Perinatal exposure to low doses of dioxin can permanently impair human semen quality

Background

In recent decades, young men in some industrialized areas have reportedly experienced a decrease in semen quality.

Objective

We examined effects of perinatal dioxin exposure on sperm quality and reproductive hormones.

Methods

We investigated sperm quality and hormone concentrations in 39 sons (mean age, 22.5 years) born between 1977 and 1984 to mothers exposed to dioxin after the accident in Seveso, Italy (1976), and 58 comparisons (mean age, 24.6 years) born to mothers exposed only to background dioxin. Maternal dioxin levels at conception were extrapolated from the concentrations measured in 1976 serum samples.

Results

The 21 breast-fed sons whose exposed mothers had a median serum dioxin concentration as low as 19 ppt at conception had lower sperm concentration (36.3 vs. 86.3 million/mL; p = 0.002), total count (116.9 vs. 231.1; p = 0.02), progressive motility (35.8 vs. 44.2%; p = 0.03), and total motile count (38.7 vs. 98 million; p = 0.01) than did the 36 breast-fed comparisons. The 18 formula-fed exposed and the 22 formula-fed and 36 breast-fed comparisons (maternal dioxin background 10 ppt at conception) had no sperm-related differences. Follicle-stimulating hormone was higher in the breast-fed exposed group than in the breast-fed comparisons (4.1 vs. 2.63 IU/L; p = 0.03) or the formula-fed exposed (4.1 vs. 2.6 IU/L; p = 0.04), and inhibin B was lower (breast-fed exposed group, 70.2; breast-fed comparisons, 101.8 pg/mL, p = 0.01; formula-fed exposed, 99.9 pg/mL, p = 0.02).

Conclusions

In utero and lactational exposure of children to relatively low dioxin doses can permanently reduce sperm quality.     

Complete Sequence Analysis and Antiviral Screening of Medicinal Plants for Human Coxsackievirus A16 Isolated in Korea

Objectives

Coxsackievirus A group 16 strain (CVA16) is one of the predominant causative agents of hand, foot, and mouth disease (HFMD).

Methods

Using a specimen from a male patient with HFMD, we isolated and performed sequencing of the Korean CVA16 strain and compared it with a G10 reference strain. Also, we were investigated the effects of medicinal plant extract on the cytopathic effects (CPE) by CPE reduction assay against Korean CVA16.

Results

Phylogenetic analysis showed that the Korean CVA16 isolate belonged to cluster B-1 and was closely related to the strain PM-15765-00 isolated in Malaysia in 2000. The Korean CVA16 isolate showed 73.2% nucleotide identity to the G10 prototype strain and 98.7% nucleotide identity to PM-15765-00. Next, we assessed whether the Korean CVA16 isolate could be used for in vitro screening of antiviral agents to treat HFMD infection. Vero cells infected with the Korean CVA16 isolate showed a cytopathic effect 2 days after the infection, and the treatment of cells with Cornus officinalis, Acer triflorum, Pulsatilla koreana, and Clematis heracleifolia var. davidiana Hemsl extracts exhibited strong antiviral activity against CVA16.

Conclusion

Collectively, our work provides potential candidates for the development of vaccine and novel drugs to treat the CVA16 strain isolated from a Korean patient.     

A probiotics-containing biscuit modulates the intestinal microbiota in the elderly

Objectives

Evaluation of the impact of a biscuit containing the probiotics Bifidobacterium longum Bar33 and Lactobacillus helveticus Barl3 on the intestinal microbiota in the elderly.

Design

Randomized double-blind placebo-controlled trial.

Participants

Thirty-two elderly volunteers living in Italy. The group was composed of 19 women and 13 men aged between 71 and 88 years (mean 76).

Intervention

Subjects were randomized in two groups consuming one dose of the probiotics-containing biscuit or placebo once a day for 30 days.

Measurements

For each subject the intestinal microbiota was characterized using the phylogenetic microarray platform HTF-Microbi. Array before and after intervention.

Results

Our data demonstrated that one-month consumption of a probiotics-containing biscuit was effective in redressing some of the age-related dysbioses of the intestinal microbiota. In particular, the probiotic treatment reverted the age-related increase of the opportunistic pathogens Clostridium cluster XI, Clostridium difficile, Clostridium perfringens, Enterococcus faecium and the enteropathogenic genus Campylobacter.

Conclusion

The present study opens the way to the development of elderly-tailored probiotic-based functional foods to counteract the age-related dysbioses of the intestinal microbiota.     

Protein-degradation products and bacterial enzyme activities in faeces of breast-fed and formula-fed infants

The aim of the present study was to determine the effects of age and diet (breast milk, formula milk and weaning diet) on metabolic activities in faecal samples from infants aged 1 week to 1 year, and to compare these findings with activities found in samples from adults. Such activities can provide valuable information on functional changes in the microbiota that may have significance for the health of the host. Fresh faecal samples were collected from forty-four breast-fed infants (twenty-four males, twenty females) and thirteen formula-fed infants (three males, ten females) throughout the first year of life. The samples were analysed for protein-breakdown products, including the faecal concentrations of NH3, phenol and p-cresol, and faecal bacterial enzyme activities. There was wide individual variation in all variables measured; however, the values in infants were substantially lower then those found in adults. In pre-weaned infants, faecal NH3 concentration and beta-glucuronidase activity were the only endpoints that were significantly different in breast-fed and formula-fed infants (P<0.001 and P<0.05 respectively). This was not apparent after weaning. There was a significant difference between the breast-fed and formula-fed weaned groups and their pre-weaned counterparts only for NH3 (P<0.05). beta-Glucuronidase activity and phenol concentration were significantly (P<0.01) greater in weaned breast-fed infants compared with pre-weaned breast-fed infants. No differences were observed between pre-weaned and weaned formula-fed infants for any of the variables except for NH3 concentration. It can be concluded from the present study that there are significant differences in two faecal characteristics between breast- and formula-fed infants and that changes occur as the infants grow older and are weaned onto solid foods.     

Amelioration of obesity-related characteristics by a probiotic formulation in a high-fat diet-induced obese rat model

Purpose

Obesity is a major public health concern. Despite its multi-factorial etiology, alterations in intestinal microbiota and the immune system are frequently observed. We investigated the effect of Duolac Gold (DG), a probiotic formulation containing 2 Lactobacillus strains (L. acidophilus LA1 and L. rharmnosus LR5), 3 Bifidobacterium (B. bifidum BF3, B. lactis BL3, and B. longum BG7), and Streptococcus thermophilus ST3, on morphometric and metabolic parameters, intestinal microbiota, and intestinal immune responses in a high-fat diet (HFD)-induced obese rat model.

Methods

Rats received either a conventional balanced diet or HFD with or without water containing DG for 8 weeks. HFD-induced adiposity, intestinal microbiota, and changes in inflammatory cytokine, chemokine, and metabolite levels in serum were evaluated.

Results

DG administration effectively decreased HFD-induced body weight and modulated morphometric and metabolic parameters. Quantitative analysis of fecal microbiota showed that obese rats given DG exhibited significantly increased levels of Bacteroidetes, Lactobacillus, and Bifidobacterium, with significant decreases in the level of Firmicutes. Serum levels of the inflammatory cytokines and the chemokine were also altered. Serum metabolite analysis revealed that DG administration modulated HFD-induced changes in serum metabolites, including fatty acids (FA), lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylcholine (PC), and triacylglycerol (TAG).

Conclusions

DG administration appears to have the potential to alleviate HDF-induced obesity through the modulation of intestinal microbiota, immune responses, and host metabolism, which supports the use of probiotics to treat obesity.

     

Longitudinal and Cross-Sectional Genetic Diversity in the Korean Peninsula Based on the P vivax Merozoite Surface Protein Gene

Objectives

Vivax malaria has reemerged and become endemic in Korea. Our study aimed to analyze by both longitudinal and cross-sectional genetic diversity of this malaria based on the P vivax Merozoite Surface Protein (PvMSP) gene parasites recently found in the Korean peninsula.

Methods

PvMSP-1 gene sequence analysis from P vivax isolates (n = 835) during the 1996-2010 period were longitudinally analyzed and the isolates from the Korean peninsula through South Korea, the demilitarized zone and North Korea collected in 2008-2010 were enrolled in an overall analysis of MSP-1 gene diversity.

Results

New recombinant subtypes and severe multiple-cloneinfection rates were observed in recent vivax parasites. Regional variation was also observed in the study sites.

Conclusion

This study revealed the great complexity of genetic variation and rapid dissemination of genes in P vivax. It also showed interesting patterns of diversity depending, on the region in the Korean Peninsula. Understanding the parasiteninsula. Under genetic variation may help to analyze trends and assess the extent of endemic malaria in Korea.     

Dental Care Utilization for Examination and Regional Deprivation

Objectives:

Receiving proper dental care plays a significant role in maintaining good oral health. We investigated the relationship between regional deprivation and dental care utilization.

Methods:

Multilevel logistic regression was used to identify the relationship between the regional deprivation level and dental care utilization purpose, adjusting for individual-level variables, in adults aged 19+ in the 2008 Korean Community Health Survey (n=220 258).

Results:

Among Korean adults, 12.8% used dental care to undergo examination and 21.0% visited a dentist for other reasons. In the final model, regional deprivation level was associated with significant variations in dental care utilization for examination (p<0.001). However, this relationship was not shown with dental care utilization for other reasons in the final model.

Conclusions:

This study’s findings suggest that policy interventions should be considered to reduce regional variations in rates of dental care utilization for examination.     

Neutralizing Antibody Responses and Evolution of the Viral Envelope in the Course of HIV-1 Korean Clade B Infection

Objectives

HIV is able to continuously adapt to and evade the evolving neutralizing antibody responses of the host. We investigated the ability of HIV variants to evade neutralizing antibodies in order to understand the distinct characteristics of HIV-1 Korean clade B.

Methods

Three drug-naive subjects were enrolled in this study who were infected with HIV-1 Korean clade B. Neutralizations were performed using autologous plasma and pseudovirion-based assays in order to analyze and compare changes in the env gene.

Results

In the early phase of infection, neutralizing activities against autologous virus variants gradually increased, which was followed by a decline in the humoral immune response against the subsequent viral escape variants. The amino acids lengths and number of potential N-linked glycosylation sites (PNGS) in HIV-1 env gene was positively correlated with neutralized antibody responses during the early stages of infection.

Conclusion

This study suggests that change within the env domains over the course of infection influences reactivities to neutralized antibodies and may also have an impact on host immune responses. This is the first longitudinal study of HIV-1 humoral immunity that took place over the entire course of HIV-1 Korean clade B infection.     

Prevalence of Clonorchis sinensis Infections Along the Five Major Rivers in Republic of Korea, 2007

Objectives

The prevalence of Clonorchis sinensis infection was investigated among residents of the five major river basins, that is, Hangang, Nakdonggang, Seomjingang, Yeongsangang, and Geumgang River basins in Korea.

Methods

From January to December 2007, a total of 31,268 stool samples were collected from 29 localities and examined by the formalin-ether sedimentation technique.

Results

Intestinal parasite eggs and/or protozoan cysts were detected from 2957 (9.5%) inhabitants. Number of residents harbouring helminth eggs in the faeces was 2542 (8.1%) for C. sinensis, 255 (0.8%) for Heterophyes spp., 36 (0.1%) for Echinostoma spp., 30 (0.1%) for Trichuris trichiura, 8 (0.03%) for Ascaris lumbricoides, 7 (0.02%) for Gymnophalloide seoi, and 50 (0.02%) for Trichostrongylus orientalis. Number of residents harbouring protozoan cysts in the faeces was 133 (1.3%) for Entamoeba spp. and 50 (0.2%) for Giardia lamblia. The positive rates of C. sinensis in Nakdonggang, Seomjingang, Yeongsangang, Geumgang, and Hangang River basins were 12.2%, 9.5%, 3.3%, 3.0%, and 1.0%, respectively. The egg positive rate of C. sinensis was higher in male (10.6%) than in female (6.1%), and the age group of 50s had the highest positive rate (10.4%).

Conclusion

The result of this study revealed little decrease in positive rate of C. sinensis compared with the result of southern endemic areas of Korea in 2006.Key words: Clonorchis sinensis, five major rivers, intestinal parasites, prevalence     

Impact of a Citywide Sanitation Program in Northeast Brazil on Intestinal Parasites Infection in Young Children

Background

Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households.

Objectives

We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children.

Methods

The evaluation was composed of two cross-sectional studies (1998 and 2003–2004), each of a sample of 681 and 976 children 1–4 years of age, respectively. Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site. Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions. Stool samples were examined for the presence of intestinal parasites. The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models.

Findings

The prevalence of A. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%. Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention. The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain.

Conclusion

This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population.     

Persistent Organic Pollutants Modify Gut Microbiota–Host Metabolic Homeostasis in Mice Through Aryl Hydrocarbon Receptor Activation

Background

Alteration of the gut microbiota through diet and environmental contaminants may disturb physiological homeostasis, leading to various diseases including obesity and type 2 diabetes. Because most exposure to environmentally persistent organic pollutants (POPs) occurs through the diet, the host gastrointestinal tract and commensal gut microbiota are likely to be exposed to POPs.

Objectives

We examined the effect of 2,3,7,8-tetrachlorodibenzofuran (TCDF), a persistent environmental contaminant, on gut microbiota and host metabolism, and we examined correlations between gut microbiota composition and signaling pathways.

Methods

Six-week-old male wild-type and Ahr^–/– mice on the C57BL/6J background were treated with 24 μg/kg TCDF in the diet for 5 days. We used 16S rRNA gene sequencing, ¹H nuclear magnetic resonance (NMR) metabolomics, targeted ultra-performance liquid chromatography coupled with triplequadrupole mass spectrometry, and biochemical assays to determine the microbiota compositions and the physiological and metabolic effects of TCDF.

Results

Dietary TCDF altered the gut microbiota by shifting the ratio of Firmicutes to Bacteroidetes. TCDF-treated mouse cecal contents were enriched with Butyrivibrio spp. but depleted in Oscillobacter spp. compared with vehicle-treated mice. These changes in the gut microbiota were associated with altered bile acid metabolism. Further, dietary TCDF inhibited the farnesoid X receptor (FXR) signaling pathway, triggered significant inflammation and host metabolic disorders as a result of activation of bacterial fermentation, and altered hepatic lipogenesis, gluconeogenesis, and glycogenolysis in an AHR-dependent manner.

Conclusion

These findings provide new insights into the biochemical consequences of TCDF exposure involving the alteration of the gut microbiota, modulation of nuclear receptor signaling, and disruption of host metabolism.

Citation

Zhang L, Nichols RG, Correll J, Murray IA, Tanaka N, Smith PB, Hubbard TD, Sebastian A, Albert I, Hatzakis E, Gonzalez FJ, Perdew GH, Patterson AD. 2015. Persistent organic pollutants modify gut microbiota–host metabolic homeostasis in mice through aryl hydrocarbon receptor activation. Environ Health Perspect 123:679–688; http://dx.doi.org/10.1289/ehp.1409055     

Cloning and Expression of Recombinant Tick-Borne Encephalitis Virus-like Particles in Pichia pastoris

Objectives

The purpose of this study was to verify the feasibility of using the glyceraldehyde-3-phosphate dehydrogenase (GAP) promotor based Pichia pastoris expression system to produce tick-borne encephalitis virus (TBEV) virus-like particles (VLPs).

Methods

The complementary DNA encoding the TBEV prM signal peptide, prM, and E proteins of TBEV Korean strain (KrM 93) was cloned into the plasmid vector pGAPZɑA, then integrated into the genome of P. pastoris, under the control of the GAP promoter. Expression of TBEV VLPs was determined by Western blotting using monoclonal antibody against TBEV envelope (E) protein.

Results

Recombinant TBEV VLPs consisting of prM and E protein were successfully expressed using the GAP promoter-based P. pastoris expression system. The results of Western blotting showed that the recombinant proteins were secreted into the culture supernatant from the P. pastoris and glycosylated.

Conclusion

This study suggests that recombinant TBEV VLPs from P. pastoris offer a promising approach to the production of VLPs for use as vaccines and diagnostic antigens.     

Determinants of Poor Self-rated Health in Korean Adults With Diabetes

Objectives:

Self-rated health is a measure of perceived health widely used in epidemiological studies. Our study investigated the determinants of poor self-rated health in middle-aged Korean adults with diabetes.

Methods:

A cross-sectional study was conducted based on the Health Examinees Study. A total of 9759 adults aged 40 to 69 years who reported having physician-diagnosed diabetes were analyzed with regard to a range of health determinants, including sociodemographic, lifestyle, psychosocial, and physical variables, in association with self-rated health status using multivariate logistic regression models. A p-value <0.05 was considered to indicate statistical significance.

Results:

We found that negative psychosocial conditions, including frequent stress events and severe distress according to the psychosocial well-being index, were most strongly associated with poor self-rated health (odds ratio [OR]_{Frequent stress events}, 5.40; 95% confidence interval [CI], 4.63 to 6.29; OR_{Severe distress}, 11.08; 95% CI, 8.77 to 14.00). Moreover, younger age and being underweight or obese were shown to be associated with poor self-rated health. Physical factors relating to participants’ medical history of diabetes, such as a younger age at diagnosis, a longer duration of diabetes, insulin therapy, hemoglobin A_1clevels of 6.5% or more, and comorbidities, were other correlates of poor reported health.

Conclusions:

Our findings suggest that, in addition to medical variables, unfavorable socioeconomic factors, and adverse lifestyle behaviors, younger age, being underweight or obese, and psychosocial stress could be distinc factors in predicting negative perceived health status in Korean adults with diabetes.     

Mid-upper arm circumference at age of routine infant vaccination to identify infants at elevated risk of death: a retrospective cohort study in the Gambia

Objective

To determine the predictive value for death before 12 months of age of mid-upper arm circumference (MUAC) and weight-for-length Z score (WFLz).

Methods

A retrospective cohort analysis of infants living in Keneba, in rural Gambia, was conducted. Anthropometric measures were obtained from demographic surveillance system records for infants registered between February 1974 and July 2008 who had had MUAC and WFLz recorded at 6–14 weeks of age and vital status recorded at least once more. Hazard ratios (HRs), population attributable fractions and areas under receiver operating characteristic (ROC) curves were estimated to assess the predictive value for death in infancy of MUAC and WFLz.

Findings

Of 2876 infants included in the analysis, 40 died before the age of 12 months. The HR for death in this group versus in well-nourished infants was 5.8 (95% confidence interval, CI: 1.6–21) for a WFLz < −3. HRs for MUACs below the thresholds of 115 mm, 110 mm and 105 mm were 4.5 (95% CI: 1.4–15), 9.5 (95% CI: 2.6–35) and 23 (95% CI: 4.2–122), respectively. The attributable fractions for a MUAC < 130 mm and a WFLz < 0 were 51% and 13%, respectively. The areas under the ROC curve for death in infancy were 0.55 (95% CI: 0.46 to 0.64) for WFLz and 0.64 (95% CI: 0.55 to 0.73) for MUAC.

Conclusion

Among infants aged 6 to 14 weeks, unadjusted MUAC showed good performance in identifying infants at increased risk of death.     

Trends in Water- and Foodborne Disease Outbreaks in Korea, 2007–2009

Objectives

In Korea, every outbreak of acute gastroenteritis in two or more patients who are epidemiologically related is investigated by local public health centres to determine causative agents and control the outbreak with the support of the Korean Centers for Disease Control and Prevention. The findings and conclusions of each outbreak investigation have been summarized annually since 2007 to make reports and statistics of water- and foodborne disease outbreaks.

Methods

All outbreaks reported to Korean Centers for Disease Control and Prevention from 2007 to 2009 were included in the study. We analysed the trends and epidemiologic aspects of outbreaks by month, year, and location.

Results

The total number of outbreaks decreased steadily each year for the period the study covered, whereas the number of patients per outbreak continued to increase resulting from a dramatic increase in the number of patients per outbreak in food service establishments. The outbreaks occurred in the period of June to September, when temperature and humidity are relatively high, which accounted for 44.3% of total outbreaks. The monthly number of outbreaks decreased steadily until November after peaking in May 2009. The most common causative agent was norovirus (16.5%) followed by pathogenic Escherichia coli. The rate of causative agent identification was 60.1%, with higher identification rates in larger outbreaks.

Conclusions

Although a decreasing trend of outbreaks by year was observed in the study, the food services in schools and companies require more attention to hygiene and sanitation to prevent large outbreaks. The ability to establish the cause of an outbreak should be further improved.Key words: Escherichia coli, foodborne diseases, Korea, norovirus     

Intake of Soy Products and Other Foods and Gastric Cancer Risk: A Prospective Study

Background

Gastric cancer, the most common cancer in the world, is affected by some foods or food groups. We examined the relationship between dietary intake and stomach cancer risk in the Korean Multi-Center Cancer Cohort (KMCC).

Methods

The KMCC included 19 688 Korean men and women who were enrolled from 1993 to 2004. Of those subjects, 9724 completed a brief 14-food frequency questionnaire at baseline. Through record linkage with the Korean Central Cancer Registry and National Death Certificate databases, we documented 166 gastric cancer cases as of December 31, 2008. Cox proportional hazard models were used to estimate relative risks (RRs) and 95% CIs.

Results

Frequent intake of soybean/tofu was significantly associated with reduced risk of gastric cancer, after adjustment for age, sex, cigarette smoking, body mass index, alcohol consumption, and area of residence (P for trend = 0.036). We found a significant inverse association between soybean/tofu intake and gastric cancer risk among women (RR = 0.41, 95% CI: 0.22–0.78). Men with a high soybean/tofu intake had a lower risk of gastric cancer, but the reduction was not statistically significant (RR = 0.77, 95% CI: 0.52–1.13). There was no interaction between soybean/tofu intake and cigarette smoking in relation to gastric cancer risk (P for interaction = 0.268).

Conclusions

Frequent soybean/tofu intake was associated with lower risk of gastric cancer.Key words: soybean, dietary intake, gastric cancer     

Relationship between adhering to dietary guidelines and the risk of obesity in Korean children

BACKGROUND/OBJECTIVES

Dietary guidelines for Korean children were released in 2009. The goal of the present study was to examine diet quality in terms of adherence to these dietary guidelines as well as explore the association between guideline adherence and risk of obesity in Korean children.

SUBJECTS/METHODS

Children aged 5-11 years (mean age = 8.9 years old, n = 191, 80.6% girls) were recruited from a university hospital in Seoul, Korea. Adherence to dietary guidelines for Korean children was calculated using the Likert scale (1-5), and children were then categorized into low, moderate, and high groups based on adherence scores. Obesity or being overweight was determined based on an age- and gender- specific percentile for body mass index (BMI) of the 2007 Korean National Growth Charts. Diet quality was evaluated from 3 days of dietary intake data.

RESULTS

Children in the high adherence group were characterized by significantly lower BMI percentiles and paternal BMIs as well as higher percentages of fathers with a high level of education and higher household incomes compared to those in the low or moderate group. Children in the high adherence group consumed significantly higher amounts of milk and dairy products, were less likely to consume lower than the EAR of phosphorus and iron, and had higher NARs for calcium, phosphorus, iron, zinc, and MAR than those in low groups. The ORs for obesity (BMI ≥ 95^th percentile) or being overweight including obesity (BMI ≥ 85^th percentile) were significantly lower in the high adherence group compared to the low adherence group (OR: 0.33, 95% CI = 0.13-0.82, P for trend = 0.019; OR: 0.26, 95% CI: 0.11-0.61 P for trend = 0.002).

CONCLUSIONS

Korean children who adhered to dietary guidelines displayed better diet quality and a reduced risk of obesity.