The use of amniotic tissue-derived products in orthopedic surgery: A narrative review.

Amniotic-derived products have been used for decades in various medical subspecialties and have proven to be a safe method of allograft tissue transplantation. These products have shown promising preclinical and early clinical results in the treatment of tendon/ligament injuries, cartilage defects, and osteoarthritis. The therapeutic benefits of amniotic-derived products are likely due to intrinsic properties, such as their structure as an extracellular matrix and concentration of growth factors, as well as anti-inflammatory, antifibrotic, and antimicrobial molecules. We performed a narrative review, evaluating the pre-clinical and clinical use of amniotic-derived products in musculoskeletal injuries such as osteoarthritis, Achilles tendinopathy, plantar fasciitis, lateral epicondylitis, chronic stenosing tenosynovitis, and nerve, cartilage and tendon repair or reconstruction, along with fracture healing treatment. In vitro and pre-clinical studies using amniotic-derived products for orthopedic treatments have shown promising results and provide the foundation for further human trials to be conducted. With the rise of commercially available biologics, incorporating amniotic products into orthopedic practice is becoming more accessible, while further studies investigating long-term outcomes and potential adverse events are necessary.

Artificial Intelligence for Diagnosis in Otologic Patients: Is It Ready to Be Your Doctor?

OBJECTIVE: Investigate the precision of language-model artificial intelligence (AI) in diagnosing conditions by contrasting its predictions with diagnoses made by board-certified otologic/neurotologic surgeons using patient-described symptoms. STUDY DESIGN: Prospective cohort study. SETTING: Tertiary care center. PATIENTS: One hundred adults participated in the study. These included new patients or established patients returning with new symptoms. Individuals were excluded if they could not provide a written description of their symptoms. INTERVENTIONS: Summaries of the patient's symptoms were supplied to three publicly available AI platforms: Chat GPT 4.0, Google Bard, and WebMD "Symptom Checker." MAIN OUTCOME MEASURES: This study evaluates the accuracy of three distinct AI platforms in diagnosing otologic conditions by comparing AI results with the diagnosis determined by a neurotologist with the same information provided to the AI platforms and again after a complete history and physical examination. RESULTS: The study includes 100 patients (52 men and 48 women; average age of 59.2 yr). Fleiss' kappa between AI and the physician is -0.103 (p < 0.01). The chi-squared test between AI and the physician is χ2 = 12.95 (df = 2; p < 0.001). Fleiss' kappa between AI models is 0.409. Diagnostic accuracies are 22.45, 12.24, and 5.10% for ChatGPT 4.0, Google Bard, and WebMD, respectively. CONCLUSIONS: Contemporary language-model AI platforms can generate extensive differential diagnoses with limited data input. However, doctors can refine these diagnoses through focused history-taking, physical examinations, and clinical experience-skills that current AI platforms lack.

"Does an Additional Advanced Degree Influence Career Trajectory as a Shoulder and Elbow Surgeon?"

BACKGROUND: As orthopedic surgery becomes increasingly competitive, orthopedic surgeons are now pursuing advanced degrees more frequently to enhance their resumes or gain additional expertise. The specific impact of this additional training and education on a surgeon's career trajectory is not well defined. The purpose of this study was to understand the impact of an advanced degree on the academic career of orthopedic shoulder and elbow surgeons. METHODS: Orthopedic shoulder and elbow fellowship-trained surgeons were identified using the directory listed on the American Shoulder and Elbow Surgeons website. Demographics, education, and current professional roles were obtained. Research productivity was obtained using SCOPUS and Google Scholar. Advanced degrees were defined as those additional to the primary medical degree (Doctor of Medicine [MD] or Doctor of Osteopathic Medicine [DO]). Outcome measures collected included timing of advanced degree obtainment, current academic and leadership roles, leadership on journal editorial boards, and research productivity. Statistical analysis was performed using the chi-square test and Mann-Whitney U test to determine the association of advanced degrees on outcome measures. RESULTS: In total, 893 orthopedic shoulder and elbow surgeons were identified, of whom 129 had advanced degrees. Most common advanced degrees included Master of Science (MS/MSc; 43%), Master of Business Administration (MBA; 23%), and Doctor of Philosophy (PhD; 13%). The most common period of degree obtainment was before medical school (35%) with the least common times being after medical school/before residency (0.9%) and between residency and fellowship training (0.9%). Surgeons who held advanced degrees demonstrated greater research productivity, with a higher h-index (p < 0.001), a greater number of citations (p < 0.001), and more publications (p < 0.001). Of the 523 shoulder and elbow surgeons who worked at an academic institution, those holding advanced degrees were more likely to serve as orthopedic department chair (p < 0.001) and serve an editorial board position (< 0.001). CONCLUSION: This study found that having an advanced degree as an orthopedic shoulder and elbow surgeon was linked to higher research impact and productivity and an increased likelihood of becoming a department chair and holding an editorial position. These significant findings can help future trainees and department leadership in understanding the importance and impact of additional training on career trajectories for academic faculty.

Physician perspectives of Helicobacter pylori diagnostic and treatment practices in Canada: results of a Canadian survey.

BACKGROUND: Helicobacter pylori infection is prevalent worldwide and can lead to peptic ulcer disease (PUD) and gastric cancer. Effective diagnosis and treatment of H. pylori infection by gastroenterologists and family physicians is crucial. However, there are differing views on optimal diagnosis and treatment. The objective of this study is to understand the impressions of Canadian physicians regarding H. pylori diagnosis and treatment and whether impressions differ between gastroenterologists and family physicians. A second objective is to understand physician perspectives on rising antibiotic resistance and how that guides empiric management. METHODS: A survey facilitated via REDCap was administered to Canadian gastroenterologists and family physicians. A total of 105 participants completed the survey, including 43 gastroenterologists and 62 family physicians. Gastroenterologists were recruited from across the country and family physicians were recruited from Manitoba. RESULTS: For diagnosis of H. pylori, 67% of gastroenterologists reported endoscopic biopsies for histology assessment as most common and 73% of family physicians reported serology as their main diagnostic test. While nearly all gastroenterologists believed antibiotic resistance to be a problem, nearly one quarter of family physicians did not believe it was a problem. CONCLUSIONS: There is variability in practices among both gastroenterologists and family physicians regarding diagnosis of H. pylori infection. There was consensus that local antibiotic resistance patterns should guide management. If known, the degree and patterns of antibiotic resistance could bring a more uniform consensus to H. pylori management. Greater education of physicians, especially family physicians regarding management of H pylori is needed.

A vessel sealing device and an ultrasonic dissector are equally effective and safe for single port laparoscopic ovariectomy in dogs.

OBJECTIVE: To evaluate ovary removal surgery times and intraoperative complication rates between a 5-mm Sonicision cordless ultrasonic dissector (SCUD) and 5-mm vessel sealing device (VSD) for laparoscopic ovariectomy in dogs. ANIMALS: Client-owned, intact female dogs (n = 10) presented for elective laparoscopic ovariectomy. METHODS: In each dog, 1 ovarian pedicle was randomly assigned to the SCUD group and 1 to the VSD group. In the SCUD group (n = 10), the ovariectomy was performed using the SCUD device; the ovariectomy in the VSD group (10) was performed using a VSD. The number of applications of each device during ovariectomy, surgery time required for each ovary removal, total surgery duration, ovarian pedicle fat score, and intraoperative complications were recorded. RESULTS: Both left and right ovaries had median pedicle fat scores of 2 (range, 1 to 3). To complete an ovariectomy, the median number of SCUD applications was 9 (range, 7 to 13) times; the VSD had a median of 10 (range, 5 to 18) times (P = .98). Median surgery times for the removal of 1 ovary with the SCUD and VSD were 96 seconds (range, 45 to 417 seconds) and 110 seconds (range, 42 to 164 seconds), respectively (P = 1). No intraoperative complications were associated with either device. Therefore, the VSD was not required for rescue in the SCUD group, and no conversions to open ovariectomy were necessary. CLINICAL RELEVANCE: A standard approach laparoscopic ovariectomy performed with the SCUD was successful in our population of dogs, making the 5-mm SCUD safe for laparoscopic ovariectomy in healthy dogs, which provides a more affordable option for practitioners and clients.

Use of a taxon-specific reference database for accurate metagenomics-based pathogen detection of Listeria monocytogenes in turkey deli meat and spinach.

BACKGROUND: The reliability of culture-independent pathogen detection in foods using metagenomics is contingent on the quality and composition of the reference database. The inclusion of microbial sequences from a diverse representation of taxonomies in universal reference databases is recommended to maximize classification precision for pathogen detection. However, these sizable databases have high memory requirements that may be out of reach for some users. In this study, we aimed to assess the performance of a foodborne pathogen (FBP)-specific reference database (taxon-specific) relative to a universal reference database (taxon-agnostic). We tested our FBP-specific reference database's performance for detecting Listeria monocytogenes in two complex food matrices-ready-to-eat (RTE) turkey deli meat and prepackaged spinach-using three popular read-based DNA-to-DNA metagenomic classifiers: Centrifuge, Kraken 2 and KrakenUniq. RESULTS: In silico host sequence removal led to substantially fewer false positive (FP) classifications and higher classification precision in RTE turkey deli meat datasets using the FBP-specific reference database. No considerable improvement in classification precision was observed following host filtering for prepackaged spinach datasets and was likely a consequence of a higher microbe-to-host sequence ratio. All datasets classified with Centrifuge using the FBP-specific reference database had the lowest classification precision compared to Kraken 2 or KrakenUniq. When a confidence-scoring threshold was applied, a nearly equivalent precision to the universal reference database was achieved for Kraken 2 and KrakenUniq. Recall was high for both reference databases across all datasets and classifiers. Substantially fewer computational resources were required for metagenomics-based detection of L. monocytogenes using the FBP-specific reference database, especially when combined with Kraken 2. CONCLUSIONS: A universal (taxon-agnostic) reference database is not essential for accurate and reliable metagenomics-based pathogen detection of L. monocytogenes in complex food matrices. Equivalent classification performance can be achieved using a taxon-specific reference database when the appropriate quality control measures, classification software, and analysis parameters are applied. This approach is less computationally demanding and more attainable for the broader scientific and food safety communities.

Wound swab quality grading is dependent on Gram smear screening approach.

Superficial skin swab collections are inherently low-quality and may be of little clinical value due to their poor sensitivity and specificity. Clinical microbiology laboratories can use Gram smears to screen and differentiate higher and lower quality specimens to direct the extent of potential pathogen work up, including antimicrobial susceptibility testing (AST). We compared the impact of two different smear grading approaches to our current reporting practices for superficial wound swab cultures. Two variations of the Q score methodology (low power under 10X (QS10) and high power under 100X (QS100) were compared to our existing oil immersion method (OM100) (100X). We further evaluated the QS100 method by scoring superficial swab smears previously screened by OM100 from cultures submitted between November 2018 and December 2019. No significant difference in the number of low-quality specimens (N = 50) was identified by QS10 or QS100 grading (N = 9; 18%; N = 8; 16% respectively). Among 968 additional QS100 screened smears, 67 (6.9%) low quality swabs were identified and 7.4% fewer organisms (76/1020 organisms) would require reporting with AST. Implementing the Q score for superficial wound swab cultures would provide minimal improvements in their clinical relevance, laboratory quality and efficiency in our laboratory due to the low number of poor-quality swabs received.

The metabolic potential of the paediatric-onset multiple sclerosis gut microbiome.

BACKGROUND: The aim of this study was to examine the gut microbiome's metabolic potential in paediatric-onset MS patients (symptom onset <18 years). METHODS: We included 17 MS participants and 20 controls similar for sex, age, race, and stool consistency from the Canadian Paediatric Demyelinating Disease Network study. Stool-derived gut metagenome gene abundances were used to estimate relative abundances and turnover scores of individual microbial metabolites and the composition and diversity of carbohydrate-active enzymes (CAZymes). MS participants and controls were compared using the Wilcoxon rank-sum test, as were the disease-modifying drug (DMD) exposed and naïve MS participants. RESULTS: The median age(s) at MS symptom onset=16.1 years (interquartile range [IQR]=1.7), and at stool sample procurement=16.9/15.8 years (IQR=2.0/1.4), for the MS participants/controls. Most MS and control participants were girls (80-82%). Five (29%) of the MS participants had never been exposed to a DMD pre-stool sample and 12 (71%) had (7 to beta-interferon and 5 glatiramer acetate). While the relative abundance of metabolites did not differ between MS participants and controls, turnover scores did. MS participants had a greater potential to metabolize lipopolysaccharides than controls (score difference=1.6E-04, p = 0.034) but lower potential to metabolize peptidoglycan molecules and starch (score differences<2.2E-02, p<0.040). Further, although CAZymes diversity did not differ (p>0.050), starch-degrading subfamilies were underrepresented in MS participants versus controls (relative abundance differences >-0.34, p<0.040) and in the DMD exposed verses DMD naïve MS participants (relative abundance differences>-0.20, p<0.049). CONCLUSION: Paediatric-onset MS participants had an altered gut microbiome-related metabolic potential compared to controls, including higher breakdown of lipopolysaccharide molecules, but lower resistant starch metabolism.

Stability of the gut microbiota in persons with paediatric-onset multiple sclerosis and related demyelinating diseases.

OBJECTIVE: Examine if the gut microbiota composition changes across repeated samples in paediatric-onset multiple sclerosis (MS) or monophasic-acquired demyelinating syndromes (monoADS). METHODS: A total of 36 individuals (18 MS/18 monoADS) with ⩾2 stool samples were included. Stool sample-derived DNA was sequenced. Alpha/beta diversities and genus-level taxa were analysed. RESULTS: Mean ages at first sample procurement (MS/monoADS) = 18.0/13.8 years. Median time (months) between first/second samples = 11.2 and second/third = 10.3. Alpha/beta diversities did not differ between stool samples (p > 0.09), while one genus - Solobacterium did (p = 0.001). CONCLUSIONS: The gut microbiota composition in paediatric-onset MS and monoADS exhibited stability, suggesting that single stool sample procurement is a reasonable first approach.

Clinical Metagenomics Is Increasingly Accurate and Affordable to Detect Enteric Bacterial Pathogens in Stool.

Stool culture is the gold standard method to diagnose enteric bacterial infections; however, many clinical laboratories are transitioning to syndromic multiplex PCR panels. PCR is rapid, accurate, and affordable, yet does not yield subtyping information critical for foodborne disease surveillance. A metagenomics-based stool testing approach could simultaneously provide diagnostic and public health information. Here, we evaluated shotgun metagenomics to assess the detection of common enteric bacterial pathogens in stool. We sequenced 304 stool specimens from 285 patients alongside routine diagnostic testing for Salmonella spp., Campylobacter spp., Shigella spp., and shiga-toxin producing Escherichia coli. Five analytical approaches were assessed for pathogen detection: microbiome profiling, Kraken2, MetaPhlAn, SRST2, and KAT-SECT. Among analysis tools and databases compared, KAT-SECT analysis provided the best sensitivity and specificity for all pathogens tested compared to culture (91.2% and 96.2%, respectively). Where metagenomics detected a pathogen in culture-negative specimens, standard PCR was positive 85% of the time. The cost of metagenomics is approaching the current combined cost of PCR, reflex culture, and whole genome sequencing for pathogen detection and subtyping. As cost, speed, and analytics for single-approach metagenomics improve, it may be more routinely applied in clinical and public health laboratories.

Real-Time RT-PCR Allelic Discrimination Assay for Detection of N501Y Mutation in the Spike Protein of SARS-CoV-2 Associated with B.1.1.7 Variant of Concern.

The N501Y amino acid mutation caused by a single point substitution A23063T in the spike gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is possessed by three variants of concern (VOCs), B.1.1.7, B.1.351, and P.1. A rapid screening tool using this mutation is important for surveillance during the coronavirus disease 2019 (COVID-19) pandemic. We developed and validated a single nucleotide polymorphism real-time reverse transcription PCR assay using allelic discrimination of the spike gene N501Y mutation to screen for potential variants of concern and differentiate them from SARS-CoV-2 lineages without the N501Y mutation. A total of 160 clinical specimens positive for SARS-CoV-2 were characterized as mutant (N501Y) or N501 wild type by Sanger sequencing and were subsequently tested with the N501Y single nucleotide polymorphism real-time reverse transcriptase PCR assay. Our assay, compared to Sanger sequencing for single nucleotide polymorphism detection, demonstrated positive percent agreement of 100% for all 57 specimens displaying the N501Y mutation, which were confirmed by Sanger sequencing to be typed as A23063T, including one specimen with mixed signal for wild type and mutant. Negative percent agreement was 100% in all 103 specimens typed as N501 wild type, with A23063 identified as wild type by Sanger sequencing. The identification of circulating SARS-CoV-2 lineages carrying an N501Y mutation is critical for surveillance purposes. Current identification methods rely primarily on Sanger sequencing or whole-genome sequencing, which are time consuming, labor intensive, and costly. The assay described herein is an efficient tool for high-volume specimen screening for SARS-CoV-2 VOCs and for selecting specimens for confirmatory Sanger or whole-genome sequencing. IMPORTANCE During the coronavirus disease 2019 (COVID-19) pandemic, several variants of concern (VOCs) have been detected, for example, B.1.1.7, B.1.351, P.1, and B.1.617.2. The VOCs pose a threat to public health efforts to control the spread of the virus. As such, surveillance and monitoring of these VOCs is of the utmost importance. Our real-time RT-PCR assay helps with surveillance by providing an easy method to quickly survey SARS-CoV-2 specimens for VOCs carrying the N501Y single nucleotide polymorphism (SNP). Samples that test positive for the N501Y mutation in the spike gene with our assay can be sequenced to identify the lineage. Thus, our assay helps to focus surveillance efforts and decrease turnaround times.

Colorectal Cancer Screening in Inflammatory Bowel Diseases-Can Characterization of GI Microbiome Signatures Enhance Neoplasia Detection?

Current noninvasive methods for colorectal cancer (CRC) screening are not optimized for persons with inflammatory bowel diseases (IBDs), requiring patients to undergo frequent interval screening via colonoscopy. Although colonoscopy-based screening reduces CRC incidence in IBD patients, rates of interval CRC remain relatively high, highlighting the need for more targeted approaches. In recent years, the discovery of disease-specific microbiome signatures for both IBD and CRC has begun to emerge, suggesting that stool-based biomarker detection using metagenomics and other culture-independent technologies may be useful for personalized, early, noninvasive CRC screening in IBD patients. Here we discuss the utility of the stool microbiome as a noninvasive CRC screening tool. Comparing the performance of multiple microbiome-based CRC classifiers, including several multi-cohort meta-analyses, we find that noninvasive detection of colorectal adenomas and carcinomas from microbial biomarkers is an active area of study with promising early results.

Impact of coronavirus disease 2019 (COVID-19) pre-test probability on positive predictive value of high cycle threshold severe acute respiratory coronavirus virus 2 (SARS-CoV-2) real-time reverse transcription polymerase chain reaction (RT-PCR) test results.

OBJECTIVES: Performance characteristics of SARS-CoV-2 nucleic acid detection assays are understudied within contexts of low pre-test probability, including screening asymptomatic persons without epidemiological links to confirmed cases, or asymptomatic surveillance testing. SARS-CoV-2 detection without symptoms may represent presymptomatic or asymptomatic infection, resolved infection with persistent RNA shedding, or a false-positive test. This study assessed the positive predictive value of SARS-CoV-2 real-time reverse transcription polymerase chain reaction (rRT-PCR) assays by retesting positive specimens from 5 pre-test probability groups ranging from high to low with an alternate assay. METHODS: In total, 122 rRT-PCR positive specimens collected from unique patients between March and July 2020 were retested using a laboratory-developed nested RT-PCR assay targeting the RNA-dependent RNA polymerase (RdRp) gene followed by Sanger sequencing. RESULTS: Significantly fewer (15.6%) positive results in the lowest pre-test probability group (facilities with institution-wide screening having ≤3 positive asymptomatic cases) were reproduced with the nested RdRp gene RT-PCR assay than in each of the 4 groups with higher pre-test probability (individual group range, 50.0%-85.0%). CONCLUSIONS: Large-scale SARS-CoV-2 screening testing initiatives among low pre-test probability populations should be evaluated thoroughly prior to implementation given the risk of false-positive results and consequent potential for harm at the individual and population level.

Metagenomic Analysis of the Pediatric-Onset Multiple Sclerosis Gut Microbiome.

BACKGROUND AND OBJECTIVES: Little is known of the functional potential of the gut microbiome in pediatric-onset multiple sclerosis (MS). We performed metagenomic analyses using stool samples from individuals with pediatric-onset MS and unaffected controls. METHODS: Persons ≤21 years old enrolled in the Canadian Pediatric Demyelinating Disease Network providing a stool sample were eligible. Twenty patients with MS (McDonald criteria) with symptom onset <18 years were matched to 20 controls by sex, age (±3 years), stool consistency, and race. Microbial taxonomy and functional potentials were estimated from stool sample-derived metagenomic reads and compared by disease status (MS vs controls) and disease-modifying drug (DMD) exposure using alpha diversity, relative abundance, and prevalence using Wilcoxon rank sum, ALDEx2, and Fisher exact tests, respectively. RESULTS: Individuals with MS were aged 13.6 years (mean) at symptom onset and 8 were DMD-naive. Mean ages at stool sample were 16.1 and 15.4 years for MS and control participants, respectively; 80% were girls. Alpha diversity of enzymes and proteins did not differ by disease or DMD status (p > 0.20), but metabolic pathways, gene annotations, and microbial taxonomy did. Individuals with MS (vs controls) exhibited higher methanogenesis prevalence (odds ratio 10, p = 0.044) and Methanobrevibacter abundance (log2 fold change [LFC] 1.7, p = 0.0014), but lower homolactic fermentation abundance (LFC -0.48, p = 0.039). Differences by DMD status included lower phosphate butyryl transferase for DMD-naive vs exposed patients with MS (LFC -1.0, p = 0.033). DISCUSSION: The gut microbiome's functional potential and taxonomy differed between individuals with pediatric-onset MS vs controls, including higher prevalence of a methane-producing pathway from Archaea and depletion of the lactate fermentation pathway. DMD exposure was associated with butyrate-producing enzyme enrichment. Together these findings indicate that the gut microbiome of individuals with MS may have a disturbed functional potential.

Microbiome-Mediated Immune Signaling in Inflammatory Bowel Disease and Colorectal Cancer: Support From Meta-omics Data.

Chronic intestinal inflammation and microbial dysbiosis are hallmarks of colorectal cancer (CRC) and inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis. However, the mechanistic relationship between gut dysbiosis and disease has not yet been fully characterized. Although the "trigger" of intestinal inflammation remains unknown, a wealth of evidence supports the role of the gut microbiome as a mutualistic pseudo-organ that significantly influences intestinal homeostasis and is capable of regulating host immunity. In recent years, culture-independent methods for assessing microbial communities as a whole (termed meta-omics) have grown beyond taxonomic identification and genome characterization (metagenomics) into new fields of research that collectively expand our knowledge of microbiomes. Metatranscriptomics, metaproteomics, and metabolomics are meta-omics techniques that aim to describe and quantify the functional activity of the gut microbiome. Uncovering microbial metabolic contributions in the context of IBD and CRC using these approaches provides insight into how the metabolic microenvironment of the GI tract shapes microbial community structure and how the microbiome, in turn, influences the surrounding ecosystem. Immunological studies in germ-free and wild-type mice have described several host-microbiome interactions that may play a role in autoinflammation. Chronic colitis is a precursor to CRC, and changes in the gut microbiome may be an important link triggering the neoplastic process in chronic colitis. In this review, we describe several microbiome-mediated mechanisms of host immune signaling, such as short-chain fatty acid (SCFA) and bile acid metabolism, inflammasome activation, and cytokine regulation in the context of IBD and CRC, and discuss the supporting role for these mechanisms by meta-omics data.

The gut microbiota in pediatric multiple sclerosis and demyelinating syndromes.

OBJECTIVE: To examine the gut microbiota in individuals with and without pediatric-onset multiple sclerosis (MS). METHODS: We compared stool-derived microbiota of Canadian Pediatric Demyelinating Disease Network study participants ≤21 years old, with MS (disease-modifying drug [DMD] exposed and naïve) or monophasic acquired demyelinating syndrome [monoADS] (symptom onset <18 years), and unaffected controls. All were ≥30 days without antibiotics or corticosteroids. V4 region 16S RNA gene-derived amplicon sequence variants (Illumina MiSeq) were assessed using negative binomial regression and network analyses; rate ratios were age- and sex-adjusted (aRR). RESULTS: Thirty-two MS, 41 monoADS (symptom onset [mean] = 14.0 and 6.9 years) and 36 control participants were included; 75%/56%/58% were female, with mean ages at stool sample = 16.5/13.8/15.1 years, respectively. Nine MS cases (28%) were DMD-naïve. Although microbiota diversity (alpha, beta) did not differ between participants (p > 0.1), taxa-level and gut community networks did. MS (vs. monoADS) exhibited > fourfold higher relative abundance of the superphylum Patescibacteria (aRR = 4.2;95%CI:1.6-11.2, p = 0.004, Q = 0.01), and lower abundances of short-chain fatty acid (SCFA)-producing Lachnospiraceae (Anaerosporobacter) and Ruminococcaceae (p, Q < 0.05). DMD-naïve MS cases were depleted for Clostridiales vadin-BB60 (unnamed species) versus either DMD-exposed, controls (p, Q < 0.01), or monoADS (p = 0.001, Q = 0.06) and exhibited altered community connectedness (p < 10-9 Kruskal-Wallis), with SCFA-producing taxa underrepresented. Consistent taxa-level findings from an independent US Network of Pediatric MS Centers case/control (n = 51/42) cohort included >eightfold higher abundance for Candidatus Stoquefichus and Tyzzerella (aRR = 8.8-12.8, p < 0.05) in MS cases and 72%-80% lower abundance of SCFA-producing Ruminococcaceae-NK4A214 (aRR = 0.38-0.2, p ≤ 0.01). INTERPRETATION: Gut microbiota community structure, function and connectivity, and not just individual taxa, are of likely importance in MS.

Evaluation of the clinical value of routine radiographic examination during convalescence for tibial plateau-leveling osteotomy.

OBJECTIVE: To determine how frequently routine follow-up radiographic findings would result in a change to the postoperative plan following tibial plateau-leveling osteotomy (TPLO) in dogs. STUDY DESIGN: Retrospective study SAMPLE POPULATION: Short-term group: 100 cases; intermediate-term group: 50 cases. METHODS: Medical records of 100 consecutive cases meeting the inclusion criteria were reviewed (the short-term group). The cases had no owner-perceived issues and underwent routinely prescribed radiographic follow up between 40 and 60 postoperative days after TPLO performed by one experienced surgeon. Complications identified on physical examination (PE) and radiographic examination (RE) were recorded, along with any changes to the postoperative plan. Medical records of 50 consecutive cases that had short-term and intermediate-term (≥180 days) REs and PEs were reviewed similarly (intermediate-term group). RESULTS: Fifty-one cases in the short-term group had no complications on PE or RE. Forty-nine dogs were diagnosed with minor complications (patellar ligament desmitis, patella or fibula fracture, gait abnormalities): 42 on RE only; 6 on PE and RE; 1 on PE only. Exercise restriction was extended for 2 weeks in 2 cases with radiographic patellar ligament desmitis. Two cases in the intermediate-term group had minor complications at intermediate-term RE. No new PE or RE complications developed between short-term and intermediate-term evaluations. CONCLUSION: At routine rechecks of dogs with no owner-perceived issues after TPLO, 49% had minor complications but only 2% were deemed significant enough to alter patient management. The likelihood of new radiographic complications developing after short-term evaluation is low. CLINICAL SIGNIFICANCE: Routine radiographic recheck examinations rarely altered the postoperative plan in TPLO cases with unremarkable clinical recoveries.

Practical guidance for clinical laboratories for SARS-CoV-2 serology testing.

The landscape of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic testing is rapidly evolving. While serology testing has limited diagnostic capacity for acute infection, its role in providing population-based information on positivity rates and informing evidence-based decision making for public health recommendations is increasing. With the global availability of vaccines, there is increasing pressure on clinical laboratories to provide antibody screening and result interpretation for vaccinated and non-vaccinated individuals. Here we present the most up-to-date data on SARS-CoV-2 antibody timelines, including the longevity of antibodies, and the production and detection of neutralizing antibodies. Additionally, we provide practical guidance for clinical microbiology laboratories to both verify commercial serology assays and choose appropriate testing algorithms for their local populations.

Impact of the Chin-Down Posture on Temporal Measures of Patients With Dysphagia: A Pilot Study.

Purpose The chin-down position is a commonly prescribed posture by health care professionals to alleviate the symptoms of dysphagia. Yet, how the technique influences swallowing physiology lacks clarity. Our goal was to examine the impact of the postural technique on patients with various medical conditions and swallowing impairments. Method Temporal and functional measures were examined with videofluoroscopy in the chin-down and neutral head position on 15 patients. Also, timing differences between head positions were examined to determine the presence of improvement during the chin-down posture. Results The primary finding was chin-down posture swallows prolonged the elapsed time between when the prematurely spilled bolus entered the pharynx relative to swallow onset compared to the neutral head position (p = .006). Also, no improvement in airway protection was found when performing the postural technique. Conclusions The chin-down posture may benefit patients with specific swallowing impairments. However, the general use of the technique for all patients who experience swallowing difficulty might be negligent and could potentially have adverse or no effect on patient outcomes. Future studies examining patients with the same pathophysiology are needed to understand the benefit of the chin-down posture based on swallowing impairment.