A genetic mouse model mimicking MET related human osteofibrous dysplasia is characterized by delays in fracture repair and defective osteogenesis.

Osteofibrous dysplasia (OFD) is a rare, benign, fibro-osseous lesion that occurs most commonly in the tibia of children. Tibial involvement leads to bowing and predisposes to the development of a fracture which exhibit significantly delayed healing processes, leading to prolonged morbidity. We previously identified gain-of-function mutations in the MET gene as a cause for OFD. In our present study, we test the hypothesis that gain-of-function MET mutations impair bone repair due to reduced osteoblast differentiation. A heterozygous Met exon 15 skipping (MetΔ15-HET) mouse was created to imitate the human OFD mutation. The mutation results in aberrant and dysregulation of MET-related signaling determined by RNA-seq in the murine osteoblasts extracted from the wide-type and genetic mice. Although no gross skeletal defects were identified in the mice, fracture repair was delayed in MetΔ15-HET mice, with decreased bone formation observed 2-week postfracture. Our data are consistent with a novel role for MET-mediated signaling regulating osteogenesis.

The pluripotency factor Nanog regulates pericentromeric heterochromatin organization in mouse embryonic stem cells.

An open and decondensed chromatin organization is a defining property of pluripotency. Several epigenetic regulators have been implicated in maintaining an open chromatin organization, but how these processes are connected to the pluripotency network is unknown. Here, we identified a new role for the transcription factor NANOG as a key regulator connecting the pluripotency network with constitutive heterochromatin organization in mouse embryonic stem cells. Deletion of Nanog leads to chromatin compaction and the remodeling of heterochromatin domains. Forced expression of NANOG in epiblast stem cells is sufficient to decompact chromatin. NANOG associates with satellite repeats within heterochromatin domains, contributing to an architecture characterized by highly dispersed chromatin fibers, low levels of H3K9me3, and high major satellite transcription, and the strong transactivation domain of NANOG is required for this organization. The heterochromatin-associated protein SALL1 is a direct cofactor for NANOG, and loss of Sall1 recapitulates the Nanog-null phenotype, but the loss of Sall1 can be circumvented through direct recruitment of the NANOG transactivation domain to major satellites. These results establish a direct connection between the pluripotency network and chromatin organization and emphasize that maintaining an open heterochromatin architecture is a highly regulated process in embryonic stem cells.

Independence of repressive histone marks and chromatin compaction during senescent heterochromatic layer formation.

The expansion of repressive epigenetic marks has been implicated in heterochromatin formation during embryonic development, but the general applicability of this mechanism is unclear. Here we show that nuclear rearrangement of repressive histone marks H3K9me3 and H3K27me3 into nonoverlapping structural layers characterizes senescence-associated heterochromatic foci (SAHF) formation in human fibroblasts. However, the global landscape of these repressive marks remains unchanged upon SAHF formation, suggesting that in somatic cells, heterochromatin can be formed through the spatial repositioning of pre-existing repressively marked histones. This model is reinforced by the correlation of presenescent replication timing with both the subsequent layered structure of SAHFs and the global landscape of the repressive marks, allowing us to integrate microscopic and genomic information. Furthermore, modulation of SAHF structure does not affect the occupancy of these repressive marks, nor vice versa. These experiments reveal that high-order heterochromatin formation and epigenetic remodeling of the genome can be discrete events.

Open and closed domains in the mouse genome are configured as 10-nm chromatin fibres.

The mammalian genome is compacted to fit within the confines of the cell nucleus. DNA is wrapped around nucleosomes, forming the classic "beads-on-a-string" 10-nm chromatin fibre. Ten-nanometre chromatin fibres are thought to condense into 30-nm fibres. This structural reorganization is widely assumed to correspond to transitions between active and repressed chromatin, thereby representing a chief regulatory event. Here, by combining electron spectroscopic imaging with tomography, three-dimensional images are generated, revealing that both open and closed chromatin domains in mouse somatic cells comprise 10-nm fibres. These findings indicate that the 30-nm chromatin model does not reflect the true regulatory structure in vivo.

How people learn: insights for medical faculty.

To increase medical students' and residents' understanding and retention, faculty need to teach from a knowledge standpoint and understanding of how individuals learn. We know from cognitive information processing that learners remember only a small portion of what they read or hear but remember up to 90% of information when strong active learning modalities are included. Faculty also need to be aware of different learning styles-kinesthetic, visual, and auditory-and ensure that they are including methods that can reach all learners. The cognitive and information processing theories of learning provide insights to educators related to building on prior knowledge from learning and limiting the number of points taught so learners can process and retain the information. Strategies such as a flipped classroom model and question clicker technology can assist in reaching learning goals. Fundamental conditions for learning include awareness, interest, motivation, relevance, engagement, reinforcement, and support.

General Practitioners' Experience of Remote Consultations by Telephone in the General Practice Setting during the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID 19) pandemic brought substantial changes in the way doctors used to interact with patients. In the general practice, consultation over the phone has become a norm now. However, it is not well known how this new mode of consultation affected clinicians' practices. Objective of this study was to find out if doctors working in the general practices were trained enough for telephonic consultation and how this new mode of consultation affected their clinical practice in general. It was an online survey. Information was gathered by using an online questionnaire which was sent electronically to general practitioners (GPs) and general practitioner speciality trainees (GPSTs) working in the general practices based in Leicestershire. Data were analyzed by using software SPSS. Descriptive characteristics of participants were reported in terms of numbers and percentages, whereas Chi square test was run to assess if there is a difference between GPs and GPSTs in terms of their experience of remote consultations by telephone. The questionnaire response rate was 69.3% (n = 133/192). Of the total, 54.1% (n = 72/133) of participants were women. About 36% (n = 48/133) of the participants were GPSTs, whereas 64% (n = 85/133) were qualified GPs. Not having enough training for phone consultation, technical issues during consultation, inadequate supervision framework, difficulties in building therapeutic alliance with patients, making diagnosis and risk assessment, and increased duration of consultation were identified as issues. Similarly, concerns around patients' confidentiality and medico legal issues were highlighted. GPs and GPSTs reported similar difficulties. In conclusion, lack of training for the telephonic consultation has been identified as a unanimous issue along with other challenges to phone consultations. There is an urgent need to take measures to make telephone consultation more successful, enjoyable, and safe for patient care by addressing identified issues. Larger studies with representative samples are needed to increase generalizability of our findings.

Prosthesis for Unilateral Isolated Proximal Focal Femoral Deficiency: A Case Report and Review of the Literature.

A 14-month-old female child was brought to us by her parents with the complaint of progressive shortening of her right lower limb since birth. Born to non-consanguineous parents from a poor socioeconomic background, her birth and antenatal history were uneventful. Physical examination revealed no facial dysmorphism; however, her right thigh was short and bulky, and there were restrictions in hip, knee, and ankle movements. The pediatric evaluation showed normal growth and development. X-rays confirmed proximal femoral focal deficiency (PFFD) of the right lower limb. After extensive parental counseling regarding the condition, potential interventions, and outcomes, the parents opted for prosthetic management due to concerns about surgical costs, risks, and cosmetic outcomes. A custom-made extension prosthesis was prepared for the limb and was fit. At a follow-up of one year, the child exhibited a normal gait pattern with stable hip, knee, and ankle motion, and the parents expressed satisfaction with the prosthetic management, preferring it over surgical intervention for the time being.

Comparison of hospitalist service staffing models at Baylor University Medical Center.

Background: Baylor University Medical Center benefits from being a quaternary care center with 900+ licensed beds and multiple different models to staff patients on the hospitalist service. These models include hospitalist only, resident teaching teams, and two different advanced practice practitioner teams. The primary goal of this study was to assess these different staffing models and to ascertain which model, if any, has better outcomes related to length of stay, total hospital charges, 30-day readmission rates, patient satisfaction, hospital-acquired infections, mortality, and early discharges. Methods: The study was an observational retrospective chart review of all discharges from the hospitalist service at Baylor University Medical Center from October 1, 2021, to February 28, 2022. Patients were included if the hospitalist team was the primary team of record at the time of discharge. A total of 7803 patients were included. Results: There was no difference in patient satisfaction, hospital-acquired infections, and mortality between the groups. The teaching teams had a shorter length of stay before the removal of outliers. Independent advanced practice practitioners reliably had more patients discharged before 11:30 am. Results support the concept of continuity of care, as well as lower patient-to-provider ratios. Conclusions: These results have actionable implications that support the use of different advanced practice practitioner teams for the safe care of hospitalized patients as well as the safe integration of residents into patient care.

COVID-19's impact on family medicine resident training and wellness.

Background: The COVID-19 global pandemic has raised many challenges in training family medicine residents. Family medicine is at the frontline for treating and managing patients with COVID-19. Attention is needed on the critical issue of the effect of the pandemic on resident training, the safety of those performing needed medical services, and the psychological well-being of trainees. Methods: We performed a cross-sectional, 25-question survey-based study to evaluate the perceived effect of the COVID-19 pandemic on family medicine residents' training and residents' well-being in the state of Texas. Results: A total of 250 Texas-based family medicine residents were surveyed with a response rate of 12.8% (n = 32). After the pandemic began, all residents worried about exposing their loved ones to COVID-19, and 65% felt like the COVID-19 pandemic negatively impacted their training overall. Respondents indicated that changes occurred in their respective residency curricula that altered training such as canceling of scheduled lectures (84.3%) and more telemedicine visits (56.25%). There was a significant difference for postgraduate year level and the effect on rotation assignments, with more disruption to the first- and third-year residents (P = 0.03). Conclusions: The COVID-19 pandemic has had a notable impact on the perception of quality of training and mental health within family medicine. Our findings may guide programs in how to proactively target pandemic-related training challenges.

Retinal Phenotyping of a Murine Model of Lafora Disease.

Lafora disease (LD) is a progressive neurologic disorder caused by biallelic pathogenic variants in EPM2A or EPM2B, leading to tissue accumulation of polyglucosan aggregates termed Lafora bodies (LBs). This study aimed to characterize the retinal phenotype in Epm2a-/- mice by examining knockout (KO; Epm2a-/-) and control (WT) littermates at two time points (10 and 14 months, respectively). In vivo exams included electroretinogram (ERG) testing, optical coherence tomography (OCT) and retinal photography. Ex vivo retinal testing included Periodic acid Schiff Diastase (PASD) staining, followed by imaging to assess and quantify LB deposition. There was no significant difference in any dark-adapted or light-adapted ERG parameters between KO and WT mice. The total retinal thickness was comparable between the groups and the retinal appearance was normal in both groups. On PASD staining, LBs were observed in KO mice within the inner and outer plexiform layers and in the inner nuclear layer. The average number of LBs within the inner plexiform layer in KO mice were 1743 ± 533 and 2615 ± 915 per mm2, at 10 and 14 months, respectively. This is the first study to characterize the retinal phenotype in an Epm2a-/- mouse model, demonstrating significant LB deposition in the bipolar cell nuclear layer and its synapses. This finding may be used to monitor the efficacy of experimental treatments in mouse models.

Murine typhus.

Murine typhus is a rare condition caused by the gram-negative bacterium Rickettsia typhi which classically presents with the triad of fever, rash, and headache. Herein we report a rare presentation of murine typhus in an adult who presented predominantly with fever and gastrointestinal symptoms. Initial imaging showed cardiomegaly and hepatosplenomegaly, which led to further workup revealing rickettsial disease. Although this illness is considered a rare diagnosis in the emergency department, every person with a pet that might have fleas is susceptible to it.

Expression profiling of TaARGOS homoeologous drought responsive genes in bread wheat.

Drought tolerant germplasm is needed to increase crop production, since water scarcity is a critical bottleneck in crop productivity worldwide. Auxin Regulated Gene involved in Organ Size (ARGOS) is a large protein family of transcription factors that plays a vital role in organ size, plant growth, development, and abiotic stress responses in plants. Although, the ARGOS gene family has been discovered and functionalized in a variety of crop plants, but a comprehensive and systematic investigation of ARGOS genes in locally used commercial wheat cultivars is still yet to be reported. The relative expression of three highly conserved TaARGOS homoeologous genes (TaARGOS-A, TaARGOS-B, TaARGOS-D) was studied in three drought-tolerant (Pakistan-2013, NARC-2009 and NR-499) and three sensitive (Borlaug-2016, NR-514 and NR-516) wheat genotypes under osmotic stress, induced by PEG-6000 at 0 (exogenous control), 2, 4, 6, and 12 h. The normalization of target genes was done using ß-actin as endogenous control, whereas DREB3, as a marker gene was also transcribed, reinforcing the prevalence of dehydration in all stress treatments. Real-time quantitative PCR revealed that osmotic stress induced expression of the three TaARGOS transcripts in different wheat seedlings at distinct timepoints. Overall, all genes exhibited significantly higher expression in the drought-tolerant genotypes as compared to the sensitive ones. For instance, the expression profile of TaARGOS-A and TaARGOS-D showed more than threefold increase at 2 h and six to sevenfold increase after 4 h of osmotic stress. However, after 6 h of osmotic stress these genes started to downregulate, and the lowest gene expression was noticed after 12 h of osmotic stress. Among all the homoeologous genes, TaARGOS-D, in particular, had a more significant influence on controlling plant growth and drought tolerance as it showed the highest expression. Altogether, TaARGOSs are involved in seedling establishment and overall plant growth. In addition, the tolerant group of genotypes had a much greater relative fold expression than the sensitive genotypes. Ultimately, Pakistan-2013 showed the highest relative expression of the studied genes than other genotypes which shows its proficiency to mitigate osmotic stress. Therefore, it could be cultivated in arid and semi-arid regions under moisture-deficient regimes. These findings advocated the molecular mechanism and regulatory roles of TaARGOS genes in plant growth and osmotic stress tolerance in contrasting groups of wheat genotypes, accompanied by the genetic nature of identified genotypes in terms of their potential for drought tolerance.

The Influence of Static Load and Sideways Impact Fall on Extramedullary Bone Plates Used to Treat Intertrochanteric Femoral Fracture: A Preclinical Strength Assessment.

Hip fracture accounts for a large number of hospitalizations, thereby causing substantial economic burden. Majority (> 90%) of all hip fractures are associated to sideways fall. Studies on sideways fall usually involve loading at quasi-static or at constant displacement rate, which neglects the physics of actual fall. Understanding femur resonance frequency and associated mode shapes excited by dynamic loads is also critical. Two commercial extramedullary implants, proximal femoral locking plate (PFLP) and variable angle dynamic hip screw (VA-DHS), were chosen to carry out the preclinical assessments on a simulated Evans-I type intertrochanteric fracture. In this study, we hypothesized that the behavior of the implant depends on the loading types-axial static and transverse impact-and a rigid implanted construct will absorb less impact energy for sideways fall. The in silico models were validated using experimental measurements of full-field strain data obtained from a 2D digital image correlation (DIC) study. Under peak axial load of 3 kN, PFLP construct predicted greater axial stiffness (1.07 kN/mm) as opposed to VA-DHS (0.85 kN/mm), although the former predicted slightly higher proximal stress shielding. Further, with greater mode 2 frequency, PFLP predicted improved performance in resisting bending due to sideways fall as compared to the other implant. Overall, the PFLP implanted femur predicted the least propensity to adverse stress intensities, suggesting better structural rigidity and higher capacity in protecting the fractured femur against fall.

Primary care physician and resident perceptions of gun safety counseling.

A significant public health burden exists related to firearm-related injuries in the United States. Primary care physicians (PCPs) find themselves on the frontline to address it. This study aimed to determine if PCPs feel prepared and responsible for providing firearm safety counseling. Data were gathered via a direct 23-question survey of family medicine, internal medicine, and pediatric physicians and residents in North and Central Texas between May 2019 and January 2020. The survey was delivered to 518 outpatient providers, with a 24% response rate. Associations were assessed by chi-square/Fisher's exact test. A total of 62% agreed that preventable firearm death is an important health issue and PCPs can have a positive effect; 10% felt their residency provided or provides opportunities to learn about firearm safety and how to counsel patients; 55% agreed that a standardized tool to question and counsel patients on firearm safety such as a template in the electronic health record would be useful; and 68% stated they would use a standardized template in their practice if proven to reduce firearm-related injuries. Physicians who had received training in residency felt their knowledge was adequate to be able to provide meaningful counseling to patients (P < 0.001). In conclusion, PCPs are pivotal in addressing firearm safety. A formal curriculum across primary care specialties' graduate education programs should be developed to improve physicians' competency in addressing firearm safety. Further investigation into standardized tools that could be implemented into an electronic health record may help bridge the gap from awareness to implementation of interventions.

Hypomorphic GINS3 variants alter DNA replication and cause Meier-Gorlin syndrome.

The eukaryotic CDC45/MCM2-7/GINS (CMG) helicase unwinds the DNA double helix during DNA replication. The GINS subcomplex is required for helicase activity and is, therefore, essential for DNA replication and cell viability. Here, we report the identification of 7 individuals from 5 unrelated families presenting with a Meier-Gorlin syndrome-like (MGS-like) phenotype associated with hypomorphic variants of GINS3, a gene not previously associated with this syndrome. We found that MGS-associated GINS3 variants affecting aspartic acid 24 (D24) compromised cell proliferation and caused accumulation of cells in S phase. These variants shortened the protein half-life, altered key protein interactions at the replisome, and negatively influenced DNA replication fork progression. Yeast expressing MGS-associated variants of PSF3 (the yeast GINS3 ortholog) also displayed impaired growth, S phase progression defects, and decreased Psf3 protein stability. We further showed that mouse embryos homozygous for a D24 variant presented intrauterine growth retardation and did not survive to birth, and that fibroblasts derived from these embryos displayed accelerated cellular senescence. Taken together, our findings implicate GINS3 in the pathogenesis of MGS and support the notion that hypomorphic variants identified in this gene impaired cell and organismal growth by compromising DNA replication.

Promyelocytic leukemia nuclear bodies behave as DNA damage sensors whose response to DNA double-strand breaks is regulated by NBS1 and the kinases ATM, Chk2, and ATR.

The promyelocytic leukemia (PML) nuclear body (NB) is a dynamic subnuclear compartment that is implicated in tumor suppression, as well as in the transcription, replication, and repair of DNA. PML NB number can change during the cell cycle, increasing in S phase and in response to cellular stress, including DNA damage. Although topological changes in chromatin after DNA damage may affect the integrity of PML NBs, the molecular or structural basis for an increase in PML NB number has not been elucidated. We demonstrate that after DNA double-strand break induction, the increase in PML NB number is based on a biophysical process, as well as ongoing cell cycle progression and DNA repair. PML NBs increase in number by a supramolecular fission mechanism similar to that observed in S-phase cells, and which is delayed or inhibited by the loss of function of NBS1, ATM, Chk2, and ATR kinase. Therefore, an increase in PML NB number is an intrinsic element of the cellular response to DNA damage.

Abstracts from the Seventh Annual Baylor University Medical Center Medical Education Research Forum 2021.

The Baylor University Medical Center Department of Medical Education hosted its seventh annual Medical Education Research Forum on April 21, 2021, to showcase the research efforts of its medical students, residents, and fellows. Thirty-six posters were shared and 18 oral presentations were given. Here we present 17 award-winning abstracts.

Sodium taurocholate inhibits intestinal adenoma formation in APCMin/+ mice, potentially through activation of the farnesoid X receptor.

In light of clinical and biological evidence that bile constituents exert preventive effects against colorectal cancer, we evaluated the influence of oral bilirubin and sodium taurocholate (NaTC) on intestinal tumor formation in APC(Min/+) mice. Mice received bilirubin and/or bovine serum albumin (BSA) and NaTC in the drinking water for 8 weeks, after which the number, size and location of intestinal adenomas were determined. Tissue specimens were analyzed by light microscopy, TUNEL staining, immunohistochemistry for beta-catenin and Ki-67 and quantitative polymerase chain reaction for farnesoid X receptor (FXR)-dependent gene expression. Colon tumor formation also was assessed in azoxymethane (AOM)-treated hyperbilirubinemic Gunn (j/j) and wild-type (+/+) rats. Compared with untreated APC(Min/+) mice, the mean number of intestinal adenomas was markedly lower in both bilirubin (10.5 +/- 0.9 versus 37.0 +/- 5.2; +/-SEM; P < 0.001) and NaTC plus BSA (14.3 +/- 5.4; P = 0.01)-treated animals. Both treatment groups exhibited reduced levels of cellular proliferation in the ileum (by Ki-67 staining), but no differences in TUNEL staining or the percentage of beta-catenin-positive crypts. Bilirubin feeding reduced intestinal inducible nitric oxide synthase expression, but did not alter adenoma multiplicity in APC(Min/+) mice or in AOM-treated j/j versus +/+ rats. Mice receiving NaTC manifested increased intestinal expression of the FXR-regulated genes, Shp, FGF15 and IBABP, and a concomitant decrease in cyclin D1 message. Administering NaTC to APC(Min/+) mice causes a marked reduction in intestinal adenomas. We postulate that this effect is mediated through activation of FXR, leading to increased Shp expression and consequent downregulation of cyclin D1.

Spinal deformity in patients with DiGeorge syndrome.

STUDY DESIGN: Retrospective review of a case series. OBJECTIVE: To present the clinical characteristics and treatment of spinal deformity in DiGeorge syndrome. SUMMARY OF BACKGROUND DATA: There are no data on the development of spinal deformity in this condition. A high rate of wound infection could be expected after spinal surgery due to congenital thymic hypoplasia. METHODS: The medical records and spinal radiographs of 4 consecutive patients were reviewed. All patients were followed for a minimum of 2.5 years after spinal surgery. RESULTS: The mean age at diagnosis of spinal deformity was 9.9 years. The type of deformity was not uniform but the curves progressed in all patients requiring a spinal arthrodesis at a mean age of 16.1 years. Two patients developed a thoracolumbar scoliosis and underwent an anterior spinal arthrodesis with instrumentation, which produced a good outcome. The remaining 2 patients developed a double thoracic and lumbar scoliosis with increased thoracic kyphosis. Brace treatment was unsuccessful to control the deformity in one of these patients. Both patients underwent a posterior spinal arthrodesis with segmental instrumentation, which achieved satisfactory correction of the scoliosis with no loss of correction or detected pseudarthrosis at follow-up. However, both patients developed junctional kyphosis above the proximal end of the instrumentation. This was asymptomatic and nonprogressive; therefore, cephalad extension of the fusion was not required. Irradiated blood products were administered in all patients to prevent graft-versus-host disease. The postoperative course was uncomplicated and none of the patients developed wound healing problems or infections. CONCLUSIONS: The development of spinal deformity in patients with DiGeorge syndrome may be associated to the presence of marked ligamentous laxity and congenital cardiac disease. There is significant variability on the pattern of spinal deformity, which in our series was progressive in all patients and required surgical correction with no perioperative complications.

Phenotyping for drought resistance in bread wheat using physiological and biochemical traits.

Drought is one of the most prominent limiting factors that negatively affect crop productivity by manipulating its physiological pathway. One hundred twenty diverse bread wheat genotypes were used in a pot experiment to explore the relationship among their fifteen physio-biochemical traits (PBT) by using multivariate analysis, heatmapping and stress tolerance index (STI) for grain yield as a marker trait to identify high yielding genotype with maximum stress tolerance capability. Increased proline and sugar accumulation were observed from control to moisture deficient environments by 159% and 122%, respectively. Moreover, leaf membrane stability index (LMSI), leaf relative water content (LRWC), relative dry weight (RDW), chlorophyll content, leaf surface area (LSA), Leaf succulence (LS), canopy temperature depression (CTD), relative excised leaf water loss (RELWL) and leaf osmotic potential (LOP) showed significantly decreasing trend in drought stress treatment as compared to well-watered plants by -21%, -21%, -34%, -22%, -38%, -37%, -46%, -18% and -35% respectively. Additionally, principal component analysis and genotype by trait biplot analysis showed that initial 7 principal components (PC1 to PC7) represented 77.27% and 79.02% of total cumulative variation under control and drought stress respectively. Genotypic-Phenotypic correlation revealed that most of the attributes were higher in case of genotypic correlation component (rg) as compared to the phenotypic correlation component (rp) indicating more genetic association between traits. The darker and lighter colour scale produced by heatmap exhibited contrasting nature of genotypes, as positive side with higher values represented drought resistance while values on the negative side with lower values showed susceptible performance of genotypes. Our results concluded that the studied PBT associated with STI for grain yield are the main factors which may contribute in improved productivity of wheat crop and if these traits show appropriate performance under stress condition the crop will show the more productive returns under changing climate.