实验性2型糖尿病大鼠模型的建立和评价(Ⅰ)——体重、血糖和肝糖原的变化

目的：用高脂饲料加小剂量STZ腹腔注射建立实验性2型糖尿病大鼠模型。方法：采用Wistar大鼠,分为正常对照组、高脂饲料组、小剂量STZ组（30 mg/kg）和高脂饲料加小剂量STZ（30 mg/kg）组,每10 d测定大鼠体重、空腹血糖和肝糖原等指标,连续50 d,对各组大鼠上述指标进行比较和评价。结果：①体重：高脂饲料组大鼠体重呈连续上升趋势,小剂量STZ组和高脂饲料加小剂量STZ组大鼠体重呈先降低再恢复的趋势;②空腹血糖：高脂饲料组大鼠空腹血糖轻微升高,小剂量STZ组大鼠空腹血糖呈上升的趋势,高脂饲料加小剂量STZ组大鼠空腹血糖呈明显上升趋势;③肝糖原：高脂饲料组大鼠肝糖原明显升高,小剂量STZ组、高脂饲料加小剂量STZ组大鼠肝糖原未见明显改变;结论：高脂饲料加小剂量STZ腹腔注射能成功诱导2型糖尿病大鼠模型,这种造模方法具有成模后血糖维持在较高水平、自身缓解较少、症状较轻和动物状态良好等优点。     

Glial localization of four‐repeat tau in atypical progressive supranuclear palsy

In the present case, a patient in whom limb apraxia and asymmetrical parkinsonism developed suggesting corticobasal degeneration, is reported. Neuropathologic examination revealed numerous tufted astrocytes in the precentral cortex in addition to the characteristic pathologic findings of PSP. Therefore, on the basis of clinicopathologic features, atypical progressive supranuclear palsy was diagnosed. In addition, the brain tissue of the present patient was investigated with an antibody specific for four‐repeat tau (4R‐tau). In the precentral cortex, numerous tau‐positive tufted astrocytes, pretangles, and threads were positive for 4R‐tau. Using a confocal microscopy we demonstrated that tufted astrocytes positive for 4R‐tau were adjacent to astrocytes positive for GFAP. The present findings suggest that accumulation of four‐repeat tau in astrocytes is a degenerative process rather than a reactive process.     

Leukaemia Inhibitory Factor or Related Factors Promote the Differentiation of Neuronal and Astrocytic Precursors within the Developing Murine Spinal Cord

Previously we have shown that leukaemia inhibitory factor (LIF) potentiates the development of murine spinal cord neurons in vitro , suggesting that it, or related factors, may play an important regulatory role in neuronal development. We have further investigated this role and show here that the generation of neurons in cultures of embryonic day 10 spinal cord cells is inhibited by antibodies to the β subunit of the LIF receptor. Since there are more undifferentiated precursors in antibody-treated cultures than in control and LIF-treated cultures, it is concluded that the primary action of LIF, or related molecules, is to promote neuronal differentiation, not precursor survival. In addition, the failure of LIF to support neuronal survival in the period immediately following differentiation suggests that the increased numbers of neurons generated with LIF are not attributable to its neurotrophic action. By selecting neuronal precursors on the basis of their inability to express class I major histocompatibility complex molecules, it was shown that LIF acted directly upon these cells and not via an intermediary cell. LIF also appears to be involved in regulating the differentiation of astrocytes, since it increases the number of glial fibrillary protein (GFAP)-positive cells present in the cultures and since the spontaneous production of GFAP-positive cells is blocked by antibodies to the LIF β receptor. These findings suggest that LIF or related factors promote the differentiation of neural precursors in the spinal cord, but that they are not involved in preferentially promoting precursors down a specific differentiation pathway.     

Polymorphism analysis of four canine MHC class I genes

Abstract: We have studied the variability of four structurally complete dog leukocyte antigen (DLA) class I genes, termed DLA-12, -88, -79 and -64, in a population of mixed breed, unrelated dogs. The human HLA and canine DLA loci share a high degree of similarity in terms of gene structure. This analysis focused on the first three exons of each of four complete canine genes. Exons two and three are the major source of polymorphism in the corresponding human genes. In this analysis, DLA-88 was found to be significantly more polymorphic than the other three genes, with 44 distinct alleles observed among 63 mixed breed, unrelated dogs. The remaining genes had between one and four alleles when examined in 25 dogs. This work was carried out as part of an effort to develop an MHC typing system for the dog, which is critical to the further development of preclinical studies of hematopoietic stem cell and solid organ transplantation in the canine model.     

End-to-side anastomosis of rat carotid artery: comparison of different types of section and shape of the terminal end

Summary In 50 rats, different types of end-to-side carotid artery anastomoses were compared. In one technique, a longitudinal split in the long axis of the vessel was performed to enhance the diameter of the anastomosis. This theoretical advantage was not confirmed in this series. The clamping time, anastomoses time, and tamponade time were increased significantly when compared with a simple, slightly oblique end-to-side anastomosis. This study highlighted that the most simple type of end-to-side anastomosis gave less bleeding, achieved a quicker water-tight anastomosis and decreased the risk of late problems.     

Pharmacological properties of the norepinephrine-induced depolarization of astrocytes in primary culture: evidence for the involvement of an α1-adrenergic receptor

The membrane potentials of astrocytes in primary cultures prepared from neonatal rat cerebral cortices were depolarized by (−)-norepinephrine. The average first response to 10⁻⁵ M (−)-norepinephrine was 24 mV from an average resting potential of −68 mV, and the average for the second response was 14 mV. Thus this process showed marked desensitization. The response was attributed to an activation of an α₁-receptor since it was about 1000 times more sensitive to inhibition by prazosin than to yohimbine or idazoxan. In addition, depolarization was seen to the application of 10⁻⁵ M phenylephrine.     

Extensive replacement of the aorta from the ascending aorta to the supraceliac abdominal aorta during a one-stage operation

A successful replacement of the aorta from the ascending aorta to the supraceliac abdominal aorta in one operation is herein reported. The patient was 66-year-old woman who had DeBakey type I chronic aortic dissection with a pre-disseminated intravascular coagulation (DIC) condition. The image diagnosis revealed a markedly enlarged false lumen with a narrow true lumen in the ascending aorta extending to the diaphragm level while below the diaphragm level, the aortic dilatation was mild. The operation was performed through both a thoracoabdominal incision and a median sternotomy to expose the whole thoracic aorta, and the aorta was replaced from the ascending aorta to the supraceliac abdominal aorta. Selective cerebral perfusion was used for cerebral protection and this was a useful adjunct since no time limitations were thus required during repair of the aortic arch. Although the patient developed several complications postoperatively, she eventually recovered and was discharged from the hospital without any neurological disorders.     

2型糖尿病患者高危因素分析

目的 分析2型糖尿病患者各种高危险因素控制状况及其与慢性并发症的关系。方法 记录464例50岁以上的2型糖尿病患者收缩压、舒张压、血脂、糖化血红蛋白和体质指数，按有无并发症分为两组进行分析。结果 有并发症组糖尿病病程、血压、总胆固醇、低密度脂蛋白胆固醇和血纤维蛋白原明显增高。Wald卡方分析显示糖尿病病程和收缩压有统计学意义。多数患者这些危险因素未得到很好的控制。结论 糖尿病患者存在着多种高危因素，有慢性并发症者更为严重，应注意综合治疗。     

Comparison of [I]metaiodobenzylguanidine kinetics with heart rate variability and plasma norepinephrine level

Background. [¹²³I]Metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. We evaluated the clinical significance of myocardial MIBG imaging as a measure of cardiac sympathetic nervous system function by comparing it to heart rate variability and plasma norepinephrine level.Methods and Results. In 211 subjects, we analyzed heart rate variability with 24-hour electrocardiography, performed scintigraphy with MIBG, and measured plasma norepinephrine levels. Time and frequency domain measures of heart rate variability were calculated with the Marquette heart rate variability program (Marquette Electronics, Milwaukee, Wis.). Early and late myocardial MIBG uptakes were measured at 15 and 150 minutes after injection, respectively. MIBG clearance rate from the heart and heart-to-lung and heart-to-mediastinum ratios of MIBG activities were calculated. On the whole, heart rate variability, including low-frequency power, correlated positively, but modestly so, with late MIBG uptake and negatively with MIBG clearance rate. The plasma norepinephrine level correlated negatively with late MIBG uptake and with heart rate variability, including low-frequency power, and positively with MIBG clearance rate. Similar correlations were also observed in patient subgroups with coronary artery disease, diabetes mellitus, and renal failure, but these correlations were weak (R² < 0.5).Conclusions. Increased cardiac sympathetic nervous system activity may be associated with increased myocardial MIBG clearance and decreased heart rate variability, including low-frequency power. Because these associations were not strong, however, the combination of heart rate variability with MIBG may allow an interactive assessment of the cardiac autonomic nervous system.     

The distribution profiles of very low density and low density lipoproteins in poorly-controlled male,Type 2 (non-insulin-dependent) diabetic patients

Summary The distribution and composition of lipoproteins spanning the very low density and low density lipoprotein spectra have been analysed in ten poorly-controlled, male, Type 2 (non-insulin-dependent), diabetic patients pre-disposed to mild, secondary hypertriglyceridaemia. As compared to age-matched control subjects, the diabetic patients displayed grossly modified, distinctly atherogenic lipoprotein profiles. Modifications were not limited to the very low density lipoprotein profile, as would be expected from the pre-treatment hypertriglyceridaemia. There was also an aberrant low density lipoprotein profile, which was not evident from plasma cholesterol measurements, especially as the diabetic patients at entry were well matched to control subjects with respect to plasma levels of this lipid. Compositional abnormalities were also observed in the poorly-controlled diabetic group, although these were less marked than the distributional changes. There were substantial improvements of the abnormalities detailed above, even over a short treatment period (two weeks), with therapy designed primarily to ameliorate metabolic control. The data suggest that, in the presence of poor metabolic control and hypertriglyceridaemia, occult, atherogenic modifications of low density lipoproteins can occur. The results argue in favour of strict control of triglyceride levels even in diabetic patients with apparently acceptable cholesterol levels.