The process by which the Drosophila R7 photoreceptor is specified has become a classic model for understanding how cell-cell signals direct cell fates. In the R7 precursor cell, both the Notch and receptor tyrosine kinase (RTK) signaling pathways are active, and the information they encode directs the specification of the R7 photoreceptor identity. In this process, Notch performs three distinct functions: it both opposes and promotes the actions of the RTK pathway to specify the photoreceptor fate, and it determines the type of photoreceptor that is specified.
View Article and Find Full Text PDFMayo Clin Proc Innov Qual Outcomes
December 2024
A 20-year-old male underwent diagnostic testing due to unexplained shortness of breath and chest discomfort. He had no previous medical problems and was not taking any medications. Initial evaluations included cardiopulmonary exercise testing (CPET), which yielded results that were reported as normal.
View Article and Find Full Text PDFBackground: Exercise pulmonary hypertension (ePH), defined as a mean pulmonary artery pressure (mPAP)/cardiac output (Qc) slope >3 WU during exercise, is common in patients with heart failure with preserved ejection fraction (HFpEF). However, the pulmonary gas exchange-related effects of an exaggerated ePH (EePH) response are not well-defined, especially in relation to dyspnea on exertion (DOE) and exercise intolerance.
Methods: 48 HFpEF patients underwent invasive (pulmonary and radial artery catheters) constant-load (20W) and maximal incremental cycle testing.
Sevenless (Sev) is a Drosophila receptor tyrosine kinase (RTK) required for the specification of the R7 photoreceptor. It is cleaved into α and β subunits and binds the ectodomain of the G-protein-coupled receptor bride of sevenless (Boss). Previous work showed that the Boss ectodomain could bind but not activate Sev; rather, the whole seven-pass transmembrane Boss was required.
View Article and Find Full Text PDFObjective: To report the use of a Lateral Epicondylar Anatomical Plate for the management of humeral condylar fractures (HCF) in dogs.
Study Design: Medical records of dogs with HCF stabilized using the Lateral Epicondylar Anatomical Plate at six UK veterinary referral centres between April 2018 and February 2021 were reviewed. Long-term follow-up (>6 months) was obtained via owner questionnaire, which incorporated the Liverpool Osteoarthritis in Dogs clinical metrology instrument.
Objective: To use a previously validated veterinary clinical examination sheet, Liverpool Osteoarthritis in Dogs (LOAD) questionnaire, combined with kinetic and kinematic gait analysis in dogs with/without mobility problems to demonstrate the capacity of a novel clinical metrology instrument ("GenPup-M") to detect canine mobility impairments.
Design: Quantitative study.
Animals: 62 dogs (31 with mobility impairments and 31 without mobility impairments).
Heart failure with preserved ejection fraction (HFpEF) patients have an increased ventilatory demand. Whether their ventilatory capacity can meet this increased demand is unknown, especially in those with obesity. Body composition (DXA) and pulmonary function were measured in 20 patients with HFpEF (69 ± 6 yr;9 M/11 W).
View Article and Find Full Text PDFObjective: To describe the surgical treatment, postoperative management, and outcome of a miniature horse undergoing total hip arthroplasty (THA).
Study Design: Case report.
Animals: A 4-year-old miniature horse stallion weighing 85 kg.
Objective: The aim of this study was to determine the accuracy of client recollection of their dogs' preconsultation status using clinical metrology instruments such as the Liverpool Osteoarthritis in Dogs (LOAD) and Canine Brief Pain Inventory (CBPI) questionnaires in dogs presenting to a referral orthopaedic clinic.
Study Design: This is a longitudinal prospective cohort study of client-owned dogs presenting for investigations of lameness ( = 217). LOAD and CBPI questionnaires were completed by the owners at the first consultation (T0).
Objective: To report the medium and long-term outcome of nine dogs with disk-associated cervical spondylomyelopathy (DA-CSM), treated by instrumented interbody fusion using patient specific end-plate conforming device that features a micro-porous structure to facilitate bone in-growth.
Study Design: A retrospective clinical study.
Animals: Nine medium and large breed dogs.
The incidence of syncope during orthostasis increases in early human pregnancy, which may be associated with cerebral blood flow (CBF) dysregulation in the upright posture. In addition, obesity and/or sleep apnea per se may influence CBF regulation due to their detrimental impacts on cerebrovascular function. However, it is unknown whether early pregnant women with obesity and/or sleep apnea could have impaired CBF regulation in the supine position and whether this impairment would be further exacerbated in the upright posture.
View Article and Find Full Text PDFBackground: The primary cause of dyspnea on exertion in heart failure with preserved ejection fraction (HFpEF) is presumed to be the marked rise in pulmonary capillary wedge pressure during exercise; however, this hypothesis has never been tested directly. Therefore, we evaluated invasive exercise hemodynamics and dyspnea on exertion in patients with HFpEF before and after acute nitroglycerin (NTG) treatment to lower pulmonary capillary wedge pressure.
Research Question: Does reducing pulmonary capillary wedge pressure during exercise with NTG improve dyspnea on exertion in HFpEF?
Study Design And Methods: Thirty patients with HFpEF performed two invasive 6-min constant-load cycling tests (20 W): one with placebo (PLC) and one with NTG.
Background: Exercise intolerance is a defining characteristic of heart failure with preserved ejection fraction (HFpEF). A marked rise in pulmonary capillary wedge pressure (PCWP) during exertion is pathognomonic for HFpEF and is thought to be a key cause of exercise intolerance. If true, acutely lowering PCWP should improve exercise capacity.
View Article and Find Full Text PDFImportance: Military forces in the State of New York, comprising the Army National Guard, Air National Guard, Naval Militia, and State Guard, with contributions from the Army Corps of Engineers, have made major contributions to the state response to the COVID-19 pandemic.
Observations: Operation COVID-19 began on March 10, 2020, and will continue uninterrupted at least through June 2022, making it the longest and largest domestic mobilization in state history. More than 7000 service members served across 200 COVID-19 mission sites, administering more than 4 million vaccines, producing more than 35 million testing kits, delivering more than 54 million meals, and administering more than 1.
The aim of this study is to report outcomes of dogs undergoing cholecystectomy for gall bladder mucocele (GBM) without flushing and catheterization of the common bile duct (CBD). This is a retrospective multicentric study from three veterinary referral hospitals and included 82 dogs diagnosed with GBM. Medical records were reviewed for clinical and histopathological findings.
View Article and Find Full Text PDFBackground: Patients with heart failure with preserved ejection fraction (HFpEF) exhibit many cardiopulmonary abnormalities that could result in V˙/Q˙ mismatch, manifesting as an increase in alveolar dead space (VD) during exercise. Therefore, we tested the hypothesis that VD would increase during exercise to a greater extent in patients with HFpEF compared with control participants.
Research Question: Do patients with HFpEF develop VD during exercise?
Study Design And Methods: Twenty-three patients with HFpEF and 12 control participants were studied.
Heart failure with preserved ejection fraction (HFpEF) is associated with cardiopulmonary abnormalities that may increase physiological dead space to tidal volume (VD/VT) during exercise. However, studies have not corrected VD/VT for apparatus mechanical dead space (VDM), which may confound the accurate calculation of VD/VT. We evaluated whether calculating physiological dead space with (VD/VT) and without (VD/VT) correcting for VDM impacts the interpretation of gas exchange efficiency during exercise in HFpEF.
View Article and Find Full Text PDFPatients with heart failure with preserved ejection fraction (HFpEF) exhibit cardiopulmonary abnormalities that could affect the predictability of exercise [Formula: see text] from the Jones corrected partial pressure of end-tidal CO (PJ) equation (PJ = 5.5 + 0.9 × [Formula: see text] - 2.
View Article and Find Full Text PDFObesity presents a mechanical load to the thorax, which could perturb the generation of minute ventilation (V̇e) during exercise. Because the respiratory effects of obesity are not homogenous among all individuals with obesity and obesity-related effects could vary depending on the magnitude of obesity, we hypothesized that the exercise ventilatory response (slope of the V̇e and carbon dioxide elimination [V̇co] relationship) would manifest itself differently as the magnitude of obesity increases. To investigate the V̇e/V̇co slope in an obese population that spanned across a wide body mass index (BMI) range.
View Article and Find Full Text PDFObjective: To describe and report the outcomes after closure of median sternotomies with crimped monofilament nylon leader (MNL) in dogs.
Study Design: Retrospective observational study.
Animals: Dogs (n = 10) that underwent intrathoracic surgery through a median sternotomy approach.
Inherited prion diseases are caused by autosomal dominant coding mutations in the human prion protein (PrP) gene (PRNP) and account for about 15% of human prion disease cases worldwide. The proposed mechanism is that the mutation predisposes to conformational change in the expressed protein, leading to the generation of disease-related multichain PrP assemblies that propagate by seeded protein misfolding. Despite considerable experimental support for this hypothesis, to-date spontaneous formation of disease-relevant, transmissible PrP assemblies in transgenic models expressing only mutant human PrP has not been demonstrated.
View Article and Find Full Text PDFWe investigated the contributions of obesity on multidimensional aspects of dyspnea on exertion (DOE) in patients referred for clinical cardiopulmonary exercise testing (CPET). Ratings of perceived breathlessness (RPB, Borg scale 0-10) were collected in obese (BMI ≥ 30; n = 47) and nonobese (BMI ≤ 25; n = 27) patients during two (one lower: ∼30 W; and one higher: ∼50 W) 4-6 min constant load cycling bouts. Multidimensional dyspnea profiles (MDP) were collected in the final 26 obese and 14 nonobese patients of the sample.
View Article and Find Full Text PDFSevenless (Sev) is a Receptor Tyrosine Kinase (RTK) that is required for the specification of the Drosophila R7 photoreceptor. Other Drosophila photoreceptors are specified by the action of another RTK; the Drosophila EGF Receptor (DER). Why Sev is required specifically in the R7 precursor, and the exact role it plays in the cell's fate assignment have long remained unclear.
View Article and Find Full Text PDFObjective: The main aim of this study was to describe complications in dogs weighing < 20 kg treated for medial patellar luxation and to determine risk factors associated with these complications.
Materials And Methods: Medical records were reviewed and cases were grouped based on four techniques of stabilization for the tibial tuberosity transposition (TTT). Variables including animal signalment, clinical presentation, TTT technique, other concurrent surgical techniques and associated complications were investigated.