谷氨酸对腺苷A2A受体调节一氧化氮合酶活力的影响

目的探讨谷氨酸是否能够影响腺苷A2A受体对一氧化氮合酶（NOS）活力的调节。方法用1000ng／ml脂多糖（LPS）刺激小胶质细胞，分别加入100nmol／L A2A受体激动剂CGS21680以及不同浓度的谷氨酸（0，1，0，25，0，5mmol／L）干预，观察NOS活力变化。结果LPS诱导NOS活力增高，激活A2A受体可以产生抑制作用；0，25及0．5mmoL／L谷氨酸和A2A受体激动剂同时存在时，NOS活力进一步增高。结论高浓度谷氨酸可逆转腺苷A2A受体激动剂抑制升高NOS活力的作用。     

No excess of DR*3/4 in Ashkenazi Jewish or Hispanic IDDM patients

The gene frequencies, haplotype relative risks, and zygotic assortments of HLA-DR in three ethnically defined samples of insulin-dependent diabetes mellitus (IDDM) patients were determined in a prospective family study. Although DR3 and DR4 were positively associated with IDDM in the probands of 123 northern European, 94 Ashkenazi Jewish, and 49 New York Hispanic families, significant excess of DR*3/4 heterozygotes was observed only among the probands from families of northern European ancestry. There was also a significant decrease in the frequency of Bw62,DR4 haplotypes derived by northern European patients from their mothers compared with their fathers. This difference, together with data reported in the literature, suggests that the expressivity of the susceptible genotype(s) in IDDM patients may be modified by protective maternal effects associated with Bw62,DR4 and probably other DR4 haplotypes. Samples of IDDM patients from populations with high frequencies of these modifiers should have different DR-gene frequencies contributed by fathers and mothers, capable of accounting for the observed Hardy-Weinberg disequilibrium. We postulate that, because the mechanism of action of these modifiers is distinct from that of the susceptibility gene, the difference must be considered in devising strategies for elucidation of the mode of inheritance of the disease and for understanding the molecular nature of the susceptibility.     

Severe odontogenic infections

Background : Severe odontogenic infections are serious potentially lethal conditions. Following the death of a patient in the authors' institution this study was initiated to determine the risk factors, management and outcome of a consecutive series of patients.
Methods : All patients admitted to the Royal Adelaide Hospital under the care of the Oral and Maxillofacial Surgery Unit with odontogenic infections in calendar year 2003 were investigated. Detailed information relative to their pre-presentation history, surgical and anaesthetic management and outcome was obtained and analysed.
Results : Forty-eight patients, 32M, 16F, average age 34.5, range 19 to 88 years were treated. All presented with pain and swelling, with 21 (44 per cent) having trismus. Forty-four (92 per cent) were as a result of dental neglect and four (8 per cent) were regular dental patients having endodontic treatment which failed. Of those known to have been treated prior to presentation, most had been on antibiotics. Most patients had aggressive surgical treatment with extraction, surgical drainage, high dose intravenous antibiotics and rehydration. The hospital stay was 3.3 (range 1–16) days. Patients requiring prolonged intubation and high dependency or intensive care (40 per cent) had longer hospitalization. No patient died and all fully recovered.
Conclusion : Severe odontogenic infections are a serious risk to the patient's health and life. Management is primarily surgical with skilled anaesthetic airway management. Antibiotics are required in high intravenous doses as an adjunct and not as a primary treatment.     

Calcium paradox in skeletal muscles: physiologic and microscopic observations

Immersion of rat hemidiaphragms in Ca2+-free Krebs solution (KS) containing Ca2+ chelator in vitro leads to separation of basal lamina from the plasma membrane, as well as transient contracture and rapid loss of twitch response [calcium paradox (CP) phase 1]. Subsequent immersion in regular KS results in necrosis of muscle fibers accompanied by slowly increasing contracture (CP phase 2). This contracture could be prevented or reduced by using either Ca2+-free KS or calcium channel blockers, but not by dantrolene sodium, implying that after drastic reduction of extracellular and sarcolemmal Ca2+ during CP phase 1, the sarcolemma has lost its ability to control normal Ca2+ fluxes. Contracture did not develop at 21 degrees C. CP is a convenient model to study calcium-induced muscle cell death and the role of Ca2+ in maintaining sarcolemmal integrity.     

18 Graduate Medical Education and Knowledge Translation: One Problem-Specific Approach in Residency

Traditional graduate medical education approaches to improving clinical performance based upon the latest research have included Journal Club and didactic lectures. Unfortunately, these educational interventions have rarely been demonstrated to change practice behavior or improve patient-important outcomes. Using a structured approach to identifying a gap between best-evidence knowledge and clinical practice, an illustrative one-year residency-wide translational research project was developed in a four year emergency medicine training program. Step one (assigned to the second year residents): identify and quantitatively justify a Knowledge Translation (KT) deficit within our institution. They identified steroids in adult bacterial meningitis as an unequivocal therapeutic option. Based upon a structured one-year chart review, they next demonstrated that only 7% of meningitis patients received pre-antimicrobial steroids. The next step (assigned to the first year residents): identify and quantify the physician "leaks" within the pipeline of information from publication to bedside utilization via an online survey. The third year residents hypothesized plugs for these information leaks, including examples of other specialties or institutions which have successfully navigated this specific clinical scenario. Finally, at an end-of-year Journal Club, the fourth year residents formulated a protocol for the appropriate use of steroids in suspected adult meningitis and brought together individuals from within the institution contributing to the best-practice leak. Knowledge Translation involves multiple stages beyond simple evidence awareness and usually involves continuation beyond the emergency department. The Washington University KT project offers a structured, multidisciplinary example of moving beyond contemplation to implementation of an unequivocal therapy.     

鼻咽癌CT灌注成像及其生物学相关性研究

目的研究鼻咽癌CT灌注值与肿瘤微血管密度（MVD）、肿瘤分期的关系，探讨多层螺旋CT灌注成像对鼻咽癌的临床应用价值。方法49例鼻咽部CT灌注检查中，鼻咽癌组30例，鼻咽癌放疗后组14例，正常鼻咽部5例，测量鼻咽癌和鼻咽黏膜位置的血流量（BF）、最大强化指数（PEI）、峰值到达时间（TTP）及血容量（BV）作为灌注指标，其中16例鼻咽癌活检组织行免疫组织化学CD34单抗染色后，Weidner方法计数MVD。各组灌注值比较行方差分析，CT灌注值、肿瘤分期与MVD之间行Spearman等级相关分析。结果49例中1例鼻咽癌灌注检查失败。鼻咽癌组（29例）肿瘤CT灌注值BF为（48．6±16．9）ml·100g^-1·min^-1，PEI为（32．3±7．9）HU，TTP为（17．5±4．9）s，BV为（12．8±4．4）ml·100g^-1；正常对照组（5例）BF、PEI、TTP、BV值分别为（15．9±5．9）ml·100g^-1·min^-1、（12.6±1．3）HU、（22．6±6．9）s、（3．5±0．5）ml·100g^-1；鼻咽癌放疗后组（14例）BF、PEI、TTP、BV值分别为（25．2±7．0）ml·100g^-1·min^-1、（19．8±5．9）HU、（22．6±4．3）s、（6．1±2．4）ml·100g^-1，三组各灌注值差异有统计学意义（P值均〈0．01）；相关分析显示，鼻咽癌组（29例）中TNM分期（其中Ⅰ期3例，Ⅱ期9例，Ⅲ期10例，Ⅳ期7例）与PEI和BV存在相关性（r值分别为0．48和0．50），与BF和TTP无明显相关性（r值分别为0．23和0．22）；16例鼻咽癌MVD为（30．8±12．6）个／高倍镜视野，与其BF（51．4±17．0）ml·100g^-1·min^-1、PEI（33．2±9．6）HU和TTP（16．3±4．1）8存在相关性（r值分别为0．85、0．60和0．78），与BV（13．2±5．6）ml·100g^-1弱相关（r=0．48）。结论鼻咽癌有着特征的CT灌注表现，多层螺旋CT灌注成像的灌注值可以反映鼻咽癌微血管密度特征，PEI和BV值与鼻咽癌的TNM分期存在一定的相关性。     

急性重症胆管炎的介入治疗

目的讨论经皮经肝穿刺放置引流管(简称PTCD)减压引流治疗急性重症胆管炎(简称AOSC)的可行性及疗效.方法 1996年3月～2001年4月行PTCD治疗AOSC病人15例,男10例,女5例,胆石症术后8例,胆管癌2例,胰腺癌3例,胆道畸形2例,其中4例放置了胆道内支架.结果 15例病人技术成功率100%,无1例出现穿刺置管所致的严重并发症.病情缓解后针对病因有8例行手术治疗痊愈,4例不能手术的肿瘤患者植入了胆道内支架,1例于置管后3d死于多脏器功能衰竭,2例置管引流病情稳定后因各种原因放弃继续治疗,保留引流管自动出院.结论 PTCD可有效降低胆管压力,缓解病情,降低AOSC的死亡率,为进一步的病因治疗创造条件.     

骨科手术患者术中自体血回输的临床观察

目的:探讨骨科手术患者术中自体血回输的临床效果,以期能减少异体血的用量。方法:将骨科择期手术患者,术中随机分为自体血回输组,及异体血输血组,比较两组术后24h伤口引流量、血常规等情况。结果:两组患者手术顺利,自体血回输组术中均未用异体血,但少数患者术后发生低凝状态,输入异体血。结论:术中自体血回输能减少异体血输入量,但须适当补充新鲜血浆和凝血因子。