The innervation of the ureter in the duck (Anas platyrhynchos). A morphological and quantitative study

The morphology and distribution of the innervation in the duck ureter were studied using AChE histochemistry and PGP 9.5 immunohistochemistry. The density of AChE positive ganglia and neurons was calculated in the adventitial and muscular layers both in young and adult birds. Moreover, in order to investigate regional differences in neuronal density, separate neuron counts and neuron density calculations were performed for the upper, intermediate and lower parts of the ureter, and the data were statistically evaluated. Three nerve plexuses located in the tunica adventitia, in the tunica muscularis and in the lamina propria respectively, were observed. Both in young and adult ducks, the density of adventitial neurons was significantly greater in the lower tract than in the upper and intermediate tracts. The findings of the present study suggest that, in birds, the innervation may play a role in ureteric functions such as epithelial mucosecretion, muscular motility, and closure and/or opening of the ureteric papilla.     

Colonic enteric nervous system in patients with familial amyloidotic neuropathy

The colonic enteric nervous system was investigated in autopsy specimens from 12 patients with familial amyloidotic neuropathy (FAP) and 9 controls. The infiltration of amyloid deposits in the enteric nervous system was studied by double staining for amyloid and nerve elements. The myenteric plexus was immunostained for protein gene product (PGP) 9.5, vasoactive intestinal peptide (VIP), substance P and nitric oxide synthase (NOS). The immunostained nerve elements were quantified by computerised image analysis. Double staining revealed that there was no amyloid infiltration in the ganglia, or in the nerve fibres in the colonic enteric nervous system of FAP patients. The relative volume density of PGP 9.5-immunoreactive nerve fibres in both the circular and the longitudinal muscle layers in FAP patients did not differ significantly from that of controls. The relative volume density of VIP-immunoreactive nerve fibres in the circular muscle layer was significantly decreased in FAP patients compared with controls, but not in the longitudinal layer. The number of VIP-immunoreactive neurons/mm² myenteric ganglia was significantly decreased in FAP patients. There were no statistical differences in the relative volume density for substance P- and NOS-immunoreactive nerve fibres between FAP patients and controls, nor was there any difference between FAP patients and controls regarding the number of NOS- and substance P-immunoreactive neurons/mm² myenteric ganglia. It is concluded that the colonic enteric nervous system as a whole is intact and is not damaged by amyloid infiltration. The present observation of a reduction of VIP-immunoreactive nerve fibres and neurons in myenteric plexus of FAP patients might be one of the factors that contribute to the motility disorders seen in FAP patients. Received: 1 September 1998 / Revised, accepted: 26 November 1998     

Ubiquitin, PGP 9.5 and dense body formation in trimethyltin intoxication: differential neuronal responses to chemically induced cell damage

Ubiquitin in normal cells may be important in degrading or transferring short-lived or aberrant proteins to lysosomal dense bodies. To examine its role in degrading proteins produced by a chemical insult, changes in the distribution of ubiquitin and the carboxy-terminal hydrolase, PGP 9.5, have been studied in rat hippocampal neurons and cerebellar Purkinje cells in trimethyltin intoxication. Here tubulovesicular dense bodies (TVBs) form from 12h onwards associated with vacuolation of the Golgi apparatus. Striking accumulations of lysosomal dense bodies follow in hippocampal pyramidal cells but not in cerebellar Purkinje cells; many of the hippocampal neurons later die, while the Purkinje cells generally survive. Ubiquitin immunoreactivity was diffusely increased in hippocampal pyramidal and Purkinje cells 6 h after dosing. By 12 h both diffuse and granular ubiquitin immunoreactivity was present that intensified over 24 and 48 h. Both by light and electron microscopy TVBs showed ubiquitin immunoreactivity, but dense bodies in hippocampal perikarya did not stain with an anti-ubiquitin antibody. PGP 9.5 immunoreactivity was not altered in hippocampal cells at any time, while Purkinje and Golgi cell dendrites and perikarya showed intensified labelling at 3 h that reached a peak of 12 h. At 48 h Western blot analysis of hippocampal homogenates showed significant increases in high molecular weight (HMW) ubiquitin conjugates, while cerebellar homogenates showed an increase in ubiquitin-histone conjugates. Northern blot analyses showed no change in ubiquitin or PGP9.5 gene expression in hippocampus or cerebellum. These findings suggest that the material in the TVBs in hippocampal cells is not being degraded by the ubiquitin system but passes ubiquitinated into the lysosomal system, while material in Purkinje cell TVBs is degraded by the ubiquitin system, suggesting it may have a different composition in each type of neuron.     

Growth-associated protein-43 immunohistochemical and ultrastructural changes in jaw muscle spindles of the rat following loss of occlusion

The effects of complete loss of occlusion on the structural and functional status of these muscle spindles were investigated by immunohistochemistry either for protein gene product 9.5 (PGP 9.5) or growth-associated protein-43 (GAP-43) by light and electron microscopy. All the upper molars of 4-week-old Wistar rats were extracted and the erupted portions of the upper and lower incisors of the same animals were cut-off at the level of the interdental papilla every other day. In a control group, immunoreactivity for GAP-43 was positive in the developing annulospiral endings of 2-week-old rats, but was not detected in any of the muscle spindles after 3 weeks of age. At 4 weeks of age, the PGP 9.5 immunostained spindles had well-differentiated annulospiral endings. Ultrastructurally, these afferent endings showed lenticular or circular profiles in cross-sections, and were differentially indented into the intrafusal-fibres. The inner surfaces of the terminals formed rather smooth myoneural junctions, while the outer surfaces were covered only by basal lamina continuous with that of the underlying intrafusal muscle fibres. After the experimental elimination of occlusal contact, GAP-43 immunoreactivity reappeared in some nerve endings of muscle spindles by 3 days, and persisted for at least 28 days. During this period, the afferent-terminals exhibited various fine structural abnormalities such as irregular outlines and invaginated neuromuscular interfaces. Some sensory-terminal (ST) profiles were completely engulfed by intrafusal-fibres. However, GAP-43 expression and ultrastructural alterations became undetectable within a week of the end of incisal cutting and the recovery of incisal-contact. These data indicate that remodelling of nerve terminals in muscle spindles, as assessed by GAP-43 expression and ultrastructural changes, occurs soon after a loss of occlusion, and ceases if incisal-contact is restored. It is concluded that possible changes in jaw muscle function, as well as a sudden loss of proprioceptive sensory input from the periodontal mechanoreceptors of molars and incisors, induce the structural reorganisation of nerve terminations in jaw muscle spindles that is associated with the appearance and disappearance of GAP-43 immunoreactivity.     

Evaluation of endoscopic approaches for deep gastric-muscle-wall biopsies: what works?

BACKGROUND: A major barrier to furthering our understanding of the pathophysiology of neuromuscular GI diseases, including functional GI disorders, is the inability to obtain deep gastric-wall biopsy specimens that include both layers of the muscularis propria, which allows evaluation of specific cell types, including myenteric ganglia. OBJECTIVES: The aims of this preclinical study were to (1) evaluate different endoscopic approaches for obtaining deep gastric-muscle-wall biopsy specimens and (2) determine if myenteric ganglia were present in the tissue samples. DESIGN AND INTERVENTIONS: This was a preclinical acute study by using a pig model. Multiple samples were obtained from 4 pigs. The endoscopic techniques evaluated were (1) EUS-guided tru-cut biopsy of the gastric wall, (2) jumbo biopsy of the post-EMR site, (3) jumbo biopsy of the gastrotomy margin, (4) serosal-side biopsy through a gastrotomy, and (5) double-EMR resection. MAIN OUTCOME MEASUREMENTS: Resected tissue was submitted for histology to determine which wall layers were included in the resected specimen. Hematoxylin and eosin staining was used to determine which muscle layers were biopsied, and an antibody to protein gene product 9.5 was used to determine if myenteric ganglia were present in the sample. RESULTS: Seventy-two tissue samples were obtained: EUS-guided tru-cut biopsy (n=16), jumbo biopsy of the post-EMR site (n=16), jumbo biopsy of the gastrotomy (n=16), serosal-side biopsy (n=16), and double-EMR resection (n=8). Only the double-EMR resection tissues showed the presence of longitudinal muscle, indicating the presence of both muscle layers and the myenteric plexus. Immunofluorescence studies demonstrated the presence of myenteric ganglia only in the double-EMR tissues and in none of the other gastric samples. No adjacent organs were included in the resection. CONCLUSIONS: The double-EMR technique was the only studied technique that resulted in a deep gastric-wall sample and provided sufficient tissue to evaluate both muscle layers and the intermuscular layer that contain myenteric ganglia. Further studies are needed to verify the efficacy and to assess the safety of this approach.     

蛋白基因产物9·5和泛素在IgA肾病中的表达

目的观察蛋白基因产物9·5(PGP9·5)和泛素(ubiquitin)在IgA肾病(IgAN)患者肾组织的表达及其与临床病理的关系,探讨其在IgAN病变的作用。方法 53例IgAN患者分为单纯血尿组(A组)及混合蛋白尿、血尿组(B组),免疫组织化学和免疫双染色法观察PGP9·5和泛素在IgAN肾组织中的表达。结果免疫组织化学显示在IgAN肾组织中,PGP9·5和泛素均有表达,主要在上皮细胞(壁上皮细胞、特别是小管上皮细胞)及新月体表达。免疫组化双染色显示:泛素分布更广泛,PGP9·5表达比泛素表达稍强,按Lee氏分级的级别增加逐渐增高,免疫组织化学半定量评分显示增生肥厚病变部位及新月体表达明显强于正常和纤维化/萎缩的部位(P<0·01),PGP9·5及泛素的表达与患者24h尿蛋白定量及病理分级成正相关。结论 PGP9·5及泛素可能在IgAN病变及进展中发挥了重要作用。     

呼吸道合胞病毒感染对豚鼠咳嗽相关气道功能及其神经递质的影响

目的 观察呼吸道合胞病毒RSV(感染)对豚鼠咳嗽相关的气道功能及神经递质的影响,探讨病毒感染后咳嗽的发病机制.方法 雄性SPF级豚鼠60只,按数字随机法随机分成正常对照组、病毒感染组和哮喘组,病毒感染组按病毒感染后天数分为6、12、28和42 d四个组,每组10只.通过滴鼻方法接种RSV.Buxco肺功能仪测定咳嗽反射...     

Role of tumor vascular architecture in drug delivery

Tumor targeted drug delivery has the potential to improve cancer care by reducing non-target toxicities and increasing the efficacy of a drug. Tumor targeted delivery of a drug from the systemic circulation, however, requires a thorough understanding of tumor pathophysiology. A growing or receding (under the impact of therapy) tumor represents a dynamic environment with changes in its angiogenic status, cell mass, and extracellular matrix composition. An appreciation of the salient characteristics of tumor vascular architecture and the unique biochemical markers that may be used for targeting drug therapy is important to overcome barriers to tumor drug therapy and to facilitate targeted drug delivery. This review discusses the unique aspects of tumor vascular architecture that need to be overcome or exploited for tumor targeted drug delivery.