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Frontiers in Endocrinology 2024Obesity impairs bone marrow (BM) glucose metabolism. Adult BM constitutes mostly of adipocytes that respond to changes in energy metabolism by modulating their...
OBJECTIVES
Obesity impairs bone marrow (BM) glucose metabolism. Adult BM constitutes mostly of adipocytes that respond to changes in energy metabolism by modulating their morphology and number. Here we evaluated whether diet or exercise intervention could improve the high-fat diet (HFD) associated impairment in BM glucose uptake (BMGU) and whether this associates with the morphology of BM adipocytes (BMAds) in rats.
METHODS
Eight-week-old male Sprague-Dawley rats were fed either HFD or chow diet for 24 weeks. Additionally after 12 weeks, HFD-fed rats switched either to chow diet, voluntary intermittent running exercise, or both for another 12 weeks. BMAd morphology was assessed by perilipin-1 immunofluorescence staining in formalin-fixed paraffin-embedded tibial sections. Insulin-stimulated sternal and humeral BMGU were measured using [F]FDG-PET/CT. Tibial microarchitecture and mineral density were measured with microCT.
RESULTS
HFD rats had significantly higher whole-body fat percentage compared to the chow group (17% vs 13%, respectively; = 0.004) and larger median size of BMAds in the proximal tibia (815 µm vs 592 µm, respectively; = 0.03) but not in the distal tibia. Switch to chow diet combined with running exercise normalized whole-body fat percentage ( < 0.001) but not the BMAd size. At 32 weeks of age, there was no significant difference in insulin-stimulated BMGU between the study groups. However, BMGU was significantly higher in sternum compared to humerus ( < 0.001) and higher in 8-week-old compared to 32-week-old rats ( < 0.001). BMAd size in proximal tibia correlated positively with whole-body fat percentage (r = 0.48, = 0.005) and negatively with humeral BMGU (r = -0.63, = 0.02). HFD significantly reduced trabecular number ( < 0.001) compared to the chow group. Switch to chow diet reversed this as the trabecular number was significantly higher ( = 0.008) than in the HFD group.
CONCLUSION
In this study we showed that insulin-stimulated BMGU is age- and site-dependent. BMGU was not affected by the study interventions. HFD increased whole-body fat percentage and the size of BMAds in proximal tibia. Switching from HFD to a chow diet and running exercise improved glucose homeostasis and normalized the HFD-induced increase in body fat but not the hypertrophy of BMAds.
Topics: Animals; Male; Rats, Sprague-Dawley; Rats; Adiposity; Diet, High-Fat; Physical Conditioning, Animal; Bone Marrow; Glucose; Obesity; Adipocytes
PubMed: 38948514
DOI: 10.3389/fendo.2024.1422869 -
A Flow Cytometry-Based Method for Assessing CAR Cell Binding Kinetics Using Stable CAR Jurkat Cells.Bio-protocol Jun 2024Chimeric antigen receptors (CARs) are synthetic fusion proteins that can reprogram immune cells to target specific antigens. CAR-expressing T cells have emerged as an...
Chimeric antigen receptors (CARs) are synthetic fusion proteins that can reprogram immune cells to target specific antigens. CAR-expressing T cells have emerged as an effective treatment method for hematological cancers; despite this success, the mechanisms and structural properties that govern CAR responses are not fully understood. Here, we provide a simple assay to assess cellular avidity using a standard flow cytometer. This assay measures the interaction kinetics of CAR-expressing T cells and targets antigen-expressing target cells. By co-culturing stably transfected CAR Jurkat cells with target positive and negative cells for short periods of time in a varying effector-target gradient, we were able to observe the formation of CAR-target cell doublets, providing a readout of actively bound cells. When using the optimized protocol reported here, we observed unique cellular binding curves that varied between CAR constructs with differing antigen binding domains. The cellular binding kinetics of unique CARs remained consistent, were dependent on specific target antigen expression, and required active biological signaling. While existing literature is not clear at this time whether higher or lower CAR cell binding is beneficial to CAR therapeutic activity, the application of this simplified protocol for assessing CAR binding could lead to a better understanding of the proximal signaling events that regulate CAR functionality. Key features • Determines CAR receptor cellular interaction kinetics using a Jurkat cell model. • Can be used for a wide variety of CAR target antigens, including both hematological and solid tumor targets. • Experiments can be performed in under two hours with no staining using a standard flow cytometer. • Requires stable CAR Jurkat cells and target cells with stable fluorescent marker expression for optimal results.
PubMed: 38948258
DOI: 10.21769/BioProtoc.5021 -
Frontiers in Physiology 2024Proximal tubule (PT) cells maintain a high-capacity apical endocytic pathway to recover essentially all proteins that escape the glomerular filtration barrier. The multi...
Proximal tubule (PT) cells maintain a high-capacity apical endocytic pathway to recover essentially all proteins that escape the glomerular filtration barrier. The multi ligand receptors megalin and cubilin play pivotal roles in the endocytic uptake of normally filtered proteins in PT cells but also contribute to the uptake of nephrotoxic drugs, including aminoglycosides. We previously demonstrated that opossum kidney (OK) cells cultured under continuous fluid shear stress (FSS) are superior to cells cultured under static conditions in recapitulating essential functional properties of PT cells . To identify drivers of the high-capacity, efficient endocytic pathway in the PT, we compared FSS-cultured OK cells with less endocytically active static-cultured OK cells. Megalin and cubilin expression are increased, and endocytic uptake of albumin in FSS-cultured cells is > 5-fold higher compared with cells cultured under static conditions. To understand how differences in receptor expression, distribution, and trafficking rates contribute to increased uptake, we used biochemical, morphological, and mathematical modeling approaches to compare megalin traffic in FSS- versus static-cultured OK cells. Our model predicts that culturing cells under FSS increases the rates of all steps in megalin trafficking. Importantly, the model explains why, despite seemingly counterintuitive observations (a reduced fraction of megalin at the cell surface, higher colocalization with lysosomes, and a shorter half-life of surface-tagged megalin in FSS-cultured cells), uptake of albumin is dramatically increased compared with static-grown cells. We also show that FSS-cultured OK cells more accurately exhibit the mechanisms that mediate uptake of nephrotoxic drugs compared with static-grown cells. This culture model thus provides a useful platform to understand drug uptake mechanisms, with implications for developing interventions in nephrotoxic injury prevention.
PubMed: 38948083
DOI: 10.3389/fphys.2024.1404248 -
Cureus May 2024Proximal femur fractures are common in older patients and typically require surgical treatment, with cephalomedullary nails being the gold standard device for this...
INTRODUCTION
Proximal femur fractures are common in older patients and typically require surgical treatment, with cephalomedullary nails being the gold standard device for this approach. This study aimed to identify the factors associated with the failure of cephalomedullary nailing.
MATERIALS AND METHODS
We retrospectively evaluated 380 patients treated with a cephalomedullary nail between August 2021 and August 2022 in a trauma referral center in Brazil. A total of 221 (58.1%) patients were included in the study after applying specific eligibility criteria. Data were collected and rates were determined by reviewing patients' medical records and radiographs.
RESULTS
Of 221 patients, 14 (6.3%) had nail failures A significant association was found between post-fixation cervico-diaphyseal angle and the occurrence of nail failure (p<0.001). Furthermore, calcar-referenced tip-apex distance (CalTAD) and tip-apex distance (TAD) values were higher in cases with nail failure than in those without nail failure. Cutoff points were established for TAD and CalTAD to measure the correspondence with nail failures.
CONCLUSION
The present study supports previous evidence that varus reduction potentially causes collapse and nail failure in pertrochanteric fractures treated with cephalomedullary nailing and that high TAD and CalTAD values contribute to the incidence of cut-out.
PubMed: 38947728
DOI: 10.7759/cureus.61363 -
Cureus May 2024Coronary artery disease continues to remain the leading cause of mortality worldwide. Coronary blood supply is provided through the right and left main coronary...
Coronary artery disease continues to remain the leading cause of mortality worldwide. Coronary blood supply is provided through the right and left main coronary arteries. The left main coronary artery (LMCA) in turn gives rise to the left anterior descending (LAD) and left circumflex (LCX) arteries. In some cases, LMCA may trifurcate into the ramus intermedius (RI) in addition to the LAD and LCX arteries. Atherosclerotic plaque formation and rupture with subsequent clot formation and occlusion of coronary arteries are the underlying mechanisms of myocardial infarction. Though the clinical implications of the presence of ramus intermedius (RI) are controversial some data suggest that the RI is associated with an increased risk of atherosclerotic plaque formation in the LMCA and the proximal LAD. Conversely, it has been proposed that the RI provides an additional collateral source of blood supply to the myocardium and may potentially contribute to improved survival. Case reports tout the benefits of RI, specifically in the setting of multivessel coronary artery occlusions. Whether it increases the risk of atherosclerotic plaque formation or whether it is protective has yet to be determined. We present a case of a 58-year-old male who presented with acute coronary syndrome and cardiogenic shock due to total ostial occlusion of LAD. The patient had also chronic total occlusions of the right coronary artery and LCX but a patent RI, which was the only source of blood supply to the myocardium and practically determined the patient's survival. Additionally, we performed a literature review to identify similar cases, to support RI's potentially protective role in enhancing survival.
PubMed: 38947610
DOI: 10.7759/cureus.61288 -
ACS Central Science Jun 2024The proximitome is defined as the entire collection of biomolecules spatially in the proximity of a biomolecule of interest. More broadly, the concept of the proximitome... (Review)
Review
The proximitome is defined as the entire collection of biomolecules spatially in the proximity of a biomolecule of interest. More broadly, the concept of the proximitome can be extended to the totality of cells proximal to a specific cell type. Since the spatial organization of biomolecules and cells is essential for almost all biological processes, proximitomics has recently emerged as an active area of scientific research. One of the growing strategies for proximitomics leverages reactive species-which are generated in situ and spatially confined, to chemically tag and capture proximal biomolecules and cells for systematic analysis. In this Outlook, we summarize different types of reactive species that have been exploited for proximitomics and discuss their pros and cons for specific applications. In addition, we discuss the current challenges and future directions of this exciting field.
PubMed: 38947200
DOI: 10.1021/acscentsci.4c00373 -
Research Square Jun 2024Interstitial cells of Cajal (ICC) and PDGFRα cells regulate smooth muscle motility in the gastrointestinal (GI) tract. However, their role(s) in esophageal motility...
Interstitial cells of Cajal (ICC) and PDGFRα cells regulate smooth muscle motility in the gastrointestinal (GI) tract. However, their role(s) in esophageal motility are still unclear. The mouse esophagus has traditionally been described as almost entirely skeletal muscle in nature though ICC have been identified along its entire length. The current study evaluated the distribution of skeletal and smooth muscle within the esophagus using a mouse selectively expressing eGFP in smooth muscle cells (SMCs). The relationship of SMCs to ICC and PDGFRα cells was also examined. SMCs declined in density in the oral direction however SMCs represented ~ 25% of the area in the distal esophagus suggesting a likeness to the transition zone observed in humans. ANO1 intramuscular ICC (ICC-IM) were distributed along the length of the esophagus though like SMCs, declined proximally. ICC-IM were closely associated with SMCs but were also found in regions devoid of SMCs. Intramuscular and submucosal PDGFRα cells were densely distributed throughout the esophagus though only intramuscular PDGFRα cells within the LES and distal esophagus highly expressed SK3. ICC-IM and PDGFRα cells were closely associated with nNOS , VIP , VAChT and TH neurons throughout the LES and distal esophagus. GFAP cells resembling intramuscular enteric glia were observed within the muscle and were closely associated with ICC-IM and PDGFRα cells, occupying a similar location to motor nerve fibers. These data suggest that the mouse esophagus is more similar to the human than thought previously and thus set the foundation for future functional and molecular studies using transgenic mice.
PubMed: 38947055
DOI: 10.21203/rs.3.rs-4474290/v1 -
IDCases 2024Hydatidosis, is a zoonotic disease prevalent in sheep-raising regions globally. Musculoskeletal hydatidosis is uncommon and usually remains asymptomatic over a long...
Hydatidosis, is a zoonotic disease prevalent in sheep-raising regions globally. Musculoskeletal hydatidosis is uncommon and usually remains asymptomatic over a long period. The detection of musculoskeletal hydatidosis often signifies extensive cyst spread within the bone marrow cavity, making treatment difficult with a high recurrence rate. Unlike the conventional surgical approach for visceral hydatid cysts, treating osseous hydatidosis requires a strategy akin to oncologic therapy. We report a rare case of primary hydatidosis affecting the ulna and adjacent soft tissue in a 58-year-old woman. She presented with a painless forearm mass evolving over six years, accompanied by recent onset tenderness and restricted elbow joint mobility. Imaging revealed a cystic mass in the forearm, an intra-ulnar bone lesion, and an olecranon fracture. The primary diagnosis of musculoskeletal hydatidosis was made based on clinical findings and radiological imaging. Treatment involved resection of 2/3 of the proximal ulna and pericystectomy for the soft tissue hydatid cyst. Diagnosis of musculoskeletal hydatidosis is vital for effective preoperative planning, as internal fixation often fails without eradicating the infestation. Treatment typically involves radical operation with wide excision of the affected bone and adjacent joint structures, coupled with chemotherapy. Clinicians in endemic regions should consider musculoskeletal hydatidosis in the differential diagnosis of osteolytic lesions and slow-growing cystic masses. Diagnosis relies on clinical, serological, and radiological assessments.
PubMed: 38946938
DOI: 10.1016/j.idcr.2024.e01994 -
Arthroplasty Today Jun 2024This study aimed to investigate the relationship between 3-dimensional (3D) alignment and postoperative bone mineral density (BMD) changes with Accolade II tapered wedge...
BACKGROUND
This study aimed to investigate the relationship between 3-dimensional (3D) alignment and postoperative bone mineral density (BMD) changes with Accolade II tapered wedge stems, which have a different proximal shape from other tapered wedge stems, up to 5 years after primary total hip arthroplasty.
METHODS
We retrospectively analyzed the hips of 89 patients who underwent total hip arthroplasty using the second-generation proximally coated cementless stem (Accolade II; Stryker Orthopedics, Mahwah, NJ) at our institution from 2014 to 2018 over a 5-year follow-up. We evaluated the relationship between stem alignment, measured using 3D-templating software, and BMD changes in the 7 Gruen zones and compared the data with those from a former study using other short taper-wedge stems.
RESULTS
BMDs in zones 1 and 7 continued to decrease gradually every year after surgery, and BMD in zone 7 showed the largest decrease (21%) from baseline over 5 years. No correlation was found between stem alignment (varus/valgus, flexion/extension, and anteversion/retroversion) and changes in BMD in each zone over 5 years.
CONCLUSIONS
Our data showed no correlation between 3D stem alignment and changes in BMD in each Gruen zone over 5 years. This suggests that the Accolade II stem may fit better into any shape of the proximal medullary canal because of its unique characteristics.
PubMed: 38946925
DOI: 10.1016/j.artd.2024.101433 -
Case Reports in Women's Health Jun 2024Pain after vaginal prolapse repair surgery with mesh is generally attributed to the mesh fixation, particularly to mesh erosion, dislocation or the development of...
Pain after vaginal prolapse repair surgery with mesh is generally attributed to the mesh fixation, particularly to mesh erosion, dislocation or the development of hematoma. However, once all the causes have been excluded, the urinary system, bladder and ureters should be accurately examined by means of endovaginal ultrasound. This report concerns the case of a 72-year-old woman who had undergone mesh-supported prolapse surgery 3 months prior, with no other relevant diseases, who visited the emergency department complaining of dull, right-sided colic pain. The endovaginal ultrasound examination revealed a prevesical ureteral calculus on the right side with consequent dilatation of the proximal ureter. Computed tomography of the abdomen and pelvis confirmed the calculus in the distal right ureter and revealed a right renal lower pole calculus. The patient underwent treatment via an operative ureterorenoscopy with removal of stones and placement of a double-J-stent. Two months later, a second ureterorenoscopy was performed with double-J-stent removal and concomitant stone extraction. It appears that no similar cases have been reported in the literature. This is why, during the urogynecological postoperative follow-up, it is of paramount importance to examine the entire urogenital system with endovaginal ultrasound. This case report highlights how, through a simple, non-invasive, radiation-free examination, like ultrasound, most of the post-operative complications of vaginal prolapse repair surgery using mesh, including urolithiasis, can be excluded.
PubMed: 38946844
DOI: 10.1016/j.crwh.2024.e00627