A magnetically focused molecular beam source for deposition of spin-polarised molecular surface layers.

Separating molecular spin isomers is a challenging task, with potential applications in various fields ranging from astrochemistry to magnetic resonance imaging. A new promising method for spin-isomer separation is magnetic focusing, a method which was shown to be capable of producing a molecular beam of ortho-water. Here, we present results from a modified magnetic focusing apparatus and show that it can be used to separate the spin isomers of acetylene and methane. From the measured focused profiles of the molecular beams and a numerical simulation analysis, we provide estimations for the spin purity and the significantly improved molecular flux obtained with the new setup. Finally, we discuss the spin-relaxation conditions which will be needed to apply this new source for measuring nuclear magnetic resonance signals of a single surface layer.

Hospitalizations associated with salmonellosis among seniors in Canada, 2000-2010.

Salmonella is one of the most prevalent bacteria associated with enteric illness in Canada and seniors are considered a vulnerable population more likely to develop severe illness. In the coming decades, hospitalizations and deaths associated with Salmonella in seniors could represent a challenge due to an aging population in Canada. The numbers of non-typhoidal (NT) Salmonella-related hospitalizations from the Canadian Hospitalization Morbidity Database were analysed for a period of 10 years for seniors. Hospitalization rate calculations and descriptive analyses were performed on variables associated with the burden of hospitalization and compared with the adult age group. Estimates of hospitalizations and deaths associated with domestically acquired Salmonella (accounting for under-reporting) were also calculated. This study found that 50% of the NT Salmonella-related hospitalization and 82% of the deaths recorded in the Canadian adult population occurred in seniors. The length of hospitalization stay was also longer in seniors (7 days) than other adults (4 days). We estimated that each year, 535 hospitalizations and 27 deaths are related to domestically acquired Salmonella in seniors. Senior populations represent a substantial percentage of Salmonella-related hospitalizations and deaths in Canada and the burden associated with those hospitalizations is also greater. This should be considered when developing estimates of medical costs and implementing prevention activities.

Intuitive wireless control of a robotic arm for people living with an upper body disability.

Assistive Technologies (ATs) also called extrinsic enablers are useful tools for people living with various disabilities. The key points when designing such useful devices not only concern their intended goal, but also the most suitable human-machine interface (HMI) that should be provided to users. This paper describes the design of a highly intuitive wireless controller for people living with upper body disabilities with a residual or complete control of their neck and their shoulders. Tested with JACO, a six-degree-of-freedom (6-DOF) assistive robotic arm with 3 flexible fingers on its end-effector, the system described in this article is made of low-cost commercial off-the-shelf components and allows a full emulation of JACO's standard controller, a 3 axis joystick with 7 user buttons. To do so, three nine-degree-of-freedom (9-DOF) inertial measurement units (IMUs) are connected to a microcontroller and help measuring the user's head and shoulders position, using a complementary filter approach. The results are then transmitted to a base-station via a 2.4-GHz low-power wireless transceiver and interpreted by the control algorithm running on a PC host. A dedicated software interface allows the user to quickly calibrate the controller, and translates the information into suitable commands for JACO. The proposed controller is thoroughly described, from the electronic design to implemented algorithms and user interfaces. Its performance and future improvements are discussed as well.

Summary: Assessing the public health risks of microbial contamination in recreational waters by satellite imagery.

BACKGROUND: Fecal contamination of recreational waters may lead to gastroenteritis, respiratory infections, dermatitis and ear infections. In addition to directly testing waters for contamination, the World Health Organization (WHO) recommends the assessment of environmental factors known to influence water quality as part of monitoring efforts. Measurement of these factors using satellite imagery may be helpful in Canada where monitoring over large areas or difficult to access locations is needed. OBJECTIVE: To assess the added value of using satellite imagery as part of monitoring and managing microbial risks associated with recreational waters in Canada. METHODS: Satellite images were used to calculate five environmental indices that may affect the risk of contamination of recreational waters: agricultural land, urban areas (impervious surfaces), forest and wetlands. Statistical models including these indices were then compared with the average contamination level of beaches in southern Quebec, Canada. Various satellite sensors were compared against criteria of accuracy and performance. OUTCOMES: Satellite imagery classification performed well for the study area. Two of the variables were significantly associated with higher coliform levels: agricultural land and urban areas. In the context of this assessment, the Landsat-5 sensor offered the best cost-benefit ratio. CONCLUSION: Satellite imagery can be used to identify environmental factors associated with a higher risk of fecal contamination of recreational waters in Canada and may supplement current monitoring and risk assessment efforts.

Agroenvironmental determinants associated with the presence of antimicrobial-resistant Escherichia coli in beach waters in Quebec, Canada.

Exposure to microorganisms resistant to antimicrobials may constitute a health risk to human populations. It is believed that one route of exposure occurs when people engage in recreational activities in water contaminated with these microorganisms. The main objective of this study was to explore population-level and environmental determinants specifically associated with the presence of antimicrobial resistant (AMR) generic Escherichia coli isolated from recreational waters sampled from beaches located in southern Quebec, Canada. Water samples originated from the Quebec provincial beach surveillance program for the summers of 2004 and 2005. This study focused on three classes of determinants, namely: agricultural, population-level and beach characteristics for a total of 19 specific factors. The study was designed as a retrospective observational analysis and factors were assessed using logistic regression methods. From the multivariable analysis, the data suggested that the percentage of land used for spreading liquid manure was a significant factor associated with the presence of AMR E. coli (OR=27.73). Conceptually, broad factors potentially influencing the presence of AMR bacteria in water must be assessed specifically in addition to factors associated with general microbial contamination. Presence of AMR E. coli in recreational waters from beaches in southern Quebec may represent a risk for people engaging in water activities and this study provides preliminary evidence that agricultural practices, specifically spreading liquid manure in agricultural lands nearby beaches, may be linked to the contamination of these waters by AMR E. coli.

Trends in antimicrobial resistance among clinical isolates of the Bacteroides fragilis group from 1992 to 1997 in Montreal, Canada.

The objective of the present study was to analyze the susceptibility profiles of 911 clinical strains of the Bacteroides fragilis group isolated from 1992 to 1997 in our institution in order to monitor susceptibility changes over time. Whereas the rates of resistance to metronidazole, imipenem, piperacillin-tazobactam, ticarcillin-clavulanic acid, penicillin, piperacillin, and cefoxitin remained essentially unchanged, there was a significant increase in the rates of resistance to clindamycin, which rose from 8.2% in 1992 to 19.7% in 1997 (P < 0.0004).

Cefotaxime, desacetyl-cefotaxime, and bactericidal activity in spontaneous bacterial peritonitis.

We have prospectively studied 13 episodes of spontaneous bacterial peritonitis (SBP) in 12 patients treated with cefotaxime (CTX) 2 g intravenously every 8 h (mean duration, 5.3 days). Ascitic fluid was inoculated at the bedside. The cultures were done before, during (day 3 after CTX initiation), and 48-72 h (mean, 56 h) after the end of therapy. All SBP episodes were monomicrobial. During treatment, the concentrations of CTX and desacetyl-cefotaxime (d-CTX) in ascitic fluid were high in all 13 SBP episodes, and d-CTX was still present in 6 patients who had residual ascitic bactericidal titer (ABT) activity after the last dose of CTX. ABTs were >/=1:128 during CTX therapy in 12 episodes and were measurable in 7 patients after the last dose. All patients were cured. The present study provides scientific rationale to the clinical studies that suggest treating SBP episodes with lower doses of antibiotics and shorter treatment duration.

A complication of BCG vaccine: A case of localized cutaneous abscess due to Mycobacterium bovis.

The attenuated bacille Calmette-Guérin (BCG) vaccine is administered to prevent tuberculosis. Complications of vaccination are uncommon. A case of cutaneous abscess due to BCG is presented in a 24-year-old woman. The abscess developed at the inoculation site four weeks after vaccination. Routine Gram stain and bacterial cultures of the pus were negative. The auramine stain was positive. Mycobacterial cultures were positive after 14 and 18 days, using the BACTEC 12B bottle and Löwenstein-Jensen media, respectively. The mycobacteria were identified as Mycobacterium bovis, vaccinal strain by high-performance liquid chromatography and DNA probe assays.

Clindamycin resistance in the Bacteroides fragilis group: association with hospital-acquired infections.

A retrospective study was conducted to assess the relationships between clindamycin resistance in members of the Bacteroides fragilis group, previous antimicrobial therapy, and the context for the development of infection, whether in the community or during hospitalization. Eighty-five clindamycin-resistant clinical strains (one isolate per patient) isolated from January 1988 to October 1994 were matched (one to one) with clindamycin-susceptible isolates recovered during the same period, and the charts of the patients from whom the isolates were recovered were reviewed retrospectively. Of the clindamycin-resistant strains, 65% were recovered from patients with hospital-acquired infections compared with 40% of the clindamycin-susceptible strains (odds ratio [OR], 2.75; 95% confidence interval [CI], 1.41-5.38; P = .002). Prior antimicrobial therapy for > or = 48 hours was also associated with clindamycin resistance (OR, 2.33; 95% CI, 1.16-4.70; P = .02). However, clindamycin resistance remained associated with hospital-acquired infections independent of prior antimicrobial therapy (Mantel-Haenszel weighted average OR, 2.22; 95% CI, 1.03-4.89; P = .04). Clinicians should consider the risks for clindamycin resistance when treating hospital-acquired infections caused by members of the B. fragilis group.

Management of intra-abdominal infections. The case for intraoperative cultures and comprehensive broad-spectrum antibiotic coverage. The Canadian Intra-abdominal Infection Study Group.

OBJECTIVE: To test the hypothesis that comprehensive broad-spectrum empirical antimicrobial therapy is superior to limited-spectrum empirical antimicrobial therapy in intra-abdominal infections. DESIGN: Prospective, randomized, double-blinded study. SETTING: University-affiliated hospitals in Canada. PATIENTS: Two hundred thirteen patients with intra-abdominal infections and planned operative or percutaneous drainage. INTERVENTION: Limited-spectrum empirical antimicrobial therapy consisted of cefoxitin sodium, 2 g, intravenously, every 6 hours (n = 109). Comprehensive broad-spectrum empirical antimicrobial therapy consisted of a combination of imipenem and cilastatin sodium, 500 mg, intravenously, every 6 hours (n = 104). MAIN OUTCOME MEASURES: Failure to cure the intra-abdominal infection (persistence of infection or death). RESULTS: Of initial isolates, 98% were sensitive to imipenem plus cilastin sodium compared with 72% for cefoxitin. No difference was found in the failure rate between treatment groups. Among various reasons for failure (including technical), 12 of 80 patients in the limited-spectrum empirical antimicrobial therapy group had resistant organisms at a second intervention compared with 1 of 74 in the comprehensive broad-spectrum empirical antimicrobial therapy group (P < .003, chi 2). One death in the limited-spectrum empirical antimicrobial therapy group was due to autopsy-proved disseminated Pseudomonas aeruginosa (blood, peritoneum, lung, and pleural fluid) that was resistant to cefoxitin, and the other was associated with peritonitis due to cefoxitin-resistant Enterobacter cloacae. One death in the comprehensive broad-spectrum empirical antimicrobial therapy group was associated with peritonitis from Clostridium perfringens that was sensitive to imipenem plus cilastin sodium, and the other was associated with peritonitis from Pseudomonas aeruginosa that was resistant to imipenem plus cilastin sodium. CONCLUSION: Treatment failure of intra-abdominal infection may be due, in part, to the presence of resistant pathogens at the site of infection. Therefore, routine culture of these sites seems worthwhile and empirical therapy should be as comprehensive as possible and should cover all potential pathogens.

Focal myositis presenting as pseudothrombophlebitis of the neck in a patient with mixed connective tissue disease.

This report describes a case of focal myositis in a patient with mixed connective tissue disease. The patient presented with diffuse neck swelling and pseudothrombophlebitis of the left internal jugular vein. Other clinical features included a high fever, elevated erythrocyte sedimentation rate, and prompt improvement after administration of high-dose intravenous corticosteroid therapy. Criteria for polymyositis were absent, serum levels of creatine kinase remained normal, and there was no sign of recurrence during 3 years of followup. Results of immunoprecipitation for anti-Jo-1 and other myositis-specific autoantibodies remained negative in serial serum samples obtained before, during, and after the episode.

Pneumococcal resistance to antimicrobial agents in the province of Québec, Canada.

The serogroup/serotypes (SGTs) and antimicrobial susceptibilities to 10 antimicrobial agents of 110 clinical strains of Streptococcus pneumoniae were determined. Strains intermediately resistant or highly resistant to penicillin G (80 of 110) belonged predominantly to SGTs 23 (45.0%), 19 (13.7%), 6 (10.0%), 9 (6.2%), and 14 (3.7%). The MICs of all cephalosporins, tetracycline, trimethoprim-sulfamethoxazole, and chloramphenicol increased along with the MICs of penicillin G. However, erythromycin resistance and clindamycin resistance were observed more frequently among the intermediately penicillin-resistant strains. Multiple resistance was observed for 32 strains, of which 25 were highly resistant to penicillin G and belong to SGT 23F. All strains were susceptible to vancomycin.

Longitudinal study of susceptibilities of species of the Bacteroides fragilis group to five antimicrobial agents in three medical centers.

A total of 579 clinical isolates of the Bacteroides fragilis group collected from three Canadian hospitals were tested for susceptibility to five antimicrobial agents by using an agar dilution method. During the 4-year survey, isolates from intra-abdominal infections were collected from the following sites: abdominal abscesses (48%), peritoneal fluid (39%), blood (10%), and bile (3%). B. fragilis was the most prevalent species (35.4%), followed by B. thetaiotaomicron (19.2%), B. ovatus (15.9%), and B. vulgatus (11%). No metronidazole- or imipenem-resistant strains were found during the survey. Resistance profiles varied among the different species tested: 7.8, 2.9, and 7.3% of B. fragilis strains (n = 205) and 68.1, 17.2, and 9.4% of non-B. fragilis strains (n = 373) were resistant to cefotetan, cefoxitin, and clindamycin, respectively. B. fragilis and B. vulgatus demonstrated lower resistance rates than B. thetaiotaomicron, B. ovatus, B. distasonis, and B. caccae. During the study, rates of resistance to cefotetan and clindamycin fluctuated but rates of resistance to cefoxitin increased, particularly at one center. These data indicate a need to determine the susceptibility patterns of the B. fragilis group periodically at each hospital.

Comparison of single-dose cefotetan and multidose cefoxitin as intravenous prophylaxis in elective, open biliary tract surgery: a multicentre, double-blind, randomized study.

OBJECTIVE: To compare the safety, tolerance and prophylactic effectiveness of a single 2-g dose of cefotetan with a standard prophylactic regimen of cefoxitin in reducing the incidence of postoperative infections after elective, open biliary tract surgery. DESIGN: Multicentre, double-blind, randomized comparative study with a 4-week follow-up. SETTING: Five Canadian university centres. PARTICIPANTS: One hundred and eleven patients scheduled to undergo elective, open biliary tract surgery. INTERVENTIONS: The patients were randomly assigned to receive either cefotetan or cefoxitin in a ratio of 2:1; 76 patients received cefotetan and 35 received cefoxitin. MAIN OUTCOME MEASURES: Wound infection as defined by the Centers for Disease Control and Prevention and by clinical evaluation, adverse events and laboratory parameters. RESULTS: Two incisional wound infections were reported by patients in the cefotetan group, for an overall infection rate of 1.8% (2 of 111). No significant differences were found in the failure rate or in any other indicator of efficacy. The incidence of adverse events for cefotetan (12.6%) was not statistically different from that for cefoxitin (10.4%), and none of the 16 adverse events in the cefotetan group and 5 in the cefoxitin group was serious or severe. Only one event (rash) was possibly related to the study drugs. Several hematologic and biochemical parameters were found to be normal preoperatively and abnormal postoperatively, but no relation was found between these variations and the study drugs. These changes were mainly attributable to the operation. CONCLUSION: Cefotetan was found to be effective and comparable to cefoxitin, both in safety and in reducing the incidence of infection after elective, open biliary tract surgery.

Antimicrobial susceptibility of Streptococcus suis isolates.

The antimicrobial activities of penicillin (PEN), ampicillin (AMP), cephalothin (CT), trimethoprim-sulphamethoxazole (TMP-SMX), streptomycin (STM), and gentamicin (GM) against 122 representative strains of Streptococcus suis, were compared by the agar dilution procedure. The current US National Committee for Clinical Laboratory Standards (NCCLS) breakpoints for non-enterococcal streptococci were used for PEN, AMP, CT, and TMP-SMX. Overall, 50% of strains were not fully susceptible to PEN, whereas these percentages for AMP and CT were 9% and 6% respectively. One strain was resistant to TMP-SMX. High-level GM resistance could not be detected, but more than 46% of strains were highly resistant to STM (MIC > 2000 mg l-1). This high percentage of resistance to STM precludes the use of this aminoglycoside-penicillin combination as empiric therapy in severe S. suis infections. These results should prompt microbiology laboratories to carry out antimicrobial susceptibility tests on a routine basis on S. suis isolates.

Lambda light chain deposition disease presenting as an amyloid-like arthropathy.

We describe a case of lambda light chain deposition disease (LCDD) which presented with symmetric, seronegative, nonerosive arthritis associated with skin nodules and widespread, progressive soft tissue induration. Multiple biopsies disclosed Congo red nonbirefringent deposits which stained strongly with lambda light chain antiserum, allowing distinction from amyloid arthropathy. This is the first report of musculoskeletal involvement in LCDD.