Prevalence and avidity of human herpesvirus-6 specific IgG antibodies in pregnant women in Hungary

The prevalence, the level and the avidity of human herpesvirus-6 (HHV-6) specific IgG were examined in pregnant women and age-matched female blood donors. The study group consisted of 180 women (age 14-45); 60 women with normal pregnancy, 60 pregnant women with fetuses suspected of having any viral infection and 60 healthy blood donors with no history of pregnancy. Plasma or serum samples were tested for HHV-6 IgG antibodies by an immunofluorescence assay. Ninety-eight percent of blood donors and 97% of 120 pregnant women had IgG antibodies to HHV-6. The rate of seropositivity in women with normal pregnancies and women with fetuses suspected to have viral infection was the same. Pregnant women (n = 120) had significantly lower antibody titer than blood donors. No significant differences were found in the same respect between the two groups of pregnant women. Low avidity of IgG antibodies to HHV-6 was detected in 5% of pregnant women.     

Prevalence of antibodies to Chlamydia trachomatis in healthy population groups in Manitoba.

The prevalence of antibodies to Chlamydia trachomatis was determined in 1877 serum samples from healthy population groups of Caucasians, native Indians and recent Vietnamese immigrants in Manitoba. Testing was done with a commercially available immunofluorescence kit containing C. trachomatis antigen. The presence of antibodies was age-related; a progressive increase in prevalence was observed in children aged 1 to 15 years, and the overall prevalence was higher in female Caucasian blood donors and female Vietnamese immigrants than in males in both groups. However, there was no sex-related difference in prevalence among the subjects undergoing premarital testing or among the native Indians. Antibodies were more prevalent (p less than 0.001) in pregnant than in nonpregnant women matched for race and age, and a relatively high prevalence (66.6%) was found in the cord serum of newborns. The overall prevalence rate of antibodies in all Manitobans was 48.8% (44.9% in men, 55.9% in women and 35.3% in children.     

Salivary proline-rich protein polymorphisms in Chinese, Malays and Indians in Singapore

Salivary proline-rich protein (PRP) polymorphism, PRH1, PRH2, Ps, Pm (PmF), PmS and Gl, were investigated in three ethnic groups in Singapore: Chinese, Malays and Indians. The phenotype and gene frequencies were presented and comparison with other ethnic groups was made. The As protein, which was recently found in Japanese but not in Caucasians as a new allelic product of the PRH1 locus, was also observed in Chinese and Malays but not in Indians. Another allelic product (Ps4) of Ps protein polymorphism was found in Malays but not in Chinese and Indians. The results indicate the usefulness of salivary PRP polymorphism as markers in population genetic studies.     

Detection of human herpesvirus 6 and 7 DNA in saliva from healthy adults from Rio de Janeiro, Brazil

In this study, we aimed to evaluate virus shedding in the saliva of healthy adults from the metropolitan region of the city of Rio de Janeiro, Brazil, in order to verify the prevalence of both human herpesviruses 6 and 7 (HHV-6, HHV-7). The studied group comprised 182 healthy individuals at Pedro Ernesto University Hospital, who were being seen for annual odontologic revisions. Saliva specimens were subjected to a multiplex polymerase chain reaction (PCR) to detect the presence of HHV-6A, HHV-6B and HHV-7. The total Roseolovirus DNA prevalence was 22.4%. The PCR detected a HHV-6 prevalence of 9.8%, with HHV-6A detected in 7.1% of the samples and HHV-6B in 2.7%. HHV-7 DNA was revealed in 12.6% of the studied cases. Multiple infections caused by HHV-6A and 7 were found in 2.1% of the samples. No statistical differences were observed regarding age, but for HHV-7 infection, an upward trend was observed in female patients. Compared to studies from other countries, low prevalence rates of herpesvirus DNA were detected in saliva from the healthy individuals in our sample. PCR methodology thus proved to be a useful tool for Roseolovirus detection and it is important to consider possible geographic and populations differences that could explain the comparatively low prevalence rates described here.     

Seroprevalence of human herpesvirus 6 infection in Brazilian and Japanese populations in the north-east of Brazil.

The seroprevalence of human herpesvirus 6 (HHV-6) infection was examined for 434 Brazilians and 250 Japanese immigrants living in Recife and its vicinity, in the North-East of Brazil. A total of 684 sera from the healthy individuals were screened for IgG antibodies to HHV-6 by anticomplement immunofluorescence (ACIF) test. The seropositivity rate to HHV-6 showed little difference between the two groups: namely, it was 76.5% for Brazilians and 77.2% for Japanese immigrants. The seropositivity rate was constantly higher in females than in males. The high prevalence of anti-HHV-6 antibodies among children indicates that HHV-6 infection occurs very early in life.     

Restriction fragment length polymorphism (RFLP) at the DNF15S2 locus in three ethnic groups of Singapore

Three different ethnic groups from Singapore comprising 79 Chinese, 34 Malays and 23 Indians of Dravidian origin, were investigated for the HindIII RFLP at the DNF15S2 locus. The three populations had very similar allele frequencies and the frequency of rarer(S) allele was significantly (p less than 0.01) lower (0.21) in these ethnic groups compared to that in Caucasians (0.41). The phenotypic distributions were at Hardy-Weinberg equilibrium.     

Glucose dehydrogenase polymorphism among ethnic groups of Singapore--with report of two additional alleles (GDH4 and GDH5).

Placental glucose dehydrogenase (GDH; E.C.1.1.1.47) polymorphism was studied in 254 Chinese, 104 Malays, and 47 Indians from Singapore using isoelectric focusing. There is suggestive evidence of two additional anodal alleles (GDH4 and GDH5) in addition to the three alleles described in earlier studies. Altogether, 14 phenotypes have been observed in the present investigation, compared with six phenotypes described in earlier studies. It appears that placental GDH is controlled by five codominant autosomal alleles producing 15 possible phenotypes. The gene frequencies of GDH1, GDH2, and GDH3 in these ethnic groups are significantly different from those reported in Caucasians. There were slight differences in the gene frequencies between the three ethnic groups, with those of Indians being nearer to the frequency in Caucasians. In general, the distribution of GDH phenotypes was at Hardy-Weinberg equilibrium in all three ethnic groups studied.     

IgM neutralizing antibody responses to human herpesvirus-6 in patients with exanthem subitum or organ transplantation.

The assay for detecting IgM neutralizing (NT) antibody activity to human herpesvirus-6 (HHV-6) was developed by using pretreatment of blood sample with staphylococcal protein A. The activity was mostly present in IgM fractions of serum but not in IgA fractions separated by ultracentrifugation. The assay was used for seroepidemiological studies for HHV-6 infection. In primary HHV-6 infection, IgM NT antibodies appeared 5 to 7 days after onset of exanthem subitum, reached maximum titers at 2 to 3 weeks, and tended to decline to undetectable levels after 2 months. In contrast, reactivation of HHV-6 observed in organ transplants showed somewhat greater degree of IgM NT antibody responses that persisted for 2 to 3 months and became undetectable 5 to 6 months after transplantation. The level and persistence of NT antibody titers measured by the conventional method was generally greater than those of the IgM titers. The prevalence of the IgM NT antibodies was examined in healthy individuals. The antibody was first detected at 4 to 7 months of age (5%), reached maximum level at 8 to 11 months (40%), and was detectable by 4 to 6 years (17%). A few (4 to 5%) of adolescents and adults were positive for the antibody.     

Prevalence of Human Herpesvirus 6 Variants A and B in Patients with Chronic Fatigue Syndrome

Peripheral blood mononuclear cells collected from 13 patients with chronic fatigue syndrome and 13 healthy controls were analyzed for the presence of human herpesvirus 6 (HHV-6) DNA by variant-specific polymerase chain reaction and dot blot hybridization. HHV-6 DNA was detected in 7 of 13 (53%) patients, and of those 7 patients, 4 were positive for HHV-6 variant A DNA and 3 were for variant B. No HHV-6 DNA was detected in the controls. Serum antibody titers to the late antigen and antibody prevalence to the early antigen of HHV-6 were significantly higher in the patient group. These results suggest active replication of HHV-6 in patients with chronic fatigue syndrome.     

中国人eNOS基因VNTR多态性的基因型与等位基因频率

一氧化氮合酶（nitric oxide synthase,NOS）催化L－精氨酸的氧化反应生成L－瓜氨酸和一氧化氮（nitric oxide,NO）。NO可通过cGMP依赖的信号传导途径介导平滑肌细胞舒张,是调节血管张力的重要信使分子。NO尚可抑制血小板凝集,对血栓形成起重要调节作用。目前在哺乳动物中已发现细胞来源、表达方式和活性调节不同的3种NOS同工酶,分别为神经元型NOS（neuronal NOS,nNOS）、诱导型NOS（inducible NOS,iNOS）和内皮细胞型NOS(endothelial NOS,eNOS）。人的eNOS基因位于第7号染色体长臂（7q36）,全长约21kb,含有26个外显子和25个内含子。eNOS基因存在多个与心脑血管疾病相关的基因多态性位点。其中位于第4内含子的一个以27bp为核心的数目可变性串联重复序列（variable number of tandem repeat,VNTR）多态性位点,已被证实与原发性高血压、心肌梗死和静脉血栓形成有关。目前在我国尚缺乏NOS基因多态性在正常人群中基因型及等位基因频率分布的统计资料。为此,我们从316名健康中国人的基因组DNA检测了eNOS基因第4内含子VNTR多态性的基因型和等位基因,鉴定出重复6次、5次和4次的3种等位基因,以及6／5杂合、5／5纯合、5／4杂合和4／4纯合的4种基因型。同时我们将正常中国人eNOS基因VNTR多态性的基因型和等位基因频率与其他种族的相关资料进行了统计对比。结果表明,中国人eNOS基因VNTR的各种基因型和等位基因频率与日本人相似,4／4纯合基因型频率与高加索人差异显著,各种基因型和等位基因频率与非裔美国人均存在显著差异。     

Circulating IgG antibodies against fungal and actinomycete antigens in the sera of farmer's lung patients from different countries

Sixty-nine farmer's lung patients and 28 normal controls from four countries (Finland, Switzerland, Canada and the United States) were investigated for antibody levels against 13 antigens commonly used for the screening panel for hypersensitivity pneumonitis. Of these antigens, eight were from the Medical College of Wisconsin (United States) and five were from the University of Kuopio (Finland). IgG antibodies against these antigens were studied in 97 sera using a sensitive biotin-avidin-linked enzyme immunoassay. The results indicate that the mean antibody titer against Micropolyspora faeni was highest in the United States (U.S.) followed by Finland. Both Finnish and U.S. antigens reacted almost identically against various groups of patients, although the degree of reactivity varied considerably. Higher antibody levels against Thermoactinomyces vulgaris were detected in Finnish patients than patients from other countries while patients from all four countries showed elevated levels of antibodies against T. candidus. This study demonstrates that antigens from identical species, irrespective of geographic origin, reacted similarly. However, variability between antigens of the same species was still considerably significant. Since the microbiological flora of moldy hay varies widely in different regions, the microbial species associated with the disease at a given geographical area has to be determined before selecting antigens for serological studies. The antigens currently used in various laboratories are crude preparations and need to be purified and standardized for dependable results. Until such antigens are available, all antigenic preparations used in the immunological evaluation of patients should be immunochemically characterized for their reproducibility and reliability although the ultimate goal should be to obtain standardized pure antigens for dependable immunodiagnosis of farmer's lung.     

Prevalence of antibody to human herpesvirus 6 in women and children

The antibody prevalence to human herpesvirus 6 (HHV-6) was compared between pregnant women and control women of similar ages in Thailand. No significant difference was detected in the antibody positive rate and antibody titers between both groups. The antibody titers in sera collected from pregnant women at 1st and 3rd trimester remained unchanged. Next, the antibody prevalence in infants were examined and the positive rate decreased until 3 months and started to increase from 6 months after birth. The present results suggest that the reactivation of HHV-6 might not occur during pregnancy and this virus infects infants postnatally.     

The ethnicity-specific association of biomarkers with the angiographic severity of coronary artery disease

Background

Risk factor burden and clinical characteristics of patients with coronary artery disease (CAD) differ among ethnic groups. We related biomarkers to CAD severity in Caucasians, Chinese, Indians and Malays.

Methods

In the Dutch-Singaporean UNICORN coronary angiography cohort (n = 2033) we compared levels of five cardiovascular biomarkers: N-terminal pro-brain natriuretic peptide (NTproBNP), high-sensitivity C-reactive protein (hsCRP), cystatin C (CysC), myeloperoxidase (MPO) and high-sensitivity troponin I (hsTnI). We assessed ethnicity-specific associations of biomarkers with CAD severity, quantified by the SYNTAX score.

Results

Adjusted for baseline differences, NTproBNP levels were significantly higher in Malays than in Chinese and Caucasians (72.1 vs. 34.4 and 41.1 pmol/l, p < 0.001 and p = 0.005, respectively). MPO levels were higher in Caucasians than in Indians (32.8 vs. 27.2 ng/ml, p = 0.026), hsTnI levels were higher in Malays than in Caucasians and Indians (33.3 vs. 16.4 and 17.8 ng/l, p < 0.001 and p = 0.029) and hsTnI levels were higher in Chinese than in Caucasians (23.3 vs. 16.4, p = 0.031). We found modifying effects of ethnicity on the association of biomarkers with SYNTAX score. NTproBNP associated more strongly with the SYNTAX score in Malays than Caucasians (β 0.132 vs. β 0.020 per 100 pmol/l increase in NTproBNP, p = 0.032). For MPO levels the association was stronger in Malays than Caucasians (β 1.146 vs. β 0.016 per 10 ng/ml increase, p = 0.017). Differing biomarker cut-off levels were found for the ethnic groups.

Conclusion

When corrected for possible confounders we observe ethnicity-specific differences in biomarker levels. Moreover, biomarkers associated differently with CAD severity, suggesting that ethnicity-specific cut-off values should be considered.     

Ethnic and Sex Variations in Dental Care Utilization Patterns in a Group of Malaysian Elderly

The purpose of this study was to identify the ethnic and sex variations in the motives for seeking dental care in a group of Malaysian elderly. Three hundred and forty-two patients aged 55 years and above who presented themselves for treatment for the first time at the Dental Faculty, University of Mayala, Kuala Lumpur in 1986 were screened for their chief dental complaints. Request for dentures and extractions and complaints of toothache were the more frequent dental motives in all the ethnic groups. However, there exist ethnic and sex variations among these dental complaints. The Chinese were found to be high utilizers of rehabilitative services whereas the Malays and Indians were more frequent utilizers of emergency services. The only consistent feature between sex among all the ethnic groups for the more frequent dental complaints was that more females complained of toothache than males.     

Continuing fertility transitions in a plural society: ethnic trends and differentials in Peninsular Malaysia

Fertility in Peninsular Malaysia has declined continuously from the late 1950s, reaching a total fertility rate of 3735 in 1983. All ethnic groups in Malaysia have contributed to this modern demographic transition but the rate of change has been most rapid for Chinese and Indians, Malay fertility having reached a plateau in the early 1980s. The effect of age structure, marital patterns and marital fertility (by parity) on the fertility declines for each ethnic community are analyzed. There has been a tendency, in each ethnic group, for the age distribution within the group of reproductive-age women to grow younger, reflecting the entry into the younger reproductive ages of the large birth cohorts of the 1950s and early 1960s. The effect of this on crude birth rates is hard to determine, because rising age at marriage and increasing use of contraception meant that fertility was increasingly concentrated in the more central reproductive ages. By the 1990s, the earlier declines in fertility will bring about a decline in the proportion of the total population made up of females in the main reproductive ages. After that point, further declines in fertility will be reflected in a sharper decline in the crude birth rate and hence the rate of population increase. Between 1947 and 1980, the age at marriage changed dramatically for females of all ethnic groups. The transition to higher age at marriage for Chinese was completed earlier, and since 1970 has risen by only a year. For Malays and Indians, the rise began later, proceeded faster and continued right up to 1980 when the medium ages at 1st marriage were Malays 22, Indians 23, Chinese 24 years. In 1980, Malay women on average were marrying 5 years later, and Indian women 6 years later than had their mothers' generation in 1947. The proportion never-married among Malay and Indian women aged 20-24 rose from 1/10 to 1/2 over this period; relatively greater changes are evident at ages 25-29. Other factors are the almost complete shift from parent-arranged to self-arranged marriages. Family size desired has decreased for all groups and the decline in breastfeeding has been offset by the sharp increase in the practice of contraception. Continuation of these trends would lead to replacement-level fertility for Malaysian Chinese and Indians by the year 2000. Malay fertility is likely to continue to decline but at a more moderate pace.     

Human herpesvirus 7: antigenic properties and prevalence in children and adults.

The recent isolation of human herpesvirus 7 (HHV-7) from activated CD4+ T lymphocytes of a healthy individual raises questions regarding the prevalence of this virus in humans and its immunological relationship to previously characterized human herpesviruses. We report that HHV-7 is a ubiquitous virus which is immunologically distinct from the highly prevalent T-lymphotropic HHV-6. Thus, (i) only two of six monoclonal antibodies to HHV-6 cross-reacted with HHV-7-infected cells, (ii) Western immunoblot analyses of viral proteins revealed different patterns for HHV-6- and HHV-7-infected cells, (iii) tests of sequential serum samples from children revealed seroconversion to HHV-6 without concomitant seroconversion to HHV-7, and (iv) in some instances HHV-7 infection occurred in the presence of high titers of HHV-6 antibodies, suggesting the lack of apparent protection of children seropositive for HHV-6 against subsequent infection with HHV-7. On the basis of the analyses of sera from children and adults it can be concluded that HHV-7 is a prevalent human herpesvirus which, like other human herpesviruses, infects during childhood. The age of infection appears to be somewhat later than the very early age documented for HHV-6.     

Prevalence of Serum Celiac Antibodies in a Multiracial Asian Population-A First Study in the Young Asian Adult Population of Malaysia

Background

Celiac disease (CD) is an immune-mediated disorder induced by the ingestion of gluten in genetically susceptible persons. The prevalence of CD in Malaysia is unknown. We aim to determine the seroprevalence of CD antibodies and also investigate the correlation between H. pylori infection and CD in the young and healthy multiracial Malaysian population.

Methods

Healthy young adult volunteers between the ages of 18–30 years were consecutively recruited from June 2012 to May 2014 at the University of Malaya Medical Centre (UMMC), Kuala Lumpur. Serum samples from all the participants were tested for anti-gliadin antibody immunoglobulin A/immunoglobulin G (IgA/IgG) and anti-tissue transglutaminase antibody (tTG) IgA/IgG. Samples positive for both anti-gliadin and anti-tTG were further validated for anti-human endomysial IgA antibodies (EmA). Serological diagnosis of CD was made when anti-gliadin, anti-tTG and anti-EmA were positive.

Results

562 qualified participants with mean age 24 ± 2.4 years old were recruited into our study. CD was found in 7 participants where most of them were asymptomatic and unaware of their CD status. The median of anti-gliadin and anti-tTG IgA/IgG value was 38.2 U/ml (interquartile range, 28.3–60.4 U/ml) and 49.2 U/ml (interquartile range, 41.1–65.9 U/ml), respectively. Seroprevalence of CD antibodies was 1.9% (6 out of 324) in female while only 0.4% (1 out of 238) in male. Seroprevalence among Malay was 0.8% (2 of 236), Chinese was 1.7% (3 of 177) and Indian was 1.3% (2 of 149). Overall, seroprevalence of CD antibodies in healthy asymptomatic adults in the Malaysian population was 1.25% (95% CI, 0.78%-1.72%). No significant relationship was discovered between CD and H. pylori infection.

Conclusions

The seroprevalence of CD antibodies in healthy young adults in the Malaysian population was 1.25% (1 in 100). CD is underdiagnosed and it could be a much greater problem in Malaysia than previously thought.     

cagA gene variants in Malaysian Helicobacter pylori strains isolated from patients of different ethnic groups

Helicobacter pylori infection of a distinct subtype of cagA may lead to different pathological manifestation. The aim of this study is to determine the presence of cagA gene and its variants in H. pylori infection among different ethnic groups and its effect on gastroduodenal diseases. Overall detection of cagA among the 205 clinical isolates of H. pylori was 94%. Variations in size of the 3' region of cagA gene were examined among 192 Malaysian H. pylori cagA-positive strains. Results showed that three cagA variants differing in fragment length of PCR products were detected and designated as type A (621-651bp), type B (732-735bp) and type C (525 bp). Although there was no association between any of the cagA subtypes with peptic ulcer disease (p>0.05), an association between cagA subtypes with a specific ethnic group was observed. Specific-cagA subtype A strains were predominantly isolated from Chinese compared to Malays and Indians (p<0.0005), and cagA subtype B strains were predominantly isolated from Malays and Indians compared to Chinese (p<0.05). The cagA type A strains of H. pylori is commonly found in the Chinese patients who have a higher risk of peptic ulcer disease, thus indicating that it could be used as an important clinical biomarker for a more severe infection.     

Induction of cell-cell fusion from without by human herpesvirus 6B

Human herpesvirus (HHV) 6A induce fusion from without (FFWO), whereas HHV-6B is believed to be ineffective in this process. Here, we demonstrate that HHV-6B induces rapid fusion in both epithelial cells and lymphocytes. The fusion was identified 1 h postinfection, could be inhibited by antibodies to HHV-6B gH and to the cellular receptor CD46, and was dependent on virus titer but independent of de novo protein synthesis and UV inactivation of the virus. Comparisons indicate that HHV-6A is only 10-fold more effective in inducing FFWO than HHV-6B. These data demonstrate that HHV-6B can induce FFWO in epithelial cells and lymphocytes.