Dairying, diseases and the evolution of lactase persistence in Europe.

In European and many African, Middle Eastern and southern Asian populations, lactase persistence (LP) is the most strongly selected monogenic trait to have evolved over the past 10,000 years1. Although the selection of LP and the consumption of prehistoric milk must be linked, considerable uncertainty remains concerning their spatiotemporal configuration and specific interactions2,3. Here we provide detailed distributions of milk exploitation across Europe over the past 9,000 years using around 7,000 pottery fat residues from more than 550 archaeological sites. European milk use was widespread from the Neolithic period onwards but varied spatially and temporally in intensity. Notably, LP selection varying with levels of prehistoric milk exploitation is no better at explaining LP allele frequency trajectories than uniform selection since the Neolithic period. In the UK Biobank4,5 cohort of 500,000 contemporary Europeans, LP genotype was only weakly associated with milk consumption and did not show consistent associations with improved fitness or health indicators. This suggests that other reasons for the beneficial effects of LP should be considered for its rapid frequency increase. We propose that lactase non-persistent individuals consumed milk when it became available but, under conditions of famine and/or increased pathogen exposure, this was disadvantageous, driving LP selection in prehistoric Europe. Comparison of model likelihoods indicates that population fluctuations, settlement density and wild animal exploitation-proxies for these drivers-provide better explanations of LP selection than the extent of milk exploitation. These findings offer new perspectives on prehistoric milk exploitation and LP evolution.

Clinical Outcomes of a Newly Instituted Hospital at Home Program During the COVID19 Pandemic.

Context: The COVID19 pandemic stressed U.S. health systems beyond their capacity and created worsening clinical outcomes. Hospital a Home (HaH) programs were utilized infrequently prior to pandemic. The Acute Care at Home Waiver was introduced in 2020 to facilitate the creation of HaH programs with a goal of promoting treatment in the home setting. A potential alternative approach to creating rapid inpatient level health system capacity is providing hospital-level care at home to substitute for inpatient hospitalization. The overall impact on clinical outcomes of a HaH program in patients with COVID19 is not well understood. Objective: To compare clinical outcomes of a HaH program versus usual hospital care for patients admitted for COVID19. Study Design: Matched case-control retrospective chart review. Setting or Dataset: Academic medical center. Population studied: Patients admitted with COVID19 and subsequently enrolled into the HaH program from February 1, 2021 to January 31, 2022. Patients aged <18 were excluded from consideration for enrollment. A case-control sample was matched on age, gender, and severity of illness. A total of 200 patients (100 HaH and 100 control) were included for analysis. Outcome Measures: Primary outcome: 30-day readmissions, Secondary outcomes: Inpatient length of stay (iLOS) defined as length of stay in the physical hospital, total length of stay (tLOS) (sum of iLOS and HaH program days), time to readmission, and 30-day emergency department visits. Results: Analysis included 200 patents. The mean age was 50.4. The sample was 55% female. 48.5% were black, 43.5% were white, and 8% were other races. Compared with usual care patients, HaH patients had no difference in 30-day readmissions (11% vs. 14%, p=0.648), mean days to readmission (9.0 vs. 11.8, p=0.201), or return ED visits (17% vs. 20%, p=0.701). Inpatient LOS (5.7 vs. 9.4 days, p=0.005) was shorter in the HaH group. Total LOS (13.0 vs. 9.4 days, p<0. 001) was longer in the HaH group. Conclusions: The HaH program was associated with no difference in readmissions, time to readmission, or return ED visits compared to usual hospital care. HaH programs were associated with shorter inpatient length of stays, but longer total length of stays. In surge times, HaH programs could potentially reduce iLOS and increase bed capacity. Future studies should look to evaluate the economic impact of HaH programs and investigate the drivers of the increased tLOS.

Implementation of a Telemedicine Student Clinical Experience.

Background: As part of a curricular change, an academic medical center implemented a medical student telemedicine clinical experience for first-year medical students in October 2020. This research is a process evaluation of the implementation of a preclerkship medical student telemedicine clinical experience. Methods: Patients with two or more chronic diseases were recruited from affiliated primary care practices. We monitored the recruitment and retainment of patients throughout the curriculum. We used surveys to evaluate patient, student, and primary care overall experience with the program. We tracked referrals to higher levels of care and assessed skills students' felt they practice with each encounter. We followed progression of notes through chart review as the year progressed. Results: Of the 408 patients contacted, 150 agreed to participate in this program (36%). Of 1,053 scheduled visits, 686 (65%) were successfully completed. Seventy-five percent of patients were seen two or more times. Nearly 70% of surveyed patients felt that the clinical experience enhanced their communication with their primary care provider, and nearly 90% stated that students were "somewhat" or "extremely" professional. The majority (97%) of students reported an "excellent" or "good" view of the medical student telemedicine clinical experience. Qualitative measures of student performance, such as note writing, showed improvement over the course of the curriculum. Conclusions: Our data suggest that patients, students, and primary care providers were widely accepting of the curriculum, patients were successfully recruited and retained, and students successfully practiced key clinical skills on a telemedicine platform.

Dual endothelin receptor antagonism increases resting energy expenditure in people with increased adiposity.

Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals. Using a double blind, placebo-controlled, crossover design, 32 participants [healthy weight (HW): n = 16, BMI: 21.3 ± 2.8 kg/m2, age: 26 ± 7 yr and overweight/obese (OB): n = 16, BMI: 33.5 ± 9.5 kg/m2, age: 31 ± 6 yr] were randomized to receive either 125 mg of bosentan (ETA/B antagonism) or placebo twice per day for 3 days. Breath-by-breath gas exchange data were collected and REE was assessed by indirect calorimetry. Venous blood samples were analyzed for concentrations of endothelin-1 (ET-1). Treatment with bosentan increased plasma ET-1 in both OB and HW groups. Within the OB group, the changes in absolute REE (PLA: -77.6 ± 127.6 vs. BOS: 72.2 ± 146.6 kcal/day; P = 0.046). The change in REE was not different following either treatment in the HW group. Overall, absolute plasma concentrations of ET-1 following treatment with bosentan were significantly associated with kcal/day of fat (r = 0.488, P = 0.005), percentage of fat utilization (r = 0.415, P = 0.020), and inversely associated with the percentage of carbohydrates (r = -0.419, P = 0.019), and respiratory exchange ratio (r = -0.407, P = 0.023). Taken together, these results suggest that modulation of the endothelin system may represent a novel therapeutic approach to increase both resting metabolism and caloric expenditure, and reduce CVD risk in people with increased adiposity.NEW & NOTEWORTHY Findings from our current translational investigation demonstrate that dual endothelin A/B receptor antagonism increases total REE in overweight/obese individuals. These results suggest that modulation of the endothelin system may represent a novel therapeutic target to increase both resting metabolism and caloric expenditure, enhance weight loss, and reduce CVD risk in seemingly healthy individuals with elevated adiposity.

A robust mean and variance test with application to high-dimensional phenotypes.

Most studies of continuous health-related outcomes examine differences in mean levels (location) of the outcome by exposure. However, identifying effects on the variability (scale) of an outcome, and combining tests of mean and variability (location-and-scale), could provide additional insights into biological mechanisms. A joint test could improve power for studies of high-dimensional phenotypes, such as epigenome-wide association studies of DNA methylation at CpG sites. One possible cause of heterogeneity of variance is a variable interacting with exposure in its effect on outcome, so a joint test of mean and variability could help in the identification of effect modifiers. Here, we review a scale test, based on the Brown-Forsythe test, for analysing variability of a continuous outcome with respect to both categorical and continuous exposures, and develop a novel joint location-and-scale score (JLSsc) test. These tests were compared to alternatives in simulations and used to test associations of mean and variability of DNA methylation with gender and gestational age using data from the Accessible Resource for Integrated Epigenomics Studies (ARIES). In simulations, the Brown-Forsythe and JLSsc tests retained correct type I error rates when the outcome was not normally distributed in contrast to the other approaches tested which all had inflated type I error rates. These tests also identified > 7500 CpG sites for which either mean or variability in cord blood methylation differed according to gender or gestational age. The Brown-Forsythe test and JLSsc are robust tests that can be used to detect associations not solely driven by a mean effect.

Structural core of the executive control network: A high angular resolution diffusion MRI study.

Executive function (EF) is a set of cognitive capabilities considered essential for successful daily living, and is negatively affected by ageing and neurodegenerative conditions. Underpinning EF performance are functional nodes in the executive control network (ECN), while the structural connectivity underlying this network is not well understood. In this paper, we evaluated the structural white matter tracts that interconnect the ECN and investigated their relationship to the EF performance. Using high-angular resolution diffusion MRI data, we performed tractography analysis of structural connectivity in a cognitively normal cohort (n = 140), specifically targeting the connectivity between ECN nodes. Our data revealed the presence of a strongly-connected "structural core" of the ECN comprising three components: interhemispheric frontal connections, a fronto-parietal subnetwork and fronto-striatal connections between right dorsolateral prefrontal cortex and right caudate. These pathways were strongly correlated with EF performance (p = .003). Post-hoc analysis of subregions within the significant ECN connections showed that these effects were driven by a highly specific subset of interconnected cortical regions. The structural core subnetwork of the functional ECN may be an important feature crucial to a better future understanding of human cognition and behaviour.

Blood RNA analysis can increase clinical diagnostic rate and resolve variants of uncertain significance.

PURPOSE: Diagnosis of genetic disorders is hampered by large numbers of variants of uncertain significance (VUSs) identified through next-generation sequencing. Many such variants may disrupt normal RNA splicing. We examined effects on splicing of a large cohort of clinically identified variants and compared performance of bioinformatic splicing prediction tools commonly used in diagnostic laboratories. METHODS: Two hundred fifty-seven variants (coding and noncoding) were referred for analysis across three laboratories. Blood RNA samples underwent targeted reverse transcription polymerase chain reaction (RT-PCR) analysis with Sanger sequencing of PCR products and agarose gel electrophoresis. Seventeen samples also underwent transcriptome-wide RNA sequencing with targeted splicing analysis based on Sashimi plot visualization. Bioinformatic splicing predictions were obtained using Alamut, HSF 3.1, and SpliceAI software. RESULTS: Eighty-five variants (33%) were associated with abnormal splicing. The most frequent abnormality was upstream exon skipping (39/85 variants), which was most often associated with splice donor region variants. SpliceAI had greatest accuracy in predicting splicing abnormalities (0.91) and outperformed other tools in sensitivity and specificity. CONCLUSION: Splicing analysis of blood RNA identifies diagnostically important splicing abnormalities and clarifies functional effects of a significant proportion of VUSs. Bioinformatic predictions are improving but still make significant errors. RNA analysis should therefore be routinely considered in genetic disease diagnostics.

Correction: Blood RNA analysis can increase clinical diagnostic rate and resolve variants of uncertain significance.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Outcomes of an Emergency Department Observation Unit-Based Pathway for the Treatment of Uncomplicated Vaso-occlusive Events in Sickle Cell Disease.

STUDY OBJECTIVE: This was a prospective, pre-post, 13-year observational study documenting the multiyear implementation of an observation unit sickle cell pathway for patients with uncomplicated vaso-occlusive events. METHODS: The sickle cell pathway begins with rapid triage to identify patients with uncomplicated vaso-occlusive events for immediate transfer to the observation unit and initiation of patient-controlled analgesia followed by repeated evaluations of pain and identification of other complications. Data were abstracted from the electronic medical record or observation unit database. The sickle cell pathway was initiated in April 2006. Major revisions of it were carried out in June 2009 (physician evaluation occurs in sickle cell pathway and only patient-controlled analgesia administration of medications) and October 2010 (multidisciplinary management and individual dosing). RESULTS: Annual ED visits ranged between 287 and 528. The preimplementation hospital admission rate was 33% (123/368), 3-day return rate 16% (60/368), and 30-day return rate 67% (248/368). Refinements to the sickle cell pathway have resulted in a decrease in admission rate to 20% (258/1276); 3-day return rate, to 3.6% (46/1,276); and 30-day return rate, to 41% (525/1,276) for the past 3 years. CONCLUSION: The use of a sickle cell pathway for the treatment of uncomplicated vaso-occlusive events has been effective in providing rapid treatment and reducing hospital admissions. However, it was not only the intervention and its refinement that made the sickle cell pathway successful. With the Consolidated Framework for Implementation Research, it was discerned that outer setting factors of organizational commitment to the care of patients with SCD, inner setting factors of learning climate and leadership engagement, individuals, and process contributed to the success of the sickle cell pathway.

A Potential Pitfall of Using Focused Assessment With Sonography for Trauma in Pediatric Trauma.

Prospective studies have shown sensitivities of 73% to 88% and specificities of 98% to 100% for using the focused assessment with sonography for trauma (FAST) examination to identify free fluid in adult trauma patients. However, the efficacy of FAST examinations for pediatric trauma patients has not been well defined, and studies looking at diagnostic performance have had varied results. We describe 3 cases of the potential pitfalls of the pediatric FAST examination in pediatric trauma patients using an advanced-processing ultrasound machine. We hypothesize several etiologies for these false-positive findings in the setting of advanced image-processing capabilities of point-of-care ultrasound. We also discuss the reevaluation of clinical algorithms and interpretation practices when using the FAST examination in pediatric trauma.

Rapid Assessment of the Neonate With Sonography (RANS) Scan.

The use of point-of-care sonography in clinical settings such as emergency medicine and intensive care units has increased, but adoption in neonatology has been slow. Unlike the focused assessment with sonography for trauma scan used in adults, a quick bedside scan to rapidly evaluate an acutely deteriorating neonate does not exist. The objective of our article is to introduce a focused bedside ultrasound scan that is easy to learn, rapidly performed, and relatively inexpensive.© 2018 by the American Institute of Ultrasound in Medicine.

'Tramline Rescue': A salvage technique for the failed elliptical excision on the leg.

We outline an approach to achieve wound closure in the event of a failed elliptical excision on the leg. The various steps are shown, and a clinical example is presented.

The McConnell Sign is Seen in Patients With Acute Chest Syndrome.

Bedside ultrasound is often used as a part of the evaluation of patients who are critically ill. The McConnell sign is an important echocardiographic finding in some critically ill patients with pulmonary embolism and an acute right ventricular infarct. We present 3 critically ill patients with confirmed acute chest syndrome who showed the McConnell sign on echocardiography. In patients with sickle cell disease presenting with chest pain and shortness of breath, the presence of the McConnell sign does not narrow the differential diagnosis between pulmonary embolism, an acute right ventricular infarct, and acute chest syndrome.

Collagen (COL4A) mutations are the most frequent mutations underlying adult focal segmental glomerulosclerosis.

BACKGROUND: Multiple genes underlying focal segmental glomerulosclerosis (FSGS) and/or steroid-resistant nephrotic syndrome (SRNS) have been identified, with the recent inclusion of collagen IV mutations responsible for Alport disease (AD) or thin basement membrane nephropathy (TBMN). We aimed to investigate the distribution of gene mutations in adult patients with primary FSGS/SRNS by targeted next generation sequencing (NGS). METHODS: Eighty-one adults from 76 families were recruited; 24 families had a history of renal disease. A targeted NGS panel was designed and applied, covering 39 genes implicated in FSGS/SRNS including COL4A3-5. RESULTS: Confirmed pathogenic mutations were found in 10 patients (6 with family history) from 9 families (diagnostic rate 12%). Probably pathogenic mutations were identified in an additional six patients (combined diagnostic rate 20%). Definitely pathogenic mutations were identified in 22% of patients with family history and 10% without. Mutations in COL4A3-5 were present in eight patients from six families, representing 56% of definitely pathogenic mutations, and establishing a diagnosis of AD in six patients and TBMN in two patients. Collagen mutations were identified in 38% of families with familial FSGS, and 3% with sporadic FSGS, with over half the mutations occurring in COL4A5. Patients with collagen mutations were younger at presentation and more likely to have family history, haematuria and glomerular basement membrane abnormalities. CONCLUSIONS: We show that collagen IV mutations, including COL4A5, frequently underlie FSGS and should be considered, particularly with a positive family history. Targeted NGS improves diagnostic efficiency by investigating many candidate genes in parallel.

Pulmonary platelet thrombi and vascular pathology in acute chest syndrome in patients with sickle cell disease.

A growing body of evidence suggests a role for platelets in sickle cell disease (SCD). Despite the proinflammatory, occlusive nature of platelets, a role for platelets in acute chest syndrome (ACS), however, remains understudied. To provide evidence and potentially describe contributory factors for a putative link between ACS and platelets, we performed an autopsy study of 20 SCD cases-10 of whom died from ACS and 10 whose deaths were not ACS-related. Pulmonary histopathology and case history were collected. We discovered that disseminated pulmonary platelet thrombi were present in 3 out of 10 of cases with ACS, but none of the matched cases without ACS. Those cases with detected thrombi were associated with significant deposition of endothelial vWF and detection of large vWF aggregates adhered to endothelium. Potential clinical risk factors were younger age and higher platelet count at presentation. However, we also noted a sharp and significant decline in platelet count prior to death in each case with platelet thrombi in the lungs. In this study, neither hydroxyurea use nor perimortem transfusion was associated with platelet thrombi. Surprisingly, in all cases, there was profound pulmonary artery remodeling with both thrombotic and proliferative pulmonary plexiform lesions. The severity of remodeling was not associated with a severe history of ACS, or hydroxyurea use, but was inversely correlated with age. We thus provide evidence of undocumented presence of platelet thrombi in cases of fatal ACS and describe clinical correlates. We also provide novel correlates of pulmonary remodeling in SCD.

Barriers to outpatient stress testing follow-up for low-risk chest pain patients presenting to an ED chest pain unit.

INTRODUCTION: Outpatient stress testing (OST) after evaluation in the emergency department (ED) is an acceptable evaluation method for patients presenting to the ED with low-risk chest pain (CP). However, not all patients return for OST. Barriers to follow-up evaluation exist and are poorly understood. In this study, we examined the influence of demographic and social characteristics on OST compliance. METHODS: Data were collected on low-risk CP patients with scheduled OSTs. OST compliance was assessed and then analyzed for correlation with potential barriers including insurance type; age; sex; race; employment status; the distance the patient lived from the hospital; whether or not the patient had a primary care physician; whether or not the patient had a history of hypertension or diabetes; and whether or not the patient had a history of tobacco, alcohol, or illicit drug use. RESULTS: A total of 275 patients were enrolled over a 5-month period. These patients had an OST follow-up rate of 61.82% within 72hours of discharge from the ED. Patients with Medicaid were statistically less likely (odds ratio [OR], 0.439) to complete OST. Patients with commercial insurance (OR, 1.8225), who were employed (OR, 2.299), or who were retired (OR, 3.44) were more likely to complete OST. All of the other variables analyzed were not statistically significant factors in OST compliance. CONCLUSION: More than one-third of low-risk CP patients do not follow-up with scheduled OST. Of the variables analyzed, both employment status and insurance type were statistically significant and should be included in risk stratification strategies for OST.

Use of biliary stent in laparoscopic common bile duct exploration.

INTRODUCTION: It is well supported in the literature that laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis has equal efficacy when compared to ERCP followed by laparoscopic cholecystectomy. Decompression after supra-duodenal choledochotomy is common practice as it reduced the risk of bile leaks. We conducted a prospective non-randomized study to compare outcomes and length of stay in patients undergoing biliary stent insertion versus T-tube drainage following LCBDE via choledochotomy. METHODS AND PROCEDURES: The study involved 116 patients with choledocholithiasis who underwent LCBDE and decompression of the biliary system by either ante-grade biliary stent or T-tube insertion. A 7 French straight/duodenal curve biliary Diagmed™ stent (9-11 cm) was placed in 82 patients (Biliary Stent Group). T-tube insertion was used for 34 patients (T-tube group). The length of hospital stay and complications for the selected patients were recorded. All trans-cystic common bile duct explorations were excluded from the study. RESULTS: The mean hospital stay for patients who underwent ante-grade biliary stent or T-tube insertion after LBCDE were 1 and 3.4 days, respectively. This is a statistically significant result with a p value of less than 0.001. Of the T-tube group, two patients required laparoscopic washout due to bile leaks, one had ongoing biliary stasis and one reported ongoing pain whilst the T-tube was in situ. A complication rate of 11.2%, this was a significant finding. There were no complications or concerns reported for the Biliary Stent Group. CONCLUSION: Our results show that there is a significant reduction in length of hospital stay and morbidity for patients that have ante-grade biliary stent decompression of the CBD post laparoscopic choledochotomy when compared T-tube drainage. This implies that ante-grade biliary stent insertion is likely to reduce costs and increase overall patient satisfaction. We support the use of ante-grade biliary stent insertion during LCBDE when primary closure is not preferred.

Use of a Novel Abdominal Aortic and Junctional Tourniquet to Reduce or Eliminate Flow in the Brachial and Popliteal Arteries in Human Subjects.

BACKGROUND: Penetrating injuries of the proximal large arteries are a common cause of death on the battlefield due to rapid exsanguination. Applying an effective tourniquet to stop bleeding at the axillary and proximal femoral arteries (junctional sites) is difficult. Prior studies have shown that the Abdominal Aortic and Junctional Tourniquet (AAJT) effectively reduced blood flow in the common femoral artery with application of the device around the lower abdomen. Our objective was to determine the effectiveness of the AAJT to stop blood flow in the proximal femoral artery (PFA), and the axillary artery (AA). METHOD: This was a prospective observational trial using human volunteers. The AAJT consists of a wedge-shaped bladder and integrated strap. The bladder has an integrated manometer, which is used to measure the pressure in the bladder. For the AA, the AAJT was placed over the axillary junction at the anterior axillary line with the strap placed across the contralateral shoulder. For the PFA, the AAJT bladder was placed over the right groin with the strap positioned across both femoral trochanters. Spectral Doppler measurements were taken of the PFA and AA at baseline and as the bladder was inflated. Collected data included pressure of the AAJT.