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1.
J Am Coll Cardiol ; 84(2): 165-177, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38960510

RESUMO

BACKGROUND: Conventional low-density lipoprotein cholesterol (LDL-C) quantification includes cholesterol attributable to lipoprotein(a) (Lp(a)-C) due to their overlapping densities. OBJECTIVES: The purposes of this study were to compare the association between LDL-C and LDL-C corrected for Lp(a)-C (LDLLp(a)corr) with incident coronary heart disease (CHD) in the general population and to investigate whether concomitant Lp(a) values influence the association of LDL-C or apolipoprotein B (apoB) with coronary events. METHODS: Among 68,748 CHD-free subjects at baseline LDLLp(a)corr was calculated as "LDL-C-Lp(a)-C," where Lp(a)-C was 30% or 17.3% of total Lp(a) mass. Fine and Gray competing risk-adjusted models were applied for the association between the outcome incident CHD and: 1) LDL-C and LDLLp(a)corr in the total sample; and 2) LDL-C and apoB after stratification by Lp(a) mass (≥/<90th percentile). RESULTS: Similar risk estimates for incident CHD were found for LDL-C and LDL-CLp(a)corr30 or LDL-CLp(a)corr17.3 (subdistribution HR with 95% CI) were 2.73 (95% CI: 2.34-3.20) vs 2.51 (95% CI: 2.15-2.93) vs 2.64 (95% CI: 2.26-3.10), respectively (top vs bottom fifth; fully adjusted models). Categorization by Lp(a) mass resulted in higher subdistribution HRs for uncorrected LDL-C and incident CHD at Lp(a) ≥90th percentile (4.38 [95% CI: 2.08-9.22]) vs 2.60 [95% CI: 2.21-3.07]) at Lp(a) <90th percentile (top vs bottom fifth; Pinteraction0.39). In contrast, apoB risk estimates were lower in subjects with higher Lp(a) mass (2.43 [95% CI: 1.34-4.40]) than in Lp(a) <90th percentile (3.34 [95% CI: 2.78-4.01]) (Pinteraction0.49). CONCLUSIONS: Correction of LDL-C for its Lp(a)-C content provided no meaningful information on CHD-risk estimation at the population level. Simple categorization of Lp(a) mass (≥/<90th percentile) influenced the association between LDL-C or apoB with future CHD mostly at higher Lp(a) levels.


Assuntos
Apolipoproteínas B , LDL-Colesterol , Doença das Coronárias , Lipoproteína(a) , Humanos , Lipoproteína(a)/sangue , LDL-Colesterol/sangue , Masculino , Feminino , Doença das Coronárias/sangue , Doença das Coronárias/epidemiologia , Pessoa de Meia-Idade , Apolipoproteínas B/sangue , Idoso , Adulto , Fatores de Risco , Medição de Risco/métodos , Incidência
2.
Elife ; 132024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39042440

RESUMO

Genetically encoded calcium indicators (GECIs) such as GCaMP are invaluable tools in neuroscience to monitor neuronal activity using optical imaging. The viral transduction of GECIs is commonly used to target expression to specific brain regions, can be conveniently used with any mouse strain of interest without the need for prior crossing with a GECI mouse line, and avoids potential hazards due to the chronic expression of GECIs during development. A key requirement for monitoring neuronal activity with an indicator is that the indicator itself minimally affects activity. Here, using common adeno-associated viral (AAV) transduction procedures, we describe spatially confined aberrant Ca2+ microwaves slowly travelling through the hippocampus following expression of GCaMP6, GCaMP7, or R-CaMP1.07 driven by the synapsin promoter with AAV-dependent gene transfer in a titre-dependent fashion. Ca2+ microwaves developed in hippocampal CA1 and CA3, but not dentate gyrus nor neocortex, were typically first observed at 4 wk after viral transduction, and persisted up to at least 8 wk. The phenomenon was robust and observed across laboratories with various experimenters and setups. Our results indicate that aberrant hippocampal Ca2+ microwaves depend on the promoter and viral titre of the GECI, density of expression, as well as the targeted brain region. We used an alternative viral transduction method of GCaMP which avoids this artefact. The results show that commonly used Ca2+-indicator AAV transduction procedures can produce artefactual Ca2+ responses. Our aim is to raise awareness in the field of these artefactual transduction-induced Ca2+ microwaves, and we provide a potential solution.


Assuntos
Cálcio , Dependovirus , Hipocampo , Sinapsinas , Animais , Dependovirus/genética , Sinapsinas/metabolismo , Sinapsinas/genética , Cálcio/metabolismo , Hipocampo/metabolismo , Camundongos , Vetores Genéticos , Transdução Genética , Regiões Promotoras Genéticas , Camundongos Endogâmicos C57BL , Masculino
3.
S Afr Med J ; 114(3b): e1365, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-39041445

RESUMO

In 2022, the Wits Transplant Unit performed 57 liver transplants: 33/57 adult (58%) and 24/57 paediatric (42%) recipients. At the beginning of 2022, 28 candidates were on the adult waitlist. Forty-six candidates were added to the waitlist during the year. Sixty-five percent of waitlisted candidate were transplanted. Adult candidates remained on the waitlist for longer than previous years, with 52% of them waitlisted for less than one year before undergoing liver transplantation. There was a decrease in adult pretransplant mortality to 9% in 2021 from 25% in 2020. The most common aetiology in waitlist candidates was alcoholic steatohepatitis (ASH)/non-alcoholic steatohepatitis (NASH) (36%) and in recipients cholestatic (primary sclerosing cholangitis (PSC) and primary biliary sclerosis (PBC)) (40%). Most adult recipients received a deceased donor graft (79%). Unadjusted recipient one- and three-year survivals were 75% (95% confidence interval (CI) 65 - 83) and 74% (95% CI 65 - 81), respectively. In the paediatric population, the most common aetiologies for both pretransplant candidates and transplant recipients remained cholestatic disease and acute liver failure. There was a decrease in paediatric pretransplant mortality from 27% in 2017 to 6% in 2021. Unlike the adult cohort, most paediatric recipients received a living donor graft (79%). Unadjusted one-year and three-year survival rates were 85% (95% CI 75 - 92) and 68% (95% CI 56 - 77), respectively.


Assuntos
Transplante de Fígado , Listas de Espera , Humanos , Listas de Espera/mortalidade , Adulto , Criança , África do Sul/epidemiologia , Masculino , Feminino , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Pré-Escolar , Taxa de Sobrevida , Lactente
4.
S Afr Med J ; 114(3b): e1367, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-39041443

RESUMO

BACKGROUND: In the paediatric liver transplant programme in Johannesburg, South Africa (SA), tacrolimus is the calcineurin inhibitor of choice, comprising an essential component of the immunosuppression regimen. It is characterised by a narrow therapeutic index and wide interpatient variability, necessitating therapeutic drug monitoring of whole-blood concentrations. Pharmacogenetic research, although not representative of SA population groups, suggests that single-nucleotide polymorphisms within the cytochrome P450 3A5 (CYP3A5) gene contribute to the variability in tacrolimus dosing requirements. The rs776746 polymorphism, CYP3A5*3, results in a splice defect and a non-functional enzyme. Clinically, to reach the same tacrolimus concentration-to-dose ratio (CDR), expressors (CYP3A5*1/*1 and *1/*3) require a higher tacrolimus dose than non-expressors (*3/*3). OBJECTIVES: To compare the pharmacokinetics of tacrolimus in paediatric liver transplant recipients with their donors' CYP3A5 genotypes, considering both donor and recipient characteristics. METHODS: Blood samples from 46 living liver donors were collected, their genomic DNA was extracted, and their CYP3A5 genotype was established (polymerase chain reaction and restriction fragment length polymorphism analysis, validated by Sanger sequencing). The relationship of donor and recipient characteristics with the mean tacrolimus CDR was analysed using a general linear model. Non- confounding significant variables were included in a multiple regression model. RESULTS: The study showed that all expressor donors genotyped as CYP3A5*1/*1 were of black African self-reported race and ethnicity. During the first 15 days post-transplant, we found that children who received grafts from donor CYP3A5 expressors (CYP3A5*1/*1 and *1/*3) had significantly lower mean tacrolimus CDRs compared with those who received grafts from donor CYP3A5 non-expressors (*3/*3); the recipients of CYP3A5 expressor grafts therefore require higher doses of oral tacrolimus to achieve the same therapeutic target range. In addition, graft-to-recipient weight ratio and the CYP3A5 donor genotypes were independent factors that significantly (p<0.05) affected mean tacrolimus CDRs in recipients. CONCLUSION: In this study, we showed that all CYP3A5*1 homozygote donors were of black African self-reported race and ethnicity, and tacrolimus CDRs in paediatric living-donor liver transplant recipients were significantly affected by donor graft size and donor CYP3A5 genotypes. Information from this study may inform the development of an Afrocentric tacrolimus precision-medicine algorithm to optimise recipient safety and graft outcomes.


Assuntos
Citocromo P-450 CYP3A , Genótipo , Imunossupressores , Transplante de Fígado , Polimorfismo de Nucleotídeo Único , Tacrolimo , Humanos , Tacrolimo/farmacocinética , Tacrolimo/administração & dosagem , Tacrolimo/uso terapêutico , Citocromo P-450 CYP3A/genética , África do Sul , Criança , Imunossupressores/farmacocinética , Imunossupressores/administração & dosagem , Imunossupressores/uso terapêutico , Masculino , Feminino , Pré-Escolar , Adolescente , Doadores Vivos , Lactente
5.
S Afr Med J ; 114(3b): e1366, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-39041444

RESUMO

BACKGROUND: South African transplant centres are faced with significant challenges in meeting the need for liver transplantation, owing to the low and ever-decreasing number of deceased-donor organs. To increase organ utility, deceased-donor split-liver transplant (DDSLT) and living-donor liver transplant (LDLT) programmes were initiated in the Wits Transplant Unit. OBJECTIVE: To evaluate outcomes of the LDLT and DDSLT programmes. METHODS: A retrospective analysis of de-identified recipient and donor variables from all adult and paediatric DDSLTs and LDLTs conducted between 2013 and 2021 was performed. Comparison of categorical study variables between graft types was done with the χ2 test. Continuous variables were compared by means of the independent samples t-test. Cox proportional hazards regression was performed to examine the effect of graft type on recipient and graft survival. All comparisons were made unadjusted, and adjusted for recipient age, recipient ethnicity, donor sex, and graft-weight-to-recipient-weight ratio (GWRWR) (for the paediatric cohort); and for donor age and GWRWR (for the adult cohort). RESULTS: A total of 181 paediatric and 48 adult liver transplants have been performed since the inception of the two programmes. Chronic liver failure, specifically intra- and extrahepatic cholestatic disease, was our main indication for liver transplantation in both cohorts. There were no significant differences between the DDSLTs and LDLTs in respect of pre- or post-discharge intervention, in-hospital mortality, length of stay, and recipient or graft survival within both the paediatric and adult groups. Our overall 1- and 3-year survival estimates (95% confidence intervals) were 77% (70% - 83%) and 71% (64% - 78%) for the paediatric cohort, and 77% (62% - 87%) and 66% (50% - 78%) for the adult cohort, respectively. CONCLUSION: The results of this study demonstrate comparable outcomes between DDSLT and LDLT, indicating that both methods are effective approaches to optimise organ utilisation for liver transplantation within our setting.


Assuntos
Sobrevivência de Enxerto , Transplante de Fígado , Doadores Vivos , Humanos , Transplante de Fígado/métodos , África do Sul , Estudos Retrospectivos , Feminino , Masculino , Adulto , Criança , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Pré-Escolar , Lactente , Complicações Pós-Operatórias/epidemiologia , Doadores de Tecidos
6.
S Afr Med J ; 114(3b): e1211, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-39041451

RESUMO

BACKGROUND: Liver transplantation is the definitive management for severe acute liver failure refractory to supportive management, and end- stage chronic liver failure. Owing to a shortage of deceased liver donors, South Africa requires innovative techniques to broaden the donor pool. OBJECTIVES: This study evaluated the outcomes of the Wits Transplant Unit ABO-incompatible liver transplant (ABOi-LT) programme. METHODS: This retrospective record review compared all adult and paediatric patients receiving ABO-compatible (ABOc) and ABO-incompatible (ABOi) liver transplants from January 2014 to December 2021 with a minimum one-year follow-up. Primary outcomes were recipient and graft survival and secondary outcomes included vascular, enteric and biliary complications, relook surgery, acute cellular rejection (ACR) and lenghth of hospital stay. Cox proportional hazards regression was performed to examine the effect of ABO-compatibility group on recipient and graft survival. The relationship between the ABO-compatibility group and categorical outcomes was assessed by binomial regression. RESULTS: During the study period, 532 liver transplants were performed; 44/532 (8%) were ABOi of which 14/44 (32%) were paediatric and 30/44 (68%) adult recipients. Within the pediatric group, the proportion of transplants performed for acute liver failure was significantly higher in the ABOi group (7/14; 50%) compared with the ABOc group (33/207; 16%) (p=0.005). Comparable recipient and graft survival estimates were noted: one-, three- and five-year recipient survival in the ABOi group was 77% (95% confidence interval (CI) 44 - 92), 58% (95% CI 17 - 84) and 58% (95% CI 17 - 84) respectively. There were significantly increased relative risks of relook surgery for the ABOi group compared with the ABOc group, both overall (relative risk (RR) 1.74; 95% CI 1.10 - 2.75) and at 90 days (RR 2.28; 95% CI 1.27 - 4.11); and also, for pre-discharge bloodstream infection (BSI), (RR 1.84; 95% CI 1.11 - 3.06). In adults, there were significantly more acute indications for liver transplantation in the ABOi (10/30; 33%) compared with the ABOc group (26/281; 9%) (p=0.0007) with the most common cause being drug or toxin ingestion (16/36; 44%). For the ABOi group, recipient survival estimates (95% CI) at 1, 3 and 5 years were 71% (50 - 84), 63% (41 - 78) and 58% (37 - 75) which, as noted with complication rates, were similar between ABO groups. CONCLUSION: This study confirms ABOi-LT as a feasible option to increase the liver donor pool in this organ-depleted setting as recipient survival and complication rates were similar between ABO-compatibility groups.


Assuntos
Sistema ABO de Grupos Sanguíneos , Incompatibilidade de Grupos Sanguíneos , Sobrevivência de Enxerto , Transplante de Fígado , Humanos , Transplante de Fígado/métodos , África do Sul , Estudos Retrospectivos , Feminino , Masculino , Sistema ABO de Grupos Sanguíneos/imunologia , Adulto , Pessoa de Meia-Idade , Criança , Rejeição de Enxerto , Doença Hepática Terminal/cirurgia , Adolescente , Pré-Escolar , Obtenção de Tecidos e Órgãos/métodos , Adulto Jovem
7.
S Afr Med J ; 114(3b): e1190, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-39041452

RESUMO

BACKGROUND: The Wits Transplant Unit performed its first paediatric liver transplant in 2005. Initial experiences from the unit were published in 2012 and 2014. Since then, significant progress has been made in capacity-building the unit, improving outcomes and enhancing service delivery. This paper presents a broad overview and update of the unit's 17-year experience.   Methods: We conducted a retrospective review of all paediatric liver transplants performed in Johannesburg from 1 January 2005 to 31 December 2021 with a minimum one-year follow-up. Data were accessed from the Wits Donald Gordon Medical Centre Paediatric Liver Transplant Research Database (University of the Witwatersrand Human Research Ethics approval: M190749). The following data were collected: donor and recipient sociodemographic and clinical characteristics, details of transplant procedures, donor grafts and recipient outcomes (post-operative complications, graft and recipient survival).   Results: A total of 270 transplants were performed during the review period. Two thirds of recipients (n=180, 67%) were younger than 5 years at time of transplant and half (n=135, 50%) received a living donor graft. The most common indication for liver transplant was biliary atresia, followed by acute liver failure. Unadjusted recipient survival was 80% (95% CI: 75-85%) at one year, and 68% (95% CI: 59-75%) at five years. Waiting list mortality decreased from 27.3% in 2017 to 5.9% in 2021. One hundred and fifty-four (57.0%) recipients experienced at least one type of intervention requiring surgical complication - the most common being biliary in nature (n = 91; 33.7%).   Conclusion: Over last seventeen years, a sustainable paediatric liver transplantation service has been established in Johannesburg. Living donor, split and ABO incompatible liver transplants have been incorporated in response to the severe organ shortage in South Africa. However, our outcomes can be improved. Additionally, a national transplant initiative to coordinate timeous referrals and expand access to liver transplantation for children with severe acute and chronic liver failure is advised.


Assuntos
Transplante de Fígado , Humanos , África do Sul , Estudos Retrospectivos , Criança , Pré-Escolar , Masculino , Feminino , Adolescente , Lactente , Sobrevivência de Enxerto , Doadores Vivos , Complicações Pós-Operatórias/epidemiologia , Atresia Biliar/cirurgia
8.
Genome Biol ; 25(1): 181, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38978088

RESUMO

Single-cell multiomic analysis of the epigenome, transcriptome, and proteome allows for comprehensive characterization of the molecular circuitry that underpins cell identity and state. However, the holistic interpretation of such datasets presents a challenge given a paucity of approaches for systematic, joint evaluation of different modalities. Here, we present Panpipes, a set of computational workflows designed to automate multimodal single-cell and spatial transcriptomic analyses by incorporating widely-used Python-based tools to perform quality control, preprocessing, integration, clustering, and reference mapping at scale. Panpipes allows reliable and customizable analysis and evaluation of individual and integrated modalities, thereby empowering decision-making before downstream investigations.


Assuntos
Análise de Célula Única , Software , Transcriptoma , Análise de Célula Única/métodos , Perfilação da Expressão Gênica/métodos , Humanos , Fluxo de Trabalho
9.
Viruses ; 16(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38932176

RESUMO

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages and presents a novel, efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers to enrich tobamoviruses, from the search for the causative agents of mosaic diseases in plants to their increasing recognition as versatile nanocarriers in biomedical and engineering applications. The best practices and rarely applied options for the serial processing steps required for successful isolation of tobamoviruses are then reviewed. Adaptations for distinct particle species, pitfalls, and 'forgotten' or underrepresented technologies are considered as well. The article is topped off with our own development of a method for virion preparation, rooted in historical protocols. It combines selective re-solubilization of polyethylene glycol (PEG) virion raw precipitates with density step gradient centrifugation in biocompatible iodixanol formulations, yielding ready-to-use particle suspensions. This newly established protocol and some considerations for perhaps worthwhile further developments could serve as putative stepping stones towards preparation procedures appropriate for routine practical uses of these multivalent soft-matter nanorods.


Assuntos
Tobamovirus , Vírion , Vírion/isolamento & purificação , Tobamovirus/genética , Tobamovirus/isolamento & purificação , Doenças das Plantas/virologia , Virologia/métodos , Centrifugação com Gradiente de Concentração/métodos
10.
Lipids Health Dis ; 23(1): 197, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926753

RESUMO

BACKGROUND: Lipids, including phospholipids and bile acids, exert various signaling effects and are thought to contribute to the development of coronary artery disease (CAD). Here, we aimed to compare lipidomic and bile acid profiles in the blood of patients with and without CAD stratified by sex. METHODS: From 2015 to 2022, 3,012 patients who underwent coronary angiography were recruited in the INTERCATH cohort. From the overall cohort, subgroups were defined using patient characteristics such as CAD vs. no CAD, 1st vs. 3rd tertile of LDL-c, and female vs. male sex. Hereafter, a matching algorithm based on age, BMI, hypertension status, diabetes mellitus status, smoking status, the Mediterranean diet score, and the intake of statins, triglycerides, HDL-c and hs-CRP in a 1:1 ratio was implemented. Lipidomic analyses of stored blood samples using the Lipidyzer platform (SCIEX) and bile acid analysis using liquid chromatography with tandem mass spectrometry (LC‒MS/MS) were carried out. RESULTS: A total of 177 matched individuals were analyzed; the median ages were 73.5 years (25th and 75th percentile: 64.1, 78.2) and 71.9 years (65.7, 77.2) for females and males with CAD, respectively, and 67.6 years (58.3, 75.3) and 69.2 years (59.8, 76.8) for females and males without CAD, respectively. Further baseline characteristics, including cardiovascular risk factors, were balanced between the groups. Women with CAD had decreased levels of phosphatidylcholine and diacylglycerol, while no differences in bile acid profiles were detected in comparison to those of female patients without CAD. In contrast, in male patients with CAD, decreased concentrations of the secondary bile acid species glycolithocholic and lithocholic acid, as well as altered levels of specific lipids, were detected compared to those in males without CAD. Notably, male patients with low LDL-c and CAD had significantly greater concentrations of various phospholipid species, particularly plasmalogens, compared to those in high LDL-c subgroup. CONCLUSIONS: We present hypothesis-generating data on sex-specific lipidomic patterns and bile acid profiles in CAD patients. The data suggest that altered lipid and bile acid composition might contribute to CAD development and/or progression, helping to understand the different disease trajectories of CAD in women and men. REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT04936438 , Unique identifier: NCT04936438.


Assuntos
Ácidos e Sais Biliares , Doença da Artéria Coronariana , Lipidômica , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácidos e Sais Biliares/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Doença da Artéria Coronariana/sangue , Caracteres Sexuais , Fatores Sexuais , Espectrometria de Massas em Tandem , Triglicerídeos/sangue , Estudos de Coortes
11.
Genome Med ; 16(1): 80, 2024 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862979

RESUMO

The study of immunology, traditionally reliant on proteomics to evaluate individual immune cells, has been revolutionized by single-cell RNA sequencing. Computational immunologists play a crucial role in analysing these datasets, moving beyond traditional protein marker identification to encompass a more detailed view of cellular phenotypes and their functional roles. Recent technological advancements allow the simultaneous measurements of multiple cellular components-transcriptome, proteome, chromatin, epigenetic modifications and metabolites-within single cells, including in spatial contexts within tissues. This has led to the generation of complex multiscale datasets that can include multimodal measurements from the same cells or a mix of paired and unpaired modalities. Modern machine learning (ML) techniques allow for the integration of multiple "omics" data without the need for extensive independent modelling of each modality. This review focuses on recent advancements in ML integrative approaches applied to immunological studies. We highlight the importance of these methods in creating a unified representation of multiscale data collections, particularly for single-cell and spatial profiling technologies. Finally, we discuss the challenges of these holistic approaches and how they will be instrumental in the development of a common coordinate framework for multiscale studies, thereby accelerating research and enabling discoveries in the computational immunology field.


Assuntos
Biologia Computacional , Aprendizado de Máquina , Humanos , Biologia Computacional/métodos , Análise de Célula Única/métodos , Alergia e Imunologia , Animais , Imunoinformática
12.
Bioinformatics ; 40(Supplement_1): i548-i557, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940138

RESUMO

SUMMARY: Spatial omics technologies are increasingly leveraged to characterize how disease disrupts tissue organization and cellular niches. While multiple methods to analyze spatial variation within a sample have been published, statistical and computational approaches to compare cell spatial organization across samples or conditions are mostly lacking. We present GraphCompass, a comprehensive set of omics-adapted graph analysis methods to quantitatively evaluate and compare the spatial arrangement of cells in samples representing diverse biological conditions. GraphCompass builds upon the Squidpy spatial omics toolbox and encompasses various statistical approaches to perform cross-condition analyses at the level of individual cell types, niches, and samples. Additionally, GraphCompass provides custom visualization functions that enable effective communication of results. We demonstrate how GraphCompass can be used to address key biological questions, such as how cellular organization and tissue architecture differ across various disease states and which spatial patterns correlate with a given pathological condition. GraphCompass can be applied to various popular omics techniques, including, but not limited to, spatial proteomics (e.g. MIBI-TOF), spot-based transcriptomics (e.g. 10× Genomics Visium), and single-cell resolved transcriptomics (e.g. Stereo-seq). In this work, we showcase the capabilities of GraphCompass through its application to three different studies that may also serve as benchmark datasets for further method development. With its easy-to-use implementation, extensive documentation, and comprehensive tutorials, GraphCompass is accessible to biologists with varying levels of computational expertise. By facilitating comparative analyses of cell spatial organization, GraphCompass promises to be a valuable asset in advancing our understanding of tissue function in health and disease. .


Assuntos
Software , Humanos , Proteômica/métodos , Biologia Computacional/métodos , Genômica/métodos , Animais , Transcriptoma , Análise de Célula Única/métodos
13.
Artigo em Alemão | MEDLINE | ID: mdl-38904775

RESUMO

The prevalence of cardiovascular diseases increases with age. Common symptoms such as dyspnea, chest pain, dizziness, or syncope can impact driving fitness. Due to a growing number of private drivers aged 65 and older and an increasing prevalence of cardiovascular diseases, questions regarding driving fitness restrictions for cardiological patients are gaining prominence in clinical settings. This article aims to summarize current recommendations for driving fitness in the context of cardiovascular diseases. The basis for the guidelines includes the Driving License Ordinance, the expert assessment guidelines of the Federal Highway Research Institute, and the guidelines of the German Society of Cardiology on driving fitness. Original literature on this topic is limited.Emphasizing an individualized assessment, clear guidelines for driving fitness in cardiac diseases or their symptoms and treatments are formulated. Regardless of the cardiac condition, the symptoms and likelihood of sudden loss of consciousness play a leading role in driving fitness assessment. Resulting impairments can range from a few weeks to a complete revocation of driving fitness. Regular examinations and differentiated assessments by medical professionals are prerequisites for maintaining driving fitness.The driving fitness of older private drivers is a significant and practical topic in cardiology. Current guidelines support the treating physicians in providing appropriate recommendations.

14.
Cell ; 187(10): 2343-2358, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38729109

RESUMO

As the number of single-cell datasets continues to grow rapidly, workflows that map new data to well-curated reference atlases offer enormous promise for the biological community. In this perspective, we discuss key computational challenges and opportunities for single-cell reference-mapping algorithms. We discuss how mapping algorithms will enable the integration of diverse datasets across disease states, molecular modalities, genetic perturbations, and diverse species and will eventually replace manual and laborious unsupervised clustering pipelines.


Assuntos
Algoritmos , Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Biologia Computacional/métodos , Análise de Dados , Animais , Análise por Conglomerados
15.
Nat Comput Sci ; 4(5): 367-378, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38730184

RESUMO

Large language models have greatly enhanced our ability to understand biology and chemistry, yet robust methods for structure-based drug discovery, quantum chemistry and structural biology are still sparse. Precise biomolecule-ligand interaction datasets are urgently needed for large language models. To address this, we present MISATO, a dataset that combines quantum mechanical properties of small molecules and associated molecular dynamics simulations of ~20,000 experimental protein-ligand complexes with extensive validation of experimental data. Starting from the existing experimental structures, semi-empirical quantum mechanics was used to systematically refine these structures. A large collection of molecular dynamics traces of protein-ligand complexes in explicit water is included, accumulating over 170 µs. We give examples of machine learning (ML) baseline models proving an improvement of accuracy by employing our data. An easy entry point for ML experts is provided to enable the next generation of drug discovery artificial intelligence models.


Assuntos
Descoberta de Drogas , Aprendizado de Máquina , Simulação de Dinâmica Molecular , Proteínas , Ligantes , Descoberta de Drogas/métodos , Proteínas/química , Proteínas/metabolismo , Teoria Quântica
16.
Plants (Basel) ; 13(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38732473

RESUMO

Green algae blooms of the genus Ulva are occurring globally and are primarily attributed to anthropogenic factors. At Los Tubos beach in Algarrobo Bay along the central Chilean coast, there have been blooms of these algae that persist almost year-round over the past 20 years, leading to environmental, economic, and social issues that affect the local government and communities. The objective of this study was to characterize the species that form these green tides based on a combination of ecological, morpho-anatomical, and molecular information. For this purpose, seasonal surveys of beached algal fronds were conducted between 2021 and 2022. Subsequently, the sampled algae were analyzed morphologically and phylogenetically using the molecular markers ITS1 and tufA, allowing for the identification of at least five taxa. Of these five taxa, three (U. stenophylloides, U. uncialis, U. australis) have laminar, foliose, and distromatic morphology, while the other two (U. compressa, U. aragoensis) have tubular, filamentous, and monostromatic fronds. Intertidal surveys showed that U. stenophylloides showed the highest relative coverage throughout the seasons and all intertidal levels, followed by U. uncialis. Therefore, we can establish that the green tides on the coast of Algarrobo in Chile are multispecific, with differences in relative abundance during different seasons and across the intertidal zone, opening opportunities for diverse future studies, ranging from ecology to algal biotechnology.

17.
Nat Commun ; 15(1): 4413, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38782910

RESUMO

In Josephson diodes the asymmetry between positive and negative current branch of the current-phase relation leads to a polarity-dependent critical current and Josephson inductance. The supercurrent nonreciprocity can be described as a consequence of the anomalous Josephson effect -a φ0-shift of the current-phase relation- in multichannel ballistic junctions with strong spin-orbit interaction. In this work, we simultaneously investigate φ0-shift and supercurrent diode efficiency on the same Josephson junction by means of a superconducting quantum interferometer. By electrostatic gating, we reveal a direct link between φ0-shift and diode effect. Our findings show that spin-orbit interaction in combination with a Zeeman field plays an important role in determining the magnetochiral anisotropy and the supercurrent diode effect.

18.
Genome Biol ; 25(1): 109, 2024 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671451

RESUMO

Single-cell multiplexing techniques (cell hashing and genetic multiplexing) combine multiple samples, optimizing sample processing and reducing costs. Cell hashing conjugates antibody-tags or chemical-oligonucleotides to cell membranes, while genetic multiplexing allows to mix genetically diverse samples and relies on aggregation of RNA reads at known genomic coordinates. We develop hadge (hashing deconvolution combined with genotype information), a Nextflow pipeline that combines 12 methods to perform both hashing- and genotype-based deconvolution. We propose a joint deconvolution strategy combining best-performing methods and demonstrate how this approach leads to the recovery of previously discarded cells in a nuclei hashing of fresh-frozen brain tissue.


Assuntos
Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Encéfalo/metabolismo , Encéfalo/citologia , Software , Genótipo
19.
Nat Commun ; 15(1): 2866, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38570482

RESUMO

Traumatic brain injury leads to a highly orchestrated immune- and glial cell response partially responsible for long-lasting disability and the development of secondary neurodegenerative diseases. A holistic understanding of the mechanisms controlling the responses of specific cell types and their crosstalk is required to develop an efficient strategy for better regeneration. Here, we combine spatial and single-cell transcriptomics to chart the transcriptomic signature of the injured male murine cerebral cortex, and identify specific states of different glial cells contributing to this signature. Interestingly, distinct glial cells share a large fraction of injury-regulated genes, including inflammatory programs downstream of the innate immune-associated pathways Cxcr3 and Tlr1/2. Systemic manipulation of these pathways decreases the reactivity state of glial cells associated with poor regeneration. The functional relevance of the discovered shared signature of glial cells highlights the importance of our resource enabling comprehensive analysis of early events after brain injury.


Assuntos
Lesões Encefálicas , Ferimentos Perfurantes , Animais , Camundongos , Masculino , Proteína Glial Fibrilar Ácida/metabolismo , Neuroglia/metabolismo , Lesões Encefálicas/metabolismo , Córtex Cerebral/metabolismo , Ferimentos Perfurantes/complicações , Ferimentos Perfurantes/metabolismo
20.
Res Sq ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38645152

RESUMO

With the growing number of single-cell analysis tools, benchmarks are increasingly important to guide analysis and method development. However, a lack of standardisation and extensibility in current benchmarks limits their usability, longevity, and relevance to the community. We present Open Problems, a living, extensible, community-guided benchmarking platform including 10 current single-cell tasks that we envision will raise standards for the selection, evaluation, and development of methods in single-cell analysis.

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