bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rho‐kinase mediated vasoconstriction is upregulated in aged skin
Authors: Lang James A , Jennings John D , Holowatz Lacy A , Kenney W Larry 
Published: June 2021

Primary human aging is associated with augmented pro‐constrictor vascular signaling mechanisms, which may be mediated by activation of Rho‐kinase (ROCK). We hypothesized that the contribution of ROCK to vasoconstriction (VC) is greater in aged skin. Cutaneous VC was elicited by 1) whole‐body cooling (Tsk=30.5oC) and 2) local norepinephrine (NE) infusion (10−6M). Four microdialysis fibers were placed in the forearm skin of 8 young (Y) and 8 older (O) subjects for infusion of 1) Ringers solution (control), 2) 3mM fasudil (ROCK inhibition), 3) 20mM L‐NAME, and 4) both ROCK + NOS inhibitors. Red blood cell flux (LDF) was measured by laser Doppler flowmetry over each site. Cutaneous vascular conductance was calculated (CVC = LDF/MAP) and normalized to baseline CVC (%ΔCVCbase). VC was lower at the control site in O during cooling (Y: ‐34 ± 3, O: ‐23 ± 4 %ΔCVCbase; P<0.05) and NE infusion (Y: ‐52 ± 5, O: ‐39 ± 9 %ΔCVCbase; P<0.05). Fasudil infusion attenuated VC in O but not Y during both cooling (Y: ‐29 ± 5, O: ‐8 ± 1 %ΔCVCbase; P<0.01) and NE (Y: ‐22 ± 4, O: ‐8 ± 4 %ΔCVCbase; P<0.01) suggesting that ROCK mediated 15% and 53% of the total reflex VC response in Y and O, respectively. NOS inhibition did not alter ROCK‐mediated VC (P<0.05). ROCK inhibition significantly attenuated cutaneous VC in aged but not young skin suggesting that downstream vascular mechanisms of VC differ with age, and ROCK is upregulated in aged skin.Supported by NIH RO1‐AG‐07004‐18
The influence of age on carotid baroreflex mediated vasoconstriction in humans
Authors: Fisher James P , Young Colin N , Vianna Lauro C , Kim Areum , Deo Shekhar , Fadel Paul J 
Published: June 2021

The carotid baroreflex (CBR) plays a critical role in the beat‐to‐beat regulation of arterial blood pressure (BP) primarily via reflex modulation of sympathetic nerve activity and vascular conductance. Decreased sensitivity of peripheral alpha‐adrenergic receptors has been reported in healthy older subjects however, it is unclear whether this may influence the CBR regulation of BP. To begin to address this question, mean BP, leg vascular conductance (LVC) and heart rate (HR) responses to simulated CBR hypotension were characterized in five young (22±2yr) and six older middle‐aged (63±2yr) healthy subjects using 5s pulses of neck pressure (NP, +40 Torr). Mean BP responses to NP tended to be reduced in older (+4±2 mmHg) compared to younger subjects (+9±3 mmHg), although this apparent difference did not reach statistical significance (P=0.209). Interestingly, the LVC responses to hypotension were similar in both groups (‐25±5% vs. ‐23±8%, older vs. younger, respectively; P=0.900). In contrast, HR responses were significantly attenuated in the older (+2±1 bpm) compared with the younger group (+10±3 bpm, P=0.039). In summary, these preliminary data suggest that the ability of the CBR to regulate BP in response to a hypotensive challenge appears to be attenuated in older individuals; however, alterations in sympathetically‐mediated leg vasoconstriction do not appear to contribute.Supported by R01‐HL093167.
Distribution of stanniocalcin‐1 (STC‐1) binding sites within the rat brainstem and cerebellum
Authors: Moreau Jason M. , Wagner Graham F. , Ciriello John 
Published: June 2021

STC‐1 is a glycoprotein hormone that regulates calcium/phosphate homeostasis. STC‐1 has been shown within mammalian brainstem and cerebellum cells. However, whether these cells exhibit STC‐1 receptors is unknown. Thus, the distribution of STC‐1 binding sites (STC‐R) was investigated by in situ ligand binding using a STC‐1‐alkaline phosphatase fusion protein within the brainstem and cerebellum of the rat. Brains were fixed in 4% paraformaldehyde, paraffin embedded and serial, transverse sections were cut (6 μm) and processed for STC‐R. In the cerebellum, Purkinje neurons and neurons within the molecular layer of the cerebellar cortex and medial cerebellar n. exhibited STC‐R. In the brainstem, neurons exhibiting STC‐R were seen in the central grey, raphe n. (dorsal and pallidus), inferior colliculus, ventral n. of the lateral lemniscus, superior olive, lateral parabrachial n., locus coeruleus, dorsal tegmental n., parapyramidal area, external cuneate n., inferior olivary n. (medial and principal), area postrema, n. tractus solitarius, and lateral reticular n. Additionally, cells of the choroid plexus and ependymal cells lining the central canal were also labelled. These data suggest that STC‐1 may alter the function of these structures by regulating neuronal calcium/phosphate transport.Supported by HSFO and CIHR
Inhibition of the IP‐receptor does not improve the cardiovascular changes in murine model of endotoxemia
Authors: Staehr Mette , Jensen Boye L , Hansen Pernille B 
Published: June 2021

Selective inhibition of cyclooxygenase 2 (COX‐2) results in reduced systemic prostacyclin (PGI2) production. The levels of COX‐2 and PGI2 are increased in endotoxemia, and we therefore hypothesized that PGI2 plays an important role in the cardiovascular failure observed during sepsis.Chronic indwelling catheters were placed in femoral artery and vein in mice and the effect of the PGI2‐receptor (IP) antagonist BR5064 (Bayer, 0.1 mg/kg) and the PGI2 analogue, Beraprost (1 μg/kg) on blood pressure was tested. Injection of Beraprost induced a significant fall in blood pressure from 103 to 77 mmHg with no effect on heart rate. BR5064 did not change resting blood pressure and heart rate, but blocked the effect of Beraprost. Next, an LPS bolus (2 mg/kg) was given which led to a significantly reduced blood pressure and heart rate (106±7 to 75±2 mmHg and 627±53 to 306±33 bpm, respectively) 8 hours after injection (n=11).Pre‐treatment with BR5064 before LPS, did not improve the cardiovascular changes: 104±3 to 78±2 mmHg and 654±9 to 429±57 bpm respectively (n=10).We therefore conclude that while the IP‐antagonist specifically inhibits the IP‐receptor, it does not prevent the acute deterioration of cardiovascular function in a model of endotoxemia which suggest that prostacyclin signaling is less important for the observed cardiovascular impairment.Support: the Danish medical research council and Novo Nordisk foundation.
Involvement of the actin and tubulin networks in the trafficking of V‐ATPase, NBCe1‐A and NBCe1‐B in a submandibular duct cell line
Authors: Oehlke Oliver , Martin Henno , Roussa Eleni 
Published: June 2021

Cytoskeletal components are established players in protein trafficking in epithelial cells. The bicarbonate‐secreting epithelium of salivary ducts is equipped with several acid‐base transporters whose cellular distribution is altered after systemic acid‐base disturbances. Here we investigated the role of actin and tubulin in V‐ATPase and electrogenic NBC1 distribution under physiological and pathological conditions in vitro. Therefore, extracellular acidosis or alkalosis was induced in the presence or absence of cytochalasin D or colchicine.Disruption of the actin network differentially influenced constitutive trafficking and adaptive redistribution after acid‐base disturbances. Following cytochalasin D treatment all transporters failed to reach the membrane. Trafficking of NBCe1‐B is impaired after disruption of the tubulin network as well, whereas localisation of NBCe1‐A was not affected by colchicine treatment during acid‐base disturbances.The results indicate differential regulation of tubulin‐mediated trafficking for NBCe1‐A and ‐B, reflecting their differences in the direction of ion transport and localisation in a polarized epithelium in vivo.This work was supported by the DFG.
Functional Studies of Acid Transporter in Cultured Rat Epididymal Cell
Authors: Zuo Wulin , Shan Jiajie , Li Sheng , Wong Patrick Y. D. , Zhou Wenliang 
Published: June 2021

The epididymis is the site for the maturation and storage of spermatozoa. The acidic epididymal fluid, which maintains spermatozoa in a quiescent state, contributes to this process. Several transporters, including Na? exchanger (NHE) and vacuolar H+ATPase(H+ATPase), are believed to be involved in the pH regulation of epithelial fluid. In the present study, double immunofluorescense of H+ATPase and carbonic anhydrase II (CA II) in primary culture of cauda epithelial cells showed that the system was a suitable model for investigation of acid secretion by clear cells. Clear cells were pharmacologically distinguished from principal cells in acid/base transportation. The H+ATPase inhibitor, bafilomycin A1, and NHE inhibitor, amiloride, suppressed the pHi recovery by 85% and 54%, respectively. It suggested that, in addition to NHE, clear cells actively pump proton from cytoplasm into extracellular space via H+ATPase. Luminal fluid was acidified by H+ATPase, and this process could be inhibited by its inhibitors with IC50 values of 12 nM. Rat cauda sperm motility was demonstrated to be regulated by the acid fluid. The present work shows that the minority cell type‐clear cells play an important role in the pH regulation of epididymal fluid via H+ATPase.This work was supported by Hong Kong RGC grant (No.452506) and the National Natural Science Foundation of China (No.30770817)
Topology Determination of the Transmembrane Domain of the Electrogenic Sodium Bicarbonate Cotransporter NBCe1‐A
Authors: Zhu Quansheng , Kao Liyo , Liu Weixin , Newman Debra , Kurtz Ira 
Published: June 2021

NBCe1‐A electrogenically cotransports sodium and bicarbonate across the basolateral membrane of proximal tubule cells. The illusive transport mechanism of NBCe1‐A requires structural analysis of the transport protein. NBCe1 has been proposed to traverse the lipid bilayer at least 10 times based on in vitro glycosylation assay. To further determine the topology of NBCe1‐A in vivo, we performed cysteine scanning mutagenesis coupled with sulfhydryl specific chemistry. Fifty six cysteine residues were individually introduced throughout a modified NBCe1‐A protein with five cytoplasmic endogenous cysteines mutated to serine. Location of introduced cysteine residues were determined by whole cell labeling with two cysteine specific reagents: membrane permeant biotin maleimide (BM) and membrane impermeant MTS‐TAMRA. An introduced cysteine labeled with BM indicates its surface location, whereas lack of labeling indicates the residue resides in the lipid bilayer or in a BM inaccessible conformation. Introduced cysteines labeled with MTS‐TAMRA indicate they are exclusively located on the extracellular surface of the protein. Residues D449, A450, T451 and D452 in proposed extracellular loop 1, N503 in loop 2, E714, T718 and R722 in loop 4 were labeled both by BM and MTS‐TAMRA, demonstrating the first half of the transmembrane domain contains 8 transmembrane segments, highly homologous to AE1. The majority of introduced cysteines in the remaining transmembrane domain were not labeled by BM, suggesting that folding of this region is highly compacted unlike AE1. Based on these results, we propose a new topology model for the transmembrane domain of NBCe1‐A.Supported by NIH
Estrogen enhances IkBα synthesis and inhibits NF‐kB p65 binding to the promoters of inflammatory genes in rat aortic smooth muscle cells
Authors: XING DONGQI , Nozell Susan , Chen Yiu‐Fai , Feng Wenguang , Oparil Suzanne 
Published: June 2021

BackgroundThe NFκB signaling pathway is critical for the expression of a variety of genes involved in the response to vascular injury. Estrogen (17β‐estradiol, E2) inhibits expression of these genes in an estrogen receptor‐dependent manner in balloon injured rat carotid arteries and in tumor necrosis factor (TNF)‐α treated rat aortic smooth muscle cells (RASMCs) in vitro. This study tested the hypothesis that E2 inhibits NFκB signaling and defined the machanisms.MethodsIκBα expression was determined using real time RT‐PCR and Western blot analysis. Interactions between NFκB p65 and promoters of inflammatory mediators were evaluated by chromatin immunoprecipitation (ChIP) assay.ResultsRASMCs treated with TNF‐α demonstrated rapid degradation of IκBα (10‐30 min), followed by a dramatic elevation in IκBα mRNA and protein synthesis (40~60 min). E2 enhanced TNF‐α induced IκBα mRNA and protein synthesis without affect IκBα degradation (Figure A~C). ChIP assay confirmed that TNF‐α increased levels of p65 significantly at all promoters analyzed (at 1hr) and these effects were reduced by E2 (Figure D).ConclusionsE2‐inhibited expression of inflammatory mediators in the setting of acute vascular injury may be mediated, in part, by accelerating IκBα re‐synthesis and inhibiting NFκB p65 binding to promoters of target genes.
Anabolic‐Androgenic Steroids Attenuates the Reflex Muscle Vasodilatation
Authors: Alves Maria Janieire N. N. , Santos Marcelo R. , Dias Rodrigo G. , Akiho Cesar A. , Laterza Mateus M. , Rondon Maria Urbana P. B. , Moreau Regina L. M. , Negrao Carlos E. 
Published: June 2021

We hypothesized that anabolic‐androgenic steroids (AAS) would exacerbate symphatetic nerve activity responses and attenuate muscle vasodalation responses during mental stress in young individuals.MethodsNine body builder users and 7 age‐matched body builder nonusers of AAS were studied. AAS was assessed by urine test (chromatography‐mass spectrometry). Mean blood pressure (MBP, oscillometric automatic cuff), forearm blood flow (FBF, plethysmography) and muscle sympathetic nerve activity (MSNA‐microneurography) were evaluated at rest and during mental stress (Stroop Color Word Test).ResultsResting MSNA was significantly higher (28±3 vs. 20±1 bursts/min, P=.03, respectively) and forearm vascular conductance (FVC) significantly lower (2.04±0.19 vs. 2.86±0.31 units, P=.03) in user compared with nonuser of AAS. MBP was not different between groups. FVC responses to mental stress were significantly lower in user compared with nonuser (0.66±0.35 vs. 2.96±0.78 units, P=.01, respectively). MBP and MSNA responses were not different between groups.ConclusionAAS increases MSNA and reduces FBF in healthy young individuals. In addition, the reduction in muscle reflex vasodilatation during mental stress in AAS user is suggestive of impaired endothelial function in these individuals.
A survey of anatomical variation in medical student cadavers: a longitudinal study
Authors: Hovorka Michelle S. , Uray Nandor J. 
Published: June 2021

The goal of our study is to document anatomical variations found in the gross anatomy laboratory setting. This is a long term study to note trends in variations due to changes in human donor populations over the next ten years. In this first year of the study, thirty donated human cadavers are being dissected by medical students. As dissection proceeds, variations and anomalies are photographed and recorded, as are significant pathological findings. As of this time, dissection of the upper limb, back, and thorax have been completed. Anomalies noted include four variations of the brachial plexus including one in which the posterior cord is completely absent; anomalous musculature including an axillopectoral muscle and a sternalis muscle; an azygos lobe of the lung; and five instances of absent cephalic veins. Additionally, significant pathological findings and prosthetic devices are being documented. These findings will serve to form the foundation for a longitudinal study to track trends in the population over time as represented by medical cadavers. Funding is provided by the Kirksville College of Osteopathic Medicine Graduate Program.Grant Funding SourceKirksville College of Osteopathic Medicine Graduate Program
Gross anatomy of a horseshoe kidney: a case report
Authors: Casey Gregory Patrick , Sedlmayr Jayc C. , Oliver Peter , Cork John 
Published: June 2021

At the LSU Health Sciences Center, we discovered a horseshoe kidney in one of the cadavers during laboratory dissection in the nursing gross anatomy course. The donor was an 83 year old male with causes of death related to congestive heart failure, chronic obstructive pulmonary disease, and acute renal failure. Horseshoe kidneys are relatively rare with a reported occurrence of 1 in 400 births worldwide; although this is the first observed in our gross anatomy laboratory. It is a developmental anomaly arising from fusion of the metanephroi around the fifth week of embryonic development. A detailed in situ dissection was done on the cadaver in which major arteries and veins were observed. The horseshoe kidney in this cadaver was supplied by several arterial branches from the abdominal aorta and its bifurcation, and by several venous branches from the inferior vena cava. After initial dissection in situ, the horseshoe kidney, ureters, bladder, most of the abdominal aorta, and most of the inferior vena cava with the common iliac bifurcation were removed for further study and preservation. Although the discovery of this horseshoe kidney is unusual, it is a good example of the type of anatomical variation and medical conditions that makes the cadaver lab an excellent educational environment for nursing school.Grant Funding SourceDepartment of Cell Biology and Anatomy
The Challenge of Identifying Commingled Skeletal Remains via CT Imaging and Morphometric Analysis
Authors: Hong Simon , Delman Bradley N , Maciasz Rachael , Lee Rosanna , Caceres Noel , Sawyer GJ , Marquez Samuel 
Published: June 2021

Human skeletal remains were discovered at a construction site in lower Manhattan. Officially determined that the post‐cranial material was not of medicolegal significance, our team undertook an anatomically driven forensic evaluation of the remains. Post‐cranial isolated bony elements were identified (n = 52), digitally photodocumented, morphometrically assessed and CT scanned for graphical examination. Post‐cranial commingled remains consisted mostly of lower limb bones from at least 3 distinct individuals based on three left cuboid bones found. 31 foot bones were measured and classified using bony landmarks. Comparison to homologous bones of known stature individuals was used to approximate the size differences found among the unknown sample. Maximum a‐p lengths of the three left cuboids measured 44.5, 35.8 and 35.6 mm while the two left calcaneal bones measured 89.2 and 77.5 mm. Size difference was used to group the tarsal bones to either the larger or two smaller individuals. CT imaging of adult femurs revealed their intensity of femoral curvature to fall within the Caucasian spectrum while overall rugosity of the larger bones indicated that the larger individual was male. A combination of CT, comparative and morphometric assessment was the key to overcoming the challenge of cataloging and identifying commingled skeletal remains, and may be the ideal approach for similar future forensic investigations.Grant Funding SourceNone
Paraspinal muscular defects in Lfng segmentation mutant mice
Authors: Smith Heather F , Kusumi Kenro , Rawls Alan , Wilson‐Rawls Jeanne , Fisher Rebecca 
Published: June 2021

Mutations in several regulatory genes along the Notch signaling pathway, including Lfng, are associated with vertebral defects and segmentation disorders. However, the role of these genes in regulating myogenic morphology is unknown. The objective of this study was to assess the role of Lfng in determining the morphology of paraspinal musculature. Nine mice that were homozygous null for Lfng and nine wild‐type specimens were dissected and their paraspinal musculature analyzed. Four Lfng null specimens exhibited variation in the iliocostalis muscle, ranging from unilateral reduction to complete bilateral absence. For multifidus, eight Lfng null specimens exhibited variation, including unilateral and bilateral cranial shifts, caudal and cranial reductions, elongations, and one bilateral absence. A χ2 test revealed a statistically significant difference between the Lfng mutant specimens and wild‐types in the frequency of defects in the iliocostalis and multifidus. These results will be compared to similar findings from Dll3 mutants. The results support the hypothesis that genes in the Notch signaling pathway, Lfng in particular, may influence paraspinal muscular development, although with an incomplete penetrance. These findings have implications for studies of muscular involvement in idiopathic scoliosis and segmentation disorders.This research was partly supported by NIH RO1 AR050687 (KK).Grant Funding SourceUniversity of Arizona
Exploring the anti‐diabetic effect of duodenojejunal bypass: a novel mouse model
Authors: Woods Michael Gregory , Lan Zhu , Wang Jingming , Wang Rennian 
Published: June 2021

Obese patients with Type 2 diabetes who underwent bariatric surgery reverted to normal blood glucose and insulin levels and developed a dramatic increase in insulin sensitivity without continued use of diabetic medication. The mechanisms involved in this reversal are not known although the data suggest that alteration of factors such as glucagon‐like peptide‐1 (GLP‐1) produced by the upper intestinal tract is involved. Currently, no studies have focused on a non‐diabetic DJB animal model to determine its importance of the duodenum and proximal jejunum in maintaining normal glucose homeostasis. Normal C57BL/6J mice underwent duodenojejunal bypass (DJB), a surgery in which the distal end of the jejunum was connected to a small portion of the duodenum just distal to pylorus and bilopancreatic secretions where directed to the distal jejunum. Normal‐fed mice undergoing DJB display diabetic‐like pancreatic morphology. These mice showed a decrease in the percent area of beta‐cells (33%) as well as a decrease in beta‐cell proliferation (50%) compared to sham‐operated controls. However, surviving beta‐cells showed similar levels of pancreatic duodenal homeobox‐1 (Pdx‐1), GLUT‐2 expression, and similar beta‐cell size between DJB and sham‐operated groups. These results suggest the importance of the duodenum in maintaining an anti‐diabetic state in the normal mouse. Funded by Lawson Health Research Institute.Grant Funding SourceLawson Health Research Institute
Spectrin is sequestered to Enteropathogenic Escherichia coli pedestals
Authors: Ruetz Tyson , Guttman Julian 
Published: June 2021

Enteropathogenic Escherichia coli (EPEC) is a bacterial pathogen that colonizes the small intestine of humans, causing serious diarrhea that can result in death. Upon attachment to host cells, EPEC injects effector proteins that hijack numerous sub‐cellular components, which leads to the generation of actin‐rich pedestals located within the host cells beneath the bacteria. A key effector responsible for pedestal formation is the translocated intimin receptor (Tir). Because EPEC alters the functions of all major cytoskeletal components examined thus far (actin filaments, intermediate filaments and microtubules) we investigated another cytoskeletal protein, spectrin, to test the hypothesis that the spectrin cytoskeleton is also modified by these pathogens. Spectrin was immunolocalized during in vitro infections with wild‐type EPEC and compared to mutants defective in effector secretion as well as Tir‐specific bacterial mutants. Surprisingly, spectrin was sequestered to wild‐type EPEC pedestals, but not to sites of bacterial attachment using EPEC effector mutants. Western blots identified that spectrin levels were equivalent in both infected and control cells. Our findings provide the first evidence of spectrin involvement in pathogenic E. coli‐mediated disease, whereby spectrin is re‐localized to the pedestals of EPEC.Grant Funding SourceCIHR, NSERC