Somatic instability of the myotonic dystrophy (CTG)n repeat during human fetal development

Myotonic dystrophy is characterised by the striking level of somatic heterogeneity seen between and within tissues of the same patient, which probably accounts for a significant proportion of the pleiotropy associated with this disorder. The congenital form of the disease is associated with the largest (CTG)n repeat expansions. We have investigated the timing of instability of myotonic dystrophy (CTG)n repeats in a series of congenitally affected fetuses and neonates. We find that during the first trimester the repeat is apparently stable and that instability only becomes detectable during the second and third trimesters. In our series repeat instability is apparent only after 13 weeks gestational age and before 16 weeks. The appearance of heterogeneity shows some tissue specificity, with heart most commonly having the largest expansion. The degree of heterogeneity is not correlated with initial expansion size as gauged by chorionic villus and blood (CTG)n repeat sizes.      

Atrophodermia vermiculata: case report and review of the literature

A 21-year-old woman with an 11-year history of symmetric reticular atrophy on both cheeks, pre-auricular areas, and forehead is presented. The depressions gave a worm-eaten appearance to the skin. Histopathological findings from a biopsy specimen of lesional skin revealed an atrophic follicle. The connective tissue showed mild inflammation in perifollicular and perivascular distribution. The hair follicle was widely dilated and was filled with a keratotic plug. This case points out many of the outstanding clinical and histopathological features of atrophodermia vermiculata as described previously. Atrophodermia vermiculata appears to be one of a group of closely related conditions characterized by keratosis pilaris and atrophy of the skin.     

几丁糖与人工骨联合应用预防椎板切除术后硬膜外粘连的实验研究

目的:观察椎板切除术后用几丁糖(CHT)的同时在椎板缺损处植入磷酸三钙人工骨(TCP)预防硬膜外瘢痕粘连的效果。方法:40只纯种日本大耳白兔随机分成A、B、C、D四组,制作L4椎板损伤模型。A组硬膜外涂布生理盐水,B组硬膜外涂布几丁糖,C组硬膜外覆盖人工骨,D组硬膜外涂布几丁糖的同时加人工骨覆盖。术后12周对椎板切除部位进行大体观察、组织学观察及生化检查,比较各组间瘢痕形成和粘连情况。结果:B、C、D组的改良Rydell-Balazs粘连韧度评分、胶原含量及改良Nussvaum组织学评分均优于A组(P<0.01),D组优于B组与C组(P<0.05),B组与C组无显著性差异(P>0.05)。结论:联合应用几丁糖和人工骨能有效预防硬膜外瘢痕粘连的形成,比单独应用几丁糖和人工骨预防效果好。     

Extended wear disposable soft contact lenses as an alternative to photorefractive keratectomy: Report of 4 years experience

Purpose: To establish whether; in a well-informed population, the use of extended wear disposable soft contact lenses (EWDSCL) poses an unacceptable risk to vision and corneal health due to complications associated with their use. Methods: A 4 year retrospective review of EWDSCL, involving 371 patients in Melbourne from a single general ophthalmology practice. The important aspects of this group were that all patients were given written instructions about the methods of ensuring initial and ongoing cleanliness of lenses, no lenses were cleaned and reinserted, and no solutions other than the saline in the original packaging, and comfort drops, were used. Two types of EWDSCL were used, in powers from - 9.0 to + 6.0 D, and with an initial aim of 4 weeks uninterrupted extended wear. Follow-up was from 2 to 52 months, with an average of 24 months. Results: Of the 354 patients followed up, 236 (66%) regularly wore them on an extended overnight basis, and of these 180 (76%) wore them for the suggested 4 week period before renewal of lenses. In the 471 eyes of 236 patients, adverse reactions occurred at the following rates: marginal infiltrates (12 cases, 2.5%); corneal oedema (10 cases, 2%); peripheral corneal vascularization (2 cases, 0.4%); and presumed infective keratitis (1 case, 0.2%). No eyes lost one or more lines of Snellen acuity. Conclusions: When disposable soft contact lenses do not come into contact with cleaning solutions, saline from bottles or aerosol cans, or storage cases, their use on an extended wear basis (up to 4 weeks continuous) appears to be associated with a low risk of minor or major complications. The results of this review indicate that controlled usage of EWDSCL is safer than previous reports have indicated.     

中西医结合治疗老年高脂血症

目的：探讨中西医结合治疗高脂血症的临床疗效。方法：符合高脂血症标准的老年患者120例，随机分为A、B2组各60例，A组采用益肾化淤、利湿化浊为主的中药及西药辛伐他汀片治疗；B组则单纯用辛伐他汀片治疗。治疗前及治疗4周后2组均行全套血脂水平测定。结果：与B组比较，A组血清总胆固醇（TC）及甘油三酯（TG）均明显下降，HDL明显上升（均P〈0．05）；A组临床控制率明显高于B组（P〈0．05）；治疗后A组患者未见肝功能损害，B组转氨酶及转肽酶轻度异常，2例。停药3个月后，A组复发率低于B组（2．2％、8．8％，P〈0．05）。结论：中西医结合治疗老年高脂血症的临床效果明显优于单一的一种治疗方法，值得临床进一步推广应用。     

Regulation of intercellular adhesion molecule-1 gene expression involves multiple mRNA stabilization mechanisms: effects of interferon- gamma and phorbol myristate acetate

Although the intercellular adhesion molecule-1 (ICAM-1) is constitutively expressed at a low level on a subpopulation of hematopoietic cells, on vascular endothelium, on fibroblasts, and on certain epithelial cells, it is dramatically increased at sites of inflammation. Interferon-gamma (IFN-gamma) and phorbol myristate acetate (PMA) are known to increase the expression of ICAM-1 on many cell types. Because both human and murine ICAM-1 mRNAs contain putative destabilizing AUUUA sequences in their 3' untranslated regions (UTRs), we examined the role of mRNA stability in the regulation of ICAM-1 gene expression. The treatment of the murine monocytic cell line P388D1, which constitutively expresses ICAM-1 mRNA at a low level, with IFN- gamma or PMA rapidly enhanced the level of ICAM-1 mRNA and dramatically prolonged its half-life. To determine whether the putative destabilizing sequences are responsible for this effect of IFN-gamma and PMA, fibroblast L cells were transfected with either the full- length ICAM-1 cDNA or a truncated form (ICAM-1 delta 3) lacking the putative destabilizing AUUUA sequences. Although ICAM-1 delta 3 mRNA was more stable than the full-length ICAM-1 mRNA, IFN-gamma treatment induced the accumulation of both mRNA species and prolongation of their half-lives. The transplantation of the ICAM-1 delta 3' UTR into a stable ICAM-2 mRNA rendered it unstable, and it was unresponsive to IFN- gamma. Therefore, the treatment with IFN-gamma stabilizes the otherwise labile ICAM-1 mRNA, but the IFN-gamma-responsive sequence may at least in part reside within the protein coding region. PMA also upregulated ICAM-1 gene expression by mRNA stabilization. However, unlike IFN- gamma, PMA treatment only increased the level of the full-length, but not of the truncated, ICAM-1 mRNA. This shows that the PMA-responsive element is located within the 3'UTR. Furthermore, the effect of PMA on ICAM-1 delta 3 mRNA was recovered by ligating multiple AUUUA sequences derived from a heterologous gene fragment. The stability of this chimeric mRNA and the full-length ICAM-1 mRNA was markedly increased by PMA treatment, indicating that the AUUUA multimers in the 3'UTR are important in the PMA-induced upregulation of ICAM-1 mRNA.     

Diaziquone given as a continuous infusion is an active agent for relapsed adult acute nonlymphocytic leukemia

Diaziquone given as a bolus has not been effective in patients with relapsed or refractory leukemia. Because of in vitro data suggesting enhancement of diaziquone-induced cytotoxicity for human and murine leukemia cells with increased duration of drug exposure and the relatively short terminal plasma half-life of diaziquone, 49 patients (34 acute nonlymphocytic leukemia [ANLL], six chronic myelogenous leukemia in blast crisis [CML-B], five acute lymphocytic leukemia [ALL], four 2 degrees ANLL) with leukemia were given diaziquone as a continuous infusion for seven days. The maximum tolerated dose was 28 mg/m2/d for seven days. The dose-limiting toxicity was the duration of bone marrow aplasia (median, 49 days to greater than 500 PMNs in responders; range, 28 to 101 days). Nonhematologic toxicity was minimal. Responses occurred only in patients with relapsed ANLL, of whom 26 were treated at effective doses. There were six complete responses (CR) (23%) and two partial responses (PR) (8%), although five of eight responders never achieved platelet counts greater than 100,000/microL. Thrombocytopenia in these patients was felt to be a manifestation of diaziquone effect, not persistence of leukemia. The median duration of CR was 195 days (range, 88 to 860+). One patient had active CNS leukemia at the start of treatment and has had a durable (28+ month) CR in both sites of disease. Diaziquone produced prolonged aplasia in patients with secondary ANLL and CML-B (five of ten patients died aplastic), whereas patients with ALL all had regrowth of leukemia and two failed to become aplastic. The lack of significant nonhematologic toxicity and the activity in patients with relapsed ANLL render diaziquone of interest as second-line therapy or consolidation therapy in first remission for patients with ANLL.