Occurrence of Salmonella enteritidis in unpasteurized liquid egg in the United States.

In order to gain a greater understanding of the occurrence and distribution of Salmonella enteritidis in the United States, a survey of unpasteurized liquid egg (collected at 20 egg-breaking plants across the United States) was conducted over a 52-week period. Weekly liquid egg samples were submitted for Salmonella culturing at the National Veterinary Services Laboratories. Group D positive salmonellae were serotyped and phage-typed. On a regional basis, the Northern Region of the United States had the highest S. enteritidis recovery, with 20% of the samples submitted from plants in that region culture-positive for this serotype. Salmonella enteritidis positives from the Southeast, Central, and Western regions were 10%, 15%, and 6% of the samples submitted, respectively.

Predictors of major bleeding in peri-procedural anticoagulation management.

BACKGROUND: Appropriate periprocedural management for chronically anticoagulated patients requires assessment of patient-specific thrombosis and bleeding risks. However, predictors of post-procedure bleeding are unknown. OBJECTIVES: To determine the 3-month cumulative incidence and independent predictors of peri-procedural bleeding in chronically anticoagulated patients requiring temporary warfarin interruption for an invasive procedure. METHODS: In a protocol driven, cohort study design, all patients referred to the Mayo Clinic Thrombophilia Center for peri-procedural anticoagulation management (1997-2007; n = 2182), were followed forward in time to determine the 3-month cumulative incidence of peri-procedural bleeding (Kaplan-Meier product limit) and potential predictors of bleeding (Cox proportional hazards). Decisions to 'bridge' with low-molecular-weight heparin were based on estimated thromboembolism and bleeding risk. RESULTS: Indications for chronic anticoagulation included venous thromboembolism (38%), atrial fibrillation (30%) and mechanical heart valves (27%). Of these, 1496 (69%) patients received bridging therapy. The 3-month cumulative incidence rates of major and overall bleeding were 2.1% and 5.1%, respectively. Major bleeding occurred more frequently in patients receiving bridging therapy (3% vs. 1%; P = 0.017). Independent predictors (hazard ratio; 95% confidence interval) of major bleeding included mitral mechanical heart valve (2.2; 1.1-4.3), active cancer (1.8; 1.0-3.1), prior bleeding history (2.6; 1.5-4.5) and re-initiation of heparin therapy within 24 h after the procedure (1.9; 1.1-3.4). CONCLUSION: Factors predisposing to peri-procedural bleeding are primarily patient-specific. Premature heparin re-initiation is an avoidable provider-specific variable to consider.

The U.S. Thrombosis and Hemostasis Centers pilot sites program.

Venous thromboembolism (VTE) is a common disorder associated with significant morbidity and mortality. Despite important advances in understanding the etiology of VTE, delivery of care to patients with thrombosis and thrombophilia is frequently incomplete and highly variable. A comprehensive model of health care has been used successfully to treat and prevent complications for people with hemophilia and other chronic disorders. The effectiveness of an integrated healthcare model for patients with all coagulation disorders has yet to be evaluated. The Division of Hereditary Blood Disorders of the Centers for Disease Control and Prevention (CDC) is collaborating with eight Thrombosis and Hemostasis Centers (pilot sites) to provide health-related services and conduct research directed toward the reduction or prevention of complications of thrombosis and thrombophilia. The initial objectives of the collaboration are to (1) determine the efficacy of integrated multidisciplinary care and prevention services for people with hemostatic disorders, (2) assess unmet needs for service delivery and identify outreach strategies to improve access to care, (3) develop effective messages aimed at disease management and prevention, and (4) foster the development of training programs to enhance provider skills for the delivery of patient care. To address these objectives, the investigators and CDC have developed and implemented a web-based patient registry to follow prospectively service allocation and patient outcomes. Funding for the program began in October 2001. All eight funded centers are affiliated with U.S. medical schools. Principal investigators at the centers are hematologists (five adult, two pediatric) or cardiologists. Faculty in obstetrics-gynecology, surgery, and multiple other specialties are integral to the model of care at the centers. Other critical components at the centers are clinical laboratory services, training programs, research networks, and education and outreach programs. From August 2003 to March 2006, over 2,600 patients were enrolled in the registry, accounting for a total of more than 5,000 visits to the centers. Immediate goals of the data collection at the centers are to characterize patients receiving care at centers and document the state of health services provided. Long-term goals are to evaluate prospectively clinical outcomes for patients receiving multidisciplinary care and prevention services at centers. The network of data collection across centers will facilitate future collaborative clinical and epidemiologic investigations and enhance collective expertise in hemostasis and coagulation disorders.

Asynchronous transfer mode distribution network by use of an optoelectronic VLSI switching chip.

We describe a new optoelectronic switching system demonstration that implements part of the distribution fabric for a large asynchronous transfer mode (ATM) switch. The system uses a single optoelectronic VLSI modulator-based switching chip with more than 4000 optical input-outputs. The optical system images the input fibers from a two-dimensional fiber bundle onto this chip. A new optomechanical design allows the system to be mounted in a standard electronic equipment frame. A large section of the switch was operated as a 208-Mbits/s time-multiplexed space switch, which can serve as part of an ATM switch by use of an appropriate out-of-band controller. A larger section with 896 input light beams and 256 output beams was operated at 160 Mbits/s as a slowly reconfigurable space switch.

Five-stage free-space optical switching network with field-effect transistor self-electro-optic-effect-device smart-pixel arrays.

The design, construction, and operational testing of a five-stage, fully interconnected 32 × 16 switching fabric by the use of smart-pixel (2, 1, 1) switching nodes are described. The arrays of switching nodes use monolithically integrated GaAs field-effect transistors, multiple-quantum-well p-i-n detectors, and self-electro-optic-device modulators. Each switching node incorporates 25 field-effect transistors and 17 p-i-n diodes to realize two differential optical receivers, the 2 × 1 node switching logic, a single-bit node control memory, and one differential optical transmitter. The five stages of node arrays are interconnected to form a two-dimensional banyan network by the use of Fourier-plane computer-generated holograms. System input and output are made by two-dimensional fiber-bundle matrices, and the system optical hardware design incorporates frequency-stabilized lasers, pupil-division beam combination, and a hybrid micro-macro lens for fiber-bundle imaging. Optomechanical packaging of the system ut lizes modular kinematic component positioning and active thermal control to enable simple rapid assembly. Two preliminary operational experiments are completed. In the first experiment, five stages are operated at 50 Mbits/s with 15 active inputs and outputs. The second experiment attempts to operate two stages of second-generation node arrays at 155 Mbits/s, with eight of the 15 active nodes functioning correctly along the straight switch-routing paths.