Diagnosis and management of Hirschsprung's disease. A 25 year perspective

The demographic data and the distribution of the extent of involved bowel in Hirschsprung's disease have remained unchanged over the past 25 years and are similar to those reported by others. The age at which the diagnosis was established decreased initially but increased in the last 10 year period. This increase has been accompanied by an increase in the number of breast-fed infants. Definitive operation for Hirschsprung's disease is now usually performed in children less than 18 months of age. The procedures used were selectively applied in the most recent 10 years. Arbitrary dependence on a single procedure is no longer appropriate and individualized judgment should be used in the application of specific treatment alternatives in the surgical management of Hirschsprung's disease. Mortality after definitive operation is now confined to problems other than Hirschsprung's disease. The patient with undiagnosed Hirschsprung's disease may not survive enterocolitis despite aggressive contemporary resuscitative treatment.     

Radial keratotomy: an overview of the Kansas City study

The first 290 consecutive eyes (192 patients) to undergo radial keratotomy by one surgeon were evaluated prospectively. All had had complete preoperative evaluation and 269 (93%) were examined one or more years after surgery. Preoperatively, all patients except one had worse than 20/100 uncorrected visual acuity, 65% had less than 20/400, and mean spherical equivalent (SE) was -4.8 diopters. One year postoperatively, 40% of the patients had uncorrected visual acuity of 20/20 or better and 83% had 20/40 or better. The mean change in SE after 1 year was 5.0 diopters, and 60% of eyes were within 1 diopter of emmetropia. Keratometric changes paralleled refractive changes, and both appeared stable within 1 to 3 months. Complications were few and most were transient or well-tolerated. One case of presumably viral disciform keratitis occurring 8 months postoperatively had a three Snellen line decrease in best-corrected acuity 1 year postoperatively. Factors affecting refractive outcome were studied using stepwise multiple regression analysis. Size of the optical zone, depth of incision, patient age, patient sex, intraocular pressure, number of incisions, preoperative average keratometry, and corneal diameter were each found to affect clinical outcome significantly.     

Is growth hormone a radioprotective agent?

There is currently substantial clinical interest in growth hormone (GH) as a protective agent against radiation-related normal tissue injury. To further assess the potential radiation injury-preventive effects of GH, these effects were studied in rats by using a radiation-induced skin injury model. Group 1 received neither GH nor irradiation (control group). Group 2 received 30 Gy of gamma irradiation as a single dose to the right hind legs of the rats (radiation group). Group 3 and 4 received the same irradiation plus either 0.01 U/kg/day GH (RT + 0.01 GH group) or 0.02 U/kg/day GH (RT + 0.02 GH group) subcutaneously. Clinically and histopathologically, acute skin reactions were assessed by two independent experts in radiation oncology and pathology, respectively. Irradiation increased dermatitis in rats when compared with the control group. The severity of radiodermatitis in the rats in the RT + 0.01 GH and RT + 0.02 GH groups was significantly lower than that in the RT group; radiodermatitis developed earlier in the RT group than in the other groups. GH was efficacious in preventing epidermal atrophy, dermal degeneration such as oedema and collagen fibre loss, and hair follicle atrophy, but not better than in the control group. These results are preliminary to studies that will be performed with higher doses of GH in radiation-treated cancer patients, with the aim of reducing radiation-induced toxicity.     

人白血病HL60细胞的分化状态对细胞凋亡的影响

用细胞培养和流式细胞术等方法,研究人白血病HL60细胞诱导分化后,对三尖杉酯碱(Har)和喜树碱(Cam)诱导细胞凋亡的影响。结果表明,12-豆蔻酰及13-乙酸佛波酯以16nmol·L^-1浓度处理HL60细胞24h,细胞向单核/巨噬细胞方向分化,阻断于G_{1期;分化细胞抗Har和Cam诱导的细胞凋亡,但其c-myc基因的表达无变化。1.4%二甲基亚砜处理HL60细胞48h,细胞向粒细胞方向分化,阻断于G1期;分化细胞抗Cam,而不抗Har诱导的细胞凋亡;分化细胞的c-myc基因表达明显下降。结果提示,人白血病HL60细胞的分化状态,明显影响三尖杉酯碱和喜树碱诱导的细胞凋亡,但可能与c-myc基因的表达变化无关。}     

内镜下扩大经鼻蝶入路至斜坡区的解剖学研究

目的探索内镜下经扩大鼻蝶入路显露斜坡区的可行性,为切除斜坡区病变提供解剖学参考。方法在10例成人头部固定标本上,内镜下模拟扩大经鼻蝶手术入路显露斜坡区,观察有关显微解剖标志。结果扩大经鼻蝶内镜入路可磨除从鞍后到斜坡、枕骨大孔前缘的骨性结构;可显露斜坡区腹侧硬膜下的椎基底动脉及其分支、后交通动脉及其与大脑后动脉汇合处、动眼神经、脑干腹侧等结构。此入路的手术标志主要包括:蝶筛隐窝、蝶窦开口、视神经隆突、颈内动脉隆突与颈内动脉视神经隐窝、咽结节、枕骨大孔前缘。结论内镜下扩大经鼻蝶手术入路可充分显露鞍后-斜坡区的腹侧硬膜下结构,适用于此区病变的手术治疗。