bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of HIF normalizes oxygen utilization and oxygenation in the diabetic kidney
Authors: Palm Fredrik , Fasching Angelica , Nangaku Masaomi , Hansell Peter 
Published: June 2021

Hyperglycemia results in increased oxygen consumption (QO2) and decreased oxygen tension (pO2) in the kidney. We hypothesize that activation of hypoxia‐inducible factors (HIF) protect against diabetes‐induced alterations in kidney function and oxygen metabolism.The experimental groups consisted of control and streptozotocin‐induced diabetic rats with and without chronic cobalt chloride (CoCl2; inducer of HIF; n=9–10/group).Diabetic rats had increased glomerular filtration rate (2.3±0.2 vs 1.5±0.2 ml/min/kidney; P<0.05) and CoCl2 prevented this increase (1.5±0.1 ml/min/kidney). QO2 was increased in the diabetic kidney (23±2 vs 11±2 μmol/min/kidney; P<0.05) and CoCl2 prevented this alteration (12±2 μmol/min/kidney). Tubular sodium transport (TNa)/QO2 was decreased in the diabetics (14±2 vs 33±8; P<0.05), which was prevented by CoCl2 (25±4). Diabetic kidneys had reduced pO2 in both cortex and medulla compared to control (29±1 vs 45±2 and 22±1 vs 30±1 mmHg, respectively; both P<0.05). CoCl2 prevented these decreases (cortex 42±1; medulla 39±1 mmHg). All investigated parameters were unaltered by CoCl2 in control rats.Diabetes‐induced alteration in kidney oxygen metabolism is prevented by HIF activation via two different mechanisms. Normalizing GFR, which reduces tubular electrolyte load, and maintaining TNa/QO2 contribute to normal QO2 and pO2 in the diabetic kidney. Early pharmacological activation of the HIF system may prevent the development of diabetic nephropathy. Funding: NIH/NIDDK DK077858 and Swedish Research Council.
Effect of diet and age on expression of renal NOS isoforms and splicing in female Zucker rats
Authors: Slyvka Yuriy , Inman Sharon R , Nowak Felicia V 
Published: June 2021

The underlying hypothesis is that changes in renal oxidative status and nitric oxide synthases (NOS) that occur with progression of nephropathy in obesity‐related Type 2 diabetes mellitus (T2bDM) will be altered in response to an antioxidant‐fortified (AO) diet. Female obese Zucker rats (fa/fa), a model of T2bDM, were studied at 6, 13 and 20 weeks of age, on a regular (REG) or AO diet. Glomerular filtration rate (GFR) was measured and NOS isoforms (n‐neuronal, e‐endothelial and i‐inducible) analyzed with Western blots. The AO diet resulted in better preservation of GFR in 20 week animals. In rats on REG diet eNOS, iNOS and nNOS were highest at 13 weeks, while rats on the AO diet showed significantly decreased levels at this time point. Thus levels of all three isoforms were decreased at 13 weeks in animals on the AO diet compared to animals on the REG diet. This may indicate a protective effect of AO diet at earlier stages of nephropathy. Multiple monomeric splice forms, up to 8 for eNOS and iNOS, and 5 for nNOS were detected; 4–5 dimeric forms were also detected for each isoform. Increased prevalence of active monomers and dimers and detection of a greater number of splice variants were observed in the AO diet groups at 6 and 20 weeks.ConclusionAO diet has a protective effect on renal function in females that may be due, at least in part, to changes in NOS protein expression and activity. Supported by NIH R15 DK073066 to SRI and FVN.
Extracellular chloride modulates the desensitization kinetics of acid‐sensing ion channel 1a (ASIC1a)
Authors: KUSAMA NOBUYOSHI , Benson Christopher J 
Published: June 2021

Acid‐sensing ion channels (ASICs) have Cl−‐binding sites in the extracellular domain that are highly conserved between ASIC isoforms. In this experiment, we investigated the effect of Cl−‐substitution on heterologously expressed ASIC1a current and ASIC current in hippocampal neurons by whole‐cell patch‐clamp method.Substitution of Cl− with the impermeable and inert anion, methansulfonate (MeS) did not alter the maximal current amplitude, pH sensitivity or steady‐state desensitization. However, the rate of desensitization was faster in MeS than in Cl−, and the tachyphylaxis of ASIC current was attenuated in MeS. Other anions (thiocyanate, Br− and I−) also modified the kinetics of desensitization and tachyphylaxis.Next, we studied the effect of mutation of Cl−‐binding sites. The pH sensitivity of mutants (K211A, R309A, E313A) was similar to that of wild type channel. However, these mutants showed a faster desensitization and an attenuated rundown. These mutations abolished the effect of anion substitution.Finally, we investigated the effect of Cl− substitution in hippocampal neuron. The modulation of the ASIC1a current in hippocampal neuron was similar to that in heterologously expressed ASIC1a.In addition to sensing pH changes, modulation of ASICs by anion fluxes associated with pathological conditions further positions the channels to sense changes in the extracellular environment.
Voltage‐gated chloride channels in storage cells of the anhydrobiotic eutardigrade Richtersius coronifer
Authors: Willumsen Niels J , Jensen Christel Barker , Ramløv Hans 
Published: June 2021

Tardigrades comprise polyextremophilic species that can survive in an anhydrobiotic state for years. Anhydrobiosis may be dependent on properties of the free floating storage cells found in the body cavity of all tardigrades. We studied ion channels in the storage cell membrane with patch clamp technique, using native cells from the eutardigrade Richtersius coronifer.In cell‐attached configuration the most frequently encountered ion channel had a linear i/V‐relationship with a reversal potential (Vrev) of ~0.4 mV (n ≥6). The single‐channel conductance was 82.4±0.0 pS (mean±SE, n≥6). Binomial analysis of patches with 2–4 active channels showed stochastic behavior. The open‐state probability increased with the pipette potential, indicating voltage‐gating. In whole‐cell configuration the currents showed outward rectification with Vrev = −18.2±1.1 mV (mean±SE, n=24), closest to the equilibrium potential for Cl−. Perfusion with Na‐gluconate Ringer right‐shifted Vrev from −19.5±1.9 to 4.6±1.3 mV, and the current decreased significantly (mean±SE, n=5), confirming that a significant component of the whole‐cell current is attributed to Cl− channels. This was verified by perfusion with KCl Ringer (n=5) and addition of BaCl2 (n=7), neither of which significantly changed Vrev. Future studies are needed to firmly establish the identity and function of the demonstrated ion channel in storage cells.
In Xenopus oocytes, stimulation of the electrogenic Na/HCO3 transporter NBCe1 by IRBIT can be explained by relief of transporter autoinhibition and is unaffected by endogenous phosphatases.
Authors: Lee Seong‐Ki , Parker Mark , Boron Walter 
Published: June 2021

Other have shown in Xenopus oocytes that NBCe1 lacking an amino‐terminal (Nt) autoinhibitory sequence has a ~3‐fold greater transport activity than full‐length NBCe1. In a separate study, it was reported that co‐expression of full‐length NBCe1 with its Nt binding partner IRBIT results in a ~7‐fold stimulation of transporter activity. At face value these data suggest that the stimulatory action of IRBIT cannot be explained solely by relief of autoinhibition. However, these data pertain to different splice variants of NBCe1.In the present study, we work only with the pancreatic splice form NBCe1‐B. We find that, compared to oocytes expressing full‐length NBCe1‐B alone, oocytes expressing (1) a mutant NBCe1‐B that lacks the autoinhibitory sequence manifest a 7.5‐fold greater transporter activity (2) full‐length NBCe1‐B plus IRBIT manifest a 5.2‐fold greater transporter activity.Oocytes have endogenous protein phosphatase 1 (PP1) and PP1 is reported to deactivate IRBIT following binding at a non‐consensus PP1‐binding site ‘KQIQF’ in IRBIT. Thus we hypothesized that the full stimulatory effect of IRBIT was masked by the action of endogenous PP1. However, we find that removing the putative PP1 binding site in IRBIT does not result in a substantial increase in NBCe1‐B stimulation. Conversely an IRBIT in which we replaced ‘KQIQF’ with a well characterized PP1‐binding consensus sequence of the type ‘RVxF’ was unable to stimulate NBCe1‐B activity.In conclusion, our findings are consistent with a model in which the action of IRBIT is explained solely by relief of autoinhibition. The results are not confounded by endogenous oocyte PP1 activity, because the endogenous PP1 has no detectable functional interaction with the ‘KQIQF’ motif in overexpressed IRBIT.
Gene expression profiling and immune fluorescence implicate cellular redifferentiation induced by hypertonicity in primary cultured IMCD cells
Authors: Edemir Bayram , Klokkers Jens , Pavenstädt Hermann , Schlatter Eberhard 
Published: June 2021

The cells of the renal inner medulla are challenged with an environment consisting of high osmolality mediated mainly by Na+ and urea. High tonicity leads to the activation of the tonicity enhancer binding protein, which induces the expression of several transporters and enzymes. This in turn leads to the cellular accumulation of organic osmolytes thereby protecting the cells from high extracellular tonicity. Although several genes that are induced by tonicity are known, a global gene expression profile and analysis of pathways is missing. We used primary cultured rat renal inner medullary collecting duct cells which were cultivated for 6 days at 300, 600 or 900 mosmol/kg. Total RNA was isolated and prepared for hybridization on Rat Gene 1.0 ST GeneChip. Differentially expressed genes were identified using the BRB Array Tools and functional molecular network were identified with Ingenuity Pathway Analysis.Comparing cells grown in 300 vs. 600 mosmol/kg, more than 1600 and vs. 900 mosmol/kg more than 3300 genes were differentially expressed. In both cases the ratio between the up and down regulated genes was approximately one. While 1300 were common in both comparisons 290 at 600 and more than 2000 genes at 900 mosmol/kg were unique. Besides known genes the expression of several other genes were identified for which regulation by tonicity had not been described before. Cellular morphology was markedly modified with increases in culture medium tonicity. Tonicity induced actin reorganization and morphological changes at the cell to cell contacts. It also induced a hypertrophic phenotype. The adaptation to a higher tonicity is not only associated with massive changes in gene expression but also with changes in cell morphology. This implicates that tonicity induces cellular redifferentiation.
Polymorphisms of the lamina maturation pathway and their association with the metabolic syndrome: the DESIR Prospective Study
Authors: Fontaine‐Bisson Benedicte , Fumeron Frederic , Marre Michel , Dutour Anne , Badens Catherine , Levy Nicolas , Tichet Jean , Tregouet David‐Alexandre , Balkau Beverly , Morange Pierre‐Emmanuel 
Published: June 2021

Laminopathies are rare monogenic diseases, some of them exhibiting features of the metabolic syndrome. These diseases are mainly due to mutations in LMNA, encoding A‐type lamins. One LMNA polymorphism, rs4641, has been associated with the metabolic syndrome, but results have been controversial. We therefore investigated the effect of single nucleotide polymorphisms (SNPs) in the LMNA gene in combination with four other genes encoding enzymes influencing lamin post‐translational maturation on risk of metabolic syndrome (MS). Twenty‐three tagging SNPs characterizing the haplotypic variability of 5 genes (LMNA, ICMT, ZMPSTE24, FNTA, FNTB) were genotyped in 3916 French men and women who took part in the prospective DESIR study. Single‐locus and haplotype analyses were performed but did not detect any significant association with the risk of MS. No robust interaction between SNPs located in different genes on the risk of MS were neither identified. In conclusion, we did not observe any convincing evidence that common polymorphisms of the lamina pathway could modulate the risk of MS. The DESIR study was supported by INSERM‐CNAMTS.Grant Funding Source: INSERM
Rab 11 is associated with Nectin 2 positive vesicles in Sertoli cells at newly forming adhesion junctions with early elongating spermatids in rat testis
Authors: Young J'Nelle Sarah , Vogl Wayne 
Published: June 2021

Tubulobulbar complexes are podosome‐like structures that internalize intercellular junctions in the seminiferous epithelium. Near the ends of the complexes, enlarged swollen areas develop and separate away from the complexes forming double membrane vesicles. Although these vesicles are degraded by Sertoli cells, it also is possible that some of the junction molecules in the vesicles are sorted and are recycled to junctions assembling at other locations in the cell. In this study, we double label perfusion‐fixed and mechanically fragmented seminiferous epithelium of rat testis for Nectin 2 and Rab 11. The rabbit anti‐Nectin 2 antibody that reacts with rat protein was provided by Dr. Yoshimi Takai, Kobe University, Japan. As expected on the basis of data from studies in mice, Nectin 2 is found at adhesion junctions associated with late spermatids, and in vesicles at the ends of tubulobulbar complexes. Although Rab 11 is not associated with any of the Nectin 2 positive vesicles at tubulobulbar complexes, Rab 11 is associated with Nectin 2 positive vesicles at newly forming adhesion junctions attached to early elongating spermatids. Our data support the conclusion that some of the Nectin 2 being incorporated into newly forming adhesion junctions is from recycling pathways, possibly from junctions being internalized by tubulobulbar complexes. Supported by a NSERC discovery grant to AWV.Grant Funding Source: NSERC
Eps15, but not AP‐2, is recruited and essential for the formation of enteropathogenic E. coli pedestals
Authors: Lin Ann , Benmerah Alexandre , Guttman Julian 
Published: June 2021

Enteropathogenic Escherichia coli (EPEC) are extracellular pathogens that cause serious infantile diarrhea. The hallmark of EPEC pathogenesis is its ability to colonize the surface of gut epithelial cells and inject effector proteins to hijack sub‐cellular components, forming characteristic actin‐rich pedestals beneath the attached bacteria. Efficient formation of pedestals requires the phosphorylation of the EPEC effector protein Tir at Tyrosine 474 (Y474). Clathrin, a key component in receptor‐mediated endocytosis, was previously found to participate in pedestal formation. We examined the clathrin‐associated endocytic proteins AP‐2 and its binding partner, Eps15. We found that Eps15 is recruited to the pedestal together with clathrin while AP‐2 is not. Further analysis using GFP‐Eps15 mutants revealed that such recruitment does not require the AP‐2 binding domain at the Eps15 C‐terminus, confirming previous results that pedestal forms efficiently in the absence of AP‐2. RNA interference showed that pedestal formation is inhibited in the absence of Eps15, suggesting Eps15 is required to generate pedestals. Finally we showed that Eps15 recruitment to pedestals required Tir Y474 phosphorylation. These results reveal a novel internalization subversion strategy employed by extracellular pathogens, supporting the recent paradigm that endocytic proteins are important for EPEC‐mediated disease.Grant Funding Source: CIHR
Using QuickTime videos of cone beam computed tomography of the mandible in the instruction of first year dental students
Authors: Smith Kyle D , Lanphier Terry F , Jergenson Margaret A , Edwards Paul C , Saini Tarnjit S , Norton Neil S 
Published: June 2021

The mandible is a complex bony structure within the head. It either contains or has specific anatomical landmarks for several important nerves and vessels which provide innervation and vascular supply to teeth, bone, muscles, and surrounding soft tissues. As dental clinicians, it is important to have a thorough understanding of the anatomical structure and landmarks of the mandible. There are many procedures including anesthesia, restoring defective teeth, extraction of impacted third molars and placement of implants where the dentist must have a thorough knowledge of the osseous structure of the mandible. During the freshman year at Creighton University, first year dental students spend one semester in head and neck anatomy. This course is taught using both a traditional lecture format and cadaver laboratory dissection. We sought to utilize cone beam computed technology to offer 3‐dimensional anatomy as an adjunct to their education. A QuickTime video of the normal anatomy of the mandible using cone beam computed tomography images was created using axial, sagittal, and coronal planes. The video was distributed to the students as part of the regular course content. At the end of the course, students were provided a brief questionnaire to evaluate the resourcefulness of the video as an adjunct to their education.Grant Funding Source: Departmental
Development of a synchronous online microscopic anatomy course using virtual microscopy
Authors: Barbeau Michele , Rogers Kem 
Published: June 2021

The use of virtual microscopy has become a well established and accepted tool for microscopic anatomy instruction. This tool has been tested for its educational effectiveness and it has shown to be as effective as traditional microscopes.The popularity of distance education (DE) courses continues to increase as more students become comfortable with this method of teaching and as more courses are offered. Using the Wimba Collaboration Suite videoconferencing software, we are combining the technologies of virtual microscopy with synchronous videoconferencing to create an online microscopic anatomy course. Our institution has offered a traditional comprehensive microscopic anatomy course for decades. This course includes both lectures and traditional laboratories using microscopes. With online technologies, it is possible to offer the same course, including the laboratory exercises, as a DE course. Synchronous online courses allow many of the benefits of face to face instruction where the instructor can ask questions to check for understanding or the class can have a discussion. The combination of technologies allows this course to be offered to a much wider audience, including participants that are unable to attend campus.Grant Funding Source: Not available
Low cost, high impact video system for use in a gross anatomy laboratory
Authors: Goldman Evan Michael 
Published: June 2021

ResultsA customized wireless video system was developed for the gross anatomy lab at Philadelphia University. The system was designed to be extremely simple to set up and use. Minimal interaction with podiums, computers, or switches is required. The total price was kept extremely low ($1224) yet the system is high‐resolution and allows for live recording on digital media. The video system displays high‐resolution live video feeds on ten lab monitors with a setup time of less than one minute. With the system, instructors are able to relay details and images of noteworthy dissection techniques, structures, and pathologies to the entire class.ConclusionsViewing the dissections of multiple cadavers prepares students to understand the natural variations of human anatomy. Each cadaver also provides a glimpse into the person's medical history providing an opportunity to see, in situ, a variety of pathological states. For a variety of reasons students will often fail to see structures or interesting dissections on other group's cadavers within a lab. With the current video system, the instant availability of live video eliminates the barriers that had precluded students from viewing specimens throughout the room. This novel system within the anatomy laboratory now allows the instructor to provide interesting and pedagogically relevant content to all students simultaneously.
Use of CT Imaging to Enhance Learning of Gross Anatomy in Medical Curriculum
Authors: Nyauncho Clive P , Barlow John M , Christensen Kevin , Scoville Elizabeth A , Hassinger James P , Kumar Neha , Lachman Nirusha , Pawlina Wojciech 
Published: June 2021

The increasing dependence on radiologic diagnostic modalities in clinical practice has necessitated innovative teaching methods that introduce radiology into early medical curriculum. At Mayo Medical School cadaveric CT images are integrated into the first year gross anatomy course. Using post‐preservation, non‐contrast full body CT scans of their cadavers, medical students are able to correlate radiologic images to their dissection specimen. The AquariusNET thin client software used to view the images provides students numerous options for image manipulation including standard and oblique sagittal and coronal images and three‐dimensional renderings. Students are requested to record interesting findings from the imaging studies as part of an autopsy report. They are also provided with daily radiology learning objectives that require them to visualize specific anatomic structures. At the end of the course, students were comfortable accessing the cadaver CT data, correlating gross and CT anatomy and appreciating relationships of anatomic structures. They enjoyed interactions with radiology faculty and were more prepared to evaluate radiologic examinations.Grant Funding Source: Department of Anatomy
Effectiveness of a web‐based cross‐sectional anatomy learning tool (3D‐X) at improving students’ ability to interpret CT images
Authors: Dorosh Kyle , Bhattacharyya Siddhartha , Haase Peter 
Published: June 2021

BackgroundResidency programs are demanding an increased knowledge of cross‐sectional anatomy from entering physicians studying radiological imaging. In response to medical schools decreasing the time allotted to teaching anatomy and increasing self‐directed computer‐based learning, a web‐based learning tool (3D‐X) was developed to facilitate the study of cross‐sectional anatomy. The effectiveness of 3D‐X was assessed.MethodologyUndergraduate anatomy students (n=82) were randomly assigned to two groups. Each group participated in a 50‐minute learning session prior to identifying anatomical structures in CT images of the abdomen. Group 1 (control) spent the learning session studying the structures of the abdomen from prosection in an anatomy lab. Group 2 spent the first half of the lab session studying from a prosection in the anatomy lab and the second half in the computer lab using 3D‐X.ResultsA two‐tailed independent t‐test revealed a significant difference in test scores (mean% ± SD) between group 1 (58.4 ± 2.50, n=41) and group 2 (72.1 ± 2.44, n=41). Qualitative analysis revealed that students found the tool useful when presented as an adjunct to traditional gross anatomy.ConclusionThis study demonstrates that 3D‐X, when presented in addition to traditional gross anatomy, can improve students’ ability to identify anatomical structures in CT images, as well as improving anatomical knowledge of the abdomen.Grant Funding Source: N/A