A case report of an unusual mycotic pseudoaneurysm of the ascending aorta.

BACKGROUND: Mycotic pseudoaneurysms of the ascending aorta are a rare and devastating complication of previous cardiac surgery. CASE PRESENTATION: We present an unusual case of a fungal mycotic pseudoaneurysm secondary to an aortic suture line successfully repaired under deep hypothermic circulatory arrest. CONCLUSIONS: Patients with mycotic pseudoaneurysms of the aorta require a multidisciplinary team approach to prevent devastating complications that may occur in these complex surgical cases.

Acute tracheal tear - A potential cause of spontaneous pneumomediastinum in patients with COVID-19.

Spontaneous pneumomediastinum following prolonged periods of severe coughing should raise the suspicion of tracheal rupture in COVID-19 patients.

Prospective evaluation of unmet needs of rural and aboriginal cancer survivors in Northern British Columbia.

BACKGROUND: The unmet needs of cancer survivors in rural, remote, and aboriginal communities are largely unexplored. We explored potential differences between rural survivors (rss) in 4 general population (gp) and 4 First Nations (fn) communities. METHODS: We approached 4 gp and 4 fn rs communities to participate in a mixed-methods project. Participants completed the Hospital Anxiety and Depression Scale (hads) and the Survivor Unmet Needs Survey (suns) and provided demographic information. Each question on the suns can be scored from 0 to 4, with 0 representing "no unmet need" and 4 representing "very high unmet need." A directed approach to content analysis of focus group and interview data was used to triangulate the hads and suns results. RESULTS: We prospectively accrued 23 fn rss and 56 gp rss for this study. More fn rss had borderline or abnormal anxiety (5% vs. 21%, p = 0.02). Compared with gp rss, fn rss had higher unmet needs scores in all categories: Information (2.29 vs. 0.8, p < 0.001), Work and Financial (1.66 vs. 0.5, p < 0.001), Access and Continuity of Health Care (1.83 vs. 0.44, p < 0.001), Coping and Sharing (2.22 vs. 0.62, p < 0.001), and Emotional (2.12 vs. 0.63, p < 0.001). The qualitative findings provided examples and insight into the unmet needs experienced by rss. CONCLUSIONS: First Nations rss had significantly higher anxiety and unmet needs compared with their gp rs counterparts. In addition, different qualitative themes were identified in the groups. Our findings support the development of tailored approaches to survivorship for these populations.

Interpretation of gypsy moth frontal advance using meteorology in a conditional algorithm.

The gypsy moth, Lymantria dispar, is a non-native species that continues to invade areas in North America. It spreads generally through stratified dispersal where local growth and diffusive spread are coupled with long-distance jumps ahead of the leading edge. Long-distance jumps due to anthropogenic movement of life stages is a well-documented spread mechanism. Another mechanism is the atmospheric transport of early instars and adult males, believed to occur over short distances. However, empirical gypsy moth population data continue to support the possibility of alternative methods of long-range dispersal. Such dispersal events seemed to have occurred in the mid- to late-1990s with spread across Lake Michigan to Wisconsin. Such dispersal would be against the prevailing wind flow for the area and would have crossed a significant physical barrier (Lake Michigan). The climatology of the region shows that vigorous cyclones can result in strong easterly winds in the area at the time when early instars are present. It is hypothesized that these storms would enable individuals to be blown across the Lake and explain the appearance of new population centers observed at several locations on the western shore of Lake Michigan nearly simultaneously. A synoptic climatology model coupled with population dynamics data from the area was parameterized to show an association between transport events and population spread from 1996 to 2007. This work highlights the importance of atmospheric transport events relative to the invasion dynamics of the gypsy moth, and serves as a model for understanding this mechanism of spread in other related biological invasions.

Critical patch size generated by Allee effect in gypsy moth, Lymantria dispar (L.).

Allee effects are important dynamical mechanisms in small-density populations in which per capita population growth rate increases with density. When positive density dependence is sufficiently severe (a 'strong' Allee effect), a critical density arises below which populations do not persist. For spatially distributed populations subject to dispersal, theory predicts that the occupied area also exhibits a critical threshold for population persistence, but this result has not been confirmed in nature. We tested this prediction in patterns of population persistence across the invasion front of the European gypsy moth (Lymantria dispar) in the United States in data collected between 1996 and 2008. Our analysis consistently provided evidence for effects of both population area and density on persistence, as predicted by the general theory, and confirmed here using a mechanistic model developed for the gypsy moth system. We believe this study to be the first empirical documentation of critical patch size induced by an Allee effect.

Type 2 diabetes in the First Nations population: a case example of clinical practice guidelines.

CONTEXT: Type 2 diabetes (T2D) is a major public health concern and has reached epidemic proportions in the Canadian First Nation population. Reasons for this epidemic are the consequences of low socioeconomic status, and challenges to screening, primary prevention, management and access to care. ISSUE: This article presents the authors' opinions of the healthcare needs specific to the First Nation population in Canada with respect to management of T2D. LESSONS LEARNED: The authors argue that the current Canadian Diabetes Association Clinical Practice Guidelines are insufficient to provide a basis for health care and funding policies related to T2D management in the First Nation population. The authors present their own recommendations in relation to funding policies and the appropriateness of services for the First Nation population.

Dispersion in time and space affect mating success and Allee effects in invading gypsy moth populations.

1. Understanding why invading populations sometimes fail to establish is of considerable relevance to the development of strategies for managing biological invasions. 2. Newly arriving populations tend to be sparse and are often influenced by Allee effects. Mating failure is a typical cause of Allee effects in low-density insect populations, and dispersion of individuals in space and time can exacerbate mate-location failure in invading populations. 3. Here we evaluate the relative importance of dispersal and sexual asynchrony as contributors to Allee effects in invading populations by adopting as a case study the gypsy moth (Lymantria dispar L.), an important insect defoliator for which considerable demographic information is available. 4. We used release-recapture experiments to parameterize a model that describes probabilities that males locate females along various spatial and temporal offsets between male and female adult emergence. 5. Based on these experimental results, we developed a generalized model of mating success that demonstrates the existence of an Allee threshold, below which introduced gypsy moth populations are likely to go extinct without any management intervention.

An analysis of opinions from veterinarians in South Africa regarding business management skills.

The changing role of veterinarians in the global market is a current topic of debate and discussion. Few countries including South Africa have formally examined the changing dynamics of this profession. Therefore, the present study addressed 2 objectives. The 1st was to examine basic information about veterinarians in South Africa including their age, gender and distribution across provinces, the percentage whose practice was urban, rural or periurban, the numbers working with specific animal species, and the extent of business management and skills previously gained. The 2nd objective was to obtain opinions and insights from veterinarians in South Africa about the challenges and opportunities facing their business practices to better understand what they considered important dynamics to their businesses today. Several areas of business on which they were questioned and which were included in this study were: marketing, vision, human resources, leadership, financial management, ethics, competition, day-to-day operations, interpersonal skills and information management. This is the 1st known survey to employ a questionnaire to gain insights and opinions from veterinarians about business management skills.

Grape cane gallmaker (Coleoptera: Curculionidae) and its impact on cultivated grapes.

The grape cane gallmaker, Ampeloglypter sesostris (Leconte), is a native weevil that infests new shoots of wild and cultivated grapes (Vitis spp.). Females oviposit on the tender portions of new shoots, producing a reddish gall that can expand the shoot to twice its normal diameter. These galls can be quite numerous in eastern vineyards, and their effects are unknown. We studied the spatial distribution of grape cane gallmaker and its impact on berry size, sugar content, and nutrient and mineral uptake. We observed spatial trends in grape cane gallmaker distribution in vineyards adjacent to woodland margins, with the trend emanating from the woodline. In vineyards without woodland margins, there was little spatial dependency in grape cane gallmaker distribution in individual years. However, grape cane gallmaker density on a single vine was spatially cross-correlated between 2 yr. The presence of galls did not significantly affect berry quality, or the uptake of nutrients and minerals, and we conclude that grape cane gallmaker does not negatively impact berry quality or mature vine vigor.

Reservoir competence of Carcinops pumilio for Salmonella enteritidis (Eubacteriales: Enterobacteriaceae).

The histerid beetle Carcinops pumilio (Erichson) occurs naturally in poultry house manure and is an important predator of house fly eggs and larvae. Because efforts to commercially produce C. pumilio have been unsuccessful, one fly control strategy under consideration is the direct transport of adult C. pumilio between poultry houses to facilitate their establishment. However, we demonstrate that C. pumilio is a competent reservoir of Salmonella enteritidis (Gaertner). Adult C. pumilio exposed to S. enteritidis-inoculated house fly eggs harbored the bacterium externally and internally for up to 4 and 13 d, respectively, and feces were culture-positive for S. enteritidis for at least 14 d. This suggests that C. pumilio can be a reservoir of S. enteritidis; therefore its movement between poultry facilities should be carefully considered.

Spatio-temporal dynamics of resident and immigrating populations of Carcinops pumilio (Coleoptera: Histeridae) in high-rise poultry facilities.

The histerid beetle Carcinops pumilio (Erichson) is an important natural predator of the house fly, Musca domestica L., in accumulated poultry house manure. We examined the spatio-temporal dynamics of establishing adult C. pumilio in high-rise poultry facilities using conventional and geostatistical approaches. The growth curves of resident and immigrating populations followed logistic and exponential equations, respectively, and their rates of establishment were statistically the same. Frequency distributions for both populations were strongly positively skewed, and approximately 53% of sampling intervals were significantly modeled by the negative binomial. Taylor's power law indicated both populations to be aggregated, and gave excellent least squares regression fits to both populations. Correlograms, a geostatistical tool, suggested little local spatial structure (e.g., 2nd order effects) for either population. The resident population was 'randomly' aggregated: beetles were clustered around randomly distributed aggregations of house fly immatures. The immigrating population exhibited significant spatial trends (e.g., 1st order effects) consistently seen at all sampling intervals. C. pumilio spatial structure was represented primarily by this spatial trend; thus, immigration of C. pumilio may have been either a singular event in time, or initiating at 1 or multiple times from a singular location.

Flotation method for extracting insects from poultry manure samples.

We examined the efficacy of a sucrose-based flotation method for extracting 3 prevalent insect species from poultry house manure: 3rd-instar Musca domestica L. (Diptera: Muscidae), Carcinops pumilio (Erichson) (Coleoptera: Histeridae) adults, and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) adults. A 0.6 M sucrose solution in distilled water altered the specific gravity to 1.2 and caused the 3 species to float to the water surface for easy separation. An analysis of variance (ANOVA) showed significant effects of the solution volume to sample mass ratio on recovery rates (F = 35.96, P < 0.0001), but no differences in species-specific recovery rates (F = 0.97, P = 0.3824). Among samples agitated in a ratio of at least 3.2 ml solution per gram of sample mass, we observed neither significant ratio effects (F = 1.37, P = 0.2442) nor significant differences in species-specific recovery rates (F = 2.05, P = 0.1353); overall, we recovered 97.49 +/- 0.20% of all individuals of the 3 species. Our analyses demonstrated that sucrose-based flotation was a statistically valid method of collecting these species from poultry manure samples.

Effect of physiological conditions on the autolysis of Staphylococcus aureus strains.

The effect of physiological conditions on autolysis and autolytic activity in various strains of Staphylococcus aureus was determined. The rate of whole cell autolysis of S. aureus was growth phase dependent and a maximum rate was observed in early stationary phase cultures. However, the autolysins extracted by the freeze-thaw method (cell-wall bound autolytic activity) did not show any significant increase in activity. The addition of NaCl to the growth medium enhanced the rate of autolysis with the highest rate being displayed by cultures grown in 1.5 M NaCl. However, lower autolytic activity was found in the freeze-thaw extracts of cultures grown at higher concentrations of NaCl. The rate of autolysis of cultures grown at 30 degrees C was higher than cultures grown at 37 or 43 degrees C. Thus, the rate of autolysis seems to be independent of the bacterial growth rate. Cultures grown in slightly acidic conditions showed a faster rate of autolysis compared to cultures grown under alkaline conditions. SDS-polyacrylamide gel containing 0.2% crude cell-wall of S. aureus did not show any obvious correlation with the appearance of any particular lytic band in the zymogram to autolytic activity or rate of autolysis of cultures grown under various environmental conditions. A nonhemolytic phenotype, mutations in the accessory gene regulator, and lysogeny (phages phi 11, phi 12, phi 13) had no obvious effect either on the rate of autolysis or on the pattern of lytic bands in the zymograms.

Effect of inhalation of 30% nitrous oxide on spectral components of heart rate variability in conscious man.

1. Periodicities in cardiac interbeat interval may be resolved into discrete frequency components by applying Fourier analysis to heart rate time series. Low-frequency components (< 0.15 Hz) are believed to be under parasympathetic and sympathetic control, whereas a higher frequency component in phase with respiration is believed to be entirely parasympathetic. The ratio of the power in the low-/high-frequency spectrum gives an estimate of sympathetic/parasympathetic balance. 2. This study examined, using heart rate variability spectral analysis, the cardiac autonomic effects of breathing 30% N2O in normal subjects. While supine, the inhalation of N2O caused a significant fall in high-frequency power and a rise in the low-/high-frequency spectrum. During air breathing, tilting caused a significant rise in the mean blood pressure, heart rate, low-frequency power and low-/high-frequency spectrum. During N2O breathing, tilting caused a rise in the heart rate and the mean blood pressure, but no significant alteration in the power of individual spectral components. During tilting, the heart rate, the low-frequency and low-/high-frequency spectrum were less when breathing N2O than when breathing air. 3. These observations are consistent with the effect of N2O being an enhanced sympathetic balance of sinoatrial control, with the primary effect being through reduced parasympathetic tone. Enhanced sympathetic dominance of heart rate variability was seen on standing while subjects breathed air, but this effect was blunted with N2O.

Isolation and characterization of autolysis-defective mutants of Staphylococcus aureus created by Tn917-lacZ mutagenesis.

Two autolysis-defective mutants (Lyt-1 and Lyt-2) of Staphylococcus aureus have been isolated by transposon Tn917-lacZ mutagenesis. The mutants exhibited normal growth rate, cell division, cell size, and adaptive responses to environmental changes. No autolytic activities were detected in a crude autolytic enzyme preparation from the Lyt- mutants. The rate of autolysis of whole cells and cell walls in the mutants were negligible, but mutant cell wall preparations were degraded by crude enzyme preparations from the wild-type strain. Zymographic analyses of enzyme extracts from the mutants showed a single autolytic enzyme band, compared with more than 10 autolytic enzyme bands from the parent strain. Analyses of intracellular and exoprotein fractions gave results similar to those in experiments with total-cell extracts. Southern blot analysis indicated the insertion of a single copy of the transposon into the chromosome of Lyt mutants. Isogenic Lyt mutants constructed by phage phi 11 transduction showed similar phenotypes. Because both Lyt- mutants had Tn917-lacZ inserted in the appropriate orientation, it was possible to determine gene activity under various conditions by measuring beta-galactosidase activity. The gene activity was found to be induced by low pH, low temperature, and high sucrose and high sodium chloride concentrations. From these data, we propose that the mutation lies in either a master regulatory gene or a structural gene which is responsible for the synthesis or processing of a majority of the autolytic enzyme bands.

Hypertension and cerebral arteries: relationship to disruption of the blood-brain barrier.

This study was performed to determine whether structural changes in cerebral arterioles could account for differences in susceptibility of the blood-brain barrier to acute hypertensive disruption between hypertensive and normotensive animals. We studied spontaneously hypertensive rats (SHR), 3 other models of hypertension and their normotensive controls. The age and duration of hypertension of the rats were matched to an earlier study showing that protection of the blood-brain barrier was usually found in rats with chronic hypertension. We measured the dimensions of fixed pial arterioles and minimal cerebrovascular resistance produced by bicuculline. Minimal cerebrovascular resistance was not different between the groups of animals. There were no differences in the area of the media of pial arterioles between any of the groups. In addition, we examined the possibility that sympathetic nerves might affect cerebrovascular resistance during bicuculline in SHR. The presence of sympathetic nerves in SHR, but not WKY, reduced the degree of cerebral vascular dilation during bicuculline. From these data we conclude that 1) structural changes in cerebral vessels do not account for protection of the blood-brain barrier in rats with a moderate duration of hypertension and 2) sympathetic nerves may have an exaggerated effect on cerebral vessels of SHR.