苗原液中PT含量的检测,为无细胞百日咳疫苗的质量控制提供了有力的手段。     

水中嗜肺军团菌分布规律研究

目的　探讨水环境中嗜肺军团菌分布规律及分型特征。方法　采集自然环境及生活环境中各主要水体样品 ,浓缩后经常规细菌培养后的疑似菌株 ,用血清学鉴定与 1 6SrRNA半套式PCR技术双重鉴定进行军团菌和嗜肺军团菌的分型。结果　全部 1 2 6个监测点水样有 2 8个出现军团菌阳性 (其中嗜肺军团菌 2 1个 ) ;自然环境及生活环境监测点军团菌阳性率分别为 32 1 %、2 2 2 % (其中嗜肺军团菌阳性率分别为2 1 4 %、1 6 7% ) ;全年 4 30份水样有 36份军团菌阳性 (其中 2 3份为嗜肺军团菌 ) ,夏、秋季检出率较高 ,春、冬季也有检出 ;空调冷却塔水、淋浴喷头水、公园湖水检出率较高。结论　嗜肺军团菌在自然环境及生活环境各水体中分布广泛。环境温度是军团菌污染的重要因素 ,夏、秋季是军团菌污染和军团病传播的高发季节 ,春、冬季也可发生。公园娱乐水体、空调冷却水、淋浴喷头水等与人群密切接触水体是军团菌污染和军团病传播的高危水体。应尽快采取预防与控制措施以保护广大人群身体健康     

硒对碘过量小鼠肝脏I型脱碘酶活性的影响

目的　研究碘过量摄入对小鼠肝脏I型脱碘酶 (IDI)活性的影响及硒的干预作用。方法　将 4 0只Balb c小鼠按体重随机分为 5组 :正常对照组、碘过量I组 (3mg L)、碘过量I+Se(1mg L)组、碘过量II组 (5mg L)以及碘过量II+Se(1mg L)组 ,分别喂饲碘过量水或碘过量 +硒水以及正常鼠饲料。 3个月后 ,取血、尿及脏器测定相关指标。结果　碘过量组小鼠出现了弥漫胶质性甲状腺肿 ;与正常对照组相比 ,两个碘过量的血清TT4水平显著升高 ,而碘过量II组血清TT3水平显著降低 ;碘可显著降低肝硒水平及I型脱碘酶活性 ,补硒可明显增加碘过量小鼠的肝硒储备 ,抑制碘过量I组脱碘酶活性的降低。结论　碘过量摄入降低小鼠肝硒水平及肝脏I型脱碘酶活性 ,可能是引起血清TT4升高、出现甲状腺肿的原因 ,补硒具有一定的干预作用。     

改良皮下埋藏缝线法重睑形成术

目的:探讨重睑形成术的手术方法和效果。方法:对15例(29眼)单睑者在皮下埋藏缝线法重睑形成的基本原理的基础上,在具体操作技术上用我们改良后的手术方法施行手术。结果:经5～10d和6～12mo的随访观察,除其中1例无力型因年龄大适应症选择不当0.5a后效果不佳;其余全部受术者,恢复后形成重睑皱褶自然,长短基本一致,重睑对称。受术者、施术者、第三者均较满意。结论:改良后的重睑形成术,手术操作简便,效果可靠。是一种具有应用价值的手术方式,值得推广使用。