rt—PA在血脑屏障氧糖剥夺体外模型中对神经细胞保护的研究

目的观察重组组织型纤溶酶原激活剂（rt—PA）在体外血脑屏障氧糖剥夺模型中对神经细胞的影响,探讨rt—PA对脑缺血神经元的保护作用。方法利用Transwell培养小室为支架,构成以人血管上皮细胞为基础的体外血脑屏障模型;利用厌氧培养箱及无糖培养液,建立体外缺血缺氧模型;在体外缺血缺氧模型基础上,采用组织培养技术,培养神经细胞,并在缺血缺氧条件下,使用MTT法进行检测不同剂量rt—PA对神经细胞活性的影响。结果分别在氧糖剥夺实验（OGD）及非0GD条件下,在不同rt—PA药物的浓度作用下,低浓度（0．3125ug／mL）对非0GD条件下神经细胞的生长有促进作用,在OGD条件下,低浓度（0．625ug／mL,0．3125gg／mL）对神经细胞同样具有保护作用。结论rt—PA可能对脑缺血后神经细胞存在保护作用,并与rt—PA的剂量相关,在0GD条件下,低剂量rt—PA对神经细胞的保护作用更为显著。     

Changes of blood humoral substances in experimental cirrhosis and their effects on portal hemodynamics

The changes of humoral substances in the blood of cirrhotic rats were studied together with their effects on portal hemodynamics at different stages during the development of cirrhosis. The profiles of humoral substances and hemodynamics in two different cirrhotic rat models were also investigated. During the development of cirrhosis, glucagon increased markedly in all stages, histamine and vasoactive intestinal polypeptide (VIP) increased in the early stage, serotonin (5-HT) and somatostatin (SS) increased in the middle and late stages. There were different patterns of humoral substances in different cirrhotic models. Glucagon was the main humoral substance elevated in CCL4 induced cirrhosis, but histamine and 5-HT were mainly elevated in the blood in thioacetamide (TAA) induced cirrhosis. The hemodynamics altered differently in different stages during the development of cirrhosis and differently in the two cirrhotic rat models. Exchange transfusions between normal and cirrhotic rats resulted in an elevation of portal flow in normal rats, but no such changes were found after exchange pressure and an increase of portal blood transfusions between normal rats. The relationship between the humoral substances and portal hemodynamics is discussed. The results of this study strongly support the hypothesis of "humoral mechanism" in the pathogenesis of portal hypertension due to cirrhosis.

     

非酒精性脂肪肝肝纤维化指标与中医证型的关系

目的：探讨非酒精性脂肪肝肝纤维化指标与中医证型的关系，为中医辨证提供有益参数。方法：符合B超诊断的非酒精性脂肪肝患者（79例），经中医辨证后作肝纤维化指标检测，并以不嗜酒的健康人作为对照。结果：脂肪肝组肝纤维化指标明显高于对照组（P＜0．05，P＜0．01）；各证型间，痰瘀互结型Ⅲ型前胶原（PCⅢ）、Ⅳ型胶原（CⅣ）、层粘连蛋白（LN）明显高于脾虚痰湿、湿热内蕴两型（P＜0．05，P＜0．01），而透明质酸（HA）无明显差异（P＞0．05）。结论：脂肪肝患者存在不同程度的肝纤维化趋向，提示痰瘀互结可能是非酒精性脂肪肝肝纤维化指标升高的中医主要病理因素。     

Symptomatic and pathophysiological observations in a modified animal model of allergic rhinitis

There are many animal models for studying allergic rhinitis. However, they either need a too long establishment period or fail to show significant late allergic responses. In the model described in this paper, guinea pigs were sensitized and challenged intranasally with ovalbumin according to a modified protocol. As controls, antihistamine-treatment and non-sensitized, non-treatment groups were studied in parallel. Early and late symptoms, passive cutaneous anaphylaxis (PCA) reaction, nitric oxide synthase (NOS) immunoreactivities, pathological changes in nasal mucosa and nasal lavage fluid (NLF), and histamine, TXB2 and p-LTs levels in NLF were evaluated. In contrast to the control groups, the model group exhibited typical symptoms, including late phase nasal blockage, and increased levels of IgG1 and IgE. Considerable eosinophil infiltration and eNOS immunoreactivities in nasal mucosa, and increased levels of histamine, TXB2 and p-LTs in NLF were also observed. This model was not only capable of showing satisfactory symptomatic and pathophysiological changes in allergic rhinitis but also showed good responses to antihistamine treatment. The model can be established in six weeks. For the first time, respiratory rate was employed as an index to reflect the nasal blockage of guinea pigs and it proved to be a reliable indicator.     

CO2 laser cordectomy as a day-case procedure

OBJECTIVE: To evaluate the safety of CO2 laser cordectomy in the treatment of glottic carcinoma as a day-case procedure. STUDY DESIGN: This was a retrospective study of a cohort of 73 patients with glottic carcinoma treated by laser cordectomy as a day-case procedure using a CO2 laser, between January 2000 and June 2004. RESULTS: There were no major complications and no patients required reintubation. More than 90 per cent of the patients were discharged on the day of the procedure. There were seven unplanned admissions to hospital but none of these appeared to be the direct result of the surgery, and the patients were discharged the next day. All the patients stated they would have further surgery in this manner if required. CONCLUSION: Laser cordectomy for glottic carcinoma can be safely performed as an out-patient procedure if patients are carefully selected according to specific criteria.     

Detection of the sentinal node in squamous-cell carcinoma of the oral cavity and oropharynx. Preliminary study

INTRODUCTION: The sentinel lymph node is defined as the first relay of the lymphatic drainage of the tumor. Isotopic detection of the sentinel lymph node and absence of its metastatic invasion should theoretically be predictive of total drainage of the tumor. The goal of this study was to evaluate sentinel lymph node detectability by lymphoscintigraphy in N0 and/or N1 squamous-cell carcinoma of oral cavity and oropharynx and to determine its negative predictive value. MATERIAL AND METHOD: Lymphoscintigraphy was used for sentinel lymph node detection. The procedure required peritumoral injection of technicium-labeled colloids to enable anatomical and cutaneous location of the sentinel lymph node. A one-way Tyco-Mallinckrodt probe was used for intraoperative detection of the sentinel lymph node. This prospective study included 21 patients with N0 or N1 squamous-cell carcinoma of the oral cavity and the oropharynx. The surgical attitude based on T and N was not modified in this prospective study without direct individual benefit for the patient. Neck dissection was achieved without difficulty. RESULTS: The sentinel lymph node was identified in 20 out of 21 subjects. The sentinel lymph node was not identified in one patient with recurrence T2N0M0 squamous-cell carcinoma of the oropharynx radiated 3 years earlier. The percentage of false-negatives was 12.5% (1 false-negative out of 8 positive patients), giving a sensibility of the detection method of 87.5% (IC (95%)=[47.35-99.68]). This false-negative patient had a T3N0M0 squamous-cell carcinoma of the oropharynx with a sentinel lymph node removed in territory III. Neck dissection revealed 1 N + R- in the sub-mandibular territory associated with 27 N-R-. The probability of not finding a metastatic node at neck dissection when the sentinel lymph node is not metastatic (negative predictive value) was 92.3% (12/13) (IC (95)=[63.97-99.81]). The specificity of the method was 100%, as was the positive predictive value, because no sentinel node was diagnosed positive wrongly on frozen sections among patients without true histological node metastasis. DISCUSSION: For routine care of patients with squamous-cell carcinoma of the oral cavity and the oropharynx detection of the sentinel lymph node is proposed primarily for patients with T1T2N0 staging. Larger tumors can modify the architecture and flow within the lymphatic ducts, and consequently even the concept of a sentinel lymph node. Systematic neck dissection is required or T3T4, even when N0. Our series of T1T2N0 tumors is too small to enable statistically significant conclusions. A low level of false-negative in a larger series would be necessary to propose this technique instead of convention neck dissection for T1T2 tumors of the oral cavity and oropharynx.     

PERIPHERAL AND AUTONOMIC NERVE FUNCTION. TESTS IN EARLY DIAGNOSIS OF DIABETIC NEUROPATHY CORRELATION BETWEEN MOTOR NERVE CONDUCTION VELO- CITY AND FASTING PLASMA GLUCOSE

This paper reports the application of peri- pheral motor ne'rve conduction velocity (MNCV) determination and 6 noninvasive autonomic functional tests for the early diagnosis of dia- betic neuropathy. Among the 150 cases of new- ly discovered diabetics investigated during ex- tensive survey in Sha.nghai, 135 cases of tlia.- betic neuropathy were diagnosed. In this group, patients with both neurologic symptoms and signs were found in 56 cases, only symptoms with no signs in 50, only sign.s with no symp- toms in 8 and both symptoms and signs absent but diagnosis. based on special tests in 21. The motor nerve conduction velocity of the median n., ulnar n., and fibular n. were ascer- tained on JD Type II electromyography. The velocity was found to be significantly slower in diabetics with neuropathy than the control group. H-reflex and tibial n. Iatency were found to be prolonged in diabetics as compared with the control group. There is negative cor- relation 'oetween the MNCV and fa.sting plas- ma glucose and positive correla.tion between the H-reflex and fasting plasma glucose, indicating that hyperglycemia may be closely related to the pathogenesis of diabetic neuropathy. No correlation was found between the MNCV, age and duration of d[iabetes. For early diagno,sis of diabetic neuropathy, besides the symptoms and signs, motor nerve conduction velocity and 4 0f the 6 noninvasive autonomic ne'rve function test are valuable and reliable diagnostic procetlures. Differential diagnosis from other causes of neuropathy is also emphasized.     

Effects of prolonged light exposure, GABA, and glycine on horizontal cell responses in tiger salamander retina

1. The effects of prolonged light exposure, gamma-aminobutyric acid (GABA), and glycine on the horizontal cell (HC) light responses were studied in the superfused flat-mounted isolated retinas of the larval tiger salamander. 2. Under prolonged dark-adapted conditions, the time-to-peak of the HC light response was approximately 2-4 s, and after the termination of prolonged (6-8 min) light exposure, the time-to-peak became approximately 0.5-1 s. 3. This prolonged light-induced change in response rise time was not observed in either photoreceptors or bipolar cells, and thus the change in HC response rise time may occur postsynaptically in the HC membrane. 4. Application of 100 microM of GABA mimicked prolonged darkness and reversibly slowed down the HC response rise time, and application of 100 microM bicuculline mimicked prolonged light exposure and reversibly sped up the HC response rise time. 5. Glycine also slowed down the HC response rise course, but its effect was not observable until the concentration was raised to 1-3 mM. Strychnine did not exert any effect on HC responses when applied alone, but it could reverse the glycine actions. 6. The actions of glycine disappeared in the presence of bicuculline, indicating that the GABA and glycine pathways were probably not independent. Application of 5-10 mM glycine produced an increase of flow of preloaded 3H-GABA from the retina. 7. These results indicate that GABA may be the primary modulator that slows down the kinetics of the postsynaptic membrane proteins in the HCs. The extracellular concentration of GABA is probably high in prolonged darkness, and it is low after prolonged light exposure. Glycine, when applied at high dose, results in an increase of GABA release that slows down the HC response time course. 8. Prolonged darkness and light exposure appear to modulate the HC response in the time domain through GABA, and this change in HC response time course is probably responsible for shaping the bipolar cell responses and making the retinal signals more transient under light-adapted conditions.