bluuebunny/crossref_metadata_2025 huggingface dataset:
Abnormal regulation of NCC in glucocorticoid receptor haploinsufficient mice
Authors: Ivy Jessica Ruth , Evans Louise C , Richardson Rachel V , Flatman Peter W , Chapman Karen E , Kenyon Christopher J , Bailey Matthew A
Published: June 2021

Glucocorticoids can regulate ion transport in the aldosterone sensitive distal nephron (ASDN). Glucocorticoid receptor (GR) polymorphisms are associated with hypertension but the mechanism for this is unclear. We found GR heterozygous mice (GR+/−) have elevated basal blood pressure (P<0.01), which is salt‐sensitive (P<0.05). GR is expressed in the distal convoluted tubule (DCT) and glucocorticoids can affect the sodium chloride cotransporter's (NCC) activity. By measuring thiazide‐sensitive NaCl transport we found that NCC reabsorbs ~2% filtered Na load in wild‐type and GR+/− mice in vivo. When challenged with a high salt diet, thiazide‐sensitive transport was reduced in wild type, but not GR+/− mice. NCC can be activated by phosphorylation of threonine (T53 & T58) and serine (S71) residues in the transporter's N‐terminus. However, we found no differences in the levels of either total NCC, or of its key phosphorylated forms, pT58 and pS71, between genotypes. These data indicate that although inappropriate NCC activity contributes to salt‐sensitive hypertension in GR haploinsufficeincy, sustained NCC activity is not reflected by changes in NCC's phosphorylation status.
Basal secretion is significantly reduced in the ob/ob mouse jejunum compared to lean controls
Authors: Al‐Nakkash Layla , Leung Lana , Kang Jonathan , Rayyan Esa , Bhakta Ashesh , Barrett Brennan , Wilson David , Tamura Leslie , Corbell Kathryn , Broderick Tom L.
Published: June 2021

In the ob/ob leptin‐deficient mouse the role of intestinal secretion is unclear. The goal of this study was to characterize jejunal function. We measured transepithelial short circuit current (Isc), across jejunum from ob/ob and lean mice (aged 14 weeks). Basal Isc was significantly decreased in the ob/ob mice (50.5±9.5 μA/cm2, n=5) compared to lean mice (95.2±20.3 μA/cm2, n=4, P<0.05). The Isc in response to forskolin (10 μM, bilateral) was similar in both groups, indicating a comparable cAMP‐dependent Isc. The Isc in response to bumetanide (100 μM, basolateral) and to acetazolamide (100 μM, bilateral) was similar for both groups, indicating analogous Cl− and HCO3− secretory components. Crypt depth was similar for both groups, indicating that structural changes do not contribute towards the reduced Isc of the ob/ob mice. Villi length was significantly increased (~100 μm) in the ob/ob mice, suggesting a greater surface area for absorptive function. Expression of the transporter protein, Glut5 (normalized to GAPDH), was significantly increased 2‐fold in ob/ob mice. These data suggest that basal jejunal Isc in ob/ob mice is ~1/2 that of lean mice, and may reflect a reduced fluidity of the jejunal content in the ob/ob mice, which may contribute to the associated diabetic phenotype. Current studies aim to determine whether the contribution of key epithelial transporters is similarly reduced in the ob/ob mice.
Ugonin J, a bioactive compound isolated from Helminthostachys zeylanica (L) Hook. (Helminthostachyaceae), demonstrates inhibitory effects on neointima formation in the rat carotid artery
Authors: Wu Chieh‐Hsi , Yeh Wan‐Ting , Li Pei‐Chung
Published: June 2021

The clinical value of percutaneous coronary angioplasty (PTCA) for treating arterial obstruction has always been counteracted by neointimal hyperplasia. Development of restenosis has been attributed to abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). The purpose of the present study was to investigate whether Ugonin J, a bioactive compound isolated from Helminthostachys zeylanica (L) Hook. (Helminthostachyaceae), has potential effects to prevent neointimal formation, and to explore its molecular mechanisms. Our current findings demonstrated that at 12, 24 and 36 μM Ugonin J markedly inhibited cell growth and migration of VSMCs (A7r5). Cytometric analysis suggested that Ugonin J arrest VSMCs in the G1 phase at 36 μM. Ugonin J was able to suppress the activities of matrix metalloproteinase (MMP)‐2 and MMP‐9 in a concentration‐dependent manner. Ugonin J was also found to decrease the expression levels of p‐AKT, p‐ERK1/2, p‐FAK, ERP57, PGK1, PI3K and MMP‐2 and MMP‐9, whereas the total protein levels of AKT, ERK1/2 and FAK were not significantly changed. Our data demonstrated that Ugonin J can be a potential regulator to inhibit cell migration and neointimal formation in clinical restenosis after PTCA.
Modulation of respiratory motor output during micturition is dependent on level of respiratory drive
Authors: Shen Tabitha , Collins William F , Witkin Joanna E , Mannino Angelo , Solomon Irene C
Published: June 2021

The goal of this study was to examine the interaction between micturition reflexes and respiratory motor output in rats. To this end, phrenic nerve, abdominal muscle, and external urethral sphincter activity were recorded in urethane‐anesthetized, vagotomized, ventilated adult female Sprague‐Dawley rats during passive bladder filling and spontaneous bladder contractions (voiding) elicited by infusion of physiological saline into the bladder. Respiratory drive was controlled by altering ventilation rate and monitored through blood gases. Phrenic and abdominal activities were both influenced by micturition particularly during and after active bladder contraction. Specifically, at low to medium levels of respiratory drive (i.e., close to apneic threshold) the amplitude and frequency of phrenic bursts transiently decreased immediately following bladder contraction. At high levels of respiratory drive phrenic bursts were largely unaffected by bladder contraction whereas abdominal muscles were activated exhibiting tonic activity during and phasic (expiratory) activity following bladder contraction. Thus, multiple respiratory motor outputs are modulated during micturition and the degree of modulation is sensitive to the level of respiratory drive. Supported by HL63175 and NS049310.
Inactivity‐induced phrenic motor facilitation (iPMF) requires atypical PKCζ activity within phrenic motor neurons
Authors: Baertsch Nathan Andrew , Shires Joel A , Baker‐Herman Tracy L
Published: June 2021

Reduced respiratory neural activity elicits a rebound increase in phrenic amplitude once respiratory neural activity is restored, a form of spinal plasticity termed inactivity‐induced phrenic motor facilitation (iPMF). We tested the hypothesis that the zeta isoform of atypical PKC (PKCζ) is necessary within phrenic motor neurons (PMNs) for iPMF. Rats received bilateral intrapleural injections of siRNA (Sieck et al., 2012; EB Abstract #1147.2) targeting PKCζ (30ul of 100pmol siRNA/side) once daily for 3 days to knock down PKCζ expression specifically within phrenic motor neurons. Control rats received a non‐targeting siRNA. The fourth day, rats were anesthetized and mechanically ventilated; the phrenic nerve was prepared for electrophysiological recordings. After baseline phrenic amplitude was established, respiratory neural activity was reversibly suppressed for 30min by hyperventilating until phrenic activity ceased. 60min following restoration of baseline conditions, rats treated with control injections expressed significant iPMF (82±19 %baseline, p<0.05), whereas iPMF was significantly attenuated (13±10 %baseline, p>;0.05) in siPKCζ treated rats. PKCζ knockdown was confirmed within ventral cervical spinal segments containing PMNs with western blot analysis (−31±3 %control; p<0.05). These data indicate that expression of PKCζ specifically within PMNs is necessary for iPMF. NIH105511
A Stochastic and Integrative Model of Human Breathing
Authors: BuSha Brett , Banis George
Published: June 2021

The integration of central drive and respiratory‐related feedback imparts stochastic and temporally‐correlated behaviors into the breath‐to‐breath (BBI) interval. The objective of this study was to design a stochastic and integrative model of breathing (SIMB) that replicated the natural random and fractal‐like pattern of BBI. During quiet wakefulness and two progressive levels of exercise, 7 female and 7 male subjects wore a resistive belt to record changes in chest circumference. BBI data were identified using a locally designed peak detection algorithm. For each BBI sequence, a 28 bin BBI histogram was constructed, and then modeled with a 6th order polynomial curve. A computational memory function was optimized using autocorrelation analysis of the original BBI sequences. SIMB sequences were generated by randomly sampling intervals from each distribution model, and then applying the computational memory function. Temporal correlations were quantified using detrended fluctuation analysis (DFA). The SIMB generated BBI sequences that contained significant temporal scaling that were validated through the random shuffling of the BBI sequences (p < 0.001). Additionally, the SIMB and human data were quantitatively similar in fractal‐scaling. In conclusion, the new SIMB successfully reproduced the distribution and fractal properties found in normal adult breathing during rest and exercise.
Localizations of 11ß‐hydroxysteroid dehydrogenase type 2 and mineralocorticoid receptors in the rat hypothalamus
Authors: Wilson Remi Aleaha , Shelton Lee G. , Haque Masudul , Wandrey Narine E.J. , Wilson Lori L , Teruyama Ryoichi
Published: June 2021

Mineralocorticoid receptor (MR) was found in vasopressin (VP) and oxytocin (OT) synthesizing magnocellular neurosecretory cells (MNCs) in the paraventricular nucleus (PVN) and the supraoptic nucleus (SON) in the hypothalamus. Aldosterone exerts its biological effect via MR; however, glucocorticoids also have high binding affinity to MR and substantially higher concentrations than aldosterone concentrations in the brain. An enzyme, 11β‐hydroxysteroid dehydrogenase type 2 (11β‐HSD2), converts glucocorticoid into inactive metabolites that increases aldosterone selectivity. The presence of 11β‐HSD2 has been identified in the hypothalamus; however, the specific cell types are not known. The present study which used immunocytochemical and single‐cell RT‐PCR techniques, was conducted to elucidate whether 11β‐HSD2 and MR are co‐localized in VP and OT synthesizing MNCs. Double immunofluorescence confocal microscopy demonstrated that MR and 11β‐HSD2 immunoreactivities were found in both VP‐ and OT‐immunoreactive MNCs. In addition, MR and 11β‐HSD2 mRNAs were detected in cDNA libraries derived from single MNCs. Co‐localization of MR and 11β‐HSD2 in VP and OT MNCs suggests that aldosterone directly affects the activity of VP and OT neurons through MR.

NIH grant: R21 HL093728
CL316,243, a Selective β3‐Adrenoceptor Agonist Activates Protein Synthesis Through mTOR/p70S6K Signaling Pathway in L6 Cells.
Authors: Miniaci Maria Concetta , Irace Carlo , Santamaria Rita , Bucci Mariarosaria , Cantalupo Anna , Cirino Giuseppe , Scotto Pietro
Published: June 2021

The existence of β3‐adrenergic receptors (AR) in skeletal muscle has been demonstrated by the detection of the β3‐mRNA and protein and by the selective effects β3‐AR agonists on metabolic oxidation and glucose utilization. However, the role of β3‐AR on protein metabolism in skeletal muscle remains still unclear. To determine whether β3‐AR regulates protein translation we evaluated in L6 skeletal muscle cells the effect of CL316,243, a selective β3‐AR agonist, on the rate of protein synthesis and on the activation of the Akt/mTOR/ p70S6K signaling pathway which is known to support the protein synthesis requirement during muscle growth. When L6 cells were incubated in the presence of CL 316,243, we observed a net increase of [35S] methionine incorporation into muscle cell proteins such myosin heavy chain and myosin light chain at 24 hr. The anabolic effect of CL 316,243 was associated with an increase of p70S6K which was inhibited by the β3‐AR antagonist, SR 59230A, but not by the β2‐AR antagonist ICI 118551. In addition, the increase in p70S6K levels induced by CL 316,243 was inhibited by wortmannin, a PI3K inhibitor, and by rapamycin, mTOR inhibitor suggesting that β3‐AR regulates protein synthesis via PI3K/Akt/ p70S6K signaling pathway. This finding unveils a new cellular mechanism by which β‐AR system exerts anabolic actions on skeletal protein metabolism and therefore regulates skeletal muscle mass.
A comparison of medical student and undergrad study skills in anatomy lab courses
Authors: Barger J. Bradley , Husmann Polly
Published: June 2021

Anatomy lab courses form a crucial yet challenging part of the curriculum for medical students and many undergraduates. There is a pervasive and destructive opinion that memorization is the only skill needed for success in anatomy courses. The instructors in our anatomy courses spend a lot of time trying to change this opinion. This research uses a survey to investigate the study habits of our students, and compare these skills to final course grades.

In this study we surveyed a group of medical students and undergraduate students from two institutions about their study skills for anatomy lab exams. These study skills were then compared to the final grades in the course to find which skills correlate most strongly with success in learning lab content, as defined by final grades. Medical students do appear to use more effective learning strategies, but also spend more total hours studying for anatomy. We plan to show these results to future semester of undergrads to help them plan their studying. While this may not break the memorization paradigm, it will suggest more useful ways to spend study hours for anatomy.

Grant Funding Source: none
Effect of RAS inhibition on ACE activity in Plasma, Kidney and the Heart of Syrian Cardiomyopathic Hamster.
Authors: El Musa Laurianne , Cruz Nildris , Altieri Pablo I. , Cangiano Jose L. , Escobales Nelson , Crespo Maria J.
Published: June 2021

Previous studies of RAS inhibition in Syrian cardiomyopathic hamsters (SCH) using the renin inhibitor aliskiren (10 mg/kg/day) suggested that the kidney at variance with the heart, is resistant to renin inhibition. RAS inhibition induces compensatory increases in ACE activity in target tissues. Thus, we hypothesized that ACE in kidney homogenates, is relatively insensitive to treatment with aliskiren in contrast to those from heart and plasma. To test this hypothesis, ACE activity was determined in plasma, heart and kidney homogenates, from 6‐month‐old SCH treated over 5 months with aliskiren, valsartan (AT1receptor blocker), and these drugs in combination. Age‐matched golden hamsters were used as controls (CT). ACE activity was determined, using a fluorimetric assay. Compared to CT, basal ACE activity in SCH is higher in the kidney, heart and plasma by 12% (P<0.05), 93% (P<0.05) and 12% (P<0.05), respectively. Neither aliskiren nor valsartan changed ACE activity in the heart, kidney or plasma of SCH. The combination of these drugs however, increase ACE activity only in SCH hearts (30%, P<0.05). These results suggest that the differential ACE activity that occurs in the heart, kidney, and plasma of SCH after RAS suppression may explain the observed differences in organ protection in this animal model. The reason for these differential effects of aliskiren is unknown. Supported by MBRS‐RISE R25‐GM061838.
Skeletal muscle protein degradation induced by high‐fat diet is decreased by macadamia oil supplementation: Role of E3 ubiquitin enzyme ligase MuRF‐1 and atrogin‐1
Authors: Hirabara Sandro M , de Sousa Luis G O , Rodrigues Carlos F , Martins Amanda R , Neto Jose C Rosa , Rodrigues Alice C , Lima Edson A , Gorjao Renata , Pithon‐Curi Tania C , Curi Rui
Published: June 2021

This study aimed to assess the effect of macadamia oil (MO) on expression of genes involved in proteolytic pathways (Murf‐1 and Atrogin‐1) in diet‐induced obese C57/BL6J mice. Mice were fed a control or a high‐fat diet (HFD) and supplemented or not with MO (2.5 mg/kg) for eight weeks. mRNA levels of MuRF‐1 and atrogin‐1/MAFbx were evaluated in EDL muscle by real‐time PCR. Mice fed a HDF presented decreased EDL weight when compared to control diet (0.28 vs 0.39, respectively), suggesting muscle atrophy. MO supplementation decreased this effect (0.28 vs control 0.34; p<0.05). A significant two‐fold increase in mRNA levels of MuRF‐1 and atrogin‐1/ MAFbx, in EDL muscle, was found in mice fed a HFD. On the other hand, MO supplementation restored mRNA levels of Murf‐1 and Atrogin‐1 in mice fed a HFD to control levels, suggesting a protective effect on the pathways involved in the HFD‐induced proteolysis. Our data suggest that the increased skeletal muscle degradation induced by HDF is decreased by MO supplementation by a mechanism that involves reduced RNAm expression of Murf‐1 and Atrogin‐1. Support: FAPESP, CNPq, CAPES, Dean's Office for Research/USP, Clear, INOD, and NEL.
Beneficial effects of Compound 21 on islet mass and β‐cell functions in streptozotocin‐induced diabetic rats
Authors: Shao Chunhong , Yu Li , Gao Lie
Published: June 2021

This study evaluated the protective effects of Compound 21 (C21), an AT2R agonist, on islet function in streptozotocin (STZ)‐induced diabetic rats. 24 male rats were assigned into 3 groups: normal (N), control diabetes mellitus (C‐DM), and C21 treated DM (C21‐DM). Experiments lasted 2 weeks. N rats did not receive any treatment. C‐DM rats received a single injection of STZ at day 7. C21‐DM rats were subcutaneously infused with C21 (0.3 mg/kg/day) during the entire 14 day period and received a single injection of STZ at the day 7. At day 14, islet cell functional parameters and islet cell morphology were determined. We found that, compared with DM rats, C21‐DM rats displayed higher body weight, lower water intake and urine excretion, lower daily blood glucose (369 ± 24 vs 418 ± 36 mg/dl, P < 0.05), lower blood glucose in the fasting state (251.5 ± 9.8 vs 318.7 ± 13.9 mg/dl) and after oral glucose loading (301.5 ± 11.5 vs 405.7 ± 15.2 mg/dl, P < 0.05), higher blood insulin concentration in both fasting and after oral glucose loading. We observed increased islet cell number and islet cell volume. However, none of these parameters completely normalized. In addition, we found that C21 pretreatment suppressed STZ‐induced apoptosis and increased viability in INS‐1E cells, a β‐cell line. These data suggest beneficial effects of C21 on STZ‐induced diabetic rats via protecting islet function by suppressing β‐cell apoptosis.
Glutamine Transporter Expression Profiling Reveal Major Role for ASCT2 and LAT1 in Primary and Metastatic Human Hepatocellular Carcinoma Cells
Authors: Kron Clare , Bode Barrie
Published: June 2021

A concerted effort is underway to identify metabolic or physiological derangements in hepatocellular carcinoma (HCC) that may offer targets for therapy. While past work from our lab has documented ASCT2 as the major glutamine transporter in human HCC cells, little is known regarding differences in the array of transporters that operate in primary and metastatic HCC. To address this issue, fourteen human HCC cell lines (7 epithelial and 7 mesenchymal) were evaluated for glutamine transporter expression via reverse‐transcriptase – quantitative polymerase chain reaction (RT‐qPCR) and functional glutamine uptake analyses. The transporters screened via RT‐qPCR were: ASCT2 and LAT1, and six members of the SLC38 glutamine transporter family (System N and A transporters (SNATs)), including SNAT3 and SNAT5 – the dominant System N glutamine transporters in normal hepatocytes. All cell lines universally expressed ASCT2 and LAT1 as well as the SLC38 transporters SNAT2 and SNAT7. The System N transporters SNAT3 and SNAT5 were differentially expressed in some epithelial HCC, while the System A transporters SNAT1 and SNAT4 were variably expressed in both HCC cell types. Functional analysis revealed that the majority of glutamine in all HCC cell lines was transported by a mechanism consistent with ASCT2, independent of transporter mRNA expression signatures. Importantly, ASCT2 and LAT1 transporter activities and cognate mRNA and protein expression levels were discordant, highlighting the complex and layered regulation between gene expression and physiological activity. The results also support continued focus on ASCT2 and LAT1 as a primary therapeutic targets for both primary and metastatic HCC. Support: NIH Grant# R15CA108519 (BPB)
Human milk exosomes resist digestion in vitro and are internalized by human intestinal cells
Authors: Lonnerdal Bo , Du Xiaogu , Liao Yalin , Li Jie
Published: June 2021

Human milk contains exosomes, i.e. microparticles consisting of microRNAs (miRs) with sizes of ~22 nts. Exosome‐mediated transfer of miRs is a novel mechanism of genetic exchange between cells. miRs bind to the 3′‐untranslated region of target mRNAs and cause translational block or mRNA degradation. We hypothesized that milk exosomes can resist digestion in the gastrointestinal tract and be taken up by enterocytes and thus have the potential to regulate gene expression. Human milk samples from donors at different stages of lactation were collected into tubes with RNAse inhibitor. Exosome RNA isolated by ExoQuick‐TC was eluted in RNAse‐free Exosome lysis buffer. CD9 was used as positive control and calnexin as negative control. miRs of 22 nts extracted from isolated exosomes were verified by BioAnalyzer. Sequencing was done using Illumina HiSeq 2500. miRDeep2 was used to find miRNA signatures from the read alignments to known miR sequences (miRBase) and to quantify expression. Several miRs involved in the immune system, e.g. miR‐146, miR‐181, miR‐21, miR‐16 and let‐7 were found. Only a few miRs were differentially expressed during lactation. In vitro digestion (pepsin + pancreatin) under conditions mimicking those in infants showed a significant proportion of the exosomes surviving digestion as verified by TEM. Human intestinal epithelial cells were incubated with digested exosomes and intracellular localization was determined by anti‐CD9 antibodies using confocal microscopy. The exosomes localized to the nucleus as visualized by Topro3. Thus, human milk exosomes are capable of surviving digestion and being taken up by enterocytes where they localize to the nucleus and may affect gene expression. (Supported by Mead Johnson Nutrition)
Vitamin D (VD) prevents oxidative stress via regulating NOX4/Nrf2/Trx signaling cascade and upregulates SIRT1‐mediated AMPK/IRS1/GLUT4 pathway and glucose uptake in high glucose treated 3T3L1 adipocytes
Authors: Manna Prasenjit , Jain Sushil
Published: June 2021

This study examined the hypothesis that VD regulates cellular redox signaling cascade and upregulates insulin signaling in diabetes. 3T3L1 adipocytes were treated with VD (1,25(OH)2D3, 0‐50 nM, 2 h) and high glucose (HG, 25mM, 20 h). Results (n=3) showed that VD supplementation decreased ROS production (31%), NOX4 protein expression (71%), and NF‐κB phosphorylation, and increased the protein expression of Nrf2 (78%) and Trx (30%) in HG‐treated cells. VD also upregulated SIRT1 protein expression and AMPK phosphorylation and stimulated the IRS1/PI3K/PIP3/PKCζ/λ signaling cascade, GLUT4 translocation (44%), and glucose uptake (34%) in HG‐treated cells. The effect of VD on AMPK/IRS1/GLUT4 signaling pathway was significantly inhibited in SIRT1 knockdown cells. In VD‐receptor knockdown cells the effect of VD on redox signaling cascade, SIRT1/AMPK/GLUT4 pathway, and glucose uptake was also inhibited against HG exposure, suggesting a receptor mediated role for VD in maintaining cellular redox equilibria and glucose homeostasis in HG‐treated cells. This study demonstrates a novel molecular mechanism by which VD prevents oxidative stress via modulating NOX4/Nrf2/Trx redox signaling and upregulates SIRT1‐mediated AMPK/IRS1/GLUT4 pathway and glucose uptake in HG‐treated adipocytes. (Supported by NIH RO1 AT007442 and Malcolm Feist Chair in Diabetes)
Are Spot Test Multiple Choice Questions Easier to Answer than Short Answer Questions?
Authors: Wilkinson Tracey , Shaw Hannah
Published: June 2021

Machine marked multiple choice assessments are often preferred over those requiring manual marking, with most medical schools and boards using multiple choice questions (MCQs), usually single best answer, as the main format for written tests. While these often give excellent reliability and validity, disadvantages are that students can guess the answers with no penalty, or can rely on recognition rather than having to produce information. In order to investigate whether this makes tests easier for students, 277 first year medical students were randomly allocated into two groups (A and B). Both groups wrote a formative spot test, delivered by PowerPoint. The questions were largely anatomical, but with a few other basic science questions included. The test was composed of both MCQ and short answer question (SAQ) format questions. Each group answered 40 questions in total, with 20 of each type, but the 20 questions that Group A answered in MCQ format were given to Group B as SAQs and vice versa. A Student t test was carried out to determine if there was a difference between the mean scores achieved for the two types of questions in each format. The mean SAQ score (with no half marks awarded) was 34.3% (±14.8), while that for the MCQs was 54.7% (±15.6). If half marks were included in the scores attained for the SAQs, the mean score was 37.0% (±14.9). There was a statistically significant difference (p<0.01) between the SAQ and MCQ scores, regardless of whether half marks were included. It is therefore suggested that MCQs alone should not be relied upon, at least for spot tests, as scores achieved with MCQs are significantly higher than for SAQs. Free written response type questions should also be included.
Serum Citrulline does not Predict Stunting or Environmental Enteric Dysfunction in Tanzanian and Malawian Infants
Authors: Gosselin Kerri , McDonald Christine , Kellogg Mark , Manji Karim , Kisenge Rodrick , Aboud Said , Maleta Ken , Benzoni Nicole , Fawzi Wafaie , Manary Mark , Duggan Christopher
Published: June 2021

Background

Serum citrulline (CIT) is a marker of gastrointestinal mucosal mass and function. Environmental enteric dysfunction (EED) is associated with suboptimal child growth, but robust biomarkers for EED are lacking. We sought to determine if CIT at age 6 weeks predicts stunting (height‐for‐age Z‐score < ‐2) at 18 months, and if CIT correlates with lactulose to mannitol (L:M) ratio, a measure of EED.

Methods

In 413 non‐stunted infants from Tanzania, blood was obtained at age 6 weeks, and anthropometrics measured monthly for 18 months. In 102 Malawian children between age 1‐3 years, dual‐sugar absorption tests were performed. CIT was analyzed in both studies by quadrupole mass spectrometer.

Results

In Tanzanian infants, mean (SD) CIT at 6 weeks was 18.0 (5.8) µmol/L. Compared to infants with CIT in the lowest quartile, the Hazard Ratio of time to first stunting for the highest quartile was 1.07 (95%CI: 0.64, 1.78). In Malawian children, mean (SD) CIT in stunted children was 18.2 (9.8) vs. 19.4 (9.5) in non‐stunted children (p=0.60). There was no association between L:M and CIT (r=‐0.04, p=0.65) or height‐for‐age Z‐score and CIT (r=‐0.10, p=0.31).

Conclusion

CIT did not predict subsequent stunting in Tanzania or correlate with markers of EED in Malawi. Biomarkers for adverse nutritional outcomes in children are needed.

Funding NICHD (R01 HD048969; K24HD058795), Bill and Melinda Gates Foundation (OPP1066203)
Two Functions of Lysyl Oxidases: Extracellular Matrix Maturation and Cell Proliferation
Authors: Trackman Philip , Saxena Debashree , Bais Manish
Published: June 2021

Lysyl oxidases are enzymes which catalyze the final enzymatic modification of ε‐ amino groups of lysine residues of elastin, and lysine and hydroxylysine residues of collagens, to form peptidyl‐aldehydes required for biosynthetic cross‐linking and extracellular matrix maturation and function. This family includes lysyl oxidase (LOX) and lysyl oxidase‐like 1 – 4 (LOXL1 – LOXL4). CCN2 contributes to fibrosis development in gingival overgrowth caused by the anti‐seizure drug phenytoin, though the mechanism CCN2 is unclear. Here we investigate the hypothesis that CCN2 could up‐regulate LOXL2 to promote gingival fibroblast insoluble collagen deposition.

CCN2 up‐regulated LOXL2 protein levels in primary human gingival fibroblast cultures. shRNA‐mediated knockdown of LOXL2 blocked collagen accumulation in CCN2‐treated and non‐treated primary human gingival fibroblast cultures determined by Sirius Red staining. DNA in cell layers was also strongly diminished in cell layers. Cell proliferation was decreased in LOXL2 shRNA transduced cells, while apoptosis was not affected. Active LOXL2 enzyme addition promoted both increased proliferation and cell layer collagen accumulation.

LOXL2 has two important functions in the development of gingival fibrosis: its known role in promoting collagen maturation, and the new role of promoting cell proliferation. The mechanism of promotion of proliferation of gingival fibroblasts by LOXL2 is under investigation.

Supported by R01 DE11004.
Thermostable Alkaline Protease Production by Bacillus Aryabhattai J4
Authors: Selim Samy
Published: June 2021

The current study reports the production and biochemical characterization of a thermostable alkaline protease from Bacillus aryabhattai J4, isolated from Al jouf region, KSA. The enzyme was concentrated by spinning through a centriplus, centrifugal ultrafiltration Millipore membrane with a total yield of 15%. The relative molecular mass of this protease determined by SDS‐PAGE was ranging from 40‐60 KDa. The extracellular protease of B. aryabhattai J4 was dependent on high salt concentrations for activity and stability, and it had an optimum temperature of 60oC in the presence of 2.5 M NaCl. This enzyme was stable in a broad pH range (6‐10) with an optimum pH of 9 for azocasein hydrolysis. This extracellular protease therefore could be defined as thermostable and alkaliphilic with distinct properties that make the enzyme applicable for different industrial purposes.
Using Participatory Community Workshops to Develop Salient Communications Strategies for Introducing a Small‐Quantity LNS in Rural Malawi and Mozambique
Authors: Kodish Stephen , Aburto Nancy , Dibari Filippo , Mlambo Trust , Gittelsohn Joel
Published: June 2021

Study Objective

We sought to identify barriers and preferred behavior change communication (BCC) strategies for introducing a 20‐gram lipid‐based nutrient supplement (LNS) for children 6 – 23 months

Methods

The formative research had 3 iterative phases, including participatory community workshops (CW) among male and female participants over 8 weeks in each setting. In Malawi, 8 CW were conducted with a total of 136 people. In Mozambique, 13 CW were carried out among Macua (n = 6) and Mwani (n = 7) participant groups with a total of 228 people. Each CW included 13 ‐ 23 participants (mean = 17.2) and served as a forum for brainstorming and voting for BCC strategies. Simple frequencies were tallied for analysis.

Results

In Malawi, community members put the onus on female caregivers to ensure LNS would be used appropriately and preferred to receive messages about LNS through community groups (Care Groups) and health workers. In Mozambique, Macua community members preferred personal forms of BCC whereas Mwani participants preferred less personal means. While both cultural groups agreed that village chiefs, activistas, and traditional healers should be central to BCC efforts, Macua communities preferred interpersonal channels such as “associations of caregivers” but Mwani community members voted for radios and megaphones as preferred channels.

Conclusion

Using participatory CW in a bottom‐up approach to intervention development may enhance likelihood of community engagement and ownership, and contribute to successful nutrition outcomes among vulnerable populations.

Funded by Children's Investment Fund Foundation
Effects of soybean pectin on blood glucose and insulin responses in healthy men
Authors: Jones Melissa , Gu Xuan , Stebbins Nathan , Crandall Philip , Ricke Steven , Lee Sun‐Ok
Published: June 2021

Pectin is a soluble fiber with demonstrated health benefits such as the ability to lower blood glucose and cholesterol, increased satiety leading to lower caloric intake and improved insulin resistance. These benefits suggest that pectin may help in prevention and treatment of diseases such as diabetes and obesity. Soybean seed coats, a co‐product of soybean processing, are good source of fiber (pectin) and shows potential as a value‐added product. The objective of this study is to examine the effects of soy pectin on blood glucose and insulin responses. Using a randomized‐crossover design, fifteen healthy men were randomly assigned to two groups (control and soy pectin). Fasting finger‐stick blood samples were collected at 15 minutes before and 0, 15, 30, 45, 60, 75, 90, 120, and 180 minutes after consumption of control solution with added soy pectin or a control solution. Although no specific time interval was significantly different, a reduction in plasma glucose and insulin concentrations was observed. Compared with the control, mean glucose iAUC (incremental area under the curve) for the soy pectin treatment was lowered by ~13.2% from 5059 + 506 to 4390 + 387 µU (~3 h) L‐1. Results suggest soy pectin has a potential for use as a functional food ingredient to improve human health. Funding provided by Arkansas Soybean Promotion Board is greatly appreciated.
Cardiac Vagal Afferent Response in Rats during Cardiac Contractility Modulation (CCM)
Authors: Sengupta Jyoti , Kannampalli Pradeep , Belligoli Alberto , Rousso Benny , Ben‐Haim Shlomo , Gutterman David
Published: June 2021

Congestive heart failure (CHF) is responsible for substantial cardiac morbidity and mortality. Cardiac Contractility Modulation (CCM) delivers non‐excitatory endocardial electrical pulses during the refractory period. CCM enhances cardiac contractility, ejection fraction, and quality of life in patients. The underlying mechanism of action for these benefits is not fully understood. Since similar impulses delivered to the gut increase muscle contraction leading to activation of vagal afferents, we tested the effect of CCM on vagal afferent activity in the heart.

Hypothesis

CCM results in an increase in activity of cardiac vagal afferent nerves. Since CCM is non‐excitatory, we speculate that CCM reflexly activates vagal afferents via increases in contractility, reducing excessive efferent sympathetic tone in CHF.

Methods

Adult male Sprague‐Dawley rats under pentobarbital anesthesia were instrumented for extracellular recordings of cardiac vagal afferent firing during CCM stimulation of the left ventricle (4V or 7.5V for 60s).

Results

In 18 vagal nerve fibers with cardiac receptive fields, CCM produced an intensity dependent increase (p<0.05) in firing frequency of 10 fibers (4.2 ± 1.2 Hz at 7.5V vs. 1.4 ± 0.66 Hz at baseline). 6 neurons were not affected by CCM. In two neurons, 4V stimulation increased while 7.5V had no effect on single fiber firing.

Conclusion

CCM, a new therapy for CHF elicits activation of cardiac vagal afferents. This likely results from a reflex increase in regional contractility, contributing to the clinical benefit of CCM via an increase in vagal afferent and reduced sympathetic tone. Supported by Impulse Dynamics, Inc.
Novel Behavioral Assays to Model Neurodevelopmental Disorders in the Xenopus laevis Tadpole
Authors: Ramirez‐Vizcarrondo Carolina , Hasan Mashfiq , Gu Jenny , Khakhalin Arseny , Aizenman Carlos
Published: June 2021

Experimental behavioral assays and animal models are essential to elucidate the mechanisms that underlie behavioral phenotypes associated with disorders such as Autism Spectrum Disorders and Fragile X Syndrome. The Xenopus laevis tadpole has long been used as a model to study the mechanisms that underlie development of brain circuits. We aim to use this organism as a model for understanding the etiology of neurodevelopmental disorders. Their simplified nervous system and well‐characterized stages of development are some advantages that make Xenopus an efficient organism to model these disorders. In this study, we develop and validate a comprehensive suite of behavioral experiments to assess normal and abnormal neurodevelopment in Xenopus tadpoles. Behavioral assays include visual avoidance behavior (a type of behavior in which the animal avoids objects engaging at a collision trajectory), acoustic startle reflex habituation (a form of non‐associative memory that relies on hindbrain circuitry), pre‐pulse inhibition (a type of hindbrain‐mediated short‐term sensory processing in which a weaker pre‐stimulus inhibits the effects of a subsequent strong stimulus), propensity to seizures, and schooling behavior. We show that Xenopus tadpoles express several innate behaviors that can be manipulated and used to infer normal and abnormal neural circuit development. In combination with existing electrophysiological and neuroanatomical assays, this study will help to firmly establish the Xenopus tadpole as a useful model for studying basic biological mechanisms underlying neurodevelopmental disorders.

Funding Sources: APS IOSP Fellowship (NSF IOS‐1238831), NEI (NIH), and Brown University
High vs. Low Responders to Exercise: Role of Epigenetic Modifications in Altering PGC1α Gene Expression and Intramyocellular Lipid Content in Skeletal Muscle
Authors: Taylor Erin , Covington Jeffrey , Galgani Jose , Ravussin Eric , Bajpeyi Sudip , Henagan Tara
Published: June 2021

Interindividual responses to exercise training exist in PGC1α gene expression and may be due to plasticity of epigenetic modifications. Here, we determined if exercise‐induced variation in PGC1α DNA methylation was associated with interindividual responses in ‐1N position, gene expression and intramyocellular lipid (IMCL) content. Sedentary, lean men (n=15, aged 24±1 yrs, BMI 23.8±0.4) underwent an acute bout of exercise (50% VO2max, ~650 kcal). Muscle biopsies were taken before and immediately after exercise. PGC1α DNA methylation of the regulatory ‐260 nucleotide (nt) and ‐1N position were determined in duplicate via pyrosequencing and scanning PCR, respectively. PGC1α expression was measured by qRT‐PCR and IMCL via BODIPY staining. Subjects were divided into high (change in DNA methylation percentage 蠄 0; N=7) or low (change in DNA methylation percentage > 0; N=8) responders. High but not low responders exhibited repositioning of the ‐1N away from the ‐260nt, showed a significant increase in PGC1α expression (P = 0.03) and tended to have decreased IMCL content (P = 0.17). Exercise–induced DNA hypomethylation at the PGC1α ‐260nt and repositioning of the ‐1N upstream of the regulatory ‐260nt are linked to increased gene expression and possibly decreased IMCL content. Epigenetic regulation of PGC1α may contribute to interindividual responsiveness to exercise training.
A step by step visual guide to using the Sectra Visualization Table for 1st and 2nd year medical students
Authors: Barrack Daniel , Horn David , Benninger Brion
Published: June 2021

INTRODUCTION

The Sectra Visualization Table (SVT) is a computer that allows a user to view CT and MRI imaging rendered in 3D, which can be rendered in a tissue specific manner and manipulated using a touch screen for educational and clinical purposes. SVT is an extremely useful medium, but unclear how long it takes for a novice operator to become proficient. The objective of this study was to develop a training document which includes strong visual cues for efficient processing of the SVT's use while addressing andragogical methods.

METHODS

Literature search was conducted regarding SVT and 1st year medical student (MS) curriculum. 60 MS were given 15 minutes to read the guide composed of illustrations with minimal text. Guide included step by step demonstrations of tools, used to manipulate the CT/MRI image. Subsequently, they were allowed to manipulate images with the touch screen. Their proficiency of manipulating 3‐D images was assessed. Likert Scale questionnaire was administered post test.

RESULTS

No obvious studies were identified regarding the use of SVT with MS. MS successfully interpreted the guide, and used the tools associated with manipulating images. The Likert Scale scores were positive regarding aiding the MS in understanding stereostructural anatomy.

DISCUSSION

Following an anatomy dissection or didactic course, having access to manipulate 3‐D CT/MRI images would enhance MS’ understanding of stereostructural anatomy. MS will be exposed to their patients' imaging anatomy. SVT guide proved to be a shallow learning curve for students rotate and magnify an actual CT/MRI on a 46 inch touch screen.

CONCLUSION

This study revealed that a visual heavy teaching guide can enable MS to manipulate 3D CT/MRI images with minimal training.
Cartilage or Bone? Collagens in “Cartilaginous” Fish Skeletons Answer an Old Question
Authors: Blumer Michael , Seidel Ronald , Pechriggl Elisabeth‐Judith , Lyons Kady , Dean Mason
Published: June 2021

The skeletons of cartilaginous fishes (sharks and rays) comprise an inner core of uncalcified cartilage, an outer fibrous perichondrium, and a layer of mineralized tiles (tesserae) between them. As mammalian perichondrium and cartilage are patterned on different collagens (Coll1 and Coll2, respectively), it has been debated whether tesserae are more like bone (Coll 1‐based) or mineralized cartilage. Using an array of histology techniques we show that stingray tesserae are bipartite, having an upper, mineralized perichondrium “cap zone” (Coll1) that merges into a lower, mineralized cartilage “body zone” (Coll2), with the two collagens interspersed at the zones' interface. Waves of varying mineral density observed in tesserae, believed to be records of growth processes, are mirrored in periodic density variation of the collagen matrix. Collagen fiber bundles extend uninterrupted between unmineralized and mineralized areas (e.g. from perichondrium into the cap zone or through joint spaces between tesserae). The upper (perichondral) portions of joints contain both Coll1 and Coll2, yet lower (chondral) portions contain finer, unidentified fibers that stain neither for Coll1, Coll2, nor elastin. Unlike mammalian growth plate cartilage, mineralization fronts (tesseral edges) were not associated with hypertrophic cells or Coll10 expression, although Coll10 staining was observed in a thin layer of cartilage matrix (Coll2) sometimes seen between tesserae and perichondrium. Our results show that tesserae exhibit an amalgam of features of bone and mineralized cartilage, and indicate that cartilage mineralization can occur without Coll10 expression, cell hypertrophy or cell death.
A Study of The 2001 Anthrax Terror Attacks and the History of Biological Warfare
Authors: More Roland
Published: June 2021

In the following abstract we will review the history, data and some first person accounts of the 2001 Anthrax attacks in the United States. We will also review the history of biological warfare and discuss accidental releases of anthrax spores in the former Soviet Union during the closing days of the cold war. We will also analyze in‐depth the extent of the former Soviet Union Bioweapons program and the USSR's response to the United States‐ Strategic Defense Initiative (SDI) or Stars Wars program. The USSR's response was code named the “ Death Star “ program.

Epidemiologic investigation indicated that the outbreak, in the District of Columbia, Florida, New Jersey, and New York, resulted from intentional delivery of B. anthracis spores through mailed letters or packages. We describe the clinical presentation and course of these cases of bioterrorism‐related inhalational anthrax.

In 1979, in Sverdlovsk, former Soviet Union, an apparent aerosol release of B. anthracis spores from a military facility resulted in the largest outbreak of inhalational anthrax in the 20th century .

Before October 2001, the last case of inhalational anthrax in the United States had occurred in 1976. Identification of inhalational anthrax in a journalist in Florida on October 4, 2001, marked the beginning of the first confirmed outbreak associated with intentional anthrax release in the United States. We describe the clinical presentation of the first 10 cases of this bioterrorism‐related outbreak. Also in this investigation will be the data compiled by the Centers for Disease Control as well as archival data form the Soviet Anthrax accident in Sverdlovsk 1979.

Reference sources omitted due to limited submission space .
Simple Liking Survey Associates with Weight Loss Success in a Worksite Intervention
Authors: Sharafi Mastaneh , Faghri Pouran , Huedo‐Medina Tania , Duffy Valerie
Published: June 2021

Objective

To assess the utility of diet and physical activity surveys to evaluate a worksite weight loss intervention.

Method

Participating in a tailored education program were 58 females with elevated risk of type II diabetes from 4 long‐term care facilities. Diet and physical activity were measured by liking and frequency surveys at baseline and post‐intervention (wk 16); adiposity was measured each time and follow‐up (wk 28). A latent variable approach was used to test factor structure of derived diet quality and physical activity scores. Repeated measure analysis of covariance measured change in dietary and physical activity scores; effects on weight loss were measured by ANCOVA and nested regression analysis.

Results

Average weight loss was 3% by wk 16 and 2% by wk 28. Restrained eaters (reporting high liking but low intakes of energy‐dense foods) at baseline achieved greater weight loss. By wk 16, females reported increases in liking for and intakes of healthier foods, yet only liking increases associated with more weight lost. Females who reported increases in both healthy food liking and intake had greater weight loss; those who reported greater intake but not liking (possible misreporting) gained weight by wk 16. Physical activity liking and frequency scores had parallel increases with the intervention yet were not predictive of weight loss by wk 16 or 28.

Conclusion

Surveying food and physical activity likes/dislikes is a simple and feasible approach to evaluate behaviors in a worksite intervention. Improvements in liking for healthy foods best associated with weight loss success. Examining food liking versus intake may identify behaviors that associate with (dietary restraint) or against (misreporting) intervention success.

Funding Source: USDA Hatch grant
Influence of exercise training on markers of tumor microenvironment in breast cancer: a comprehensive meta‐analysis from 15 trials
Authors: Ramirez Velez Robinson , Meneses‐Echávez José , González Jímenez Emilio , Río‐Valle Jacqueline , Correa‐Bautista Jorge
Published: June 2021

Objective

To establish the influence of exercise interventions on tumor microenvironment‐related markers, including inflammatory cytokines, C‐reactive protein (CRP) and Insulin‐like growth factors (IGF's) in breast cancer survivors.

Methods

PRISMA statement was followed. MEDLINE, Ovid, EMBASE and CENTRAL were searched for randomized controlled trials until February 2014. Heterogeneity was measured by using the I2 statistics. A random‐effects models was used in presence of high statistical heterogeneity (I2>50%). Meta‐regression analyses were also conducted.

Results

Data from 15 studies were pooled (n=1,447; mean age= 51.6 years old). Exercise interventions resulted in positive effects for CRP, IL‐2, IL‐10, IGF‐I, IGF‐II and IGFBP‐3 (p<.05). Non‐significant differences were found for IL‐6 and TNF‐α. Meta‐regression models showed that duration (>40 minutes/session) and training intensity (>70% maximum heart rate) of the exercise were predictors of the effects on tumor markers (p<.05)

image

Conclusions

Exercise training exerts favorable effects on tumor microenvironment in breast cancer survivors by improving systemic pro‐inflammatory profile and the serum concentrations of growth markers linked to tumorigenesis. The reductions found for IL‐10 suggest an immunostimulating role of exercise in women with breast cancer.