Single cell transcriptomics reveals dysregulated cellular and molecular networks in a fragile X syndrome model.

Despite advances in understanding the pathophysiology of Fragile X syndrome (FXS), its molecular basis is still poorly understood. Whole brain tissue expression profiles have proved surprisingly uninformative, therefore we applied single cell RNA sequencing to profile an FMRP deficient mouse model with higher resolution. We found that the absence of FMRP results in highly cell type specific gene expression changes that are strongest among specific neuronal types, where FMRP-bound mRNAs were prominently downregulated. Metabolic pathways including translation and respiration are significantly upregulated across most cell types with the notable exception of excitatory neurons. These effects point to a potential difference in the activity of mTOR pathways, and together with other dysregulated pathways, suggest an excitatory-inhibitory imbalance in the Fmr1-knock out cortex that is exacerbated by astrocytes. Our data demonstrate that FMRP loss affects abundance of key cellular communication genes that potentially affect neuronal synapses and provide a resource for interrogating the biological basis of this disorder.

Comparative analysis of short- and long-term outcomes in laparoscopic versus open surgery for colorectal cancer patients undergoing hemodialysis.

PURPOSE: Although minimally invasive colorectal surgery has been proven to have a shorter hospital stay and fewer short-term complications than open surgery, the advantages of laparoscopic surgery for colorectal cancer patients undergoing hemodialysis have not been validated. This study compared the outcomes of open and laparoscopic approaches in these patients. MATERIALS AND METHODS: Between January 2007 and December 2020, we retrospectively analyzed the clinical data of 78 hemodialysis patients who underwent curative-intent, elective colorectal surgery. Patients were divided into two groups according to the surgical method: open and laparoscopic. RESULTS: Postoperative morbidity (p = 0.480) and mortality (p = 0.598) rates and length of hospital stay (28.8 vs. 27.5 days, p = 0.830) were similar between the groups. However, laparoscopic surgery patients had a shorter return to clear liquid, full liquid, or soft food time than open surgery patients (p < 0.001, p = 0.007, and p = 0.002, respectively). Disease-free survival and long-term cancer-specific survival rates were also similar between the two groups (p = 0.353 and p = 0.201, respectively). Multivariate analysis revealed that intraoperative blood transfusion was a risk factor for severe complications and mortality (OR 6.055; p = 0.046), and the odds ratio (OR) of laparoscopic surgery was not significantly greater than that of open surgery (OR = 0.537, p = 0.337). CONCLUSION: Although laparoscopic surgery did not result in hemodialysis patients having a shorter postoperative hospital stay, our results suggest that the laparoscopic approach is as safe as open surgery for hemodialysis patients and may be beneficial for shortening the return time to food intake.

Predictors for temporary stomas non-closure among non-metastatic rectal cancer patients undergoing curative resection: a retrospective analysis.

BACKGROUND: The primary treatment for non-metastatic rectal cancer is curative resection. However, sphincter-preserving surgery may lead to complications. This study aims to develop a predictive model for stoma non-closure in rectal cancer patients who underwent curative-intent low anterior resection. METHODS: Consecutive patients diagnosed with non-metastatic rectal cancer between January 2005 and December 2017, who underwent low anterior resection, were retrospectively included in the Chang Gung Memorial Foundation Institutional Review Board. A comprehensive evaluation and analysis of potential risk factors linked to stoma non-closure were performed. RESULTS: Out of 956 patients with temporary stomas, 10.3% (n = 103) experienced non-closure primarily due to cancer recurrence and anastomosis-related issues. Through multivariate analysis, several preoperative risk factors significantly associated with stoma non-closure were identified, including advanced age, anastomotic leakage, positive nodal status, high preoperative CEA levels, lower rectal cancer presence, margin involvement, and an eGFR below 30 mL/min/1.73m2. A risk assessment model achieved an AUC of 0.724, with a cutoff of 2.5, 84.5% sensitivity, and 51.4% specificity. Importantly, the non-closure rate could rise to 16.6% when more than two risk factors were present, starkly contrasting the 3.7% non-closure rate observed in cases with a risk score of 2 or below (p < 0.001). CONCLUSION: Prognostic risk factors associated with the non-closure of a temporary stoma include advanced age, symptomatic anastomotic leakage, nodal status, high CEA levels, margin involvement, and an eGFR below 30 mL/min/1.73m2. Hence, it is crucial for surgeons to evaluate these factors and provide patients with a comprehensive prognosis before undergoing surgical intervention.

Upfront primary tumor resection versus upfront systemic therapy for metastatic colorectal cancer: a systematic review and meta-analysis.

PURPOSE: The standard initial treatment for metastatic colorectal cancer (mCRC) remains debated. This study investigated whether upfront primary tumor resection (PTR) or upfront systemic therapy (ST) provides better survival outcomes for patients with mCRC. METHODS: The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched for studies published at any time from January 1, 2004, to December 31, 2022. Randomized controlled trials (RCTs) and prospective or retrospective cohort studies (RCSs) utilizing propensity score matching (PSM) or inverse probability treatment weighting (IPTW) were included. We evaluated overall survival (OS) and short-term (60-day) mortality in these studies. RESULTS: After reviewing 3,626 articles, we identified 10 studies including a total of 48,696 patients. OS differed significantly between the upfront PTR and upfront ST arms (hazard ratio [HR] 0.62; 95% CI: 0.57-0.68; p < 0.001). However, a subgroup analysis identified no significant difference in OS in RCTs (HR 0.97; 95% CI: 0.7-1.34; p = 0.83), whereas significant difference in OS occurred between the treatment arms in RCSs with PSM or IPTW (HR 0.59; 95% CI: 0.54-0.64; p < 0.001). Short-term mortality was analyzed in three RCTs, and 60-day mortality differed significantly between the treatment arms (risk ratio [RR] 3.52; 95% CI: 1.23-10.10; p = 0.02). CONCLUSIONS: In RCTs, upfront PTR for mCRC did not improve OS and enhanced the risk of 60-day mortality. However, upfront PTR seemed to increase OS in RCSs with PSM or IPTW. Therefore, whether upfront PTR should be used for mCRC remains unclear. Further large RCTs are required.

Comparison of clinical outcomes of stoma reversal during versus after chemotherapy for rectal cancer patients.

PURPOSE: The optimal timing of stoma closure during or after adjuvant chemotherapy for rectal cancer patients undergoing sphincter-preserving surgery remains unknown. This study aimed to investigate the influence of clinical and oncological outcomes depending on the timing of stoma closure. METHODS: Between January 2006 and December 2015, we enrolled 244 consecutive rectal cancer patients who underwent curative-intent sphincter-preserving surgery with diverting transverse colostomy and adjuvant chemotherapy. Patients with stoma closure during (During group) adjuvant chemotherapy were compared to those who had stoma closure after adjuvant chemotherapy (After group). RESULTS: Parastomal hernia occurred more frequently in the after group than in the during group. (10% vs. 2.9%, p = 0.028). Overall, no significant difference was observed in overall survival (OS) or disease-free survival (DFS) between the two groups (p = 0.911 for OS, p = 0.505 for DFS). However, an inferior OS occurred if reopen surgery was performed within 30 days of stoma closure in the during group, as compared with the after group (p = 0.004). In addition, a marginally poor DFS was observed in the group of patients who received further operations due to 30-day stoma closure complications compared to the other patients (p = 0.07). CONCLUSIONS: For rectal cancer patients who underwent sphincter-preserving surgery, attention should be given to avoid 30-day major complications after stoma reversal because patients who require reoperation during adjuvant chemotherapy may have poor long-term survival.

FMRP links optimal codons to mRNA stability in neurons.

Fragile X syndrome (FXS) is caused by inactivation of the FMR1 gene and loss of encoded FMRP, an RNA binding protein that represses translation of some of its target transcripts. Here we use ribosome profiling and RNA sequencing to investigate the dysregulation of translation in the mouse brain cortex. We find that most changes in ribosome occupancy on hundreds of mRNAs are largely driven by dysregulation in transcript abundance. Many down-regulated mRNAs, which are mostly responsible for neuronal and synaptic functions, are highly enriched for FMRP binding targets. RNA metabolic labeling demonstrates that, in FMRP-deficient cortical neurons, mRNA down-regulation is caused by elevated degradation and is correlated with codon optimality. Moreover, FMRP preferentially binds mRNAs with optimal codons, suggesting that it stabilizes such transcripts through direct interactions via the translational machinery. Finally, we show that the paradigm of genetic rescue of FXS-like phenotypes in FMRP-deficient mice by deletion of the Cpeb1 gene is mediated by restoration of steady-state RNA levels and consequent rebalancing of translational homeostasis. Our data establish an essential role of FMRP in codon optimality-dependent mRNA stability as an important factor in FXS.

Phthalate levels in prenatal and postnatal bedroom dust in the SELMA study.

Phthalates are common in polyvinyl chloride (PVC) plastics and numerous consumer goods in our homes from which they can migrate and adhere to indoor dust particles. It is known that indoor dust exposure contribute to human phthalate intake; however, there is a lack of large studies with a repeated-measure design investigating how phthalate levels in indoor dust may vary over time in people's homes. This study investigated levels of seven phthalates and one alternative plasticiser di-iso-nonyl-cyclohexane-di-carboxylate (DiNCH) in bedroom dust collected prenatally around week 25 during pregnancy and postnatally at six months after birth, from 496 Swedish homes. Prenatal and postnatal phthalate levels were compared using correlation and season-adjusted general linear regression models. Over the nine-month period, levels of six out of seven phthalates were associated as indicated by a positive Pearson correlation (0.18 < r < 0.50, P < .001) and Lin's concordance correlation between matched prenatal and postnatal dust samples. Compared to prenatal levels, the season-adjusted postnatal levels decreased for five phthalates, whilst di-ethyl-hexyl phthalate (DEHP), di-2-propylheptyl phthalate (DPHP) and DiNCH increased. The results suggest that families with higher phthalate levels in bedroom dust during pregnancy are likely to remain among those with higher levels in the infancy period. However, all average phthalate levels changed over this specific nine-month period suggesting that available phthalate sources or their use were altered between the dust collections. Changes in home characteristics, family lifestyle, and phthalate replacement trends may contribute to explain the differences.

Preoperative risk stratification of permanent stoma in patients with non-metastatic mid and low rectal cancer undergoing curative resection and a temporary stoma.

BACKGROUND: Although a temporary stoma can mitigate the severity of anastomotic leakage, some rectal cancer patients retain a permanent stoma after sphincter-preserving surgery. Therefore, this study aimed to identify independent preoperative risk factors for permanent stoma and establish a prediction model for mid-and low-rectal cancer patients who underwent sphincter-preserving surgery and temporary stoma. METHODS: We retrospectively reviewed consecutive patients with non-metastatic rectal cancer between 2000 and 2015. The risk factors for permanent stomas were collected and analyzed. RESULTS: A total of 1020 rectal cancer patients with temporary stoma were included. The overall rate of permanent stoma was 17.5% (n = 179). Cancer progression and anastomotic complications are major causes of permanent stomas. Multivariate analysis showed that preoperative risk factors such as advanced age, male sex, preoperative CEA ≥ 10 ng/ml, T4 stage, N stage, low rectal tumor, and ASA ≥ III were independent preoperative risk factors after adjustment. The ROC curve of the risk factors and permanent stoma showed an AUC of 0.689, a cut-off value of 2.5, a sensitivity of 0.689, and a specificity of 0.622. The permanent stoma rates were significantly higher between risk scores ≤ 2 and > 2 (29.9% vs. 11.3%, p < 0.001). CONCLUSION: Preoperative CEA ≥ 10 ng/ml, T4 stage, N stage, low rectal tumor, advanced age, ASA ≥ III, and male sex were independent preoperative prognostic factors for a permanent stoma. The risk was higher with a score greater than two. Therefore, the risk of subsequent permanent stoma should be evaluated and informed to the patient prior to the primary surgery.

Smoking cessation for less than 10 years remains a risk factor of anastomotic leakage in mid-to-low rectal cancer patients undergoing sphincter-preserving surgery.

PURPOSE: Although cigarette smoking is a well-known risk factor for anastomotic leakage during rectal surgery, the proper duration of smoking cessation that can decrease anastomotic leakage in patients undergoing sphincter-preserving surgery is unclear. This study aimed to investigate the optimal duration of smoking cessation that can reduce this complication. METHODS: Between January 1, 2000, and December 31, 2012, we enrolled 1246 consecutive patients who underwent curative-intent sphincter-preserving surgery without preventive stoma at the Division of Colorectal Surgery of a tertiary referral center in Taiwan. Questionnaires were used to record their pre-surgical smoking status. The receiver operating characteristic (ROC) curve was used to determine the optimal cut-off duration of smoking cessation. Multivariate analysis was used to verify the effect of cigarette cessation on anastomotic leakage. RESULTS: The ROC curve showed a cut-off value of 10.5 years of cessation duration. Therefore, the former-smoker group was further divided using a cessation duration of 10 years. The overall anastomotic leakage rate was 5.29%. However, the anastomotic leakage rate in current smokers (9.3%) and in those who quit for < 10 years (12.9%) was significantly higher than that in non-smokers (3.3%) and those who quit for ≥ 10 years (4.5%). On multivariate analysis, current smokers (p = 0.022), former smokers with < 10 years of smoking cessation (OR 2.725; p = 0.029), male sex (p = 0.015), and low rectal cancer (p < 0.001) were all independently related to the development of anastomotic leakage. CONCLUSION: Smoking cessation for < 10 years remains a risk factor for anastomotic leakage in patients with mid-to-low rectal cancer undergoing sphincter-preserving surgery.

Indoor phthalate exposure and contributions to total intake among pregnant women in the SELMA study.

Phthalates are widely used in consumer products. Exposure to phthalates can lead to adverse health effects in humans, with early-life exposure being of particular concern. Phthalate exposure occurs mainly through ingestion, inhalation, and dermal absorption. However, our understanding of the relative importance of different exposure routes is incomplete. This study estimated the intake of five phthalates from the residential indoor environment for 455 Swedish pregnant women in the SELMA study using phthalate mass fraction in indoor dust and compares these to total daily phthalate intakes back-calculated from phthalate metabolite concentrations in the women's urine. Steady-state models were used to estimate indoor air phthalate concentrations from dust measurements. Intakes from residential dust and air made meaningful contributions to total daily intakes of more volatile di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), and di-iso-butyl phthalate (DiBP) (11% of total DEP intake and 28% of total DnBP and DiBP intake combined). Dermal absorption from air was the dominant pathway contributing to the indoor environmental exposure. Residential exposure to less volatile phthalates made minor contributions to total intake. These results suggest that reducing the presence of low molecular weight phthalates in the residential indoor environment can meaningfully reduce phthalate intake among pregnant women.

Optimization of ribosome profiling using low-input brain tissue from fragile X syndrome model mice.

Dysregulated protein synthesis is a major underlying cause of many neurodevelopmental diseases including fragile X syndrome. In order to capture subtle but biologically significant differences in translation in these disorders, a robust technique is required. One powerful tool to study translational control is ribosome profiling, which is based on deep sequencing of mRNA fragments protected from ribonuclease (RNase) digestion by ribosomes. However, this approach has been mainly applied to rapidly dividing cells where translation is active and large amounts of starting material are readily available. The application of ribosome profiling to low-input brain tissue where translation is modest and gene expression changes between genotypes are expected to be small has not been carefully evaluated. Using hippocampal tissue from wide type and fragile X mental retardation 1 (Fmr1) knockout mice, we show that variable RNase digestion can lead to significant sample batch effects. We also establish GC content and ribosome footprint length as quality control metrics for RNase digestion. We performed RNase titration experiments for low-input samples to identify optimal conditions for this critical step that is often improperly conducted. Our data reveal that optimal RNase digestion is essential to ensure high quality and reproducibility of ribosome profiling for low-input brain tissue.

Effect of Convalescent Plasma Therapy on Viral Shedding and Survival in Patients With Coronavirus Disease 2019.

Currently, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been reported in almost all countries globally. No effective therapy has been documented for COVID-19, and the role of convalescent plasma therapy is unknown. In the current study, 6 patients with COVID-19 and respiratory failure received convalescent plasma a median of 21.5 days after viral shedding was first detected, all tested negative for SARS-CoV-2 RNA within 3 days after infusion, and 5 eventually died. In conclusion, convalescent plasma treatment can end SARS-CoV-2 shedding but cannot reduce the mortality rate in critically ill patients with end-stage COVID-19, and treatment should be initiated earlier.

Maternal serum levels of perfluoroalkyl substances in early pregnancy and offspring birth weight.

BACKGROUND: Perfluoroalkyl substances (PFASs) are widespread, bioaccumulating, and persistent and show placental transfer. Emerging research indicates associations between prenatal exposure and low birth weight. The aim of this study was to assess the associations between first trimester exposure to PFASs and birth weight (BW) in the Swedish Environmental, Longitudinal, Mother and child, Asthma and allergy (SELMA) study and examine whether associations differ between girls and boys. METHODS: Eight PFASs were analyzed in maternal serum (median: 10 weeks of pregnancy). Associations between prenatal PFAS exposure and birth outcomes with BW, BW for gestational age, and birth small for gestational age (SGA) were assessed in 1533 infants, adjusted for potential confounders and stratified by sex. RESULTS: Increased maternal perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) were associated with lower BW, lower BW for gestational age, and SGA birth. Associations were significant only in girls, where prenatal exposure in the upper quartile was associated with a 93-142-g lower BW when compared with that of the lowest quartile exposure. The associations were not mediated by effects on gestational age. CONCLUSIONS: We found associations between prenatal exposure for five different PFASs and birth weight, with more pronounced associations in girls than in boys.

Tofacitinib citrate-based liposomes for effective treatment of rheumatoid arthritis.

Low drug concentrations at interest sites and unwanted systemic side effects are major obstacles to effective therapy of rheumatoid arthritis (RA). With the aim of improving the efficacy of tofacitinib citrate (TOF), a liposomal system was developed for targeted delivery to inflamed joints, and this approach was validated in a RA rat model. TOF was effectively loaded into the liposomes (entrapment efficiency: 86.5±1.9%; drug loading: 2.3±0.05%) by a pH gradient method, and these molecules featured sustained drug release behaviour over 48 h. In vitro and in vivo studies showed that TOF loaded liposomes (TOFL) could be selectively taken up by inflamed cells and showed improved accumulation in arthritic paws, demonstrating the superior target ability to RA tissues. Moreover, compared to free TOF, TOFL significantly improved the therapeutic efficacy, reduced the inflammatory cytokine expression and lipid peroxidation in synovial cells in the joint tissue of RA rats. Overall, these results indicate that TOFL served as the useful nanocarriers for RA-targeted therapy.

Preoperative Carcinoembryonic Antigen as a Poor Prognostic Factor in Stage I-III Colorectal Cancer After Curative-Intent Resection: A Propensity Score Matching Analysis.

BACKGROUND: Preoperative carcinoembryonic antigen (CEA) has yet to be used as a prognostic or adjuvant chemotherapy factor for colorectal cancer (CRC). METHODS: This retrospective cohort study included all stage I-III CRC patients with different preoperative serum CEA levels (≤ 5, 5-10, and > 10 ng/ml) at a single center between 1995 and 2010. Propensity score matching was performed in a 1:1 ratio between the two elevated CEA groups (5-10 ng/ml and > 10 ng/ml) and in a 1:2 ratio between the elevated and non-elevated groups (≤ 5 ng/ml), with a caliper of 0.05. RESULTS: After exclusion and matching, 3857 patients had preoperative CEA levels ≤ 5 ng/ml, 1121 patients had CEA levels between 5 and 10 ng/ml, and 1121 patients had CEA levels > 10 ng/ml. Elevated preoperative CEA showed an increased risk of overall survival (5-10 ng/ml: hazard ratio [HR] 1.376; > 10 ng/ml: HR 1.523; both p < 0.001), cancer-specific survival (5-10 ng/ml: HR 1.404; > 10 ng/ml: HR 1.712; both p < 0.001), and recurrence free interval (5-10 ng/ml: HR 1.190; > 10 ng/ml: HR 1.468; both p < 0.05). Patients with negative lymph node staging (LNs) and CEA > 10 ng/ml, as well as those with positive LNs and CEA ≤ 5 ng/ml, showed similar overall survival (5-year survival: 72% vs. 69%; p = 0.542) and recurrence free intervals (19.9 vs. 21.72 months; p = 0.662). CONCLUSIONS: A preoperative CEA level can be an independent prognostic factor for stage I-III CRC after curative resection. Patients with negative LNs and preoperative CEA level > 10 ng/ml should be considered for intensive follow-up or adjuvant chemotherapy.

Fabrication of silver nanoclusters with enhanced fluorescence triggered by ethanol solvent: a selective fluorescent probe for Cr3+ detection.

We present a facile method for the preparation of red-emitting and water-soluble silver nanoclusters (Ag NCs) using dihydrolipoic acid and sodium borohydride as the template and reducing agent. Ethanol solvent is demonstrated to endow Ag NCs with dramatically enhanced fluorescence; therefore, the Ag NCs are synthesized in ethanol/water solution (e/w-Ag NCs) instead of aqueous solution. Specific trivalent chromium (Cr3+) recognition capability of the e/w-Ag NCs can thus be obtained on the basis of its fluorescence quenching. The mechanisms for fluorescence enhancement and quenching of the e/w-Ag NCs triggered by ethanol and Cr3+, respectively, are investigated in detail. Next, a fluorescence method for detection of Cr3+ is established and its analytical performance is evaluated: the detection limit for Cr3+ is 0.71 µM and the linear range is from 2 to 40 µM. The fluorescent probe exhibits sufficient sensitivity and good selectivity toward Cr3+, illustrating that it has great promise for practical application in Cr3+ detection.

PVC flooring at home and uptake of phthalates in pregnant women.

Phthalates are used as plasticizers in polyvinyl chloride (PVC) materials and it is known that phthalates may migrate into the surrounding environment and then become a source for human uptake. The aim of the study was to investigate whether residential PVC flooring was related to the urinary levels of phthalate metabolites determined in pregnant women. The data were from the Swedish SELMA study where sampling was conducted during the time period 2007-2010. Spot urine samples from 1674 women at the end of the first trimester were analyzed for 14 metabolites from seven phthalates and one phthalate alternative. Data on flooring material in the kitchen and the parents' bedrooms as well as potential confounders were collected by postal questionnaires at the same time as the urine samples were taken. Multiple regression modeling by least square geometric mean and weighted quantile sum regression was applied to log-transformed and creatinine-adjusted phthalate metabolite concentrations adjusted for potential confounders from questionnaire data. This study has found significantly higher urinary levels of the BBzP metabolite (MBzP) in pregnant women living in homes with PVC flooring as compared to homes with other flooring materials.

A Novel Approach to Chemical Mixture Risk Assessment-Linking Data from Population-Based Epidemiology and Experimental Animal Tests.

Humans are continuously exposed to chemicals with suspected or proven endocrine disrupting chemicals (EDCs). Risk management of EDCs presents a major unmet challenge because the available data for adverse health effects are generated by examining one compound at a time, whereas real-life exposures are to mixtures of chemicals. In this work, we integrate epidemiological and experimental evidence toward a whole mixture strategy for risk assessment. To illustrate, we conduct the following four steps in a case study: (1) identification of single EDCs ("bad actors")-measured in prenatal blood/urine in the SELMA study-that are associated with a shorter anogenital distance (AGD) in baby boys; (2) definition and construction of a "typical" mixture consisting of the "bad actors" identified in Step 1; (3) experimentally testing this mixture in an in vivo animal model to estimate a dose-response relationship and determine a point of departure (i.e., reference dose [RfD]) associated with an adverse health outcome; and (4) use a statistical measure of "sufficient similarity" to compare the experimental RfD (from Step 3) to the exposure measured in the human population and generate a "similar mixture risk indicator" (SMRI). The objective of this exercise is to generate a proof of concept for the systematic integration of epidemiological and experimental evidence with mixture risk assessment strategies. Using a whole mixture approach, we could find a higher rate of pregnant women under risk (13%) when comparing with the data from more traditional models of additivity (3%), or a compound-by-compound strategy (1.6%).

Prenatal phthalate exposure was associated with croup in Swedish infants.

AIM: This study examined whether prenatal phthalate exposure was associated with lower or upper airway inflammation in infants. METHODS: From 2007 to 2010, we used liquid chromatography-tandem mass spectrometry, adjusted for creatinine, to analyse 14 phthalate metabolites and one phthalate replacement in the urine of 1062 Swedish mothers at a median of 10 weeks of pregnancy. This was used to determine any associations between prenatal phthalate exposure and croup, wheezing or otitis in their offspring until 12 months of age, using logistic regression, adjusted for potential confounders. RESULTS: There were significant associations between phthalate metabolites of butyl-benzyl phthalate (BBzP) and di-ethyl-hexyl phthalate (DEHP) concentrations in maternal prenatal urine and croup in 1062 infants during the first year of life, when adjusted for potential confounders. A dose-response relationship was found between prenatal phthalates exposure and maternal reported croup in the children, with a significant association in boys. There was no clear indication with regard to associations between prenatal phthalate exposure and wheezing or otitis media in the children during the first year of life. CONCLUSION: Our analysis suggests that exposure to BBzP and DEHP phthalates was associated with maternal reports of croup in infants up to 12 months of age.

H3K36ac Is an Evolutionary Conserved Plant Histone Modification That Marks Active Genes.

In eukaryotic cells, histones are subject to a large number of posttranslational modifications whose sequential or combinatorial action affects chromatin structure and genome function. We identified acetylation at Lys-36 in histone H3 (H3K36ac) as a new chromatin modification in plants. The H3K36ac modification is evolutionary conserved in seed plants, including the gymnosperm Norway spruce (Picea abies) and the angiosperms rice (Oryza sativa), tobacco (Nicotiana tabacum), and Arabidopsis (Arabidopsis thaliana). In Arabidopsis, H3K36ac is highly enriched in euchromatin but not in heterochromatin. Genome-wide chromatin immunoprecipitation sequencing experiments revealed that H3K36ac peaks at the 5' end of genes, mainly on the two nucleosomes immediately distal to the transcription start site, independently of gene length. H3K36ac overlaps with H3K4me3 and the H2A.Z histone variant. The histone acetyl transferase GCN5 and the histone deacetylase HDA19 are required for H3K36ac homeostasis. H3K36ac and H3K36me3 show negative crosstalk, which is mediated by GCN5 and the histone methyl transferase SDG8. Although H3K36ac is associated with gene activity, we did not find a linear relationship between H3K36ac and transcript levels, suggesting that H3K36ac is a binary indicator of transcription.