bluuebunny/crossref_metadata_2025 huggingface dataset:
A High Fat diet containing Fish oil reduces weight gain and metabolic syndrome associated with glucocorticoid therapy
Authors: van der Merwe Marie , Beech LeeAnna , Godwin Simone , Buddington Randy , Ringwald‐Smith Karen
Published: November 2023

Obesity and metabolic syndrome are now recognized as significant health concerns for survivors of pediatric Acute Lymphoblastic Leukemia (ALL) and are consequences of their treatment. The majority of weight gain occurs during the induction phase of therapy (first 28 days), when patients receive various chemotherapies in addition to high dose glucocorticoids. Physiological levels of glucocorticoids are required for metabolic control, but chronic exposure to elevated doses has been linked to metabolic disease including type 2 diabetes and obesity. Nutrition plays an important role in the development of obesity and is also amongst the few adjustable parameters in the treatment of pediatric ALL. We therefore determined if a diet high in omega‐3 fatty acids provided by fish oil can reduce the weight gain and metabolic syndrome phenotype associated chronic high dose glucocorticoid treatment. 3 week old C57BL/6 male mice were fed a “Western type” diet (45% calories from fat (lard) (HFL)) ad libitum. At 6 weeks of age, mice received the synthetic glucocorticoid, Prednisolone, at a dose of 40 mg/m2/day for 28 days. During the Prednisolone treatment, mice either remained on the HFL diet or were switched to an isocaloric diet containing 45% fat from fish oil (HFO). Body weight, food consumption, fat deposition in the liver, accumulation of epididymal adipose tissue and adipocyte size were determined. Mice on the HFO diet gained less weight during the treatment period (P = 0.03), with a dramatic decrease in fat deposition in the liver irrespective of glucocorticoid treatment. Epididymal adipose depots were smaller in mice consuming the HFO diet (P < 0.0001) with a concomitantly decrease in systemic Leptin levels (P = 0.05). Interestingly, glucocorticoid therapy caused a significant increase in adipocyte size when the mice are consuming the HFL diet (P = 0.001). The results from this study suggest that a dietary intervention in the form of fish oil during glucocorticoid treatment can reduce weight gain and metabolic syndrome and reduce long term consequences of ALL treatment.

Support or Funding Information

FY16 Faculty Research Grant (University of Memphis)
Validation of a Sodium Screener in Two Samples
Authors: Tangney Christy C , Rasmussen Heather C , Rusch Jesse , Moss Olivia , Cerwinske Leah A , Richards Candace , Li Michelle , Appelhans Bradley M
Published: November 2023

Assessing adherence to a reduced sodium diet through 24‐hour urinary sodium analysis or repeated 24‐hour diet recalls is both costly and burdensome for patients. In effort to reduce burden, a brief Sodium Screener© (SS) was developed by NutritionQuest (Berkeley, CA) with scores ranging from 0 to 67 and higher scores reflecting higher sodium intakes. We evaluated the validity of the SS against a criterion method, repeated 24‐hour recalls, in two contexts: (1) 102 registered dietitians (RDs; 98 women) who completed three nonconsecutive Automated Self‐Administered 24‐hour Recalls (ASA24™‐2014) and then the SS (all online), and (2) 69 community participants (59 women) who had three 24‐hour recall (Nutrition Data System for Research 2015) interviews conducted by RDs or trained assistants and then completed the SS on paper. Descriptive statistics and correlations were performed using SPSS version 22 (IBM, 2013). In the RD sample, SS sodium scores ranged from 11–54, SS‐predicted sodium intake was 2581 ± 962 (mean ± SD), and ASA24™ derived sodium intakes averaged 3157 ± 902 mg/day (energy, 1811 ± 483 kcal/day). Sodium intakes from the two methods were correlated (energy‐adjusted, r=0.23, p=0.02; unadjusted, r=0.30, p=0.003). In the community sample, SS sodium scores ranged from 1–57, SS‐predicted sodium intake were 3086 ± 1240 mg, and sodium intakes based on averaged diet recalls were 2940 ± 1238mg/day (energy, 1943 ± 632 kcal/day). Energy‐adjusted or unadjusted sodium intakes correlated with SS‐predicted sodium estimates (r=0.28, p=0.02; r=0.44, p<0.001, respectively). Pending correction of recalls for within‐person error, further evaluation of the screener may be indicated.
Inactive Matrix Gla Protein is Associated with Arterial Stiffness and Vascular Endothelial Function in African‐American Hemodialysis Patients
Authors: Fain Mary Ellen , Nguyen Joshua , Kapuku Gaston K , Paulson William D , White John J , Dong Yanbin , Pollock Norman K
Published: November 2023

Pulse wave velocity (PWV), a marker of aortic stiffness, and brachial artery flow‐mediated dilation (FMD), a measure of endothelial dysfunction, are both independent predictors of future cardiovascular disease (CVD) events and mortality. Given that end‐stage renal disease patients receiving hemodialysis are at marked increased risk for CVD combined with recent data suggesting that African Americans (AA) are three times more likely to experience kidney failure, it is vital to identify modifiable CVD related factors that could represent therapeutic targets in this population. Matrix Gla protein (MGP) is a vascular calcification inhibitor that needs vitamin K to be activated, and recent evidence suggest that higher circulating levels of inactive MGP, known as dephospho‐uncarboxylated MGP (dp‐ucMGP), are linked to CVD events and mortality. Currently, the relationship between inactive MGP and markers of arterial stiffness and endothelial function has not been investigated in AA hemodialysis patients. This study was conducted 1) to compare plasma levels of dp‐ucMGP between AA hemodialysis patients and age‐ and race‐matched controls; and 2) to determine associations of dp‐ucMGP with PWV and FMD in the cohort of AA hemodialysis patients. Fasting plasma dp‐ucMGP concentrations, carotid‐femoral PWV by applanation tonometry, and brachial artery FMD by ultrasound were measured in 37 AA hemodialysis patients (mean age: 47.7 ± 10.4 years). Thirty‐seven AA adults without renal disease (mean age: 47.7 ± 7.4) served as controls for plasma dp‐ucMGP levels. Plasma dp‐ucMGP levels were significantly higher in hemodialysis patients compared to controls (2129 ± 1117 vs. 382 ± 181 pmol/L, P < 0.01). In analyses with multivariate linear regression adjusting for age, sex, body mass index, and mean arterial pressure, PWV (β = 0.42) and FMD (β = −0.52) were associated with dp‐ucMGP (both P < 0.01). These data suggest that higher levels of dp‐ucMGP found in AA hemodialysis patients may be associated with increased arterial stiffness and endothelial dysfunction. Experimental trials are needed to determine whether vitamin K supplementation slows arterial stiffening and endothelial dysfunction by increasing MGP carboxylation.

Support or Funding Information

Georgia Regents University's Intramural Grant Program
Redundant role of catenins in maintaining tight junctional integrity
Authors: Pradhan‐Sundd Tirthadipa , Zhou Lili , Jiang An , Russell Jacquelyn Olivia , Singh Sucha , Poddar Minakshee , Ranganathan Sarangarajan , Nejak‐Bowen Kari , Monga Satdarshan Singh Pal
Published: November 2023

Adherens Junctional Complex (AJC) consisting of catenins and cadherins adhere the neighbouring cells by linking the actin cytoskeleton. B‐Catenin, a member of the catenin family, is required for cell‐cell adhesion as well as for canonical Wnt signaling. We have shown that loss of β‐catenin from the AJCs between adjacent hepatocytes or of g‐catenin from desmosomes, are well‐tolerated. In the present study we generated and characterized mice with liver‐specific knockout of β and γ‐catenin. Here, we used albumin‐cre and double floxed‐b‐catenin‐g‐catenin mice to generate hepatocyte and cholangiocyte specific double knockouts (DKO). These animals showed failure to thrive, increased morbidity and 80% of mice die in the first month after birth. The DKO mice exhibited increased serum bilirubin, alkaline phosphatase and cholesterol and mimicked progressive familial intrahepatic cholestasis (PFIC) like phenotype with inflammation, fibrosis and ductular reaction shown by histology and biochemical studies. Furthermore, AAV8‐cre mediated deletion of b‐ and g‐catenin from hepatocytes only, showed notable irregularities in serum and histology similar to DKOs. Next, we analyzed liver samples from PFIC patients (n=8). One patient showed substantial reduction of both β‐ and γ‐catenin proteins, along with loss of association to E‐cadherin. Molecular and histochemical analysis revealed significant reduction in expression of tight junction protein claudin‐2 and occludin, in both DKO mice and patient's samples. Thus, we have identified a notable cross talk between the catenins and TJ proteins which may be of essence in barrier function in the liver. Profound understanding of this regulation of tight junction protein stability by catenins will be useful in the context of liver developmental and pathophysiology.

Support or Funding Information

This research is supported by NIH. The presenting author is supported by T32 post doctoral training programme grant number 5T32DK063922‐13.
Vesicle fusion protein, YKT6, is a novel regulator of epithelial cell‐matrix adhesion and migration
Authors: Ivanov Andrei , Naydenov Nayden , Joshi Supriya , Feygin Alex
Published: November 2023

Epithelial cell migration is a key regulatory element of a variety of biological and pathological processes, including embryonic morphogenesis, tissue repair, and tumor metastasis. This is a multistage process involving epithelial cell adhesion to the extracellular matrix (ECM) and remodeling of the cortical cytoskeleton. Trafficking of ECM adhesion proteins and other membrane and signaling proteins to the migrating cellular edge plays an essential role in regulating cell motility. YKT6 is a key component of the vesicle fusion machinery that regulates ER‐Golgi trafficking, however its functions in cell migration remain uninvestigated. In this study, we found that siRNA‐mediated knockdown of YKT6 in DU145 and p69 human prostate epithelial cells significantly accelerated planar cell migration in a wound closure assay and 3‐D cell invasion into Matrigel. These effects were accompanied by a significant increase in cell adhesion to ECM and cell spreading. Immunoblotting analysis of different focal adhesion proteins revealed two vivid effects of YKT6 knockdown. One effect was defective Golgi‐dependent glycosylation of β1‐integrin while the other involved decreased levels of phosphorylated paxillin. However, subsequent experiments demonstrated that neither of these effects is responsible for the increased motility of YKT6‐depleted cells. We also investigated the effects of YKT6 knockdown on the expression of cell‐cell adhesion proteins and observed a marked and selective increase in the expression of Junctional Adhesion Molecule A (JAM‐A) protein. Given the known pro‐migratory role of JAM‐A in different cell types, we probed JAM‐A upregulation to determine if it could mediate the increased motility of YKT6‐depleted cells. Co‐knockdown of JAM‐A and YKT6 reversed the accelerated migration of DU145 cells caused by YKT6 depletion. Since JAM‐A can promote epithelial cell migration by activating Rap1 small GTPase, we next investigated if Rap1 activity mediates the increased motility of YKT‐6 depleted epithelial cells. We observed that pharmacological Rap1 inhibitor, GGTI 298, reversed the accelerated wound healing in YKT6‐depleted epithelial cell monolayers. These results reveal a novel role for YKT6 in limiting epithelial cell migration via mechanisms involving the suppression of the JAM‐A‐Rap1 signaling nexus.

Support or Funding Information

Supported by NIH grants DK083968 and DK084953 to AII and by the Crohn's and Colitis Foundation of America grant 254881 to NGN.
The Specialized Pro‐resolving Lipid Mediator Resolvin E1 Promotes Intestinal Mucosal Wound Repair
Authors: Quiros Miguel , Nishio Hikary , Leoni Giovanna , Agarwal Rachit , Bernal Gabriela , Gerner‐Smith Christian , Colas Romain , Graham Kareem , Serhan Charles , Garcia Andres , Parkos Charles , Nusrat Asma
Published: November 2023

Resolution of inflammation and wound healing are active processes that are required to repair the epithelial barrier at mucosal surfaces following injury. Protein/peptides and lipid mediators referred to as specialized pro‐resolving mediators (SPM) play an important role in the reparative response. Resolvin E1 (RvE1), a SPM derived from omega‐3 fatty acids has been reported to decrease the inflammatory response and promote repair. Using an endoscopic biopsy‐based wound healing model, we observed increased RvE1 synthesis in healing wounds. Delayed intestinal mucosal wound closure was observed in mice lacking the RvE1 G protein coupled receptor Chemokine Like Receptor 1 (CMKLR1). Complimentary in vitro experiments demonstrated that RvE1 treatment of model intestinal epithelial cells promoted wound repair by increasing epithelial cell proliferation through activation of the mTOR signaling pathway. Furthermore, in‐vivo local administration of RvE1‐encapsulated synthetic nanoparticles into healing intestinal wounds promoted mucosal wound repair. Together, our results support a therapeutic role of RvE1 in facilitating intestinal mucosal wound repair

Support or Funding Information

CCFA

NIH
Sympathetic Signaling Regulates Cardiomyocyte Cohesion via the Plaque Protein Plakoglobin
Authors: Schinner Camilla , Schlipp Angela , Rötzer Vera , Vielmuth Franziska , Messoudi Ahmed , Horn Anja , Spindler Volker , Waschke Jens
Published: November 2023

The intercalated disc (ICD), composed of desmosomes, adherens junctions and gap junctions, provides the structural backbone for coordinated contraction and structural integrity of the heart. Recently we have reported sympathetic signaling to regulate cell cohesion of cardiomyocytes. Increased cAMP levels strengthened desmoglein 2 (Dsg2)‐mediated adhesion paralleled with a reorganization of the ICD. Here we demonstrate this adrenergic effect to be strictly dependent on the plaque protein plakoglobin (Pg). Similar to Dsg2, Pg staining was enhanced along intercellular junctions following adrenergic stimulation, while distribution of other desmosomal proteins was not altered. Silencing Pg abrogated cAMP‐dependent enhancement of Dsg2‐mediated binding events at cell junctions as revealed by atomic force microscopy (AFM). To further investigate the role of Pg, we established a cardiac specific Pg knock‐out (Pg KO) mouse model. Deleting Pg blocked the positive effect of adrenergic stimulation on cardiomyocyte cohesion and prevented the positive inotropic and chronotropic impact of sympathetic signaling in the ex vivo Langendorff setting. Furthermore, ICDs of Pg KO hearts challenged by adrenergic stimulation were ruptured compared to challenged wild type hearts. Interestingly, in Pg KO hearts all other ICD components were present whereas Dsg2 was selectively reduced before onset of dilatation and fibrosis. These data indicate that strengthening of cell cohesion via Pg and Dsg2 is required for a sufficient response to adrenergic stimulation and maintenance of ICD integrity. Because reduction of Pg at the ICD has been reported to be a feature of arrythmogenic cardiomyopathy, this mechanism may be of high medical relevance.
Insulin treatment increases myocardial ceramide accumulation and disrupts cardiometabolic function
Authors: Hodson Aimee E. , Tippetts Trevor S. , Bikman Benjamin T.
Published: November 2023

States of hyperinsulinemia, particularly insulin resistance and type 2 diabetes mellitus, are becoming remarkably common, with roughly half a billion people likely to suffer from the disorder within the next 15 years. Along with this rise has been an associated increased burden of cardiovascular disease. Considering type 2 diabetics treated with insulin are more likely to suffer from heart complications, we sought to determine the specific effect of insulin and insulin‐induced ceramide accrual on heart mitochondrial bioenergetics. H9c2 cardiomyocytes and adult male mice were treated with insulin with or without myriocin to inhibit ceramide biosynthesis. Mitochondrial bioenergetics were determined in permeabilized cardiomyocytes and myocardium. Herein, we demonstrate that insulin is sufficient to disrupt heart mitochondrial respiration in both isolated cardiomyocytes and whole myocardium. Further, insulin increases ceramide accrual in a time‐dependent manner, which is necessary for insulin‐induced alterations in heart mitochondrial respiration. Collectively, these observations have two implications. First, they indicate a pathological role of insulin in heart complications stemming from mitochondrial disruption. Second, they identify ceramide as a possible mediator of insulin‐related heart disorders.
Mitochondrial Fission is Necessary for Ceramide‐induced Metabolic Disruption
Authors: Bikman Benjamin T.
Published: November 2023

Fat gain is associated with ceramide accrual in tissues of high‐metabolic rate, such as liver, brain and skeletal muscle. Ceramide has long been known to affect mitochondrial function, including morphology, in its activation of apoptosis, however, little has been done to determine the metabolic effects of ceramide on mitochondria. Of the myriad mediators that may reduce skeletal muscle capacity, potentially reducing activity and leading to increased weight gain, the particular effects of the sphingolipid ceramide on skeletal muscle mitochondria may provide a novel perspective and solution. Muscle cells and permeabilized muscle fibers were treated with palmitate to induce endogenous ceramide biosynthesis or treated with ceramide directly. In parallel, treatments included inhibition of de novo ceramide synthesis as well as inhibition of mitochondrial fission (via pharmacological and genetic blockade). Lastly, mitochondrial dynamics were determined in muscle from mice following dietary challenge. Ceramide treatment on murine myotubes induced mitochondrial fission via increased dynamin‐related protein 1 (Drp1). Drp1 inhibition (via Mdivi) prevented ceramide‐induced fission, as well as protected mitochondrial respiration in ceramide‐treated permeabilized mouse red gastroc. While treatment of myoblasts with C2‐ceramide reduced mitochondrial respiration, inhibition of fission via Drp1 blockade (i.e. siRNA) resulted in maintained respiration (data not shown). Additionally, though ceramide is known to block insulin signaling via Akt targeting, inhibition of mitochondrial fission prevented ceramide‐induced insulin resistance, revealing a novel mechanism. Mice fed a high‐fat, high‐sugar (HFHS) diet experienced robust increases in ceramides and mitochondrial fission, but not with ceramide inhibition. Altogether, these findings suggest a critical role for ceramide in altering mitochondrial dynamics with subsequent altered metabolic function, including mitochondrial respiratory function and insulin signaling. Importantly, inhibition of ceramide biosynthesis may provide a therapeutic target to maintain mitochondrial function and reduce risk of obesity‐related diseases.
Augmented Adipocyte Browning and Mitochondrial Function in Periadrenal Fat but not Subcutaneous Fat in Pheochromocytoma Patients
Authors: Davies Graeme Robert , Vergnes Laurent , Yeh Michael , Harari Avital , Livhits Masha , Huang Jiaoti , Symonds Michael , Reue Karen , Sacks Harold
Published: November 2023

Background and aims

This study aimed to characterize browning in periadrenal (pADR) and subcutaneous adipose tissue (SAT) depots in humans with pheochromocytoma

Methods

pADR and abdominal SAT samples were collected from patients undergoing adrenalectomy for aldosterone, cortisol‐secreting and non‐functioning neoplasms for the study control group (n=23) and patients with benign unilateral pheochromocytoma (n=15). Plasma catecholamine levels were measured by HPLC. The presence of unilocular or multilocular adipocytes was assessed by H&E staining and brightfield microscopy. UCP1 abundance was measured at the gene expression level by qPCR and protein by immunohistochemistry and western blotting. Mitochondria were isolated from the tissue samples and respiration analysed on an XF24 Seahorse Extracellular Flux Analyzer. Whole transcriptome analysis was carried out in pADR fat by Illumina microarray.

Results

60% (9/15) of the pheo group showed browning of periadrenal fat recorded by the presence of multilocular adipocytes. Interestingly, those patients with browning in pADR fat had the highest levels of plasma catecholamines. Control pADR fat samples showed no multilocular adipocytes. No patients in either control or pheo groups showed browning of SAT. This was corroborated with UCP1 protein found in multilocular pADR fat in pheos but not in SAT. Pheo patients with multilocular pADR fat had increased mitochondrial respiration in pADR compared to controls or pheos with unilocular adipocytes. Specifically, we detected higher complex 1 to 4 respiration of the electron transport chain, while uncoupled respiration was higher. No difference was observed in respiration from SAT mitochondria. No increase was seen in plasma ANP, BNP or FGF21 in pheo patients compared to controls. Finally, microarray analysis in pADR revealed a distinct gene expression signature in pheo patients with multilocular adipocytes, characterized by enhanced expression of genes required for fatty acid oxidation and mitochondrial respiration.

Conclusions

Browning of pADR occurs in some patients with pheochromocytoma but is not observed in SAT. This browning may be driven by elevated plasma nor‐epinephrine in these subjects. Our data demonstrates for the first time that the multilocular pADR adipose tissue observed in pheo patients has increased mitochondrial respiration, suggesting potentially significant effects on energy metabolism in vivo.

Support or Funding Information

Funded by the Leducq Foundation and the Cardiometabolic Research Foundation, Los Angeles
Recommended anthropometric cut‐offs for population screening of diabetes and prediabetes need to be evaluated in resource‐limited settings
Authors: Yu Elaine A , Finkelstein Julia L. , Bonam Wesley , Glesby Marshall J. , Brannon Patsy M. , Mehta Saurabh
Published: November 2023

Background

Globally, waist circumference (WC) and body mass index (BMI) are widely used for population screening to predict disease risk, including for diabetes. We examined the association of anthropometric measurements with diabetes and pre‐diabetes in a cohort where the majority of participants would be classified as low risk based on either BMI or WC.

Methods

Study participants were recruited from an outpatient clinic in rural South India (n=297). Concentrations of glycosylated hemoglobin (HbA1c) were measured by high‐performance liquid chromatography. Diabetes and pre‐diabetes were defined as HbA1c ≥6.5% and ≥5.7% to <6.5%, respectively. Waist circumference was measured by non‐stretch measuring tape to the nearest 0.1 cm by study staff. Whole and segmental body composition were measured by bioelectrical impedance analysis (8 electrode; Tanita BC 418 MA). Binomial regressions were used to assess the associations between diabetes (and pre‐diabetes), and anthropometric indicators (WC, BMI). Restricted cubic splines were used to evaluate non‐linearity.

Results

Mean waist circumference was 73.2 cm (SD: 11.3) among males, and 69.7 cm (SD 12.1) among females. Among male study participants, more than 90% had a waist circumference < 90 cm; among females, 80% had a waist circumference <80 cm. Mean BMI was 19.2 kg/m2 (SD 4.1) among men, and 20.4 kg/m2 (SD 5.4) among women. Among males, 50.0% had BMI <18.5 kg/m2, and over 90% had BMI <25.0 kg/m2. Among females, nearly 50% of study participants had BMI <18.5 kg/m2, and more than 80% had BMI <25.0 kg/m2. Study participants with waist circumference in the two lowest tertiles had a lower risk of diabetes (Tertile 1 vs 3: RR 0.40 [95% CI 0.20–0.81]; Tertile 2 vs 3: RR 0.33 [95% CI: 0.15–0.73]), compared to those in the highest tertile (p=0.004). Waist circumference was not associated with pre‐diabetes; BMI was not associated with either diabetes or pre‐diabetes.

Conclusion

Based on widely used cutoffs of WC and BMI (World Health Organization, International Diabetes Federation for South Asia), nearly 90% of study participants would be considered to be at low or minimal risk for diabetes. However 13% of study participants had diabetes, and 21% had pre‐diabetes. Waist circumference was still associated with increased risk of diabetes among study participants. These findings emphasize the need for the development of population‐specific cutoffs for waist circumference in diabetes screening.

Support or Funding Information

Cornell University
Vitamin A Supplementation Only Transiently Increases Retinol Concentrations in Extrahepatic Organs of Neonatal Rats Raised under Vitamin A‐Marginal Conditions
Authors: Urbanek J. Kalina , Tan Libo , Green Michael H. , Ross A. Catharine
Published: November 2023

Vitamin A (VA, retinol) supplementation is recommended for children > 6 mo old in countries with high rates of malnutrition, based on the positive results of clinical trials conducted in the 1990s. However, the results of studies on the benefits of supplementing neonates < 5 mo old are inconsistent. The objective of this study was to determine the distribution of VA in bodies of neonatal rats raised under VA‐marginal conditions (control group) and the effect of VA supplementation on the concentration and mass of retinol in the body, including plasma, liver, and lungs, as well as several understudied extrahepatic organs, such as the brain, brown adipose tissue, and skin.

Methods

Neonatal rats (n = 103), nursed by mothers fed a VA‐marginal diet, were randomized and treated on postnatal day 4 (P4) with an oral dose of either VA (6 μg retinyl palmitate/g body weight) or canola oil as control. Subsequently, pups (n = 4/group/time) were euthanized at 13 time points from 30 min to 24 d after dosing and the following organs were collected: plasma, liver, lungs, kidneys, stomach, intestine, brain, white and brown adipose tissue, skin, and the remaining carcass. The total retinol concentration and mass in each organ was measured with ultra‐performance liquid chromatography.

Results

Control pups maintained a marginal plasma VA concentration, while the VA concentration in the liver was deficient. Despite its deficient status, the liver contained most (~77%) of the whole‐body VA mass, similarly as in previous studies of adult rats with an adequate liver VA concentration. White adipose tissue, which was nearly absent prior to P12, contained only ~1% of the whole‐body VA mass, compared to 10–20% reported in adult rats. The remaining extrahepatic, non‐digestive organs together stored < 10% of the whole‐body retinol mass. VA supplementation significantly increased total retinol concentrations in all organs. However, this increase lasted for only 1 d in most extrahepatic organs, with the exception of white adipose tissue, where it lasted for 18 d.

Conclusions

Our findings suggest that extrahepatic organs in neonatal rats may not be sufficiently developed to store VA at the adult capacity and that the scarcity of adipose tissue may predispose neonates to a low VA status. Moreover, given the transient effect of VA supplementation on extrahepatic organs, a more frequent supplementation schedule, along with other nutrition interventions, may be necessary to maintain a steady supply of retinol to the rapidly developing extrahepatic organs.

Support or Funding Information

Supported by NIH grant HD‐066982
Comparative Cardiac Anatomy and Transmyocardial Laser Revascularization
Authors: Cabral Richard Halti
Published: November 2023

Comparative cardiac anatomy related to the analysis of the initial clinical experience of transmyocardial laser revascularization (tmlr) in patients with severe diffuse coronary artery disease.

methods

20 patients were submitted to tmlr at the heart institute (incor), university of são paulo medical school, brazil, isolated or in association with conventional coronary artery bypass graft (cabg). all patients had severe diffuse coronary artery disease, with angina functional class iii/iv (canadian cardiovascular society score) unresponsive to medical therapy. fourteen patients were submitted to tmlr as the sole therapy, whereas 6 underwent concomitant cabg. fifty per cent of the patients had either been previously submitted to a cabg or to a percutaneous transluminal coronary angioplasty (ptca). mean age was 60 years, ranging from 45 to 74 years.

results

all patients had three‐vessel disease, with normal or mildly impaired left ventricular global function. follow‐up ranged from 1 to 13 months (mean 6.6 months), with no postoperative short or long term mortality. there was significant symptom improvement after the procedure, with 85% of the patients free of angina, and the remaining 15 % of the patients showing improvement in functional class, as well as in exercise tolerance.
Sodium Overload Induces Remodeling of Aorta and Cardiac Arteries Without Blood Pressure Changes in Mice
Authors: Lacchini Silvia , Silva Juliane Cristina Souza , Lima Cintia Taniguti , da Silva Viegas Katia Aparecida , Oliveira Thais Cristina Souza , Fiorino Patricia , de Moura Azevedo Farah Vera , Cabral Richard Halti
Published: November 2023

Sodium intake is considered an important mechanism of cardiovascular stress, and can lead to the development of pathologies as hypertension. Hypertension is a well‐known determinant of structural and functional changes of arteries. It is unclear if the effect of salt overload is related to the described hypertension or if there are other mechanisms involved.

The objective of this study was to evaluate the effect of sodium overload upon wall structure of elastic and muscular arteries in normotensive male and female mice. For this, 4 weeks age male and female C57Bl/6 mice were divided into 3 groups (n=8 to 10 for each group): control, drinking normal water (cont), treated with 1% NaCl solution for 2 weeks (salt‐2) or 12 weeks (salt‐12). Body weight was measured at weeks 4, 6, 8, 10 and 12, and at the end of the study were also measured pulse blood pressure (BP) and heart rate (HR) by tail plethysmography. Before tissue collection, water ingestion, urine volume and sodium excretion were measured by using metabolic cages. Then, aorta and heart were collected, prepared for histological analysis, and sections (5μm) were stained by Verhoeff‐Van Gieson for analysis of arterial thickening, by picrosirius for analysis of perivascular collagen deposition, and by Weigert for elastic lamellae analysis. The results were compared by ANOVA, using p≤0.05 as significant.

At the end of the experiment, we did not observe differences between groups when we compare body weight, BP and HR. Water ingestion (salt‐2M:+95; salt‐12M:+100%), urine volume (salt‐2M:+107; salt‐12M:+114%), and sodium excretion (salt‐2M:+281; salt‐12M:+164%) increased in salt treated mice, particularly in males. Elastic lamellae in aorta increased in females after salt overload (salt‐2F:+20%; salt‐12F:+40%). Interestingly, perivascular collagen deposition in cardiac arteries reduced in salt‐treated males (salt‐2M:−50%; salt‐12M:−55%). On the other hand, aorta collagen deposition increased, both in males (salt‐2M:+26%; salt‐12M:+40%), and females (salt‐2F:+20%; salt‐12F:+80%).

The lack of changes in BP and HR suggest that the structural changes observed are not directly related to hemodynamic mechanisms. Morphometric results suggest that sodium overload induces adaptive responses in different fashion in male and female mice, indicating a possible artery thickening in female as consequence of salt chronic ingestion.

Support or Funding Information

FAPESP, CAPES and CNPq
Supernumerary Sutures in the Zygoma and their Impacts on Skull Modularity and Biomechanics
Authors: Wang Qian C. , Dechow Paul C.
Published: November 2023

Craniofacial sutures are weak points compared to rigid bone on the skull and hence must be shielded from unduly high stresses so as not to disrupt vital growth processes and skeletal functions, especially in areas such as the midface. Under rare circumstances, extra sutures may naturally present in the midface, an area of critical morphological and biomechanical importance, such as intrazygomatic sutures dividing the zygoma into multiple parts (incidence of up to 6.5% in modern human populations, 0.24% in rhesus macaques, and 4.4% in orangutans). However, how these extra sutures would impact the ontogeny and function of facial skeletons has not been systematically studied. In this study, using 3D images and a Finite Element Model simulating the condition of the divided zygoma, the morphological and biomechanical influences of the supernumerary sutures in the midface were investigated. In skulls with unilateral divided zygoma, the bone was transected by the supernumerary intrazygomatic suture that arises perpendicularly from the facial aspect of the maxillo‐zygomatic suture and runs dorsolaterally, separating the zygoma into a superior division and an inferior division (bipartite). When compared to the normal side, the superior division was slender with the weaker muscle/fascia attachment markings on the frontal process, while the inferior division was more robust, with a thicker temporal process. The bones on the affected side that articulated with the inferior division also demonstrated signs of bony strengthening, including a thicker zygomatic process of the temporal bone contributing to a more robust zygomatic arch, and thickening of the lateroinferior part of the zygomatic process of the maxillary bone. Biomechanical simulations revealed that the superior division was spared high stress flow in the normal condition at the expense of the inferior division. In this way, the stresses incurred during normal masticatory activities were shunted from the upper face to the lower face, especially along the zygomatic arch, which is heavily stressed during normal conditions, suggesting that the bipartite morphology is less optimal than the typical case. These findings revealed that the divided zygoma condition would alter overall morphology of the midface of the affected side, and unfavorably affect the pattern of stress distribution in the loaded side of the face during mastication. This suggests that the presence of supernumerary sutures disturbs the integrity and modularity of zygomatic development leading to consequent morphological and functional adaptations. Further insights into this rare condition may deepen our understanding of craniofacial form, adaptation, and evolution, and help to improve therapeutic philosophies in corrective and regenerative medicine.
Cranial Fibrous Connective Tissue Joints and Experiments in their Growth
Authors: Byron Craig D.
Published: November 2023

Cranial sutures and periodontal ligaments (PDL) are fibrous connective tissue articulations found between intramembranous bones and teeth of the vertebrate cranium. Growth and remodeling of these tissues is believed to be partially regulated by biomechanical loading patterns that include stresses relating to chewing. Masticatory advances in the structure and function of the cranium that enabled mammalian‐style chewing is commonly tied to the origins and evolution of this group. Such oral processing is an advantageous feeding behavior that often involves an individual handling a food item in the mouth while it is probed, tested, and reduced. To what degree masticatory overuse or underuse shapes the complexity and ossification around these articulations can be predicted based on prior experimental and comparative work. Here I report on a mouse model system that has been used to experimentally manipulate dietary material properties, label bone formation, and investigate central nervous system proprioceptive tissues of the cranial fibrous joints. All animal use has been conducted in conformance with the FASEB Statement of Principles for the use of animals in research and education. Treatment groups were fed diets of contrasting material properties, such as dry and powderized (with and without pumice added), gelatin, and enhanced pelleted rodent chow. Animals were raised from weaning to adulthood and calvarial suture morphology as well as sites of bone formation within the PDL were compared between groups. Predicted intergroup variation is observed in body mass, masticatory muscle mass, and mandibular corpus size suggesting that masticatory overuse is associated with muscle and bone growth. Cranial suture complexity is not as obviously impacted in this experiment because the masticatory underuse category also had more complex sutures. Regions of bone formation around the molar PDL in the mandibular corpus did not show any clear pattern of contrast between groups. The counterintuitive results from the cranial sutures indicate a confounding factor in this study. One such factor likely includes masticatory stress that results from other types of non‐dietary strains, like chewing on cage surroundings (e.g., metal wires). Nevertheless, treatment groups were different in many morphological aspects and this probably results from the contrasting patterns (either magnitudes, frequency, or both) of chewing behavior that occurs during diets with diverse and enriching material properties. To what degree the mammalian central nervous system receives sensory input from these ligaments that help to coordinate chewing kinematics is unknown. A possible method for answering this question is presented.
Transcriptional Control of Cranial Suture Development
Authors: Maxson Robert , Teng Camilla , Ting Manchun , Crump Gage
Published: November 2023

The skull is a complex, exquisitely patterned structure with key roles in many aspects of vertebrate life, ranging from the acquisition of food to the support of the sense organs for hearing, smell, sight, and taste. During its development it must meet the dual challenges of protecting the brain and accommodating its growth. The flat bones at the top of the skull compose the skull vault, or calvaria. Between the bones are sutures, fibrous joints that allow the skull vault to flex during childbirth and act as a growth center in postnatal growth and homeostasis. A number of congenital disorders affect the development of the skull vault. Prominent among these is Saethre‐Chotzen syndrome is a disorder characterized by premature fusion of the bones of the skull vault (craniosynostosis) and facial irregularities. Heterozygous mutations in the basic helix‐loop‐helix (bHLH) transcription factor TWIST1 account for roughly 71% of Saethre‐Chotzen syndrome diagnoses. Recently, patients with Saethre‐Chotzen syndrome who do not carry TWIST1 mutations were found instead to have mutations in TCF12, another bHLH gene. Suggesting an interaction between these genes, loss of Tcf12 enhances craniosynostosis in Twist1+/− mice. Marker analysis in individual and compound Twist1 and Tcf12 mutants suggests that these two genes cooperatively control a set of downstream processes, including the specification of sutural cells as well as the boundary between osteogenic and non‐osteogenic cells at the coronal suture. To further explore the role of Twist1 and Tcf12 in suture development, we have developed a zebrafish model of suture development that appears to closely mimic mammalian sutures. Using TALEN‐mediated mutagenesis, we have generated null alleles for both zebrafish Twist1 homologs (twist1a and twist1b) and tcf12. Remarkably, a portion of zebrafish doubly null for twist1b and tcf12 are adult viable yet display near complete loss of the coronal suture. Our data provide strong evidence for deep evolutionary homology of the coronal suture between fish and mammals, thus suggesting that the zebrafish will be a useful model for understanding craniosynostosis in humans.

Support or Funding Information

This work was supported by grants from the NIH (NIDCR) to RM, CT, and GC
Prediction, Performance, and Adjustments: Medical Students’ Reflections on the First Gross Anatomy Exam
Authors: Hoffman Leslie A.
Published: November 2023

Background

Studies have found that lower performing medical students tend to exhibit over‐confidence when it comes to predicting exam performance. This overconfidence typically stems from a lack of awareness of their knowledge deficits.

Purpose

The purpose of this study was to assess medical students’ accuracy in predicting their grade on the first gross anatomy exam, as well as to examine how they planned to adjust their study habits based on their actual exam performance.

Methods

First‐year medical students (n=30) were asked to asked to reflect on their study habits and confidence level prior to the first gross anatomy exam. They were also asked to indicate the grade they expected to receive on the exam. Following the exam, students reflected on their exam performance, how their confidence level has changed, and what adjustments they planned to make to their study habits. The students’ grade predictions were also compared to their actual exam performance.

Results

Following the exam, students were divided into three groups based on their performance: High performers, average performers, and low performers. The low performers (n=9) all received a failing grade on the exam (< 70%). There were no significant differences in the grade predictions between the three groups, although all of the low performing students overestimated their grade. Qualitative analysis of students’ proposed adjustments to their study habits revealed that high performing students intended to adjust their study habits in focused and content‐specific ways, such as spending more time on radiology or clinical correlations, while their overall strategies remained largely unchanged. Low performing students frequently indicated that they intended to change their overall study strategy as a result of their exam performance, for example, by incorporating more quizzing, studying with peers, or spending more time preparing for lecture and lab so that time spent in class yielded higher level learning.

Discussion

This study reinforces observations that low performing students are often unaware of their knowledge deficits. These findings also suggest that many low performing students had not developed basic study habits prior to entering medical school and often engage in trial and error to discover which study strategies work best for them. These low performing students would likely benefit from an introductory study skills course early on in their medical training.
Remediation in an Integrated Medical School Curriculum ‐ Lessons Learned
Authors: Ward Peter
Published: November 2023

Medical schools are finding that curricular reform and adoption of integrated curricular designs are expected by their accrediting bodies. From a faculty perspective, curricular reform can be a relatively traumatic event that is often mandated but rarely embraced. Faculty members’ immediate concern is typically the conservation or pruning of content as it moves from well‐defined disciplines (e.g. anatomy, pharmacology, pathology) to a novel place in more obscure categories such as back pain, nausea, fever, etc. In addition to re‐ordering the content, a task that is akin to assembling a new picture from an existing jigsaw puzzle, there are often expectations that more topics will be delivered outside of lecture. Inclusion of team‐based sessions, application exercises, or via flipped‐classroom sessions bring additional challenges to teaching faculty. In the process of implementing a new curricular scheme, some important aspects are only considered after the content has been put into place. One of these concerns is how to remediate students after a course failure. This session will focus on how remediation can be conducted in a longitudinal curriculum by showcasing the challenges that were identified and addressed at the West Virginia School of Osteopathic Medicine.

WVSOM adopted a longitudinal, patient‐presentation curriculum starting in the 2012–13 academic year. We found that the previous remediation process and resources were inadequate to meet the needs of remediating students in the new curricular arrangement. We also discovered that sensible and seemingly‐minor changes made during the academic year sometimes had unintended consequences for remediation. This session will show how deficiencies in the remediation process were identified, how they were remedied, and will finish by presenting our revised remediation process. Remediation is intended to strengthen the curriculum by maintaining high standards of our students and they work through content that challenged them on the first attempt. The revised remediation process at WVSOM accomplishes these goals by limiting the number of courses that can be remediated, provides resources to the students that are commensurate with the way content had been delivered during their regular courses, gives them opportunities to diagnose weaknesses in their learning, and then address those weaknesses through Q&A sessions with the teaching faculty.

Support or Funding Information

No extramural or other grant funding was used during preparation of this session. The presenter has no conflicts of interest to report.
Differences in Anterior Cruciate Ligament Fiber Orientation Between Digitigrade and Palmigrade Animals
Authors: Ruth Aidan Alifair , Hieironymus Tobin , Lovejoy C. Owen
Published: November 2023

In humans, the Anterior Cruciate Ligament (ACL) is divided into two main bundles; the Anteromedial (AM) and Posterolateral (PL). We sought to determine whether similar ACL divisions occur in animals with differing locomotion. We explored the gross detailed ACL anatomy in 22 mammalian species with both standard and quantitative polarized light microscopy. Traditional light microscopy with picrosirius red staining revealed that the ACL could not be divided into distinct bundles in most palmigrade mammals, including most primates. However, digitigrade animals (Tiger) and especially unguligrade mammals (deer) displayed distinct ultrastructure with demonstrable separation of at least two distinct bundles. Quantitative polarized light microscopy showed that in animals without such ultrastructural divisions, the ACL showed greater directional diversity. That is, the greater the separation between ACL sub‐bundles, the less variation occurred in fiber orientation. These results suggest that the ACL of palmigrade animals, which require a greater range of motion at the knee joint, in turn require more differentiation of fiber orientation and length than do digitigrade mammals, and thus display more “blended,” coalescent bundles.