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Asian Subjects (asian + subject)

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Medical Sciences	100%

Selected Abstracts

Metabolic differences between Asian and Caucasian patients on clozapine treatment

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2007
Mythily Subramaniam
Abstract Objective To establish if there are ethnic differences in the various metabolic disturbances that are common with clozapine treatment. Method Forty subjects (20 Asians and 20 Caucasians) with a diagnosis of schizophrenia were recruited for the study. Clozapine blood levels as well as fasting blood glucose, lipid levels, and liver function tests were established. Other clinical parameters such as blood pressure and Body Mass Index (BMI) were recorded for each patient. Results The mean clozapine dose was significantly higher in the Caucasian subjects (432.5,±,194.7,mg) as compared to the Asian subjects (175.6,±,106.9,mg) (p,<,0.001) while the mean weight-corrected dose for Asian patients was lower (3.0,±,1.9 and 5.0,±,2.1,mg/kg, respectively, p,=,0.005). There were, however, no ethnic differences in the mean plasma clozapine concentration (415.3,±,185.8,ng/ml in Caucasians and 417.1,±,290.8,ng/ml in Asians). BMI were significantly higher in Caucasians, as were the number of subjects with hypertension; levels of hepatic enzymes were higher in the Asian group. Conclusions Not only are there pharmacokinetic differences between Asian and Caucasian patients receiving clozapine, but there may also be differential emergence of certain metabolic abnormalities like hypertension and weight gain in these two ethnic groups. However, the effects of life style including diet and exercise cannot be excluded. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Elevated lipoprotein (a) and apolipoprotein B to AI ratio in South Asian patients with ischaemic stroke,

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 11 2007
K. M. Sharobeem
Summary Background:, Stroke is a continuing cause of excess cardiovascular disease (CVD) mortality amongst migrants from the Indian subcontinent (South Asians) living in Britain. However, little is known about the dyslipidaemia associated with stroke in South Asians. In particular, the highly atherogenic lipoprotein (a) [Lp(a)] and high apolipoprotein (Apo) B to AI ratio are emerging risk factors for CVD. Methods:, Using a case,control study, we investigated features of the dyslipidaemia in South Asian patients with stroke compared with South Asian subjects with no history of clinically detectable stroke. We studied 55 consecutive South Asian patients with ischaemic stroke (confirmed on computerised scan of the brain) and 85 controls. Results:, The stroke patients were significantly older than controls (65.2 vs. 59.8 years, p = 0.001), but were similarly matched for male gender (63.6 vs. 61.2%), smoking habit (20.7 vs. 18.1%) and presence of type 2 diabetes (25.5 vs. 19.3%). There were no differences between serum total cholesterol (p = 0.07) and high-density lipoprotein cholesterol (p = 0.08) between the groups, but stroke patients had higher serum triglycerides (p = 0.005). Mean [95% confidence interval (CI)] Apo B to AI ratio was higher amongst stroke patients [1.0 (0.9,1.0) vs. 0.7 (0.7,0.75), p < 0.001]. Similarly, geometric mean serum Lp(a) was significantly higher (p = 0.037) in stroke patients [19.9 mg/dl (14.0,28.5)] vs. controls [15.1 mg/dl (11.4,20.1)]. On logistic regression, stroke was independently associated with age and Apo B to AI ratio (p < 0.01). Conclusion:, The present study suggests that Lp(a) and the Apo B to AI ratio are associated with ischaemic stroke in South Asians. A prospective analysis is needed to elucidate the role of Lp(a), Apo B and AI as risk factors for ischaemic stroke in this population, as well as the effects of intervention. [source]

Ethnic skin types: are there differences in skin structure and function?,

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 2 2006
A. V. Rawlings
Synopsis People of skin of colour comprise the majority of the world's population and Asian subjects comprise more than half of the total population of the earth. Even so, the literature on the characteristics of the subjects with skin of colour is limited. Several groups over the past decades have attempted to decipher the underlying differences in skin structure and function in different ethnic skin types. However, most of these studies have been of small scale and in some studies interindividual differences in skin quality overwhelm any racial differences. There has been a recent call for more studies to address genetic together with phenotypic differences among different racial groups and in this respect several large-scale studies have been conducted recently. The most obvious ethnic skin difference relates to skin colour which is dominated by the presence of melanin. The photoprotection derived from this polymer influences the rate of the skin aging changes between the different racial groups. However, all racial groups are eventually subjected to the photoaging process. Generally Caucasians have an earlier onset and greater skin wrinkling and sagging signs than other skin types and in general increased pigmentary problems are seen in skin of colour although one large study reported that East Asians living in the U.S.A. had the least pigment spots. Induction of a hyperpigmentary response is thought to be through signaling by the protease-activated receptor-2 which together with its activating protease is increased in the epidermis of subjects with skin of colour. Changes in skin biophysical properties with age demonstrate that the more darkly pigmented subjects retaining younger skin properties compared with the more lightly pigmented groups. However, despite having a more compact stratum corneum (SC) there are conflicting reports on barrier function in these subjects. Nevertheless, upon a chemical or mechanical challenge the SC barrier function is reported to be stronger in subjects with darker skin despite having the reported lowest ceramide levels. One has to remember that barrier function relates to the total architecture of the SC and not just its lipid levels. Asian skin is reported to possess a similar basal transepidermal water loss (TEWL) to Caucasian skin and similar ceramide levels but upon mechanical challenge it has the weakest barrier function. Differences in intercellular cohesion are obviously apparent. In contrast reduced SC natural moisturizing factor levels have been reported compared with Caucasian and African American skin. These differences will contribute to differences in desquamation but few data are available. One recent study has shown reduced epidermal Cathepsin L2 levels in darker skin types which if also occurs in the SC could contribute to the known skin ashing problems these subjects experience. In very general terms as the desquamatory enzymes are extruded with the lamellar granules subjects with lowered SC lipid levels are expected to have lowered desquamatory enzyme levels. Increased pores size, sebum secretion and skin surface microflora occur in Negroid subjects. Equally increased mast cell granule size occurs in these subjects. The frequency of skin sensitivity is quite similar across different racial groups but the stimuli for its induction shows subtle differences. Nevertheless, several studies indicate that Asian skin maybe more sensitive to exogenous chemicals probably due to a thinner SC and higher eccrine gland density. In conclusion, we know more of the biophysical and somatosensory characteristics of ethnic skin types but clearly, there is still more to learn and especially about the inherent underlying biological differences in ethnic skin types. Résumé, Les gens qui ont une peau de couleur représentent la majorité de la population mondiale et les sujets asiatiques en représentent plus de la moitié. Pourtant la littérature consacrée aux caractéristiques de ces sujets est limitée. Plusieurs groupes de travail ont essayé au cours des dernières années de comprendre les différences sous-jacentes de la structure et de la fonction de la peau de différentes ethnies. Maisla plupart de ces études ont été réalisées à petite échelle et dans certains cas les différences observées entre les individus au niveau de la qualité de la peau ne font pas ressortir de différence entre races. Récemment, un besoin d'études reliant les diffèrences génétiques et phénotypiques entre différents groupes raciaux s'est fait sentir et de ce fait beaucoup d'études à grande èchelle ont été entreprises. La différence la plus évidente, entre les peaux ethniques, est leur couleur liée à la présence de la mélanine. La photoprotection induite par ce polymère influence le taux de vieillissement de la peau entre les différents groupes raciaux qui finalement sont tous sujets au processus de photovieillissement. Généralement, les caucasiens ont des signes plus précoces et plus importants de formation de rides et de relâchement de la peau; en général, les problèmes d'augmentation de la pigmentation sont observés sur les peaux de couleur, bien qu'une grande étude ait rapporté que des sujets originaires de l'Asie de l'Est vivant aux U.S.A. avaient le moins de taches pigmentaires. On pense que la réponse d'une induction hyperpigmentaire est due à un signal envoyé par le récepteur 2 activé par une protéase. Le récepteur 2 augmente en même temps que la protéase activatrice dans l'épiderme des sujets ayant une peau de couleur. Les changements dans les propriètés biophysiques de la peau en fonction de l'âge montrent que les sujets qui ont la pigmentation la plus sombre gardent une peau plus jeune par comparaison aux groupes qui possèdent une pigmentation moins forte. Toutefois, bien qu'ayant un stratum corneum plus compact, il existe des rapports divergents sur la fonction barrière de ces sujets. Dans le cas d'agression chimique ou mécanique, la fonction barrière du stratum corneum est considérée plus forte chez les sujets à peau plus foncée, malgré leurs taux plus faibles encéramide. On doit garder à l'esprit que la fonction barrière du stratum corneum dépend de toute son architecture et pas seulement de sa teneur en lipides. On considère que la peau asiatique à unePIE (TEWL) basale similaire à la peau caucasienne, ainsi que des taux en céramides comparables, mais on constate que dans le cas d'agression mécanique, elle possède un effet barrière le plus faible. Des différences dans la cohésion intercellulaire sont évidentes. A contrario, on a mis en évidence des taux d'hydratation (NMF) plus faibles dans son stratum corneum, comparativement à la peau caucasienne et afro-américaine. Ces différences expliquent les variations au niveau de la desquamation, mais on a très peu de données sur ce sujet. Une étude récente a mis en évidence des taux réduits de Cathepsin L2 dans l'épiderme des types de peau plus sombre, ce qui, si cela se produisait dans le stratum corneum, expliquerait les problèmes biens connus de cendrage de la peau que ces sujets connaissent. En terme très gènéral, étant donné que les enzymes liées à la desquamation sont libérées avec les granules lamellaires, on s'attend à ce que les sujets ayant des taux de lipides faibles dans le stratum corneum aient des taux d'enzymes liés à la desquamation faibles. On constate chez les sujets noirs une augmentation de la taille des pores, de la sécrétion du sébum et de la microflore cutanée. On observe également chez ces sujets une augmentation de la taille des granules mastocellulaires. Le phénomène de peau sensible se retrouve à une fréquence similaire dans les différents groupes raciaux, mais il existe des différences subtiles dans lesstimuli nécessaires pour l'induire. En tout cas, plusieurs études montrent que la peau asiatique est peut-être plus sensible aux produits chimiques exogènes, ce qui probablement est dûà un stratum corneum plus mince et à une densité de glandes eccrines plus élevées. En conclusion, c'est sur les caractéristiques biophysiques et somato-sensorielles des différents types de peaux ethniques que nous en savons plus, mais il est clair qu'il nous reste à comprendre encore beaucoup de choses principalement sur leurs différences biologiques. [source]

Frequency of 530-bp deletion in Actinobacillus actinomycetemcomitans leukotoxin promoter region

MOLECULAR ORAL MICROBIOLOGY, Issue 5 2000
A. Contreras
Actinobacillus actinomycetemcomitans strains showing a 530-bp deletion in the promoter region of the leukotoxin gene operon elaborate high amounts of leukotoxin that may play a role in the pathogenesis of periodontal disease. This study used polymerase chain reaction detection to determine the occurrence of the 530-bp deletion in 94 A. actinomycetemcomitans strains from individuals of various ethnic backgrounds. Eleven blacks and one Hispanic subject but no Caucasian or Asian subjects showed the 530-bp deletion in the leukotoxin promoter region, suggesting that the deletion is mainly a characteristic of individuals of African descent. A. actinomycetemcomitans strains exhibiting a deletion in the leukotoxin promotor region occurred both in individuals having severe periodontitis and in adolescents revealing no evidence of destructive periodontal disease. [source]

A pilot study on the differences in wavefront aberrations between two ethnic groups of young generally myopic subjects

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2008
Alejandro Cerviño
Abstract A comparative population-based cross-sectional study design was used to examine the prevalence of wavefront patterns in two different ethnic groups, and the relationship of these patterns with ocular biometrics and gender. The Shin,Nippon SRW5000 open field autorefractor, the Wavefront Analysis Supported Customized Ablation (WASCA) wavefront analyser and the IOLMaster were used to determine wavefront aberrations, mean spherical equivalent (SE) refractive error and axial length (AL). Seventy-four eyes from 74 young healthy subjects (44 British Asians, 30 Caucasians; 36 men, 38 women; mean age 22.51 ± 3.89 years) with mean SE averaging ,1.90 ± 2.76 D (range ,10.88 to +2.19 D) were examined. Relationships between ethnicity, gender, AL and SE, against the wavefront high-order root mean square, and aberration components up to the fifth order, were assessed by using multiple regression and correlation analysis. AL on its own accounted for 4.7% of the variance in trefoil component (F1,72 = 4.602; p = 0.035), 13.7% of coma component (F1,72 = 12.536; p = 0.001), 6.1% of trefoil component (F1,72 = 5.705; p = 0.020) and 9.8% of coefficient (F1,72 = 8.908; p = 0.004). A significant model emerged (F2,71 = 6.164; p = 0.003) for ethnicity and axial length, accounting for 12.4% of variance in primary spherical aberration with ethnicity accounting for 8.4% of that variance. For Caucasian subjects, a significant correlation was found between axial length and (Pearson's correlation coefficient ,0.500; p = 0.005) and (Pearson's correlation coefficient ,0.423; p = 0.020). For British Asian subjects, AL was only correlated with coefficient (Pearson's correlation coefficient ,0.358; p = 0.017). Ethnicity is a factor to be considered in the variability of wavefront aberration, particularly spherical aberration. Relationship between AL and wavefront aberrations seems to vary between ethnicities. If higher order aberrations play a role in the emmetropization process, this may be different for different populations. [source]

The effect of ultraviolet B-induced vitamin D levels on host resistance to Mycobacterium tuberculosis: a pilot study in immigrant Asian adults living in the United Kingdom

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2 2008
Paul Devakar Yesudian
Summary Asian immigrants to the United Kingdom demonstrate much higher tuberculosis rates than the indigenous population. This is postulated to be because of their low vitamin D levels, consequent upon a combination of diet and their reduced ultraviolet (UV) exposure in the United Kingdom, because vitamin D enhances antimycobacterial activity in in vitro systems. The aim of this study was to examine the relationship between UVB exposure, vitamin D levels and tuberculo-immunity in Asian immigrants in the United Kingdom. Suberythemal UVB treatments were given to eight subjects on 3 consecutive days, using broadband UVB fluorescent lamps. Blood was sampled for 25-hydroxyvitamin D (25-OH D) and whole blood functional assays were performed for antimycobacterial immunity. The mean 25-OH D level increased from a baseline of 11.23 ng/ml (95% CI 6.7,20.39) to 20.39 ng/ml (95% CI 16.6,20) following UVB treatment, P<0.01. However, no significant change in antimycobacterial immunity occurred following UVB exposure. This pilot study in Asian subjects with good baseline tuberculo-immunity has not supported a role for UVB-induced 25-OH D in the immune response to Mycobacterium tuberculosis. [source]

Effect of Obesity on P-Wave Parameters in a Chinese Population

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2010
Ph.D., Tong Liu M.D.
Objective: To study the association between obesity and P-wave duration and dispersion (Pd) in order to evaluate the potential risk for atrial fibrillation development in Chinese subjects using the definitions applied for Asian populations. Methods: The study population consisted of 40 obese (body mass index (BMI) , 25 Kg/m2, according to the World Health Organization classification for the Asian population) subjects and 20 age- and sex-matched normal weight controls. Maximum P-wave duration (Pmax), minimum P-wave duration (Pmin), and Pd were carefully measured using a 12-lead electrocardiogram, while the presence of interatrial block (IAB; P , 110 ms) was assessed. Results: There were no significant differences between the two groups regarding age, sex, history of hypertension or diabetes, and hyperlipidemia. Compared to controls, BMI, left atrial diameter (LAD), and interventricular septal thickness were increased, while Pmax (111.9 ± 9.3 vs 101.1 ± 6.0 ms, P < 0.01) and Pd (47.9 ± 9.3 vs 31.8 ± 6.9 ms, P < 0.01) were significantly prolonged in the obese group. Pmin was similar between the two groups. The prevalence of IAB was significantly greater in the obese subjects. Pearson's correlation analysis showed that there were positive correlations between Pd and BMI (r = 0.6, P < 0.001), as well as between Pd and LAD (r = 0.366, P < 0.05). Conclusion: Our data suggest that obesity is associated with increased Pmax and Pd, and increased prevalence of IAB, parameters that have been associated with atrial fibrillation. The correlation of these electrocardiogram parameters with LAD indicates an association between increased BMI and atrial remodeling in Asian subjects. Ann Noninvasive Electrocardiol 2010;15(3):259,263 [source]

Effect of age on anterior chamber angle configuration in Asians determined by anterior segment optical coherence tomography; clinic-based study

ACTA OPHTHALMOLOGICA, Issue 6 2010
Mi Hyun Cheon
Acta Ophthalmol. 2010: 88: e205,e210 Abstract. Purpose:, To evaluate the distribution of anterior chamber angle (ACA) parameters and to assess association of these parameters with age in Asian subjects. Methods:, Four hundred and thirty-nine consecutive Korean subjects aged from 30 to 89 were enrolled from a university clinic. All participants were scanned using anterior segment optical coherence tomography (AS-OCT, Visante, version 2.0). We measured ACA parameters such as anterior chamber depth (ACD), angle opening distance at 500 and 750 ,m (AOD500,750), angle recess area at 500 and 750 ,m (ARA500,750), trabecular iris space area at 500 and 750 ,m (TISA500,750), and determined age-related changes in these parameters with use of a linear mixed effect model that adjusted for gender, axial length, intraocular pressure, and keratometry data. Slopes of ACA parameters as a function of age were determined. For various AS-OCT parameters, the normalized slope was calculated by dividing the slope by the mean value. Results:, All analysed ACA parameters decreased with age in both nasal and temporal quadrants. Axial length and keratometry data were significant covariates for ACA changes. The slopes of ACD were ,0.02396 mm/year, AOD500, ARA500, and TISA500 measured at the temporal angle were ,0.00634 mm/year, ,0.0019 mm2/year, and ,0.00177 mm2/year, respectively. There was no age-dependent difference in central corneal thickness (p value; 0.4597) Based on the normalized slopes, the AOD showed the steepest slope at both temporal and nasal sectors. Conclusion:, All ACA parameters assessed by AS-OCT, which accounted for other ocular biometric parameters, showed significant negative slopes with increasing age. These results should be considered when assessing changes in the anterior chamber over time. [source]