A C ASE S ERIES A NALYSIS OF M ASS C ASUALTY I NCIDENTS

Introduction. Mass casualty incidents (MCIs) are infrequent but potentially overwhelming events that can stress the capabilities of even the most organized emergency medical services (EMS) system. The Maryland EMS system has been identified as a pioneer and leader in the field of prehospital emergency care and, as with many states, Maryland's regional preparation for MCIs has been integrated into its overall EMS systems planning. Objective. To determine how successful this integration has been by examining a three-year history of response to MCIs in Maryland. Methods. A three-year case series of MCIs in Maryland was obtained from a Nexis national news publications search. These MCIs were cross-referenced with U.S. postal ZIP codes and the U.S. Census Bureau's ZIP code files. They were then mapped and summary statistics were prepared for analysis. Data obtained through the Maryland Health Services Cost Review Commission for all severely injured patients discharged from Maryland hospitals were obtained over the same three-year period for comparison. Results. Eight MCIs occurred over a three-year period, resulting in a total of 203 injuries. An average of 25.4 ± 10.7 injuries occurred per MCI. A total of 158 (77.8%) of injuries necessitated ambulance transportation. An average of 3.1 ± 1.1 hospitals were involved per MCI. Conclusions. The Maryland EMS system was effective in responding to MCIs ranging in size from 10 to nearly 40 injuries. Analyzing MCIs that reoccur on a year-to-year basis should figure into the planning process for EMS systems.     

一种快速分离C2C12细胞核仁的方法研究

[目的]探讨一种快速分离核仁且能保持其完整结构与功能的方法.[方法]采用低渗裂解分离细胞核,密度梯度离心分离细胞核仁,电镜、免疫印迹检测核仁的纯度.[结果]电镜检测发现在放大2 000倍时C2C12肌源细胞核仁呈现为大小基本一致、形态较为规则的黑色阴影,放大25 000倍时可见单个网孔状的核仁,且核仁各组分清晰可见.免疫印迹检测发现核仁纯度较高,没有胞浆蛋白的污染.[结论]本研究建立了一种快速分离细胞核仁的方法.     

输血后HCV感染的前瞻性研究

目的：了解上海地区医院内输血后丙型肝炎病毒（HCV）感染的现状，以制定相应的防治策略。方法：对输血的本院内、外科住院病人采用前瞻性调查。结果：输血后HCV感染率可高达8．48％，而同期住院未输血的对照组未发现HCV感染，而且HCV感染率随输血量增加而呈上升趋势；加强输血前筛查的方法可使感染率降至2．1％左右。结论：在尚无丙型肝炎疫苗的情况下，提倡义务献血和加强对血源的筛查是控制输血后肝炎的有效和必要的措施。     

Isolation of cairomycins A and C.

Cairomycin B in the fermentation broths of Streptomyces sp. strain AS-C-19 accompanied cairomycin A and cairomycin C. The cairomycins are peptides with potent activity against gram-positive bacteria. On acid hydrolysis, cairomycin A yielded valine and aspartic acid, whereas cairomycin C yielded lysine, glycine, valine, leucine, and aspartic acid, as identified by paper and gas chromatography. These amino acids were found to exist in their alpha-L form. Cairomycin A was tentatively assigned a 6-isopropyl-2,5-diketopiperazine-3-acetic acid structure. The three cairomycins were distinct from each other in their ultraviolet, infrared, and mass spectra; elemental analyses; and their chromatographic behavior in different developing solvents.     

C ARDIAC A RREST M ANAGEMENT

Approximately 1,000 people in the United States suffer cardiac arrest each day, most often as a complication of acute myocardial infarction (AMI) with accompanying ventricular fibrillation or unstable ventricular tachycardia. Increasing the number of patients who survive cardiac arrest and minimizing the clinical sequelae associated with cardiac arrest in those who do survive are the objectives of emergency medical personnel. In 1990, the American Heart Association (AHA) suggested the chain of survival concept, with four links—early access, cardiopulmonary resuscitation (CPR), defibrillation, and advanced care—as the way to approach cardiac arrest. The recently published International Resuscitation Guidelines 2000 of the AHA have addressed advances in our understanding of the chain of survival. While the chain of survival concept has withstood a decade of scrutiny, there are only a few scientifically rigorous research studies that support changes in prehospital patient care. Additional research efforts carried out in the prehospital setting are needed to support the concepts included in the chain of survival for cardiac arrest patients. Participants at the second Turtle Creek Conference, a meeting of experts in the field of emergency medicine held in Dallas, Texas, on March 29–31, 2000, discussed these and other issues associated with prehospital emergency care in the cardiac arrest patient. This paper addresses a number of the issues associated with each of the links of the chain of survival, the evidence that exists, and what should be done to achieve the clinical evidence needed for true clinical significance. Also included in this paper are the consensus statements developed from small discussion groups held after the main presentation. These comments provide another perspective to the problems and to possible approaches to deal with them.     

遗传性蛋白C缺陷症家系的一个基因突变

目的 研究一个遗传性蛋白C（PC）缺陷症家系的遗传表型及基因特征。方法 PC活性用凝固法测定，PC抗原用ELISA方法测定。用PCR扩增2代家系12个成员中4个PC活性及抗原减低的PCⅡ-Ⅸ号外显子片段，用单链构象多态性（SSCP）分析cDNA变性后的差异，用测序法检测突变点。用限制性酶切验证突变点，同时分析家系的基因型。结果 该家系2代4名成员PC抗原水平在34．3％－67．8％（参考值80％－120％）。PC活性在22％－49％（参考值70％－130％），较正常参考范围明显减低。限制性酶切分析该家系12名成员时发现9名成员存在基因的突变。基因突变位点在Ⅶ号外显子第6219位核苷酸G→A突变，使正常编码的CGG精氨酸突变为CAG谷氨酰胺。结论 该家系为I型PC缺陷症，基因分析证明先证为杂合子型。在PCⅦ号外显子上第6219位核苷酸G→A突变，在蛋白质合成过程中第169位精氨酸被谷氨酰胺替代（R→Q），为目前国内献中尚未报道的一个基因突变点。     

A MIODARONE AND R URAL E MERGENCY M EDICAL S ERVICES C ARDIAC A RREST P ATIENTS : A C OST A NALYSIS

Objective: Recent American Heart Association guidelines suggest amiodarone as an antiarrhythmic in refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The authors sought to assess the impact of amiodarone use on outcomes and cost associated with this practice in a rural emergency medical services (EMS) state. Methods: Statewide EMS records were reviewed for the calendar year 1999. Data reviewed included prehospital diagnosis, medications given by prehospital providers to patients with cardiac arrest, and procedures performed, including cardiopulmonary resuscitation (CPR) and defibrillation. Cost-benefit analysis assumed the cost of amiodarone treatment to be $137.65 per patient encounter. Absolute risk reduction (ARR) and number needed to treat (NNT) analysis utilized resuscitation rates published in the ARREST and ALIVE trials. Results: During the study period, EMS providers diagnosed 2,189 patients as having cardiac arrest. Five hundred thirty-five (24.4%) cardiac arrest patients were defibrillated. One hundred sixty patients (7.3%), including 15 who did not receive defibrillation, were given lidocaine during resuscitation efforts. The annual cost increase from current practice for a statewide amiodarone VF/VT protocol was $21,822.40 (10,572.87%). The initial cost to stock EMS vehicles for this protocol would be $50,115.52. The cost-benefit analysis yielded a potential for one additional patient survival to hospital discharge in Maine per 3.125 years of system-wide practice at a cost of $68,840.00. Conclusion: Based on current data, instituting amiodarone treatment for refractory VF and pulseless VT in a rural EMS setting requires the investment of substantial resources, relative to current treatment strategies, for any potential survival benefit.     

Radioimmunoassay of human pepsinogen A and pepsinogen C

We describe the development of radioimmunoassays to measure both human pepsinogen A and pepsinogen C concentrations in serum. The antibodies were raised in goats by immunization with purified pepsinogen A or C. The affinity constants of the respective antibodies were 20.10(10) l/mol and 7.10(10) l/mol. Pepsinogens A and C were labeled with Na 125I by the chloramine T method. The binding between labels and antibodies was inhibited by 0.50 at 0.82 ng pepsinogen A per tube and 2.1 ng pepsinogen C per tube. The detection limits of the assay of pepsinogen A and C were 0.12 microgram/l and 1.8 micrograms/l, respectively. Pepsinogen A and C were purified and added to a patient serum, showing a good recovery in the radioimmunoassays. Serial dilution of another patient serum, which contained a high concentration of both antigens, showed curves parallel to the standard curves. The intra- and interassay variations of these radioimmunoassays were evaluated. The intra-assay coefficients of variation for pepsinogen A were found to vary from 0.03 to 0.102 at concentrations in serum in the normal range, while the inter-assay coefficient of variation ranged from 0.118 to 0.194 at the same concentrations in serum. For the pepsinogen C radioimmunoassay we found intra-assay coefficients of variation between 0.126 and 0.147 at concentrations in serum in the normal range, while the inter-assay coefficient of variation ranged from 0.174 to 0.325 for the same sera. In 201 blood donors we found a mean serum concentration of pepsinogen A of 59 micrograms/l and a mean serum concentration of pepsinogen C of 15 micrograms/l. There was a significant relationship between these values (r = 0.779, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

A Small-Molecule Inhibitor of Hepatitis C Virus Infectivity

One of the most challenging goals of hepatitis C virus (HCV) research is to develop well-tolerated regimens with high cure rates across a variety of patient populations. Such a regimen will likely require a combination of at least two distinct direct-acting antivirals (DAAs). Combining two or more DAAs with different resistance profiles increases the number of mutations required for viral breakthrough. Currently, most DAAs inhibit HCV replication. We recently reported that the combination of two distinct classes of HCV inhibitors, entry inhibitors and replication inhibitors, prolonged reductions in extracellular HCV in persistently infected cells. We therefore sought to identify new inhibitors targeting aspects of the HCV replication cycle other than RNA replication. We report here the discovery of the first small-molecule HCV infectivity inhibitor, GS-563253, also called HCV infectivity inhibitor 1 (HCV II-1). HCV II-1 is a substituted tetrahydroquinoline that selectively inhibits genotype 1 and 2 HCVs with low-nanomolar 50% effective concentrations. It was identified through a high-throughput screen and subsequent chemical optimization. HCV II-1 only permits the production and release of noninfectious HCV particles from cells. Moreover, infectious HCV is rapidly inactivated in its presence. HCV II-1 resistance mutations map to HCV E2. In addition, HCV-II prevents HCV endosomal fusion, suggesting that it either locks the viral envelope in its prefusion state or promotes a viral envelope conformation change incapable of fusion. Importantly, the discovery of HCV II-1 opens up a new class of HCV inhibitors that prolong viral suppression by HCV replication inhibitors in persistently infected cell cultures.     

T HE C ALIFORNIA 500: M EDICAL C ARE AT A NASCAR W INSTON C UP R ACE

Background. Stock car racing is America's fastest-growing professional sport. With more than 5.5 million paid admittances and another 148 million watching the 34-race NASCAR Winston Cup series on television, emergency physicians are increasingly called upon to organize medical support for such events. Currently, little reliable information is available to assist in determining what specific personnel and equipment are necessary to optimally support a race event. Objective. To characterize the spectrum of presenting injuries and illnesses at a NASCAR Winston Cup event. Methods. This study was a retrospective review of all patients presenting to nine on-site first aid stations from June 19 to 22, 1997, for the inaugural California 500 race weekend at California Speedway in Fontana, California. Staffing of the nine first aid stations was provided by 20 paramedics, 25 emergency nurses, five emergency physicians, nine advanced life support (ALS) ambulances with two crew members each, and a medically configured helicopter with flight crew. Results. Of the 923 patients seen, 38 were drivers/crew, 230 were track employees, and 644 were spectators. One hundred thirty-six of the patients were treated in the two infield facilities, while 787 were treated in the grandstand first aid stations. Patients seen per hour peaked just before the start of the race at 73 patients seen. Of the ten patients transported to the hospital, three required admission. No deaths occurred. Conclusion. These data may assist individuals planning medical support for large motorsports venues.     

蛋白C基因G12918A突变所致Ⅰ型遗传性蛋白C缺陷症

目的研究一个遗传性蛋白C（PC）缺陷症家系的遗传表型和基因特征。方法PC抗原（PC：Ag）和PS抗原（PS：Ag）检测采用酶联免疫吸附试验，AT抗原（AT：Ag）测定采用免疫比浊法测定；PC活性（PC：A）、PS活性（PS：A）和AT活性（AT：A）采用发色底物法在Sysmex1500全自动血凝仪上进行测定。用聚合酶链反应扩增3代家系10个成员PC基因各个外显子及侧翼序列，用直接测序法检测其基因突变点。结果该家系3代10名成员中，有8名PC抗原水平在1．06～1．92mg/L（参考值3．00～6．00mg/L）之间，PC活性在41％～67％（参考值70％～140％）之间，明显低于正常参考范围；而PS：Ag和PS：A、AT：Ag和AT：A均在正常参考值范围内。PC基因测序分析：8名成员存在Ⅸ号外显子第12918位核苷酸G→T突变，密码子TGG→TGA，使第372位Trp→Stop；并在基因启动子区存在2405C／T、2418A／G、2583A／T的多态性。结论该家系为Ⅰ型遗传性PC缺陷症，PC基因Ⅸ号外显子存在第12918位核苷酸G→T突变，该突变是目前尚未报道的一个新的基因突变点；并在基因启动子区存在2405C／T、2418A／G、2583A／T的多态性。