Effect of morphological abnormalities on blood retinal barrier permeability in diabetic retinopathy

The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (P_BRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the P_BRB by multiple regression analysis. The P_brb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The P_BRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (S_irma) and (2) new vessels (S_neo): p_brb = A – B.S_IRMA – C.S_neo with P_BRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R² = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities.     

血管内皮生长因子在糖尿病大鼠视网膜中的表达

目的 :利用糖尿病大鼠动物模型 ,通过大鼠视网膜中血管内皮生长因子 ( vascular en-dothelial growth factor,VEGF)的表达情况 ,探讨 VEGF在糖尿病视网膜病变 ( diabetic retinopa-thy,DR)发展过程中作用机理。方法 :复制链脲佐菌素 ( streptozocin,STZ)糖尿病大鼠动物模型 ,取不同组、不同时期大鼠视网膜 ,利用免疫组织化学及原位杂交方法 ,检测 VEGF蛋白质及 m RNA的表达情况。结果 :1正常对照组 ( M)、血糖恢复组及糖尿病 1个月组 ( M1)大鼠视网膜均无 VEGF蛋白质及 m RNA的阳性表达 ;2糖尿病 3个月组 ( M3 )未见 VEGF m RNA表达 ,而在内核层及节细胞层有 VEGF蛋白表达阳性 ( 34%) ,此表达与胶质纤维酸性蛋白 ( GFAP)染色阳性细胞相同 ;3糖尿病 5个月组 ( M5) VEGF m RNA表达阳性率为 67%,表达位于视网膜各层 ,内界膜中的表达与 GFAP免疫组化阳性分布相同 ,VEGF蛋白质表达强阳性 ( 89%) ,主要位于内核层、节细胞层的细胞及血管上。结论 :VEGF在 STZ大鼠视网膜中的表达与病程相关 ,而且 VEGF的产生存在着自分泌和旁分泌多种途径     

葛根素联用甲钴胺治疗糖尿病周围神经病变32例

目的 观察葛根素联用甲钴胺治疗糖尿病周围神经病变(DPN)的疗效。方法 将诊断明确的64例DPN患者随机分为治疗组和对照组各32例,两组均给予糖尿病饮食和降糖治疗,治疗组给予葛根素联用甲钴胺治疗,对照组单给予葛根素治疗。10天为一疗程,共治疗两疗程,对两组疗效进行比较。结果 治疗组总有效率和神经传导速度改善均好于对照组(P<0.01),且无明显副作用。结论 葛根素联用甲钴铵治疗DPN比单用葛根素疗效好,值得临床推广应用。     

应用局部皮瓣治疗仰趾畸形

目的:探讨烧、创伤后,足背瘢痕挛缩所致仰趾畸形的治疗。方法:术中将足背瘢痕切除,彻底松解挛缩,将弓弦状伸肌腱切除部分或切断,切除部分挛缩的跖趾关节背侧关节囊,使关节复位,克氏针外固定,在拇指内侧或小趾侧,以跖趾关节处为蒂设计逆行皮瓣,转移覆盖外露的跖趾关节,供区及瘢痕切除后创面行全厚或断层皮片修复。结果:本组7例,均采用逆行皮瓣修复,畸形完全纠正,无继发畸形。结论:应用拇指及小趾侧方逆行皮瓣转移,治疗仰趾畸形可达到满意效果。     

足新型矫形外固定器的研制与应用

[目的]报道一种足新型矫形外固定器的构成和临床应用效果，并与Illizarov外固定器进行对比。[方法]作者研制一种足新型矫形外固定器，由3对、6根金属杆组成，每根金属杆具有单独的延长、加压功能。利用固定在胫骨、跟骨、跖骨共4根克氏针，将小腿、足部两侧成三角形连接为一体，进行三维矫形。2004年1月以来，使用该外固定器治疗先天性和后天获得性、不同原因引起的132马蹄内翻足畸形。现将随访12个月以上病例62例（85足）予以报道。[结果]根据Garceau分级标准、结合患者足形态与功能表现评定：优：40足；良：40足；可：5足；差：无。优良率为94．1％。[结论]足新型三维矫形外固定器治疗幼儿、青少年马蹄内翻足安全、可靠、有效；比Illizarov外固定器结构简单，安装方便、省时；患者感到舒适，轻便；成本低、价格便宜；适合国内有条件的医疗单位广泛应用。     

A review of the effects of external pressure on skin blood flow

The human foot is a complex mechanical structure consisting of bones, ligaments and joints. They act together to provide a robust system capable of absorbing and dissipating the intermitted pressure that is subjected to its plantar surface during walking to prevent soft tissue breakdown. Current studies suggest that plantar foot pressure may lead to soft tissue breakdown (e.g. neuropathic ulceration) and hence research has so far concentrated on investigating the mechanical effects of plantar foot pressure on the foot’s integrity. This has been possible through the widely available pressure and force platforms as well as in-shoe pressure systems. However, to understand how plantar foot pressure causes soft tissue breakdown it is vital to investigate both the physiological–mechanical interactions between the skin and plantar foot pressure. This review suggests that with the current advances in technology, the physiological response of skin blood flow to mechanical plantar foot pressure should be investigated and correlated further, both during static and dynamic loading, by developing a new system capable of either measuring both variables simultaneously or by synchronising two systems in real time.     

Activity and distribution of phosphoinositidase C in rat sciatic nerve.

The hydrolysis of phosphatidylinositol-4,5-bisphosphate (PIP2) by rat sciatic nerve cytosolic phosphoinositidase C [phosphoinositide-specific phospholipase C (PIC)] was studied at neutral pH and at ionic concentrations that approximate intracellular conditions. The principal water-soluble product formed was shown to be inositol trisphosphate by anion exchange chromatography. The maximum hydrolysis rate (2.5 nmol/min/mg protein) was achieved at less than 100 nM Ca2+. Hydrolysis was markedly increased to 15 nmol/min/mg protein by inclusion of K+ in the reaction mixture. In the presence of 200 mM K+, the optimum Ca2+ was increased to approximately 600 nM. Higher Ca2+ concentrations progressively inhibited PIP2 hydrolysis. Mg2+ also inhibited the reaction, but the presence of equimolar amounts of ATP and Mg2+ had no effect. Appreciable degradation of phosphatidylinositol-4-phosphate (PIP) also occurred in the nanomolar Ca2+ range, whereas breakdown of phosphatidylinositol (PI) required millimolar Ca2+. The presence of PIP but not PI inhibited PIP2 hydrolysis. Upon subcellular fractionation of nerve, more than 50% of recovered PIC activity was in the cytosol and about 20% was located in a myelin-enriched fraction. Using PIP2 as substrate, PIC activities in nerves from normal and streptozotocin-induced diabetic animals were not different. However, the myelin-associated enzyme from diabetic animals was more labile to freezing and thawing.     

Neuropathy in children and adolescents with diabetes mellitus

Nerve conduction velocities were studied in the median, posterior tibial, radial and sural nerves of 50 juvenile diabetics, average age 13 +/- 1.3 years and mean duration of diabetes 2.3 +/- 1.4 years. Motor conduction velocity (MCV) in the median nerve was reduced in 10% of the subjects, and in the posterior tibial in 32%. Sensory conduction velocity (SCV) in the radial nerve was reduced in 30% of the subjects, and in the sural in 44%. No relationship was found between the reduction in conduction velocity and the duration of diabetes; nevertheless, a correlation was observed between this reduction and the degree of glycaemic control represented by the glycosylated haemoglobin concentration. The authors emphasize the importance of good glycaemic control for the prevention of diabetic neuropathy.     

实验性糖尿病大鼠肾脏损害和脂质过氧化物水平的动态研究

动态观察实验性糖尿病大鼠于发病后２、４、６、１２、和１６周肾脏损害指标和肾脏脂质过氧化物（ＬＰＯ）水平的变化。结果表明，发病后各观察时间．或糖尿病大鼠２４ｈ尿Ａｌｂ、β２──ＭＧ排泄量和尿ＮＡＧ活性均明显增高，而２４ｈ尿ＴＨＰ排泄量显著降低，肾脏ＬＰＯ水平明显升高。其中尿ＮＡＧ活性、ＴＨＰ排泄量和肾脏ＬＰＯ水平均随病程延长而更趋明显。这些结果提示，在糖尿病早期除有肾小球功能损害外，肾小管也明显受损，过氧化损伤在糖尿病肾病发病中可能是重要因素之一。尿Ａｌｂ、β２──ＭＧ、ＴＨＰ含量和ＮＡＧ活性可作为糖尿病肾病早期肾损害的敏感指标。