Multivariate Association Analysis Research Articles

Total Laparoscopic Hysterectomy – Analysis of Learning Points & Complications over a Span of Two Decades.

Study Objective 1. Analysis of learning curve for Total laparoscopic hysterectomy (TLH); 2. Comparison of complication rates of 773 TLH between 1st & 2nd decade. Design Retrospective comparative analysis of prospectively collected data (Canadian Task force II – 2). Setting Centre for Endoscopic Surgery. Patients or Participants Total 773 patients posted for TLH over 20-years (2000-2019) for benign pathology excluding malignancy, anesthetic unfit and pelvic organ prolapse cases. Interventions Total Laparoscopic Hysterectomy with or without Bilateral Salpingo-oophorectomy. Measurements and Main Results All cases were divided into initial 10-years (group-I) of 386 cases and later 10-years (group-II) of 387 cases. No difference found in patient's demographic characteristic between first and second group. Analysis was done from prospectively collected data from outpatient and inpatient records elucidated in a structure pre-set protocol. Intra-operative variants were reviewed from real time video graphic records. Statistical method used, mean and standard deviation for operating time. P value for statistical significance. Chi-square test & Student t-test for continuous and categorical variables. Odd Ratio, univariate & multivariate logistic regression analysis for association. Significant reduction in mean operative-time was observed in first 125 to 250th case of TLH (p=0.001) which reflects the impact of learning. Comparison between group-I and group-II revealed significant reduction in major and minor complication rate from 3.35% to 1.03% (p=0.0277) and 1.81% to 0.25% (p = 0.033) respectively. The bladder complication in group-I and II were 8 & 2 respectively and only group-I had 4 ureteric and 1 bowel injury. Conversion rate was 7.3% throughout where endometriosis, 2 previous LSCS & bowel adhesions emerged as the strongest predictors of conversion with OR=6.72, 4.71 & 2.57 respectively. Conclusion Appropriate supervised training and increased experience after learning curve leads to marked reduction in operative time and complication rates of TLH. Conversion rate is independent of experience. 1. Analysis of learning curve for Total laparoscopic hysterectomy (TLH); 2. Comparison of complication rates of 773 TLH between 1st & 2nd decade. Retrospective comparative analysis of prospectively collected data (Canadian Task force II – 2). Centre for Endoscopic Surgery. Total 773 patients posted for TLH over 20-years (2000-2019) for benign pathology excluding malignancy, anesthetic unfit and pelvic organ prolapse cases. Total Laparoscopic Hysterectomy with or without Bilateral Salpingo-oophorectomy. All cases were divided into initial 10-years (group-I) of 386 cases and later 10-years (group-II) of 387 cases. No difference found in patient's demographic characteristic between first and second group. Analysis was done from prospectively collected data from outpatient and inpatient records elucidated in a structure pre-set protocol. Intra-operative variants were reviewed from real time video graphic records. Statistical method used, mean and standard deviation for operating time. P value for statistical significance. Chi-square test & Student t-test for continuous and categorical variables. Odd Ratio, univariate & multivariate logistic regression analysis for association. Significant reduction in mean operative-time was observed in first 125 to 250th case of TLH (p=0.001) which reflects the impact of learning. Comparison between group-I and group-II revealed significant reduction in major and minor complication rate from 3.35% to 1.03% (p=0.0277) and 1.81% to 0.25% (p = 0.033) respectively. The bladder complication in group-I and II were 8 & 2 respectively and only group-I had 4 ureteric and 1 bowel injury. Conversion rate was 7.3% throughout where endometriosis, 2 previous LSCS & bowel adhesions emerged as the strongest predictors of conversion with OR=6.72, 4.71 & 2.57 respectively. Appropriate supervised training and increased experience after learning curve leads to marked reduction in operative time and complication rates of TLH. Conversion rate is independent of experience.

A Multivariate Analysis of Genome-Wide Association (GWAS) Data to Identify Genes Associated with CKD

A Multivariate Analysis of Genome-Wide Association (GWAS) Data to Identify Genes Associated with CKD

Sleep as a Priority: 24-Hour Movement Guidelines and Mental Health of Chinese College Students during the COVID-19 Pandemic.

Research on the combined role of 24-hour movement behaviors (sleep, sedentary behavior [SB], and physical activity) in adult mental health, though important, is in its infancy. In the context of Canadian 24-hour movement guidelines integrating quantitative recommendations for sleep, SB, and moderate-to-vigorous physical activity (MVPA), this study aimed to examine the associations between meeting guidelines and mental health among college students. The study used a cross-sectional sample of 1846 Chinese college students surveyed online in August 2020. Through network analysis and multivariate analysis of covariance, the individual and combined associations between meeting 24-hour movement guidelines and the levels of depression and anxiety after adjusting sociodemographic factors were analyzed. Results indicated that meeting the sleep guideline had stronger associations with depression and anxiety than meeting the SB or MVPA guideline. Specifically, compared to meeting no guidelines, meeting the sleep guideline (alone or in combination with other guidelines) was associated with significantly lower levels of depression and anxiety; meeting both SB and MVPA guidelines was also associated with a significantly lower level of depression. Hence, meeting more guidelines, especially adhering to a healthy sleep routine, may play an important role in promoting the mental health of young adults.

Genetic analysis of dietary intake identifies new loci and functional links with metabolic traits.

Dietary intake is a major contributor to the global obesity epidemic and represents a complex behavioural phenotype that is partially affected by innate biological differences. Here, we present a multivariate genome-wide association analysis of overall variation in dietary intake to account for the correlation between dietary carbohydrate, fat and protein in 282,271 participants of European ancestry from the UK Biobank (n = 191,157) and Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium (n = 91,114), and identify 26 distinct genome-wide significant loci. Dietary intake signals map exclusively to specific brain regions and are enriched for genes expressed in specialized subtypes of GABAergic, dopaminergic and glutamatergic neurons. We identified two main clusters of genetic variants for overall variation in dietary intake that were differently associated with obesity and coronary artery disease. These results enhance the biological understanding of interindividual differences in dietary intake by highlighting neural mechanisms, supporting functional follow-up experiments and possibly providing new avenues for the prevention and treatment of prevalent complex metabolic diseases.

Clinical Significance of Raynaud Phenomenon in Systemic Lupus Erythematosus.

There are limited reports of the clinical significance of Raynaud phenomenon (RP) in systemic lupus erythematosus (SLE), with some suggesting RP is associated with less severe lupus. Since most prior studies were small and/or focused on a specific race/ethnic demographic, it is unclear if those results are generalizable. We evaluated whether RP was associated with demographic and clinical factors in a large multiethnic SLE cohort. We studied Montreal General Hospital SLE cohort patients who are followed with standardized annual assessments. We included patients with at least 1 visit across 2011-2018 and assessed demographic and clinical variables (using the 1997 American College of Rheumatology criteria and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index) at their first visit. We present multivariate logistics regression analyses of cross-sectional associations between these variables and RP in SLE. Of 489 SLE patients, most were female (n = 445, 91%). Mean age at SLE diagnosis was 31.5 (standard deviation, 13.5) years, and 169 (34.6%) had RP. In our fully adjusted model, female sex (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.07-6.03), White race/ethnicity (OR, 1.85; 95% CI, 1.10-3.17), neurological/neuropsychiatric manifestations (OR, 1.98; 95% CI, 1.10-3.56), and anti-RNP antibodies (OR, 3.03; 95% CI, 1.73-5.38) were positively associated with RP, whereas hemolytic anemia and cellular casts were negatively associated. Over one third of our large multiethnic North American SLE cohort had RP. This study confirmed associations between RP and a specific SLE phenotype.

Sex-Specific Relationship between the Cardiorespiratory Fitness and Plasma Metabolite Patterns in Healthy Humans-Results of the KarMeN Study.

Cardiorespiratory fitness (CRF) represents a strong predictor of all-cause mortality and is strongly influenced by regular physical activity (PA). However, the biological mechanisms involved in the body’s adaptation to PA remain to be fully elucidated. The aim of this study was to systematically examine the relationship between CRF and plasma metabolite patterns in 252 healthy adults from the cross-sectional Karlsruhe Metabolomics and Nutrition (KarMeN) study. CRF was determined by measuring the peak oxygen uptake during incremental exercise. Fasting plasma samples were analyzed by nuclear magnetic resonance spectroscopy and mass spectrometry coupled to one- or two-dimensional gas chromatography or liquid chromatography. Based on this multi-platform metabolomics approach, 427 plasma analytes were detected. Bi- and multivariate association analyses, adjusted for age and menopausal status, showed that CRF was linked to specific sets of metabolites primarily indicative of lipid metabolism. However, CRF-related metabolite patterns largely differed between sexes. While several phosphatidylcholines were linked to CRF in females, single lyso-phosphatidylcholines and sphingomyelins were associated with CRF in males. When controlling for further assessed clinical and phenotypical parameters, sex-specific CRF tended to be correlated with a smaller number of metabolites linked to lipid, amino acid, or xenobiotics-related metabolism. Interestingly, sex-specific CRF explanation models could be improved when including selected plasma analytes in addition to clinical and phenotypical variables. In summary, this study revealed sex-related differences in CRF-associated plasma metabolite patterns and proved known associations between CRF and risk factors for cardiometabolic diseases such as fat mass, visceral adipose tissue mass, or blood triglycerides in metabolically healthy individuals. Our findings indicate that covariates like sex and, especially, body composition have to be considered when studying blood metabolic markers related to CRF.

Microbial-induced concrete corrosion under high-salt conditions: Microbial community composition and environmental multivariate association analysis

The corrosion of concrete materials in urban sewage pipes by microorganisms is a serious issue in wastewater networks around the world. There has been no systematic study conducted on material corrosion by microorganisms, particularly for high-salt environments in coastal cities. This study compared and analysed reactors under different salinities, and the 16S ribosomal ribonucleic acid gene sequence method was used to analyze the bacterial communities associated with concrete corrosion. Redundancy analysis demonstrated that chemical oxygen demand, volatile fatty acids, and sulphate altered the structure and distribution of the microbial community. The predominant bacteria, Proteobacteria, accounted for 41.85% of the seawater group. Among them, the sulphur functional microorganism, Desulfomicrobium, accounted for 4.14%. These bacteria can decompose macromolecular organic matter to provide energy for reproduction. Furthermore, they continue to provide sulphur for the eosinophilic sulphur-oxidising bacteria attached to the surface of the high alkaline concrete sample. The aggregated sulphur-oxidising bacteria produce biological sulphuric acid, leading to corrosion and damage to the concrete structure. Salinity promoted the aggregation of corrosion-inducing bacteria, accelerating the growth of corroding microorganisms on the concrete material of coastal urban sewage pipes.

Prolonged Lenalidomide Therapy Does Not Impact Autologous Peripheral Blood Stem Cell Mobilization and Collection in Multiple Myeloma Patients: A Single-Center Retrospective Analysis

Since the introduction of lenalidomide into induction therapy for multiple myeloma (MM), there have been conflicting reports about its impact on autologous peripheral blood stem cell (PBSC) mobilization. We evaluated the impact of previous lenalidomide exposure in a large cohort of patients with MM undergoing mobilization and collection at a tertiary stem cell transplantation center. We hypothesized that collection of PBSCs is feasible even with a prolonged duration of previous lenalidomide therapy. We examined patients with MM who attempted stem cell mobilization and collection, seen at our center between January 2012 and July 2015. The patients were categorized into 3 groups for analysis: (1) patients with previous receipt of >6 cycles lenalidomide, (2) patients with previous receipt of ≤6 cycles of lenalidomide, and (3) patients without previous lenalidomide exposure. We compared collection yields and days of apheresis among the 3 groups using linear regression analysis. We identified 297 patients with MM who underwent mobilization of PBSCs. Of these, 35 had received >6 cycles of lenalidomide (median, 8 cycles; range, 7 to 25 cycles), 156 had received ≤6 cycles of lenalidomide (median, 4 cycles; range, 1 to 6 cycles), and 106 had received no lenalidomide. Prior lenalidomide exposure did not have a statistically significant impact on the absolute number of CD34+ cells collected or on the duration of collection based on a multivariate linear regression analysis for association between receipt of >6 cycles of lenalidomide. In this retrospective analysis of MM patients undergoing autologous PBSC transplantation, we show that the duration of previous lenalidomide exposure does not impact the total number of PBSCs collected or the number of days of apheresis. These data suggest that longer courses of induction therapy with lenalidomide-containing regimens to achieve a maximum response can be safe without impairing the ability to collect PBSCs, and that limiting lenalidomide use before mobilization does not appear warranted in all cases.

Sarcopenia and modified Glasgow Prognostic Score predict postsurgical outcomes in localized renal cell carcinoma.

Body composition and inflammation are gaining importance for prognostication in cancer. This study investigated the individual and combined utility of the preoperative skeletal muscle index (SMI) and the modified Glasgow Prognostic Score (mGPS) for estimating postoperative outcomes in patients with localized renal cell carcinoma (RCC) undergoing nephrectomy. The authors performed a retrospective review of 352 patients with localized RCC. SMI was measured via computed tomography or magnetic resonance imaging. Patients met the criteria for sarcopenia by body mass index- and sex-stratified thresholds. Multivariable and Kaplan-Meier analyses of associations of sarcopenia and mGPS with overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) were performed. Variables were analyzed independently and combined into risk groups: low risk (nonsarcopenic, low mGPS), medium risk (sarcopenia only), medium risk (inflammation only), and high risk (sarcopenic, high mGPS). Receiver operating characteristic (ROC) curves were used to analyze risk groups in comparison with the Stage, Size, Grade, and Necrosis (SSIGN) score and the modified International Metastatic RCC Database Consortium (IMDC) score. The majority of the patients were at stage pT3 (63%), 39.5% of the patients were sarcopenic, and 19.3% had an elevated mGPS at the baseline. The median follow-up time was 30.4 months. Sarcopenia and mGPS were independently associated with worse OS (hazard ratio for sarcopenia, 1.64; P = .006; hazard ratio for mGPS, 1.72; P = .012), CSS, and RFS. Risk groups had an increasing association with worse RFS (P = .015) and CSS (P = .004) but not OS (P = .087). ROC analyses demonstrated a higher area under the curve for risk groups in comparison with the SSIGN and IMDC scores at 5 years. Sarcopenia and an elevated mGPS were associated with worse clinical outcomes in this study of patients with localized RCC. This has implications for preoperative prognostication and treatment decision-making. Kidney cancer is a disease with a wide variety of outcomes. Among patients undergoing surgical removal of the kidney for cancer that has not spread beyond the kidney, many are cured, but some experience recurrence. Physicians are seeking ways to better predict who is at risk for recurrence or death from kidney cancer. This study has evaluated body composition and markers of inflammation before surgery to predict the risk of recurrence or death after surgery. Specifically, low muscle mass and an elevated inflammation score (the modified Glasgow Prognostic Score) have been associated with an increased likelihood of recurrence of kidney cancer and death.

Multivariate genome-wide analysis of immunoglobulin G N-glycosylation identifies new loci pleiotropic with immune function.

The N-glycosylation of immunoglobulin G (IgG) affects its structure and function. It has been demonstrated that IgG N-glycosylation patterns are inherited as complex quantitative traits. Genome-wide association studies identified loci harboring genes encoding enzymes directly involved in protein glycosylation as well as loci likely to be involved in regulation of glycosylation biochemical pathways. Many of these loci could be linked to immune functions and risk of inflammatory and autoimmune diseases. The aim of the present study was to discover and replicate new loci associated with IgG N-glycosylation and to investigate possible pleiotropic effects of these loci onto immune function and the risk of inflammatory and autoimmune diseases. We conducted a multivariate genome-wide association analysis of 23 IgG N-glycosylation traits measured in 8090 individuals of European ancestry. The discovery stage was followed up by replication in 3147 people and in silico functional analysis. Our study increased the total number of replicated loci from 22 to 29. For the discovered loci, we suggest a number of genes potentially involved in the control of IgG N-glycosylation. Among the new loci, two (near RNF168 and TNFRSF13B) were previously implicated in rare immune deficiencies and were associated with levels of circulating immunoglobulins. For one new locus (near AP5B1/OVOL1), we demonstrated a potential pleiotropic effect on the risk of asthma. Our findings underline an important link between IgG N-glycosylation and immune function and provide new clues to understanding their interplay.

Associations of circulating cell-free DNA (cfDNA) and clinical outcomes in metastatic castrate-resistant prostate cancer (mCRPC).

137 Background: Genomic profiling of patients (pts) with mCRPC is becoming more widely utilized to assist in prognosis and treatment. Liquid biopsies offer a non-invasive method of assessing gene alterations but questions remain regarding their validity, as well as the association of these alterations with relevant clinical outcomes. Methods: We present a retrospective analysis of 82 pts who underwent genomic profiling at the onset of mCRPC using the Guardant360 cfDNA assay. Clinical outcomes data was recorded in a structured note in the electronic medical record that allowed discrete data elements to be stored and analyzed. Patients received standard treatment with Abiraterone (Abi) and Enzalutamide (Enza) as well as chemotherapy. Relevant clinical outcome endpoints included overall survival (OS) and time on treatment with Abi and Enza (TT). These endpoints were compared between patients grouped by their gene alterations and treatment. Univariate and multivariate association analyses were performed. Results: The structured note was found to be valuable in capturing relevant discrete clinical outcomes data for detailed analysis. Median OS for the 82 pts was 58 months. 15 pts had insufficient cfDNA to perform the assay and these pts had a significantly longer OS than the 67 pts with sufficient cfDNA (median not reached vs 36 months, p = 0.004). The most commonly altered genes were AR and TP53 with 45% pts having alterations in both genes. Our analysis showed significantly shorter OS with BRAF (24 months, p = 0.008) and NF1 (20 months, p = 0.036) alterations. However, the significance was lost after multiple hypothesis correction. We observed that pts with co-occurrence of AR and BRAF had a significantly shorter OS (18.7 months, p = 0.031). BRCA2 mutations were observed in 9 pts and were associated with a significantly shorter TT (23 vs 38 months, p = 0.022) but lost significance after multiple hypothesis correction. Patients who received Abi followed by Enza had a significantly longer TT compared to pts who received the reverse sequence (38 months vs 23 months, p = 0.02). Conclusions: In this retrospective analysis, we did not identify any significant associations between specific gene alterations and relevant clinical outcomes. We observed a trend of shorter OS with BRAF and NF1 alterations and a shortened OS with co-occurrence of AR and BRAF alterations. These associations will require validation in a larger study. The presence of sufficient DNA to perform the assay was associated with shorter OS. The treatment sequence of Abi followed by Enza showed longer TT than the reverse sequence. The structured note allowed capture of relevant clinical outcomes data and is currently being utilized in a larger prospective genomic study of mCRPC.

Failure rate in the untreated contralateral node negative neck of small lateralized oral cavity cancers: A multi-institutional collaborative study

ObjectivesThe importance of treating the bilateral neck in lateralized small oral cavity squamous cell carcinoma (OCC) is unclear. We sought to define the incidence and predictors of contralateral neck failure (CLF) in patients who underwent unilateral treatment. Materials and methodsWe performed a multi-institutional retrospective study of patients with pathologic T1-T2 (AJCC 7th edition) OCC with clinically node negative contralateral neck who underwent unilateral treatment with primary surgical resection ± adjuvant radiotherapy between 2005 and 2015. Incidence of CLF was estimated using the cumulative incidence method. Clinicopathological factors were analyzed by univariate (UVA) and multivariate analysis (MVA) for possible association with CLF. Kaplan-Meier analysis was used to estimate overall survival (OS). Results176 patients were evaluated with a median of 65.9 months of follow-up. Predominant pathologic T-stage was T1 (68%), 8.5% of patients were N1, 2.8% were N2b. Adjuvant radiotherapy was delivered to 17% of patients. 5-year incidence of CLF was 4.3% (95% CI 1.2–7.4%). Depth of invasion (DOI) > 10 mm and positive ipsilateral neck node were significant predictors for CLF on UVA. DOI > 10 mm remained significant on MVA (HR = 6.7, 95% CI 1.4–32.3, p = 0.02). The 2- and 5-year OS was 90.6% (95% CI 86.2–95.0%) and 80.6% (95% CI 74.5–86.8%), respectively. ConclusionObservation of the clinically node negative contralateral neck in small lateralized OCC can be a suitable management approach in well selected patients, however caution should be applied when DOI upstages small but deeply invasive tumors to T3 on 8th edition AJCC staging.

Microbiota in intestinal digesta of Atlantic salmon (Salmo salar), observed from late freshwater stage until one year in seawater, and effects of functional ingredients: a case study from a commercial sized research site in the Arctic region

BackgroundThe importance of the gut microbiota for health and wellbeing is well established for humans and some land animals. The gut microbiota is supposedly as important for fish, but existing knowledge has many gaps, in particular for fish in the Arctic areas. This study addressed the dynamics of Atlantic salmon digesta-associated gut microbiota assemblage and its associations with host responses from freshwater to seawater life stages under large-scale, commercial conditions in the Arctic region of Norway, and explored the effects of functional ingredients. The microbiota was characterized by 16S rRNA gene sequencing in distal intestinal digesta at four time points: 2 weeks before seawater transfer (in May, FW); 4 weeks after seawater transfer (in June, SW1); in November (SW2), and in April (SW3) the following year. Two series of diets were fed, varying throughout the observation time in nutrient composition according to the requirements of fish, one without (Ref diet), and the other with functional ingredients (Test diet). The functional ingredients, i.e. nucleotides, yeast cell walls, one prebiotic and essential fatty acids, were supplemented as single or mixtures based on the strategies from the feed company.ResultsOverall, the fish showed higher microbial richness and lactic acid bacteria (LAB) abundance after seawater transfer, while Simpson’s diversity decreased throughout the observation period. At SW1, the gut microbiota was slightly different from those at FW, and was dominated by the genera Lactobacillus and Photobacterium. As the fish progressed towards SW2 and SW3, the genera Lactobacillus and Mycoplasma became more prominent, with a corresponding decline in genus Photobacterium. The overall bacterial profiles at these time points showed a clear distinction from those at FW. A significant effect of functional ingredients (a mixture of nucleotides, yeast cell walls and essential fatty acids) was observed at SW2, where Test-fed fish showed lower microbial richness, Shannon’s diversity, and LAB abundance. The multivariate association analysis identified differentially abundant taxa, especially Megasphaera, to be significantly associated with gut immune and barrier gene expressions, and plasma nutrients.ConclusionsThe gut microbiota profile varied during the observation period, and the Mycoplasma became the dominating bacteria with time. Megasphaera abundance was associated with gut health and plasma nutrient biomarkers. Functional ingredients modulated the gut microbiota profile during an important ongrowing stage.

Predictive Physical Manifestations for Progression of Scoliosis in Marfan Syndrome.

A retrospective study of the prospective cohort. To demonstrate the accurate distribution of the severity of scoliosis in patients with Marfan syndrome, and to identify the predictive physical features for progression of scoliosis in Marfan syndrome. To date, no study has unveiled the risk factors for the progression of scoliosis in Marfan syndrome. We retrospectively obtained data from a prospective cohort of the Marfan syndrome clinic at our institute. We enrolled patients whose whole spine radiographs in the standing position were evaluated at the age of 15 or above, from January 2014 to March 2020. The collected variables were physical manifestations defined as in the systemic score of the revised Ghent nosology. We classified the degree of scoliosis into four categories: "not apparent," "mild" (10° ≤ Cobb < 25°), "moderate" (25° ≤ Cobb < 40°), and "severe" (40° ≤ Cobb or surgery conducted). To identify the risk factors for progression of scoliosis in Marfan syndrome, we conducted univariate and multivariate association analyses between severe scoliosis and each physical manifestation. We identified 131 eligible patients (61 men and 70 women) with a mean age of 31.2 years. Scoliosis with a Cobb angle of ≥10° was identified in 116 patients (88.5%). Moderate scoliosis was identified in 33 patients (25.2%) and severe scoliosis in 53 patients (40.5%). The prevalence of each physical manifestation was equivalent to that reported in previous studies. Multivariate logistic regression analysis revealed that female sex (odds ratio, 3.27) and positive wrist sign (4.45) were predictive factors for progression of scoliosis into severe state in patients with Marfan syndrome. The present study demonstrated the accurate distribution of the severity of scoliosis and identified the predictive factors for progression of scoliosis in patients with Marfan syndrome.Level of Evidence: 3.

Differential response of digesta- and mucosa-associated intestinal microbiota to dietary insect meal during the seawater phase of Atlantic salmon

BackgroundIntestinal digesta is commonly used for studying responses of microbiota to dietary shifts, yet evidence is accumulating that it represents an incomplete view of the intestinal microbiota. The present work aims to investigate the differences between digesta- and mucosa-associated intestinal microbiota in Atlantic salmon (Salmo salar) and how they may respond differently to dietary perturbations. In a 16-week seawater feeding trial, Atlantic salmon were fed either a commercially-relevant reference diet or an insect meal diet containing ~ 15% black soldier fly (Hermetia illucens) larvae meal. The digesta- and mucosa-associated distal intestinal microbiota were profiled by 16S rRNA gene sequencing.ResultsRegardless of diet, we observed substantial differences between digesta- and mucosa-associated intestinal microbiota. Microbial richness and diversity were much higher in the digesta than the mucosa. The insect meal diet altered the distal intestinal microbiota resulting in higher microbial richness and diversity. The diet effect, however, depended on the sample origin. Digesta-associated intestinal microbiota showed more pronounced changes than the mucosa-associated microbiota. Multivariate association analyses identified two mucosa-enriched taxa, Brevinema andersonii and Spirochaetaceae, associated with the expression of genes related to immune responses and barrier function in the distal intestine, respectively.ConclusionsOur data show that salmon intestinal digesta and mucosa harbor microbial communities with clear differences. While feeding insects increased microbial richness and diversity in both digesta- and mucosa-associated intestinal microbiota, mucosa-associated intestinal microbiota seems more resilient to variations in the diet composition. To fully unveil the response of intestinal microbiota to dietary changes, concurrent profiling of digesta- and mucosa-associated intestinal microbiota is recommended whenever feasible. Specific taxa enriched in the intestinal mucosa are associated to gene expression related to immune responses and barrier function. Detailed studies are needed on the ecological and functional significance of taxa associated to intestinal microbiota dwelling on the mucosa.

Sun Protection Behaviors and Knowledge in Mountain Marathon Runners and Risk Factors for Sunburn

Background and objectivesThe incidence of skin cancer in our society is growing at an alarming rate due to overexposure to solar UV radiation in recreational and occupational settings. The aim of this study was to evaluate sun exposure and protection attitudes, behaviors, and knowledge among mountain ultramarathon runners and to assess risk factors for sunburn in this population. Material and methodsCross-sectional survey of runners who participated in the Gran Trail Aneto-Posets race in Aragon, Spain. Using a validated questionnaire, we collected data on sociodemographic characteristics, running experience, sunburn in the previous summer, and sun exposure and protection behaviors. We calculated descriptive statistics and performed bivariate and multivariate analyses of associations using history of sunburn as the primary outcome. Statistical significance was set at a P level of less than .05. ResultsWe surveyed 657 runners (72.1% men) with a mean age of 39.71 years; 45.1% reported sunburn in the past year. The most common protective measures used were sunglasses (74.7%), sunscreen (sun protection factor ≥ 15) (61.9%), a hat (52.2%), and other protective clothing (7.4%). Risk factors for sunburn were younger age, low Fitzpatrick skin type (I and II), running for 3 or more hours a day, and staying in the shade as a protective measure. By contrast, protective factors were use of sunscreen and seeking shade rather than sun at midday (P < .001). ConclusionsSunburn is common among long-distance mountain runners, despite what appears to be adequate sun protection knowledge and behaviors. Targeted strategies are needed to improve sun protection behaviors among mountain runners.

Prevalence and factors associated with group B streptococcal colonization in pregnant women

Abstract Objectives: to estimate the prevalence and the factors associated with the colonization by group B streptococcus (GBS) in pregnant women from the urban area attended at health units in a municipality in northeastern Brazil. Methods: it is a cross-sectional study conducted from January 2017 to March 2018. Vagino-rectal swabs were collected from 210 pregnant women between 32 and 40 weeks of gestation. The swabs were seeded on 5% sheep blood agar and on chromogenic agar. For confirmatory identification of GBS, the CAMP test and latex agglutination were used. Descriptive analysis and univariate and multivariate association analysis were performed using a multinomial logistic model. Results: the prevalence of GBS colonization among pregnant women was 18.1% (n = 38), and a statistically significant association (p&lt;0.05) was found for income and parity variables in the group of older women in the univariate analysis, and for skin color, age and parity in the final multivariate analysis. Conclusions: the prevalence of maternal colonization by GBS was similar to that described in other studies. Although some risk factors, such as skin color, age and parity, were associated with colonization, other studies are essential to establish more information on pregnant women more likely to be colonized by GBS.

Multivariate genome wide association and network analysis of subcortical imaging phenotypes in Alzheimer\u2019s disease

BackgroundGenome-wide association studies (GWAS) have identified many individual genes associated with brain imaging quantitative traits (QTs) in Alzheimer’s disease (AD). However single marker level association discovery may not be able to address the underlying biological interactions with disease mechanism.ResultsIn this paper, we used the MGAS (Multivariate Gene-based Association test by extended Simes procedure) tool to perform multivariate GWAS on eight AD-relevant subcortical imaging measures. We conducted multiple iPINBPA (integrative Protein-Interaction-Network-Based Pathway Analysis) network analyses on MGAS findings using protein-protein interaction (PPI) data, and identified five Consensus Modules (CMs) from the PPI network. Functional annotation and network analysis were performed on the identified CMs. The MGAS yielded significant hits within APOE, TOMM40 and APOC1 genes, which were known AD risk factors, as well as a few new genes such as LAMA1, XYLB, HSD17B7P2, and NPEPL1. The identified five CMs were enriched by biological processes related to disorders such as Alzheimer’s disease, Legionellosis, Pertussis, and Serotonergic synapse.ConclusionsThe statistical power of coupling MGAS with iPINBPA was higher than traditional GWAS method, and yielded new findings that were missed by GWAS. This study provides novel insights into the molecular mechanism of Alzheimer’s Disease and will be of value to novel gene discovery and functional genomic studies.

Hábitos y conocimientos sobre fotoprotección y factores de riesgo para quemadura solar en corredores de maratones de montaña

Background and objectivesThe incidence of skin cancer in our society is growing at an alarming rate due to overexposure to solar UV radiation in recreational and occupational settings. The aim of this study was to evaluate sun exposure and protection attitudes, behaviors, and knowledge among mountain ultramarathon runners and to assess risk factors for sunburn in this population. Material and methodsCross-sectional survey of runners who participated in the «Gran Trail Aneto-Posets» race in Aragon, Spain. Using a validated questionnaire, we collected data on sociodemographic characteristics, running experience, sunburn in the previous summer, and sun exposure and protection behaviors. We calculated descriptive statistics and performed bivariate and multivariate analyses of associations using history of sunburn as the primary outcome. Statistical significance was set at a p level of less than 0.05. ResultsWe surveyed 657 runners (72.1% men) with a mean age of 39.71 years; 45.1% reported sunburn in the past year. The most common protective measures used were sunglasses (74.7%), sunscreen (sun protection factor ≥ 15) (61.9%), a hat (52.2%), and other protective clothing (7.4%). Risk factors for sunburn were younger age, low Fitzpatrick skin type (I and II), running for three or more hours a day, and staying in the shade as a protective measure. By contrast, protective factors were use of sunscreen and seeking shade rather than sun at midday (p < 0.001). ConclusionsSunburn is common among long-distance mountain runners, despite what appears to be adequate sun protection knowledge and behaviors. Targeted strategies are needed to improve sun protection behaviors among mountain runners.

S0097 Is Human Immunodeficiency Virus Associated With Pancreatic Cancer?

INTRODUCTION: Pancreatic cancer is the fourth most common cause of cancer-related death in the United States (US). Despite recent advancements, the 5-year survival rate of this highly malignant neoplasm is still 9%. The association of exocrine pancreatic adenocarcinoma (EPA) with infectious etiologies has not been well-explored. In this abstract, we will discuss the association of EPA with HIV in patients with or without AIDS-defining illness. METHODS: We used the 2009 to 2014 nationwide inpatient sample database (NIS) for this study. NIS is the largest publicly available all-payer inpatient database in the US that >7 million hospital stays each year, as a part of the Healthcare Cost and Utilization Project (HCUP). International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) codes for HIV infection (ICD-9 V08, 042 codes) and EPA subtypes (ICD-9 1570, 1571, 1572, 1578, 1579) were obtained. Logistic regression was used to model the association between EPA of the head, body, tail or combined EPA and HIV infection (asymptomatic and with defining illness patients). Participants included in this study were aged 18 years and above. RESULTS: From 2009 to 2014 there were 109,566 patients identified with EPA. The mean age of diagnosis was 67 years. The female to male ratio was 1.46:1 with most of the patients being white (68.5%). Regardless of the specific anatomic site, EPA is significantly lower in patients with asymptomatic HIV infection and HIV defining illness (P < 0.001). Using logistic regression, this negative association is independent of age, sex, race, diabetes, smoking status, obesity, and insurance type (Table 1). When subtypes of EPA based on location were considered, EPA of the head is negatively associated with both asymptomatic HIV infections and HIV defining illnesses, while EPA of the body and tail are not associated with HIV (Table 1). CONCLUSION: Various mechanisms of oncogenic pathogenesis in HIV patients have been proposed, including chronic inflammation and immune system dysregulation. Literature was noted to be sparse in analyzing the relationship between EPA and HIV infection. In this abstract, EPA of the head is less likely in patients with HIV, compared to non-HIV patients. This relationship is unexplained, perhaps due to antiretrovirals use. Further well-designed studies with a good sample size are needed to further explore any existing correlation between these highly malignant diseases.Table 1.: Multivariable analysis of association between HIV infection and pancreatic cancer