Influence of obesity and intra-operative imaging guidance technology on acetabular cup positioning in total hip arthroplasty.

BACKGROUND: Accuracy of acetabular cup positioning during total hip arthroplasty (THA) can be improved with intra-operative imaging but may be influenced by body mass index (BMI). This study assessed the influence of BMI (kg/m2) on cup accuracy when using intra-operative fluoroscopy (IF) alone or supplemented with a commercial product. METHODS: This retrospective review included four consecutive cohorts of patients having undergone anterior approach THA with IF alone (2011-2015), IF and Overlay (2015-2016) (Radlink Inc., Los Angeles, CA), IF and Grid (2017-2018) (HipGrid Drone™, OrthoGrid Systems Inc., Salt Lake City, UT) and IF and Digital (2018-2020) (OrthoGrid Phantom®, OrthoGrid Systems, Inc., Salt Lake City, UT). Component placement accuracy was measured on 6-week post-operative weight bearing radiographs and compared between four BMI patient groups (BMI ≤ 25, 25 < BMI ≤ 30, 30 < BMI ≤ 35, and 35 < BMI). Total fluoroscopy times were also recorded directly from the fluoroscopy unit. RESULTS: Abduction angle significantly increased as BMI increased (p = 0.003) with IF alone but no difference was present in groups with guidance technology. Anteversion was significantly different between BMI groups for IF alone (p = 0.028) and Grid (p = 0.027) but was not different in Overlay (p = 0.107) or Digital (p = 0.210). Fluoroscopy time was significantly different between BMI categories for IF alone (p = 0.005) and Grid (p = 0.018) but was not different in Overlay (p = 0.444) or Digital (p = 0.170). CONCLUSION: Morbid obesity (BMI > 35) increases risk for malpositioning of acetabular cups and increases surgical time with IF alone or the Grid. Additional IF guidance technology (Overlay or Digital) increased cup positioning accuracy without decreasing surgical efficiency.

The Association Between Self-Reported Hearing Loss and Loss of Usual Source of Health Care Among Older Medicare Beneficiaries: Evidence From the National Health and Aging Trends Study.

Background and Objectives: The purpose of the study is to investigate the association of hearing loss (HL) with maintaining a usual source of care (USOC). Research Design and Methods: In this study we implemented a time-to-event analysis using data from the National Health and Aging Trends Study (NHATS), a nationally representative study of older Medicare beneficiaries in the United States. The study sample included 2 114 older adults, aged 65+ years, 58.9% female, 20.4% Black, who reported having a USOC during the baseline round of NHATS and who remained community-dwelling during the 2011-2018 study period. Based on self-report measures at baseline, individuals' hearing status was classified into 3 categories: no HL, treated HL (hearing aids users), and untreated HL (nonhearing aid users who reported having hearing difficulties). Time-to-event was computed as the time elapsed between baseline and the study round in which the respondent first reported no longer having a USOC. Discrete-time proportional hazard models were estimated. Results: In fully adjusted models, untreated HL at baseline was associated with a hazard ratio (HR) for losing one's USOC 1.60 (95% confidence interval: 1.01, 2.56) times higher than that of participants with no HL. We found no HR differences between the treated- and no-HL group. Discussion and Implications: Untreated HL at baseline was associated with a higher probability of losing one's USOC over time. Noninvasive interventions such as hearing aids may be beneficial for maintaining a USOC.

Fecal and Tissue Microbiota Are Associated with Tumor T-Cell Infiltration and Mesenteric Lymph Node Involvement in Colorectal Cancer.

Colorectal cancer (CRC) is associated with alterations of the fecal and tissue-associated microbiome. Preclinical models support a pathogenic role of the microbiome in CRC, including in promoting metastasis and modulating antitumor immune responses. To investigate whether the microbiome is associated with lymph node metastasis and T cell infiltration in human CRC, we performed 16S rRNA gene sequencing of feces, tumor core, tumor surface, and healthy adjacent tissue collected from 34 CRC patients undergoing surgery (28 fecal samples and 39 tissue samples). Tissue microbiome profiles-including increased Fusobacterium-were significantly associated with mesenteric lymph node (MLN) involvement. Fecal microbes were also associated with MLN involvement and accurately classified CRC patients into those with or without MLN involvement. Tumor T cell infiltration was assessed by immunohistochemical staining of CD3 and CD8 in tumor tissue sections. Tumor core microbiota, including members of the Blautia and Faecalibacterium genera, were significantly associated with tumor T cell infiltration. Abundance of specific fecal microbes including a member of the Roseburia genus predicted high vs. low total and cytotoxic T cell infiltration in random forests classifiers. These findings support a link between the microbiome and antitumor immune responses that may influence prognosis of locally advanced CRC.

The Ocular Microbiome Is Altered by Sampling Modality and Age.

Background: Studies of the ocular microbiome have used a variety of sampling techniques, but no study has directly compared different sampling methods applied to the same eyes to one another or to a reference standard of corneal epithelial biopsy. We addressed this lack by comparing the microbiome from three conjunctival swabs with those of corneal epithelial biopsy. Methods: Twelve eyes (11 patients) were swabbed by calcium alginate swab, cotton-tipped applicator, and Weck-Cel cellulose sponge before a corneal epithelial biopsy (48 samples). We then performed 16S rRNA gene sequencing and universal 16S rRNA gene real-time polymerase chain reaction. Negative/blank controls were used to eliminate contaminants. An analysis was performed to examine the concordance of the three swab types to corneal epithelial biopsy. The effect of patient age on the ocular microbiome as determined by epithelial biopsy was also examined. Results: The ocular microbiome from corneal epithelial biopsies consisted of 31 genera with a relative abundance of 1% or more, including Weisella, Corynebacterium, and Pseudomonas. Of the three swab types, Weck-Cel differed the most from corneal biopsies based on beta-diversity analysis. Cotton swabs were unable to capture the Bacteroides population seen on epithelial biopsy. Therefore, calcium alginate swabs seemed to be the closest to epithelial biopsies. Older patients (≥65 years old) had higher alpha diversity (P < 0.05) than younger patients. Differential abundance testing showed that there were 18 genera that were differentially abundant between the two age groups, including Streptococcus and eight members of the Proteobacteria phylum. Conclusions: We demonstrate that ocular sampling method and patient age can greatly affect the outcome of sequencing-based analysis of the ocular microbiome. Translational Relevance: By understanding the impact of different sampling methods on the results obtained from the ocular surface microbiome, future research on the topic will be more reproducible, leading to a better understanding of ocular surface microbiome in health and disease.

Variables Associated with Coronavirus Disease 2019 Vaccine Hesitancy Amongst Patients with Neurological Disorders.

INTRODUCTION: Given that the success of vaccines against coronavirus disease 2019 (COVID-19) relies on herd immunity, identifying patients at risk for vaccine hesitancy is imperative-particularly for those at high risk for severe COVID-19 (i.e., minorities and patients with neurological disorders). METHODS: Among patients from a large neuroscience institute in Hawaii, vaccine hesitancy was investigated in relation to over 30 sociodemographic variables and medical comorbidities, via a telephone quality improvement survey conducted between 23 January 2021 and 13 February 2021. RESULTS: Vaccine willingness (n = 363) was 81.3%. Univariate analysis identified that the odds of vaccine acceptance reduced for patients who do not regard COVID-19 as a severe illness, are of younger age, have a lower Charlson Comorbidity Index, use illicit drugs, or carry Medicaid insurance. Multivariable logistic regression identified the best predictors of vaccine hesitancy to be: social media use to obtain COVID-19 information, concerns regarding vaccine safety, self-perception of a preexisting medical condition contraindicated with vaccination, not having received the annual influenza vaccine, having some high school education only, being a current smoker, and not having a prior cerebrovascular accident. Unique amongst males, a conservative political view strongly predicted vaccine hesitancy. Specifically for Asians, a higher body mass index, while for Native Hawaiians and other Pacific Islanders (NHPI), a positive depression screen, both reduced the odds of vaccine acceptance. CONCLUSION: Upon identifying the variables associated with vaccine hesitancy amongst patients with neurological disorders, our clinic is now able to efficiently provide ancillary COVID-19 education to sub-populations at risk for vaccine hesitancy. While our results may be limited to the sub-population of patients with neurological disorders, the findings nonetheless provide valuable insight to understanding vaccine hesitancy.

The Intestinal Microbiome Predicts Weight Loss on a Calorie-Restricted Diet and Is Associated With Improved Hepatic Steatosis.

Background: The microbiome has been shown in pre-clinical and epidemiological studies to be important in both the development and treatment of obesity and metabolic associated fatty liver disease (MAFLD). However, few studies have examined the role of the microbiome in the clinical response to calorie restriction. To explore this area, we performed a prospective study examining the association of the intestinal microbiome with weight loss and change in hepatic steatosis on a calorie-restricted diet. Methods: A prospective dietary intervention study of 80 overweight and obese participants was performed at the Greater West Los Angeles Veterans Affair Hospital. Patients were placed on a macronutrient standardized diet for 16 weeks, including 14 weeks of calorie restriction (500 calorie deficit). Body composition analysis by impedance, plasma lipid measurements, and ultrasound elastography to measure hepatic steatosis were performed at baseline and week 16. Intestinal microbiome composition was assessed using 16S rRNA gene sequencing. A per protocol analysis was performed on all subjects completing the trial (n = 46). Results: Study completers showed significant reduction in weight, body mass index, total cholesterol, low density lipoprotein, and triglyceride. Subjects who lost at least 5% of their body weight had significantly greater reduction in serum triglyceride and hepatic steatosis than those with <5% body weight loss. Enterococcus and Klebsiella were reduced at the end of the trial while Coprococcus and Collinsella were increased. There were also significant baseline microbiome differences between patients who had at least 5% weight loss as compared to those that did not. Lachnoclostridium was positively associated with hepatic steatosis and Actinomyces was positively associated with hepatic steatosis and weight. Baseline microbiome profiles were able to predict which patients lost at least 5% of their body weight with an AUROC of 0.80. Conclusion: Calorie restriction alters the intestinal microbiome and improves hepatic steatosis in those who experience significant weight loss. Baseline microbiome differences predict weight loss on a calorie-restricted diet and are associated with improvement in hepatic steatosis, suggesting a role of the gut microbiome in mediating the clinical response to calorie restriction.

Specimen Collection and Analysis of the Duodenal Microbiome.

Shifts in the microbiome have been correlated with the physiology and pathophysiology of many organ systems both in humans and in mouse models. The gut microbiome has been typically studied through fecal specimen collections. The ease of obtaining fecal samples has resulted in many studies that have revealed information concerning the distal luminal gastrointestinal tract. However, few studies have addressed the importance of the microbiome in the proximal gut. Given that the duodenum is a major site for digestion and absorption, its microbiome is relevant to nutrition and liver disease and warrants further investigation. Here we detail a novel method for sampling the proximal luminal and mucosal gut microbiome in human subjects undergoing upper endoscopy by obtaining duodenal aspirate and biopsies. Specimen procurement is facile and unaffected by artifacts such as patient preparatory adherence, as might be the case in obtaining colonic samples during colonoscopy. The preliminary results show that the luminal and mucosal microbiomes differ significantly, which is likely related to environmental conditions and barrier functions. Therefore, a combination of duodenal aspirate and biopsies reveal a more comprehensive picture of the microbiome in the duodenum. Biopsies are obtained from the descending and horizontal segments of the duodenum, which are anatomically close to the liver and biliary tree. This is important in studying the role of bile acid biology and the gut-liver axis in liver disease. Biopsies and aspirate can be used for 16S ribosomal RNA sequencing, metabolomics, and other similar applications.

Gut microbiome profiles associated with steatosis severity in metabolic associated fatty liver disease.

Aim: The microbiome has been shown to be pivotal in the development of metabolic associated fatty liver disease (MAFLD). Few have examined the relationship of the microbiome specifically with steatosis grade. Therefore, our aim was to characterize the association of the microbiome with MAFLD steatosis severity while adjusting for metabolic comorbidities including diabetes. Methods: We enrolled patients with MAFLD at the West Los Angeles Veterans Affair Hospital. All patients underwent ultrasound elastography, fasting serum collection, and fecal sampling for 16S sequencing. We examined the associations of microbial diversity and composition with advanced steatosis, defined as a CAP score of ≥ 300 dB/m, with or without the presence of metabolic comorbidities. Results: Seventy-five patients were enrolled. African American were less likely to have advanced steatosis than either Hispanics or Whites (P = 0.001). Patients with more advanced steatosis had higher fasting serum triglyceride (192.6 ± 157.1 mg/dL vs. 122.5 ± 57.4 mg/dL), HbA1c (6.7% ± 1.4% vs. 6.1% ± 0.8%), transaminases, and were more likely to have metabolic syndrome (52.4% vs. 24.2%, P = 0.02). Advanced steatosis and diabetes were associated with altered microbial composition. Bacteroides was negatively associated with advanced steatosis while Megasphaera was positively associated with steatosis. Akkermansia was negatively associated with diabetes, while Anaerostipes and Parabacteroides were positively associated with diabetes. Conclusion: Diabetes and metabolic syndrome are associated with hepatic steatosis severity in MAFLD patients and both advanced steatosis and comorbid diabetes are independently associated with microbiome changes. These results provide insight into the role of the gut microbiome in MAFLD associated with metabolic syndrome.

A High Protein Calorie Restriction Diet Alters the Gut Microbiome in Obesity.

BACKGROUND: High protein calorie restriction diets have shown clinical efficacy for obesity, but the mechanisms are not fully known. The intestinal microbiome is a mediator of obesity and preclinical data support an effect of high protein diet (HPD) on the gut microbiome of obesity, but there are few studies in humans. METHODS: To address this, we conducted a dietary intervention trial of 80 overweight and obese subjects who were randomized to a calorie-restricted high protein diet (HPD) (30% calorie intake) or calorie-restricted normal protein diet (NPD) (15%) for 8 weeks. Baseline dietary intake patterns were assessed by the Diet History Questionnaire III. Longitudinal fecal sampling was performed at baseline, week 1, week 2, week 4, week 6, and week 8, for a total of 365 samples. Intestinal microbiome composition was assessed by 16S rRNA gene sequencing. RESULTS: At baseline, microbial composition was associated with fiber and protein intake. Subjects on the HPD showed a significant increase in microbial diversity as measured by the Shannon index compared to those on the NPD. The HPD was also associated with significant differences in microbial composition after treatment compared to the NPD. Both diets induced taxonomic shifts compared to baseline, including enrichment of Akkermansia spp. and Bifidobacterium spp. and depletion of Prevotella spp. Conclusion: These findings provide evidence that weight loss diets alter the gut microbiome in obesity and suggest differential effects of HPDs compared to NPDs which may influence the clinical response to HPD.

A Microbial Signature Identifies Advanced Fibrosis in Patients with Chronic Liver Disease Mainly Due to NAFLD.

The presence of advanced fibrosis is an important measure of the severity of chronic liver disease. Prior works that have examined the gut microbiome as a novel biomarker for advanced fibrosis have only examined patients with nonalcoholic fatty liver disease. Therefore, our goal was to examine the gut microbiome across varying etiologies of liver disease to create a predictive model for liver fibrosis based upon a microbial signature. Stool samples were obtained from patients with chronic liver disease (n = 50) undergoing FibroScan (ultrasound elastography) at the VA Greater Los Angeles Healthcare System. Healthy control patients (n = 25) were also recruited as a reference population. Fecal samples underwent 16S ribosomal RNA sequencing. Using differentially abundant microbes, a random forest classifier model was created to distinguish advanced fibrosis from mild/moderate fibrosis. The findings were then validated in a separate cohort of chronic liver disease patients (n = 37). Etiologies for liver disease included non-alcoholic liver disease (58.0%), hepatitis C (26.0%), hepatitis B (10.0%), and alcohol (6.0%). Microbiome composition was distinct in liver patients with advanced fibrosis compared to those with minimal fibrosis and healthy controls (p = 0.003). In multivariate negative binomial modeling, 26 bacterial taxa were differentially abundant in patients with advanced fibrosis as compared to those with minimal/moderate fibrosis (q-value < 0.05). A random forests classifier based on these taxa had an AUROC of 0.90 to predict advanced fibrosis. Prevotella copri, which was enriched in patients with advanced fibrosis, was the most strongly predictive microbe in the classifier. The classifier had an AUROC of 0.82 for advanced fibrosis in the validation cohort and Prevotella copri remained the strongest predictive microbe for advanced fibrosis. There is a distinct microbial signature for patients with advanced fibrosis independent of liver disease etiology and other comorbidities. These results suggest that microbial profiles can be used as a non-invasive marker for advanced fibrosis and support the hypothesis that microbes and their metabolites contribute to hepatic fibrosis.

Machine Learning-based Development and Validation of a Scoring System for Screening High-Risk Esophageal Varices.

BACKGROUND & AIMS: Many patients with cirrhosis who undergo esophagogastroduodenoscopy (EGD) screening for esophageal varices (EVs) are found to have no or only small EVs. Endoscopic screening for EVs is therefore a potentially deferrable procedure that increases patient risk and healthcare cost. We developed and validated a scoring system, based on readily-available data, to reliably identify patients with EVs that need treatment. METHODS: We collected data from 238 patients with cirrhosis undergoing screening EGD from January 2016 through December 2017 at 3 separate hospitals in Los Angeles (training cohort). We abstracted data on patient sex, age, race/ethnicity, platelet counts, and levels of hemoglobin, serum sodium, aspartate aminotransferase, alanine aminotransferase, total bilirubin, international normalized ratio, albumin, urea nitrogen, and creatinine. We also included etiology of cirrhosis, presence of ascites, and presence of hepatic encephalopathy. We used a random forest algorithm to identify factors significantly associated with the presence of EVs and varices needing treatment (VNT) and calculated area under the receiver operating characteristic curve (AUROC). We called the resulting formula the EVendo score. We tested the accuracy of EVendo in a prospective study of 109 patients undergoing screening EGDs at the same medical centers from January 2018 through December 2018 (validation cohort). RESULTS: We developed an algorithm that identified patients with EVs and VNT based on international normalized ratio, level of aspartate aminotransferase, platelet counts, urea nitrogen, hemoglobin, and presence of ascites. The EVendo score identified patients with EVs in the training set with an AUROC of 0.84, patients with EVs in the validation set with and AUROC of 0.82, and EVs in patients with cirrhosis Child-Turcotte-Pugh class A (n = 235) with an AUROC of 0.81. The score identified patients with VNT in the training set with an AUROC of 0.74, VNT in the validation set with and AUROC of 0.75, and VNT in patients with cirrhosis Child-Turcotte-Pugh class A with and AUROC of 0.75. An EVendo score below 3.90 would have spared 30.5% patients from EGDs, missing only 2.8% of VNT. The same cutoff would have spared 40.0% of patients with Child-Turcotte-Pugh class A cirrhosis from EGDs, missing only 1.1% of VNT. CONCLUSIONS: We algorithmically developed a formula, called the EVendo score, that can be used to predict EVs and VNT based on readily available data in patients with cirrhosis. This score could help patients at low risk for VNT avoid unnecessary EGDs.