先天性马蹄内翻足Ponseti治疗初跟腱手术的预测

目的探讨先天性马蹄内翻足（CCF）患儿治疗前预测患儿行跟腱手术的可行性。方法96例CCF（148足）患儿,均依据Ponseti方法治疗,平均（5.7±1.3）次石膏矫正后,背屈活动≤15°或Pirani评分HS（后足评分）≥1,MS（中足评分）〈1的患足需行跟腱切断手术。石膏去除后需佩戴外展支具。结果经过系列石膏矫正后,148足中125足（84.5%）行跟腱切断术,23足（15.5%）未行跟腱手术。在治疗初有102足（68.9%）Pirani评分≥5分,其中93足（91.2%）经系列石膏矫正后行跟腱手术。手术组跟腱愈合佳,跖屈有力。结论在治疗初Pirani评分≥5分时91.2%患儿需要跟腱手术,CCF患儿初次来诊时,对患足行Pirani评分,即可预测其是否需行跟腱手术。在治疗初预先判断患儿是否需行跟腱手术则既有利于医师了解治疗进展,又能更好地与家长沟通配合治疗进程。     

有限切开内固定结合石膏外固定治疗复杂Pilon骨折

目的探讨复杂Pilon骨折延期切开有限内固定结合石膏外固定治疗的临床疗效。方法对26例复杂Pilon骨折(Ruedi-AllgowerⅢ型)均行延期切开有限内固定结合石膏外固定治疗。结果术后发生切口感染4例,3例经植皮治愈,1例经反复换药2.5个月,3个月后取出内固定物后愈合。骨折延迟愈合2例,均为大块髂骨植骨,髂骨面重建踝关节面患者,术后1.5年骨折愈合。26例均获随访,平均31(22~56)个月,按Mazur评分法评定疗效:优10例,良12例,可4例,优良率为84.6%(22/26)。结论根据骨折类型和软组织条件,采用延期有限切开内固定结合石膏外固定治疗复杂Pilon骨折能有效减少局部并发症,并获得较好的踝关节功能。     

Strong and light plaster casts?

Three geometries of volar slab plaster cast for the stabilisation of wrist fractures were investigated. It was found that by moulding reinforcement ridges on the inferior surface of the slab the strength and stiffness could be doubled with only a 20% increase in weight. It was discovered that to provide the same increase in strength with a traditional cast the entire thickness of the cast would have to be doubled, with a 100% increase in weight that would be cumbersome to most users. Bending theory is presented in a simple manner to allow clinicians to understand how reinforcement mouldings can improve the strength and stiffness of plaster casts without adversely influencing weight, or cost.     

Effect of endothelin-1 on regional kidney blood flow and renal arteriole calibre in rabbits

1. Medullary blood flow (MBF) is important in the long-term control of arterial pressure. However, it is unclear which vascular elements regulate MBF. 2. Exogenous endothelin (ET)-1 decreases cortical more than medullary blood flow. We hypothesized that ET-1 would therefore constrict afferent (AA) and efferent arterioles (EA) of juxtamedullary glomeruli less than those of cortical glomeruli. 3. Mean arterial pressure, renal blood flow and cortical (CBF) and medullary (MBF) blood flow, via laser-Doppler flowmetry, were measured before and after intrarenal ET-1 (2 ng/kg per min; n = 6) or vehicle (n = 6) in anaesthetized rabbits. Kidneys were perfusion fixed, vascular casts formed, lumen diameters measured via scanning electron microscopy and relative resistance calculated. 4. Mean arterial pressure was not significantly affected by ET-1 infusion. Cortical glomerular arteriole lumen diameters were significantly reduced in the ET-1-infused group (AA approximately 30%, EA approximately 18%; PA < 0.01), compatible with the decrease in CBF (42 +/- 3%; PGT < 0.01). Juxtamedullary arteriole lumen diameters were also significantly reduced in the ET-1-infused group (AA approximately 34%, EA approximately 21%; PA < 0.01); however, MBF did not decrease. 5. In conclusion, our data suggest that juxtamedullary arterioles are not of primary importance in the regulation of MBF because, despite reductions in juxtamedullary arteriole diameters in response to ET-1, MBF was not decreased.     

人大脑内血管铸型的显微解剖观察

应用6212-Ⅲ型手术显微镜,观察了灌注ABS的10个儿童脑半球的脑内血管,并用TSM-Ⅰ型扫描电镜进行了观察。 1.软膜动脉网为不规则的吻合网,网眼内有许多未梢支并未吻合,而直角弯曲穿入脑实质。穿入点多沿脑回纵行排成非直线的两行,且多偏于一侧。2.软膜静脉网多在动脉网深面,汇成较大的支以后才越至动脉网的浅面。3.皮质动脉平均直径44.30±6.28μm,可由各级分支直接发出,垂直穿入,丛密如刷毛样。4.皮质静脉属支汇集成倒置的宝塔松样。5.髓质动脉长短粗细不一,平均直径158.20±75.71μm,在脑回顶穿入的是直的,在脑沟穿入的,穿过皮质后有不同程度的弯曲。穿经皮质无分支,中段直角分支呈“T”形分岔,深段又锐角分支如树根样,与中央动脉形成广泛的吻合。还发现不少波浪形扭曲的髓质动脉。本文还把这些动脉的铸型标本经扫描电镜观察。对髓质静脉和中央动脉等也进行了显微解剖和描述。     

Development of the retinal circulation in the pig

Retinal angiogenesis was studied in 300 eyes of 150 porcine fetuses by means of semithin histologie sections and vascular corrosion casts. In the embryonic and early fetal period, the retina is avascular and nourished via diffusion from the choriocapillaris and the vascular tunic of the lens. The development of the inner vascular plexus of the retina occurs in three different stages. In the first stage (angioblast phase), during gestational weeks 6–7, mesenchymal precursor cells arising from the arterial and venous circle around the optic nerve invade the nerve fiber layer of the retina via the optic disc border. They form a network of angioblasts that gives rise to an immature capillary network in the second stage (angiogenesis phase). This vascular monolayer is located within the nerve fiber layer and reaches the ora serrata around gestational weeks 9–10. Initially, the immature retinal capillaries have an irregular appearance with wide lumina and relatively small intercapillary meshes. Subsequently, the lumina become smaller by involution and atrophy. In the third stage (maturation and remodeling phase) the immature blood vessels differentiate into retinal arterioles, capillaries and venules. From gestational week 11 onwards, the larger retinal arterioles are surrounded by a distinct periarteriolar capillary-free zone. The three stages start at the optic disc and extend centrifugally towards the retinal periphery. The development of the outer vascular plexus is essentially different from the angiogenesis of the inner vascular plexus. The outer retinal vessels that are located in the inner nuclear layer arise from previously developed capillaries and venules located in the inner vascular plexus. Moreover, the development of the outer vascular plexus starts at the macula and proceeds along with the maturation of the neural retina.     

The microvasculature of the 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumour

Summary We examined the microvasculature of the 7,12-dimethylbenz(a)anthracene (DMBA)-induced rat mammary tumour by scanning electron microscopy of corrosion casts. An elaborate vascular envelope predominantly consisting of sinusoidal and venular vessels was formed around each tumour nodule. These vessels exhibited various abnormal features, whereas arterioles appeared normal. The abnormal vessels possessed many globular outpouches, possibly representing the site of angiogenesis. An additional capillary layer was seen in the marginal boundary between the tumour and host tissue. The lack of centrifugally extruding vessels in this layer may indicate a poor potency for vascular spread of tumour cells into the adjacent normal tissue. Looplike or glomerular ingrowths were frequently found on the inner aspect of the vascular capsule, which eventually developed into a dense intranodular plexus. Intranodular vessels often showed focal narrowing, tapering and/ or rupturing, possibly due to increased tissue pressure caused by proliferating tumour cells. Those surrounding necrotic portions were extremely dilated with occasional periodic varicosities. The features may be associated with the lessening of the tissue pressure resulting from tumour cell collapse.