Hydatid Disease in Toronto

Two case reports of Echinococcus granulosus disease are presented in detail, together with a survey of 35 cases of the disease encountered in Toronto hospitals since 1932; 32 of these have occurred since 1949. Only six of the 35 patients were born in and lived in Canada, and all of these came from Northern Ontario. The liver was involved in 20 of the 35 patients, and the lung in 16. In seven the lesions were multiple at the time of the first operation or several years later. The Casoni skin test was positive in 14 of 21 patients tested and the complement fixation test was positive in 13 of 16 subjects tested. Eosinophilia of 6% or more occurred in nine of the 26 patients on whom a differential white blood cell count was performed, and allergic manifestations were recorded in eight of the 35 subjects in the series.     

Effect of light intensity on sporulation of Botryosphaeria ribis

Pycnidia were produced by six of seven isolates ofB. ribis at one or more intensity levels of continuous illumination at 21 °C. Under conditions of alternating light (12 h–27 °C) and darkness (12 h–21 °C) pycnidia formed in cultures of six isolates at three or more intensity levels, while one isolate failed to form pycnidia at any intensity level. Pycnidia did not develop when cultures were incubated in complete darkness. Exposure periods as brief as 2 days under continuous illumination at 21 °C induced pycnidial formation. In alternating light (12 h–27 °C) and darkness (12 h–21 °C), the shortest period of exposure which induced pycnidial formation was 4 days. Continuous illumination at 21 °C favored development of uniloculate pycnidia, while alternating light (12 h–27 °C) and darkness (12 h–21 °C) favored formation of multiloculate pycnidia.Contribution No. 22 from The Botany Section of The Department of Biology, The Pennsylvania State University.     

Evolution of the Lactic Acid Bacterial Community during Malt Whisky Fermentation: a Polyphasic Study

The development of the lactic acid bacterial community in a commercial malt whisky fermentation occurred in three broad phases. Initially, bacteria were inhibited by strong yeast growth. Fluorescence microscopy and environmental scanning electron microscopy revealed, in this early stage, both cocci and rods that were at least partly derived from the wort and yeast but also stemmed from the distillery plant. Denaturing gradient gel electrophoresis (DGGE) of partial 16S rRNA genes and sequence analysis revealed cocci related to Streptococcus thermophilus or Saccharococcus thermophilus, Lactobacillus brevis, and Lactobacillus fermentum. The middle phase began 35 to 40 h after yeast inoculation and was characterized by exponential growth of lactobacilli and residual yeast metabolism. Lactobacillus casei or Lactobacillus paracasei, L. fermentum, and Lactobacillus ferintoshensis were detected in samples of fermenting wort examined by DGGE during this stage. Bacterial growth was accompanied by the accumulation of acetic and lactic acids and the metabolism of residual maltooligosaccharides. By 70 h, two new PCR bands were detected on DGGE gels, and the associated bacteria were largely responsible for the final phase of the fermentation. The bacteria were phylogenetically related to Lactobacillus acidophilus and Lactobacillus delbrueckii, and strains similar to the former had previously been recovered from malt whisky fermentations in Japan. These were probably obligately homofermentative bacteria, required malt wort for growth, and could not be cultured on normal laboratory media, such as MRS. Their metabolism during the last 20 to 30 h of fermentation was associated with yeast death and autolysis and further accumulation of lactate but no additional acetate.     

Creating multithemed ecological regions for macroscale ecology: Testing a flexible,repeatable, and accessible clustering method

Understanding broad‐scale ecological patterns and processes often involves accounting for regional‐scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question—How well do these regions capture regional‐scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km²); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft‐ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation—approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional scale. Our results demonstrate the usefulness of this method for creating customizable and reproducible regions for research and management applications.     

Effects of OSA, inhalational anesthesia, and fentanyl on the airway and ventilation of children.

To assess effects of anesthesia and opioids, we studied 13 children with obstructive sleep apnea (OSA, age 4.0 +/- 2.2 yr, mean +/- SD) and 24 age-matched control subjects (5.8 +/- 4.0 yr). Apnea indexes of children with OSA were 29.4 +/- 18 h-1, median 30 h-1. Under inhalational anesthetic, closing pressure at the mask was 2.2 +/- 6.9 vs. -14.7 +/- 7.8 cmH2O, OSA vs. control (P < 0.001). After intubation, spontaneous ventilation was 115.5 +/- 56.9 vs. 158.7 +/- 81.6 ml x kg-1 small middle dot min-1, OSA vs. control (P = 0.02), despite elevated PCO2 (49.3 vs. 42.1 Torr, OSA vs. control, P < 0.001). Minute ventilation fell after fentanyl (0.5 microg/kg iv), with central apnea in 6 of 13 OSA cases vs. 1 of 23 control subjects (P < 0.001). Consistent with the finding of reduced spontaneous ventilation, apnea was most likely when end-tidal CO2 exceeded 50 Torr during spontaneous breathing under anesthetic. Thus children with OSA had depressed spontaneous ventilation under anesthesia, and opioids precipitated apnea in almost 50% of children with OSA who were intubated but breathing spontaneously under inhalational anesthesia.     

Dietary selenium levels determine epidermal langerhans cell numbers in mice

Selenium (Se) is a dietary trace element that is essential for effective immunity and protection from oxidative damage induced by ultraviolet radiation (UVR). Langerhans cells (LC) represent the major antigen-presenting cells resident in the epidermis; a proportion migrate from the skin to the draining lymph nodes in response to UVR. Because it is known that Se deficiency impairs immune function, we determined what effect this has on LC numbers. CH3/HeN mice were weaned at 3 wk and placed on diets containing <0.005 ppm of Se (Se deficient) or 0.1 ppm of Se (Se adequate, control mice). After 5 wk on the diet, the epidermal LC numbers in the Se-adequate group were 966±51 cells/mm² and LC counts in the epidermis of the Se-deficient mice were 49% lower (p<0.05). Glutathione peroxidase-I (GPx) activity was measured in the epidermis, lymph nodes, and liver. In the epidermis, the activity of GPx in the Se-deficient mice was only 39% (p<0.01) of that seen in epidermis from Se-adequate mice (1.732 U/mg protein). The mice were then irradiated with one dose of 1440 J/m² of broadband UVB or mock irradiated. After 24 h, the decrease in LC number after UVB was greater in the Se-adequate mice, (40% decrease) compared to the Se-deficient group (10%). Thus, Se deficiency reduces epidermal LC numbers, an effect that might compromise cutaneous immunity.     

A Bifidobacterial pilus‐associated protein promotes colonic epithelial proliferation

Development of the human gut microbiota commences at birth, with certain bifidobacterial species representing dominant and early colonisers of the newborn gastrointestinal tract. The molecular basis of Bifidobacterium colonisation, persistence and presumed communication with the host has remained obscure. We previously identified tight adherence (Tad) pili from Bifidobacterium breve UCC2003 as an essential colonisation factor. Here, we demonstrate that bifidobacterial Tad pili also promote in vivo colonic epithelial proliferation. A significant increase in cell proliferation was detectable 5 days postadministration of B. breve UCC2003. Using advanced functional genomic approaches, bacterial strains either (a) producing the Tad₂₀₀₃ pili or (b) lacking the TadE or TadF pseudopilins were created. Analysis of the ability of these mutant strains to promote epithelial cell proliferation in vivo demonstrated that the pilin subunit, TadE, is the bifidobacterial molecule responsible for this proliferation response. These findings were confirmed in vitro using purified TadE protein. Our data imply that bifidobacterial Tad pili may contribute to the maturation of the naïve gut in early life through the production of a specific scaffold of extracellular protein structures, which stimulate growth of the neonatal mucosa.     

A systematic genetic assessment of 1,433 sequence variants of unknown clinical significance in the BRCA1 and BRCA2 breast cancer-predisposition genes

Mutation screening of the breast and ovarian cancer-predisposition genes BRCA1 and BRCA2 is becoming an increasingly important part of clinical practice. Classification of rare nontruncating sequence variants in these genes is problematic, because it is not known whether these subtle changes alter function sufficiently to predispose cells to cancer development. Using data from the Myriad Genetic Laboratories database of nearly 70,000 full-sequence tests, we assessed the clinical significance of 1,433 sequence variants of unknown significance (VUSs) in the BRCA genes. Three independent measures were employed in the assessment: co-occurrence in trans of a VUS with known deleterious mutations; detailed analysis, by logistic regression, of personal and family history of cancer in VUS-carrying probands; and, in a subset of probands, an analysis of cosegregation with disease in pedigrees. For each of these factors, a likelihood ratio was computed under the hypothesis that the VUSs were equivalent to an "average" deleterious mutation, compared with neutral, with respect to risk. The likelihood ratios derived from each component were combined to provide an overall assessment for each VUS. A total of 133 VUSs had odds of at least 100 : 1 in favor of neutrality with respect to risk, whereas 43 had odds of at least 20 : 1 in favor of being deleterious. VUSs with evidence in favor of causality were those that were predicted to affect splicing, fell at positions that are highly conserved among BRCA orthologs, and were more likely to be located in specific domains of the proteins. In addition to their utility for improved genetics counseling of patients and their families, the global assessment reported here will be invaluable for validation of functional assays, structural models, and in silico analyses.