Cardiac injuries--a clinical and autopsy profile

One hundred two patients sustaining cardiac injuries over a 4-year period were analysed to highlight the natural history of the cardiac injuries. There were 45 blunt, 36 stab, and 21 gunshot injuries. The injury involved the ventricle in 85, atrium in seven, pulmonary artery in five cases, and resulted in crush injury to the heart in the remaining five cases. Thirty-three patients (32.3%) died on the scene and 58 (56.9%) died during the transportation. Only 11 patients (10.8%) reached the hospital alive, and ten of these patients survived following thoracotomy and repair of the cardiac injury. The factors influencing the natural course of cardiac injury were analysed: 2.2% of patients with blunt cardiac trauma reached the hospital alive compared to 19.4% with stab and 14.3% with gunshot injuries; ventricular injuries had a greater prehospital mortality compared to atrial or pulmonary artery injuries; 11.3% of patients sustaining injury to right ventricle reached the hospital alive compared to 3% of those with left ventricular injuries. These data emphasize the need for rapid transport, immediate recognition, and aggressive surgical management, to make a favourable impact on the natural history of cardiac injuries.     

Pharmacology of the alkaloid pumiliotoxin-B. II. Possible involvement of calcium and sodium-dependent processes in nerve and skeletal muscle

The mechanism of the twitch potentiating action of pumiliotoxin-B (PTX-B), an indolizidine alkaloid from the skin of the frog Dendrobates pumilio, was studied on frog skeletal muscles. In the presence of PTX-B, a single stimulus to the muscle produced either a burst of repetitive action potentials superimposed on a depolarizing afterpotential or a single potential with a prolonged afterpotential at junctional as well as extrajunctional regions of the frog skeletal muscle fibers. The alkaloid did not cause repetitive activity in quiescent cells or spontaneous contractions. The duration of the burst of action potentials was related inversely and the amplitude and duration of postburst depolarizing after-potential was related directly to the concentration of PTX-B. The typical pattern of repetitive action potentials and postburst depolarization induced by PTX-B could be mimicked by depolarizing the muscle membrane with current pulses of long duration (150-470 ms). Lowering the external calcium or sodium concentration reduced the ability of PTX-B to initiate repetitive action potentials, whereas a low external chloride concentration had no effect. The frequency of MEPPs evoked by potassium, but not the spontaneous MEPP frequency, was increased by PTX-B, suggesting a selective effect on evoked transmitter release. PTX-B evoked repetitive EPPs in response to a single stimulus applied to the nerve, which was dependent upon the external calcium ion concentration. The amplitudes of EPPs in the train were facilitated, and their amplitude increased linearly at the lowest calcium concentration, but not at concentrations from 0.45 to 1.8 mM.(ABSTRACT TRUNCATED AT 250 WORDS)     

输精管结扎对家兔心功能及心肌NE含量的影响

本实验用日本大耳白兔复制输精管结扎的长期动物模型，分为结扎２５月组（ＶＧ２５），同龄假手术２５月组（ＳＯＧ２５）；结扎６月组（ＶＧ６），同龄假手术６月组（ＳＯＧ６）。记录各组家兔心功能，检测心肌及血清ＮＥ含量，称取心重（ＷＨ）。结果表明，左心室收缩期末压（ＬＶＳＰ），ＶＧ略高于ＳＯＧ；左心室舒张末压（ＬＶＥＤＰ），Ｖ６２５显著的低于ＳＯＧ２５Ｐ＜０．０５），ＶＧ６与５ＯＧ６比较虽无显著差异，也呈低值；±ｄｐ／ｄｔｍａｘ，ＶＧ均明显高于ＳＯＧ（Ｐ＜０．０１）。相关检验表明，＋ｄｐ／ｄｔｍａｘ与血清及心肌ＮＥ含量无相关性；心重与＋ｄｐ／ｄｔｍａｘ呈明显正相关，Ｐ＜０．０５；在２５月组，ＬＶＳＰ与＋ｄｐ／ｄｔｍａｘ呈正相关，Ｐ＜０．０５。提示输精管结扎可提高心肌收缩功能。     

Brain enzyme levels in CSF after cardiac arrest and resuscitation in dogs: markers of damage and predictors of outcome

Levels of brain creatine kinase (CK), aspartate aminotransferase (ASAT), and lactate dehydrogenase (LD) in CSF after cardiac arrest were studied in dog models. Ventricular fibrillation cardiac arrest lasting 10 min or asphyxiation cardiac arrest lasting 0-10 min was followed by cardiopulmonary resuscitation and 96-h intensive care. Outcome was scored as neurologic deficit (0% = normal, 100% = brain death) and overall performance category (1 = normal, 5 = death). Both measures correlated with EEG return time after asphyxiation cardiac arrest, but not after ventricular fibrillation cardiac arrest. Peak activity of enzymes in CSF at 48-72 h post arrest correlated with outcome, and CK was the best predictor. Brain histopathologic damage score at autopsy 96 h post arrest correlated with CK level in CSF (r = 0.79, n = 39) and neurologic deficit (r = 0.70, n = 50). Ischemic neuronal changes occurred after ventricular fibrillation cardiac arrest of 10 min, and neuronal changes plus microinfarcts occurred after asphyxiation cardiac arrest of 1.5-10 min. Brain enzymes were decreased at 6 h post arrest in regions with worst histologic damage (gray matter of neocortex, hippocampus, caudate nucleus, cerebellum). Brain CK decreased further, ASAT remained low, and LD increased at 72 h after arrest. The temporal changes in CK level paralleled the temporal ischemic neuronal changes in the brain, and time to peak activity was unaffected by the severity of the ischemic insult. Peak activity of individual enzymes in CSF was determined predominantly by the brain concentration, but was also influenced by rate of decomposition. This "chemical brain biopsy method" represents a useful adjunctive tool to predict permanent, severe brain damage during comatose states after cardiac arrest and resuscitation.     

Iridoid Glucosides from the Leaves of Citharexylum fruticosum

A new iridoid glucoside, 5-deoxypulchelloside I, along with the three known iridoid glucosides, phlomiol, lamiid, and lamiidoside, were isolated from the leaves of CITHAREXYLUM FRUTICOSUM. The structure of the new compound was established by spectroscopic methods.     

The effects of a "low-risk" diet on tumor incidence in chemically induced colon cancer in rats

The relationship between various dietary constituents and colon cancer has been demonstrated by previous research. We conducted a study to investigate the combined effects of several dietary constituents on intestinal tumor incidence in azoxymethane (AOM)-induced colon cancer in rats. A nutritionally adequate, "low-risk" (LR) diet was formulated through nonextreme dietary manipulations of dietary fat, fiber, protein, vitamins A and E, and selenium. Seventy-two female F344 weanling rats were given three weekly subcutaneous injections of either AOM or physiological saline solution, and were maintained on either the LR or a "high-risk" (HR) diet. Food consumption and body weights were monitored on a weekly basis throughout the study. Tumor incidence was determined 36 weeks following the first injection of AOM. The incidence of adenocarcinomas in the LR diet group was 4.2% compared with 29.2% in the HR diet group. There were no significant differences in the incidence of small intestinal tumors or in the incidence of benign polyps between the diet groups. The results of the study indicated a significant protective effect of the various chemopreventive dietary factors when combined in an LR diet for colon cancer.     

2010—2021年国内外老年多重慢病研究热点分析

背景 随着人口老龄化进程的加快,同时患有多种慢病已成为老年人的常态,老年多重慢病相关研究也不断丰富,但鲜有对其研究进展及热点进行分析。目的 分析国内外老年多重慢病的研究热点,揭示近十年来（2010—2021年）老年多重慢病领域研究前沿的热点主题,为相关研究者追踪前沿信息提供参考。方法 基于文本挖掘技术和文献计量学等方法,检索Web of Science核心合集、Scopus、中国知网、万方数据知识服务平台、维普网、PubMed、中华医学会期刊全文数据库、APA-PsycINFO美国心理学会数据库中老年多重慢病领域的相关文献,检索时间为2010—2021年。使用CiteSpace 6.1.3、PASW 18、BICOMB 2.04等软件对文献的发文量趋势、来源、作者、机构、关键词等方面进行分析及可视化,并绘制战略坐标图对领域研究热点进行分析。结果 最终纳入老年多重慢病相关文献9 392篇,其中外文文献5 776篇,中文文献3 616篇。2010—2021年老年多重慢病领域中外文献发文量均呈指数型增长,中文文献年增长率为13.27%,外文文献年增长率为15.84%,该领域正处于发展阶段。中...     

Use of laser to extract unwanted pacemaker leads

Of the total number of pacemakers implanted each year, 6% must eventually be replaced because of infection, lead failure, or other problems. Often however, removal of the pacing leads is precluded by scarring at the tip of the leads. Because abandoned leads can cause serious problems, we initiated the present study to test the feasibility of using a laser to remove such leads. After performing in vitro experiments to establish the laser settings required for severing leads, we implanted 6 leads, from 4 different manufacturers, in 3 dogs. Five weeks later, we passed a laser fiber through each lead to the tip and delivered a 10-watt impulse for 2 seconds, which resulted in the successful removal of all the leads. When the dogs were killed 3 days later, postmortem examination revealed no thromboembolism in the heart or lungs and no myocardial damage. Subsequent experiments in 3 human cadaver hearts-involving leads implanted for 5 years, 2 years, and 2 months-yielded the same satisfactory results as did the canine experiments.     

Tumor thickness and prognosis in clinical stage I malignant melanoma

The current grouping of patients with malignant melanoma into thin, intermediate, and thick melanomas provides a convenient but arbitrary classification which, although providing "average" survival values for each group, offers crude prognostication for the individual patient. A review of 371 patients with clinical Stage I malignant melanoma, treated during the period 1970 to 1985, was conducted. The estimated 5-year survival rate for female patients with melanomas 1.0 mm thick was 94%; for each 1-mm increment in thickness the survival rate declined by about 3%, up to the 6 mm mark, the survival rate declining thereafter by about 8% for each additional millimeter in the range of 7 to 15 mm of thickness. The estimated 5-year survival rate for male patients with melanomas 1.0 mm thick was 80%; for each 1-mm increment the survival rate declined by about 9%, up to the 10 mm mark. The proposed method of estimating the expected survival according to the patient's sex and the thickness of the primary lesion hopefully provides a more accurate and convenient method of prognostication for the clinician dealing with specific patients with intermediate or thick melanomas.