The impact of adolescent pertussis immunization, 2004-2009: lessons from Australia

Objective

To compare the impact of three strategies for delivering a booster dose of adult-formulated tetanus–diphtheria–pertussis (Tdap) vaccine to adolescents in Australia. These comprise: (i) administering Tdap to: a one-year age cohort; (ii) administering Tdap to the entire high school and to subsequent entrant cohorts; and (iii) administering Tdap to the entire high school but without continuing to immunize entrant cohorts.

Methods

A series of ecologic analyses of pertussis notifications during epidemic periods in relevant age cohorts were conducted. The primary outcome measure was the incidence rate ratio (IRR), calculated by dividing pertussis incidence after the introduction of Tdap delivery programmes by pertussis incidence during the most recent pre-programme epidemic.

Findings

During the epidemic period of 2008–2009, the national-level IRR among age cohorts targeted for Tdap was 0.6 (95% confidence interval, CI: 0.6–0.7), but among other age cohorts it was 1.1 (95% CI: 1.1–1.2). Only the jurisdiction that implemented strategy 2 (Western Australia) experienced sustained decreases in pertussis notifications in both adolescents and infants under 6 months of age (IRR: 0.4; 95% CI: 0.3–0.6) until 2009.

Conclusion

If confirmed by longer experience in Australia and elsewhere, a broad school-based catch-up programme followed by immunization of school entrants may be the optimum strategy for the implementation of adolescent Tdap programmes.     

Arsenic speciation analysis of urine samples from individuals living in an arsenic-contaminated area in Bangladesh

Objectives

Chronic inorganic arsenic (iAs) exposure currently affects tens of millions of people worldwide. To accurately determine the proportion of urinary arsenic metabolites in residents continuously exposed to iAs, we performed arsenic speciation analysis of the urine of these individuals and determined whether a correlation exists between the concentration of iAs in drinking water and the urinary arsenic species content.

Methods

The subjects were 165 married couples who had lived in the Pabna District in Bangladesh for more than 5 years. Arsenic species were measured using high-performance liquid chromatography and inductively coupled plasma mass spectrometry.

Results

The median iAs concentration in drinking water was 55 μgAs/L (range <0.5–332 μgAs/L). Speciation analysis revealed the presence of arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid in urine samples with medians (range) of 16.8 (7.7–32.3), 1.8 (<0.5–3.3), 13.7 (5.6–25.0), and 88.6 μgAs/L (47.9–153.4 μgAs/L), respectively. No arsenobetaine or arsenocholine was detected. The concentrations of the 4 urinary arsenic species were significantly and linearly related to each other. The urinary concentrations of total arsenic and each species were significantly correlated with the iAs concentration of drinking water.

Conclusions

All urinary arsenic species are well correlated with each other and with iAs in drinking water. The most significant linear relationship existed between the iAs concentration in drinking water and urinary iAs + MMA concentration. From these results, combined with the effects of seafood ingestion, the best biomarker of iAs exposure is urinary iAs + MMA concentration.     

A revised method for determination of dialkylphosphate levels in human urine by solid-phase extraction and liquid chromatography with tandem mass spectrometry: application to human urine samples from Japanese children

Objectives

Biological monitoring of organophosphorus insecticide (OP) metabolites, specifically dialkylphosphates (DAP) in urine, plays a key role in low-level exposure assessment of OP in individuals. The aims of this study are to develop a simple and sensitive method for determining four urinary DAPs using high-performance liquid chromatography with tandem mass spectrometry (LC–MS/MS), and to assess the concentration range of urinary DAP in Japanese children.

Methods

Deuterium-labeled DAPs were used as internal standards. Urinary dimethylphosphate (DMP) and diethylphosphate (DEP), which passed through the solid-phase extraction (SPE) column, and dimethylthiophosphate (DMTP) and diethylthiophosphate (DETP), which were extracted from a SPE column using 2.5 % NH₃ water including 50 % acetonitrile, were prepared for separation analysis. The samples were then injected into LC–MS/MS. The optimized method was applied to spot urine samples from 3-year-old children (109 males and 116 females) living in Aichi Prefecture in Japan.

Results

Results from the validation study demonstrated good within- and between-run precisions (<10.7 %) with low detection limits (0.4 for DMP and DMTP, 0.2 for DEP and 0.1 μg/L for DETP). The geometric mean values and detection rates of the urinary DAPs in Japanese children were 14.4 μg/L and 100 % for DMP, 5.3 μg/L and 98 % for DMTP, 5.5 μg/L and 99 % for DEP, and 0.6 μg/L and 80 % for DETP, respectively.

Conclusions

The present high-throughput method is simple and reliable, and can thereby further contribute to development of an exposure assessment of OP. The present study is the first to reveal the DAP concentrations in young Japanese children.     

Chlorpyrifos exposure and biological monitoring among manufacturing workers

Aim

To use biological monitoring data to evaluate the soundness of job based exposure classifications.

Methods

The authors studied 52 chlorpyrifos manufacturing workers and 60 referent workers to compare chlorpyrifos exposure estimations from job titles and work areas to urinary excretion of 3,5,6 trichloro‐2‐pyridinol (TCP), a metabolite of chlorpyrifos. Work history records and industrial hygiene monitoring data were used to establish cumulative interim exposure. Chlorpyrifos exposure during the study year was assessed biologically by urinary excretion of TCP.

Results

Exposure as measured by three urinary TCP samples was significantly higher among the chlorpyrifos workers (188 μg/l) than it was for the referent subjects (7 μg/l). Urinary TCP also correlated well with specific exposure categories of negligible (0.73–1.98 mg/m³ days), low (1.99–4.91 mg/m³ days), and moderate (4.92–15.36 mg/m³ days). The weighted Kappa coefficient was 0.80 (95% CI 0.72 to 0.87) for the mean TCP over the study period.

Conclusions

The estimates of chlorpyrifos exposure based on job classifications and industrial hygiene measurements were significantly related to urinary TCP excretion, indicating that the ambient estimates are useful for providing exposure estimates among chlorpyrifos manufacturing workers.     

Food intake survey of kindergarten children in Korea: Part 3 cadmium and lead burden

Objectives

This study was initiated to elucidate the extent of dietary exposure of children in Korea to two pollutant metals of cadmium (Cd) and lead (Pb). Possible urban–rural difference was also examined.

Methods

Food duplicate and morning spot urine samples were collected from 108 children in 4 kindergartens (KG) (1 KG in Seoul and 3 KGs in Jeju Island), as reported in a previous publication. The samples were analyzed for Cd and Pb by ICP-MS.

Results

Cd and Pb in food duplicate and urine samples were distributed approximately log-normally. Geometric means for Cd and Pb in food duplicate samples were 12.4 and 5.8 μg/day, or 0.58 and 0.27 μg/kg body weight/day, respectively, and the values for Cd and Pb in urine (as observed, i.e., with no correction for urine density) were 0.91 and 1.64 μg/L, respectively. 2.41 and 0.30 μg/day of Cd and Pb (accounting for 19.5 and 5.1 %) came from boiled rice, the staple food. The levels of Cd and Pb burden among the children in the present survey were essentially the same with the levels reported for children in Pusan. The reasons for difference in the rank in Cd-D and Cd-U among the 4 KGs need further study.

Conclusions

The observed levels of Cd and Pb exposure were more or less similar to what were reported for children in Pusan. No apparent urban–rural difference could be detected.     

Effect of vitamin?A supplementation on cause-specific mortality in women of reproductive age in Ghana: a secondary analysis from the ObaapaVitA trial

Objective

To determine the effect of weekly low-dose vitamin A supplementation on cause-specific mortality in women of reproductive age in Ghana.

Methods

A cluster-randomized, triple-blind, placebo-controlled trial was conducted in seven districts of the Brong Ahafo region of Ghana. Women aged 15–45 years who were capable of giving informed consent and intended to live in the trial area for at least 3 months were enrolled and randomly assigned, according to their cluster of residence, to receive oral vitamin A (7500 μg) or placebo once a week. Randomization was blocked, with two clusters in each fieldwork area allocated to vitamin A and two to placebo. Every 4 weeks, fieldworkers distributed capsules and collected data during home visits. Verbal autopsies were conducted by field supervisors and reviewed by physicians, who assigned a cause of death. Cause-specific mortality rates in both arms were compared by means of random-effects Poisson regression models to allow for the cluster randomization. Analysis was by intention-to-treat, based on cluster of residence, with women eligible for inclusion once they had consistently received the supplement or placebo capsules for 6 months.

Findings

The analysis was based on 581 870 woman–years and 2624 deaths. Cause-specific mortality rates were found to be similar in the two study arms.

Conclusion

Low-dose vitamin A supplements administered weekly are of no benefit in programmes to reduce mortality in women of childbearing age.     

Biomarkers of chlorpyrifos exposure and effect in Egyptian cotton field workers

Background

Chlorpyrifos (CPF), a widely used organophosphorus pesticide (OP), is metabolized to CPF-oxon, a potent cholinesterase (ChE) inhibitor, and trichloro-2-pyridinol (TCPy). Urinary TCPy is often used as a biomarker for CPF exposure, whereas blood ChE activity is considered an indicator of CPF toxicity. However, whether these biomarkers are dose related has not been studied extensively in populations with repeated daily OP exposures.

Objective

We sought to determine the relationship between blood ChE and urinary TCPy during repeated occupational exposures to CPF.

Methods

Daily urine samples and weekly blood samples were collected from pesticide workers (n = 38) in Menoufia Governorate, Egypt, before, during, and after 9–17 consecutive days of CPF application to cotton fields. We compared blood butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) activities with the respective urinary TCPy concentrations in each worker.

Results

Average TCPy levels during the middle of a 1- to 2-week CPF application period were significantly higher in pesticide applicators (6,437 μg/g creatinine) than in technicians (184 μg/g) and engineers (157 μg/g), both of whom are involved in supervising the application process. We observed a statistically significant inverse correlation between urinary TCPy and blood BuChE and AChE activities. The no-effect level (or inflection point) of the exposure–effect relationships has an average urinary TCPy level of 114 μg/g creatinine for BuChE and 3,161 μg/g creatinine for AChE.

Conclusions

Our findings demonstrate a dose–effect relationship between urinary TCPy and both plasma BuChE and red blood cell AChE in humans exposed occupationally to CPF. These findings will contribute to future risk assessment efforts for CPF exposure.     

Population-based inorganic mercury biomonitoring and the identification of skin care products as a source of exposure in New York City

Background

Mercury is a toxic metal that has been used for centuries as a constituent of medicines and other items.

Objective

We assessed exposure to inorganic mercury in the adult population of New York City (NYC).

Methods

We measured mercury concentrations in spot urine specimens from a representative sample of 1,840 adult New Yorkers in the 2004 NYC Health and Nutrition Examination Survey. Cases with urine concentrations ≥ 20 μg/L were followed up with a telephone or in-person interview that asked about potential sources of exposure, including ritualistic/cultural practices, skin care products, mercury spills, herbal medicine products, and fish.

Results

Geometric mean urine mercury concentration in NYC was higher for Caribbean-born blacks [1.39 μg/L; 95% confidence interval (CI), 1.14–1.70] and Dominicans (1.04 μg/L; 95% CI, 0.82–1.33) than for non-Hispanic whites (0.67 μg/L; 95% CI, 0.60–0.75) or other racial/ethnic groups. It was also higher among those who reported at least 20 fish meals in the past 30 days (1.02 μg/L; 95% CI, 0.83–1.25) than among those who reported no fish meals (0.50 μg/L; 95% CI, 0.41–0.61). We observed the highest 95th percentile of exposure (21.18 μg/L; 95% CI, 7.25–51.29) among Dominican women. Mercury-containing skin-lightening creams were a source of exposure among those most highly exposed, and we subsequently identified 12 imported products containing illegal levels of mercury in NYC stores.

Conclusion

Population-based biomonitoring identified a previously unrecognized source of exposure to inorganic mercury among NYC residents. In response, the NYC Health Department embargoed products and notified store owners and the public that skin-lightening creams and other skin care products that contain mercury are dangerous and illegal. Although exposure to inorganic mercury is not a widespread problem in NYC, users of these products may be at risk of health effects from exposure.     

Food intake survey of kindergarten children in Korea: Part 2 increased dietary intake of tin possibly associated with canned foods

Objectives

Dietary intake of tin (Sn) may be increased in some children in kindergartens in Korea. The present study was intended to examine this possibility and clarify the extent of the elevation.

Methods

24-hour food duplicate and spot urine samples were collected in 2003–2004 from 108 4–6-year-old children (boys and girls combined) in 4 kindergartens (1 in Seoul and 3 in Jeju Island), as reported in a previous publication. These samples were employed in the present analyses to examine tin levels in the diet (including beverages) (Sn-D). A portion of the samples were wet-ashed, and the liquid samples were analyzed for Sn by the ICP-MS method. For statistical evaluation, χ² method and Smirnov’s test for extreme value were used.

Results

Sn-D in the 108 cases distributed as extremely biased, and could be divided into two groups, i.e., those with <10 μg Sn/day (accounting for 90 % of the cases), and those with >10 μg/day (for 10 %). Sn-D in the former group was distributed quasi-normally with an AM (median) of 2.9 (2.5) μg/day. The maximum in the latter group was 3012 μg/day. No correlation was detected between Sn-D and Sn in urine (Sn-U). Comparison of the findings with published articles strongly suggested that the high Sn-D was due to consumption of foods (including beverages) preserved in tin-plated cans. No positive confirmation was however possible due to insufficient information on food records.

Conclusions

About 10 % of children surveyed had elevated Sn-D (up to 3 mg/day). It was quite possible that high Sn-D was associated with tin-canned food intake.     

Frequent exposure to suboptimal temperatures in vaccine cold-chain system in India: results of temperature monitoring in 10 states

Objective

To estimate the proportion of time the vaccines in the cold-chain system in India are exposed to temperatures of < 0 or > 8 °C.

Methods

In each of 10 states, the largest district and the one most distant from the state capital were selected for study. Four boxes, each containing an electronic temperature recorder and two vials of diphtheria, pertussis and tetanus vaccine, were placed in the state or regional vaccine store for each study state. Two of these boxes were then shipped – one per facility – towards the two most peripheral health facilities where vaccine was stored in each study district. The boxes were shipped, handled and stored as if they were routine vaccine supplies.

Findings

In state, regional and district vaccine stores and peripheral health facilities, respectively, the temperatures in the boxes exceeded 8 °C for 14.3%, 13.2%, 8.3% and 14.7% of their combined storage times and fell below 0 °C for 1.5%, 0.2%, 0.6% and 10.5% of these times. The boxes also spent about 18% and 7% of their combined times in transit at < 0 and > 8 °C, respectively. In shake tests conducted at the end of the study, two thirds of the vaccine vials in the boxes showed evidence of freezing.

Conclusion

While exposure to temperatures above 8 °C occurred at every level of vaccine storage, exposure to subzero temperatures was only frequent during vaccine storage at peripheral facilities and vaccine transportation. Systematic efforts are needed to improve temperature monitoring in the cold-chain system in India.     

Improved HPLC Method Using 2,3-naphthalenedicarboxaldehyde as Fluorescent Labeling Agent for Quantification of Histamine in Human Immunoglobulin Preparations

Objectives

To develop and optimize quantitative HPLC method using 2,3-naphthalenedicarboxaldehyde (NDA) after simple and efficient solid phase extraction to determine the histamine in a biopharmaceutical (Histobulin™).

Methods

The HPLC method was established using NDA-induced Histobulin and compared with the recently reported HPLC method using o-phthaldehyde (OPA). The validated NDA-applied HPLC method was adjusted to 15 lots of Histobulin and compared by the current lot-release-test method using fluorimetry in recovery of histamine and reproducibility.

Results

Analyses of six HPLC chromatograms using NDA and OPA each were compared. NDA produced a more stable chromatogram baseline than OPA, and showed better stability. The HPLC analysis was validated in accuracy (91–103%), precision (interday/intraday assay CV ≤2.30%), and linearity of dose–response curve (R² ≥ 0.9919). The detection limit was 0.0076 μg/mL and the quantitative limit was 0.0229 μg/mL. The amount of histamine per 12 mg of immunoglobulin was determined to be 0.17 ± 0.016 μg by the HPLC and 0.025 ± 0.013 μg by the current lot-release-test method using fluorimetry.

Conclusion

NDA derivatization showed better stability compared with the OPA method. Therefore the newly established NDA-derivatizated HPLC method may be more suitable than the fluorimetric method in lot-release-tests of biopharmaceuticals.     

Case-control study of blood lead levels and attention deficit hyperactivity disorder in Chinese children

Background

Attention deficit/hyperactivity disorder (ADHD) and lead exposure are high-prevalence conditions among children.

Objective

Our goal was to investigate the association between ADHD and blood lead levels (BLLs) in Chinese children, adjusting for known ADHD risk factors and potential confounding variables.

Methods

We conducted a pair-matching case–control study with 630 ADHD cases and 630 non-ADHD controls 4–12 years of age, matched on the same age, sex, and socioeconomic status. The case and control children were systematically evaluated via structured diagnostic interviews, including caregiver interviews, based on the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., revised criteria (DSM-IV-R). We evaluated the association between BLLs and ADHD using the Pearson chi-square test for categorical variables and the Student t-test for continuous data. We then performed conditional multiple variables logistic regression analyses with backward stepwise selection to predict risk factors for ADHD.

Results

There was a significant difference in BLLs between ADHD cases and controls. ADHD cases were more likely to have been exposed to lead during childhood than the non-ADHD control subjects, with adjustment for other known risk factors [children with BLLs ≥ 10 μg/dL vs. ≤ 5 μg/dL; OR = 6.0; 95% confidence interval (CI) = 4.10–8.77, p < 0.01; 5–10 μg/dL vs.≤ 5 μg/dL, OR = 4.9; 95% CI = 3.47–6.98, p < 0.01]. These results were not modified by age and sex variables.

Conclusions

This was the largest sample size case–control study to date to study the association between BLLs and ADHD in Chinese children. ADHD may be an additional deleterious outcome of lead exposure during childhood, even when BLLs are < 10 μg/dL.     

Biomonitoring of mercury,cadmium, and lead exposure in Japanese children: a cross-sectional study

Objectives

To measure current Hg, Cd, and Pb exposure in Japanese children, and to estimate dietary intakes of foods responsible for high body burden.

Methods

Blood, hair, and urine samples were collected from 9 to 10-year-old 229 children in Asahikawa and measured for Hg, Cd, and Pb in these matrices. Diet history questionnaire was used to estimate intake of marine foods and other food items. Hg level was measured by cold vapor atomic absorption spectrometry. Cd and Pb levels were determined with inductively coupled plasma mass spectrometry.

Results

Geometric mean (GM) of blood Hg, Cd, and Pb was 4.55 μg/L, 0.34 μg/L, and 0.96 μg/dL, respectively. Urinary Cd level was 0.34 μg/g creatinine (GM) and hair Hg was 1.31 μg/g (GM). Approximately one-third (35 %) of blood samples had Hg level above the U.S. EPA reference dose (RfD; 5.8 μg/L). Hair Hg level exceeded U.S. EPA RfD (1.2 μg/g) in 59 % samples. Children in the upper quartile of blood Hg level had significantly higher intake of large predatory fish species compared to those in the lower quartile of blood Hg.

Conclusions

Those with high blood Hg level may be explained by more frequent intake of big predatory fish. Cd and Pb exposure is generally low among Japanese children. As no safety margin exists for Pb exposure and high exposure to MeHg is noted in Japanese population; periodic biomonitoring and potential health risk assessment should continue in high-risk populations, notably among children.     

Urinary cadmium and osteoporosis in U.S. Women >or= 50 years of age: NHANES 1988-1994 and 1999-2004

Background

Urinary cadmium (U-Cd) has been associated with decreased peripheral bone mineral density (BMD) and osteoporosis. This association, however, has not been confirmed using femoral BMD, the international standard for diagnosing osteoporosis, at levels < 1.0 μg Cd/g creatinine.

Objectives

Our goal was to investigate the statistical association between U-Cd, at levels ≤ 1 μg/g creatinine, and osteoporosis, as indicated by hip BMD and self-report in a population-based sample of U.S. women ≥ 50 years of age.

Methods

We drew data from the National Health and Nutrition Examination Surveys for 1988–1994 (n = 3,207) and 1999–2004 (n = 1,051). Osteoporosis was indicated by hip BMD cutoffs based on the international standard and self-report of physician diagnosis. We analyzed U-Cd levels for association with osteoporosis using multiple logistic regression.

Results

Women ≥ 50 years of age with U-Cd levels between 0.50 and 1.00 μg/g creatinine were at 43% greater risk for hip-BMD–defined osteoporosis, relative to those with levels ≤ 0.50 μg/g (odds ratio = 1.43; 95% confidence interval, 1.02–2.00; p = 0.04). We observed similar effect estimates using self-report of physician-diagnosed osteoporosis. Smokers did not show a statistically increased risk.

Conclusions

Results suggest that U.S. women are at risk for osteoporosis at U-Cd levels below the U.S. Occupational Safety and Health Administration’s 3-μg/g safety standard. Given null findings among smokers, dietary Cd, rather than tobacco, is the likely source of Cd-related osteoporosis risk for the U.S. female population ≥ 50 years of age.     

Viet Nam��s mandatory motorcycle helmet law and its impact on children

Objective

To measure the use of motorcycle helmets in children and to determine the reasons why children wear helmets less often than adults.

Methods

The frequency of helmet wearing among adults and children was ascertained by trained roadside observers, and randomized road user surveys were completed in four major centres in Viet Nam: Hanoi, Ho Chi Minh City, Can Tho and Da Nang. Survey data on key questions were cross tabulated, and χ² was calculated for significant differences between parents and non-parents (0.05).

Findings

The frequency of helmet use in the four study locations ranged from 90–99% among adults, from 15–53% among children ≤ 7 years of age, and from 38–53% among children > 7 but ≤ 14. Of the parents surveyed, 67% said the fear of neck injury was the most important reason their children did not wear a helmet.

Conclusion

Children wear motorcycle helmets much less often than adults. Legislation to penalize adults whose children do not wear motorcycle helmets has been proposed in Viet Nam. Furthermore, ongoing advocacy and social marketing efforts are being made to disseminate information about the safety benefits of helmets to combat erroneous public perceptions.     

Low-level lead exposure and elevations in blood pressure during pregnancy

Background

Lead exposure is associated with elevated blood pressure during pregnancy; however, the magnitude of this relationship at low exposure levels is unclear.

Objectives

Our goal was to determine the association between low-level lead exposure and blood pressure during late pregnancy.

Methods

We collected admission and maximum (based on systolic) blood pressures during labor and delivery among 285 women in Baltimore, Maryland. We measured umbilical cord blood lead using inductively coupled plasma mass spectrometry. Multivariable models were adjusted for age, race, median household income, parity, smoking during pregnancy, prepregnancy body mass index, and anemia. These models were used to calculate benchmark dose values.

Results

Geometric mean cord blood lead was 0.66 μg/dL (95% confidence interval, 0.61–0.70). Comparing blood pressure measurements between those in the highest and those in the lowest quartile of lead exposure, we observed a 6.87-mmHg (1.51–12.21 mmHg) increase in admission systolic blood pressure and a 4.40-mmHg (0.21–8.59 mmHg) increase in admission diastolic blood pressure after adjustment for confounders. Corresponding values for maximum blood pressure increase were 7.72 (1.83–13.60) and 8.33 (1.14–15.53) mmHg. Benchmark dose lower limit values for a 1-SD increase in blood pressure were < 2 μg/dL blood lead for all blood pressure end points.

Conclusions

A significant association between low-level lead exposures and elevations in maternal blood pressure during labor and delivery can be observed at umbilical blood lead levels < 2 μg/dL.     

Chronic hepatitis C treatment outcomes in low- and middle-income countries: a systematic review and meta-analysis

Objective

To assess the effectiveness of treatment for hepatitis C virus (HCV) infection in low- and middle-income countries and identify factors associated with successful outcomes.

Methods

We performed a systematic review and meta-analysis of studies of HCV treatment programmes in low- and middle-income countries. The primary outcome was a sustained virological response (SVR). Factors associated with treatment outcomes were identified by random-effects meta-regression analysis.

Findings

The analysis involved data on 12 213 patients included in 93 studies from 17 countries. The overall SVR rate was 52% (95% confidence interval, CI: 48–56). For studies in which patients were predominantly infected with genotype 1 or 4 HCV, the pooled SVR rate was 49% (95% CI: 43–55). This was significantly lower than the rate of 59% (95% CI: 54–64) found in studies in which patients were predominantly infected with other genotypes (P = 0.012). Factors associated with successful outcomes included treatment with pegylated interferon and ribavirin, infection with an HCV genotype other than genotype 1 or 4 and the absence of liver damage or human immunodeficiency virus infection at baseline. No significant difference in the SVR rate was observed between weight-adjusted and fixed-dose ribavirin treatment. Overall, 17% (95% CI: 13–23) of adverse events resulted in treatment interruption or dose modification, but only 4% (95% CI: 3–5) resulted in treatment discontinuation.

Conclusion

The outcomes of treatment for HCV infection in low- and middle-income countries were similar to those reported in high-income countries.     

Survival analysis of long-term exposure to different sizes of airborne particulate matter and risk of infant mortality using a birth cohort in Seoul, Korea

Background

Several studies suggest that airborne particulate matter (PM) is associated with infant mortality; however, most focused on short-term exposure to larger particles.

Objectives

We evaluated associations between long-term exposure to different sizes of particles [total suspended particles (TSP), PM ≤ 10 μm in aerodynamic diameter (PM₁₀), ≤ 10–2.5 μm (PM_10–2.5), and ≤ 2.5 μm (PM_2.5)] and infant mortality in a cohort in Seoul, Korea, 2004–2007.

Methods

The study includes 359,459 births with 225 deaths. We applied extended Cox proportional hazards modeling with time-dependent covariates to three mortality categories: all causes, respiratory, and sudden infant death syndrome (SIDS). We calculated exposures from birth to death (or end of eligibility for outcome at 1 year of age) and pregnancy (gestation and each trimester) and treated exposures as time-dependent variables for subjects’ exposure for each pollutant. We adjusted by sex, gestational length, season of birth, maternal age and educational level, and heat index. Each cause of death and exposure time frame was analyzed separately.

Results

We found a relationship between gestational exposures to PM and infant mortality from all causes or respiratory causes for normal-birth-weight infants. For total mortality (all causes), risks were 1.44 (95% confidence interval, 1.06–1.97), 1.65 (1.18–2.31), 1.53 (1.22–1.90), and 1.19 (0.83–1.70) per interquartile range increase in TSP, PM₁₀, PM_2.5, and PM_10–2.5, respectively; for respiratory mortality, risks were 3.78 (1.18–12.13), 6.20 (1.50–25.66), 3.15 (1.26–7.85), and 2.86 (0.76–10.85). For SIDS, risks were 0.92 (0.33–2.58), 1.15 (0.38–3.48), 1.42 (0.71–2.87), and 0.57 (0.16–1.96), respectively.

Conclusions

Our findings provide supportive evidence of an association of long-term exposure to PM air pollution with infant mortality.     

Age-related effects of fasting on ketone body production during lipolysis in rats

Objective

The age-related effects of fasting on lipolysis, the production of ketone bodies, and plasma insulin levels were studied in male 3-, 8-, and 32-week-old Sprague–Dawley rats.

Methods

The rats were divided into fasting and control groups. The 3-, 8- and 32-week-old rats tolerated fasting for 2, 5, and 12 days, respectively.

Results

Fasting markedly reduced the weights of perirenal and periepididymal white adipose tissues in rats in the three age groups. The mean rates of reduction in both these adipose tissue weights during fasting periods were higher in the order of 3 > 8 > 32-week-old rats. Fasting transiently increased plasma free fatty acid (FFA), total ketone body, β-hydroxybutyrate, and acetoacetate concentrations in the rats in the three age groups. However, plasma FFA, total ketone body, β-hydroxybutyrate, and acetoacetate concentrations in the 3-week-old rats reached maximal peak within 2 days after the onset of fasting, although these concentrations in the 8- and 32-week-old rats took more than 2 days to reach the maximal peak. By contrast, the augmentation of plasma FFA, total ketone body, β-hydroxybutyrate, and acetoacetate concentrations in the rats in the three age groups had declined at the end of each experimental period. Thus, the capacity for fat mobilization was associated with tolerance to fasting. Plasma insulin concentrations in the rats in the three age groups were dramatically reduced during fasting periods, although basal levels of insulin were higher in the order of 32 > 8 > 3 week-old rats.

Conclusion

These results suggest that differences in fat metabolism patterns among rats in the three age groups during prolonged fasting were partly reflected the metabolic turnover rates, plasma insulin levels, and amounts of fat storage.     

Effect of laughter on salivary flow rates and levels of chromogranin A in young adults and elderly people

Objectives

Salivary chromogranin A (CgA) levels and salivary flow rates were measured to evaluate the stress relief effect of laughter on the young and the elderly.

Methods

Thirty healthy volunteers (15 aged 20–25 years; 15 aged 62–83 years) performed a serial arithmetic task for 15 min and then watched a comedy video for 30 min. On a different day, as a control, they watched a non-humorous video after performing a task similar to the first one. Saliva samples were collected immediately before and after the arithmetic task, 30 min after completing the task (immediately after watching the film), and 30 min after watching the film (60 min after completing mental task). Salivary CgA levels were determined by enzyme-linked immunosorbent assay.

Results

In the elderly group, salivary flow rates, which had declined by the end of the arithmetic task, were statistically significantly higher after watching the comedy video. In the young group, salivary CgA levels, which had increased by the end of the task, had statistically significantly declined after watching the comedy video. No such post-task changes were apparent in control results; in the young group, there was a statistically significant interprotocol difference in salivary CgA levels.

Conclusions

These findings suggest that laughter may relieve stress, particularly in the young people.