Squint in monozygotic twins

In a group of monozygotic twins, in which at least one of the pair squinted, strabismus was observed in both twins in only about half of the cases. Within the concordant group there was variation in the way in which the anomaly became manifest.Author's address: Ophthalmological Clinic Academic Hospital Oostersingel 59 Groningen The Netherlands     

Familial aggregation of fainting in a case-control study of neurally mediated hypotension patients who present with unexplained chronic fatigue.

AIMS: We hypothesized that family history of fainting is a risk factor for adult-onset neurally mediated hypotension (NMH) in patients who present with chronic fatigue rather than fainting. METHODS AND RESULTS: A nested case-control study of Gulf War veterans gathered fainting histories directly from 197 first-degree relatives of 16 fatigued NMH cases, 26 fatigued controls, and 17 healthy controls. NMH status was determined by tilt testing. Female relatives of fatigued controls reported more fainting than female relatives of cases (P<0.01); there were no significant differences in the frequency of fainting in male relatives by case or control status, or in either gender by age at first faint or by familial relationship to the proband. The odds of NMH patients giving any family history of fainting were 0.56 (95% CI 0.15, 2.07). Recurrence risks calculated using lifetime prevalences of fainting in male military personnel of similar age to our participants were low (1.5-1.7) and did not differ by case or control status. CONCLUSION: Family history of fainting is not a risk factor for adult-onset NMH in fatigued veterans. Our findings may differ from other studies of familial aggregation in NMH because of study methods or because NMH-fatiguers may differ from NMH-fainters.     

心血瘀阻证遗传倾向的调查分析

目的分析冠心病、高血压病、糖尿病性心脏病心血瘀阻证的遗传倾向。方法运用家系分析法对 5 4例心血瘀阻证患者和 5 4例健康人的家族进行了遗传分析 ,检测一级亲属发病率、遗传率 ,及 3种父母婚配类型子女发病的相对危险度 (RR)及其 95 %可信区间 ( 95 %CI)。结果心血瘀阻证患者的一级亲属发病率为 7.62 %,健康对照组为 0 .95 %,两组比较有显著差异 (P <0 .0 0 1 ) ;心血瘀阻证的遗传率为 ( 67.4±6.89) %;以“双亲均正常”组为对照 ,“亲代一方患病”组的RR值为 3 .46,“亲代双方患病”组的RR值为 5 .84,提示子女患心血瘀阻证与亲代双方患病有因果关系。结论心血瘀阻证可能是一种具有遗传倾向的“多基因证”。     

Radiation management of bilateral retinoblastoma: Theneed to preservation

Thirty-four patients with retinoblastoma were treated in the Radiation Therapy Department of the University of Oregon Health Sciences Center from 1944 to 1978. Twenty-five of these patients had bilateral disease. Most patients were treated with megavoltage equipment and received doses of 5000 rad in 5 weeks. According to the lifetable method, five year survival was 67.6 % ; it increased to 85.7 % if patients who were treated with orthovoltage equipment were excluded. Seventy-one percent of evaluable patients had useful vision at 5 years; an additional two patients had useful vision for two years after radiation therapy. The value of even limited vision during this critical time of sensorimotor and psychological development is discussed. Orthovoltage equipment should not be used to irradiate patients with retinoblastoma.     

Genetic and Constitutional Influences on Bone Turnover Markers: A Study of Male Twin Pairs

Biochemical markers of bone turnover originating from type I procollagen synthesis or type I collagen breakdown were examined in men using a classic twin study design based on monozygotic (MZ) and dizygotic (DZ) twins. The aim was to estimate the influence of heredity (genes and shared family childhood elements) and constitutional factors in determining procollagen type I amino-terminal propeptide (PINP), type I collagen carboxy-terminal telopeptide (ICTP), and urinary amino-terminal type I collagen telopeptide (NTx) marker levels in a sample of in 98 MZ and 108 DZ male twin pairs. We are not aware of any prior studies conducted in men that address the influence of genetic factors on bone turnover marker variability. The findings support a dominant role for heredity in the variation of bone resorption marker levels in men, with additive genetic effects explaining two-thirds of the variance in the bone resorption markers NTx and ICTP. Genetic factors may contribute less for PINP, a marker of bone formation. The genetic loci influencing PINP or NTx and body weight/disc axial area, although related in part, appeared to be largely independent, indicating that genetic effects on bone turnover are unlikely to be to a large degree a result of genetic regulation of individual body weight.     

高血压家族史儿童血压水平的研究

目的：了解有高血压家族史儿童的血压水平。方法：对167例有高血压家族史的儿童测量血压,以175例无高血压家族史的健康儿童作为对照。结果：与对照组比较,有家族史的儿童收缩压和舒张压明显增高,高血压检出率明显增高（2．57％：15．13％,P〈0．01）。有早发高血压家族史的儿童与非早发家族史儿童比较,收缩压和舒张压更高,高血压检出率更高（21．54％：12．94％,P〈0．01）。结论：有高血压家族史儿童血压水平较无高血压家族史儿童高,以有早发高血压家族史儿童更明显,提示成年后发生高血压的危险性显著升高。     

凝血因子V莱顿突变对载脂蛋白E基因敲除小鼠动脉粥样硬化的影响

目的 评价凝血因子V莱顿突变(FvL)对动脉粥样硬化的影响.方法 建立FvL与载脂蛋白E(ApoE)基因复合突变小鼠,并分析其动脉粥样硬化形成和纤维蛋白沉积情况.结果 小鼠52周龄时,FvL纯合子ApoE-/-(FvQ/Q APOE-/-)小鼠动脉粥样硬化范围明显大于野生型ApoE-/-(Fv+/+ApoE-/-),小鼠,FvQ/Q ApoE-/-比Fv+/+ApoE-/-为(5.0±1.1)%比(2.2±0.4)%,P＜0.005;FvL杂合子ApoE-/-(FvQ/+ApoE-/-)小鼠动脉粥样硬化范围位于FvQ/Q ApoE-/-小鼠和Fv+/+ApoE-/-小鼠之间,与两者的差异均无统计学意义,FvQ/+ApoE-/-比FvQ/QApoE-/-为(2.9±0.6)%比(5.0.±1.1)%,P＞0.05,FvQ/+ApoE-/-比Fv+/+ApoE-/-为(2.9±0.6)%比(2.2±0.4)%,P＞0.05.FvQ/Q ApoE-/-小鼠动脉粥样硬化斑块内的纤维蛋白沉积同样明显高于Fv+/+ApoE-/-小鼠,FvQ/Q ApoE-/-比Fv+/+ApoE-/-为(3.4±0.5)%比(1.8±0.4)%,P＜0.05.结论 FvL纯合子明显增加ApoE-/-小鼠动脉粥样硬化程度及动脉粥样硬化斑块内的纤维蛋白沉积,提示FvL突变可能是重要的促进动脉粥样硬化形成的因素,临床上患者出现严重的动脉粥样硬化可能合并FvL遗传基因缺陷.     

连接蛋白相关遗传性皮肤病的基因突变

连接蛋白是构成缝隙连接的主要蛋白质,它在细胞间通讯系统中发挥着重要的作用.连接蛋白的基因突变可以引起多种遗传性皮肤病,与连接蛋白相关的一系列遗传性皮肤病主要累及来源于外胚叶的组织,其临床表现各异,部分症状又相互重叠.同一表现型可由不同的突变引起,相同的突变也可出现不同的临床表现型.     

偏头痛的基因研究新进展

偏头痛是一种临床较常见、慢性、反复发作的血管神经性头痛。偏头痛的发病机制目前尚未完全明确,病因也较为复杂,遗传、饮食、内分泌以及精神因素等均与偏头痛的发病有一定关系。偏头痛有明显的家族聚集性,但偏头痛的遗传方式尚不完全清楚,到目前为止,家族性偏瘫性偏头痛是唯一已知相关遗传学特征和致病基因的偏头痛,在家族性偏瘫性偏头痛中,目前已鉴定出三个致病基因位点。除家族性偏瘫性偏头痛基因外,偏头痛与5-羟色胺、一氧化氮合酶等基因也有一定相关性,但尚未得出一致性的结论。     

妊娠期糖尿病的发病机制

妊娠期糖尿病（GDM）的发病率逐年递增,经典观点认为其发病机制是在妊娠初期胎儿获取葡萄糖量增加,母体雌激素、孕激素分泌增加,导致胰岛素分泌增多,造成高胰岛素血症,在孕中后期,胎盘激素随孕周增加而分泌增多,具有拮抗胰岛素的作用,使母体外周组织对胰岛素的敏感性逐渐降低.GDM的发生还可能与遗传易患性、炎性因子、细胞因子等有关,而母亲年龄、孕前体质量、受教育程度与职业也可影响GDM的发生和发展.