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1.
Nutr Res ; 107: 75-85, 2022 11.
Article in English | MEDLINE | ID: mdl-36206635

ABSTRACT

Dietary intake may interact with gene variants and modulate inflammatory status. This study aimed to investigate the combined effect of fat mass and obesity-associated rs9930501, rs9930506, and rs9932754 and beta-2 adrenergic receptor rs1042713 on C-reactive protein (CRP) concentrations using polygenic risk scores (PRS), and modulatory effect of dietary nutrients on these associations. We hypothesized that higher protein intake is associated with lower inflammatory status in individuals genetically predisposed to obesity. PRS was computed as the weighted sum of the risk alleles possessed and stratified into first (0-0.64), second (0.65-3.59), and third (3.60-8.18) tertiles. A total of 128 overweight and obese Malaysian adults were dichotomized into groups of low and elevated inflammatory status (CRP concentrations ≤3 and >3 mg/L, respectively). One-half of the study participants (51%) were found to have elevated inflammatory status. Second- and third-tertile PRS were significantly associated with increased odds of elevated inflammatory status, 7.56 (95% confidence interval [CI], 1.98-28.80; adjusted P = .003) and 3.87 (95% CI, 1.10-13.60; adjusted P = .035), respectively. Individuals in the third-tertile PRS had significantly lower CRP concentrations (4.61 ± 1.3 mg/L vs 9.60 ± 2.6 mg/L, P = .019) when consuming ≥14% energy from protein (with an average of 18.0% ± 2.4%, 43.0% ± 7.7%, and 39.0% ± 8.0% energy from protein, carbohydrate, and fat per day). In conclusion, third-tertile PRS was significantly associated with increased odds of elevated CRP; higher protein intake may alleviate inflammatory status and reduce CRP concentrations systemically in those individuals.


Subject(s)
C-Reactive Protein , Dietary Proteins , Obesity , Overweight , Adult , Humans , C-Reactive Protein/metabolism , Obesity/genetics , Overweight/genetics , Risk Factors , Malaysia
2.
Curr Gerontol Geriatr Res ; 2021: 6634474, 2021.
Article in English | MEDLINE | ID: mdl-33790963

ABSTRACT

Osteosarcopenic obesity (OSO) describes the concurrent presence of obesity, low bone mass, and low muscle mass in an individual. Currently, no established criteria exist to diagnose OSO. We hypothesized that obese individuals require different cut-points from standard cut-points to define low bone mass and low muscle mass due to their higher weight load. In this study, we determined cutoff values for the screening of osteosarcopenia (OS) in obese postmenopausal Malaysian women based on the measurements of quantitative ultrasound (QUS), bioelectrical impedance analysis (BIA), and functional performance test. Then, we compared the cutoff values derived by 3 different statistical modeling methods, (1) receiver operating characteristic (ROC) curve, (2) lowest quintile of the study population, and (3) 2 standard deviations (SD) below the mean value of a young reference group, and discussed the most suitable method to screen for the presence of OS in obese population. One hundred and forty-one (n = 141) postmenopausal Malaysian women participated in the study. Bone density was assessed using calcaneal quantitative ultrasound. Body composition was assessed using bioelectrical impedance analyzer. Handgrip strength was assessed using a handgrip dynamometer, and physical performance was assessed using a modified Short Physical Performance Battery test. ROC curve was determined to be the most suitable statistical modeling method to derive the cutoffs for the presence of OS in obese population. From the ROC curve method, the final model to estimate the probability of OS in obese postmenopausal women is comprised of five variables: handgrip strength (HGS, with area under the curve (AUC) = 0.698 and threshold ≤ 16.5 kg), skeletal muscle mass index (SMMI, AUC = 0.966 and threshold ≤ 8.2 kg/m2), fat-free mass index (FFMI, AUC = 0.946 and threshold ≤ 15.2 kg/m2), broadband ultrasonic attenuation (BUA, AUC = 0.987 and threshold ≤ 52.85 dB/MHz), and speed of sound (SOS, AUC = 0.991 and threshold ≤ 1492.15 m/s). Portable equipment may be used to screen for OS in obese women. Early identification of OS can help lower the risk of advanced functional impairment that can lead to physical disability in obese postmenopausal women.

3.
Article in English | WPRIM (Western Pacific) | ID: wpr-907095

ABSTRACT

@#Introduction: The optimal level of total 25(OH)D in Malaysian postmenopausal women that is necessary to ameliorate the combined effects of decreased bone mineral and muscle mass, and increase in adiposity, as seen in osteosarcopenic obesity, is unknown. Given that these are common pathologies existing in bone, muscle and excess fat-related disorders, this study investigated the association between body composition, functional capacity and total 25(OH)D levels. Methods: This was a cross-sectional study involving 117 postmenopausal Malaysian women aged 50-88 years. Total 25(OH)D was analysed by chemiluminescent microparticle immunoassay CMIA on Siemens® platforms. Bone mineral was measured by broadband ultrasound attenuation. Functional performance was assessed using modified components of short physical performance battery test. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS Version 25.0). Results: Overall, 47% women were vitamin D deficient; 3% had none, 22% had one, 65% had two, and 10% had all three adverse body composition indicators (osteosarcopenic obesity). Individuals without any adverse body composition indicator had higher total 25(OH) D (74.7±7.0nmol/L, p=0.004) compared to all the other groups [1 (53.0±3.8nmol/L); 2 (48.7±1.9nmol/L) and 3 (58.3±5.4nmol/L)]. The single inflection point (ROC curve) for total 25(OH)D in predicting osteosarcopenic obesity was 58.9nmol/L. Conclusion: Higher vitamin D levels were associated with lower body fat, enhanced bone quality, and improved functional capacity. Maintaining vitamin D levels above >58.9nmol/L may protect Malaysian postmenopausal women against the combined pathologies of bone, muscle and excess fat.

4.
BMC Nutr ; 6: 32, 2020.
Article in English | MEDLINE | ID: mdl-32612845

ABSTRACT

BACKGROUND: The main purpose of this paper is to understand the multidimensional phenomenon of the nutrition transition in Malaysia, from 1980 to 2014, to inform future policies for a healthier nation. METHODS: Food and health data were obtained through Food Balance Sheets, Malaysian Adult Nutrition Survey (MANS) and National Health and Morbidity Surveys (NHMS) for year-to-year review. Interaction between changes in food supplies and dietary trends and the progression of diet-related diseases and risk factors in tandem with demographic and socioeconomic transitions were observed using quasi-historical approach. RESULTS: The period-under-review has seen Malaysia becoming more affluent, urbanised and modernised. Energy supply for Malaysian population remained consistently in excess of average calorie needs by a minimum of 30%. There were significant signs of shifting food trends, particularly in the supply of wheat (+ 56.5%), rice (- 23.7%), sugar and sweeteners (+ 23.9%), meat (+ 49.3%), fish and seafood (+ 38.7%), and eggs (+ 55.7%). The plant/animal protein ratio has decreased over time. Prevalence of NCD and associated risk factors has increased rapidly, some as high as 170%, despite various policy efforts to reduce them. CONCLUSION: The study highlights the importance of policymakers taking a relook into its policies and strategies, and formulate sustainable, comprehensive and multifaceted actions together with all relevant stakeholders to ensure a conducive, healthy and nutritious food systems and environment for its population.

5.
Lifestyle Genom ; 13(2): 84-98, 2020.
Article in English | MEDLINE | ID: mdl-32101872

ABSTRACT

BACKGROUND: Computing polygenic risk scores (PRS) to predict the degree of risk for obesity may contribute to weight management programs strategically. OBJECTIVES: To investigate the combined effect of FTO rs9930501, rs9930506, and rs9932754 and ADRB2 rs1042713 and rs1042714 using PRS on (1) the odds of obesity and (2) post-intervention differences in dietary, anthropometric, and cardiometabolic parameters in response to high-protein calorie-restricted, high-vitamin E, high-fiber (Hipcref) diet intervention in Malaysian adults. METHODS: Both a cross-sectional study (n = 178) and a randomized controlled trial (RCT) (n = 128) were conducted to test the aforementioned objectives. PRS was computed as the weighted sum of the risk alleles possessed by each individual participant. Participants were stratified into first (PRS 0-0.64), second (PRS 0.65-3.59), and third (PRS 3.60-8.18) tertiles. RESULTS: The third tertile of PRS was associated with significantly higher odds of obesity: 2.29 (95% CI = 1.11-4.72, adjusted p = 0.025) compared to the first tertile. Indians (3.9 ± 0.3) had significantly higher PRS compared to Chinese (2.1 ± 0.4) (p = 0.010). In the RCT, a greater reduction in high-sensitivity C-reactive protein (hsCRP) levels was found in second and third tertiles after Hipcref diet intervention compared to the control diet (p interaction = 0.048). CONCLUSION: Higher PRS was significantly associated with increased odds of obesity. Individuals with higher PRS had a significantly greater reduction in hsCRP levels after Hipcref diet compared to the control diet.


Subject(s)
Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics , Diet , Genetic Predisposition to Disease , Genetic Variation , Obesity/genetics , Polymorphism, Single Nucleotide , Receptors, Adrenergic, beta-2/genetics , Adolescent , Adult , Aged , Alleles , Anthropometry , Body Weight , C-Reactive Protein/metabolism , Cross-Sectional Studies , Diet, Reducing , Dietary Fiber , Energy Intake , Ethnicity , Female , Gene-Environment Interaction , Genotype , Humans , Malaysia/epidemiology , Male , Middle Aged , Odds Ratio , Overweight , Phenotype , Risk , Vitamin E/metabolism , Young Adult
6.
Metabolites ; 11(1)2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33396337

ABSTRACT

The concurrent presence of low bone density (osteopenia/osteoporosis) and low muscle mass (sarcopenia) in older adults has led to the recognition of "osteosarcopenia" (OS) as a singular entity. Vitamin D may play important role in the manifestation of OS, in terms of intake, absorption, and bioavailability. Evidence suggests that bioavailable 25(OH)D may be a better indicator of Vitamin D compared to total 25(OH)D due to its weak bind to albumin, increasing its 'availability'. The aim of this study was to assess total and bioavailable 25(OH)D levels in postmenopausal women and to determine their associations to bone density and muscle mass. We assessed body composition, bone density, and 25(OH)D indices of multiethnic, postmenopausal Malaysian women. A significant and negative correlation was found between body fat % and each index of 25(OH)D. Both bioavailable and total 25(OH)D were positively correlated with serum calcium and negatively correlated with iPTH. VDBP level was significantly correlated with bioavailable 25(OH)D level, but not with the total 25(OH)D level. Stepwise regression analysis revealed that bioavailable, but not total, 25(OH)D was significantly correlated to bone density and muscle mass, (where stronger correlation was found with bone density), suggesting its superiority. Nevertheless, the low effect size warrants further studies.

7.
J Nutr Metab ; 2019: 8718795, 2019.
Article in English | MEDLINE | ID: mdl-31007954

ABSTRACT

Gene-diet interaction studies have reported that individual variations in phenotypic traits may be due to variations in individual diet. Our study aimed to evaluate (i) the association of ADRB2 rs1042713 with obesity and obesity-related metabolic parameters and (ii) the effect of dietary nutrients on these associations in Malaysian adults. ADRB2 genotyping, dietary, physical activity, anthropometric, and biochemical data were collected from 79 obese and 99 nonobese individuals. Logistic regression revealed no association between ADRB2 rs1042713 and obesity (p=0.725). However, the carriers of G allele (AG + GG genotypes) of rs1042713 were associated with increased odds of insulin resistance, 2.83 (CI = 1.04-7.70, adjusted p=0.042), in the dominant model, even after adjusting for potential confounders. Obese individuals carrying the G allele were associated with higher total cholesterol (p=0.011), LDL cholesterol levels (p=0.008), and total cholesterol/HDL cholesterol ratio (p=0.048), compared to the noncarriers (AA), even after adjusting for potential confounders. Irrespective of obesity, the carriers of GG genotype had significantly lower fasting glucose levels with low saturated fatty acid intake (<7.3% of TE/day) (4.92 ± 0.1 mmol/L vs 5.80 ± 0.3 mmol/L, p=0.011) and high intake of polyunsaturated fatty acid:saturated fatty acid ratio (≥0.8/day) (4.83 ± 0.1 mmol/L vs 5.93 ± 0.4 mmol/L, p=0.006). Moreover, the carriers of GG genotype with high polyunsaturated fatty acid intake (≥6% of TE/day) had significantly lower HOMA-IR (1.5 ± 0.3 vs 3.0 ± 0.7, p=0.026) and fasting insulin levels (6.8 ± 1.6 µU/mL vs 11.4 ± 2.1 µU/mL, p=0.036). These effects were not found in the noncarriers (AA). In conclusion, G allele carriers of ADRB2 rs1042713 were associated with increased odds of insulin resistance. Obese individuals carrying G allele were compromised with higher blood lipid levels. Although it is premature to report gene-diet interaction on the regulation of glucose and insulin levels in Malaysians, we suggest that higher quantity of PUFA-rich food sources in regular diet may benefit overweight and obese Malaysian adults metabolically. Large-scale studies are required to replicate and confirm the current findings in the Malaysian population.

8.
Microbes Infect ; 21(8-9): 368-376, 2019.
Article in English | MEDLINE | ID: mdl-30853357

ABSTRACT

Multiple diarrheagenic enteric bacterial infections cause global morbidity and mortality. A combination vaccine is needed to combat different diarrhea-causing organisms. In our present work, we formulated a combination of antigens from three different diarrheagenic Escherichia coli strains and three different Vibrio cholerae strains. We demonstrated that our newly formulated combination immunogen was able to raise species-specific immunogenicity. This formulation also gave protection against different diarrheagenic E. coli strains in the removable intestinal tie-adult rabbit diarrhea model. However, protective efficacy was not found against the V. cholerae El Tor Ogawa Haitian variant, but challenged with V. cholerae El Tor Inaba or O139 showed protection in rabbits. This is the first report of a single formulated nonliving heat-killed combination immunogen from different diarrheagenic E. coli and V. cholerae that could bestow protection against different bacteria in an animal model.


Subject(s)
Cholera Vaccines/immunology , Cholera/prevention & control , Diarrhea/prevention & control , Escherichia coli Infections/prevention & control , Escherichia coli Vaccines/immunology , Escherichia coli/immunology , Vibrio cholerae/immunology , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Antigens, Bacterial/immunology , Cholera Vaccines/administration & dosage , Cross Protection/immunology , Diarrhea/microbiology , Disease Models, Animal , Escherichia coli/genetics , Escherichia coli Vaccines/administration & dosage , Immunization , Immunoglobulins/blood , Rabbits , Vaccines, Combined/immunology , Vaccines, Inactivated/immunology , Vibrio cholerae/genetics
9.
Br J Nutr ; 121(9): 1002-1017, 2019 05.
Article in English | MEDLINE | ID: mdl-30761964

ABSTRACT

The aim of this study was to investigate the effectiveness of the Hipcref (high-protein, energy-restricted, high-vitamin E and high-fibre) diet in Malaysian adults on body composition and metabolic parameters after an intervention period of 6 months. Overweight/obese Malaysian adults (n 128; BMI≥23 kg/m2) were randomised to the Hipcref (n 65) or control diet (n 63). The intervention group received Hipcref diet charts based on their personal preferences. The control group followed a generalised dietary advice based on Malaysian Dietary Guidelines, 2010. All participants were responsible for preparing their own meals. There was a significant treatment group×time effect on anthropometric parameters (P<0·05) on an intention-to-treat basis. Pairwise comparisons revealed that Hipcref diet participants had significant reduction in weight, BMI, waist circumference, fat mass and percentage body fat at months 3 and 6 compared with baseline (P<0·001). The control group had significant increase in weight and BMI at months 3 and 6 compared with baseline (P<0·05). The Hipcref diet group had higher reduction in fasting insulin, insulin resistance and C-reactive protein levels compared with the control group at month 6 (P<0·05). Post-intervention, compared with the control group, the Hipcref diet group was found to consume significantly higher percentage energy from protein, and PUFA, higher energy-adjusted vitamin E (mg) and fibre (g), and lower total energy, lower percentage energy from fat and carbohydrate (P<0·05). The success of the Hipcref diet on overweight/obese Malaysian adults may be due to the combined effect of the nutrient composition of the Hipcref diet.


Subject(s)
Anthropometry , Caloric Restriction/methods , Diet, High-Protein/methods , Obesity/diet therapy , Overweight/diet therapy , Adult , Body Composition , Body Weight , Dietary Proteins/analysis , Female , Humans , Insulin Resistance , Intention to Treat Analysis , Malaysia , Male , Middle Aged , Obesity/physiopathology , Overweight/physiopathology , Treatment Outcome , Waist Circumference , Weight Loss
10.
PeerJ ; 6: e5626, 2018.
Article in English | MEDLINE | ID: mdl-30294510

ABSTRACT

The variation between the actual and perceived lightness of a stimulus has strong dependency on its background, a phenomena commonly known as lightness induction in the literature of visual neuroscience and psychology. For instance, a gray patch may perceptually appear to be darker in a background while it looks brighter when the background is reversed. In the literature it is further reported that such variation can take place in two possible ways. In case of stimulus like the Simultaneous Brightness Contrast (SBC), the apparent lightness changes in the direction opposite to that of the background lightness, a phenomenon often referred to as lightness contrast, while in the others like neon colour spreading or checkerboard illusion it occurs opposite to that, and known as lightness assimilation. The White's illusion is a typical one which according to many, does not completely conform to any of these two processes. This paper presents the result of quantification of the perceptual strength of the White's illusion as a function of the width of the background square grating as well as the length of the gray patch. A linear filter model is further proposed to simulate the possible neurophysiological phenomena responsible for this particular visual experience. The model assumes that for the White's illusion, where the edges are strong and quite a few, i.e., the spectrum is rich in high frequency components, the inhibitory surround in the classical Difference-of-Gaussians (DoG) filter gets suppressed, and the filter essentially reduces to an adaptive scale Gaussian kernel that brings about lightness assimilation. The linear filter model with a Gaussian kernel is used to simulate the White's illusion phenomena with wide variation of spatial frequency of the background grating as well as the length of the gray patch. The appropriateness of the model is presented through simulation results, which are highly tuned to the present as well as earlier psychometric results.

11.
Public Health Genomics ; 21(5-6): 169-185, 2018.
Article in English | MEDLINE | ID: mdl-31117103

ABSTRACT

BACKGROUND/AIMS: Excess weight gain is a result of the interaction between diet, environment, and genes. Evidence suggests that responses to lifestyle interventions to manage weight are partially modified by genetic factors. This review is aimed at summarizing the current evidence from studies done on gene variants - single nucleotide polymorphisms (SNPs) - and intervention outcomes on weight loss and obesity-related traits. METHODS: Intervention studies published in English between 2000 and August 2018 were retrieved from PubMed, Google Scholar, and Web of Science using various keywords. RESULTS: This article is a review of 36 studies conducted in 13 different countries which included a total of 15,931 participants between 19 and 70 years of age. The effect of 26 genes and 64 SNPs on the reduction of body weight and metabolic risk factors in response to diet, exercise, and lifestyle interventions was reviewed. CONCLUSION: Gene-lifestyle interaction studies on the same candidate gene in different populations have reported information which is challenging to interpret. Thus, it is difficult to arrive at a particular model for a strategy on weight management at this point in time. Most of the intervention studies focus on the effect of variants of a single candidate gene on weight loss. Further evidence from large-scale studies is necessary to assess the effect of multiple candidate genes to compute a gene score that could be used in a model intervention programme. Our review suggests that a healthy lifestyle with a balanced diet and regular physical activity will benefit individuals who carry the risk alleles of the obesity-related candidate genes. This message should be the mainstay of the recommendations and guidelines published by nutrition societies across the world.

12.
PLoS Negl Trop Dis ; 11(7): e0005728, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28727722

ABSTRACT

Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.


Subject(s)
Cross Protection , Dysentery, Bacillary/prevention & control , Gene Deletion , Host Factor 1 Protein/deficiency , Shigella Vaccines/immunology , Shigella/genetics , Shigella/immunology , Animals , Disease Models, Animal , Dysentery, Bacillary/immunology , Dysentery, Bacillary/pathology , Guinea Pigs , Male , Microbial Viability , Serogroup , Shigella Vaccines/administration & dosage , Shigella Vaccines/genetics , Survival Analysis , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/genetics , Vaccines, Attenuated/immunology , Virulence
13.
Vaccine ; 35(28): 3534-3547, 2017 06 16.
Article in English | MEDLINE | ID: mdl-28545924

ABSTRACT

Bacterial outer membrane vesicles have been extensively investigated and considered as a next generation vaccine. Recently, we have demonstrated that the cholera pentavalent outer membrane vesicles (CPMVs) immunogen induced adaptive immunity and had a strong protective efficacy against the circulating V. cholerae strains in a mouse model. In this present study, we are mainly focusing on reducing outer membrane vesicle (OMV) -mediated toxicity without altering its antigenic property. Therefore, we have selected All-trans Retinoic Acid (ATRA), active metabolites of vitamin A, which have both anti-inflammatory and mucosal adjuvant properties. Pre-treatment of ATRA significantly reduced CPMVs induced TLR2 mediated pro-inflammatory responses in vitro and in vivo. Furthermore, we also found ATRA pre-treatment significantly induced mucosal immune response and protective efficacy after two doses of oral immunization with CPMVs (75µg). This study can help to reduce OMV based vaccine toxicity and induce better protective immunity where children and men suffered from malnutrition mainly in developing countries.


Subject(s)
Bacterial Outer Membrane Proteins/immunology , Cholera Vaccines/immunology , Immunity, Mucosal , Inflammation/prevention & control , Tretinoin/administration & dosage , Vibrio cholerae/immunology , Administration, Oral , Animals , Animals, Newborn , Antibodies, Bacterial/blood , Bacterial Outer Membrane Proteins/toxicity , Cholera/immunology , Cholera/prevention & control , Cholera Vaccines/administration & dosage , Cholera Vaccines/toxicity , Cytokines/biosynthesis , Disease Models, Animal , Female , Immunogenicity, Vaccine , Immunoglobulin G/blood , Mice , Mice, Inbred BALB C , Toll-Like Receptor 2/immunology , Tretinoin/immunology , Tretinoin/pharmacology
14.
Jpn J Infect Dis ; 70(1): 111-114, 2017 Jan 24.
Article in English | MEDLINE | ID: mdl-27169940

ABSTRACT

Diabetes mellitus and diarrhea are becoming increasingly burdensome worldwide, particularly in developing countries such as India. Diabetic patients are susceptible to infection with pathogenic bacteria, particularly those causing invasive enteric infections. In this study, we observed changes in the pathophysiological features of mice with streptozotocin-induced hyperglycemia. In our experiments, both hyperglycemic and control mice were infected with pathogenic enteric bacteria-non-typhoidal Salmonella, Shigella flexneri, or Vibrio parahaemolyticus. Morbidity, mortality, and bacterial load were all higher in the diabetic mice than in the control mice, and the phagocytic and bactericidal activities of peritoneal macrophages isolated from hyperglycemic mice were lower than they were in the controls. We hypothesize that hyperglycemia leads to a downregulation of the innate immune response, which in turn increases vulnerability to enteric bacterial infection.


Subject(s)
Diabetes Mellitus, Experimental/complications , Diarrhea/epidemiology , Dysentery, Bacillary/epidemiology , Hyperglycemia/chemically induced , Hyperglycemia/complications , Salmonella Infections, Animal/epidemiology , Vibrio Infections/epidemiology , Animals , Antibiotics, Antineoplastic , Bacterial Load , Diarrhea/immunology , Disease Models, Animal , Disease Susceptibility , Dysentery, Bacillary/immunology , Macrophages, Peritoneal/immunology , Mice , Mice, Obese , Salmonella Infections, Animal/immunology , Streptozocin/administration & dosage , Survival Analysis , Vibrio Infections/immunology
15.
Biol Cybern ; 110(2-3): 229-36, 2016 06.
Article in English | MEDLINE | ID: mdl-27016101

ABSTRACT

The present work proposes a unified model to explain two previously reported properties of the Mach band illusion. The first is the frequently referenced fact that Mach bands are prominently visible at ramps, but practically vanish at intensity steps. The second property, less studied, on the other hand may also be related to the first. It concerns the fact that the width of the illusory Mach bands appears to be a function of the slope of the ramp itself. The model proposed here combines the difference of Gaussians (DOG) model of lateral inhibition in receptive fields with the models of feature detection, based on a holistic approach. The sharpness of discontinuity (SOD) concept for Mach band stimulus has been defined and is related to the slope of the ramp. It is suggested that calculation of SOD leads to an adaptive change in inhibitory surround, a notion that has the support of physiological experiments too.


Subject(s)
Illusions/physiology , Models, Neurological , Normal Distribution
16.
Vaccine ; 34(15): 1839-46, 2016 Apr 04.
Article in English | MEDLINE | ID: mdl-26878295

ABSTRACT

Our previous studies on outer membrane vesicles based vaccine development against shigellosis, revealed the inability of Shigella to release significant amount of vesicles naturally, during growth. Disruption of tolA, one of the genes of the Tol-Pal system of Gram negative bacterial membrane, has increased the vesicle release rate of a Shigella boydii type 4 strain to approximately 60% higher. We also noticed the vesicles, released from tolA-disrupted strain captured more OmpA protein and lipopolysaccharide, compared to the vesicles released from its wild type prototype. Six to seven weeks old BALB/c mice, immunized with 25 µg of three oral doses of the vesicles, released by tolA mutant, conferred 100% protection against lethal homologous challenge through nasal route, compared to only 60% protection after the same dose of wild type immunogen. Mice, immunized with the vesicles from tolA-mutant, manifested significant secretion of mucosal IgG and IgA. A sharp and significant response of pro-inflammatory cytokines (TNF-α, IL-6, IFN-γ) were also observed in the lung lavage of these groups of mice, within 6h post challenge; but at 24h, these inflammatory cytokines showed the sign of subsidence and the system was taken over by the release of anti-inflammatory cytokines (IL-4 and IL-10). Studies with naïve peritoneal macrophages, proved further, the potency of these vesicles to stimulate nitric oxide and TNF-α, IL-12p70, IL-6 and IL-10 productions in-vitro. The ability of these vesicles to trigger polarization of CD4(+) T cells toward Th1 adaptive immune response, had also been observed along with the presence of anti-inflammatory cytokines in the system. Our study demonstrated, the vesicles from tolA-disrupted Shigella were able to suppress Shigella-mediated inflammation in the host and could balance between inflammation and anti-inflammation, promoting better survival and health of the infected mice. Outer membrane vesicles from tolA-mutant, could be a potential cost-effective vaccine candidate against shigellosis.


Subject(s)
Extracellular Vesicles/immunology , Shigella Vaccines/immunology , Shigella boydii , Administration, Oral , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/chemistry , Bacterial Outer Membrane Proteins/immunology , Bronchoalveolar Lavage Fluid/chemistry , Cytokines/chemistry , Dysentery, Bacillary/prevention & control , Gene Knockout Techniques , Lung/immunology , Macrophages, Peritoneal/immunology , Mice, Inbred BALB C , Shigella boydii/genetics
17.
PLoS One ; 10(7): e0133445, 2015.
Article in English | MEDLINE | ID: mdl-26186449

ABSTRACT

Consumption of dietary carotenoids or carotenoid supplements can alter the color (yellowness) of human skin through increased carotenoid deposition in the skin. As fruit and vegetables are the main dietary sources of carotenoids, skin yellowness may be a function of regular fruit and vegetable consumption. However, most previous studies have used tablets or capsules to supplement carotenoid intake, and less is known of the impact of increased fruit and vegetable consumption on skin color. Here, we examined skin color changes in an Asian population (Malaysian Chinese ethnicity) over a six week dietary intervention with a carotenoid-rich fruit smoothie. Eighty one university students (34 males, 47 females; mean age 20.48) were assigned randomly to consuming either a fruit smoothie (intervention group) or mineral water (control group) daily for six weeks. Participants' skin yellowness (CIELab b*), redness (a*) and luminance (L*) were measured at baseline, twice during the intervention period and at a two-week follow-up, using a handheld reflectance spectrophotometer. Results showed a large increment in skin yellowness (p<0.001) and slight increment in skin redness (p<0.001) after 4 weeks of intervention for participants in the intervention group. Skin yellowness and skin redness remained elevated at the two week follow up measurement. In conclusion, intervention with a carotenoid-rich fruit smoothie is associated with increased skin redness and yellowness in an Asian population. Changes in the reflectance spectrum of the skin suggest that this color change was caused by carotenoid deposition in the skin.


Subject(s)
Beverages , Face/physiology , Fruit , Skin Pigmentation , Vegetables , Carotenoids/analysis , Chromatography, High Pressure Liquid , Diet , Female , Humans , Male , Spectrum Analysis , Young Adult
18.
Immunobiology ; 220(11): 1275-83, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26210044

ABSTRACT

Recently we have shown the homologous protective efficacy of heat killed multi-serotype Shigella (HKMS) immunogens in a guinea pig colitis model. In our present study, we have advanced our research by immunizing rabbits with a reduced number of oral doses and evaluating the host's adaptive immune responses. The duration of immunogenicity and subsequently protective efficacy was determined against wild type heterologous Shigella strains in a rabbit luminal model. After three successive oral immunizations with HKMS immunogens, serum and lymphocyte supernatant antibody titer against the heterologous shigellae were reciprocally increased and remained at an elevated level up to 180 days. Serogroup and serotype specific O-antigen of lipopolysaccharide and immunogenic proteins of heterologous challenge strains were detected by immunoblot assay. Up-regulation of IL-12p35, IFN-γ and IL-10 mRNA expression was detected in immunized rabbit peripheral blood mononuclear cells (PBMC) after stimulation with HKMS in vitro. HKMS-specific plasma cell response was confirmed by production of a relatively higher level of HKMS-specific IgG in immunized PBMC supernatant compared to control group. Furthermore, the immunized groups of rabbits exhibited complete protection against wild type heterologous shigellae challenge. Thus HKMS immunogens induced humoral and Th1-mediated adaptive immunity and provided complete protection in a rabbit model. These immunogens could be a broad spectrum non-living vaccine candidate for human use in the near future.


Subject(s)
Antigens, Bacterial/immunology , Dysentery, Bacillary/immunology , Dysentery, Bacillary/prevention & control , Immunity, Humoral , Immunization , Shigella/immunology , Adaptive Immunity , Administration, Oral , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Antibody Formation , Antigens, Bacterial/administration & dosage , Disease Models, Animal , Female , Immunity, Cellular , Immunoglobulin A, Secretory/blood , Immunoglobulin A, Secretory/immunology , Immunoglobulin Isotypes/blood , Immunoglobulin Isotypes/immunology , Male , Plasma Cells/immunology , Plasma Cells/metabolism , Rabbits , Serogroup , Shigella/classification
19.
Microbes Infect ; 17(3): 215-27, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25461799

ABSTRACT

Recently, we demonstrated oral immunizations with single serotype outer membrane vesicles of Vibrio cholerae induced serogroup specific protective immunity in the RITARD model. In our present study, we advanced our research by formulating multi-serotype outer membrane vesicles, mixing the OMVs of five virulent V. cholerae strains. Four doses of oral immunization with cholera pentavalent outer membrane vesicles (CPMVs) induced V. cholerae specific B and T cell responses. CPMVs-immunized mice generated long lasting serum IgG, IgA, IgM as well as mucosal sIgA and also elicited a higher percentage of CD4+ T cell distribution in spleen. Our study revealed that in vitro CPMVs-activated dendritic cells were secreting T cell polarizing cytokines, IL-12p40, IL-4, IL-6 and IL-1ß. Moreover, purified splenic CD4+ T cells of immunized mice also secreted IL-4, IL-13 and IL-17 cytokines, indicating the initiation of Th2 and Th17 cell mediated immune responses. CPMVs immunized adult female mice and their offspring were significantly protected from heterologous challenge with wild type V. cholerae. CPMVs could be exploited for the development of a novel non-living vaccine against circulating cholera in near future.


Subject(s)
Adaptive Immunity/immunology , Vaccines, Combined/immunology , Vibrio cholerae/physiology , Animals , Animals, Newborn , Cholera Vaccines , Female , Interleukin-12 Subunit p40/immunology , Interleukin-13/immunology , Interleukin-17/immunology , Interleukin-4/immunology , Interleukin-6/immunology , Mice , Models, Animal , Vibrio cholerae/immunology
20.
Jpn J Infect Dis ; 67(3): 221-6, 2014.
Article in English | MEDLINE | ID: mdl-24858614

ABSTRACT

An outbreak of cholera struck Bihar, an Indian state, in August 2008 following a massive flood. Here we report the phenotypic and genotypic characteristics of Vibrio cholerae strains isolated from patients with diarrhea. Rectal swabs were obtained from patients with diarrhea who were admitted to medical camps or the hospital, and the strains were biochemically and serologically characterized. V. cholerae was isolated from 21 (65.6%) of 32 rectal swabs. Serological studies revealed that all the 21 isolates belonged to V. cholerae O1 Ogawa. Mismatch amplification mutation assay (MAMA)-PCR showed that the isolates belonged to El Tor variant group, and pulsed-field gel electrophoresis (PFGE) proved that these isolates were of a different lineage than the conventional El Tor variant strains. These isolates were resistant to several drugs, including ampicillin, streptomycin, tetracycline, nalidixic acid, and furazolidone. The uniqueness of the current report arises from the fact that records of cholera in Bihar are availiable for the early 1960s but not for the next 4 decades. Moreover, the present study is the first to report a cholera outbreak in Bihar that was caused by an El Tor variant strain.


Subject(s)
Cholera/epidemiology , Cholera/microbiology , Disease Outbreaks/statistics & numerical data , Vibrio cholerae O1/isolation & purification , Diarrhea/microbiology , Disasters , Floods , Humans , India/epidemiology , Phenotype , Rectum/microbiology , Vibrio cholerae O1/classification , Vibrio cholerae O1/genetics
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