Jove-Journal of Visualized Experiments最新文献

{"title":"Understanding the Development of Compensatory Pathways in a Mutant Malaria Parasite Harbouring Hypomorphic Allele of Plant-Like Kinases.","authors":"Himashree Choudhury, Manish Sharma, Utkarsh Gangwar, Nayla Siddiqui, Abhisheka Bansal","doi":"10.3791/67079","DOIUrl":"https://doi.org/10.3791/67079","url":null,"abstract":"<p><p>One of the mechanisms for subverting the effect of drugs by the malaria parasite is through rewiring of its transcriptome. The effect is more pronounced for target genes belonging to the multigene family. Plasmodium falciparum protein kinases belonging to the CDPK family are essential for blood stage development. As such, CDPKs are considered good targets for the development of anti-malarial compounds. The chemical genetics approach has been historically used to elucidate the function of protein kinases in higher eukaryotes. It requires the substitution of gatekeeper residue for another amino acid with a different side chain through genetic manipulation. Amino acid substitution at the gatekeeper position modulates the activity of a protein kinase and changes its susceptibility to a specific class of compounds known as bumped kinase inhibitors (BKIs) that help in the functional identification of the target gene. Here, we have exploited the chemical genetics approach to understand compensatory mechanisms evolved by a mutant parasite harboring a hypomorphic allele of cdpk1. Overall, our approach helps in identifying compensatory pathways that may be simultaneously targeted to prevent the development of drug resistance against individual kinases.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tissue Processing and Isolation of Primary Fibroblasts from the Human Vagina.","authors":"Vi Duong, Venkatesh Pooladanda, Caroline Mitchell","doi":"10.3791/65864","DOIUrl":"https://doi.org/10.3791/65864","url":null,"abstract":"<p><p>Pelvic organ prolapse is a disorder that seriously impacts the quality of life of women. It occurs when muscles and ligaments weaken and cause pelvic organs to drop lower in the pelvis, creating a bulge in the vagina. Surgery to correct pelvic organ prolapse has been a mainstay treatment. Recently, there has been growing interest in studying the tissue composition of patients with prolapse at the cellular level. There is currently little consensus regarding the effect of donor or patient age on cell-based therapies. Current published protocols for vaginal fibroblast isolation either concentrate on premenopausal tissue or neglect to comment on the age of donor tissue. Most existing protocols use animal models. The consistency of human vaginal tissue is denser than the tissues used in most protocols. In this study, human vaginal tissue was obtained primarily from older donors, which likely contributed to the failure of existing protocols. The aim of this study is to describe a standard protocol for reliably acquiring human vaginal fibroblasts, regardless of donor age and menopausal status. Results were reproduced using tissue from nine separate donors who underwent pelvic organ prolapse surgery. Six patients were postmenopausal, with the oldest donor being 78 years old. The median age of the tissue donors was 59. Here, we describe a reliable method for generating a fibroblast-enriched single-cell suspension using a combination of enzymatic and mechanical dissociation and cell suspension pooling of multiple vaginal biopsies from a single donor. Reliable isolation of human vaginal primary fibroblasts may be useful in the study of pelvic organ prolapse as well as microbiome-host interactions.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Inexpensive Adaptation of a Commercial Microwave Reactor for Solid Phase Peptide Synthesis.","authors":"Matthew A Kubasik, Sarah E Breslow, Kelley G Ross, Madelyn E Coogan, Colin M Gorman","doi":"10.3791/66937","DOIUrl":"https://doi.org/10.3791/66937","url":null,"abstract":"<p><p>A home-built apparatus to perform solid phase peptide synthesis (SPPS), assisted by microwave irradiation and heating, is presented. In contrast to conventional SPPS reaction vessels, which drain solvent and byproducts via a frit located at the bottom of the vessel, the presented apparatus employs a gas dispersion tube under vacuum to remove solvent, byproducts, and excess reagents. The same gas dispersion tube supplies nitrogen gas agitation of the SPPS beads during the reaction steps of coupling and deprotection. Microwave heating is beneficial for SPPS couplings of sterically hindered residues, such as alpha-aminoisobutyric acid (Aib), an alpha,alpha-dialkylated amino acid residue. This home-built apparatus has been used to prepare, via manual Fmoc SPPS methods, heptameric and octameric peptides dominated by the Aib residue, which is notoriously difficult to couple under standard room temperature conditions and reagents. Further, typical commercial microwave SPPS reactors are dedicated exclusively to SPPS synthesis rendering them inaccessible to non-SPPS users. In contrast, the presented apparatus preserves the versatility of the microwave reactor for conventional microwave acceleration of chemical reactions, as the apparatus is trivially removed from the commercial microwave reactor.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow Cytometry Analysis of Tissue Factor Expression in Human Platelets.","authors":"Marta Brambilla, Alessia Becchetti, Kevin Nallio, Marina Camera","doi":"10.3791/67356","DOIUrl":"https://doi.org/10.3791/67356","url":null,"abstract":"<p><p>A subset of circulating human platelets stores Tissue Factor (TF) intracellularly, the key activator of the blood coagulation cascade and thrombus formation. Upon platelet activation, TF is exposed on the cell membrane, where it binds to FVII, ultimately leading to thrombin generation. Considering that (1) levels of TF-positive platelets increase in various clinical settings, contributing to the patient's prothrombotic phenotype, and (2) different drugs can modulate platelet-associated TF expression, a standardized method for assessing TF-positive platelets is valuable, as its evaluation has been controversial in the past. Here, we outline a protocol for measuring the percentage of TF-positive platelets using flow cytometry in whole blood and platelet-rich plasma (PRP)/washed platelets. This protocol aims to provide detailed instructions for quantifying the percentage of TF-positive platelets by assessing the protein (1) intracellularly in resting conditions, and (2) on the cell surface, in both resting and activated conditions. The first section provides essential information for correctly performing blood withdrawal to ensure that pre-analytical procedures do not affect the results. Next, the protocol focuses on sample preparation and labeling procedures for flow cytometry analysis. Detailed steps for cell stimulation, labeling, fixation, and permeabilization -- where necessary -- are outlined. Finally, instructions for flow cytometry settings to correctly identify the platelet population and analyze TF-positive events are described. Lastly, the method includes the procedure for preparing PRP if TF-positive platelets are to be measured in isolated platelets. Since only a subset of platelets contains TF, it is important to ensure that these platelets are not lost during the centrifugation steps required to obtain PRP.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Mouse Model for Vascular Cognitive Impairment and Dementia Based on Needle-guided Asymmetric Bilateral Common Carotid Artery Stenosis.","authors":"Nadezda A Stepicheva, Zhongfang Weng, Sarah Cao, Lesley M Foley, Guodong Cao","doi":"10.3791/67092","DOIUrl":"https://doi.org/10.3791/67092","url":null,"abstract":"<p><p>Vascular cognitive impairment and dementia (VCID) results from vascular brain injury. Given VCID's high incidence, which is expected to continue rising as the population ages, it is critical to establish a robust animal model for the disease. This paper presents a novel method of creating a mouse model of VCID that is based on asymmetric bilateral common carotid artery stenosis, which mimics human chronic cerebral hypoperfusion caused by carotid atherosclerosis. Briefly, common carotid arteries (CCAs) are ligated to different gauge needles (32 G for the right CCA and 34 G for the left CCA) using 7-0 silk sutures followed by immediate needle removal. The remaining suture rings cause persistent blood flow reduction and long-term cognitive impairment associated with white matter injury, microinfarcts, and reactive gliosis, thus closely mimicking the pathogenesis of VCID. Importantly, in this needle model, the clinical representations do not revert with time, providing reliable long-term cognitive impairment. Moreover, the survival rate 24 weeks post surgery was 81.6%, which is higher compared to the other established models of VCID with a similar level of blood flow reduction. Additional advantages include low material cost and compatibility with MRI to monitor brain injury in live animals since no metal is implanted. The main challenge in employing the needle model of VCID is the requirement for developing advanced surgical skills since mouse CCAs are less than 0.6 mm in diameter and are very fragile. High-quality visual representation of the surgery will thus help researchers to master this technique and advance our understanding of VCID, potentially leading to the development of novel therapeutic modalities to decrease the devastating cognitive decline associated with VCID.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined Supine and Standing Imaging for Varicocele: An Improved Diagnostic Approach.","authors":"Zhiming Xu, Jianying Li, Shimei Li, Haoguang Huang","doi":"10.3791/66370","DOIUrl":"https://doi.org/10.3791/66370","url":null,"abstract":"<p><p>Varicocele, one of the main diseases affecting male reproductive health, relies heavily on angiographic diagnostic techniques for disease-related examination and assessment. Traditional varicocele angiography often employs a supine position to facilitate the relaxation of the groin area muscles, the insertion of the angiography catheter, and imaging. However, the supine position may cause blood reflux, thus underestimating the clinical incidence of varicocele, particularly resulting in missed diagnoses of right-sided or bilateral varicoceles. To address this issue, this study proposes the combined use of supine and standing positions for varicocele imaging. The standing position increases lower abdominal pressure, making the degree of varicosity more prominent in the images. Compared to the sole use of the supine position, the method employed in this study effectively reduces the misdiagnosis rate of right-sided or bilateral varicoceles. This approach aims to facilitate the early detection, diagnosis, and treatment of varicocele, effectively reducing the potential threat of the disease to male reproductive health. It also helps improve the accuracy of disease assessment, providing more references for selecting subsequent treatment plans.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rat Liver Perfusion and Primary Hepatocytes Isolation: An Old Procedure Crucial for Cutting-Edge 3D Organoids Culture.","authors":"Valentina Tiriticco, Gabriele Codotto, Benedetta Blarasin, Noel Salvoza, Marco Stebel, Claudio Tiribelli, Cristina Bellarosa","doi":"10.3791/66857","DOIUrl":"https://doi.org/10.3791/66857","url":null,"abstract":"<p><p>Primary hepatocytes are a commonly used tool for in vitro liver-related studies. However, the maintenance of these cells has always been a challenge due to the rapid loss of morphology, viability, and functionality in culture. A recent approach to long-term culture is the generation of three-dimensional (3D) organoids, an in vitro tool that can recapitulate tissues in a dish based on the marvelous ability of the liver to regenerate itself. Published protocols have been designed to obtain long-term functional 3D organoids from primary adult hepatocytes (Hep-Orgs). The 3D organoid cutting-edge tool requires the ability to isolate cells from adult tissue, and this initial step is crucial for a high-quality final result. The two-step collagenase perfusion, introduced in the 1970s, is still a valid procedure to obtain single hepatocytes. The present article aims to describe all the crucial steps of the surgical procedure, thereby optimizing the primary hepatocytes isolation procedure in the rat model. Moreover, particular attention is paid to the PREPARE guidelines to increase the likelihood of successful procedures and ensure high-quality results. A detailed protocol allows researchers to speed up and optimize the downstream work to establish 3D organoids from primary adult rat hepatocytes. Compared to 2D hepatocytes, Hep-Orgs were still viable and in active proliferation at Day 15, demonstrating a long-term potential.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acupoint Catgut Embedding Therapy for Abdominal Obesity Treatment.","authors":"Jie Chen, Luo Yang, Na Yue, Bingyue Zhang, Hongchun Li, Yuqun Cai, Zhibo Zheng","doi":"10.3791/67495","DOIUrl":"https://doi.org/10.3791/67495","url":null,"abstract":"<p><p>As the global economy grows and living standards improve, the rise in overweight and obese individuals poses a significant public health challenge. This trend is predominantly linked to lifestyle changes and poor dietary habits, resulting in increased abdominal obesity characterized by fat accumulation in the abdominal region and associated symptoms such as indigestion, constipation, and fatigue. Acupoint embedding therapy uses absorbable sutures inserted into specific acupoints for continuous stimulation, aiding in the treatment of abdominal obesity, metabolic issues, and digestive disorders. Its main goals are to regulate metabolism, improve digestion, and reduce fat. This paper offers a thorough exploration of the comprehensive management of thread-embedding acupuncture for obesity treatment. It meticulously outlines critical aspects of patient management and material preparation and provides precise guidance on acupoint selection, surgical procedures, and postoperative care. This structured treatment protocol aims to ensure procedural safety and efficacy, thereby optimizing clinical outcomes for patients with abdominal obesity and ultimately improving their overall quality of life.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of Regulated Ergot Alkaloids in Food Matrices by Liquid Chromatography-Trapped Ion Mobility Spectrometry-Time-of-Flight Mass Spectrometry.","authors":"Alfonso Narváez, Laura Gámiz-Gracia, Ana M García-Campaña, Maykel Hernández-Mesa","doi":"10.3791/67484","DOIUrl":"https://doi.org/10.3791/67484","url":null,"abstract":"<p><p>Ion mobility mass spectrometry (IMS) acts as an additional separation dimension when integrated into liquid chromatography-mass spectrometry (LC-MS) workflows. LC-IMS-MS methods provide higher peak resolution, enhanced separation of isobaric and isomeric compounds, and improved signal-to-noise ratio (S/N) compared to traditional LC-MS methods. IMS provides another molecular characteristic for the identification of analytes, namely the collision cross section (CCS) parameter, reducing false positive results. Therefore, LC-IMS-MS methods address important analytical challenges in the field of food safety (i.e., detection of compounds at trace levels in complex food matrices and unambiguous identification of isobaric and isomeric molecules). Ergot alkaloids (EAs) are a family of mycotoxins produced by fungi that attack a wide variety of grass species, including small grains such as rye, triticale, wheat, barley, millet, and oats. Maximum levels (MLs) of these mycotoxins have been established in several foodstuffs, as detailed in the Commission Regulation EC/2023/915. This new legislation includes six main EAs and their corresponding epimers, so an efficient methodology is required to properly distinguish these isomeric molecules considering their co-occurrence. Therefore, the goal of this protocol is to show how the integration of IMS in LC-MS workflows contributes to the separation of isomeric EAs, enhancing the selectivity of the analytical method. Additionally, it illustrates how the generation of CCS libraries through the characterization of analytical standards provides higher confidence for the identification of mycotoxins. This protocol is designed to clearly explain the benefits of implementing IMS in food safety, taking as an example the determination of EAs in cereals. A QuEChERS-based extraction followed by an LC-trapped ion mobility spectrometry (TIMS)-MS analysis provided limits of quantification ranging from 0.65 to 2.6 ng/g with acceptable accuracy (although low recovery for ergotaminine) at 1.5x, 1x, and 0.5x the ML and exhibited a negligible matrix effect.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of the Longa Middle Cerebral Artery Occlusion Method for Complete Reperfusion.","authors":"Rok Ister, Marta Pongrac, Marina Dobrivojević Radmilović","doi":"10.3791/66720","DOIUrl":"https://doi.org/10.3791/66720","url":null,"abstract":"<p><p>The middle cerebral artery occlusion model serves as the primary animal model for studying ischemic stroke. Despite being used in research for over three decades, its standardization remains inadequate. Predominantly conducted on rats and mice, the procedure poses challenges due to mice's smaller and more fragile nature. Unlike the Koizumi common carotid artery method, the Longa external carotid artery is the sole intraluminal filament stroke model ensuring complete reperfusion post-ischemia. This aspect holds critical significance for studies investigating reperfusion phenomena. The surgical modifications demonstrated in this article ensure continuous blood flow from the common carotid artery throughout the ischemic phase and after the reperfusion onset. The goal of these modifications is to selectively occlude the middle cerebral artery by keeping the perfusion uninterrupted in branches proximal to the middle cerebral artery during the ischemia period. Furthermore, the onset of reperfusion is sudden and can be precisely controlled, thereby modeling endovascular thrombectomy in human medicine more accurately. Our aim in presenting this comprehensive video article is to ease the training of new surgeons and promote the standardization of surgical procedures within the scientific community.</p>","PeriodicalId":48787,"journal":{"name":"Jove-Journal of Visualized Experiments","volume":" 213","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}