C-terminal tail of β-adrenergic receptors: immunocytochemical localization within astrocytes and their relation to catecholaminergic neurons in N. tractus solitarii and area postrema

β-Adrenergic receptors (βAR) in the medial nuclei of tractus solitarii (m-NTS) and area postrema (AP) may bind to catecholamines released from neurons, whereas only the AP has fenestrated capillaries allowing access to circulating catecholamines. Since varied autonomic responses are seen following βAR activation of the dorsal vagal complex, including the m-NTS and AP, we hypothesized that there might be a cellular basis for varied responses to βAR stimulation that depends pn the differential access to circulating catecholamines. Therefore, we comparatively examined the ultrastructural localization of the βAR in relation to catecholaminergic neurons in these regions. An antibody directed against the C-terminal tail (amino acids 404–418) of hamster β-adrenergic receptor (βAR404) was used in this study. The localization of βAR404 was achieved by the avidin-biotin peroxidase complex (ABC) technique in combination with a pre-embed immunogold labeling method to localize tyrosine hydroxylase (TH), the catecholamine-synthesizing enzyme. Within m-NTS and at subpostremal border, labeling for βAR404 was evident along the intracellular surface of plasma membranes of small, apparently distal, astrocytic processes. Astrocytic processes with βAR404-immunoreactivity formed multiple, thin lamellae around TH-labeled and non-TH neuronal cell bodies and dendrites. βAR404-immunoreactive astrocytes also extended end-feet around blood vessels and surrounded groups of axon terminals that were directly juxtaposed to each other. Some, but not all, of these axons demonstrated TH-immunoreactivity. Fewer βAR404-immunoreactive astrocytes were detected in AP, regardless of their proximity to catecholaminergic processes or blood vessels. The present astrocytic localization of βAR404, together with the earlier, neuronal localization of βAR's third intracellular loop, suggest that the βAR may be substantially different between neurons and astrocytes. The regional difference in the prevalence of βAR404-immunoreactive astrocytes suggests that these receptive sites may either: (i) be preferentially activated by catecholamines released from terminals rather than circulating catecholamines; or (ii) be down-regulated in AP due to blood-born substances, such as catecholamines. The extensive localization of βAR in the border between m-NTS and AP also suggests that catecholaminergic activation of these astrocytes may dictate the degree of diffusion of catecholamines which are of neuronal or vascular origin. The specific localization of βAR404-immunoreactivity to the more distal portions of astrocytes suggests the possibility that astrocytes have restrictive distributions of βAR and that the β-adrenergic activation lead to morphological or chemical changes that are also localized to the distal portions of astrocytes. Additionally, the detection of βAR404 in astrocytes contacting non-TH-immunoreactive neurons suggests the possibility for catecholaminergic modulation of non-catecholaminergic neurons via the activation of astrocytes.     

SCHWANN CELLS AND THE REGROWTH OF AXONS IN THE MAMMALIAN CNS: A REVIEW OF TRANSPLANTATION STUDIES IN THE RAT VISUAL SYSTEM

1. We have used peripheral nerve transplants or cultured Schwann cells grafted in association with different types of polymer to study axonal regrowth in the rat visual system. In some instances the glia were co-grafted with fetal tectal tissue. 2. The studies have two main aims: (i) to determine whether retinal axons can be induced to regrow at a site distant from their cell soma, that is, after damage to the brachial region of the optic tract; (ii) to determine whether retinal axons exposed to Schwann cells retain the ability to recognize their appropriate target neurons in CNS tissue. 3. In brachial lesion studies, Schwann cells were placed in the lesion site in association with nitrocellulose papers, within polycarbonate tubes in the presence or absence of a supporting extracellular matrix (ECM), or within polymer hydrogel scaffolds. Autologous sciatic nerve grafts were also used. Immuno-histochemical studies revealed the presence of regenerating axons within all polymer bridges. Regrowth of retinal axons was also seen, however, growth was not extensive and was limited to the proximal 1–1.5 mm of the implants. 4. In target innervation experiments, two surgical paradigms were developed. In one experiment, a segment of sciatic nerve was autografted onto the transected optic nerve in adult rats and the distal end of each graft was placed adjacent to fetal tectal (target) tissue implanted into the frontal cortex. To date, we have not been able to demonstrate selective recognition of target regions within tectal transplants by retinal axons exiting the sciatic nerve implants. 5. In the second experiment, Schwann cells were mixed with fetal tectal cells and co-grafted to the midbrain of newborn host rats. Schwann cells altered the characteristic pattern of host retinal growth into tectal grafts; in some cases axons were induced to grow away from appropriate target areas by nearby co-grafted Schwann cells. 6. In summary, Schwann cell/polymer scaffolds may provide a useful way of promoting the regrowth of damaged axons in the CNS, however: (i) in adults, at least, their effectiveness is reduced if they are located at a distance from the cell bodies giving rise to regenerating axons; (ii) in some circumstances exposure to a peripheral glial environment may affect the capacity of regenerating axons to recognize appropriate target cells in the CNS neuropil.     

内镜下应用保护性套管取上消化道异物

食管、胃异物经内镜取出是目前认可的方法 ,成功率约90 % [1 ] 。但是对部分异物特别是细长锐利性异物取出时 ,易有出血、穿孔合并症 ,且极易伤及食道及咽喉部黏膜 ,甚至出现黏膜撕裂、剥脱及引起嵌顿等严重并发症。大连医科大学第二临床学院消化内科 1 995年 1月～ 2 0 0 3年 5月应用食管保护性套管成功取出食管及胃细长锐利性异物 6 9例 ,无 1例异物造成继发性食管黏膜损伤发生。现报告如下。1　材料和方法1 .1　一般资料①本组 6 9例患者。男 4 2例 ,女 2 7例 ;年龄 2 2岁～ 92岁。误服异物史 :30min～ 7d。②异物种类 :缝被针、铁钉、铁…     

泌尿系感染者病原菌及耐药性分析

目的：了解近年来泌尿系细菌感染致病菌及耐药性，为合理应用抗生素，提供临床根据。方法：对泌尿系感染患者298株病原菌进行药物敏感试验。结果：大肠埃希菌仍是引发泌尿系感染的主要病原菌，占53％，其次是葡萄球菌属，占19．40％，肠杆菌属占10．06％，肠球菌属占4．70％等，各类菌属耐药情况。结论：临床医师必须关注本地病原菌分布及耐药情况，合理应用抗生素，减少耐药性播散。     

可控盲结肠膀胱术19例

目的 :探讨膀胱全切术后可控盲结肠膀胱术的选择及应用。方法 :回顾性分析我科 1 9例可控盲结肠膀胱术患者的临床资料。结果 :1 9例患者术后恢复较好 ,储尿囊平均容量 4 80ml,平均压力 (1 .96± 0 .4 9)kPa ,排尿控制较好 ,插管容易 ,无尿失禁及输尿管反流。结论 :可控盲结肠膀胱术具高容量、低内压、控制排尿等特点 ,可极大提高患者的生活质量 ,其中以可控去带盲结肠膀胱术最为简单、有效 ,值得临床应用     

The epidemiology of urinary dysfunction in Chinese women

The epidemiology of urinary dysfunction in a Chinese population living in Hong Kong was investigated. Fifteen hundred ethnic Chinese women answered a telephone questionnaire including symptoms of urinary dysfunction, anthropometric measurements, obstetric history and place of birth. The relative predictive value of these factors was analyzed using logistic regression. The prevalence of urinary dysfunction was 13%. Ten percent reported stress incontinence, and 4% had urgency or urge incontinence. The strongest predictor was place of birth, with women born in mainland China having the highest prevalence of pure stress incontinence (OR 1.33, CI 1.1–1.6). For the symptoms of detrusor instability age was the strongest predictor, with women over 50 years being at greater risk (OR 2.8, CI 1.6–5.0). Contrary to earlier beliefs, urinary dysfunction in Chinese women is as common as in Caucasian women. Place of birth is the strongest predictor for pure stress incontinence, with women born in mainland China being at greater risk. This suggests that environmental factors in early life have a differential effect on the development of urinary incontinence. EDITORIAL COMMENT: Taiwan Chinese women have a comparable prevalence of urinary dysfunction with Hong Kong Chinese women. A survey representing a multistage sample of 82 678 women aged 18 years or older was conducted in the Taipei area from January to June 1993. A total of 818 cases were interviewed by trained students. One hundred and eighty-nine (23.1%) of the respondents reported having had some degree of incontinence in the preceding 12 months, 28 (3.4%) reporting regular incontinence. Most presented with stress urinary incontinence, whereas urge incontinence and mixed incontinence were more commonly seen in the elderly group (aged 60 years or older). The risk factors for urinary incontinence included age, number of vaginal deliveries (>3), number of abortions (>2) and maternal history of incontinence. Voiding symptoms (irritative or obstructive) and constipation were significantly more prevalent among respondents with incontinence than those without (P<0.001). This evidence also indicates that the long-held belief that Chinese women have a much lower prevalence of urinary dysfunction than western women has all but ended.     

阿奇霉素和鱼腥草治疗小儿下呼吸道感染

目的　探讨静脉点滴阿奇霉素和鱼腥草治疗小儿下呼吸道感染的临床疗效及其安全性。方法　采用随机对照分组研究 ,观察组使用阿奇霉素 5～ 10mg/kg ,每日 1次 ,加鱼腥草 1～ 3ml/ (kg·d) ,每日 1次静脉滴注 ,疗程 5～ 7d。对照组选用头孢拉定 5 0～ 10 0mg/ (kg·d)加利巴韦林 10mg/ (kg·d)静脉滴注 ,每日 2次 ,疗程 5～ 7d。结果　观察组痊愈率和有效率分别为 72 .5 %和 89.8% ,而对照组的痊愈率和有效率分别为 4 5 .3%和 73.6 % (P <0 .0 1) ,观察组和对照组的不良反应发生率分别为 13.5 %和 10 .8% (P >0 .0 5 )。结论　阿奇霉素加鱼腥草静脉滴注治疗小儿下呼吸道感染临床疗效确切 ,不良反应较少     

Epidemiology of gastro-intestinal and respiratory tract diseases in rural areas of Varanasi (India)

The pattern of gastro-intestinal (GIT) and Respiratory tract (RTI) diseases in rural areas of the Varanasi district, U.P. (India) was studied from the outpatient (OPD) attendance between July 1985 to June 1986. Out of a total of new patients, 19.71% had respiratory diseases in contrast to 27.9% with GIT disease. A decreasing trend was observed in attendance rates as age advanced. The difference in age distribution of males and females was statistically significant. The attendance rates for GIT diseases were higher in female (29.16%) than in males (25.16%) whereas in RTI, the rates were higher in males (19.39%) than in females (18.77%). The attendance rate was found to be higher in rainy season (23.59%) followed by summer (14.50%). Diarrhoea (15.44%) and upper (URTI) respiratory tract infection (19.93%) occupied the major recorded episodes.     

Is it time to reconsider initial antibiotic treatment strategies for severe urinary tract infections in Europe?

Until recently, most reported cases of bacteraemia caused by multidrug-resistant strains of Enterobacteriacae producing an extended-spectrum beta-lactamase (ESBL) in Europe have been nosocomial in origin. However, increasing numbers of reports of community-acquired bacteraemia and urinary tract infection caused by ESBL-producing microorganisms suggest that the geographical origin of patients should be taken into account as a risk-factor for possible ESBL production. Early identification of patients at high-risk of infection with ESBL-producing microorganisms, based on their geographical origin and travel history, should help to optimise initial antibiotic treatment strategies for severe urinary tract infections in Europe.     

钬激光腔内治疗泌尿系结石(附126例报告)

目的：探讨泌尿系结石腔内钬激光治疗效果及安全性。方法：总结钬激光结合腔内泌尿外科技术治疗126例泌尿系结石的临床资料。结果：5例肾结石和11例膀胱结石，均一次碎石成功，109例输尿管结石，单次碎石率为96.3%(105/109)，复杂结石1例数次行输尿管腔镜下碎石。平均结石排净时间2.8周，平均手术时间30min，平均术后住院2d。术中除1例输尿管穿孔外，无其他并发症。结论：钬激光结合腔内泌尿外科技术治疗泌尿系结石，是一种较新的、安全的、有效的方法。