Freezing of gait in postmortem-confirmed atypical parkinsonism.

The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies.     

百年乐与人参黄芪合剂对心血管系统的药理作用比较

百年乐和人参黄芪合剂对心血管系统的作用研究表明:百年乐能加速小鼠肠系膜微循环障碍的恢复,增加离体兔耳血管的流量,使主动脉平滑肌松弛,对抗心肌缺氧,抑制血栓形成,其作用强于人参黄芪合剂。     

Successful choledochojejunostomy for choledochal stricture with preservation of the collateral parabiliary venous system following iatrogenic portal occlusion

We surgically treated a patient with biliary stricture and portal vein occlusion, after operation for gastric cancer with lymphadenectomy along the hepatoduodenal ligament, that had led to choledochal stone formation and a dilatated parabiliary venous system. A 57-year-old man without hepatic dysfunction exhibited hepatic duct dilatation with choledochal stone on ultrasonography and percutaneous transhepatic cholangiography, respectively. Pharmacoportography revealed occlusion of the portal vein and dilatation of the parabiliary venous system. Of various preoperative imaging studies used, enhanced computed tomography was most useful for delineating the surgical anatomy of the hepatoduodenal ligament. Complete preservation of the dilatated vessels, which functioned as the main portal collateral pathway, resulted in a successful choledocho-jejunostomy, with an uneventful postoperative course.     

Discrete time optimal control of linear time-delay systems

A discrete time optimal control for linear time-delay systems is developed to ensure that all closed-loop eigenvalues will lie inside a circular region centred at (β;, 0) with radius α. It is shown that by suitable manipulations the problem can be reduced to a standard discrete time quadratic regulator problem. An illustrative example is included to demonstrate the applicability of the proposed method.     

关于高等医学教育管理体制与学制改革的思考

高等医学教育管理体制与学制改革是二十一世纪社会发展的需要。文章阐述了医学教育小规模、长学制、高投入的基本特征,强调了遵循医学教育规律的重要性,分析了医学院在综合性大学的重要地位,医学院与附属医院以及相关院系的关系。文章还依据社会发展的需要和医学教育国际化的趋势,分析了医学教育学制调整的必要性以及学制调整思路。     

Preventing heart disease: is treating the high risk sufficient?

Monte Carlo simulation was used to assess the effects of several intervention strategies on coronary heart disease mortality rates in a Finnish and a North American cohort. Lowering total serum cholesterol by 4%, smoking by 15%, and diastolic blood pressure by 3% for the whole cohort would be expected to reduce the incidence of non-fatal myocardial infarction by at least 13% and coronary heart disease deaths by at least 18%. Lowering serum cholesterol by 34%, diastolic blood pressure to 90 mmHg, and reducing smoking by 20% in the subset of the population with all three risk factors in the highest quartile would result in a 6-8% reduction in non-fatal myocardial infarction and a 2-9% reduction in deaths from coronary heart disease in these cohorts. These data demonstrate that in populations with a relatively high incidence of heart disease, treating the entire population will produce larger effects than focusing only on high-risk populations.     

Nursing in the health care system of the postmodern world: crossroads, paradoxes and complexity

Entering the postmodern world in which society is confronting crossroads, paradoxes, and complexity, the health care system is encountering a transformation more comprehensive and revolutionary than has ever been seen before. Analysis of the state of nursing vis a vis these transformations indicates that the current paradigm does not ensure the existence of the profession in the postmodern health care system. That is because of increased difficulties in consolidating the economic and quality issues into the core of nursing, and in understanding the complexity inherent in health related situations.     

Circular dichroism detection in high-performance liquid chromatography: Evaluation of the anisotropy factor

The application of a circular dichroism (c.d.) detection system in HPLC using a chiral stationary phase is presented. The simultaneous measurement of the absorbance and c.d. signal allows the evaluation of the anisotropy factor (g = Δ/) and thus the determination of the enantiomeric excess (e.e.) of the eluates. When this detection system is used in preparative chiral chromatography the collection of the enantiomeric fractions can be readily optimized.     

Serotonin-induced increase in cAMP in ganglia isolated from the myenteric plexus of the guinea pig small intestine: Mediation by a novel 5-HT receptor

Serotonin (5-HT) is a mediator (through 5-HT_1P receptors) of slow EPSPs in myenteric ganglia of the small intestine. The effect of 5-HT can be mimicked by elevating cAMP; therefore, we tested the hypothesis that the slow EPSP-like response to 5-HT is cAMP-mediated. Guinea pig gut was enzymatically dissociated; myenteric ganglia remained intact and were collected by filtration. Neurons in the isolated ganglia retained their ability to manifest the slow EPSP-like response to 5-HT. Exposure to 5-HT raised the ganglionic level of cAMP (ED₅₀ 0.3 μM). This effect was not antagonized by the 5-HT_1P antagonist, N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan amide (100.0 μM), or mimicked by the 5-HT_1P agonist, 5-hydroxyindalpine (10.0 μM). Increases in cAMP were also evoked by the 5-HT₁ agonist, 5-carboxyamidotryptamine (10.0 μM), the 5-HT₂ agonist, (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI; 1.0–10.0 μM), and by the 5-HT₄ agonists, renzapride (1.0–10.0 μM) and 5-methoxytryptamine (1.0–10.0 μM); however, neither the 5-HT₁/5-HT₂ antagonists, spiperone, methysergide, and methiothepin, nor the 5-HT₄ antagonist, tropisetron (ICS 205–930; 10.0 μM), were able to inhibit the rise in cAMP evoked by these compounds or by 5-HT (0.1–10.0 μM). The 5-HT-evoked elevation of cAMP was antagonized by ketanserin (10.0 μM), which also blocked the effects of 5-methoxytryptamine and DOI, but not those of renzapride. The effective concentration of DOI, however, was higher than that needed for activation of 5-HT₂ receptors, and Northern analysis using a cDNA probe encoding the rat 5-HT₂ receptor failed to reveal the presence of 5-HT₂ mRNA in myenteric ganglia, although it hybridizes with mRNA of the right size in the guinea pig brain. Compounds that failed to change levels of cAMP or to antagonize the action of 5-HT included 8-hydroxy-di-n-propylamino tetralin, R58639, R88226, and sumatriptan. It is concluded that the receptor responsible for the 5-HT-induced rise in cAMP in ganglia isolated from the guinea pig myenteric plexus is not a known subtype of 5-HT receptor. Since the pharmacology of this novel receptor is different from that of the slow EPSP-like response to 5-HT, the receptor probably does not mediate the slow EPSP. © 1993 Wiley-Liss, Inc.