The neuropeptide oxytocin (OXT) exerts anxiolytic and prosocial effects in the central nervous system of rodents. A number of recent studies have attempted to translate these findings by ...investigating the relationships between peripheral (e.g., blood, urinary and salivary) OXT concentrations and behavioral functioning in humans. Although peripheral samples are easy to obtain in humans, whether peripheral OXT measures are functionally related to central OXT activity remains unclear. To investigate a possible relationship, we quantified OXT concentrations in concomitantly collected cerebrospinal fluid (CSF) and blood samples from child and adult patients undergoing clinically indicated lumbar punctures or other CSF-related procedures. Anxiety scores were obtained in a subset of child participants whose parents completed psychometric assessments. Findings from this study indicate that plasma OXT concentrations significantly and positively predict CSF OXT concentrations (r=0.56, P=0.0064, N=27). Moreover, both plasma (r=-0.92, P=0.0262, N=10) and CSF (r=-0.91, P=0.0335, N=10) OXT concentrations significantly and negatively predicted trait anxiety scores, consistent with the preclinical literature. Importantly, plasma OXT concentrations significantly and positively (r=0.96, P=0.0115, N=10) predicted CSF OXT concentrations in the subset of child participants who provided behavioral data. This study provides the first empirical support for the use of blood measures of OXT as a surrogate for central OXT activity, validated in the context of behavioral functioning. These preliminary findings also suggest that impaired OXT signaling may be a biomarker of anxiety in humans, and a potential target for therapeutic development in individuals with anxiety disorders.
Pathological shifts of the human microbiome are characteristic of many diseases, including chronic periodontitis. To date, there is limited evidence on host genetic risk loci associated with ...periodontal pathogen colonization. We conducted a genome-wide association (GWA) study among 1,020 white participants of the Atherosclerosis Risk in Communities Study, whose periodontal diagnosis ranged from healthy to severe chronic periodontitis, and for whom “checkerboard” DNA-DNA hybridization quantification of 8 periodontal pathogens was performed. We examined 3 traits: “high red” and “high orange” bacterial complexes, and “high” Aggregatibacter actinomycetemcomitans (Aa) colonization. Genotyping was performed on the Affymetrix 6.0 platform. Imputation to 2.5 million markers was based on HapMap II-CEU, and a multiple-test correction was applied (genome-wide threshold of p < 5 × 10−8). We detected no genome-wide significant signals. However, 13 loci, including KCNK1, FBXO38, UHRF2, IL33, RUNX2, TRPS1, CAMTA1, and VAMP3, provided suggestive evidence (p < 5 × 10−6) of association. All associations reported for “red” and “orange” complex microbiota, but not for Aa, had the same effect direction in a second sample of 123 African-American participants. None of these polymorphisms was associated with periodontitis diagnosis. Investigations replicating these findings may lead to an improved understanding of the complex nature of host-microbiome interactions that characterizes states of health and disease.
Metabolic syndrome comprises a cluster of related disorders that includes obesity, glucose intolerance, insulin resistance, dyslipidemia, and fatty liver. Recently, gut-derived chronic endotoxemia ...has been identified as a primary mediator for triggering the low-grade inflammation responsible for the development of metabolic syndrome. In the present study we examined the role of the small intestinal brush-border enzyme, intestinal alkaline phosphatase (IAP), in preventing a high-fat-diet–induced metabolic syndrome in mice. We found that both endogenous and orally supplemented IAP inhibits absorption of endotoxin (lipopolysaccharides) that occurs with dietary fat, and oral IAP supplementation prevents as well as reverses metabolic syndrome. Furthermore, IAP supplementation improves the lipid profile in mice fed a standard, low-fat chow diet. These results point to a potentially unique therapy against metabolic syndrome in at-risk humans.
Chronic periodontitis (CP) is a common oral disease that confers substantial systemic inflammatory and microbial burden and is a major cause of tooth loss. Here, we present the results of a ...genome-wide association study of CP that was carried out in a cohort of 4504 European Americans (EA) participating in the Atherosclerosis Risk in Communities (ARIC) Study (mean age-62 years, moderate CP-43% and severe CP-17%). We detected no genome-wide significant association signals for CP; however, we found suggestive evidence of association (P < 5 × 10(-6)) for six loci, including NIN, NPY, WNT5A for severe CP and NCR2, EMR1, 10p15 for moderate CP. Three of these loci had concordant effect size and direction in an independent sample of 656 adult EA participants of the Health, Aging, and Body Composition (Health ABC) Study. Meta-analysis pooled estimates were severe CP (n = 958 versus health: n = 1909)-NPY, rs2521634 G: odds ratio OR = 1.49 (95% confidence interval (CI = 1.28-1.73, P = 3.5 × 10(-7))); moderate CP (n = 2293)-NCR2, rs7762544 G: OR = 1.40 (95% CI = 1.24-1.59, P = 7.5 × 10(-8)), EMR1, rs3826782 A: OR = 2.01 (95% CI = 1.52-2.65, P = 8.2 × 10(-7)). Canonical pathway analysis indicated significant enrichment of nervous system signaling, cellular immune response and cytokine signaling pathways. A significant interaction of NUAK1 (rs11112872, interaction P = 2.9 × 10(-9)) with smoking in ARIC was not replicated in Health ABC, although estimates of heritable variance in severe CP explained by all single nucleotide polymorphisms increased from 18 to 52% with the inclusion of a genome-wide interaction term with smoking. These genome-wide association results provide information on multiple candidate regions and pathways for interrogation in future genetic studies of CP.
The intestinal microbiota plays a critical role in maintaining human health; however, the mechanisms governing the normal homeostatic number and composition of these microbes are largely unknown. ...Previously it was shown that intestinal alkaline phosphatase (IAP), a small intestinal brush border enzyme, functions as a gut mucosal defence factor limiting the translocation of gut bacteria to mesenteric lymph nodes. In this study the role of IAP in the preservation of the normal homeostasis of the gut microbiota was investigated.
Bacterial culture was performed in aerobic and anaerobic conditions to quantify the number of bacteria in the stools of wild-type (WT) and IAP knockout (IAP-KO) C57BL/6 mice. Terminal restriction fragment length polymorphism, phylogenetic analyses and quantitative real-time PCR of subphylum-specific bacterial 16S rRNA genes were used to determine the compositional profiles of microbiotas. Oral supplementation of calf IAP (cIAP) was used to determine its effects on the recovery of commensal gut microbiota after antibiotic treatment and also on the colonisation of pathogenic bacteria.
IAP-KO mice had dramatically fewer and also different types of aerobic and anaerobic microbes in their stools compared with WT mice. Oral supplementation of IAP favoured the growth of commensal bacteria, enhanced restoration of gut microbiota lost due to antibiotic treatment and inhibited the growth of a pathogenic bacterium (Salmonella typhimurium).
IAP is involved in the maintenance of normal gut microbial homeostasis and may have therapeutic potential against dysbiosis and pathogenic infections.
Malaria is an infectious disease caused by parasites of the genus Plasmodium, which leads to approximately one million deaths per annum worldwide. Chemical validation of new antimalarial targets is ...urgently required in view of rising resistance to current drugs. One such putative target is the enzyme N-myristoyltransferase, which catalyses the attachment of the fatty acid myristate to protein substrates (N-myristoylation). Here, we report an integrated chemical biology approach to explore protein myristoylation in the major human parasite P. falciparum, combining chemical proteomic tools for identification of the myristoylated and glycosylphosphatidylinositol-anchored proteome with selective small-molecule N-myristoyltransferase inhibitors. We demonstrate that N-myristoyltransferase is an essential and chemically tractable target in malaria parasites both in vitro and in vivo, and show that selective inhibition of N-myristoylation leads to catastrophic and irreversible failure to assemble the inner membrane complex, a critical subcellular organelle in the parasite life cycle. Our studies provide the basis for the development of new antimalarials targeting N-myristoyltransferase.
Abstract
STUDY QUESTION
Do the outcomes and use of ART differ between women with and without endometriosis?
SUMMARY ANSWER
ART use and outcome do not appear to differ for women with and without ...endometriosis, as long as endometriosis is diagnosed prior to commencing ART.
WHAT IS KNOWN ALREADY
Approximately 40% of women with endometriosis have infertility and ART is the recommended treatment option for these women. However, diagnosis of endometriosis can be complex and lengthy, and a delay in diagnosis can reduce the likelihood of achieving a live birth.
STUDY DESIGN, SIZE, DURATION
This retrospective national cohort study used longitudinal self-report data (collected 1996–2018) from women born in 1973–1978 who are participants in the Australian Longitudinal Study on Women’s Health (ALSWH). The study also used linked administrative data on Endometriosis (1970–2018), ART (1996–2020) and births (1996–2018).
PARTICIPANTS/MATERIALS, SETTING, METHODS
The outcome measures were: age at first ART cycle; use of ART treatments (IVF only; IUI only/and IVF); number of ART cycles (1–3; 4–10; 11–36); and births after first ART (no; yes) (note that births could not be tied to ART).
MAIN RESULTS AND THE ROLE OF CHANCE
One in three (34.7%, n = 459/1322) women using ART had endometriosis, with 65.6% of these diagnosed before first ART and 34.4% after. Adjusted regression analyses showed women with endometriosis diagnosed before first ART were not significantly different to women without endometriosis on any outcome. However, women with endometriosis diagnosed after first ART were more likely to use IUI (adjusted odds ratio (aOR) 2.14, 95% CI 1.48, 3.09) and do more cycles (11–36 cycles: aOR 4.09, 95% CI 2.41, 6.95), and less likely to report a birth (aOR 0.67, 95% CI 0.45, 0.99), compared to women without endometriosis, despite no significant difference in starting age (coefficient = −0.62, 95% CI −1.36, 0.13).
LIMITATIONS, REASONS FOR CAUTION
We did not have information on the severity of endometriosis, or the reasons for using ART, which can influence treatment and outcomes. We were not able to reliably link births with ART treatment. Finally, it is possible that some of the women in our ‘no endometriosis’ group did have endometriosis and were unaware of it, although prevalence rates match population estimates.
WIDER IMPLICATIONS OF THE FINDINGS
These findings support previous studies that have found no difference in outcome of ART for women with endometriosis, but add the new insight that this is only true if endometriosis is diagnosed prior to commencing ART. A delayed diagnosis can create disadvantage during ART treatment. Early recourse to IVF may be advantageous for pregnancy prospects for women with endometriosis.
STUDY FUNDING/COMPETING INTEREST(S)
The ALSWH is funded by the Australian Government Department of Health. G.D.M. is supported by an NHMRC Principal Research Fellowship (APP11218449). The authors have no conflicts of interest to declare.
TRIAL REGISTRATION NUMBER
N/A.
Recent genome-wide association studies (GWAS) of chronic periodontitis (CP) offer rich data sources for the investigation of candidate genes, functional elements, and pathways. We used GWAS data of ...CP (n = 4,504) and periodontal pathogen colonization (n = 1,020) from a cohort of adult Americans of European descent participating in the Atherosclerosis Risk in Communities study and employed a MAGENTA approach (i.e., meta-analysis gene set enrichment of variant associations) to obtain gene-centric and gene set association results corrected for gene size, number of single-nucleotide polymorphisms, and local linkage disequilibrium characteristics based on the human genome build 18 (National Center for Biotechnology Information build 36). We used the Gene Ontology, Ingenuity, KEGG, Panther, Reactome, and Biocarta databases for gene set enrichment analyses. Six genes showed evidence of statistically significant association: 4 with severe CP (NIN, p = 1.6 × 10−7; ABHD12B, p = 3.6 × 10−7; WHAMM, p = 1.7 × 10−6; AP3B2, p = 2.2 × 10−6) and 2 with high periodontal pathogen colonization (red complex–KCNK1, p = 3.4 × 10−7; Porphyromonas gingivalis–DAB2IP, p = 1.0 × 10−6). Top-ranked genes for moderate CP were HGD (p = 1.4 × 10−5), ZNF675 (p = 1.5 × 10−5), TNFRSF10C (p = 2.0 × 10−5), and EMR1 (p = 2.0 × 10−5). Loci containing NIN, EMR1, KCNK1, and DAB2IP had showed suggestive evidence of association in the earlier single-nucleotide polymorphism–based analyses, whereas WHAMM and AP2B2 emerged as novel candidates. The top gene sets included severe CP (“endoplasmic reticulum membrane,” “cytochrome P450,” “microsome,” and “oxidation reduction”) and moderate CP (“regulation of gene expression,” “zinc ion binding,” “BMP signaling pathway,” and “ruffle”). Gene-centric analyses offer a promising avenue for efficient interrogation of large-scale GWAS data. These results highlight genes in previously identified loci and new candidate genes and pathways possibly associated with CP, which will need to be validated via replication and mechanistic studies.
Polyethylene is a widely used plastic exhibiting a large range of properties that depend on molecular weight, crystallinity, chain branching, and cross-linking. In this study, the sound speeds and ...elastic properties of a variety of commercially available polyethylene materials were experimentally determined using the pulse-echo ultrasound technique. In situ pressure dependent measurements, including ultrasound time of flight, x-ray diffraction, and x-ray radiography, were performed using a Paris-Edinburgh large volume press at the High Pressure Collaborative Access Team (HPCAT), beamline 16-BM-B at the Advanced Photon Source. Polyethylene sound speed and elastic moduli were found to increase with increasing pressure. The zero pressure orthorhombic phase was found to transform to monoclinic at low pressures of ~0.1 GPa.
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•Sound speed and elastic constants in polyethylene increase with increasing density.•Sound speed sharply increases at low pressure due to compression of free volume.•Stress-induced martensitic phase transformation observed at very low pressure.
The purpose of this study was to evaluate the associations between interdental cleaning behavior and the prevalence of caries and periodontal disease and numbers of missing teeth, with data from the ...National Health and Nutrition Examination Survey (2011 to 2012 and 2013 to 2014). Analysis included the following parameters: interproximal clinical attachment level (iCAL) ≥3 mm, interproximal probing depth (iPD) ≥4 mm, number of coronal and interproximal caries, number of missing teeth, ≥1 surfaces with coronal caries, and periodontal profile classes (PPCs). Chi-square was used for bivariate associations. Associations of interdental cleaning with outcomes were assessed with multiple linear regression and generalized logit regression, adjusting for age, race, sex, diabetes, smoking, education, dental visits, and sugar consumption. Nonusers had a significantly higher percentage of sites with iCAL ≥3 mm and iPD ≥4 mm as compared with individuals who used interdental cleaning devices (P < 0.0001). Individuals with a higher frequency of cleaning (4 to 7×/wk) had a significantly lower extent of sites with iCAL ≥3 mm as compared with lower-frequency cleaning (1 to 3×/wk; P ≤ 0.05). Interdental cleaning users showed lower numbers of coronal caries, interproximal coronal caries, and missing teeth as compared with nonusers (P < 0.0001). Nonusers had 1.73-times (95% confidence interval, 1.53 to 1.94) higher odds for having ≥1 surfaces of coronal caries as compared with interdental cleaning users, regardless of the weekly frequency. Individuals were less likely to be in diseased PPCs if they were interdental cleaning users. Low-frequency cleaners (1 to 3×/wk) had significantly greater odds (1.43; 95% confidence interval, 1.08 to 1.88) to have severe disease (PPC-G) versus health (PPC-A) than were high-frequency cleaners (4 to 7×/wk). Interdental cleaning users showed lower levels of periodontal disease and caries and lower numbers of missing teeth. Higher frequency of interdental cleaning was correlated with increased periodontal health. Individuals with severe periodontal disease could show additional oral health benefits by increasing cleaning frequency. The data support the use of interdental cleaning devices as an oral hygiene behavior for promoting health.