Impact of long COVID-19 on posttraumatic stress disorder as modified by health literacy: an observational study in Vietnam.

BACKGROUND: The prevalence of posttraumatic stress disorder (PTSD) has increased, particularly among individuals who have recovered from coronavirus disease 2019 (COVID-19) infection. Health literacy is considered a "social vaccine" that helps people respond effectively to the pandemic. We aimed to investigate the association between long COVID-19 and PTSD, and to examine the modifying role of health literacy in this association. METHODS: A cross-sectional study was conducted at 18 hospitals and health centers in Vietnam from December 2021 to October 2022. We recruited 4,463 individuals who had recovered from COVID-19 infection for at least 4 weeks. Participants provided information about their sociodemographics, clinical parameters, health-related behaviors, health literacy (using the 12-item short-form health literacy scale), long COVID-19 symptoms and PTSD (Impact Event Scale-Revised score of 33 or higher). Logistic regression models were used to examine associations and interactions. RESULTS: Out of the study sample, 55.9% had long COVID-19 symptoms, and 49.6% had PTSD. Individuals with long COVID-19 symptoms had a higher likelihood of PTSD (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.63-2.12; p<0.001). Higher health literacy was associated with a lower likelihood of PTSD (OR, 0.98; 95% CI, 0.97-0.99; p=0.001). Compared to those without long COVID-19 symptoms and the lowest health literacy score, those with long COVID-19 symptoms and a 1-point health literacy increment had a 3% lower likelihood of PTSD (OR, 0.97; 95% CI, 0.96-0.99; p=0.001). CONCLUSION: Health literacy was found to be a protective factor against PTSD and modified the negative impact of long COVID-19 symptoms on PTSD.

Pre-diagnostic circulating resistin concentrations and mortality among individuals with colorectal cancer: Results from the European Prospective Investigation into Cancer and Nutrition study.

Resistin is a protein involved in inflammation and angiogenesis processes and may play a role in the progression of colorectal cancer (CRC). However, it remains unclear whether resistin is associated with increased mortality after CRC diagnosis. We examined pre-diagnostic serum resistin concentrations in relation to CRC-specific and all-cause mortality among 1343 incident CRC cases from the European Prospective Investigation into Cancer and Nutrition cohort. For CRC-specific mortality as the primary outcome, hazard ratios (HRs) and 95% confidence intervals (95% CI) were estimated from competing risk analyses based on cause-specific Cox proportional hazards models and further in sensitivity analyses using Fine-Gray proportional subdistribution hazards models. For all-cause mortality as the secondary outcome, Cox proportional hazards models were used. Subgroup analyses were performed by sex, tumor subsite, tumor stage, body mass index and time to CRC diagnosis. Resistin was measured on a median of 4.8 years before CRC diagnosis. During a median follow-up of 8.2 years, 474 deaths from CRC and 147 deaths from other causes were observed. Resistin concentrations were not associated with CRC-specific mortality (HRQ4vsQ1 = 0.95, 95% CI: 0.73-1.23; Ptrend = .97; and HRper doubling of resistin concentration = 1.00; 95% CI: 0.84-1.19; P = .98) or all-cause mortality. Results from competing risk (sensitivity) analysis were similar. No associations were found in any subgroup analyses. These findings suggest no association between pre-diagnostic circulating resistin concentrations and CRC-specific or all-cause mortality among persons with CRC, and the potential insignificance of resistin in CRC progression.

Prospective and Mendelian randomization analyses on the association of circulating fatty acid binding protein 4 (FABP-4) and risk of colorectal cancer.

BACKGROUND: Fatty acid binding protein 4 (FABP-4) is a lipid-binding adipokine upregulated in obesity, which may facilitate fatty acid supply for tumor growth and promote insulin resistance and inflammation and may thus play a role in colorectal cancer (CRC) development. We aimed to investigate the association between circulating FABP-4 and CRC and to assess potential causality using a Mendelian randomization (MR) approach. METHODS: The association between pre-diagnostic plasma measurements of FABP-4 and CRC risk was investigated in a nested case-control study in 1324 CRC cases and the same number of matched controls within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A two-sample Mendelian randomization study was conducted based on three genetic variants (1 cis, 2 trans) associated with circulating FABP-4 identified in a published genome-wide association study (discovery n = 20,436) and data from 58,131 CRC cases and 67,347 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry. RESULTS: In conditional logistic regression models adjusted for potential confounders including body size, the estimated relative risk, RR (95% confidence interval, CI) per one standard deviation, SD (8.9 ng/mL) higher FABP-4 concentration was 1.01 (0.92, 1.12) overall, 0.95 (0.80, 1.13) in men and 1.09 (0.95, 1.25) in women. Genetically determined higher FABP-4 was not associated with colorectal cancer risk (RR per FABP-4 SD was 1.10 (0.95, 1.27) overall, 1.03 (0.84, 1.26) in men and 1.21 (0.98, 1.48) in women). However, in a cis-MR approach, a statistically significant association was observed in women (RR 1.56, 1.09, 2.23) but not overall (RR 1.23, 0.97, 1.57) or in men (0.99, 0.71, 1.37). CONCLUSIONS: Taken together, these analyses provide no support for a causal role of circulating FABP-4 in the development of CRC, although the cis-MR provides some evidence for a positive association in women, which may deserve to be investigated further.

Genetically determined circulating resistin concentrations and risk of colorectal cancer: a two-sample Mendelian randomization study.

PURPOSE: Resistin, a novel pro-inflammatory protein implicated in inflammatory processes, has been suggested to play a role in colorectal development. However, evidence from observational studies has been inconsistent. Mendelian randomization may be a complementary method to examine this association. METHODS: We conducted a two-sample Mendelian randomization to estimate the association between genetically determined circulating resistin concentrations and risk of colorectal cancer (CRC). Protein quantitative trait loci (pQTLs) from the SCALLOP consortium were used as instrumental variables (IVs) for resistin. CRC genetic summary data was obtained from GECCO/CORECT/CCFR (the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry), and FinnGen (Finland Biobank). The inverse variance weighted method (IVW) was applied in the main analysis, and other robust methods were used as sensitivity analyses. Estimates for the association from the two data sources were then pooled using a meta-analysis approach. RESULTS: Thirteen pQTLs were identified as IVs explaining together 7.80% of interindividual variation in circulating resistin concentrations. Based on MR analyses, genetically determined circulating resistin concentrations were not associated with incident CRC (pooled-IVW-OR per standard deviation of resistin, 1.01; 95% CI 0.96, 1.06; p = 0.67. Restricting the analyses to using IVs within or proximal to the resistin-encoding gene (cis-IVs), or to IVs located elsewhere in the genome (trans-IVs) provided similar results. The association was not altered when stratified by sex or CRC subsites. CONCLUSIONS: We found no evidence of a relationship between genetically determined circulating resistin concentrations and risk of CRC.

Prevalence of exclusive breastfeeding for the first six months of an infant's life and associated factors in a low-middle income country.

BACKGROUND: Although breastfeeding is practiced by 98% of mothers in Vietnam, infant breastfeeding behaviors remain far from World Health Organization recommendations and continues to decline. This study aims to explore the prevalence and factors associated with exclusive breastfeeding in the first six months of an infant's life. METHODS: A cross-sectional study utilized a self-administered maternal questionnaire to collect data on 1072 Vietnamese mothers who brought infants aged between 6 and 30 months to a community health centre (CHC) for routine vaccination. Data collection was conducted from March to May 2021 in two cities in Central and North Vietnam. In order to measure exclusive breastfeeding, we asked mothers to recall (yes / no), if the child had received breast milk, formula, colostrum milk powder, water, vitamin / medicine, fruit juice / honey, and complementary foods aged under six months. RESULTS: In the first six months, 14.2% of mothers exclusively breastfed their infants. Multivariable logistic regression analysis demonstrated a significant association between exclusive infant breastfeeding and the highest maternal education level (university or postgraduate) (adjusted odds ratio (aOR) 2.55; 95% confidence interval (CI) 1.10, 5.91); male infants (aOR 1.72; 95% CI 1.11, 2.68); duration of skin-to-skin contact greater than 90 min (aOR 7.69; 95% CI 1.95, 30.38); receiving first breastfeeding during skin-to-skin contact (aOR 2.31; 95% CI 1.30, 4.10); completely feeding infant directly at the breast (aOR 1.65; 95% CI 1.00, 2.71) and exclusive breastfeeding intention during pregnancy (aOR 2.48; 95% CI 1.53, 4.00). When compared with mothers who were prenatally exposed to infant formula advertising classified as "often", the prevalence of exclusive infant breastfeeding was higher in mothers who classified their prenatal exposure to infant formula advertising as "sometimes" (aOR 2.15; 95% CI 1.13, 4.10), and "seldom" (aOR 2.58; 95% CI 1.25, 5.36). CONCLUSION: The prevalence of mothers who practiced exclusive infant breastfeeding during the first six months in Vietnam was low. Infants should receive early maternal-infant skin-to-skin contact greater than 90 min and complete first breastfeeding during skin-to-skin contact. Further, mothers should be protected against infant formula advertisements to maximise the likelihood of exclusive breastfeeding during the child's infancy.

Pre-Diagnostic Circulating Resistin Concentrations Are Not Associated with Colorectal Cancer Risk in the European Prospective Investigation into Cancer and Nutrition Study.

Resistin is a polypeptide implicated in inflammatory processes, and as such could be linked to colorectal carcinogenesis. In case-control studies, higher resistin levels have been found in colorectal cancer (CRC) patients compared to healthy individuals. However, evidence for the association between pre-diagnostic resistin and CRC risk is scarce. We investigated pre-diagnostic resistin concentrations and CRC risk within the European Prospective Investigation into Cancer and Nutrition using a nested case-control study among 1293 incident CRC-diagnosed cases and 1293 incidence density-matched controls. Conditional logistic regression models controlled for matching factors (age, sex, study center, fasting status, and women-related factors in women) and potential confounders (education, dietary and lifestyle factors, body mass index (BMI), BMI-adjusted waist circumference residuals) were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for CRC. Higher circulating resistin concentrations were not associated with CRC (RR per doubling resistin, 1.11; 95% CI 0.94-1.30; p = 0.22). There were also no associations with CRC subgroups defined by tumor subsite or sex. However, resistin was marginally associated with a higher CRC risk among participants followed-up maximally two years, but not among those followed-up after more than two years. We observed no substantial correlation between baseline circulating resistin concentrations and adiposity measures (BMI, waist circumference), adipokines (adiponectin, leptin), or metabolic and inflammatory biomarkers (C-reactive protein, C-peptide, high-density lipoprotein cholesterol, reactive oxygen metabolites) among controls. In this large-scale prospective cohort, there was little evidence of an association between baseline circulating resistin concentrations and CRC risk in European men and women.

Prevalence of early skin-to-skin contact and its impact on exclusive breastfeeding during the maternity hospitalization.

BACKGROUND: Early essential newborn care has been implemented in countries regardless high or low neonatal mortality. This study aims to investigate the current practice of skin-to-skin contact (SSC) and its effect on exclusive breastfeeding during the hospital stay. METHODS: This is a cross-sectional study of 1812 Vietnamese mothers in multicenter. A questionnaire answered by the mothers was used to assess the duration of both SSC and breastfeeding practices. Multivariable logistic regression was used to identify a dose-response relationship between early SSC and prevalence of exclusive breastfeeding in hospital. RESULTS: There were 88.7% of mothers experiencing SSC with their infants right after birth and the highest prevalence of SSC was found in district hospitals. Among those experiencing SSC, 18.8% of the infants received more than 90 min of SSC and completed the first breastfeeding during SSC time. Prevalence of exclusive breastfeeding during maternity hospital stay was 46.7%. We found a significant dose-response relation between the duration of SSC and exclusive breastfeeding in hospital. Compared with infants without SSC, the prevalence of exclusive breastfeeding was higher in infants who experienced SSC for 15-90 min (adjusted odds ratio [aOR], 95% confidence interval [95%-CI]: 2.62 [1.61-4.27]) and more than 90 min (aOR [95%-CI]: 5.98 [3.48-10.28]). Completed first breastfeeding during SSC time (aOR [95%-CI]: 4.24 [3.28-5.47]) and being born in district hospitals (aOR [95%-CI]: 2.35 [1.79-3.09]) were associated with increased prevalence of exclusive breastfeeding during hospital stay. On the other hand, mother education level as high school/intermediate (aOR [95%-CI]: 0.58 [0.42-0.82]) and place of residence classified as rural decreased odds of exclusive breastfeeding in hospital (aOR [95%-CI]: 0.78 [0.61-0.99]). CONCLUSION: Our results demonstrate a strong dose-response relationship between duration of SSC and exclusive breastfeeding in hospital. Interventions that support exclusive breastfeeding during hospital stay, especially achieving prolonged uninterrupted SSC, could improve the duration of breastfeeding.

Gynecological cancer and omega-3 fatty acid intakes: Meta-analysis.

BACKGROUND AND OBJECTIVES: Previous observational epidemiological studies have reported inconsistent findings on the association between dietary intake of omega-3 fatty acids and endocrine-related gynecological cancer including ovarian cancer and endometrial cancer. This study aimed to investigate this association using a metaanalysis of observational studies. METHODS AND STUDY DESIGN: We searched PubMed, EMBASE, and Cochrane library by using keywords related to the topic in December 2019. The pooled odd ratios (pORs), pooled relative risks (pRRs), or pooled hazard ratios (pHRs) with 95% confidence intervals (CIs) were calculated based on a random- effects model. Also, we performed subgroup analyses by methodological quality, type of cancer, study design, and type of omega-3 fatty acids. RESULTS: A total of 10 observational studies with six case-control and four prospective cohort studies were included in the current meta-analysis. In the meta-analysis of all studies, dietary intake of omega-3 fatty acids was not significantly associated with the risk of endometrial and ovarian cancers (pOR/HR, 0.87; 95% CI, 0.73-1.04; I2=67.2%) (highest versus lowest intake). In the subgroup analysis by type of study, no significant association was found in cohort studies (pHR, 1.03; 95% CI, 0.63-1.67, I2=81.9%), whereas dietary intake of omega-3 fatty acids was associated with the decreased risk of endocrine-related gynecological cancers in case-control studies (pOR, 0.81; 95% CI, 0.67 to 0.98, I2=55.7%). CONCLUSIONS: The current metaanalysis of observational studies suggests that dietary intake of omega-3 fatty acids is not significantly associated with the risk of endocrine-related gynecological cancer.

Comparative Efficacy of Targeted Therapies in Patients with Non-Small Cell Lung Cancer: A Network Meta-Analysis of Clinical Trials.

This study aims to investigate the efficacy of targeted therapies in the treatment of non-small cell lung cancer (NSCLC) by using a network meta-analysis of clinical trials. PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched by using keywords related to the topic on 19 September 2018. Two investigators independently selected relevant trials by pre-determined criteria. A pooled response ratio (RR) for overall response rate (ORR) and a hazard ratio (HR) for progression-free survival (PFS) were calculated based on both the Bayesian and frequentist approaches. A total of 128 clinical trials with 39,501 participants were included in the final analysis of 14 therapeutic groups. Compared with chemotherapy, both ORR and PFS were significantly improved for afatinib, alectinib, and crizotinib, while only PFS was significantly improved for cabozantinib, ceritinib, gefitinib, and osimertinib. Consistency was observed between the direct and indirect comparisons based on the Bayesian approach statistically and the frequentist approach visually. Cabozantinib and alectinib showed the highest probability for the first-line treatment ranking in ORR (62.5%) and PFS (87.5%), respectively. The current network meta-analysis showed the comprehensive evidence-based comparative efficacy of different types of targeted therapies, which would help clinicians use targeted therapies in clinical practice.

Efficacy of Crizotinib, Ceritinib, and Alectinib in ALK-Positive Non-Small Cell Lung Cancer Treatment: A Meta-Analysis of Clinical Trials.

This study aimed to evaluate the efficacy of anaplastic lymphoma kinase (ALK)-inhibitors in the treatment of ALK-positive non-small cell lung cancer (NSCLC) by using a meta-analysis of clinical trials. We searched PubMed, EMBASE, Cochrane Library, and Clinicaltrials.gov by using keywords related to the topic in August 2018. The pooled effect sizes were calculated based on a random-effects model. We also performed subgroup meta-analysis by types of ALK inhibitors (crizotinib, ceritinib, and alectinib). A total of 20 clinical trials with 10 single-arm trials and 10 double-arm trials were included in the final meta-analysis. The median overall survival (OS), progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR), 1 year survival rate, and 2 year survival rate were 19.14 months, 8.47 months, 62%, 78%, 74%, and 62%, respectively. ALK inhibitors showed a significantly superior efficacy compared with chemotherapy (hazard ratio (HR) for OS, 0.83; HR for PFS, 0.43; rate difference (RD) for ORR, 0.23; and RD for DCR, 0.10). The current meta-analysis of clinical trials showed the significant efficacy of ALK inhibitors in the treatment of ALK-positive NSCLC. Further head-to-head trials are needed to compare their efficacy with other types of NSCLC treatment regimens. PROSPERO registration: CRD42018085987.

Night-shift work and risk of breast cancer in Korean women.

PURPOSE: This study evaluated the association between night-shift work (NSW) and breast cancer risk as well as subtypes of breast cancer in Korean women. PATIENTS AND METHODS: The study population included 1721 female breast cancer cases and 1721 female controls matched by age. The subtypes of breast cancer were determined based on estrogen, progesterone, and human epidermal growth factor receptor 2 statuses by reviewing pathology reports. Odds ratios (ORs) for NSW experience, age at commencement of NSW, frequency, and duration were estimated using conditional logistic regression and were adjusted for confounders such as parity and socioeconomic status-related factors. RESULTS: Among 1721 pairs, 10.58% of cases and 9.59% of controls had ever engaged in NSW. NSW was not associated with breast cancer risk in terms of ever having night-shift exposure (adjusted OR was 1.11, 95% confidence interval [CI] =0.89-1.40), duration, frequency, or cumulative working time. The OR for >10 years of lifetime duration of NSW was 1.55 (95% CI 0.89-2.69, P=0.124). In addition, the OR for >35,000 hrs for cumulative frequency of night work was OR=1.42 (95% CI=0.73-2.74, P=0.304). There was no heterogeneity in ORs of ever having NSW and cumulative duration of NSW between four subtypes of breast cancer. CONCLUSION: NSW including long-term and heavy working exposure was not associated with breast cancer risk.

Night-shift work, circadian and melatonin pathway related genes and their interaction on breast cancer risk: evidence from a case-control study in Korean women.

Our purpose is to investigate the impact of circadian and melatonin pathway genes as well as their interactions with night-shift work (NSW) on breast cancer risk in Korean women. Information about NSW and other covariates was collected using a structured questionnaire and twenty-two polymorphisms in 11 genes were analyzed in a hospital-based case-control study with 941 cases of breast cancer and 959 controls. In analysis of the main effects of each single nucleotide polymorphisms(SNPs), variants in CLOCK rs11133373 was associated with breast cancer risk even after false discovery rate (FDR) correction (Odd Ratios (OR) = 1.38 (95% Confident Interval (CI) 1.14-1.69) in CG and CC compared to GG genotype. Analysis of MTNR1A rs2119882 demonstrated a decreased risk of breast cancer in CC compared to TT (p-FDR = 0.043). A correlation between NSW and breast cancer interaction was found in two loci. NSW increased risk of breast cancer in women who carried the heterozygote genotype of CRY2 rs2292912 (OR = 1.98, 95% CI = 1.14-3.44) or carried at least one minor allele of RORA rs1482057 (OR = 2.20, 95% CI = 1.10-4.37). Our study results support a putative role for several loci of circadian genes and genes of melatonin biosynthesis and their interaction, and the gene interactions with NSW in the development of breast cancer.

Alcohol use disorder and health-related quality of life in Korean night-shift workers: A cross-sectional study using the KNHANES 2007-2015 data.

This study aimed to evaluate the prevalence of night-shift work, and the association of night-shift work with alcohol use disorders(AUDs), as well as with health-related quality of life(HRQL), in Korean adult workers. A total of 26,895 adult workers aged 20-59 years were included in the analysis. AUDs were assessed using the Alcohol Use Disorders Identification Test(AUDIT), and HRQL was measured by the EuroQol-5D questionnaire with five main dimensions. We found an interaction effect between gender and working status on AUDs (p = 0.0065), suggesting that women are more fragile than men in terms of the effects of night work but not regarding HRQL (p = 0.1729). Female night workers had higher risk of AUDs than female day workers (odds ratio(OR): 2.23, 95% confidence interval (CI): 1.48-3.38) but this effect was not noted in male night workers (OR: 0.97, 95% CI: 0.69-1.37). Lower HRQL was found in depression dimension for night workers compared to day workers (OR: 1.37, 95% CI: 1.00-1.89), whereas day-night regular shift workers were protected from depression. Risk of AUDs and lower HRQL were identified in female night workers but not in male night workers. This association suggests that women are more fragile than men in terms of the effects of night work.

Dietary Intake of Omega-3 fatty acids and Endocrine-related Gynecological Cancer: A Meta-Analysis of Observational Studies.

PURPOSE: Previous observational epidemiological studies have reported inconsistent findings on the association between dietary intake of omega-3 fatty acids and endocrine-related gynecological cancer such as ovarian cancer and endometrial cancer. This study aimed to investigate this association using a meta-analysis of observational studies. MATERIALS AND METHODS: We searched PubMed, EMBASE, and Cochrane library by using key words related with the topic in April 2017. The pooled odd ratios (pORs), relative risks (pRRs), or hazard ratios (pHRs) with 95% confidence intervals (CIs) were calculated based on the random-effects model. Also, we performed subgroup meta-analysis by methodological quality, types of cancer, study design, and omega-3 fatty acids. RESULTS: A total of ten observational studies with six case-control and four cohort studies were included in the final meta-analysis. In the meta-analysis of all the studies, dietary intake of total omega-3 fatty acids was not significantly associated with the risk of endometrial and ovarian cancers (pOR/HR, 0.87; 95% CI, 0.73-1.04; I2=67.2%) (highest versus lowest intake). In the subgroup meta-analysis by type of study, there was no significant association between them in cohort studies (pHR, 1.03; 95% CI, 0.63-1.67, I2=81.9%), whereas its reduced risk was observed in case-control studies (pOR, 0.81; 95% CI, 0.67 to 0.98, I2=55.7%). CONCLUSION: The current meta-analysis of observational studies suggests that there is no higher level of evidence to support the protective effect of dietary omega-3 fatty acids on endocrine-related gynecological cancer. Further prospective studies should be conducted to confirm the association.

Function of the evolutionarily conserved plant methionine-S-sulfoxide reductase without the catalytic residue.

In plants, two types of methionine sulfoxide reductase (MSR) exist, namely methionine-S-sulfoxide reductase (MSRA) and methionine-R-sulfoxide reductase (MSRB). These enzymes catalyze the reduction of methionine sulfoxides (MetO) back to methionine (Met) by a catalytic cysteine (Cys) and one or two resolving Cys residues. Interestingly, a group of MSRA encoded by plant genomes does not have a catalytic residue. We asked that if this group of MSRA did not have any function (as fitness), why it was not lost during the evolutionary process. To challenge this question, we analyzed the gene family encoding MSRA in soybean (GmMSRAs). We found seven genes encoding GmMSRAs, which included three segmental duplicated pairs. Among them, a pair of duplicated genes, namely GmMSRA1 and GmMSRA6, was without a catalytic Cys residue. Pseudogenes were ruled out as their transcripts were detected in various tissues and their Ka/Ks ratio indicated a negative selection pressure. In vivo analysis in Δ3MSR yeast strain indicated that the GmMSRA6 did not have activity toward MetO, contrasting to GmMSRA3 which had catalytic Cys and had activity. When exposed to H2O2-induced oxidative stress, GmMSRA6 did not confer any protection to the Δ3MSR yeast strain. Overexpression of GmMSRA6 in Arabidopsis thaliana did not alter the plant's phenotype under physiological conditions. However, the transgenic plants exhibited slightly higher sensitivity toward salinity-induced stress. Taken together, this data suggested that the plant MSRAs without the catalytic Cys are not enzymatically active and their existence may be explained by a role in regulating plant MSR activity via dominant-negative substrate competition mechanism.

RiceArrayNet: a database for correlating gene expression from transcriptome profiling, and its application to the analysis of coexpressed genes in rice.

Microarray data can be used to derive understanding of the relationships between the genes involved in various biological systems of an organism, given the availability of databases of gene expression measurements from the complete spectrum of experimental conditions and materials. However, there have been no reports, to date, of such a database being constructed for rice (Oryza sativa). Here, we describe the construction of such a database, called RiceArrayNet (RAN; http://www.ggbio.com/arraynet/), which provides information on coexpression between genes in terms of correlation coefficients (r values). The average number of coexpressed genes is 214, with sd of 440 at r >or= 0.5. Given the correlation between genes in a gene pair, the degrees of closeness between genes can be visualized in a relational tree and a relational network. The distribution of correlated genes according to degree of stringency shows how each gene is related to other genes. As an application of RAN, the 16-member L7Ae ribosomal protein family was explored for coexpressed genes and gene expression values within and between rice and Arabidopsis (Arabidopsis thaliana), and common and unique features in coexpression partners and expression patterns were observed for these family members. We observed a correlation pattern between Os01g0968800, a drought-responsive element-binding transcription factor, Os02g0790500, a trehalose-6-phosphate synthase, and Os06g0219500, a small heat shock factor, reflecting the fact that genes responding to the same biological stresses are regulated together. The RAN database can be used as a tool to gain insight into a particular gene by examining its coexpression partners.