Temporal analysis of acute myocardial infarction in Ontario, Canada

BACKGROUND: Acute myocardial infarction (AMI) is a substantial cause of morbidity and mortality in Canada. Evidence suggests that the incidence and mortality of AMI increase in the winter. Determining the strength and nature of seasonality patterns in relation to age and sex may be helpful in health care planning. OBJECTIVES: To examine the seasonal patterns of AMI hospital admissions by age and sex, to assess the strength of the seasonal patterns and to examine the overall trends in admissions. METHODS: A retrospective population-based study was conducted to assess temporal patterns in 14 years of hospital admissions for AMI (from April 1, 1988, to March 31, 2002) in Ontario. Seasonality was assessed using the autoregression coefficient (R2Autoreg), and Fisher's Kappa and Bartlett's Kolmogorov-Smirnov tests. RESULTS: There were 271,321 people in the cohort, of whom 63% (n = 171,546) were male and 37% (n = 99,775) were female. There was an increase in AMI admissions since 1988 that reached a plateau in 1992, which was attributable mostly to the increased rate in the oldest age groups (70 years and older), where admission rates more than doubled. An association between seasonality and AMI admissions was found in most age and sex groups, with men consistently exhibiting a stronger seasonality pattern. The greatest difference in the cohort, 2.5 per 100,000 per month (134 admissions), occurred between December and September (13.64 per 100,000 in September versus 16.14 per 100,000 in December). CONCLUSIONS: AMI admissions show seasonality patterns, which are more pronounced in men. Although statistically significant, the seasonal differences are small in terms of absolute numbers, and are likely irrelevant in health care planning.     

A novel method of surgical site infection surveillance after cardiac surgery by active participation of stake holders

We describe a comprehensive surveillance system involving infection control practitioners, surgeons, administrative staff, and patients aimed at improving the postdischarge surveillance of surgical site infections. The system was able to detect 22 infections out of 538 procedures, 95% of which were detected during the postdischarge period.     

The formation of an organic coat and the release of corrosion microparticles from metallic magnesium implants

Magnesium alloys have been proposed as prospective degradable implant materials. To elucidate the complex interactions between the corroding implants and the tissue, magnesium implants were analyzed in a mouse model and the response was compared to that induced by Ti and by the resorbable polymer polyglactin, respectively. One month after implantation, distinct traces of corrosion were apparent but the magnesium implants were still intact, whereas resorbable polymeric wound suture implants were already fragmented. Analysis of magnesium implants 2 weeks after implantation by energy-dispersive X-ray spectroscopy indicated that magnesium, oxygen, calcium and phosphate were present at the implant surface. One month after implantation, the element composition of the outermost layer of the implant was indicative of tissue without detectable levels of magnesium, indicating a protective barrier function of this organic layer. In agreement with this notion, gene expression patterns in the surrounding tissue were highly similar for all implant materials investigated. However, high-resolution imaging using energy-filtered transmission electron microscopy revealed magnesium-containing microparticles in the tissue in the proximity of the implant. The release of such corrosion particles may contribute to the accumulation of calcium phosphate in the nearby tissue and to bone conductive activities of magnesium implants.     

Aspergillosis in a gyrfalcon (Falco rusticolus) in Saudi Arabia

A mixed case of chronic tracheal (syringeal) and pulmonary (lungs and air sacs) aspergillosis was diagnosed in an adult female gyrfalcon (Falco rusticolus). The bird presented with a 4-week history of severe dyspnea, exercise intolerance, depression and reduced appetite. Physical examination revealed slight emaciation. Hematological analysis showed leucocytosis, heterophilia, monocytosis, and thrombocytosis. Radiographic examination showed thickening of the air sac walls and increased radiopacity within the lung field. Caseous granulomatous lesions were observed during tracheoscopy and laparoscopy procedures. Cytological examination of specimens obtained from these lesions demonstrated Aspergillus species, which was isolated in culture and identified as Aspergillus flavus.     

An MRI scale for assessment of haemophilic arthropathy from the International Prophylaxis Study Group

Evaluation of prophylactic treatment of haemophilia requires sensitive methods. To design and test a new magnetic resonance imaging (MRI) scale for haemophilic arthropathy, two scales of a combined MRI scoring scheme were merged into a single scale which includes soft tissue and osteochondral subscores. Sixty‐one joint MRI's of 46 patients with haemophilia were evaluated by four radiologists using the new and older scales. Forty‐six of the joints were evaluated using two X‐ray scales. For all MRI scores, interreader agreement and correlations with X‐ray scores and lifetime number of haemarthroses were analysed. The interreader agreement intraclass correlation coefficient was 0.82, 0.89 and 0.88 for the soft tissue and osteochondral subscores and the total score, as evaluated according to the new MRI scale, compared to 0.80 and 0.89 as for the older scales. The total score and osteochondral subscore according to the new scale, as well as scores according to the older scales were correlated (P < 0.01) with number of haemarthroses (Spearman correlation 0.35–0.68) and with the X‐ray scores (Spearman correlation 0.40–0.76), but no correlation (P > 0.05) was found between the soft tissue subscore of the new MRI scale and the X‐ray scores. The new MRI scale is simpler to apply than the older and has similar reader reliability and correlation with lifetime number of haemarthroses, and by separating soft tissue and osteochondral changes it gives additional information. The new scale is useful for analyses of early and moderate stages of arthropathy, and may help to evaluate prophylactic haemophilia treatment.