Asian population frequencies and haplotype distribution of killer cell immunoglobulin-like receptor (KIR) genes among Chinese, Malay, and Indian in Singapore

Killer cell immunoglobulin-like receptors (KIR) gene frequencies have been shown to be distinctly different between populations and contribute to functional variation in the immune response. We have investigated KIR gene frequencies in 370 individuals representing three Asian populations in Singapore and report here the distribution of 14 KIR genes (2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) with two pseudogenes (2DP1, 3DP1) among Singapore Chinese (n = 210); Singapore Malay (n = 80), and Singapore Indian (n = 80). Four framework genes (KIR3DL3, 3DP1, 2DL4, 3DL2) and a nonframework pseudogene 2DP1 were detected in all samples while KIR2DS2, 2DL2, 2DL5, and 2DS5 had the greatest significant variation across the three populations. Fifteen significant linkage patterns, consistent with associations between genes of A and B haplotypes, were observed. Eighty-four distinct KIR profiles were determined in our populations, 38 of which had not been described in other populations. KIR haplotype studies were performed using nine Singapore Chinese families comprising 34 individuals. All genotypes could be resolved into corresponding pairs of existing haplotypes with eight distinct KIR genotypes and eight different haplotypes. The haplotype A2 with frequency of 63.9% was dominant in Singapore Chinese, comparable to that reported in Korean and Chinese Han. The A haplotypes predominate in Singapore Chinese, with ratio of A to B haplotypes of approximately 3:1. Comparison with KIR frequencies in other populations showed that Singapore Chinese shared similar distributions with Chinese Han, Japanese, and Korean; Singapore Indian was found to be comparable with North Indian Hindus while Singapore Malay resembled the Thai. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Underweight Full-Term Indian Neonates Show Differences in Umbilical Cord Blood Leukocyte Phenotype: A Cross-Sectional Study

Background

While infections are a major cause of neonatal mortality in India even in full-term neonates, this is an especial problem in the large proportion (~20%) of neonates born underweight (or small-for-gestational-age; SGA). One potential contributory factor for this susceptibility is the possibility that immune system maturation may be affected along with intrauterine growth retardation.

Methods

In order to examine the possibility that differences in immune status may underlie the susceptibility of SGA neonates to infections, we enumerated the frequencies and concentrations of 22 leukocyte subset populations as well as IgM and IgA levels in umbilical cord blood from full-term SGA neonates and compared them with values from normal-weight (or appropriate-for-gestational-age; AGA) full-term neonates. We eliminated most SGA-associated risk factors in the exclusion criteria so as to ensure that AGA-SGA differences, if any, would be more likely to be associated with the underweight status itself.

Results

An analysis of 502 such samples, including 50 from SGA neonates, showed that SGA neonates have significantly fewer plasmacytoid dendritic cells (pDCs), a higher myeloid DC (mDC) to pDC ratio, more natural killer (NK) cells, and higher IgM levels in cord blood in comparison with AGA neonates. Other differences were also observed such as tendencies to lower CD4:CD8 ratios and greater prominence of inflammatory monocytes, mDCs and neutrophils, but while some of them had substantial differences, they did not quite reach the standard level of statistical significance.

Conclusions

These differences in cellular lineages of the immune system possibly reflect stress responses in utero associated with growth restriction. Increased susceptibility to infections may thus be linked to complex immune system dysregulation rather than simply retarded immune system maturation.     

Ethnic and sub-ethnic attachments among Chinese,Korean, and Indian immigrants in New York City

This article compares ethnic and sub-ethnic attachments in Chinese, Indian, and Korean immigrants in New York City, based on results of a survey. Indian respondents, with much higher levels of education and fluency in English, show a lower level of cultural ethnic attachment than the other two groups. The Chinese show the lowest level of formal ethnic affiliation, mainly due to their much lower level of religious affiliation. All three groups show extremely high levels of informal ethnic networks. However, Chinese and Indian respondents largely limit their close friendships to their sub-ethnic group, based on national origin, religion, regional origin and/or language, while Korean respondents, characterized by group homogeneity, tend to maintain close friendships with all other Koreans. Much larger proportions of Chinese and Indian respondents than Koreans choose the sub-ethnic identity label and they show much lower levels of loyalty to their homeland than Korean respondents.     

乐昌含笑不同家系的叶形态与生长差异分析

为了解乐昌含笑(Michelia chapensis)叶形态和生长性状的家系变异特征,对15个家系的叶形态性状和生长指标及其相关性进行了分析.结果表明,乐昌含笑叶片形态在家系间和家系内均存在显著差异,不同家系间以帽子峰家系叶形态的平均变异系数最大(23.55％),乐九5家系的最小(12.63％);不同叶形态性状间以干物...     

Population genetic analysis among five Indian population groups using six microsatellite markers

Genetic variation at six tetranucleotide microsatellites (HUMTHO1, HUMVWA, F13A01, D3S1359, D12S66, and D12S67) has heen determined in five endogamous ethnic population groups of India belonging to two major linguistic families. The populations analyzed were Konkanastha Brahmins and Marathas (Maharashtra state) from the Indo-Aryan linguistic family and Nairs, Ezhavas, and Muslims (Kerala state) from the Dravidian family. All six loci show high gene diversity, ranging from 0.63 +/- 0.04 to 0.84 +/- 0.02. The average GST value observed was 1.7%, indicating that the differences between the populations account for less than 2% of the diversity, while the genetic variation is high within the five population groups studied (>98%). The phylogenetic tree fails to show any clear cluster. The absence of any cluster along with low average GST is suggestive of substantial genetic similarity among the studied populations, in spite of clear geographical, linguistic, and cultural barriers. This similarity indicates either a greater gene flow between these groups or, alternatively, may reflect a recent evolution for them, considering that the Indian caste system evolved only about 3000 years ago.     

Population structure of Helicobacter pylori among ethnic groups in Malaysia: recent acquisition of the bacterium by the Malay population

Background  

Helicobacter pylori is a major gastric bacterial pathogen. This pathogen has been shown to follow the routes of human migration by their geographical origin and currently the global H. pylori population has been divided into six ancestral populations, three from Africa, two from Asia and one from Europe. Malaysia is made up of three major ethnic populations, Malay, Chinese and Indian, providing a good population for studying recent H. pylori migration and admixture.     

Brain Morphology in Children with Epilepsy and ADHD

Background

Attention deficit hyperactivity disorder (ADHD) is a common comorbidity of childhood epilepsy, but the neuroanatomical correlates of ADHD in epilepsy have yet to be comprehensively characterized.

Methods

Children with new and recent-onset epilepsy with (n = 18) and without (n = 36) ADHD, and healthy controls (n = 46) underwent high resolution MRI. Measures of cortical morphology (thickness, area, volume, curvature) and subcortical and cerebellar volumes were compared between the groups using the program FreeSurfer 5.1.

Results

Compared to the control group, children with epilepsy and ADHD exhibited diffuse bilateral thinning in the frontal, parietal and temporal lobes, with volume reductions in the brainstem and subcortical structures (bilateral caudate, left thalamus, right hippocampus). There were very few group differences across measures of cortical volume, area or curvature.

Conclusions

Children with epilepsy and comorbid ADHD exhibited a pattern of bilateral and widespread decreased cortical thickness as well as decreased volume of subcortical structures and brainstem. These anatomic abnormalities were evident early in the course of epilepsy suggesting the presence of antecedent neurodevelopmental changes, the course of which remains to be determined.     

Molecular Epidemiology of Amoebiasis: A Cross-Sectional Study among North East Indian Population

Background

Epidemiological studies carried out using culture or microscopy in most of the amoebiasis endemic developing countries, yielded confusing results since none of these could differentiate the pathogenic Entamoeba histolytica from the non-pathogenic Entamoeba dispar and Entamoeba moshkovskii. The Northeastern part of India is a hot spot of infection since the climatic conditions are most conducive for the infection and so far no systemic study has been carried out in this region.

Methodology/Principal Findings

Following a cross-sectional study designed during the period 2011–2014, a total of 1260 fecal samples collected from the Northeast Indian population were subjected to microscopy, fecal culture and a sensitive and specific DNA dot blot screening assay developed in our laboratory targeting the Entamoeba spp. Further species discrimination using PCR assay performed in microscopy, culture and DNA dot blot screening positive samples showed E. histolytica an overall prevalence rate of 11.1%, 8.0% and 13.7% respectively. In addition, infection rates of nonpathogenic E. dispar and E. moshkovskii were 11.8% (95% CI = 10.2, 13.8) and 7.8% (95% CI = 6.4, 9.4) respectively. The spatial distributions of infection were 18.2% (107/588) of Assam, 11.7% (23/197) of Manipur, 10.2% (21/207) of Meghalaya, and 8.2% (22/268) of Tripura states. Association study of the disease with demographic features suggested poor living condition (OR = 3.21; 95% CI = 1.83, 5.63), previous history of infection in family member (OR = 3.18; 95% CI = 2.09, 4.82) and unhygienic toilet facility (OR = 1.79; 95% CI = 1.28, 2.49) as significant risk factors for amoebiasis. Children in age group <15 yr, participants having lower levels of education, and daily laborers exhibited a higher infection rate.

Conclusions/Significance

Despite the importance of molecular diagnosis of amoebiasis, molecular epidemiological data based on a large sample size from endemic countries are rarely reported in the literature. Improved and faster method of diagnosis employed here to dissect out the pathogenic from the nonpathogenic species would help the clinicians to prescribe the appropriate anti-amoebic drug.     

Differences among Yanomama Indian villages: Do the patterns of allele frequencies,anthropometrics and map locations correspond?

In order to determine the degree of correspondence between sets of multivariate observations based on different kinds of traits, two new methods, derived from fundamentally different notions of “correspondence,” are adopted here and compared. Using networks or trees to represent contemporary relationships, the first method tests the similarity of the cluster or hierarchic structures implicit in two sets of data. The second approach tests the departure from perfect geometric congruence or superimposability. Computer simulation was used to generate the distributions needed for significance tests under the null hypothesis. By the first technique, we find significant correspondence among the cluster structures for geographic, allele frequency, and anthropometric data on 19 Yanomama Indian villages. The results are similar and more precise for a subset consisting of seven villages. Some of these results differ from the conclusions which would be reached with the conventional correlations based upon entries in distance tables. The direct test of congruence, used only for the data on the subset of seven villages, gives results which differ substantially from those based on cluster-structure. There are, however, similarities between the measure of congruence and the simple correlations based on entries in the distance tables. The significant correspondences observed call for some explanation. Cultural and demographic features determine the particular non-random allocation of individuals to village fragments when a village splits. These social phenomena are invoked in tentative explanation of the agreement among historical, biological, and geographic relationships of villages.     

Lesion Activity on Brain MRI in a Chinese Population with Unilateral Optic Neuritis

Longitudinal studies have shown that brain white matter lesions are strong predictors of the conversion of unilateral optic neuritis to multiple sclerosis (MS) in Caucasian populations. Consequently brain MRI criteria have been developed to improve the prediction of the development of clinically definite multiple sclerosis (CDMS). In Asian populations, optic neuritis may be the first sign of classical or optic-spinal MS. These signs add to the uncertainty regarding brain MRI changes with respect to the course of unilateral optic neuritis. The aim of this study was to examine the association between brain lesion activity and conversion to CDMS in Chinese patients with unilateral optic neuritis. A small prospective cohort study of 40 consecutive Chinese patients who presented with unilateral optic neuritis was conducted. Brain lesion activity was recorded as the incidence of Gd-enhanced lesions and new T2 lesions. Brain lesions on MRI that were characteristic of MS were defined according to the 2010 revisions of the McDonald criteria. The primary endpoint was the development of CDMS. We found that nineteen patients (48%) had brain lesions that were characteristic of MS on the initial scan. One of these patients (3%) had Gd-enhanced brain lesions. A significantly lower percentage of the patients (10%, p<0.001) presented with new T2 brain lesions on the second scan. During a median of 5 years of follow-up, seven patients (18%) developed CDMS. There was no significant difference in the conversion rate to CDMS between patients with and without brain lesions that were characteristic of MS (4/19 and 3/21, respectively; Fisher exact test, one-sided, p = 0.44). We conclude that brain lesions characteristic of MS are common in Chinese patients with unilateral optic neuritis; however, these patients exhibit low lesion activity. The predictive value of brain lesion activity for CDMS requires investigation in additional patients.     

Population genetic structure and conservation implications of Ceriops decandra in Malay Peninsula and North Australia

Comprehensive information of mangrove genetic resources is requisite for developing strategies for their effective conservation and sustainable use. Genetic diversity within and among populations of a widespread viviparous mangrove Ceriops decandra was determined using inter-simple sequence repeat (ISSR). Ten natural populations were collected from Malay Peninsula and North Australia. At the species level, high genetic variation was detected (P = 72%, H_E = 0.253, and I = 0.379). The estimate of G_ST was 0.882, indicating a high level of genetic differentiation among populations. When populations were grouped according to geographic regions, i.e., East Malaya, West Malaya, Southmost Malaya, and North Australia, AMOVA suggested that most of the total variation (87%) was accounted for by differentiation between regions, with only 4% accounting for variation among populations within regions, and a further 9% partitioned among individuals within a population. A UPGMA dendrogram based on genetic distance revealed a deep split between populations from the eastern Indian Ocean and all others from the western Pacific Ocean, which may result from the historical lowering of sea level at these regions during the recent Pleistocene glaciations. An understanding of the genetic structure of C. decandra provides insight for the conservation and management of this species.     

Gender Differences in the Prevalence and Development of Metabolic Syndrome in Chinese Population with Abdominal Obesity

Background

Not all the people with metabolic syndrome (MS) have abdominal obesity (AO). The study aimed to investigate gender differences in the prevalence and development of MS in Chinese population with abdominal obesity, which has rarely been reported.

Methods

Data were obtained from the 2007-08 China National Diabetes and Metabolic Disorders Study, and participants were divided into two samples for analysis. Sample 1 consisted of 19,046 people with abdominal obesity, while sample 2 included 2,124 people meeting pre-specified requirements. Survival analysis was used to analyze the development of MS.

Results

The age-standardized prevalence of MS in Chinese population with AO was 49.5%. The prevalence in males (73.7%) was significantly higher than that in females (36.9%). Males had significantly higher proportions of combinations of three or four MS components than females (36.4% vs. 30.2% and 18.4% vs. 5%, respectively). MS developed quick at first and became slow down later. Half of the participants with AO developed to MS after 3.9 years (95% CI: 3.7–4.1) from the initial metabolic abnormal component, whereas 75% developed to MS after 7.7 years (95% CI: 7.5–7.9).

Conclusion

Compared with females, Chinese males with AO should receive more attention because of their higher prevalence of MS and its components, more complex and risky combinations of abnormal components, and faster development of MS.     

Glutathione-S-Transferase Activity in the Brain: Species, Sex, Regional, and Age Differences

Abstract: Glutathione- S -transferase activity in the brain of male mammals (rat and mouse) was found to be relatively lower than in that of females. In contrast, the male aves (pigeon, kite, vulture, and crow) exhibited comparatively higher activity of brain glutathione- S -transferase than the corresponding females. Postnatal development of cytosolic glutathione-S-transferase activity in the rat brain was also investigated. The day-7 rats showed a low activity of 48 nmol/min/mg protein that gradually increased 3.2-fold over the age of 28 days. No striking differences in brain enzyme activities were observed between the 35- and 90-day-old rats. Discrete brain regions of immature rats were found to possess considerable but lower quantities of glutathione- S -transferase activity than those of the adults. The activity increased with the onset of development and attained a steady state after 21 days of age.     

Morphology,Oviposition, and Embryogenesis in an Australian Population of Acrobeloides nanus

A population of Acrobeloides nanus in Australia is described and illustrated, based on light and scanning electron microscopy. Embryogenesis from egg laying to hatching is followed over a wide range of temperatures. At 15 C, hatching occurs in about 125 hours and at 35 and 37.5 C after about 40 hours. At 40 C, egg development ceases early in cleavage. The capacity of A. nanus to develop over such a range of temperatures, and its anhydrobiotic capabilities, are discussed in relation to its survival and wide distribution in Australia.     

Regionaland Interspecies Differences in Brain Progesterone Metabolism

Metabolites of [³H]progesterone were studied in slices prepared from different brain regions of male rat, mouse, and monkey. The major metabolites were 5α-dihydroprogesterone (5α-DHP) and 3α,5α-tetrahydroprogesterone (3α,5α-THP) in rat brain slices, 5α-DHP and 20α- dihydroprogesterone (20α-DHP) in mouse brain slices, and 20α-DHP in monkey brain slices. In rat olfactory bulb slices, 5α-DHP represented 25.2 ± 3.3% of total radioactivity and 3α,5α-THP 17.5 ± 2.8%, whereas in rat medulla oblongata slices, 5α-DHP was 31.3 ± 3.5% and 3α,5α- THP 5.4 ± 1.5% of total radioactivity. In slices from other rat brain regions, both metabolites represented 12–20% of total radioactivity.-The highest metabolite content in mouse brain was also detected in olfactory bulb slices, where 5α-DHP represented 16.6 ± 4.6% and 20α-DHP 9.5 ± 2.3% of total radioactivity. In cortical and corpus callosum slices of monkey brain, 26.8 ± 4.4% and 2.4 ± 0.5% of total radioactivity, respectively, were converted to 20α-DHP, and less than 3% of total radioactivity could be attributed to any of the other metabolites detected. The 3α,α-THP content in both rat and monkey brain was below 1 nM, but increased in rat brain to 6.7 ± 2.5 nM after electroshock. Endogenous 3α,5α-THP might play an important role in the regulation of rat behavior through the modulation of GABA action on the GABA_A receptor. The significant interspecies differences in the brain progesterone metabolism should be considered in evaluating the functional role of neurosteroids in various species.     

Individual Differences in Fornix Microstructure and Body Mass Index

The prevalence of obesity and associated health conditions is increasing in the developed world. Obesity is related to atrophy and dysfunction of the hippocampus and hippocampal lesions may lead to increased appetite and weight gain. The hippocampus is connected via the fornix tract to the hypothalamus, orbitofrontal cortex, and the nucleus accumbens, all key structures for homeostatic and reward related control of food intake. The present study employed diffusion MRI tractography to investigate the relationship between microstructural properties of the fornix and variation in Body Mass Index (BMI), within normal and overweight ranges, in a group of community-dwelling older adults (53–93 years old). Larger BMI was associated with larger axial and mean diffusivity in the fornix (r = 0.64 and r = 0.55 respectively), relationships that were most pronounced in overweight individuals. Moreover, controlling for age, education, cognitive performance, blood pressure and global brain volume increased these correlations. Similar associations were not found in the parahippocampal cingulum, a comparison temporal association pathway. Thus, microstructural changes in fornix white matter were observed in older adults with increasing BMI levels from within normal to overweight ranges, so are not exclusively related to obesity. We propose that hippocampal-hypothalamic-prefrontal interactions, mediated by the fornix, contribute to the healthy functioning of networks involved in food intake control. The fornix, in turn, may display alterations in microstructure that reflect weight gain.     

Creating Rat Model for Hypoxic Brain Damage in Neonates by Oxygen Deprivation

Current study explores the feasibility of using a non-surgical method of oxygen deprivation to create Hypoxic brain damage in neonatal rats for medical studies. 7-day-old Sprague Dowley (SD) rats were kept in a container with low oxygen level (8%) for 1.5h. A second group had bilateral cephalic artery ligation before the 1.5h-low oxygen treatment, a method similar to the popular Rice method, to expose the brain to both hypoxic and ischemic situations. Short term neural functions and brain water weights were evaluated 1 day after the hypoxic treatment. Brain pathology and histology were also examined at 1 day and 3 days after the hypoxic treatment. Both groups showed impaired neural functions and increased brain water weight compared to the controls. Histology studies also revealed injuries in the subcortex, hippocampus and lateral ventricle in the brains from both groups. There is no significant difference in the degree of brain damages observed in the two groups. Our work demonstrated that oxygen deprivation alone is sufficient to cause brain damages similar to those seen in Hypoxic-ischemic brain disease (HIBD). Because this method avoids the invasive surgical procedure and therefore reduces the stress and mortality of laboratory animals during the experiment, we recommend it to be the favorable method for creating rat models for HIBD studies.     

Synaptosomes from Rat Brain: Morphology, Compartmentation, and Transmembrane pH and Electrical Gradients

Abstract: Morphological studies of synaptosomes isolated from rat brains show that approximately 68% of the synaptosomes in these preparations contain synaptic vesicles (range, 62–72.5%). Approximately 30% of the synaptosomes contain mitochondria, and only less than 20% of the total mitochondria in good preparations are free and not enclosed in synaptic structures. The mitochondrial volume percent calculated on the basis of the measured cytochrome c content is 5% for synaptosomes isolated from anesthetized animals and 11% for synaptosomes isolated from unanesthetized animals. These numbers bracket the value of 8.7% obtained from electron micrographs. The volume percent of intrasynaptic vesicles is 1.5% as calculated from electron micrographs. The pH gradient between the extracellular pH and the mean intracellular pH is -0.45, as measured by equilibrium distributions of methylamine and dimethylamine, and -0.05, as determined by equilibrium distributions of 5,5-dimethyloxazolidine-2,4-dione and trimethylacetic acid. Analysis of these data shows that there cannot be a large pH gradient (alkaline inside) across the mitochondria, nor can the synaptic vesicle compartment be very large (<1.85%). Equilibrium distribution of [³H]triphenylmethyl-phosphonium ion in synaptosomal preparations gives a calculated apparent potential of -85 mV, in agreement with our previous value. Analysis of these data using the measured volumes of mitochondrial and intrasynaptic vesicular compartments (8.7 and 1.5%, respectively) gives a maximum possible trans mitochondrial membrane potential of -59 mV.