Changes at the glomerular tip: a feature of membranous nephropathy and other disorders associated with proteinuria

Renal biopsies and post-mortem kidneys were examined for segmental lesions at glomerular tips, consisting of adhesion of the tuft to Bowman's capsule with an area of intra-capillary foam cells or hyaline material or sclerosed material. Of 72 consecutive renal biopsies showing membranous nephropathy, 46 (64 per cent) had tip changes. Such changes were correlated with the presence of acute tubular damage and with later stages of the nephropathy, but otherwise seemed unrelated to any particular clinical or pathological feature. Fourteen other patients were identified whose renal biopsies showed tip changes in glomeruli that had segmental or global mesangial hypercellularity not of a well-recognized type such as IgA nephropathy. These patients had persistent proteinuria unresponsive to steroids. Tip changes were also seen in several miscellaneous conditions including IgA nephropathy and diabetic glomerulosclerosis. These findings demonstrate that tip changes are seen in many disorders of the kidney associated with proteinuria and represent a previously unrecognized common response of the glomerulus to some insult, the glomerular tip lesion, as originally defined, is distinguished by the apparent normality of tufts except for the tip changes and can be regarded as presumed minimal change nephropathy plus tip changes and when tip changes are seen, the most important factor determining the prognosis is the condition of the rest of the glomerular tuft.     

成人肾小球极垫细胞区的微血管构筑

本文用3例成人新鲜肾脏,经肾动脉灌注5％和10％ABS丁酮溶液。硬化后,取小块样品,经50％盐酸腐蚀。切取肾动脉及其细小分支铸型,镀膜后,置S-450或S-520扫描电子显微镜下观察、摄片。极垫细胞区的毛细血管网,位于肾小球门处,全貌可呈三角形、四边形或逗点状。此区的毛细血管网,网眼多呈圆形、卵圆形、三角形或四边形,网眼比较细小,其直径常小于毛细血管自身的管径。极垫细胞区的微血管主要来自入球小动脉,后者常穿经此区微血管的中央部,但也可呈偏心位。极垫细胞区的微血管与肾小球的微血管直接延续。本文对极垫细胞区微血管的功能意义进行了讨论。     

Calbindin D28K immunoreactive neurons in vomeronasal organ and their projections to the accessory olfactory bulb in the rat

The vomeronasal system is a nasal chemosensory system involved in pheromone detection. The chemosensory receptor neurons are located in the sensory epithelium of the vomeronasal organ (VNO). Their axons terminate in the glomeruli of the accessory olfactory bulb (AOB). In this study, we examined the expression of calbindin D28k (CB) in the rat VNO and AOB. In the VNO, a subpopulation of receptor neurons in the middle layer of the sensory epithelium was immunostained with antibodies to CB. Their axons could be traced to terminate in a group of glomeruli in the anterior half of the AOB glomerular layer. This group of CB-immunostained glomeruli in the anterior half of the AOB included a few large glomeruli close to the boundary between the anterior and posterior halves of the AOB, and several small glomeruli scattered in the anterior region of the AOB glomerular layer. The positions of the CB-immunostained glomeruli in the AOB, especially those close to the anterior-posterior boundary, were similar in the two bulbs and in different rats. No sex difference was found. A developmental study showed that the CB-immunoreactive receptor neurons in the middle layer of the VNO sensory epithelium and CB-immunoreactive glomeruli in the anterior AOB were present on the 14th postnatal day and older. The distribution pattern of the CB-immunostained receptor neurons and their localized projection suggest the possibility that these neurons may express the same or functionally related pheromone receptor genes.     

Microalbuminuria as a predictor of early glomerular injury in children with sickle cell disease

Objective : A cross sectional study was carried out to determine the prevalence of microalbuminuria in the pediatric patients with sickle cell disease.Methods : The study was carried out on 64 pediatric patients aged less than 14 years with documented HbSS, HbAS and HbS beta thalassemia, Microalbuminuria was estimated using single radial immuno diffusion technique. Majority of the study subjects were of HbSS type. 38.5% had symptoms for >2 years. 18.8% of the study population had significant microalbuminuria (19.2% of SS types and 18.8% of Hb AS types).Result : Microalbuminuria excretion was significantly more in patients >9 years of age as compared to young patients (p<0.05). Mean serum creatinine levels did not show any significant difference in the various study groups.Conclusion : Microalbuminuria estimation is a very important clinical marker of preclinical glomerular damage in patients with sickle cell disease. Its estimation would help in the early detection of such patients and prompt initiation of therapy.     

Role of angiotensin II and endogenous vasodilators in the control of glomerular hemodynamics

The balance of vascular tone between afferent (Af-) and efferent arterioles (Ef-Arts) is a crucial determinant of glomerular hemodynamics. Thus, to understand renal physiology and pathophysiology it is important to study the mechanisms that control their vascular resistance. In order to directly study these mechanisms, we have developed several in vitro microperfusion preparations of these arterioles, which have the advantage of allowing us to observe the arteriolar diameter directly in the absence of systemic hemodynamic and hormonal influences. Using these preparations, we have found that angiotensin II (Ang II) causes much stronger constriction in Ef- than in Af-Arts and that this difference is mediated by nitric oxide (NO)- and prostaglandin (PG)-induced modulation of Ang II action in the Af-Art. We have also found that the vasoconstrictor effect of Ang II on Ef-Arts is modulated by PG produced by the upstream glomerulus. Thus, this may be a mechanism whereby the glomerulus controls its own capillary pressure by releasing PG and thereby adjusting the resistance of the downstream Ef-Art. In addition, we have found that in these arterioles activation of the Ang II type 2 (AT₂) receptor causes endothelium-dependent vasodilation, which modulates the vasoconstrictor action mediated by its type 1 (AT₁) receptors. Such modulator mechanisms that regulate Af- and Ef-Art tone may play an important role in the precise control of glomerular hemodynamics, and their alterations may play a role in the pathophysiology of renal diseases, including hypertension. Indeed, we have demonstrated that the vasoconstrictor action of Ang II on the Af-Art is exaggerated in spontaneously hypertensive rats, an animal model of human essential hypertension, due to an impaired function of the AT₂ receptor before the development of hypertension. Because such exaggerated vasoconstriction leads to the elevation of renal vascular resistance (an important pathogenic factor for essential hypertension), our findings suggest that impaired function of the AT₂ receptor in Af-Arts may play a role in the pathophysiology of essential hypertension.     

糖尿病肾小球内非酶糖化与苯那普利的抑制作用及机制

目的　探讨苯那普利对糖尿病肾小球内非酶促糖化反应的作用及机制。方法　以链脲佐菌素诱发的单侧肾切除糖尿病大鼠为模型，检测苯那普利投药４ 周后，糖尿病大鼠血胰岛素水平、肾功能指标、血清及肾小球内糖化产物表达水平的改变。结果　用药的糖尿病大鼠，肾功能指标［ Ｂ Ｕ Ｎ 从（１７３８ ±２２２）ｍ ｍｏｌ／ Ｌ 降至（１２８３ ±２０９）ｍ ｍｏｌ／ Ｌ， Ｐ ＜ ００５］ 、血清糖化蛋白水平［ 果糖胺从（５３０３ ±０１２３）ｍｍｏｌ／ Ｌ降至（２００３ ±０１２５）ｍ ｍｏｌ／ Ｌ， Ｐ ＜ ００５］ 明显下降，肾小球外基质（ Ｅ Ｃ Ｍ） 积聚被抑制，非酶糖化反应程度以及晚期糖化产物（ Ａ Ｇ Ｅｓ） 的蓄积亦有明显改善。血浆游离胰岛素水平升高［ 从（９０２ ±２３４） ｍ Ｕ／ Ｌ 升至（１６７ ±７１３）ｍ Ｕ／ Ｌ， Ｐ＜ ００５］ ，因而高血糖程度稍有改善。结论　苯那普利对糖尿病大鼠肾小球内基质蛋白的非酶糖化有显著的抑制作用，其作用途径与其部分改善胰岛功能、降低血糖或其他不依赖于血糖浓度降低的作用有关     

Morphological complexity of the glomerulus in the rat accessory olfactory bulb-a Golgi study

Using the rapid Golgi method, the accessory olfactory bulb (AOB) of the adult rat was examined. The principal neurons of the AOB were very variable in terms of their dendritic branching pattern and morphology of the glomerular arbors. Some glomerular arbors occupied small portions, other large portions of a single glomerulus. These morphological patterns suggest that complex integrative events occur in the AOB.     

257例弥漫性肾病超声引导下快速自动活检情况分析

目的　分析超声引导下快速自动肾活检的临床应用价值。方法　超声引导下经皮快速自动肾穿刺活检弥漫性肾病患者 2 5 7例 ,所取组织送病理学检查。以检出肾小球作为取材成功 ,明确病理诊断为取材满意。结果　左右肾下极共进针 62 2次 ,获 3 95 2个肾小球 ,平均每例进针 2 .42次 ,取材成功率 97.2 8% ,左肾下极取材成功率略高于右肾下极 ;不同进针次数取材成功率不同 ,且随着进针次数增加 ,取材成功率亦增大 (P <0 .0 5 )。病理类型中以原发性肾小球疾病为多见。结论　超声引导下快速自动肾活检技术是一种安全、高效的微创检查方法 ,值得临床推广应用     

国人肾小球大小正常值测定及测量方法探讨

目的 确定国人肾小球大小正常值并探讨肾小球直径测量法。 方法 选择我科1998至2008年肾穿刺病理检查病例中体质量及血糖正常、病理诊断为肾小球轻微病变或薄基底膜肾病的100例患者作为正常值检测组,在其肾小球最大剖面上用直接及间接两种方法测量毛细血管袢直径。同时随意选择体质量及血糖正常的微小病变肾病、局灶节段性肾小球硬化（FSGS）及膜性肾病患者各10例,进行上述肾小球直径测量,并与正常值检测结果比较。 结果 直接和间接测量法结果一致,性别与年龄对肾小球直径无明显影响。通过不同方法获得的肾小球毛细血管袢直径正常值范围如下：（1）含极（血管极、尿极）肾小球：直接法结果为101.3～182.9 μm;间接法为100.3～181.5 μm;（2）含极肾小球加大于它们的无极肾小球：直接法结果为108.5～182.9 μm;间接法为107.6～183.2 μm。另外,30例肾脏病患者的肾小球直径均在此正常值范围内。 结论 本研究应用的两种肾小球直径检测法均可行,获得的国人肾小球直径正常值范围可以推广。     

Transplantation of postnatal vomeronasal organ in the CNS of newborn rats

The present study was conducted to examine the survival and development of intracerebral transplanted neonatal rat vomeronasal organs (VNs). Complete neonatal (P5–P10) VNs were transplanted into the parietal cortex region of littermates and examined at 10–100 days by light microscopy. The VN survived and was organized into a series of vesicles lined by respiratory and/or sensory epithelia. Sensory neurons grew long axons that fasciculated and invaded the surrounding brain parenchyma. The newly developed axons did not prefer a specific brain region. The axons developed a complex fiber plexus either at the interface between transplant and host tissue or deep within the host brain parenchyma. Vomeronasal axons consistently formed glomerular-like structures within the fiber plexus. Our results suggest that glomerular formation is not dependent on specific target or length of axon development, but rather on a set of complementary axons that display mutual recognition.