Causal association between kynurenine and depression investigated using two-sample mendelian randomization

As research progresses, the intricate metabolic connections between depression and tryptophan, as well as kynurenine (KYN), have become increasingly evident. In studies investigating the relationship between KYN and depression, the conclusions reached thus far have been inconsistent. Therefore, we propose employing a two-sample mendelian randomization (MR) approach to further elucidate the relationship between KYN and depression. We utilized extensive data from large-scale genome-wide association studies to identify single nucleotide polymorphisms that act as instrumental variables for kynurenine and depression in European ancestry populations, ensuring compliance with MR assumptions. We employed five MR algorithms, namely, weighted median, MR-Egger, inverse variance weighted (IVW), simple mode, and weighted mode, with IVW as the primary analysis method. Sensitivity tests were conducted using Cochran's Q test, MR-Egger intercept test, MR Pleiotropy Residual Sum and Outlier, and Leave-one-out analysis.The IVW analysis revealed that each standard deviation increase in kynurenine corresponded to a 1.4-fold increase in the risk of depression (OR = 1.351, 95% CI 1.110-1.645, P = 0.003). The direction of the effect size (positive or negative) was consistent with the findings from the other four algorithms. Sensitivity tests indicated no heterogeneity or horizontal pleiotropy among the instrumental variables. Elevated levels of kynurenine have a causal relationship with an increased risk of developing depression.

[Epidemiological characteristics and survival analysis of reported pneumoconiosis in Chengdu, 2012-2021]

Objective: To explore theepidemiological characteristics and analyse the survival of pneumoconiosis in Chengdu from 2011 to 2021, providing scientific evidence for further prevention and control. Methods: In April 2022, the pneumoconiosis report card of Chengdu from 2012 to 2021 and survival data were collected from the China Disease Control and prevention information system and the occupational pneumoconiosis follow-up survey project.The data of the report card was reorganized and analyzed by R4.4.0 software. Chi-square test was used to compare the case composition ratio between groups. The annual trend of the number of new pneumo coniosis cases was analyzed by linear regression model Kaplan-Meier method was used for survival analysis and log-rank test was used for comparison of survival curves between groups. Results: 816 cases of pneumoconiosis were reported in Chengdu from 2011 to 2021, including 522 cases of stage Ⅰ (63.97%, 522/816), 148 cases of stage Ⅱ (18.14%, 148/816) and 146 cases of stage Ⅲ pneumoconiosis (17.89146/816) ; There were 596 cases of silicosis (73.04%, 596/816), 143 cases of coal worker's pneumoconiosis (17.52%, 143/816). New onset pneumoconiosis was mainly male (810 cases, 99.26%). The median age of diagnosis and the 25th and 75th percentile were 63 (51-71) years old, the median length of dust exposure were 12.00 (5.92-28.00) years, and the types of work were mainly rock drillers (24.63%, 201/816), tunneling workers (19.36%, 158/816) and coal miners (13.60%, 111/816). Among 816 cases of new pneumoconiosis, 35 cases were lost to follow-up (4.29%, 35/816), 605 cases survived and 176 cases died. The 5-year survival rate was 78.6% and the 10-year survival rate was 65.8%. Conclusion: The number of pneumoconiosis reported in Chengdu was relatively stable in recent years. The main type of pneumoconiosis was silicosis, which was concentrated in regions, industries and types of work. We should continue to strengthen the prevention and treatment of pneumoconiosis.

Alteration of relative telomere length and telomerase reverse transcriptase expression in the granulosa cells of women during aging and assessment of in vitro fertilization outcomes

Telomere attrition plays a critical role in the reproductive aging process in humans. Telomere length (TL) is typically regulated by telomerase, the main component of which is telomerase reverse transcriptase (TERT). The aim of the present study was to investigate the changes of relative TL (RTL) and TERT expression in granulosa cells (GCs) during aging and its association with reproduction. Clinical data on the frozen‑thawed embryo transfer cycles of older (>35 year old) and younger (≤35 year old) women from a single center over a 3‑year period were retrospectively analyzed. Preimplantation genetic testing for chromosome aneuploidies in older women during the same period was also analyzed. Following the analysis of the data, several biological characteristics of senescent GCs were explored. In addition, a total of 160 women who were undergoing their first fresh cycle of in vitro fertilization (IVF) or intracytoplasmic sperm injection were included in the study. GCs were collected from all participants. The changes of RTL and TERT expression in GCs during aging were investigated using quantitative PCR and western blotting. The associations of RTL and TERT with IVF outcomes were also assessed. The clinical data demonstrated that the pregnancy and live birth rates of women aged >35 years were ~20% lower than those of women aged ≤35 years, and the number of embryos with aneuploidy was 7‑fold of that without euploidy in the older age group. An aging‑induced change in follicle stimulating hormone receptor expression was observed. A shorter TL and increased TERT expression were detected in the older women. A significant inverse correlation between the expression levels of TERT and oocyte yield was identified. However, no association of RTL and TERT with blastocyst formation rate and the probability of clinical pregnancy was detected. It may be concluded that RTL and TERT alterations in GCs are potential determinants of ovarian aging. TERT expression in GCs appears to be a potential biomarker for the prediction of ovarian response, which provides a novel strategy for the assessment of female fertility.

Mediating effect of gastrointestinal symptoms on dietary behavior and quality of life in Chinese adults with chronic gastritis-a cross-sectional study

Background

Chronic gastritis is accompanied by varying degrees of gastrointestinal symptoms, which affect people's quality of life. The association between dietary behaviors and gastrointestinal symptoms of patients with chronic gastritis has been proved recently. However, no studies have been conducted to investigate the relationship between dietary behaviors, gastrointestinal symptoms, and quality of life.

Methods

A cross-sectional survey of 176 patients diagnosed with chronic gastritis aged 18 to 65 years, comprising their information on demographic characteristics, dietary behaviors, gastrointestinal symptoms, and quality of life, was collected. A descriptive analysis and a correlation matrix were used to illuminate the characteristics of the subjects and bivariate correlation, respectively. The mediation model was analyzed using the PROCESS macros for SPSS.

Results

Demographic characteristics were found to influence the symptoms, dietary behaviors, and quality of life of chronic gastritis patients; in particular, students categorized by occupation had higher levels of gastrointestinal symptoms and lower levels of quality of life and dietary behavior. The study variables were all pound related. We found that gastrointestinal symptoms played a partial mediating role between dietary behavior and both the physical components summary and mental components summary, and the ratios of mediating effects to the total effect on the physical components summary and mental components summary were 23.5% and 21.5%, respectively.

Conclusion

Our survey discovered that dietary behavior, gastrointestinal symptoms, and quality of life were all pairwise related. The effect of dietary behavior on quality of life was partially mediated by gastrointestinal symptoms. These results may provide a novel perspective for medical staff in improving the quality of life of patients with chronic gastritis.

[Epidemiological characteristics of pesticide poisoning in Chengdu City from 2012 to 2021]

Objective: To explore the present situation and epidemiological characteristics of pesticide poisoning in Chengdu City from 2012 to 2021, and to provide scientific evidence for further prevention and control. Methods: In January 2022, the pesticide poisoning report cards of Chengdu City from 2012 to 2021 were collected from the China Disease Control and Prevention Information System. The data of the report card was reorganized and the distribution characteristics of pesticide poisoning such as time, region, gender, age and pesticide types were analyzed. Results: 14326 cases of pesticide poisoning were reported in Chengdu City from 2012 to 2021, 651 deaths, and the fatality rate was 4.54%. The cases of productive pesticide poisoning and unproductive pesticide poisoning were 504 and 13822, respectively. The fatality rates of productive and unproductive pesticide poisoning were 1.39% and 4.66%, which were significant different (χ(2)=11.99, P=0.001). The highest reported cases of pesticide poisoning was in 2013 (1779) and the lowest in 2021 (1047). The number of reported cases showed a downward trend year by year (t=-12.30, P<0.001), and the fatality rates also showed a downward trend year by year (χ(2)(trend)=25.48, P<0.001). The fluctuation range of unproductive pesticide poisoning cases in each month of the year was small, and the productive pesticide poisoning mainly occurred from May to August. The regions with the largest number of reported poisoning cases were Pengzhou (1620), Jianyang (1393), Jintang (1266) and Qionglai (1158). The high incidence of poisoning was among 25-54 years old (50.21%, 7193/14326). The fatality rate in the age group 75-96 years old was the highest (8.98%, 95/1058), and the fatality rates increased gradually with age (χ(2)(trend)=186.03, P<0.001). The pesticides causing poisoning were mainly insecticide (43.86%, 6284/14326) and herbicides (35.75%, 5121/14326). Herbicides paraquat had the highest fatality rate (9.54%, 286/2998) . Conclusion: Pesticide poisoning in Chengdu City is mainly unproductive poisoning. Health education should be carried out for key areas and people, and the control of highly toxic pesticides such as insecticide and herbicides should be strengthened.

Roles of the gut microbiota in severe SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The pathophysiological mechanisms linking gut dysbiosis and severe SARS-CoV-2 infection are poorly understood, although gut microbiota disorders are related to severe SARS-CoV-2 infections. The roles of the gut microbiota in severe SARS-CoV-2 infection were compared with those in respiratory viral infection, which is an easily understood and enlightening analogy. Secondary bacterial infections caused by immune disorders and antibiotic abuse can lead to dysregulation of the gut microbiota in patients with respiratory viral infections. The gut microbiota can influence the progression of respiratory viral infections through metabolites and the immune response, which is known as the gut–lung axis. Angiotensin-converting enzyme 2 is expressed in both the lungs and the small intestine, which may be a bridge between the lung and the gut. Similarly, SARS-CoV-2 infection has been shown to disturb the gut microbiota, which may be the cause of cytokine storms. Bacteria in the gut, lung, and other tissues and respiratory viruses can be considered microecosystems and may exert overall effects on the host. By referencing respiratory viral infections, this review focused on the mechanisms involved in the interaction between SARS-CoV-2 infections and the gut microbiota and provides new strategies for the treatment or prevention of severe SARS-CoV-2 infections by improving gut microbial homeostasis.

Impacts of psychological resilience on self-efficacy and quality of life in patients with diabetic foot ulcers: a prospective cross-sectional study

BACKGROUND

Patients with diabetic foot ulcer (DFU) usually have a poor quality of life (QoL) and self-efficacy, which is affected by many risk factors. However, the role of psychological resilience in QoL and self-efficacy in DFU patients has remained unclear.

METHODS

This prospective cross-sectional study was performed in a single center from January 2018 to February 2020. A total of 98 DFU patients were enrolled in this study. Some demographic and clinical data were prospectively collected from participants. The psychological resilience of participants was assessed by Connor-Davidson resilience scale (CD-RISC). Self-efficacy was also assessed using the diabetes management self-efficacy scale (DMSES) and QoL was assessed by the 36-item short-form (SF-36) health survey. Univariable and multivariable linear regression were used to analyze the risk factors of self-efficacy and QoL. Then, logistic regression was used to analyze the predictors of psychological resilience among the participants.

RESULTS

A CD-RISC score of more than 85 points was defined as high psychological resilience in this study; there were 28 participants diagnosed with high psychological resilience and 70 patients with low psychological resilience. Those with high psychological resilience had significantly higher self-efficacy, general health, vitality, social functioning, role emotional, and mental health than those with low psychological resilience. According to multivariable linear regression, low psychological resilience and older age were identified as risk factors of self-efficacy. On the contrary, low psychological resilience, older age, lower perceived social support and higher level of glycated hemoglobin were identified as risk factors of QoL. Finally, males had lower psychological resilience than females and those receiving more social support had higher psychological resilience than participants receiving less social support.

CONCLUSIONS

Some risk factors of QoL and self-efficacy were identified in this study and these results may provide some evidence for the improvement of QoL and self-efficacy in DFU patients. Being female and receiving higher social support were shown to have potential for improving psychological resilience in DFU patients.

[High frequency hearing loss detection rate in occupational noise exposed workers in China: a Meta-analysis]

Objective: A Meta-analysis was used to evaluate the high frequency hearing loss detection rate, its area and time distributions in occupational noise exposed workers in China to provide evidence for the prevention and control of occupational noise-induced deafness. Methods: From February to April 2020, the number of hearing tests and the number of binaural high frequency average hearing threshold ≥40 dB of workers exposed to noise in key occupational disease monitoring and occupational health risk assessment project in China was collected from China National Knowledge Infrastructure (CNKI) , VIP database and PubMed database. The retrieval time was set from the establishment of the database to February 28, 2020. The R 3.6.2 software was used to calculate the pooled high frequency hearing loss detection rate. Results: A total of 28 studies, included 34 data and 1259571 occupational noise exposed workers, were enrolled. The articles covered 16 provinces in 2015-2018. The pooled high frequency hearing loss detection rate in occupational noise exposed workers was 9.45% (95%CI: 7.64%-11.64%) . The high frequency hearing loss detection rate (10.54%) was higher in 2018 than other years (2017: 10.17%, 2016: 9.21%, 2015: 7.88%) . The high frequency hearing loss detection rate (12.23%) was higher in central China than in eastern (10.21%) , western (7.91%) and north-eastern (5.21%) China. Conclusion: The overall high frequency hearing loss detection rate in occupational noise exposed workers is generally high in China. It is important to strengthen the hearing protection in occupational noise exposed workers to facilitate the occupational noise-induced deafness prevention and control in China.

[Influencing factors on smoking cessation among outpatients from the National Central Subsidy Smoking Cessation Clinic Project, in 2015-2018]

Objective: To evaluate the effect of smoking cessation project run by the Central Subsidy Smoking Cessation Clinic and to explore the related influencing factors on smoking cessation, in order to improve related services and provide better guidance to these smoking cessation clinics. Methods: Practitioners who had been trained to run smoking cessation projects were recruited to conduct face-to-face interview with the smokers. Questionnaires were completed to provide information on related psychological, social and behavioral issues. In these clinics, medications were provided to the patients by the health care takers in the clinic. One month after the first visit, smoking cessation rate (self-reported, 7-day point prevalence abstinence rate at 30-day follow-up) was counted. Results: The overall smoking cessation rate (self-reported, 7-day point prevalence abstinence rate at 30-day follow-up) appeared as 34.1%. Results from the multivariate logistic regression showed that patients over the age of 60 were the ones most likely to quit smoking. Smokers who showed higher possibility of quitting would include those: not on the daily base, intend to quit within 30 days, with other diseases, or taking varenicline and bupropion. Factors as unemployment, longer history of smoking, bigger quantity of cigarettes consumption per day, dependence on nicotine and urgency on taking up the first cigarette in the early morning etc., were related to the less likelihood of giving up smoking. However, histories of cessation did not seem to affect the possibility of quitting. Conclusions: Data from self-reported 7-day point prevalence abstinence at 30-day follow-up study showed that the smoking cessation intervention programs run by the central subsidy smoking cessation clinic project had been effectively implemented. Advocacy on quit smoking at early stage seemed to have better outcomes, thus should be called for. Since medications as varenicline tartrate and bupropion hydrochloride can increase the possibility of stop smoking, we would suggest that all the hospitals which are with smoking cessation clinics be equipped with these medicines. Professional assistance provided by practitioners is of key importance to help overcome the withdrawal symptoms during the periods of cessation, on these smokers.

Bilateral high-frequency hearing loss is associated with elevated blood pressure and increased hypertension risk in occupational noise exposed workers

Objective

To investigate the association of bilateral high-frequency hearing loss (BHFHL) with blood pressure and hypertension among occupational noise exposed workers.

Methods

Occupational noise exposed workers were enrolled in 2017 from the occupational diseases survey of Chengdu. BHFHL was classified as normal, mild, or high by the bilateral high-frequency tone average. Linear regression model was used to assess the effects of occupational noise exposure time and BHFHL on blood pressure. Logistic regression model was performed to estimate hypertension risk odds ratios (ORs) associated to occupational noise exposure time and BHFHL.

Results

Increasing years of occupational noise exposure and BHFHL were significantly associated with systolic and diastolic blood pressure increase (all P<0.001). The lineal trend was only significant in males, with adjusted ORs for hypertension gradually increasing with increasing years of occupational noise exposure (P<0.001). Furthermore, subjects having mild and high BHFHL had a higher hypertension risk of 34% and 281%, respectively (both P<0.001). Dose-response relationship between BHFHL and hypertension was found in both males and females.

Conclusions

Occupational noise exposure was positively associated with blood pressure levels and hypertension risk.

Co-exposure to metals and polycyclic aromatic hydrocarbons, microRNA expression, and early health damage in coke oven workers

BACKGROUND

All humans are now co-exposed to multiple toxic chemicals, among which metals and polycyclic aromatic hydrocarbons (PAHs) are of special concern as they are often present at high levels in various human environments. They can also induce similar early health damage, such as genetic damage, oxidative stress, and heart rate variability (HRV). Exposure to metals, PAHs, and their combined pollutants can alter microRNA (miRNA) expression patterns.

OBJECTIVES

To explore the associations of metal-PAH co-exposure with miRNA expression, and of the associated miRNAs with early health damage.

METHODS

We enrolled 360 healthy male coke oven workers and quantified their exposure levels of metals and PAHs by urinary metals, urinary monohydroxy-PAHs (OH-PAHs), and plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, respectively. We selected and measured ten miRNAs: let-7b-5p, miR-126-3p, miR-142-5p, miR-150-5p, miR-16-5p, miR-24-3p, miR-27a-3p, miR-28-5p, miR-320b, and miR-451a. For miRNAs influenced by the effect modification of metals or PAHs and/or metal-PAH interactions, we further evaluated their associations with biomarkers for genetic damage, oxidative stress, and HRV.

RESULTS

After adjusting for PAHs and other metals, miRNA expression was found to be negatively associated with aluminum, antimony, lead, and titanium, and positively associated with molybdenum and tin (p < 0.05). Antimony showed modifying effects on the PAH-miRNA associations, while OH-PAHs and BPDE-Alb adducts modified the associations of metals with miRNAs (p for modifying effect < 0.05). Furthermore, miRNA expression was influenced by the antagonistic interactions between antimony and OH-PAHs, and by the synergistical interactions between metals and BPDE-Alb adducts (p_interaction < 0.05). Let-7b-5p, miR-126-3p, miR-16-5p, and miR-320b were additionally found to be associated with increased genetic damage in the present study [false discovery rate (FDR)-adjusted p < 0.05].

CONCLUSIONS

Associations of metal-PAH co-exposure with miRNA expression, and of associated miRNAs with early health damage, suggested potential mechanistic connections between the complex metal-PAH interactions and their deleterious effects that are worthy of further investigation.

The Vicenza “Short” Peritoneal Catheter: A Twenty Year Experience

Dislocation of peritoneal dialysis catheters is one of the major causes of technique failure. We evaluated 701 Vicenza catheters, implanted since 1985 in 365 males, mean age 53 ± 16 yrs, range 24 - 87, and 336 females, mean age 51 ± 17 yrs, range 21 - 82. The Vicenza catheter is defined “short” since it consists of a classic straight double cuff PD catheter having however an inner segment (the portion located in the peritoneal cavity) much shorter than any other type of catheter. It is implanted in the lower abdomen, just a few centimeters above the pubis. The analysis of our results obtained in a large PD population displayed good device survival at 2 and 5 years (94.3% and 91.5% respectively), a low dislocation rate (4%) and an exit-site infection rate similar to other double cuffed catheters. There was no selection of patients receiving this catheter since from 1985 we have used this catheter in every incident patient. Due to its lower implantation site this catheter demonstrates excellent wearability and good body image acceptance.

Development and validation of a fluoride bone injury risk prediction model

BACKGROUND

Fluoride bone injury affects millions of people exposed to fluoride worldwide, and has no treatment - prevention is the only solution.

OBJECTIVES

A risk prediction model was developed to identify workers at high risk for fluoride bone injury in aluminum production.

METHODS

We collected data from the Molecular Epidemiology Study of Fluoride Bone Injury. 120 fluoride bone injury cases and 120 controls were involved in the study. Logistic regression was used to determine variables in the risk prediction model. Predictive accuracy was validated with bootstrap method. Potential risk cut-offs was evaluated with receiver operating characteristic curve.

RESULTS

Working history, urinary fluoride, osteocalcin, bone alkaline phosphatase and calcitonin receptor gene polymorphism were included in the final prediction model. The model had very good calibration and discrimination (C index=0.986; Brier score 0.014).

CONCLUSIONS

Our fluoride bone injury risk prediction model performed well in the present data, and the working history, urinary fluoride, osteocalcin, bone alkaline phosphatase, and calcitonin receptor gene polymorphism were identified as predictors. The model could be used to assess the fluoride bone injury risk, and identify the susceptible workers.

Genome-Wide Analysis of DNA Methylation and Cigarette Smoking in a Chinese Population

BACKGROUND

Smoking is a risk factor for many human diseases. DNA methylation has been related to smoking, but genome-wide methylation data for smoking in Chinese populations is limited.

OBJECTIVES

We aimed to investigate epigenome-wide methylation in relation to smoking in a Chinese population.

METHODS

We measured the methylation levels at > 485,000 CpG sites (CpGs) in DNA from leukocytes using a methylation array and conducted a genome-wide meta-analysis of DNA methylation and smoking in a total of 596 Chinese participants. We further evaluated the associations of smoking-related CpGs with internal polycyclic aromatic hydrocarbon (PAH) biomarkers and their correlations with the expression of corresponding genes.

RESULTS

We identified 318 CpGs whose methylation levels were associated with smoking at a genome-wide significance level (false discovery rate < 0.05), among which 161 CpGs annotated to 123 genes were not associated with smoking in recent studies of Europeans and African Americans. Of these smoking-related CpGs, methylation levels at 80 CpGs showed significant correlations with the expression of corresponding genes (including RUNX3, IL6R, PTAFR, ANKRD11, CEP135 and CDH23), and methylation at 15 CpGs was significantly associated with urinary 2-hydroxynaphthalene, the most representative internal monohydroxy-PAH biomarker for smoking.

CONCLUSION

We identified DNA methylation markers associated with smoking in a Chinese population, including some markers that were also correlated with gene expression. Exposure to naphthalene, a byproduct of tobacco smoke, may contribute to smoking-related methylation.

CITATION

Zhu X, Li J, Deng S, Yu K, Liu X, Deng Q, Sun H, Zhang X, He M, Guo H, Chen W, Yuan J, Zhang B, Kuang D, He X, Bai Y, Han X, Liu B, Li X, Yang L, Jiang H, Zhang Y, Hu J, Cheng L, Luo X, Mei W, Zhou Z, Sun S, Zhang L, Liu C, Guo Y, Zhang Z, Hu FB, Liang L, Wu T. 2016. Genome-wide analysis of DNA methylation and cigarette smoking in Chinese. Environ Health Perspect 124:966-973; http://dx.doi.org/10.1289/ehp.1509834.

The effects of heavy metals and their interactions with polycyclic aromatic hydrocarbons on the oxidative stress among coke-oven workers

Heavy metals and polycyclic aromatic hydrocarbons (PAHs) are predominate toxic constituents of particulate air pollution that may be related to the increased risk of cardiopulmonary events. We aim to investigate the effects of the toxic heavy metals (arsenic, As; cadmium, Cd; chromium, Cr; nickel, Ni; and lead, Pb), and their interactions with PAHs on oxidative stress among coke-oven workers. A total of 1333 male workers were recruited in this study. We determined their urinary levels of As, Cd, Cr, Ni, Pb, twelve PAH metabolites, 8-hydroxydeoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α). Multivariate linear regression models were used to analyze the effects of these metals and their interactions with PAHs on 8-OHdG and 8-iso-PGF2α levels. It was found that only urinary As and Ni showed marginal or significant positive linear dose-dependent effects on 8-OHdG in this study population, especially among smokers (β=0.103, P=0.073 and β=0.110, P=0.002, respectively). After stratifying all participants by the quartiles of ΣOH-PAH, all five metals showed linear association with 8-OHdG in the highest quartile subgroup (Q4) of ΣOH-PAHs. However, these five urinary metals showed significantly consistent linear associations with 8-iso-PGF2α in all subjects and each stratum. Urinary ΣOH-PAHs can significant modify the effects of heavy metals on oxidative stress, while co-exposure to both high levels of ΣOH-PAHs and heavy metals render the workers with highest 8-OHdG and 8-iso-PGF2α (all P(interaction)≤0.005). This study showed evidence on the interaction effects of heavy metals and PAHs on increasing the oxidative stress, and these results warrant further investigation in more longitudinal studies.

Association between the HSPA1B ±1267A/G polymorphism and cancer risk: a meta-analysis of 14 case-control studies

BACKGROUND

Previous epidemiological studies have suggested a potential role of the HSPA1B±1267A/G polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk.

MATERIALS AND METHODS

We retrieved relevant articles from PubMed, EMBASE, ISI Web of Science, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure. Studies were selected using specific criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess those associations. All analyses were performed using STATA software.

RESULTS

Fourteen case-control studies, including 1, 834 cancer cases and 2, 028 controls were included in this meta-analysis. Overall, the results indicated that the G allele of HSPA1B gene ±1267A/G was significantly associated with an increased cancer risk in all genetic models (G vs A: OR=1.51, 95%CI 1.17-1.95, p=0.001; GG vs AA: OR=2.93, 95%CI 1.50-5.74, p=0.002; AG vs AA: OR=1.48, 95%CI 1.10-1.98, p=0.009; GG/AG vs AA: OR=1.69, 95%CI 1.22-2.33, p=0.001; GG vs

AG/AA

OR=2.31, 95%CI 1.24-4.32, p=0.009). In the subgroup analysis stratified by ethnicity, a significant association was identified in Caucasians (G vs A: OR=1.35, 95%CI 1.08-1.69, p=0.008; GG/AG vs AA: OR=1.36, 95%CI 1.09-1.70, p=0.007), but not in Asians. In the stratified analysis by cancer types, individuals with the G allele showed an increased risk of hepatocellular carcinoma compared with carriers of the A allele (OR=2.40, 95%CI 1.47-3.91, p< 0.001). Inversely, individuals with the GG genotype showed a decreased risk of gastric cancer compared with carriers of the AG/GG genotypes (GG vs

AG/AA

OR=0.39, 95%CI 0.20-0.70, p=0.007).

CONCLUSIONS

This meta-analysis suggests associations between the HSPA1B ±1267A/G polymorphism and risk of cancer. However, this association might be Caucasian-specific and the G allele of this polymorphism probably increases risk of hepatocellular carcinoma while decreasing risk of gastric cancer. Further well-designed studies based on larger sample sizes are needed to validate these findings.

Women are more susceptible than men to oxidative stress and chromosome damage caused by polycyclic aromatic hydrocarbons exposure

Exposure to environmental polycyclic aromatic hydrocarbons (PAHs) has been associated with increased risk of cancer, but evidence for gender differences in this association is limited. The aim of this study was to examine the gender differences in PAHs caused early genotoxic effects such as oxidative stress and chromosome damage, which are potential carcinogenic etiology of PAHs. A total of 478 nonsmoking workers (272 men and 206 women) from a coke oven plant were recruited. We determined 16 environmental PAHs in their workplaces, and measured concentrations of 12 urinary PAH metabolites (OH-PAHs), plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, urinary 8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α), and micronucleus frequencies in lymphocytes in all subjects. It showed that, women working at the office, adjacent to the coke oven, and on the bottom or side of the coke oven displayed significantly higher levels of urinary 8-OHdG and 8-iso-PGF2α, and lymphocytic micronucleus frequencies compared with men working at above areas, respectively (all P < 0.05). These gender differences remain significant after adjusted for potential confounders and urinary ΣOH-PAHs or plasma BPDE-Alb adducts. A significant interaction existed between gender and BPDE-Alb adducts on increasing micronucleus frequencies (Pinteraction  < 0.001). We further stratified all workers by the tertiles of urinary ΣOH-PAHs or plasma BPDE-Alb adducts, and the above gender differences were more evident in the median- and high-exposure groups (all P < 0.05). In conclusion, women were more susceptible than men to oxidative stress and chromosome damage induced by PAHs, which may add potential evidence underlying gender differences in PAH exposure-related lung cacinogenesis.

Organic extracts of coke oven emissions can induce genetic damage in metabolically competent HepG2 cells

Coke oven emissions (COEs) containing various carcinogenic polycyclic aromatic hydrocarbons (PAHs) represent the coal-burning pollution in the air. Organic pollutants in the aerosol and particulate matter of COEs were collected from the bottom, side, and top of a coke oven. The Comet assay and cytokinesis-block micronucleus cytome assay were conducted to analyze the genetic damage of extractable organic matter (EOM) of COEs on HepG2 cells. All the three EOMs could induce significant dose-dependent increases in Olive tail moment, tail DNA, and tail length, micronuclei, nucleoplasmic bridges, and nuclear buds frequencies, which were mostly positively correlated with the total PAHs concentration in each EOM. In conclusion, EOMs of COEs in the three typical working places of coke oven can induce DNA strand breaks and genomic instability in the metabolically competent HepG2 cells. The PAHs in EOMs may be important causative agents for the genotoxic effects of COEs.

Polycyclic aromatic hydrocarbons-associated microRNAs and their interactions with the environment: influences on oxidative DNA damage and lipid peroxidation in coke oven workers

We previously identified five polycyclic aromatic hydrocarbons (PAHs)-associated microRNAs (miRNAs) and found they were associated with chromosome damage. As oxidative damage is the common contributory cause of various PAHs-related diseases, we further investigated the influences of these miRNAs and their interactions with environmental factors on oxidative DNA damage and lipid peroxidation. We measured PAHs internal exposure biomarkers [urinary monohydroxy-PAHs (OH-PAHs) and plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts], the expression levels of PAHs-associated plasma miRNAs (miR-24-3p, miR-27a-3p, miR-142-5p, miR-28-5p, and miR-150-5p), and urinary biomarkers of oxidative DNA damage [8-hydroxydeoxyguanosine (8-OH-dG)] and lipid peroxidation [8-iso-prostaglandin-F2α (8-iso-PGF2α)] in 365 healthy male coke oven workers. These miRNAs were associated with a dose-response increase in 8-OH-dG (β > 0), and with a dose-response decrease in 8-iso-PGF2α (β < 0), especially in workers with lower PAHs exposure levels, in nonsmokers, and in nondrinkers. These miRNAs interacted antagonistically with ΣOH-PAHs and BPDE-Alb adducts (βinteraction < 0) and synergistically with drinking status (βinteraction > 0) to influence 8-OH-dG, while they interacted synergistically with BPDE-Alb adducts (βinteraction > 0) and antagonistically with smoking status (βinteraction < 0) to influence 8-iso-PGF2α. Our results suggested that miRNAs and their interactions with environmental factors might be novel mechanisms mediating the effects of PAHs exposure on oxidative DNA damage and lipid peroxidation.

Dose-response relationships of polycyclic aromatic hydrocarbons exposure and oxidative damage to DNA and lipid in coke oven workers

Polycyclic aromatic hydrocarbons (PAHs) are known to induce reactive oxygen species and oxidative stress, but the dose-response relationships between exposure to PAHs and oxidative stress levels have not been established. In this study, we recruited 1333 male coke oven workers, monitored the levels of environmental PAHs, and measured internal PAH exposure biomarkers including 12 urinary PAH metabolites and plasma benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, as well as the two oxidative biomarkers urinary 8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α). We found that the total concentration of urinary PAH metabolites and plasma BPDE-Alb adducts were both significantly associated with increased 8-OHdG and 8-iso-PGF2α in both smokers and nonsmokers (all p < 0.05). This exposure-response effect was also observed for most PAH metabolites (all p(trend) < 0.01), except for 4-hydroxyphenanthrene and 8-OHdG (p(trend) = 0.108). Furthermore, it was shown that only urinary 1-hydroxypyrene has a significant positive association with both 8-OHdG and 8-iso-PGF2α after a Bonferroni correction (p < 0.005). Our results indicated that urinary ΣOH-PAHs and plasma BPDE-Alb adducts can result in significant dose-related increases in oxidative damage to DNA and lipids. Furthermore, when a multianalyte method is unavailable, our findings demonstrate that urinary 1-hydroxypyrene is a useful biomarker for evaluating total PAHs exposure and assessing oxidative damage in coke oven workers.

[Influence of ethylbenzene on oxidative damage and apoptosis in rat renal epithelial cells NRK-52e]

OBJECTIVE

To study the oxidative damage and apoptosis of renal tubular epithelial cells (NRK-52e cell line) induced by ethylbenzene.

METHODS

NRK-52e cells were exposed to 30, 60, 90, 120 μmol/L ethylbenzene for 24 hours. Cell viability were measured using MTT, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), the contents of malondialdehyde (MDA) and glutathione (GSH) were detected respectively. PI fluorescent staining assay was applied to detect percentage of apoptosis in ethylbenzene-treated groups.

RESULTS

Compared with control group, cell outline became clear, cell diopter increased, cell became smaller and shrinkage, some cells broke in 60 μmol/L ethylbenzene-treated group. Plenty of cells died, suspension cells increased significantly in 90 μmol/L ethylbenzene-treated group. Compared with control group, cell viability the activities of SOD and CAT and the content of GSH were significantly decreased in 60 and 90 μmol/L ethylbenzene-treated groups (P<0.05). The MDA content were remarkably elevated in 90 μmol/L ethylbenzene-treated groups (P<0.05).

CONCLUSION

Ethylbenzene can induce oxidative stress and apoptosis in NRK-52e cells (P<0.05).

[Characteristics of particulate matter pollution in coke oven plant]

OBJECTIVE

To explore the characteristics of particulate matter pollution in coke oven plant, so as to provide scientific data for establishing occupational exposure limits for coke oven emissions.

METHODS

Concentrations of CO, SO₂, BSM, BTEX (concentrations of benzene, toluene and xylene were determined in this study), PM₁₀, PM₂.₅, 16 selected PAHs in PM₁₀ and PM₂.₅ were determined in the work environment of a coke oven plant in Wuhan. The work environment was divided into the adjunct area, the bottom of, the side of and the top of coke oven.

RESULTS

The concentrations of CO, SO₂, BSM, BETX, PM₁₀, PM₂.₅, PAHs in PM₁₀ and PM₂.₅ were significantly related to working environmental categories, respectively, and were increasing as the adjunct area < bottom < side < top (P (trend) < 0.05). PM₁₀ was statistically significantly correlated with CO, SO₂, benzene, BTEX and BSM (0.705, 0.823, 0.664, 0.624 and 0.734, respectively). PM₂.₅ was statistically significantly correlated with CO, SO₂, benzene, BTEX and BSM (0.635, 0.916, 0. 680, 0.553 and 0.726, respectively). BSM was statistically significantly correlated with benzene (0.689). The ratios of PM₂.₅ to PM₁₀ between different work environments were not significantly different in one-way ANOVA (P > 0.05). The distribution of aromatic rings and the concentrations of total benzo[a] pyrene equivalents in PM₁₀ and PM₂.₅ were not statistically different between work environments.

CONCLUSION

The concentrations of particulate matter was related with other contents of coke oven emissions in coke work environment, and the contents and types of PAHs in PM₁₀ and PM₂.₅ were similar.

[Using the stable HSPA1A promoter-driven luciferase reporter HepG2 cells to assess the overall toxicity of coke oven emissions]

OBJECTIVE

Using the stable HSPA1A (HSP70-1) promoter-driven luciferase reporter HepG2 cells (HepG2/HSPA1A cells) to assess the overall toxicity of coke oven emissions.

METHODS

The stable HepG2/HSPA1A cells were treated with different concentrations of coke oven emissions (COEs) collected from the top, side, and bottom of a coke oven battery for 24 h. After the treatments, luciferase activity, cell viability, malondialdehyde (MDA) concentration, Olive tail moment, and micronuclei frequency were determined, respectively.

RESULTS

The bottom COEs induced significant increases (P < 0.01) in relative luciferase activity up to 1.4 times the control level at 0.15 µg/L. The low dose of side COEs (0.02 µg/L) led to a significant increase (P < 0.01) in relative luciferase activity that progressively increased to 2.1 times the control level at 65.4 µg/L. The top COEs produced a strong dose-dependent induction of relative luciferase activity up to over 5 times the control level at the highest concentration tested (202 µg/L). In HepG2/HSPA1A cells treated with the bottom COEs, relative luciferase activity was positively correlated with MDA concentration (r = 0.404, P < 0.05). For the three COEs samples, positive correlations were observed between relative luciferase activity and Olive tail moment and micronuclei frequency.

CONCLUSION

The relative luciferase activity in HepG2/HSPA1A cells can sensitively reflect the overall toxicity of COEs. The stable HepG2/HSPA1A cells can be used for rapid screening of the overall toxicity of complex air pollutants in the workplace.

[Effects of smoking on the concentrations of urinary 10 metabolites of polycyclic aromatic hydrocarbons in coke oven workers]

OBJECTIVE

To explore the effects of smoking on urinary 10 metabolites of polycyclic aromatic hydrocarbons (PAHs) in the coke oven workers.

METHODS

Occupational health examination was performed on 1401 coke oven workers in one coking plant, their urine were collected respectively. The concentrations of the ten monohydroxy polycyclic aromatic hydrocarbons in urine were detected by gas chromatography/mass spectrometry. The 1401 workers were divided into four groups, namely control, adjunct workplaces, bottom and side, top group according to their workplaces and the different concentrations of PAHs in the environment. The concentrations of the ten monohydroxy polycyclic aromatic hydrocarbons between smokers and nonsmokers in each workplace group were compared using analysis of covariance, respectively.

RESULTS

The levels of concentrations of the sixteen polycyclic aromatic hydrocarbons we detected at control were significantly higher than those at other areas (P < 0.05). Comparing the ten monohydroxy polycyclic aromatic hydrocarbons levels between smokers and nonsmokers, the levels of 1-hydroxynaphthalene and 2-hydroxynaphthalene among smokers were higher than nonsmokers with statistically significance in control, adjunct workplaces, bottom and side and top groups (P < 0.05). However, the levels of 1-hydroxypyrene had no statistically significant differences between the four areas.

CONCLUSION

Urinary 1-hydroxynaphthalene and 2-hydroxynaphthalene may be used as biomarkers for the impact of smoking on monohydroxy polycyclic aromatic hydrocarbons in the coke oven workers.

The dose-response decrease in heart rate variability: any association with the metabolites of polycyclic aromatic hydrocarbons in coke oven workers?

Background

Air pollution has been associated with an increased risk of cardiopulmonary mortality and decreased heart rate variability (HRV). However, it is unclear whether coke oven emissions (COEs) and polycyclic aromatic hydrocarbons (PAHs) are associated with HRV.

Objectives

Our goal in the present study was to investigate the association of exposure to COEs and the urinary metabolite profiles of PAHs with HRV of coke oven workers.

Methods

We measured benzene soluble matter, carbon monoxide, sulfur dioxide, particulate matters, and PAHs at different workplaces of a coke oven plant. We determined 10 urinary PAH metabolites and HRV indices of 1333 workers using gas chromatography–mass spectrometry and a 3-channel digital Holter monitor, respectively.

Results

Our results showed that there was a significant COEs-related dose-dependent decrease in HRV, and an inverse relationship between the quartiles of urinary 2-hydroxynaphthalene and five HRV indices (p_trend<0.01 for all). After adjustment for potential confounders, elevation per interquartile range (IQR) (1.81 µg/mmol creatinine) of urinary 2-hydroxynaphthalene was associated with a 5.46% (95% CI, 2.50–8.32) decrease in standard deviation of NN intervals (SDNN). As workers worked more years, SDNN gradually declined in the same quartiles of 2-hydroxynaphthalene levels (p_trend = 1.40×10⁻⁴), especially in workers with the highest levels of 2-hydroxynaphthalene.

Conclusions

Occupational exposure to COEs is associated with a dose-response decrease in HRV. In particular, increased exposure to 2-hydroxynaphthalene is associated with significantly decreased HRV. Increase of working years and exposure levels has resulted in a gradual decline of HRV.

Development of stable HSPA1A promoter-driven luciferase reporter HepG2 cells for assessing the toxicity of organic pollutants present in air

HSPA1A (HSP70-1) is a highly inducible heat shock gene up-regulated in response to environmental stresses and pollutants. The aim of our study was to evaluate the sensitivity of the stable metabolically competent HepG2 cells containing a human HSPA1A promoter-driven luciferase reporter (HepG2-luciferase cells) for assessing the toxicity of organic pollutants present in air. The HepG2-luciferase cells were validated by heat shock treatment and testing three organic compounds (pyrene, benzo[a]pyrene, and formaldehyde) that are ubiquitous in the air. The maximal level of HSPA1A (HSP70-1) and relative luciferase activity induced by heat shock were over three and nine times the control level, respectively. Pyrene, benzo[a]pyrene, and formaldehyde all induced significantly elevated levels of relative luciferase activity in a dose-dependent manner. Extractable organic matter (EOM) from urban traffic and coke oven emissions in ambient air were tested on the HepG2-luciferase cells. The traffic EOM induced significant increase in relative luciferase activity at concentrations of picogram per liter. The coke oven EOM produced a strong dose-dependent induction of relative luciferase activity up to six times the control value. Significant increases in relative luciferase activity were observed at concentrations that were as low, or lower than the concentrations that the tested organic pollutants decreased cell viability, and increased malondialdehyde concentration, Olive tail moment, and micronuclei frequency. Therefore, we conclude that the HepG2-luciferase cells are a valuable tool for rapid screening of the overall toxicity of organic pollutants present in air.

[The increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers exposed accumulatively to formaldehyde]

OBJECTIVE

To investigate the effects of occupational exposure to formaldehyde on the micronuclei frequencies in peripheral blood lymphocytes of workers.

METHODS

Two hundred thirty six plywood workers were divided into 3 exposure groups (low, middle and high) according to internal exposure biomarker (formaldehyde human serum albumin conjugate, FA-HSA), which was detected by ELISA. The concentrations of formaldehyde (FA) in air of two workshops were measure using the high performance liquid chromatography. Cytokinesis-block micronucleus (CBMN) test was used to detect the micronuclei frequencies of peripheral blood lymphocyte in 236 workers.

RESULTS

The average concentrations of FA in the low and high exposure workshops were 0.58 +/- 0.20 and 1.48 +/- 0.61 mg/m3, respectively, there was significant difference (P < 0.01). The average concentrations of serum FA-HAS of workers in two workshops were 69.22 +/- 15.37 and 136.29 +/- 89.49 pg/ml, respectively, there was significant difference (P < 0.01). The results of CBMN test showed that the micronucleus frequencies in low, middle and high exposure groups were 1.94 +/- 1.72, 2.10 +/- 1.92 and 2.10 +/- 1.70 per thousand, respectively, there were no significant differences between groups. However, the micronucleus frequencies in accumulative low, middle and high exposure groups were 1.36 +/- 1.36, 2.31 +/- 1.81 and 2.49 +/- 1.92 per thousand, respectively, there were significant differences between different accumulative exposure groups (P < 0.01). The results of correlation analysis indicated that there was a positive correlation between accumulative exposure levels and micronucleus frequencies (r(s) = 0.321, P < 0.01). The accumulative exposure doses may be a risk factor for high micronucleus frequencies in workers exposed to FA (P(trend) = 0.002).

CONCLUSION

FA-HSA levels can serve as an internal exposure biomarker for assessing the exposure level of workers exposed to FA. Accumulative formaldehyde exposure resulted in an increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers.

Variations in HSPA1B at 6p21.3 are associated with lung cancer risk and prognosis in Chinese populations

The heat shock protein Hsp70 is crucial for regulating cellular homeostasis in stressed cells. Although the tumorigenic potential and prognostic applications of Hsp70 have been widely investigated, it remains unclear whether genetic variations of the human isoforms HSPA1L, HSPA1A, and HSPA1B are associated with cancer risk and prognosis. In this study, we genotyped six tagSNPs in these genes in 1,152 paired patients with lung cancer and controls, and then validated the results in additional cohorts of 1,781 patients with lung cancer and 1,038 controls. In addition, we evaluated the associations of these tagSNPs with survival in 330 patients with advanced non-small cell lung cancer (NSCLC) with additional validation in another 331 patients with advanced NSCLC. Functions of the risk variants identified were investigated using cell-based reporter assays. We found that the HSPA1B rs6457452T allele was associated with increased lung cancer risk compared with the rs6457452C allele in both data sets and also pooled analysis (adjusted OR = 1.41; P = 2.8 × 10(-5)). The HSPA1B rs2763979TT genotype conferred poor survival outcomes for patients with advanced NSCLC in two independent cohorts and pooled analysis [adjusted hazard ratio (HR) = 1.80, 1.61, and 1.66; P = 0.013, 0.036, and 0.002, respectively]. Lastly, we also found that the rs2763979T and rs6457452T alleles were each sufficient to reduce expression of transcriptional reporter constructs, when compared with the rs2763979C and rs6457452C alleles, respectively. Taken together, our findings define that functional HSPA1B variants are associated with lung cancer risk and survival. These Hsp70 genetic variants may offer useful biomarkers to predict lung cancer risk and prognosis.

Pharmacokinetics and antimicrobial dosing adjustment in critically ill patients during continuous renal replacement therapy

Appropriate antimicrobial therapy poses one of the greatest challenges during the management of a septic patient in the intensive care unit (ICU). Acute renal failure (ARF) is a common complication of sepsis and often occurs as a component of multiple organ dysfunction syndrome. Continuous renal replacement therapy (CRRT) is increasingly used as an effective extracorporeal blood purification therapy in this critically ill patient population. Available data demonstrate that sepsis, ARF and different modalities of CRRT may have profound effects on the pharmacokinetics and pharmacodynamics of various antimicrobial agents used in the ICU. Guidelines for antimicrobial prescription which will fit the individual patient undergoing a particular method of treatment are still unavailable. Understanding the principles of drug removal by CRRT and pharmacokinetics of various agents can help to modify the drug dosage and dosing intervals for individualized therapy. Meanwhile, monitoring the drug serum concentration is still mandatory whenever clinically feasible.

[Three-dimensional surface reconstruction of spiral CT for teeth and clinical use in examining impacted teeth of jaws]

OBJECTIVE

To establish a new technique for three-dimensional surface reconstruction of teeth (dental surface reconstruction), and apply it to investigate impacted teeth in bone before operation.

METHODS

On the basis of three-dimensional surface reconstruction of teeth and jaws, the dental surface reconstruction is obtained with the technique of shaded surface display (SSD), making transparent bone around. This technique is applied to investigate 9 cases of supernumerary and impacted teeth.

RESULTS

Dental surface reconstruction image can present the dental surface image including crown, root, neck and root bifurcation in three-dimensional way, without presenting the image of other tissue around. In 4 cases, the abnormal configuration, labial or palatal location, and relation with dentition in anterior maxilla of 5 supernumerary were shown. In 1 case, the shape, location, eruption orientation and the angle of orthodontic distraction of 1 impacted permanent canine were displayed. In 3 cases, the shape, location, and extraction resistance of 6 impacted wisdom teeth were revealed. In 1 case, the configuration, distance to adjacent molar of 1 impacted wisdom tooth, which is a transposition tooth in maxillary sinus, were also demonstrated.

CONCLUSION

The dental surface reconstruction is a new technique to display three-dimensional surface configuration of teeth. This technique can be applied to examine impacted and supernumerary teeth before surgical and orthodontic treatment.

[Study on synthesis and molecular spectra of the N-(2-hydroxy) naphthylmethyleneamino iron(III), cobalt(II) and copper(II) complexes]

The title complexes were synthesized via reaction of iron nitrate, cobalt acetate and copper acetate with the didentate O,N-donor Schiff bases in methanol solution. The electronic and infrared spectra of these complexes were measured and the major IR bands were assigned.

[Fine physical mapping of yeast chromosome V]

Electrophoretic karyotype of yeast strain A364a was obtained by pulsed field gel electrophoresis and the position of chromosome V on such karyotype was determined by means of dot hybridization with chromosome V-specific probe URA3. By cloning partially digested BamHI fragments of this chromosome DNA into integrative vector Yip5, a gene library specific to this chromosome was constructed. The number of the recombinants was much more than theoretically required. After screening probe-homologous fragments from this library and analysing such fragments with restriction enzymes BamHI, EcoRI, HindIII, PstI, and SalI, a fine physical map covering about 9.4% of A364a chromosome V (which was estimated as 620kb) was constructed. Further colony hybridization with boundary clones will enable us to "walk" throughout the whole chromosome.

Channel selection of atmospheric remote sensing

We introduce a channel selection method for atmospheric remote-sensing problems described by a Fredholm integral equation of the first kind. Whether one set of channels (CH) is more suitable than another (CH') can be judged by whether (1) the degree of predominance (DP) value of CH is larger than that of CH', i.e., if the number of channels is the same and (2) the number of channels of CH is more than that of CH', if the DP values of both are acceptable. One can calculate the DP of the unknown function f (y) for a set of remote-sensing channels by DP = [1 + (Rf̃(a)(2) - 1) R(d)(2)](-1/2), Rf̃(a)(2) = R(c)(2)[ R(b)(2) + R(a)(2)(1 + R(b)(2))], where R(a), R(b), R(c), and (1 - R(d)(2))(1/2) of this channel set represent the influences on the ability to recover the unknown function caused by various measurement errors, the noise parameter, the relativity of the kernel functions, and the blindness of remote sensing means, respectively. Our channel selection method can be simplified to a conventional method when there are no differences in the relative measurement errors, no blind components of the unknown function and no noise parameters in the kernel function.