299 research outputs found
Sialylation of campylobacter jejuni lipo-oligosaccharides: impact on phagocytosis and cytokine production in mice
<p>Background:
Guillain-Barré syndrome (GBS) is a post-infectious polyradiculoneuropathy, frequently associated with antecedent Campylobacter jejuni (C. jejuni) infection. The presence of sialic acid on C. jejuni lipo-oligosaccharide (LOS) is considered a risk factor for development of GBS as it crucially determines the structural homology between LOS and gangliosides, explaining the induction of cross-reactive neurotoxic antibodies. Sialylated C. jejuni are recognised by TLR4 and sialoadhesin; however, the functional implications of these interactions in vivo are unknown.</p>
<p>Methodology/Principal Findings:
In this study we investigated the effects of bacterial sialylation on phagocytosis and cytokine secretion by mouse myeloid cells in vitro and in vivo. Using fluorescently labelled GM1a/GD1a ganglioside-mimicking C. jejuni strains and corresponding (Cst-II-mutant) control strains lacking sialic acid, we show that sialylated C. jejuni was more efficiently phagocytosed in vitro by BM-MΦ, but not by BM-DC. In addition, LOS sialylation increased the production of IL-10, IL-6 and IFN-β by both BM-MΦ and BM-DC. Subsequent in vivo experiments revealed that sialylation augmented the deposition of fluorescent bacteria in splenic DC, but not macrophages. In addition, sialylation significantly amplified the production of type I interferons, which was independent of pDC.</p>
<p>Conclusions/Significance:
These results identify novel immune stimulatory effects of C. jejuni sialylation, which may be important in inducing cross-reactive humoral responses that cause GBS</p>
Ocean impact on decadal Atlantic climate variability revealed by sea-level observations
Decadal variability is a notable feature of the Atlantic Ocean and the climate of the regions it influences. Prominently, this is manifested in the Atlantic Multidecadal Oscillation (AMO) in sea surface temperatures. Positive (negative) phases of the AMO coincide with warmer (colder) North Atlantic sea surface temperatures. The AMO is linked with decadal climate fluctuations, such as Indian and Sahel rainfall1, European summer precipitation2, Atlantic hurricanes3 and variations in global temperatures4. It is widely believed that ocean circulation drives the phase changes of the AMO by controlling ocean heat content5. However, there are no direct observations of ocean circulation of sufficient length to support this, leading to questions about whether the AMO is controlled from another source6. Here we provide observational evidence of the widely hypothesized link between ocean circulation and the AMO. We take a new approach, using sea level along the east coast of the United States to estimate ocean circulation on decadal timescales. We show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres—the intergyre region7. These circulation changes affect the decadal evolution of North Atlantic heat content and, consequently, the phases of the AMO. The Atlantic overturning circulation is declining8 and the AMO is moving to a negative phase. This may offer a brief respite from the persistent rise of global temperatures4, but in the coupled system we describe, there are compensating effects. In this case, the negative AMO is associated with a continued acceleration of sea-level rise along the northeast coast of the United States9, 10
Biophysical and electrochemical studies of protein-nucleic acid interactions
This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail
Ethnic and gender specific life expectancies of the Singapore population, 1965 to 2009 - Converging, or diverging?
10.1186/1471-2458-13-1012BMC Public Health131
The prevalence, patterns of usage and people's attitude towards complementary and alternative medicine (CAM) among the Indian community in Chatsworth, South Africa
BACKGROUND: The purpose of this study was to determine, among the Indian community of Chatsworth, South Africa, the prevalence and utilisation patterns of complementary and alternative medicine (CAM), attitudes associated with CAM use and communication patterns of CAM users with their primary care doctors. METHODS: Face-to-face structured interviews were conducted in Chatsworth, a suburb of Durban in which South Africans of Indian origin predominantly reside. Participants were 200 randomly selected adult English-speaking Indian residents. RESULTS: The prevalence of CAM usage for period 2000/2001 was 38.5% (95% confidence interval 31.7% to 45.6%). Spiritual healing and herbal/natural medicines, including vitamins were the most common types of CAM used, accounting for 42.8% and 48.1% respectively of overall CAM usage. People used CAM to treat conditions including diabetes mellitus, headaches, arthritis and joint pains, stress, skin disorders, backaches, hypertension and nasal disorders. Half of the CAM users used allopathic medicines concurrently. The cost of CAM utilization over this 1-year period, incurred by 80.5% of users for the duration of therapy for their most troublesome condition was below R500 (approximately US$50). Age, sex, marital status, religion, level of education and income were shown not to influence the use of CAM. Greater than half (51.9%) of CAM users did so either upon the advice of someone they knew, or after noticing a CAM advertisement in the local press. Seventy-nine percent of CAM users indicated that they had positive outcomes with their treatments. Fifty four percent of CAM users (excluding those using spiritual healing only) failed to inform their doctors that they used CAM. The main reason given by half of this group was that informing their doctors did not seem necessary. CONCLUSION: The prevalence of CAM in Chatsworth is similar to findings in other parts of the world. Although CAM was used to treat many different ailments, this practice could not be attributed to any particular demographic profile. The majority of CAM users were satisfied with the effects of CAM. Findings support a need for greater integration of allopathic medicine and CAM, as well as improved communication between patients and caregivers regarding CAM usage
Biochemical characterization of the carotenoid 1,2-hydratases (CrtC) from Rubrivivax gelatinosus and Thiocapsa roseopersicina
Two carotenoid 1,2-hydratase (CrtC) genes from the photosynthetic bacteria Rubrivivax gelatinosus and Thiocapsa roseopersicina were cloned and expressed in Escherichia coli in an active form and purified by affinity chromatography. The biochemical properties of the recombinant enzymes and their substrate specificities were studied. The purified CrtCs catalyze cofactor independently the conversion of lycopene to 1-HO- and 1,1′-(HO)2-lycopene. The optimal pH and temperature for hydratase activity was 8.0 and 30°C, respectively. The apparent Km and Vmax values obtained for the hydration of lycopene were 24 μM and 0.31 nmol h−1 mg−1 for RgCrtC and 9.5 μM and 0.15 nmol h−1 mg−1 for TrCrtC, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed two protein bands of 44 and 38 kDa for TrCrtC, which indicate protein processing. Both hydratases are also able to convert the unnatural substrate geranylgeraniol (C20 substrate), which functionally resembles the natural substrate lycopene
Targeting macrophage Histone deacetylase 3 stabilizes atherosclerotic lesions
Macrophages are key immune cells found in atherosclerotic plaques and critically shape atherosclerotic disease development. Targeting the functional repertoire of macrophages may hold novel approaches for future atherosclerosis management. Here, we describe a previously unrecognized role of the epigenomic enzyme Histone deacetylase 3 (Hdac3) in regulating the atherosclerotic phenotype of macrophages. Using conditional knockout mice, we found that myeloid Hdac3 deficiency promotes collagen deposition in atherosclerotic lesions and thus induces a stable plaque phenotype. Also, macrophages presented a switch to anti-inflammatory wound healing characteristics and showed improved lipid handling. The pro-fibrotic phenotype was directly linked to epigenetic regulation of the Tgfb1 locus upon Hdac3 deletion, driving smooth muscle cells to increased collagen production. Moreover, in humans, HDAC3 was the sole Hdac upregulated in ruptured atherosclerotic lesions, Hdac3 associated with inflammatory macrophages, and HDAC3 expression inversely correlated with pro-fibrotic TGFB1 expression. Collectively, we show that targeting the macrophage epigenome can improve atherosclerosis outcome and we identify Hdac3 as a potential novel therapeutic target in cardiovascular disease
Uncovering the nutritional landscape of food
Recent progresses in data-driven analysis methods, including network-based
approaches, are revolutionizing many classical disciplines. These techniques
can also be applied to food and nutrition, which must be studied to design
healthy diets. Using nutritional information from over 1,000 raw foods, we
systematically evaluated the nutrient composition of each food in regards to
satisfying daily nutritional requirements. The nutrient balance of a food was
quantified herein as nutritional fitness, using the food's frequency of
occurrence in nutritionally adequate food combinations. Nutritional fitness
offers prioritization of recommendable foods within a global network of foods,
in which foods are connected based on the similarities of their nutrient
compositions. We identified a number of key nutrients, such as choline and
alpha-linolenic acid, whose levels in foods can critically affect the foods'
nutritional fitness. Analogously, pairs of nutrients can have the same effect.
In fact, two nutrients can impact the nutritional fitness synergistically,
although the individual nutrients alone may not. This result, involving the
tendency among nutrients to show correlations in their abundances across foods,
implies a hidden layer of complexity when exploring for foods whose balance of
nutrients within pairs holistically helps meet nutritional requirements.
Interestingly, foods with high nutritional fitness successfully maintain this
nutrient balance. This effect expands our scope to a diverse repertoire of
nutrient-nutrient correlations, integrated under a common network framework
that yields unexpected yet coherent associations between nutrients. Our
nutrient-profiling approach combined with a network-based analysis provides a
more unbiased, global view of the relationships between foods and nutrients,
and can be extended towards nutritional policies, food marketing, and
personalized nutrition.Comment: Supplementary material is available at the journal websit
Detection of sexually transmitted infection and human papillomavirus in negative cytology by multiplex-PCR
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to determine the prevalence of human papillomavirus (HPV) and 15 species that cause sexually transmitted infections (STIs) in negative cytology. In addition, we compared the diagnostic performance of multiplex polymerase chain reaction (PCR) with widely available techniques used to detect HPV.</p> <p>Methods</p> <p>We recruited 235 women of reproductive age who had negative cytology findings in a liquid-based cervical smear. STIs were identified by multiplex PCR, and HPV genotypes by multiplex PCR, hybrid capture 2, and DNA microaray; discordant results were analyzed by direct sequencing.</p> <p>Results</p> <p>Approximately 96.6% of patients with negative cytology results were positive for pathogens that cause STIs. The pathogens most frequently detected were <it>Gardnerella vaginalis, Ureaplasma urealyticum</it>. The incidence of HPV in negative cytology was 23.3%. Low-risk HPV infection was significantly correlated with <it>Chalmaydia trachomatis</it>, and high-risk HPV infection was significantly correlated with <it>Group β streptococcus</it>. The analytical sensitivities of the multiplex PCR and DNA microarray were higher than 80%, and the analytical specificity was nearly 100% for all tests.</p> <p>Conclusions</p> <p>Multiplex PCR yielded results that most of patients with negative cytology were positive for pathogens that cause STIs, and were more similar to that of DNA microarray, than that of hybrid capture 2 in terms of analytical sensitivity and prediction value of HPV infection.</p
Five-year change of clinical and complications profile of diabetic patients under primary care: a population-based longitudinal study on 127,977 diabetic patients
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