bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of expired nitrogen (N2) after inhaling and exhaling fast a non‐N2 gas
Authors: Cruz Julio Cesar 
Published: June 2021

We don't know how much N2 is in the alveoli at the end of any expiration. The past April, expired N2 was presented after inhaling fast 1.9L of 79% Ar in O2 and exhaled fast (Cruz. FASEB J. 26:1082.3, 2012). Now, an attempt is made in simulating expired N2 after O2 inhalation from RV (1.4L) or FRC (4.L). The subject has a TLC=7.8L and a VC=6.4L. The model uses a VD=0.35L that is distributed from 0.018L at the apex, to 0.082L at the base of the lung. A N2=0.8 was assumed at RV or FRC. The model published (Cruz, Respir. Physiol. 86:1, 1991) has been improved by introducing the time variable to the exponential equation. Thus, the alveolar N2 fractions are now functions of lung volume and time. After exhaling to FRC or RV, 3.8L or 6.4L of O2 were inhaled in 2s and exhaled in 3s. The total expired N2 at FRC was 2.501L and at RV was 0.854L. The difference, 1.647, is exactly what would be exhaled if the total 2.08L of N2, present in the ERV, was diluted by O2. For clarity, only the classic maneuver is presented, which was executed fast to decrease the effect of alveolar gas diffusion and to avoid the cardiogenic oscillations during expiration (see Figure). The area under the expired curve was 0.854L and what remained at RV was 0.266, the balance of total N2 present at RV, prior to O2 inhalation. Remember that the curve is produced by the weighted average of uneven flows coming out from apex to base of the lung. Also, note the presence of Phase IV.Supported in part by Center of Teaching, Research and Services (CEIS).
Modeling the N2 expirogram obtained with a normal breath and with a forced maneuver
Authors: Caucha Luis Jhony , Cruz Julio Cesar , Melendrez Jose Maria 
Published: June 2021

We recently showed that the expired CO2, previously diluted in the alveoli, became more evident with the forced expiration and revealed the effect of alveolar CO2 diffusion from RV to ERV (Caucha's et al. FASEB J. 24:1063.5, 2012). Now, we modified Caucha's model to simulate a N2 expirogram, changing the number of Weibel's generations assigned for convection, convection‐diffusion and diffusion in the seven parallel regions from apex to base of the lung. The subject inhaled 1L of air from Functional Residual Capacity (FRC) and used 2.8s to exhale to FRC. The next breath, he inhaled 1L of 6.45% Ar, 72% N2 in O2 using 0.75s to inhale from FRC and exhaled to Residual Volume (RV) in 3.75s. The dotted lines are the experimental curves, and the ones obtained with the model, continuous lines, are shown in the Figure. The pulmonary blood flow was distributed exponentially from the 17th to 23rd generation; and the regional dead spaces were distributed with linear and exponential functions for the normal and force maneuver, respectively. While the number of generations for convection, convection‐diffusion and diffusion are constant for the seven parallel regions in a normal breath, in the force maneuver, the number of generations decreased for convection and increased for diffusion, from base to apex of the lung. In conclusion, the dilution of N2 is produced more at the base than at the apical regions of the lung, as a consequence of the uneven regional volume distribution during inhalation and exhalation.Supported in part by CEIS (Centro de Enseñanza, Investigación y Servicios).
Maternal obesity exaggerates insulitis in female NOD offspring mice
Authors: Wang Hui , Xue Yansong , Wang Baolin , Zhao Junxing , Yan Xu , Huang Yan , Du Min , Zhu Mei‐Jun 
Published: June 2021

BackgroundAccompanying dramatic increase in obesity, the incidence of type I diabetes (T1D) is rapidly increasing. The objective of this study is to explore impacts of maternal obesity (MO) on the incidence of T1D in female offspring using non‐obese diabetic (NOD) mice.Methods4‐wk‐old female NOD mice were randomly separated into two groups and fed a control or a high fat diet for 8 weeks before mating. Mice were maintained at their respective diets during pregnancy and lactation. All offspring were fed the control diet after weaning till necropsy at age of 16 weeks.ResultsFemale offspring (16wk‐old) born to obese dams showed increased body weight and respiratory exchange ratio, more severe islet lymphocytes infiltration (insulitis), accompanied with elevated p65 inflammatory signaling and TNFá protein in pancreas. In addition, MO resulted in impaired glucose tolerance and low serum insulin level in offspring, which was associated with increased phos‐AMPK and phos‐ACC.ConclusionMO resulted in exacerbated insulitis and inflammation in pancreas of NOD offspring mice, accompanied with impaired glucose intolerance and decreased insulin level. For the first time, data show that MO negatively impacts incidence of T1D in offspring, providing a possible explanation for the increased incidence of T1D in children. NIH 1R15HD073864; INBRE P20RR016474; USDA 2008–35203‐19084; 2009–65203‐05716
Postnatal development of mononuclear phagocytes in the mouse epididymis
Authors: Grigoryeva Lubov , Hill Eric , Da Silva Nicolas 
Published: June 2021

The epithelium lining the epididymis (site of sperm maturation and storage) is surrounded by mononuclear phagocytes (MPs, expressing dendritic cell and macrophage markers) that closely interact with adjacent epithelial cells. We mapped here their distribution during postnatal development in CD11c‐EYFP and CX3CR1‐GFP mice. MPs were present in the epididymis as early as 1 week after birth. The number of epididymal MPs gradually increased and, between week 4 and week 5 (puberty), they underwent major morphological changes. MPs progressively acquired a stellate/dendriform morphology and relocated from the interstitium to the peritubular region. Cellular bodies and lateral extensions were located at the base of the epithelium, while, in the initial segment, slender dendrites extended between epithelial cells towards the lumen. At week 5, MPs had acquired the overall appearance that we described previously in adult mice. In contrast, the peritubular region of the vas deferens (VD) was heavily populated by MPs during the early stages of postnatal development, long before puberty, possibly to prevent ascending pathogens from infecting the developing epididymis and testis. Our data will help better understanding the complex relationships between the immune and reproductive systems during development of the excurrent duct.Supported by NIH‐NICHD grant 1R01HD069623.
Profile of hypoxia inducible factor 1 alpha [HIF‐1a], vascular endothelial growth factor [VEGF], and its receptors in the postpartum uterine cervix of mice
Authors: Fike Molly , Stanley Robert , Jesmin Subrina , Mowa Chishimba 
Published: June 2021

The uterine cervix undergoes pronounced changes prior to term (pre‐partum) for a timely passage of the fetus, and also marked changes immediately after term or birth (post‐partum=pp) to enhance tissue repair in order to restore the tissue to its nonpregnant state. Because the vasculature plays a vital role in wound repair, it likely plays a similar function in pp uterine cervical repair, and since vascular endothelial growth factor (VEGF) is the key architect of vascular events and hypoxia‐inducible factor 1α (HIF‐1α) is the most potent transcription factor of VEGF, we examined the profile of HIF‐1α, VEGF, and VEGF receptors in the pp uterine cervix using timed‐pregnant (day 10) mice (C57BL6/129SvEv) allowed to undergo normal gestation and labor. Tissues (n=3) were harvested at an interval of 8hr, beginning with the emergence of the first pup (0hrs pp) to 48hrs pp, and analyzed for presence and quantity of HIF1‐α and VEGF and its receptors, Flt‐1 & KDR, using qRT‐PCR, Western blot and immunofluorescence. All molecules were found to be readily expressed during the initial part of pp, but declined by 2 days pp, relative to 0hrs pp. We conclude that HIF‐1α, VEGF, Flt‐1 and KDR likely play crucial roles in the wound healing of the pp uterine cervix. Studies to elucidate the potential mechanism underlying the actions of these molecules are ongoing.Funding: Office of Student Research, Appalachian State University.
Does the Embalming Process Induce Pseudo‐Aortic Dissection?
Authors: Rae Guenevere , Husain Mujtaba , Mark Jennifer , Elsayed Galal , Elsayed Mohammed , Kostrubala Anastasia , Schumacher Paul , Swartz William J 
Published: June 2021

The purpose of this study is to examine the incidence of aortic dissection and pseudo‐aortic dissection (dissection that has occurred as a result of the embalming process) in the gross anatomy lab. Eighty cadaveric specimens from two separate schools of medicine were screened for aortic dissection. Institution A received anatomical donations that had been initially embalmed by funeral services and embalmed a second time by the institution's director of anatomical facilities (N=31). Anatomical specimens screened at Institution B were subjected to a single embalming process at the institutional site (N=49). The incidence of suspected dissections from Institution A was 9.7%. The incidence of suspected dissections from Institution B was 6.1%. The cadavers suspected of incidence had their aortae removed and sectioned for gross and/or microscopic examination (N=3 from Institution A; N=3 from Institution B). Routine H&E preparations were used to confirm true aortic dissection after gross examination. Tissue changes that occur, as part of the embalming process, are important to identify when using aortic specimens for both teaching and research purposes. Results indicate that pseudo‐aortic dissections may occur during the embalming process and, consequently, resemble pathological disease.Grant Funding Source: none
The expression of thyroid hormone receptor mRNA and myosin heavy chain isoforms in mouse neonatal masseter muscle growth
Authors: Miwa Yoko , Sato Iwao , Sunohara Masataka , Shimada Kazuyuki 
Published: June 2021

ObjectivesThyroid hormone receptors (THRs) are composed of two isoforms, designated alpha and beta. It has been suggested that the thyroid hormone and THRs contribute to the regulation of masseter muscle development by affecting mitochondrial respiratory chain‐related biogenesis. However, the relationship between the mRNA transcript levels of THRs and myosin heavy chain isoforms (Myh1, Myh2, Myh4, Myh3, Myh6) in the mouse masseter muscle is unknown.MethodsQuantitative real‐time RT‐PCR was used to measure the expression of THR mRNAs in the developing postnatal mouse masseter muscle.ResultsThe expression of THR beta RNAs in the developing mouse masseter muscle decreased significantly from 0 to 10 days of age. Of the myosin heavy chains studied, Myh4 and Myh5 were the most highly expressed in the 10‐day‐old mice.ConclusionsThese data, along with the analysis of the RNA transcript levels of these genes, support a role for THRs as regulator of the growth and development of the postnatal mouse masseter muscle.
Mas‐related gene receptor D is expressed in human gut and modulates sensory pathways during intestinal inflammation in mouse models
Authors: Avula Leela , Buckinx Roeland , Pintelon Isabel , Adriaensen Dirk , De Winter Benedicte , Van Nassauw Luc , Timmermans Jean‐Pierre 
Published: June 2021

We have previously shown that the Mas‐related gene receptor D (MrgD) is expressed de novo in the mouse intestine during inflammation, specifically in intrinsic sensory neurons and mucosal mast cells (MMCs). We have also shown that MrgD deletion leads to increased MMC recruitment and sensory neuropeptide expression. These findings indicate role(s) for MrgD in the regulation of mastocytosis and (mast cell mediated)‐sensory neuromodulation. To further examine the effect of MrgD on intestinal function, we compared the motility of the ileum of healthy and Schistosoma mansoni‐infected wild‐type and MrgD−/− mice. Furthermore, to determine the mechanism of activation of MrgD in MMCs, calcium live cell imaging was performed on mouse bone marrow‐derived mast cells (BMMCs). MrgD deletion did not alter intestinal motility indicating that MrgD‐induced changes only influence the sensory pathways during inflammation. The MrgD ligand â‐alanine evoked a Ca2+ influx in a subset of BMMCs expressing MrgD, suggesting that â‐alanine can mediate MrgD activation during intestinal inflammation. As in mouse, MrgD was expressed in neurons and mast cells in the human intestine, suggesting translational potential. The findings justify the further exploration of MrgD as an experimental target in intestinal inflammatory pathologies, focussing on sensory perception and neuro‐immune interactions. Supported by FWO grant G.0179.08Grant Funding Source: N/A
An investigation of the dorsal scapular artery
Authors: Lichter Andrew , Raya Nischal , Saltzman Barbara S , Hankin Mark H 
Published: June 2021

The dorsal scapular artery (DSA) arises in the root of the neck and courses along the medial scapular border. It may arise either from the subclavian (SCA) ‐ a direct DSA, or indirectly from SCA via the transverse cervical artery (TCA) ‐ an indirect DSA. This cadaveric study (N=56) assessed the frequency of each variant, including any side and sex differences. We found a direct DSA in 74% of cases and an indirect DSA in 26% of cases; slightly more direct DSAs were observed on the left than on the right (80% vs. 68%; P<0.05). Regardless of side, the direct DSA almost always originated from the 2nd or 3rd part of the SCA. Within an individual, the origins of the DSAs were symmetrical in 70% of cases (P=0.005). The pathway of the direct DSA was also stereotyped: 67% of direct DSAs passed between the superior and middle trunks of the brachial plexus; 29% passed between the middle and inferior trunks; 4% passed inferior to the plexus. The indirect DSA arose from the TCA, which coursed posteriorly across the superior trunk; the indirect DSA never went through or inferior to the plexus. Improved understanding of the DSA will aid in clinical practice (e.g., in trapezius flap procedures, brachial plexus blocks). The proposed nomenclature will not only improve communication among practitioners, but also offers a simple resolution to the nomenclature discrepancies in current anatomical and surgical literature.Grant Funding Source: None
Asymmetry and vestigial structures in extant birds
Authors: Sartin Catherine E. 
Published: June 2021

It is commonly asserted that vestigial structures have a greater degree of fluctuating asymmetry than functional structures. The reason given for this link between vestigial structures and fluctuating asymmetry is relaxed selection pressure, as well as fitness benefits associated with redirection of energy and other resources to functional structures. Perhaps surprisingly, few studies have examined and quantified the amount of fluctuating asymmetry in paired vestigial structures, especially limbs.The present study is an attempt to fill this void and to test the following hypotheses: (1) Skeletal elements of limbs not used for locomotion will be more asymmetric than the skeletal elements of limbs used for locomotion (both within specimens and between groups), and (2) limb asymmetry will increase with time since the limb became vestigial. Four locomotor categories were examined: Tropicbirds (regularly use forelimb, but not hindlimb for locomotion), Flighted rails (regularly use both fore‐and hindlimb for locomotion), Grounded Rails (only use hindlimb for locomotion; lost flight recently), Ratites (only use hindlimb for locomotion; did not lose flight recently). Within each category, attempts were made to obtain a statistically‐significant sample (n ≥ 30) while still controlling for phylogeny and body size.Eight bilateral measures were taken, including maximum lengths and condylar breadths. Dimenstions were converted into percentage directional (%DA) and absolute (%AA) asymmetries. Results reveal significant fluctuating asymmetry in the forelimb elements of flightless taxa; however, tropicbirds do no show significant asymmetry in their hindlimb elements. Despite a small sample size of ratites, results also suggest a greater degree of fluctuating asymmetry in the forelimbs with time since the limb became vestigial.Grant Funding Source: Center for Functional Anatomy and Evolution, Johns Hopkins
The Effect of Posture on the Neck and Shoulder Suspension Apparatus of Humans: A 3D Biomechanical Analysis
Authors: Osborn Michelle L , Ge Jinghua , Melancon Keith P , Rau A Ravi P , Homberger Dominique G 
Published: June 2021

Clinical issues arising from bad posture and misalignment of the neck can significantly affect the quality of life of individuals. An understanding of the physical configuration and biomechanics of the neck and its associated parts in various postures is fundamental for successful treatments. We have re‐conceptualized the human head, neck and shoulder complex as a shoulder suspension apparatus, and we hypothesize that habitual bad postures lead to changes in the balance of forces acting on this apparatus. We tested our hypothesis by comparing the forces acting on the shoulder suspension apparatus of persons with different postures as ascertained from clinical x‐ray images. We applied the free‐body diagram force analysis to 3D models of the shoulder suspension apparatus in good and poor postures, which were reconstructed from data of x‐ray CT scans of a patient. Our biomechanical model suggests that in a good posture the head and neck are stabilized by the core muscles, the nuchal ligament is relaxed, and the shoulders are suspended from the head by fascia and the connective tissue of the clavotrapezius and cleidomastoid muscles. In poor postures, various muscles must be recruited to re‐balance the shoulder suspension apparatus, which, in turn, may cause tightened muscles, myo‐fascial pain, poor circulation to the head, head‐aches, and inflammation of the joints.Grant Funding Source: LSU Foundation to DGH
Radiofrequency preserves tendinous stiffness after experimental injury
Authors: Akamatsu Flávia Emi , Teodoro Walcy Paganelli Rosolia , Saleh Samir Omar , Martinez Carlos Augusto Real , Ribeiro Marcelo Lima , Andrade Mauro , Jacomo Alfredo Luiz 
Published: June 2021

BACKGROUNDCalcaneous tendon injuries are commonly seen as consequences of sports trauma. Ideal management should provide rapid healing so early mobilization can avoid tissue adhesions. Radiofrequency (RF) produces heat by molecular friction caused by polarity changes and its therapeutic use aims reduction of the local inflammatory response. We investigated the action of the RF on the calcaneous tendon healing process after experimental lesions in rats.METHODS AND MATERIALThirty adult male Wistar rats weighing 250 to 300 g were surgically submitted to bilateral partial transverse section of the calcaneous tendon. The right tendon was treated with RF whereas the left tendon served as control. On the third postoperative day, the rats were divided into three experimental groups consisting of ten rats each which were treated with monopolar RF (Tonederm™) adjusted to 650 kHz and 1–2w, for two minutes twice a week, until they were sacrificed on the 7th, 14th and 28th days, respectively. We studied collagen I gene expression and immunofluorescent staining to evaluate collagen Type I and III.RESULTSA larger amount of collagen I without correspondent collagen I gene expression was observed within 7 days.CONCLUSIONRF treatment preserves stiffness and accelerates the healing process of the calcaneous tendon and may be a useful tool in tendinous lesion management.
Remodeling and Regeneration in the Goldfish Heart
Authors: Haag Maria T , Grivas Jamie A , Lafontant Pascal J 
Published: June 2021

A remarkable ability for heart regeneration has been demonstrated in the zebrafish and giant danio, two members of the cyprinids family. While regenerative capacities appear widely distributed within genera, they can vary significantly in closely related species. Here we describe using light and electron microscopy the injury response and repair mechanisms in the heart of another cyprinid, the goldfish, following cautery injury to a small portion of the ventricular myocardium. We observed a robust inflammatory response in the first week consisting of infiltrating macrophages and heterophils. These inflammatory cells were identified in the lumen of spongy heart and in the compact layer of myocardium both adjacent and remote to the injury. Marked accumulation of collagen was observed during the second week in a border zone between healthy and injured myocardium, in adjacent sub‐epicardial regions, and was concurrent with a robust angiogenic response. The replacement of the ablated region of the ventricle was achieved by six weeks post‐cautery. PCNA‐positive cardiac myocytes (CM), as well as apparent de‐differentiated cardiac CM were present during repair. This data suggest that effective regeneration mechanisms operate in the injured goldfish heart, similar to that demonstrated in zebrafish and giant danio, and that cardiac regeneration may be widespread among cyprinids.Grant Funding Source: none
Pan‐omic Approaches to Study the Effect of Microgravity on Skin Endothelial Cells Submitted to Endotoxic Insult
Authors: Santos William J , Waddy Edward , Chakraborty Nabarun , Gautam Aarti , Hoke Allison , Jett Marti , Hammamieh Rasha 
Published: June 2021

Microgravity enhances bacterial virulence but depresses host immune response. Presumably, pathogenic insults occurring in space may trigger altered immunological pathways in host cells. Understanding this paradigm is essential to establishing proper wound care management. In this study, human microvascular endothelial cells were exposed to lipopolysaccharide (LPS), an endotoxin commonly found in gram‐negative bacteria, for two different time periods (4 h and 8 h). At the end of each time point the cells were fixed in RLT buffer and maintained in a fixed state until after the Space Transport System (STS) ‐135 landed.Genomics and transcriptomics analysis using high density mRNA and miRNA arrays and coherent functional analysis revealed the arrest of certain key immunological networks, elevated risk of tumorogenesis and neurological degeneration as a result of microgravity. Eliciting more disease footprints like osteo‐atrophy and adenocarcinoma, LPS assault at reduced gravity appears more lethal than at terrestrial gravity. Reduced gravity further altered angeogenesis and vasulogenesis promoting rheumatoid arthritis, tumor growth, and wound repair, some of the common ailments noticed in astronauts. The results were validated using a proteomics panel investigated by Luminex platform, a classic ELISA assay.
A Metabolic Pathways Diagnosis Test for Assessing the Development of Biochemistry Students’ Visualization Skills
Authors: Galembeck Eduardo , dos Santos Vanessa J S V , Anderson Trevor 
Published: June 2021

We have developed a Metabolic Pathways Visualization Skill Test (MPVST) to gain greater insight into our students’ abilities to comprehend the visual information presented in metabolic pathways diagrams. The test is able to discriminate students’ visualization ability with respect to six specific visualization skills that we identified as key to the understanding of metabolic map diagrams. Application of the MPVST to B. S. Biochemistry students showed that their visualization skills develop informally and progressively during their college years. Furthermore, the complex nature of biochemical pathways, together with students’ lack of familiarity with metabolic maps, suggests that it is important for instructors to spend more time than usual explaining visual representations to their students.This research was partially supported by FAPESP, Brazil.