Blood Lead Levels and Cause-Specific Mortality of Inorganic Lead-Exposed Workers in South Korea

The objective of this study was to identify the association of blood lead level (BLL) with mortality in inorganic lead-exposed workers of South Korea. A cohort was compiled comprising 81,067 inorganic lead exposed workers working between January 1, 2000, and December 31, 2004. This cohort was merged with the Korean National Statistical Office to follow-up for mortality between 2000 and 2008. After adjusting for age and other carcinogenic metal exposure, all-cause mortality (Relative risk [RR] 1.36, 95% confidence interval [CI] 1.03–1.79), digestive disease (RR 3.23, 95% CI 1.33–7.86), and intentional self-harm (RR 2.92, 95% CI 1.07–7.81) were statistically significantly higher in males with BLL >20 μg/dl than of those with BLL ≤10μg/dl. The RR of males with BLL of 10–20 μg/dl was statistically higher than of those with BLL ≤10μg/dl in infection (RR 3.73. 95% CI, 1.06–13.06). The RRs of females with 10–20 μg/dl BLL was statistically significantly greater than those with BLL <10μg/dl in all-cause mortality (RR 1.93, 95% CI 1.16–3.20) and colon and rectal cancer (RR 13.42, 95% CI 1.21–149.4). The RRs of females with BLL 10–20 μg/dl (RR 10.45, 95% CI 1.74–62.93) and BLL ≥20 μg/dl (RR 12.68, 95% CI 1.69–147.86) was statistically significantly increased in bronchus and lung cancer. The increased suicide of males with ≥20 μg/dl BLLs, which might be caused by major depression, might be associated with higher lead exposure. Also, increased bronchus and lung cancer mortality in female workers with higher BLL might be related to lead exposure considering low smoking rate in females. The kinds of BLL-associated mortality differed by gender.     

Hair Mercury Concentrations of Lactating Mothers and Breastfed Infants in Iran (Fish Consumption and Mercury Exposure)

Coastal populations with high seafood consumption in the South Caspian Sea (Iran) have a significant exposure to dietary mercury. This study assesses the biomonitoring of mercury in mothers and breastfed infants in the South Caspian Sea. The mean of mercury concentration in the hair of 93 pairs of mothers and infants was obtained and was 3.55 and 1.89???g?g^?1, respectively. A statistically significant correlation (R?=?0.850, P?=?0.000) was seen between mercury concentration in the hair of mothers and infants. The results of this study indicate that hair mercury concentrations exceeded the USEPA reference dose of 1???g?g^?1 in 82.7?% of mothers and 61.2?% of infants. Also, 31?% of the mothers and 10.7?% of the infants had mercury concentrations more than the WHO ??threshold?? level (5???g?g^?1). The age and fish consumption of mothers were the factors that significantly affected the hair mercury concentration of mothers and infants. Number of dental amalgam fillings of mothers was the factor that only affected mercury in the hair of mothers. According to the results, we can conclude that the main determinant of mercury exposure was the intake of mercury through fish consumption of mothers.     

Direct somatic embryogenesis from leaf and petiole explants of Spathiphyllum ‘Supreme’ and analysis of regenerants using flow cytometry

This study established a method of regenerating Spathiphyllum ??Supreme?? through direct somatic embryogenesis. Somatic embryos occurred in leaf and petiole explants cultured in the dark on a Murashige and Skoog basal medium supplemented with 2.27, 4.54, or 9.08???M N-phenyl-N??-1,2,3-thiadiazol-5-ylurea (TDZ) in combination with 1.08???M ??-naphthalene acetic acid or 2.26???M 2,4-dichlorophenoxyacetic acid (2,4-D). Explants with somatic embryos were transferred to fresh medium containing the same concentrations of growth regulators under lighted conditions for embryo conversion. The highest frequencies of leaf explants with somatic embryos and embryo conversion were both 84.4?%, which were induced by 9.08???M TDZ with 2.26???M 2,4-D. The frequencies for somatic embryo induction and embryo conversion were both 100?% when petiole explants were induced by 4.54???M TDZ with 2.26???M 2,4-D. The number of plantlets produced per leaf explant and petiole explant were as high as 67.4 and 74.4, respectively. Plantlets after transplanting to a soilless substrate grew vigorously in a shaded greenhouse. Liners were stable without phenotypic variation. Flow cytometry analysis of randomly selected plants showed that they all had a single identical peak. The mean nuclear DNA index for ??Supreme?? was 1.568, and the nuclear DNA content was 14.222?pg 2C^?1. The estimated genome size for ??Supreme?? was 6,954.5?Mbp 1C^?1 with a CV at 4.008?%. The results suggest that the regenerated plants have a stable ploidy level and this established regeneration method can be used for highly effective propagation of uniform Spathiphyllum ??Supreme??.     

Postnatal Environmental Tobacco Smoke Exposure Related to Behavioral Problems in Children

ObjectiveThe purpose of this study was to examine the association between pre and post environmental tobacco smoke (ETS) exposure and behavioral problems in schoolchildren.MethodsIn the cross-sectional 6 cities Study conducted in France, 5221 primary school children were investigated. Pre- and postnatal exposure to secondhand tobacco smoke at home was assessed using a parent questionnaire. Child’s behavioral outcomes (emotional symptoms and conduct problems) were evaluated by the Strengths and Difficulties Questionnaire (SDQ) completed by the parents.ResultsETS exposure during the postnatal period and during both pre- and postnatal periods was associated with behavioral problems in children. Abnormal emotional symptoms (internalizing problems) were related to ETS exposure in children who were exposed during the pre- and postnatal periods with an OR of 1.72 (95% Confidence Interval (CI)= 1.36-2.17), whereas the OR was estimated to be 1.38 (95% CI= 1.12-1.69) in the case of postnatal exposure only. Abnormal conduct problems (externalizing problems) were related to ETS exposure in children who were exposed during the pre- and postnatal periods with an OR of 1.94 (95% CI= 1.51-2.50), whereas the OR was estimated to be 1.47 (95% CI=1.17-1.84) in the case of postnatal exposure only. Effect estimates were adjusted for gender, study center, ethnic origin, child age, low parental education, current physician diagnosed asthma, siblings, preterm birth and single parenthood.ConclusionPostnatal ETS exposure, alone or in association with prenatal exposure, increases the risk of behavioral problems in school-age children.     

Ploidy level stability of adventitious shoots of sour cherry ‘?a?anski Rubin’ and Gisela 5 cherry rootstock

The capacity of regeneration of adventitious shoots from leaf explants was studied in sour cherry ???a?anski Rubin?? (Prunus cerasus L.) and cherry rootstock Gisela 5 (P. cerasus?×?P. canescens). Regeneration assay included thirty different combinations of plant growth regulators. 6-benzyladenine (BA) and thidiazuron (TDZ) were applied either individually or each combined with different concentrations of indole-3-butyric acid, ??-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). ???a?anski Rubin?? showed higher regeneration capacity in comparison with Gisela 5 regarding the total number of treatments inducing regeneration as well as the highest frequency of regeneration achieved. In both genotypes, 8.9???M BA was more effective than both 4.5 and 9.0???M TDZ in inducing adventitious regeneration, but only when combined with auxins. The highest frequency of regeneration (20.8?%) in ???a?anski Rubin?? was achieved on medium supplemented with 8.9???M BA combined with 5.4???M NAA, while in Gisela 5 the highest value (8.3?%) was obtained when BA was combined with 4.5???M 2,4-D. Flow cytometry combined with 4??-6-diamidino-2-phenylindole staining was employed to estimate DNA ploidy levels and relative nuclear DNA content in adventitious regeneration-derived shoots, in vitro shoots of axillary origin and in vivo control plants from open field. No significant differences in nuclear DNA content were detected among plants of different origin. Chromosome counting in root tip meristems also showed normal tetraploid chromosome number (2n?=?4x?=?32) in ???a?anski Rubin?? shoots and normal triploid chromosome number (2n?=?3x?=?24) in Gisela 5 shoots regenerated in vitro. The results obtained suggest that no major genetic instability occurred during adventitious regeneration under the described experimental conditions.     

‘Only Fathers Smoking’ Contributes the Most to Socioeconomic Inequalities: Changes in Socioeconomic Inequalities in Infants’ Exposure to Second Hand Smoke over Time in Japan

BackgroundExposure to second hand smoke (SHS) is one of the major causes of premature death and disease among children. While socioeconomic inequalities exist for adult smoking, such evidence is limited for SHS exposure in children. Thus, this study examined changes over time in socioeconomic inequalities in infants’ SHS exposure in Japan.MethodsThis is a repeated cross-sectional study of 41,833 infants born in 2001 and 32,120 infants born in 2010 in Japan from nationally representative surveys using questionnaires. The prevalence of infants’ SHS exposure was determined and related to household income and parental education level. The magnitudes of income and educational inequalities in infants’ SHS exposure were estimated in 2001 and 2010 using both absolute and relative inequality indices.ResultsThe prevalence of SHS exposure in infants declined from 2001 to 2010. The relative index of inequality increased from 0.85 (95% confidence interval [CI], 0.80 to 0.89) to 1.47 (95% CI, 1.37 to 1.56) based on income and from 1.22 (95% CI, 1.17 to 1.26) to 2.09 (95% CI, 2.00 to 2.17) based on education. In contrast, the slope index of inequality decreased from 30.9 (95% CI, 29.3 to 32.6) to 20.1 (95% CI, 18.7 to 21.5) based on income and from 44.6 (95% CI, 43.1 to 46.2) to 28.7 (95% CI, 27.3 to 30.0) based on education. Having only a father who smoked indoors was a major contributor to absolute income inequality in infants’ SHS exposure in 2010, which increased in importance from 45.1% in 2001 to 67.0% in 2010.ConclusionsThe socioeconomic inequalities in infants’ second hand smoke exposure increased in relative terms but decreased in absolute terms from 2001 to 2010. Further efforts are needed to encourage parents to quit smoking and protect infants from second hand smoke exposure, especially in low socioeconomic households that include non-smoking mothers.     

Comparative Study of Blood Lead Levels in Uruguayan Children (1994–2004)

Lead does not fulfill any physiological function in the human body. It is generally accepted that the blood lead level (BLL) is the best exposure index, as there is an excellent correlation between the actual exposure of the individual and the concentration of lead in blood. In Uruguay, lead contamination becomes a matter of public concern in 2001, giving rise to a sensitization in the population, which in many cases brought about a change in hygienic and dietary habits of the children. In 2004, after the leaded gasoline phasing out process in Uruguay was completed, we studied non-exposed children to correlate BLL with variables such as age, sex, area of residence, and available environmental lead data and compared these results with those from our similar screening studies 10years ago. The main result of this comparison is that BLL from children in our country had a significant decrease between 1994 and 2004.     

Callus induction and shoot organogenesis from anther cultures of Curcuma attenuata Wall

Curcuma attenuata is a highly valued ornamental. This study provides the first report on C. attenuata shoot organogenesis and plant regeneration. Immature anthers derived from 5 to 7?cm long inflorescences were isolated and cultured on different variations of Murashige and Skoog (MS) media to induce callus and then shoot organogenesis. When the 2-mm long anthers in which microspores were at the uninucleate developmental stage were cultured in the dark on MS medium containing 13.6???M 2,4-dichlorophenoxyacetic acid (2,4-D) and 2.3???M kinetin (KT) for 15?days and then transferred to 40???mol?m^?2?s^?1 fluorescent light for 30?days, the percentage callus induction reached 33.3?%. After callus was transferred to various differentiation media and cultured in the light, 33.1?% of all callus cultures could differentiate into adventitious shoots on MS medium supplemented with 22.0???M 6-benzyladenine (BA), 0.53???M ??-naphthaleneacetic acid (NAA) and 1.4???M thidiazuron (TDZ) after culturing for 60?days. Over 95?% of plantlets survived after transplanting plantlets into trays with a mixture of sand and perlite (2: 1) for 20?days. Chromosome number, determined from the root tips of young plantlets, indicated that all plantlets were diploid (2n?=?84).     

Is the Association Between Helicobacter pylori Infection and Anemia Age Dependent?

Background: The relationship between H. pylori infection and anemia in childhood is still unclear. The aim of the study was to examine the association between H. pylori infection and anemia or iron deficiency in school‐age children and in infants. Materials and Methods: Six‐ to 9‐ year‐old Israeli Arab children (N = 202) and infants (N = 197) were examined for hemoglobin and ferritin levels. ELISA was used to detect H. pylori antigens in stool specimens collected from the participants. Household characteristics were obtained through personal interviews with the mothers. Results: The prevalence of anemia was 15.5 versus 5.5% in H. pylori‐positive and ‐negative school‐age children, respectively and 34.5 versus 29.8% in H. pylori‐positive and ‐negative infants, respectively. The Mantel–Haenszel age‐adjusted prevalence ratio (PR) and 95% confidence intervals (CIs) were 1.6 (95%CI 1.0, 2.6). In multivariate analysis controlling for socioeconomic variables, H. pylori infection was associated with 2.8 higher prevalence of anemia only in school‐age children: adjusted PR 2.8 (95% CI 0.9, 9.3). The adjusted mean difference in hemoglobin levels between H. pylori infected school‐age children and uninfected ones was ?0.372 gr/dL (95% CI ?0.704, ?0.039) (p = .04). The respective mean ferritin difference was ?6.74 μg/L (95% CI ?13.38, ?.011) (p = .04). Such differences were not found in infants. Conclusions: H. pylori infection is associated with higher prevalence of anemia in school‐age children independently of socioeconomic variables. Such association was not observed in infants. These findings are of clinical and public health importance.     

Efficiency of direct and indirect shoot organogenesis in different genotypes of Rosa hybrida

To optimize indirect regeneration (IR) and direct regeneration (DR) in Rosa hybrida cv. Apollo different explant types and different concentrations of plant growth regulators were investigated. Among the different auxins studied and over all explant types, 10???M 2,4-dichlorophenoxyacetic acid (2,4-D) promoted the highest frequency of callus production for IR. The highest frequency of regeneration (60.8?%) was obtained when calli were transferred to Murashige and Skoog medium supplemented with 2.5???M thidiazuron (TDZ) and 2???M gibberellic acid. The highest frequency of regeneration (80.2?%) for DR was obtained from leaves cultured on the medium containing 10???M TDZ. The efficiency of IR and DR were compared in four different rose cultivars including ??Apollo??, ??Black Baccara??, ??Maroussia?? and ??Amanda??. The frequency of regeneration in all four cultivars was significantly higher in DR compared to IR. Also shoots regenerated by DR appeared earlier than the shoots regenerated by IR. The results of flow cytometry showed that the shoots derived from IR to DR were tetraploid like the original cultivars.     

Exposure of thermoelectric power-plant workers to volatile organic compounds from fuel oil: genotoxic and cytotoxic effects in buccal epithelial cells

Thermoelectric power-plant workers are constantly exposed to high levels of potentially genotoxic gaseous substances, such as volatile organic compounds (VOCs) from the combustion of fuel oil or the processing of naphtha. The aim of the present study was to estimate the association between such occupational exposure and the frequency of micronucleated cells and cells with other nuclear anomalies. Buccal epithelial cells were collected from a total of 44 power-plant workers (exposed group) and 47 administrative workers (non-exposed group), and examined for the frequency of micronucleated cells (MNC) and of cells with other nuclear anomalies (ONA: pyknosis, karyolysis, and karyorrhexis) by means of the micronucleus assay. The frequencies of MNC and ONA per 1000 cells in the exposed group (1.8‰ and 82.4‰, respectively) were significantly higher than in the non-exposed group (0.2‰ and 58.3‰, respectively). The exposed group had a twelve-fold increase in risk for formation of MNC compared with non-exposed individuals (RR=12.1; 95% CI, 5.0-29.2; P<0.001). The confounding factors analyzed (age, smoking status, alcohol consumption, and mouthwash use) did not show any significant association with the frequency of MNC or ONA. The findings of this study show that workers from power plants exposed to VOCs have a significantly elevated risk for DNA damage. Therefore, bio-monitoring of DNA damage is recommended for this group of workers.     

Socioeconomic inequalities in prevalence and development of multimorbidity across adulthood: A longitudinal analysis of the MRC 1946 National Survey of Health and Development in the UK

BackgroundWe aimed to estimate multimorbidity trajectories and quantify socioeconomic inequalities based on childhood and adulthood socioeconomic position (SEP) in the risks and rates of multimorbidity accumulation across adulthood.Methods and findingsParticipants from the UK 1946 National Survey of Health and Development (NSHD) birth cohort study who attended the age 36 years assessment in 1982 and any one of the follow-up assessments at ages 43, 53, 63, and 69 years (N = 3,723, 51% males). Information on 18 health conditions was based on a combination of self-report, biomarkers, health records, and prescribed medications. We estimated multimorbidity trajectories and delineated socioeconomic inequalities (based on childhood and adulthood social class and highest education) in multimorbidity at each age and in longitudinal trajectories.Multimorbidity increased with age (0.7 conditions at 36 years to 3.7 at 69 years). Multimorbidity accumulation was nonlinear, accelerating with age at the rate of 0.08 conditions/year (95% CI 0.07 to 0.09, p < 0.001) at 36 to 43 years to 0.19 conditions/year (95% CI 0.18 to 0.20, p < 0.001) at 63 to 69 years. At all ages, the most socioeconomically disadvantaged had 1.2 to 1.4 times greater number of conditions on average compared to the most advantaged. The most disadvantaged by each socioeconomic indicator experienced an additional 0.39 conditions (childhood social class), 0.83 (adult social class), and 1.08 conditions (adult education) at age 69 years, independent of all other socioeconomic indicators. Adverse adulthood SEP was associated with more rapid accumulation of multimorbidity, resulting in 0.49 excess conditions in partly/unskilled compared to professional/intermediate individuals between 63 and 69 years. Disadvantaged childhood social class, independently of adulthood SEP, was associated with accelerated multimorbidity trajectories from age 53 years onwards.Study limitations include that the NSHD cohort is composed of individuals of white European heritage only, and findings may not be generalizable to the non-white British population of the same generation and did not account for other important dimensions of SEP such as income and wealth.ConclusionsIn this study, we found that socioeconomically disadvantaged individuals have earlier onset and more rapid accumulation of multimorbidity resulting in widening inequalities into old age, with independent contributions from both childhood and adulthood SEP.

Amal Khanolkar and co-workers study associations between multimorbidity and socioeconomic position in the UK.     

Interannual fluctuations in copepod abundance and contribution of small forms in the Drake Passage during austral summer

The relative importance of small forms of copepods has been historically underestimated by the traditional use of 200?C300-??m mesh nets. This work quantified the distribution and abundance of copepods, considering two size fractions (<300???m and >300???m), in superficial waters (9?m deep) of the Drake Passage and contributed to the knowledge of their interannual fluctuations among three summers. Four types of nauplii and eleven species of copepods at copepodite and adult stages were identified, with abundance values of up to 13 ind L^?1 and 28,300???g C m^?3. The <300-??m fraction, composed of Oithona similis, small cyclopoids and nauplii, dominated the copepod communities in the 3?years; it accounted for more than 77% of the total number and for between 40 and 63% of the total biomass. Changes in density and biomass values among the three cruises differed according to copepod size fraction and water mass; the >300-??m fraction showed no changes among the 3?years, both in Antarctic (density and biomass) and in Subantarctic waters (density), whereas the <300-??m fraction showed higher (density and biomass) values in 2001 both in Subantarctic and in Antarctic waters. Sea surface temperature and its anomaly accounted for the largest proportion of variability in copepod density and biomass, particularly for the <300-??m fraction.     

A genetic linkage map of an apple rootstock progeny anchored to the Malus genome sequence

An apple rootstock progeny raised from the cross between the very dwarfing ??M.27?? and the more vigorous ??M.116?? (??M.M.106???×???M.27??) was used for the construction of a linkage map comprising a total of 324 loci: 252 previously mapped SSRs, 71 newly characterised or previously unmapped SSR loci (including 36 amplified by 33 out of the 35 novel markers reported here), and the self-incompatibility locus. The map spanned the 17 linkage groups (LG) expected for apple covering a genetic distance of 1,229.5?cM, an estimated 91% of the Malus genome. Linkage groups were well populated and, although marker density ranged from 2.3 to 6.2?cM/SSR, just 15 gaps of more than 15?cM were observed. Moreover, only 17.5% of markers displayed segregation distortion and, unsurprisingly in a semi-compatible backcross, distortion was particularly pronounced surrounding the self-incompatibility locus (S) at the bottom of LG17. DNA sequences of 273 SSR markers and the S locus, representing a total of 314 loci in this investigation, were used to anchor to the ??Golden Delicious?? genome sequence. More than 260 of these loci were located on the expected pseudo-chromosome on the ??Golden Delicious?? genome or on its homeologous pseudo-chromosome. In total, 282.4?Mbp of sequence from 142 genome sequence scaffolds of the Malus genome were anchored to the ??M.27???×???M.116?? map, providing an interface between the marker data and the underlying genome sequence. This will be exploited for the identification of genes responsible for traits of agronomic importance such as dwarfing and water use efficiency.     

Obstetric Outcomes of Mothers Previously Exposed to Sexual Violence

Background

There is a scarcity of data on the association of sexual violence and women''s subsequent obstetric outcomes. Our aim was to investigate whether women exposed to sexual violence as teenagers (12–19 years of age) or adults present with different obstetric outcomes than women with no record of such violence.

Methods

We linked detailed prospectively collected information on women attending a Rape Trauma Service (RTS) to the Icelandic Medical Birth Registry (IBR). Women who attended the RTS in 1993–2010 and delivered (on average 5.8 years later) at least one singleton infant in Iceland through 2012 formed our exposed cohort (n = 1068). For each exposed woman''s delivery, nine deliveries by women with no RTS attendance were randomly selected from the IBR (n = 9126) matched on age, parity, and year and season of delivery. Information on smoking and Body mass index (BMI) was available for a sub-sample (n = 792 exposed and n = 1416 non-exposed women). Poisson regression models were used to estimate Relative Risks (RR) with 95% confidence intervals (CI).

Results

Compared with non-exposed women, exposed women presented with increased risks of maternal distress during labor and delivery (RR 1.68, 95% CI 1.01–2.79), prolonged first stage of labor (RR 1.40, 95% CI 1.03–1.88), antepartum bleeding (RR 1.95, 95% CI 1.22–3.07) and emergency instrumental delivery (RR 1.16, 95% CI 1.00–1.34). Slightly higher risks were seen for women assaulted as teenagers. Overall, we did not observe differences between the groups regarding the risk of elective cesarean section (RR 0.86, 95% CI 0.61–1.21), except for a reduced risk among those assaulted as teenagers (RR 0.56, 95% CI 0.34–0.93). Adjusting for maternal smoking and BMI in a sub-sample did not substantially affect point estimates.

Conclusion

Our prospective data suggest that women with a history of sexual assault, particularly as teenagers, are at increased risks of some adverse obstetric outcomes.     

GIS-facilitated in vitro propagation and ex situ conservation of Achillea occulta

A Geographical Information Systems (GIS)-facilitated approach for the in vitro propagation and ex situ conservation of the conservation priority species Achillea occulta is presented. To realize the species?? ecological requirements, the coordinates of the original habitat were linked with thematic layers derived from digital databases in a GIS environment. From wild plants, shoot tips were established in vitro in a basal medium with 4???M 6-benzyladenine (BA) and 0.5???M indole-3-butyric acid (IBA). A modified basal MS medium (modMS, double amount of Fe) proved to be the most effective for in vitro adventitious shoot production. The effect of BA in combination with ??-naphthaleneacetic acid (NAA) or IBA on shoot proliferation was also tested. The highest number of new microshoots/explant (3.5), with 0.93?cm shoot height was obtained when the modMS was supplemented with 5???M BA and 2.5???M IBA. To evaluate the root induction ability, microshoots produced were transferred to modMS media supplemented with 0?C20???M IBA and 0?C20???M NAA. Rooting proved to be very difficult and only by adding 20???M IBA, a 12.5% rooting percentage was achieved. Acclimatization succeeded only during early spring. Young plants transplanted at the Balkan Botanic Garden of Kroussia produced flowers and seeds in the first year. This GIS-approach provided useful guidelines for A. occulta??s (a) effective propagation (selection of greenhouse temperatures, temperatures during in vitro culture, suitable period for cuttings and acclimatization of plantlets), and (b) ex situ cultivation (selection of watering regime, temperatures, locations and exposures for growing sites).     

The Effects of Cobalt on the Development, Oxidative Stress, and Apoptosis in Zebrafish Embryos

Metal-on-metal hip arthroplasty has been performed with increasing frequency throughout the world, particularly in younger and more active patients, including women of childbearing age. The potential toxicity of cobalt exposure on fetus is concerned since cobalt ions generated by metal-on-metal bearings can traverse the placenta and be detected in fetal blood and amniotic fluid. This study examined the effects of cobalt exposure on early embryonic development and the mechanisms underlying its toxicity. Zebrafish embryos were exposed to a range of cobalt concentrations (0?C100?mg/L) between 1 and 144?h postfertilization. The survival and early development of embryos were not significantly affected by cobalt at concentrations <100???g/L. However, embryos exposed to higher concentrations (>100???g/L) displayed reduced survival rates and abnormal development, including delayed hatching, aberrant morphology, retarded growth, and bradycardia. Furthermore, this study examined oxidative stress and apoptosis in embryos exposed to cobalt at concentrations of 0?C500???g/L. Lipid peroxidation levels were increased in cobalt-treated embryos at concentrations of 100 and 500???g/L. The mRNA levels of catalase, superoxide dismutase 2, p53, caspase-3, and caspase-9 genes were upregulated in a dose-dependent manner. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays also revealed abnormal apoptotic signals in the brain, trunk, and tail when treated with 500???g/L cobalt. These data suggest that oxidative stress and apoptosis are associated with cobalt toxicity in zebrafish embryos.     

The association between household socioeconomic position and prevalent tuberculosis in Zambia: a case-control study

Background

Although historically tuberculosis (TB) has been associated with poverty, few analytical studies from developing countries have tried to: 1. assess the relative impact of poverty on TB after the emergence of HIV; 2. explore the causal mechanism underlying this association; and 3. estimate how many cases of TB could be prevented by improving household socioeconomic position (SEP).

Methods and Findings

We undertook a case-control study nested within a population-based TB and HIV prevalence survey conducted in 2005–2006 in two Zambian communities. Cases were defined as persons (15+ years of age) culture positive for M. tuberculosis. Controls were randomly drawn from the TB-free participants enrolled in the prevalence survey. We developed a composite index of household SEP combining variables accounting for four different domains of household SEP. The analysis of the mediation pathway between household SEP and TB was driven by a pre-defined conceptual framework. Adjusted Population Attributable Fractions (aPAF) were estimated.Prevalent TB was significantly associated with lower household SEP [aOR = 6.2, 95%CI: 2.0–19.2 and aOR = 3.4, 95%CI: 1.8–7.6 respectively for low and medium household SEP compared to high]. Other risk factors for prevalent TB included having a diet poor in proteins [aOR = 3.1, 95%CI: 1.1–8.7], being HIV positive [aOR = 3.1, 95%CI: 1.7–5.8], not BCG vaccinated [aOR = 7.7, 95%CI: 2.8–20.8], and having a history of migration [aOR = 5.2, 95%CI: 2.7–10.2]. These associations were not confounded by household SEP. The association between household SEP and TB appeared to be mediated by inadequate consumption of protein food. Approximately the same proportion of cases could be attributed to this variable and HIV infection (aPAF = 42% and 36%, respectively).

Conclusions

While the fight against HIV remains central for TB control, interventions addressing low household SEP and, especially food availability, may contribute to strengthen our control efforts.     

Nanoinjection: pronuclear DNA delivery using a charged lance

We present a non-fluidic pronuclear injection method using a silicon microchip ??nanoinjector?? composed of a microelectromechanical system with a solid, electrically conductive lance. Unlike microinjection which uses fluid delivery of DNA, nanoinjection electrically accumulates DNA on the lance, the DNA-coated lance is inserted into the pronucleus, and DNA is electrically released. We compared nanoinjection and microinjection side-by-side over the course of 4?days, injecting 1,013 eggs between the two groups. Nanoinjected zygotes had significantly higher rates of integration per injected embryo, with 6.2?% integration for nanoinjected embryos compared to 1.6?% integration for microinjected embryos. This advantage is explained by nanoinjected zygotes?? significantly higher viability in two stages of development: zygote progress to two-cell stage, and progress from two-cell stage embryos to birth. We observed that 77.6?% of nanoinjected zygotes proceeded to two-cell stage compared to 54.7?% of microinjected zygotes. Of the healthy two-cell stage embryos, 52.4?% from the nanoinjection group and 23.9?% from the microinjected group developed into pups. Structural advantages of the nanoinjector are likely to contribute to the high viability observed. For instance, because charge is used to retain and release DNA, extracellular fluid is not injected into the pronucleus and the cross-sectional area of the nanoinjection lance (0.06???m²) is smaller than that of a microinjection pipette tip (0.78???m²). According to results from the comparative nanoinjection versus microinjection study, we conclude that nanoinjection is a viable method of pronuclear DNA transfer which presents viability advantages over microinjection.     

Adventitious shoot regeneration in cotyledons from Japanese pear and related species

An efficient method for the generation of adventitious shoots from the cotyledons of Japanese pear and related species was developed. Cotyledons from seeds of the Japanese pear ??Okusankichi?? and the Asian pea pear ??Hokushimamenashi?? were used to determine the optimum concentrations of phytohormones in the medium. The rates of generation of adventitious shoots and the numbers of adventitious shoots per explant were highest when the media contained 5???M 1-naphthaleneacetic acid combined with 10 or 25???M 6-benzylaminopurine. These growth regulators were used to generate adventitious shoots from the cotyledons of 33 cultivars of Japanese, Chinese, Asian pea, and European pears. A high number of adventitious shoots per explant (1.3?C2.3) and high rates of regeneration of adventitious shoots (60?C76?%) were obtained from the cotyledons of Japanese pears ??Imamuraaki?? and ??Agenosho Shinanashi.?? Although pollination was not controlled, cotyledons from mother trees of old Japanese cultivars and Chinese pears tended to be more regenerable than those from other pear species. Since the rooting ability of the adventitious shoots was very low, micro-grafting was applied to obtain regenerated potted plants from adventitious shoots. Grafted regenerated plants were recovered at a rate of more than 60?%, regardless of cultivar. To our knowledge, this is the first report to evaluate shoot regeneration from cotyledons of major Pyrus species.