bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Sildenafil on Atrial Natriuretic Peptide Level in Rats Treated with Monocrotaline
Authors: AlJinabi Mukhallad M. , Khatib Said Y. , Mahmoud Sahar M. 
Published: May 2022

BackgroundPulmonary hypertension is associated with an increase in pulmonary vascular resistance leading to pulmonary vascular changes, right ventricular hypertrophy, and heart failure. Pulmonary hypertension can be induced in animal models similar to humans where the changes are comparable. Monocrotaline (MCT), an alkaloid derived from a toxic plant, can be used to induce pulmonary hypertension in animals. Sildenafil has been used to treat patients with pulmonary hypertension since it induces smooth muscle relaxation. Atrial natriuretic peptide (ANP) is a hormone secreted naturally from the atria of the heart. An increase in ANP in hypervolemia and hypertension is beneficial since it induces a significant decrease in blood volume, therefore, lowers blood pressure. Studies showed that atrial natriuretic peptide combined with sildenafil reduces pulmonary arterial hypertension significantly. Cardiac hypertrophy due to pulmonary hypertension increases expression of myosin heavy chain β in the right ventricle of the heart.AimsTo explore the ability of sildenafil to alleviate PH induced by Monocrotaline (MCT) in rats and explore the ANP level before and after induction of PH, and the administration of sildenafil.MethodsSixty four male Wister rats, were divided randomly into 4 groups: Control A, (7 Rats). Group received MCT only (14 rats), at dose 60mg /kg body weight subcutaneously. Group C received a single injection of MCT subcutaneously at a dose of 60mg /kg for 3 weeks and then sildenafil at a dose of 50mg/kg/day from the beginning of the fourth week to the end of the sixth week (The reversal group) counted 23 rats. Group D received a single injection of MCT subcutaneously at a dose of 60mg /kg for 3 weeks at the same time sildenafil was given at a dose of 50mg/kg from day 1 to the end of day 21 (The prevention group) consisting of 20 rats.ResultsThe survival rate of the prevention group was the highest compared to other groups. The results revealed that MCT‐ treated rats and the reversal group showed a significant increase in ANP levels compared to the control one. The prevention group rats showed a significant decrease in ANP levels compared to both the reversal and the MCT‐ treated group. Fulton index ratio shows a significant increase in MCT treated rats and the reversal group compared to the control group, also it has an increasingly significant level to the reversal group compared to the prevention group. The percent of β‐ myosin heavy chain (MHC) is decreased significantly in the reversal group compared to both the MCT treated group and the control group. Nitric oxide (NO) levels were increased significantly in the reversal group compared to both the MCT treated group and the control group.ConclusionSildenafil significantly decreases ANP levels in rats treated with MCT, and it also decreases cardiac hypertrophy induced by MCT.
Acipimox Induces the Hepatic Accumulation of Long‐Chain Diacylglycerides and Triglycerides in Severely Burned Sprague Dawley Rats
Authors: Bhattarai Nisha , Vardarli Emre , Prasai Anesh , El ayadi Amina , Murton Andrew J. 
Published: May 2022

ObjectivePersistent lipolysis is a hallmark of severe burns, contributing to futile triglyceride cycling and the accumulation of lipid in ectopic tissues. It has been suggested that the administration of acipimox, a potent inhibitor of lipolysis, may blunt the hypermetabolic response to burns. However, what impact massive burns has on the accumulation of individual lipid species in the liver and how this is affected by acipimox treatment is unknown.HypothesisWe hypothesize that large burns results in the accumulation of lipotoxic species within the liver and that this can be prevented by administering acipimox.MethodsThirty‐two male Sprague Dawley rats were randomized to receive either a scald burn (~60% total body surface area) or sham procedure, performed under isoflurane general anesthesia. Afterwards, animals were further randomized to receive either acipimox (50 mg/kg/day) or vehicle (saline) by i.p. injection administered once a day for 7 days. On day 7, animals were euthanized and the liver snap frozen in liquid nitrogen. Liver lipids were extracted by using a chloroform:methanol (2:1) solution and diacylglycerol (DAG), triacylglycerol (TAG), free fatty acids (FFA) and cholesterol esters (CE) separated by thin‐layer chromatography. Afterwards, individual lipid classes were esterified to methyl esters, derivatized using heptane, and analyzed by gas chromatography (GC). The fatty acids C16:0, C18:0, cis/trans C18:1, cis 18:2, C20:0, C22:0, C24:0, and C22:6 were resolved by GC for each of the lipid classes examined.ResultsLiver weights were comparable between groups. Burn injury had no significant effect on the concentration of liver lipids compared to sham treated animals, irrespective of lipid class (P > 0.05). In contrast, the administration of acipimox significantly increased liver C16:0 (2.1‐fold; P < 0.05), trans C18:1 (2.5‐fold; P < 0.05), and cis C18:2 (5.5‐fold; P < 0.05) TAG content in burned animals, when compared to injured animals treated with vehicle. No effect of acipimox on liver lipids was observed in sham treated animals.ConclusionContrary to expectations, acipimox causes the accumulation of long‐chain TAGs in rat liver following massive burns, but this is not observed in response to burn injury alone. The ability of acipimox to cause unwanted hepatic metabolic side effects warrants further investigation before it is used clinically to treat massive burns.
A prospective clinical study on the mechanisms underlying Critical Illness Myopathy – A time‐course approach
Authors: Larsson Lars , Cacciani Nicoola , Skärlén Åsa , Wen Ya , Wang Xiang , Addinsall Alex B. , Llano‐Diez Monica , Li Meishan , Gransberg Lennart , Hedström Yvette , Bellander Bo‐Michael , Nelson David , Bergquist Jonas 
Published: May 2022

BackgroundCritical illness myopathy (CIM) is a consequence of modern critical care resulting in general muscle wasting and paralyses of all limb and trunk muscles, and prolonged weaning from the ventilator. CIM is associated with severe morbidity/mortality and significant negative socioeconomic consequences which has become increasingly evident during the current COVID‐19 pandemic, but underlying mechanisms remain elusive.MethodsTen neuro‐ICU patients exposed to long‐term controlled mechanical ventilation (CMV) were followed with repeated muscle biopsies 3times/week for up to 12 days. Single muscle fiber contractile recordings were conducted on the first and final biopsy. A multiomics approach was taken to analyze gene and protein expression in muscle and plasma at all six timepoints.Findingsi) A progressive preferential myosin loss, the hallmark of CIM, was observed in all neuro‐ICU patients during the observation period. The myosin loss was coupled to a general transcriptional downregulation of myofibrillar proteins and activation of protein degradation pathways, resulting in significant muscle fiber atrophy and loss in force generation capacity which declined >65% during the 12‐day observation period, ii) membrane excitability was not affected as indicated by the maintained compound muscle action potential amplitude upon supramaximal stimulation of upper and lower extremity motor nerves, and iii), analyses of plasma revealed early activation of inflammatory and proinflammatory pathways, as well as a redistribution of zinc ions from plasma in parallel with the activation of zinc transporters.InterpretationThe mechanical ventilation induced lung injury with release of cytokines/chemokines and the complete mechanical silencing uniquely observed in immobilized ICU patients affecting skeletal muscle gene/protein expression are forwarded as the dominant factors triggering CIM. It is therefore suggested that future intervention strategies should target the lung injury and the mechanical silencing in critical ill ICU patients.
Machine Learning‐Guided Engineering of Cre‐lox Recombination for Comprehensive Analysis of Neural Networks
Authors: Yamauchi Yuji , Ueda Mitsuyoshi , Aoki Wataru 
Published: May 2022

BackgroundNeural networks generate complex behaviors. However, the relationships between them have not been understood well. Thus, we have developed ‘functional cellomics’, which enables functional annotation of neural networks in a hypothesis‐free manner. The key is the stochastic labeling of opsin achieved by Cre‐mediated stochastic recombination. We designed a gene cassette, which contained two sets of lox variants, lox2272 and loxP, alternately. A transcription factor, QF2w, is interposed between loxP. Cre excises DNA with an exclusive choice of between lox2272 or loxP. When Cre excises lox2272, expressed QF2w induces opsin. Constructing a C. elegans strain carrying this gene cassette, we successfully implemented the stochastic labeling of opsin dependent on Cre induction [1]. However, the labeling rate of opsin was about 30 %. If a large subset of neurons is labeled by opsin, it becomes difficult to distinguish the function of each neuron. In this study, we demonstrated a strategy to precisely control the labeling rate of opsin by machine learning‐guided engineering of Cre‐lox recombination.MethodIn our genetic circuit, the opsin coding gene is expressed in neurons where Cre‐lox recombination occurs between lox2272 sequences. Therefore, we hypothesized that the labeling rate of opsin would be reduced by using lox2272 variants, which is difficult to be excised by Cre. Thus, we generated a library of randomized lox sequences by PCR and introduced them in Saccharomyces cerevisiae. We then induced Cre in the S. cerevisiae and extracted DNA from S. cerevisiae. We used NGS to assess the excision rate of the lox2272 variants. To develop a machine learning model to predict the excision rate of the lox2272 variants, we trained a Gaussian process (GP) model using data containing lox2272 sequences and their excision rates by Cre. Approximately 1000 lox2272 variants were randomly selected as training data and 100 variants were selected to test the prediction accuracy.Results and DiscussionWe quantified the excision rates of over 2000 lox2272 variants by NGS and successfully found lox2272 variants with excision efficiencies ranging from 0.05% to 100%. The results of the NGS analysis were confirmed by qPCR. Next, we created a GP model and observed a high correlation between the actual and predicted cleavage rates of the test data. Using the GP model, we predicted the efficiency of the unevaluated lox2272 sequence and successfully identified lox2272 variants that had various cleavage rates. These results demonstrate the feasibility of precise control of opsin labeling rates in functional cellomics [2].[1] Aoki et al, Sci Rep, 8, 10380, 2018[2] Yamauchi et al, submitted
Effect of Heparin on the Formation and the Healing of Kissing Gastric Ulcers in Rats
Authors: Sakhno Denis , Efimov Aleksei , Sigua Badri , Filaretova Ludmila 
Published: May 2022

The incidence of gastric ulcers remains at a fairly high level: it is diagnosed annually in 7‐14% of the adult population. Despite the decrease in morbidity and the development of diagnostic methods as well as effective treatment, the number of complications such as bleeding and perforation is increasing. One of the significant pathological factors leading to the gastric injury is disturbances in blood flow through mucosal microvessels (providing oxygen and nutrients). In this regard, it becomes relevant to study drugs that affect the rheological properties of blood and microcirculation.This study aimed to investigate the effect of heparin on the formation and the healing of the experimentally induced gastric ulcers in rat. Adult male Sprague‐Dawley rats weighing 230‐250 g were used after 24 h preliminary fasting. Gastric ulcers were produced by luminal application of 60% acetic acid to an area clamped with a pair of forceps (kissing ulcer model developed by S. Okabe) in anesthetized rats. Day 4 after the application (Day 0) was chosen as the time point for the ulcer formation, and Day 7 was chosen as the time point for incomplete ulcer healing. Heparin was injected at a dose of 1000 U/kg (s.c., once a day). While studying the effect on the ulcer formation, heparin was injected daily from Day 0 to Day 3. While studying the effect on the ulcer healing, heparin was injected daily from Day 4 to Day 6. Control rats were injected with saline. The blood hemoglobin levels were evaluated before the acid application surgery and in the end of experiments.The heparin injection before the ulcer formation resulted in a decrease of the ulcer area. The average area of kissing ulcers in heparin‐treated group was significantly smaller than that in the control group (p <0.05). The ulcer healing was significantly accelerated in the heparin‐treated group in comparison to the control group (p < 0.05). Blood hemoglobin levels were decreased in both heparin‐treated and control groups without significant differences between the groups.The results suggest that heparin therapy has the potential to accelerate gastric ulcer healing and prevent their formation.
In vitro Investigation of the Role of NCBE in Inflammation Induced Cerebrospinal Fluid Hypersecretion by the Choroid Plexus
Authors: Friis Kathrine A. , Johnsen Laura Ø. , Damkier Helle H. 
Published: May 2022

Post‐hemorrhagic hydrocephalus (PHH) can be the result of inflammation or deposition of FeCl3 in the choroid plexus (CP) after intraventricular hemorrhage (IVH). The hemorrhage leads to increased CSF secretion from the CP also known as the blood‐CSF‐barrier (BCSFB). The precise molecular mechanism is unknown, but the Na+ dependent Cl‐/HCO3‐ exchanger, NCBE, located in the basolateral membrane of the CP epithelia has been suggested as a possible facilitator of CSF hypersecretion.The aim of this study is to investigate the role of the NCBE located in the CP epithelia after inflammation or deposition of FeCl3in relation to the development of PHH. An in vitro model of the BCSFB was established and validated. The model was generated from mouse pup CP epithelial cells. The cells were treated with either TNF‐□, IL‐1□, LPS or FeCl3. NCBE protein expression of the CP epithelial cells was determined by immunoblotting.The CP epithelial cell cultures showed typical cobblestone‐like morphology, polarization and formed an intermediate tight barrier demonstrated by TEER values of ~ 100 Ω*cm2and expression of tight junctions. Compared with controls TNF‐□ decreased NCBE expression by 23.8 % after 24 h (p=0.0048, n=6/group). IL‐1□ had same effect with 28.3 % decrease after 24 h (p=0.0018, n= 6/group) persisting with a decrease of 88.5 % after 3 and 82.4 % after 7 days (p=0.0004 and p=0.0035, n=6/group). LPS had no effect on NCBE expression(n=5/group). FeCl3 increased NCBE expression by 52 % after 24 h (p=0.024, n=7/group) followed by a decrease of 57.8 % after 7 days (p=0.043, n=3/group).We hypothesized that IVH‐induced CP inflammation or FeCl3deposition leads to hydrocephalus by increasing the expression of the basolateral NCBE in the CP cells which leads to an increased rate of CSF secretion. However, the preliminary results suggest a decrease in expression of NCBE after inflammation whereas only an increase in NCBE expression was seen after FeCl3 deposition.In conclusion, NCBE expression of the CP epithelium in cultures decreases under pro‐inflammatory conditions and increases after FeCl3 deposition. Further studies are needed to define the pathways that lead to regulation of NCBE following hemorrhage.
Morphometrical Description of the Left Ventricular Summit Vascular Triangle
Authors: Batko Jakub M. , Krawczyk‐Ożóg Agata , Pękala Jakub , Hołda Mateusz K. 
Published: May 2022

BackgroundPrecise anatomical description of coronary vascular topography in the epicardial area adjacent to left atrial appendage (LAA) is crucial for many procedures performed in this region. The aim of this study was to assess the mutual relations between branches of left coronary artery and great cardiac vein in the left ventricular summit region and to determine their neighborhood with the LAA.MethodsLeft coronary artery with its branches, great cardiac vein and selected cardiac structures were segmented from 200 contrast enhanced computed tomography scans and visualized using three dimensional semi‐automatic algorithms.ResultsIn 97.0% of cases the area between left coronary artery branches and great cardiac vein had triangular‐like shape, with area of 253.0±160.0mm2. The length of the left anterior descending and left circumflex coronary artery sections forming the triangle sides were 24.6±8.8mm and 20.8±6.5mm, respectively. The mean length of the triangle base formed by great cardiac vein was 26.2±11.3mm. On average, 78.8±25,3% of the triangle area was covered by LAA. In 30.5% the ramus intermedius coronary artery intersected the triangle. Within the triangle, the Dg1 was present in 53.0% of hearts, the Dg2 in 4.5%, Mg1 in 29.0% and Mg2 in 3.5%.ConclusionsThis study provided detailed morphometrical description of the left ventricular summit vascular triangle. The proximal parts of the left coronary artery branches are closely adjacent to LAA in most cases. Three‐dimensional visualizations of coronary vessels and LAA may lead to increased safety of invasive procedures performed in this region.
Differential responses of receptor tyrosine kinases C‐Met and EGFR in mice
Authors: Xue Yuhua , Mars Wendy M. , Bowen William , Orr Anne , Stoops John , Michalopoulos George K. 
Published: May 2022

In previous studies, we have demonstrated the critical roles of EGFR and HGFR (c‐Met) for liver regeneration and for conversion of hepatocytes to cholangiocytes by a “clean” partial hepatectomy model, in which hepatocytes and cholangiocytes grow rapidly and synchronously. In contrast, the vast majority of liver diseases involve a prolonged pathologic duration, therefore multiple types of cells participate and play different roles in the variant stages. However, it is not fully understood how EGFR and Met play their roles in this complicated setting. In this study, we explore the role of MET and EGFR signaling pathways in biliary injury after common bile duct ligation. Mice with inhibition of EGFR signaling alone (EGFRi) showed abolished hepatocyte proliferation and biliary duct cell proliferation (Ki67 immunochemistry staining) at 2, 5, and 7 days after BDL. However, Met knockout mice (KO) showed increased proliferation of cholangiocytes at 2, 5, and 7 days. Met KO mice subjected to BDL surgery had an increase of the CK19‐ marked ductular reaction at 2, 5, and 7 days. In contrast, EGFRi mice showed a reduced ductular reaction at the same time point. There was enhanced immunohistochemistry for Sox9 in EGFRi mice, but absence of its expression in Met KO mice at 7 days post‐BDL. From western blot results of total liver tissue lysate, we found increased EpCAM expression after BDL at 7 days in Met KO but not in EGFRi mice. In addition, we also observed that both p‐Merlin and cleaved p‐Mst1, components of the Hippo pathway, decreased only in Met knockout mice. Mice with combined disruption of Met and EGFR signaling became very ill by 24 hours and died at 1 to 2 days after bile duct ligation. From Kaplan‐Meier analysis, both EGFR inhibition and Met knockout mice had decreased survival rates starting at 11 days, though the survival rate of Met KO mice was overall much better than EGFRi mice by around 40%. We also observed that p‐Ezrin (Thr567) was downregulated in either Met KO or EGFRi mice, while the total Ezrin expression did not change.ConclusionsOur study demonstrates that both c‐Met and EGFR control biliary response to bile duct ligation. The cholangiocyte responses, however, were very different between these two receptors. Their combined disruption led to acute liver failure and early death following bile duct ligation. The receptor tyrosine kinases c‐Met and EGFR may play different roles in the biliary injury‐repair responses, including proliferation, trans‐differentiation, and bi‐potential progenitor cells activation.
Effects of flow and polycystin‐1 dysfunction on ATP release in the inner medullary collecting duct of the kidney
Authors: van Megen Wouter H. , van Waes Charlotte R. , Peters Dorien J. , van der Wijst Jenny , Hoenderop Joost G. 
Published: May 2022

After filtration of blood by the kidney, the remaining pro‐urine flows through the renal tubular system with a flow rate that can vary considerably. These variations in pro‐urinary flow can be sensed by mechanosensing proteins on the epithelial cells lining the renal tubules. An important mechanosensing protein is polycystin‐1 (PC1), which is thought to be a key sensor of fluid flow. Mutations in PC1 give rise to autosomal dominant polycystic kidney disease (ADPKD), which is characterized by the formation of fluid‐filled cysts in the kidney. Previous research has highlighted a role for the ATP release channel pannexin‐1 (PANX1) in the increased flow‐induced ATP release in a Pkd1‐/‐ cell model of the distal convoluted tubule. However, it remains unclear if other purinergic signaling components are also involved, especially in the collecting duct.Using the mouse inner medullary collecting duct 3 (mIMCD3) cell line in combination with microfluidic experiments, we show here that a similar flow‐induced ATP release is present in Pkd1‐/‐ mIMCD3 cells under low (0.32 mL/min) or high (1.27 mL/min) flow application for 1 minute compared to wildtype (WT) mIMCD3 cells. This is despite a six‐fold increase in the expression of Panx1 observed in Pkd1‐/‐ mIMCD3 cells. Moreover, application of the specific PANX1‐inhibitor BB‐FCF revealed that PANX1 did not drive the high flow‐induced increased ATP release. Accordingly, intermediate flow application (0.47 mL/min) for 3 hours did not increase Panx1 expression in WT mIMCD3 cells compared to the static condition. Flow did not increase the expression of any of the known purinergic receptors in the collecting duct cells compared to the static condition. We did observe a two‐fold increase in gene expression of the putative ATP release channel connexin‐30.3 (CX30.3) compared to static conditions. Moreover, we also report a three‐fold increase in CX30.3 gene expression in Pkd1‐/‐ mIMCD3 cells compared to WT cells.In conclusion, we show here that flow‐induced purinergic signaling in the collecting duct greatly differs from previously published work on the distal convoluted tubule. Specifically, in the inner medulla of the collecting duct, PANX1 may not be the key flow‐regulated ATP release channel. Instead, CX30.3 may facilitate flow‐induced ATP release in this segment in health and in ADPKD.