Vancomycin-Variable Enterococcal Bacteremia.

Vancomycin-variable enterococcus (VVE) is an emerging pathogen. VVE isolates initially appear phenotypically susceptible to vancomycin but possesses the vanA gene and can develop in vitro and in vivo resistance to vancomycin. We report a case of VVE bacteremia and describe how VVE poses diagnostic and therapeutic dilemmas.

Targeted amplification-based whole genome sequencing of Monkeypox virus in clinical specimens.

IMPORTANCE: We present a protocol to efficiently sequence genomes of the MPXV-causing mpox. This enables researchers and public health agencies to acquire high-quality genomic data using a rapid and cost-effective approach. Genomic data can be used to conduct surveillance and investigate mpox outbreaks. We present 91 mpox genomes that show the diversity of the 2022 mpox outbreak in Ontario, Canada.

Presence of left atrial diverticula, accessory appendages, and normal variant pulmonary venous anatomy diagnosed using MDCT and adverse outcomes following radiofrequency catheter ablation therapy in patients with drug-refractory atrial fibrillation: an exploratory study.

AIM: To determine the frequency of normal variation left atrial anatomy (NVLAA) (diverticula, accessory appendages) and normal variation pulmonary venous anatomy (NVPVA) in patients with atrial fibrillation (AF), and to determine whether the presence of these entities is associated with an increased recurrence of atrial arrhythmias following radiofrequency catheter ablation (RFCA). MATERIALS AND METHODS: All cardiac MDCT images performed prior to RFCA between November 2009 and May 2011 in patients with drug-refractory AF were retrospectively evaluated. The presence, type, and location of NVLAA and NVPVA, and outcome of RFCA were recorded. Success was defined as restoration of sinus rhythm. RESULTS: Forty-six consecutive patients with a mean age of 59.8 (±9.7) years (76.1% male) underwent cardiac MDCT for anatomical planning prior to RFCA procedures. Fourteen (30.4%) patients had NVLAA, 35% of patients had NVPVA. Thirty (65%) patients had successful RFCA: 57% of these had a NVLAA, 67% had NVPVA. Sixteen (35%) patients had unsuccessful RFCA: 63% of these had a NVLAA, 56% had NVPVA. There was no significant association between the presence of NVLAA (p = 0.699), NVPVA (p = 0.197), or "NVLAA in the presence of normal pulmonary venous anatomy" (p = 0.589) and the outcome of RFCA. CONCLUSION: The presence of NVLAA and NVPVA appears unrelated to adverse outcome in patients undergoing RFCA for the treatment of drug-refractory AF.

Organoid microphysiological system preserves pancreatic islet function within 3D matrix.

Three-dimensional (3D) multicellular organoids recapitulate the native complexities of human tissue better than traditional cellular monolayers. As organoids are insufficiently supported using standard static culture, microphysiological systems (MPSs) provide a key enabling technology to maintain organoid physiology in vitro. Here, a polydimethylsiloxane-free MPS that enables continuous dynamic culture and serial in situ multiparametric assessments was leveraged to culture organoids, specifically human and rodent pancreatic islets, within a 3D alginate hydrogel. Computational modeling predicted reduced hypoxic stress and improved insulin secretion compared to static culture. Experimental validation via serial, high-content, and noninvasive assessments quantitatively confirmed that the MPS platform retained organoid viability and functionality for at least 10 days, in stark contrast to the acute decline observed overnight under static conditions. Our findings demonstrate the importance of a dynamic in vitro microenvironment for the preservation of primary organoid function and the utility of this MPS for in situ multiparametric assessment.

Evaluating the use of whole genome sequencing for the investigation of a large mumps outbreak in Ontario, Canada.

In 2017 Ontario experienced the largest mumps outbreak in the province in 8 years, at a time when multiple outbreaks were occurring across North America. Of 259 reported cases, 143 occurred in Toronto, primarily among young adults. Routine genotyping of the small hydrophobic gene indicated that the outbreak was due to mumps virus genotype G. We performed a retrospective study of whole genome sequencing of 26 mumps virus isolates from early in the outbreak, using a tiling amplicon method. Results indicated that two of the cases were genetically divergent, with the remaining 24 cases belonging to two major clades and one minor clade. Phylogeographic analysis confirmed circulation of virus from each clade between Toronto and other regions in Ontario. Comparison with other genotype G strains from North America suggested that the presence of co-circulating major clades may have been due to separate importation events from outbreaks in the United States. A transmission network analysis performed with the software program TransPhylo was compared with previously collected epidemiological data. The transmission tree correlated with known epidemiological links between nine patients and identified new potential clusters with no known epidemiological links.

3-D physiomimetic extracellular matrix hydrogels provide a supportive microenvironment for rodent and human islet culture.

Organ-on-a-chip platforms serve as cost-efficient testbeds for screening pharmaceutical agents, mimicking natural physiology, and studying disease. In the field of diabetes, the development of an islet-on-a-chip platform would have broad implications in understanding disease pathology and discovering potential therapies. Islet microphysiological systems are limited, however, by their poor cell survival and function in culture. A key factor that has been implicated in this decline is the disruption of islet-matrix interactions following isolation. Herein, we sought to recapitulate the in vivo peri-islet niche using decellularized extracellular matrix (ECM) hydrogels. Sourcing from porcine bladder, lung, and pancreas tissues, 3-D ECM hydrogels were generated, characterized, and validated using both rodent and human pancreatic islets. Optimized decellularization protocols resulted in hydrogels with distinctive viscoelastic properties that correlated to their matrix composition. The in situ 3-D encapsulation of human or rat islets within ECM hydrogels resulted in improved functional stability over standard culture conditions. Islet composition and morphology were also altered, with enhanced retention of islet-resident endothelial cells and the formation of cord-like structures or sprouts emerging from the islet spheroid. These supportive 3-D physiomimetic ECM hydrogels can be leveraged within microfluidic platforms for the long-term culture of islets.

Lessons learnt from the Indian H1N1 (swine flu) epidemic: Predictors of outcome based on epidemiological and clinical profile.

INTRODUCTION: Influenza A (H1N1) virus has caused serious respiratory illness (swine flu) and death over the years. The first confirmed case of swine flu H1N1 in India was documented in May 2009, but huge numbers of cases were reported thereafter. In 2015, swine flu outbreak in India had led to significant morbidity and mortality. OBJECTIVE: to study details of swine flu patients admitted in a rural tertiary care center in western India in 2015 and to identify predictors of mortality. METHODOLOGY: Retrospective data of swine flu cases admitted at a tertiary care teaching hospital in 2015 and their outcome as either cured or expired was recorded. RESULT: Out of 65 confirmed cases of severe swine flu that required hospitalization, 40(61%) were male. 55 of 65 (84.61%) patients [mean (SD) age: 50(15)] were cured while 10 patients [mean (SD) age 51(15)] expired. Overall mean (SD) age was 50.23(15) years with average (SD) days of hospitalization were 6.32(3.3) days. The commonest symptoms were cough (100%) followed by throat pain (96.9%), common-cold, fever (93.8%), and breathlessness (83.1%). 40% of patients needed non invasive ventilator support while 16.9% patient required invasive ventilator. Mean temperature on presentation was (99.96'F), RR (25.89/min), SpO2 on room air was 82.06%. Average White Blood Cells were 8274/mm3 with neutrophils were 79.58%. Mean procalcitonin was 0.83 ng/ml. It was found through univariate analysis that sputum production (P = 0.013), chest pain (P = 0.04), Respiratory Rate (P = 0.013), SpO2 on presentation at room air (P = 0.001), Days of non invasive ventilator (P = 0.001), intubation and invasive ventilator (P = 0.001) were statistically significantly associated with outcome but through multivariate analysis it was revealed that only requirement of intubation (invasive ventilator) was significantly predicting mortality(Odds ratio=234) (P = 0.0001). CONCLUSION: Requirement of intubation was associated with poor outcome.

The continued rise of Lyme disease in Ontario, Canada: 2017.

BACKGROUND: Lyme disease is an infection caused by the spirochete Borrelia burgdorferi and, in most of North America, is transmitted by the blacklegged tick Ixodes scapularis. Climate change has contributed to the expansion of the geographic range of blacklegged ticks in Ontario, increasing the risk of Lyme disease for Ontarians. OBJECTIVE: To identify the number of cases and incidence rates, as well as the geographic, seasonal and demographic distribution of Lyme disease cases reported in Ontario in 2017, with comparisons to historical trends. METHODS: Data for confirmed and probable Lyme disease cases with episode dates from January 1, 2012, through December 31, 2017, were extracted from the integrated Public Health Information System (iPHIS). Data included public health unit (PHU) of residence, episode date, age and sex. Population data from Statistics Canada were used to calculate provincial and PHU-specific incidence rates per 100,000 population. The number of cases reported in 2017 by PHU of residence, month of occurrence, age and sex was compared to the 5-year averages for the period 2012-2016. RESULTS: There were 959 probable and confirmed cases of Lyme disease reported in Ontario in 2017. This was three times higher than the 5-year (2012-2016) average of 313. The provincial incidence rate for 2017 was 6.7 cases per 100,000 population, although this varied markedly by PHU. The highest incidence rates were found in Leeds-Grenville and Lanark District (128.8 cases per 100,000), Kingston-Frontenac, Lennox and Addington (87.2 cases per 100,000), Hastings and Prince Edward Counties (28.6 cases per 100,000), Ottawa (18.1 cases per 100,000) and Eastern Ontario (13.5 cases per 100,000). Cases occurred mostly from June through September, were most common among males, and those aged 5-14 and 50-69 years. CONCLUSION: In 2017, Lyme disease incidence showed a marked increase in Ontario, especially in the eastern part of the province. If current weather and climate trends continue, blacklegged ticks carrying tick-borne pathogens, such as those causing Lyme disease, will continue to spread into suitable habitat. Monitoring the extent of this geographic spread will inform future clinical and public health actions to detect and mitigate the impact of Lyme disease in Ontario.

Canadian recommendations for laboratory interpretation of multiple or extensive drug resistance in clinical isolates of Enterobacteriaceae, Acinetobacter species and Pseudomonas aeruginosa.

The goal of this document was to provide Canadian laboratories with a framework for consistent reporting and monitoring of multidrug resistant organisms (MDRO) and extensively drug resistant organisms (XDRO) for common gram-negative pathogens. This is the final edition of the interim recommendations, which were modified after one year of broad consultative review. This edition represents a consensus of peer-reviewed information and was co-authored by the Canadian Public Health Laboratory Network and the Canadian Association of Clinical Microbiology and Infectious Diseases. There are two main recommendations. The first recommendation provides standardized definitions for MDRO and XDRO for gram-negative organisms in clinical specimens. These definitions were limited to antibiotics that are commonly tested clinically and, to reduce ambiguity, resistance (rather than non-susceptibility) was used to calculate drug resistance status. The second recommendation identifies the use of standardized laboratory reporting of organisms identified as MDRO or XDRO. Through the broad consultation, which included public health and infection prevention and control colleagues, these definitions are ready to be applied for policy development. Both authoring organizations intend to review these recommendations regularly as antibiotic resistance testing evolves in Canada.

Laundering of hospital staff uniforms at home.

Few hospitals now launder staff uniforms. Staff are expected to use their own domestic machines, most of which run with 40 degrees C cycles. However, there is little information on the effectiveness of home laundering. This study demonstrates that domestic washing machines reduce viable counts of Staphylococcus aureus to below detectable levels from an inoculum of 10(8)-10(12) colony-forming units (>or=10(6)-fold reduction), even using low temperature (40 degrees C) programmes. Environmental organisms, predominantly Gram-negative flora, were introduced from the machine itself but were destroyed by tumble drying or ironing. Domestic laundering of uniforms is an acceptable alternative to hospital laundering if combined with tumble drying or ironing.

Fatal haemorrhage following a low-energy fracture of the pubic ramus.

We report a case of fatal haemorrhage following a low-energy fracture of the pubic ramus in an 85-year-old woman.

Spatial learning induces neurogenesis in the avian brain.

It is known from previous work that neurones are born continuously in the ventricular zone of the bird brain. In this study, we show that the amount of cell proliferation in the ventricular zone of the hippocampus (HP) and the hyperstriatum ventrale (HV) is influenced by behavioural experience. Two groups of birds (marsh tits) were compared: those allowed to store and retrieve food once every 3 days between days 35 and 56, and age-matched controls treated in an identical way, except that they were not allowed to store and retrieve food. After three trials of storing and retrieval, between days 35 and 41 posthatch, experienced birds showed a significantly higher rate of cell proliferation than did controls. The experienced birds also showed a significant increase in total cell and neuronal number by day 56 posthatch, after eight trials of storing and retrieval. There were no significant differences in the amount of programmed cell death in the hippocampus in this study. In a novel analysis of the data we demonstrate that the effect of experience between days 35 and 41 was to increase the daily rate of neurogenesis in the ventricular zone from 3.9 to 10%, and that this change could account for the increase in total hippocampal neuronal number by day 56 in the experienced birds. Thus, the observed increase in hippocampal volume and neuronal number as a result of food storing and retrieval, may be caused by an increase in neurogenesis in the first few trials of food storing experience.

Changes in the number and structure of dendritic spines 25 hours after passive avoidance training in the domestic chick, Gallus domesticus.

One-day-old chicks spontaneously peck at a shiny chrome bead. If the bead is coated with methylanthranilate, a bitter tasting substance (M-chicks), they peck once and avoid a similar bead subsequently. Control chicks peck, and continue pecking at a bead dipped in water (W-chicks). Twenty-five hours after this one-trial passive avoidance training the brains were fixed and Golgi-impregnated. A class of large, multipolar, projection neurons from the intermediate medial hyperstriatum ventrale (IMHV) of both hemispheres from M- and W-chicks were examined for changes in their spine density and spine shape. An estimate of the true spine number was obtained using the correction formula of Feldman and Peters. M-chicks showed highly significant increases (P less than 0.0001) in spine density of between 89-113% in the left hemisphere, and 37-69% in the right, compared with W-chicks. There was a significant hemispheric asymmetry in W-chicks: the right hemisphere had approximately 47% more spines per micron than the left, and this difference was abolished after training. Following passive avoidance training, significant increases in spine head diameter (by approximately 9%) and decreases in spine stem length (by approximately 17%), with no significant alterations in overall spine length, were observed in the left hemisphere. The mean dendrite lengths were not significantly changed after training, but an asymmetry of this measure in W-chicks (left greater than right) was present in dendrite orders 2 (P less than 0.01) and 3 (P less than 0.02). These results show that spine densities can increase rapidly (within 25 h) following a one-trial passive avoidance training task and that spine shape changes can be found on the same dendrites which also show changes in spine number. The data support the view that dendritic spines are involved in memory formation processes.

Training induced dendritic spine density changes are specifically related to memory formation processes in the chick, Gallus domesticus.

The density of dendritic spines on large, multipolar, projection neurons in the intermediate medial hyperstriatum ventrale (IMHV) of 1-day-old chicks was examined after training on a one-trial passive avoidance task. Chicks trained on the task were given a brief, subconvulsive transcranial electroshock 5 min after training, a procedure which rendered about half of them amnesic. The spine density was found to be significantly higher 24-26 h after training in the left IMHV in chicks that remembered the response compared to chicks rendered amnesic. These data, taken together with our earlier observations on spine density changes following training, argue strongly in favour of a specific role for dendritic spines in memory formation in the chick.

Nerve growth factor effects on the song control system of zebra finches.

The aim of this experiment was to test whether or not nerve growth factor (NGF) is involved in cholinergic processes in the avian brain, by injecting NGF into the higher vocal center (HVC) and examining its effects on adult male zebra finch song. Since NGF has been hypothesized to protect cells after injury, some birds received both NGF and ibotenic acid (IBO) lesions of HVC, while others received either NGF or IBO or neither (SHAM). Only the IBO-treated birds showed alterations in song. Although there was no evidence of cell preservation in the immunocytochemical and morphological analysis NGF appears to prevent the IBO induced impairment in song augmenting the activity of the remaining neurons and enhancing brain repair.

Automated analysis of electromyographic (EMG) recordings during botulinum injections.

PURPOSE: Botulinum toxin is injected into extraocular muscles using electromyographic (EMG) guidance to confirm needle location prior to injection. The purpose of this study was to develop and test an automated, objective method of storing and grading EMG signal quality obtained during botulinum injection. A reliable, nonsubjective estimate of signal quality will enhance future studies of the complications or effectiveness of botulinum toxin injections into extraocular muscle. METHODS: Injections were administered using a standard procedure. The EMG was digitized, recorded, and analyzed using discrete Fourier transform and power spectrum analysis. Audible signal quality was also graded subjectively by the surgeon. Patients were followed to determine the clinical response to the injection. RESULTS: Eighteen patients (24 injections) were studied. Each sample was collected and analyzed in less than one second. The EMG contained signals over a range of frequencies from 50 to 500 Hz, with an average peak near 90 Hz. Substantial variability of the signal was observed between patients. Contracting muscle had a higher total power and peak frequency in most, but not all, cases. Total signal power correlated moderately with subjective estimates of signal quality. Neither subjective nor computer-derived signal quality estimates correlated with the response to injection or complications. CONCLUSIONS: Computerized signal analysis can automatically characterize EMG signal power and frequency distribution. Although this technique has the potential to identify needle location at the time of botulinum injection accurately, signal variability limited the clinical and research utility of the present protocol.

Inhibition of Lck enhances glucocorticoid sensitivity and apoptosis in lymphoid cell lines and in chronic lymphocytic leukemia.

Glucocorticoids are used as part of front-line therapy to treat lymphoid malignancy because of their remarkable ability to induce apoptosis. Yet, in T cells, glucocorticoid-induced apoptosis is readily inhibited by lymphocyte activation and signaling. We have previously shown that the Src family kinase, Lck (lymphocyte cell-specific tyrosine kinase), which is predominantly expressed in T cells, interacts with IP3 receptors to facilitate calcium signaling. Here, we discovered that dexamethasone downregulates Lck, which, in turn, suppresses lymphocyte activation by inhibiting pro-survival calcium oscillations. Moreover, stable expression of shRNAs that selectively targeted Lck or treatment with the Src inhibitor dasatinib (BMS-354825) enhanced apoptosis induction by dexamethasone. To investigate the effect of Lck inhibition in a primary leukemia model, we employed chronic lymphocytic leukemia (CLL) cells that aberrantly expressed Lck and were relatively insensitive to dexamethasone. Lck expression was correlated with resistance to dexamethasone in CLL cells, and its inhibition by dasatinib or other inhibitors markedly enhanced glucocorticoid sensitivity. Collectively, these data indicate that Lck protects cells from glucocorticoid-induced apoptosis and its inhibition enhances sensitivity to dexamethasone. Small-molecule inhibitors of Lck, such as dasatinib, may function to reverse glucocorticoid resistance in some lymphoid malignancies.

Neural transplantation: problems and prospects for therapeutic application.

Successful demonstrations of behavioural recovery in a variety of lesion and mutant animal models have encouraged the application of neural transplantation to the alleviation of neurodegenerative disease. Apart from the continuing shortage of foetal tissue, the major problems to be resolved for successful application of neural transplantation to humans are: first, immune rejection of allograft tissue and its pathological consequences to both graft and host tissue; and second, the establishment of normal and extensive graft-host connectivity. Recent developments in transplant research are beginning successfully to apply a number of strategies to resolve these problems.