中国广东2003年严重急性呼吸综合征疫情的流行病学及病原学研究

严重急性呼吸综合征（SARS）全球大流行的源头来自中国广东省的非典型性肺炎疫情爆发。本研究对广东省疫情爆发的病原体进行鉴定，并对SARS在广东省内的发生与传播情况进行介绍。     

Immune status against diphtheria among immigrants from the former USSR who arrived in Israel during 1990–1991

Summary Large outbreaks of diphtheria occurred recently in the former USSR. Between 1989 and 1994, a total of about 600,000 Soviet immigrants arrived in Israel. The immune status against diphtheria in a sample of 992 men aged 17–49 and 195 women aged 17–19, who arrived in Israel during 1990–91, was studied in order to evaluate the need for vaccination. Participants completed a self-administered questionnaire and diphtheria antitoxin antibody levels were measured by means of ELISA. At age 17–19, the prevalence of antitoxin antibody levels below the protective level of 0.01 IU/ml was 4.8% in the men and 2.1% in the women. Among the men, the percentage lacking protection declined from 4.8% at age 17–19 years to 1.6% at age 20–24, and increased to 18.2% at age 35–49. In the oldest group, the prevalence of those lacking protection was considerably higher than for the general Israeli population. In the multivariate analysis, age, mother's education and republic of origin were significantly associated with the absence of protection. Immigrants from the former USSR appear to be more susceptible to diphtheria, thus increasing the possibility of clinical disease, and it is recommended that they receive booster doses of diphtheria toxoid.     

Coregulation of the APO-1 antigen with intercellular adhesion molecule- 1 (CD54) in tonsillar B cells and coordinate expression in follicular center B cells and in follicle center and mediastinal B-cell lymphomas

APO-1 is a 48-Kd transmembrane glycoprotein identical to the Fas antigen and belongs to the nerve growth factor (NGF)/tumor necrosis factor (TNF) receptor family of surface molecules. Cross-linking of APO- 1 induces apoptotic cell death in sensitive cells. We show here that APO-1 is an activation molecule on B cells. It was induced/enhanced on dense and buoyant tonsillar B cells, respectively, through surface Ig cross-linking in combination with interleukin-2 or by interferon-gamma together with tumor necrosis factor-alpha. These conditions also increased the amount of intercellular adhesion molecule-1 (CD54) on these cells. Epstein-Barr virus transformants of peripheral B cells coexpressed APO-1 and CD54 at very high levels. Immunohistologically, Apo-1 was detectable at low levels in a subpopulation of follicle center B blasts and, at higher levels, in sinusoidal B cells. APO-1 was undetectable in follicular mantle B cells and plasma cells. In isolated tonsillar B cells, APO-1 was expressed in CD10+ follicle center cells. In acute B lymphoblastic leukemia, chronic B lymphocytic leukemia, and Burkitt's lymphomas, APO-1 and CD54 molecules were immunohistochemically undetectable. Coordinate expression of these antigens was found in mediastinal B-cell lymphomas. The mode of APO-1 and CD54 expression was correlated in follicle center cell lymphomas (P < .0019), but less stringently in hairy cell leukemia. No association was found in plasmacytomas. This was in line with the differential expression of these molecules found in reactive plasma cells. Expression of APO-1 in B cells of different stages of differentiation and, correspondingly, in certain B-cell neoplasias might suggest a role of this molecule in the induction of B-cell apoptosis. This function might be influenced by CD54 and CD54-mediated signals.     

Evidence for Multiple Atrio-AV Nodal Inputs in the Normal Dog Heart

Multiple Atrio-AVN Inputs in Dog Heart. Introduction : Complete AV block after combined fast pathway (FP) and slow pathway (SP) ablation is uncommon. The purpose of this study was to interrupt activation of these and additional inputs by placing a radiofrequency lesion across the interatrial septum between the FP and SP ablation sites.
Methods and Results : In eight anesthetized open chest dogs, FP ablation induced significant A-H prolongation (δA-H: 51±14 msec; P < 0.001) and a shift of earliest retrograde atrial activation from the anterior septum to the region of the coronary sinus (CS) os. Subsequently, ablation of the interatrial septum across the fossa ovalis was successful in 5 of 8 dogs, changing the sequence of atrial activation (A) so that A at the His-bundle electrogram, which initially preceded A at the CS os (18 ± 4 msec vs 46 ± 7 msec, P < 0.01), now followed CS os A (81 ± 31 msec vs 59 ± 20 msec, P < 0.05). Additional ablation of the SP caused a type II Mobitz AV block or complete AV block in 5 of 8 dogs. The four dogs with complete AV block sbowed a stable, high junctional escape rhytbm at a rate of 64 ± 16 beats/min. Pacing between the ablation lesions and the AV node in one dog showed 1:1 AV conduction and Wenckebach-type AV block indicating preserved AV nodal function. Histology showed necrotic changes in the FP and SP transitional cell zones and in the atrial tissue of the interatrial septum. However, the compact AV node. His bundle, and adjacent atria and transitional cells were undamaged.
Conclusion : There are additional AV nodal inputs in the interatrial septum in addition to the anterior FP and posterior SP inputs. Ablation of all of these may be required, if the aim is production of complete AV block proximal to the AV node with a high Junctional escape rhythm.     

Frustrated and Confused: The American Public Rates its Cancer-Related Information-Seeking Experiences

BACKGROUND Ensuring access to high-quality cancer-related information is important for the success of cancer prevention and control efforts. OBJECTIVE We conducted a population-based assessment of the barriers faced by people searching for cancer information. DESIGN Cross-sectional data from the National Cancer Institute’s 2003 Health Information National Trends Survey. PARTICIPANTS A nationally representative sample of individuals in the USA (n = 6,369). MEASUREMENTS We assessed whether respondents had ever sought cancer-related information and examined ratings of their information-seeking experiences and beliefs regarding causes of cancer and its prevention. Linear and logistic regression models were estimated to determine predictors of negative experiences and associations between experiences and cancer beliefs. RESULTS Nearly one half (44.9%) of Americans had searched for cancer information. Many reported negative experiences, including the search process requiring a lot of effort (47.7%), expressing frustration (41.3%), and concerns about the quality of the information found (57.7%). Respondents lacking health insurance or a high school education experienced the greatest difficulty. Compared to those reporting the most positive experiences, information seekers reporting more negative experiences were more likely to report that almost everything caused cancer [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.5–2.6], that not much can be done to prevent cancer (OR 2.7, 95% CI 1.9–3.8), and that it is hard to know which cancer prevention recommendations to follow (OR 3.2, 95% CI 2.3–4.5). CONCLUSIONS While a significant proportion of the American public searches for cancer information, suboptimal experiences are common. Facilitation of information seeking will be critical for promoting informed decision making in cancer prevention and control.     

Atrial Electrophysiologic Remodeling: Another Vicious Circle?

AF-Induced Electrophysiologic Remodeling. Introduction : With few exceptions, acquired heart di.sease is the result of (gradual changes in the heart, progressing during several months or years. This also includes certain cardiac arrhythmias, as for instance atrial fihrillation (AF). In spite of the important role of slowly progressing pathologic processes, most of our knowledge about mechanisms of cardiac arrhythmias is hased on acute experiments. Only recently, the attention also is more focused on long-term adaptation processes like cardiac memory, electrical remodeling, and tachycardia-induced cardiomyopathy. In experimental animal models, it has heen shown that AF induces a vicious circle of electrophysiologic and structural changes that inevitahly leads to "domestication" of the arrhythmia ("AF begets AF"). In this article, the studies on AF-induced electrophysiologic and cellular remodeling are discussed.