142 research outputs found
Conventional and molecular epidemiology of Tuberculosis in Manitoba
BACKGROUND: To describe the demographic and geographic distribution of tuberculosis (TB) in Manitoba, thus determining risk factors associated with clustering and higher incidence rates in distinct subpopulations. METHODS: Data from the Manitoba TB Registry was compiled to generate a database on 855 patients with tuberculosis and their contacts from 1992–1999. Recovered isolates of M. tuberculosis were typed by IS6110 restriction fragment length polymorphisms. Bivariate and multivariate logistic regression models were used to identify risk factors involved in clustering. RESULTS: A trend to clustering was observed among the Canadian-born treaty Aboriginal subgroup in contrast to the foreign-born. The dominant type, designated fingerprint type 1, accounts for 25.8% of total cases and 75.3% of treaty Aboriginal cases. Among type 1 patients residing in urban areas, 98.9% lived in Winnipeg. In rural areas, 92.8% lived on Aboriginal reserves. Statistical models revealed that significant risk factors for acquiring clustered tuberculosis are gender, age, ethnic origin and residence. Those at increased risk are: males (p < 0.05); those under age 65 (p < 0.01 for each age subgroup); treaty Aboriginals (p < 0.001), and those living on reserve land (p < 0.001). CONCLUSION: Molecular typing of isolates in conjunction with contact tracing data supports the notion of the largest ongoing transmission of a single strain of TB within the treaty-status population of Canada recorded to date. This data demonstrates the necessity of continued surveillance of countries with low prevalence of the disease in order to determine and target high-risk populations for concentrated prevention and control measures
Integrated Millimeter-Wave Antennas for On-Chip Communication
This paper introduces the design and analysis of circularly polarized (CP) and dual-polarized on-chip microstrip antennas for wireless communication at 60 GHz. The CP on-chip antenna consists of a circular aluminum patch with two overlapped circular slots fed by the transmission line. The radiation characteristics of the CP have been analyzed using the finite integration technique and finite element method based electromagnetic solvers. The CP antenna introduces left-hand circular polarization and employs as on-chip transmitter. A design of dual-polarized on-chip microstrip antenna at 60 GHz is investigated and is employed as on-chip receiver. The dual ports of the dual polarized antenna are designed with high isolation between them in order to be used as a two on-chip receivers. The radiation characteristics of the dual-port antenna have been calculated. The effect of the separation distance between the CP-antenna and the dual-polarized antenna on the same chip has been investigated. The performance parameters like the reflection coefficient, transmission coefficient, and the transmission gain of the two antennas at different separation distances have been introduced
Different Designs of Dual-Focus Perforated Transmitarray Antenna in Near/Far-Field Region
Designs of the single-focus and multi-focused transmitarray antennas for the near-field (NF) or/and far-field (FF) applications have been introduced. Perforated dielectric single sheet is used for transmitarray design for simple configuration. Single-focus transmitarray for the far-field and the near-field are obtained. The radiation characteristics of 13×13 unit-cells transmitarray in the near-field and the far-field region have been investigated. A single structure multi-focus transmitarray is designed using the chess-board arrangement of the unit-cells elements. Multi-focus transmitarray for FF/FF, FF/NF, and NF/NF have been designed and investigated. The phase distribution and the corresponding holes radii for the first quadrant of the multi-focus transmitarray are presented. The radiation characteristics of different array configuration have been investigated and analyzed using full-wave simulator CST Microwave Studio
Identification of a predominant isolate of Mycobacterium tuberculosis using molecular and clinical epidemiology tools and in vitro cytokine responses
BACKGROUND: Tuberculosis (TB) surveillance programs in Canada have established that TB in Canada is becoming a disease of geographically and demographically distinct groups. In 1995, treaty status aboriginals from the province of Manitoba accounted for 46% of the disease burden of this sub-group in Canada. The TB incidence rates are dramatically high in certain reserves of Manitoba and are equivalent to rates in African countries. The objective of our study was to identify prevalent isolates of Mycobacterium tuberculosis in the patient population of Manitoba using molecular epidemiology tools, studying the patient demographics associated with the prevalent strain and studying the in vitro cytokine profiles post-infection with the predominant strain. METHODS: Molecular typing was performed on all isolates available between 1992 to1997. A clinical database was generated using patient information from Manitoba. THP-1 cells were infected using strains of M. tuberculosis and cytokine profiles were determined using immunoassays for cytokines IL-1β, IL-10, IL-12, IFN-γ and TNF-α. RESULTS: In Manitoba, 24% of the disease burden is due to a particular M. tuberculosis strain (Type1). The strain is common in patients of aboriginal decent and is responsible for at least 87% of these cases. Cytokine assays indicate that the Type1 strain induces comparatively lower titers of IL-1β, IFN-γ and TNF-α in infected THP-1 cells as compared to H37Ra and H37Rv strains. CONCLUSION: In Manitoba, Type1 strain is predominant in TB patients. The majority of the cases infected with this particular strain are newly active with a high incidence of respiratory disease, positive chest radiographs and pulmonary cavities. In vitro secretion of IL-1β, IFN-γ and TNF-α is suppressed in Type1 infected culture samples when compared to H37Ra and H37Rv infected cells
Apple polyphenol extract improves insulin sensitivity in vitro and in vivo in animal models of insulin resistance
Background:
Apple polyphenols could represent a novel nutritional approach in the management and control of blood glucose, especially in type 2 diabetics. The aim of this study was to test the therapeutic potential of an apple polyphenol extract (APE) in an insulin-resistant rat model and to determine the molecular basis of insulin sensitivity action in skeletal muscle cells.Methods:
Acute effect of APE on the postprandial hyperglycemic response was assayed in 15 week old obese Zucker rats (OZR), by using a meal tolerance test (MTT). The ability of APE to improve whole peripheral insulin sensitivity was also assayed in a chronic study by using the euglycemic-hyperinsulinemic clamp technique. To elucidate the molecular mechanisms, rat L6 myotubes were used. Glucose uptake was measured by using 2-[3H]-Deoxy-Glucose (2-DG) and specific inhibitors, as well as phosphorylation status of key kinases, were used to determine the implicated signaling pathway.Results:
In vivo study showed that nutritional intervention with APE induced an increase of insulin sensitivity with an increase of glucose infusion rate (GIR) of 45 %. Additionally, in vitro results showed a synergistic effect between APE and insulin as well as increased glucose uptake through GLUT4 translocation in muscle cells. This translocation was mediated by phosphatydil inositol 3-kinase (PI3K) and peroxisome proliferator-activated receptor-gamma (PPARγ) signaling pathways.Conclusions:
As a whole, this study describes the mechanisms involved in the insulin sensitizing effect of APE, which could be considered a promising ingredient for inclusion in nutritional products focused on the management of chronic diseases such as diabetes.This research was supported by funds from Abbott Laboratories S.A
Structure-based in silico identification of ubiquitin-binding domains provides insights into the ALIX-V:ubiquitin complex and retrovirus budding
Sh3pxd2b Mice Are a Model for Craniofacial Dysmorphology and Otitis Media
Craniofacial defects that occur through gene mutation during development increase vulnerability to eustachian tube dysfunction. These defects can lead to an increased incidence of otitis media. We examined the effects of a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) on the progression of otitis media and hearing impairment at various developmental stages. We found that all mice that had the Sh3pxd2bnee mutation went on to develop craniofacial dysmorphologies and subsequently otitis media, by as early as 11 days of age. We found noteworthy changes in cilia and goblet cells of the middle ear mucosa in Sh3pxd2bnee mutant mice using scanning electronic microscopy. By measuring craniofacial dimensions, we determined for the first time in an animal model that this mouse has altered eustachian tube morphology consistent with a more horizontal position of the eustachian tube. All mutants were found to have hearing impairment. Expression of TNF-α and TLR2, which correlates with inflammation in otitis media, was up-regulated in the ears of mutant mice when examined by immunohistochemistry and semi-quantitative RT-PCR. The mouse model with a mutation in the Sh3pxd2b gene (Sh3pxd2bnee) mirrors craniofacial dysmorphology and otitis media in humans
Traditional knowledge of wild edible plants used in Palestine (Northern West Bank): A comparative study
<p>Abstract</p> <p>Background</p> <p>A comparative food ethnobotanical study was carried out in fifteen local communities distributed in five districts in the Palestinian Authority, PA (northern West Bank), six of which were located in Nablus, two in Jenin, two in Salfit, three in Qalqilia, and two in Tulkarm. These are among the areas in the PA whose rural inhabitants primarily subsisted on agriculture and therefore still preserve the traditional knowledge on wild edible plants.</p> <p>Methods</p> <p>Data on the use of wild edible plants were collected for one-year period, through informed consent semi-structured interviews with 190 local informants. A semi-quantitative approach was used to document use diversity, and relative importance of each species.</p> <p>Results and discussion</p> <p>The study recorded 100 wild edible plant species, seventy six of which were mentioned by three informants and above and were distributed across 70 genera and 26 families. The most significant species include <it>Majorana syriaca, Foeniculum vulgare, Malvasylvestris</it>, <it>Salvia fruticosa, Cyclamen persicum, Micromeria fruticosa, Arum palaestinum, Trigonella foenum-graecum</it>, <it>Gundelia tournefortii</it>, and <it>Matricaria aurea</it>. All the ten species with the highest mean cultural importance values (mCI), were cited in all five areas. Moreover, most were important in every region. A common cultural background may explain these similarities. One taxon (<it>Majoranasyriaca</it>) in particular was found to be among the most quoted species in almost all areas surveyed. CI values, as a measure of traditional botanical knowledge, for edible species in relatively remote and isolated areas (Qalqilia, and Salfit) were generally higher than for the same species in other areas. This can be attributed to the fact that local knowledge of wild edible plants and plant gathering are more spread in remote or isolated areas.</p> <p>Conclusion</p> <p>Gathering, processing and consuming wild edible plants are still practiced in all the studied Palestinian areas. About 26 % (26/100) of the recorded wild botanicals including the most quoted and with highest mCI values, are currently gathered and utilized in all the areas, demonstrating that there are ethnobotanical contact points among the various Palestinian regions. The habit of using wild edible plants is still alive in the PA, but is disappearing. Therefore, the recording, preserving, and infusing of this knowledge to future generations is pressing and fundamental.</p
Chlamydia trachomatis Infection and Anti-Hsp60 Immunity: The Two Sides of the Coin
Chlamydia trachomatis (CT) infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60) and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human) may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician
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