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1.
Bioinformatics ; 40(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38390963

RESUMEN

MOTIVATION: A patient's disease phenotype can be driven and determined by specific groups of cells whose marker genes are either unknown or can only be detected at late-stage using conventional bulk assays such as RNA-Seq technology. Recent advances in single-cell RNA sequencing (scRNA-seq) enable gene expression profiling in cell-level resolution, and therefore have the potential to identify those cells driving the disease phenotype even while the number of these cells is small. However, most existing methods rely heavily on accurate cell type detection, and the number of available annotated samples is usually too small for training deep learning predictive models. RESULTS: Here, we propose the method ScRAT for phenotype prediction using scRNA-seq data. To train ScRAT with a limited number of samples of different phenotypes, such as coronavirus disease (COVID) and non-COVID, ScRAT first applies a mixup module to increase the number of training samples. A multi-head attention mechanism is employed to learn the most informative cells for each phenotype without relying on a given cell type annotation. Using three public COVID datasets, we show that ScRAT outperforms other phenotype prediction methods. The performance edge of ScRAT over its competitors increases as the number of training samples decreases, indicating the efficacy of our sample mixup. Critical cell types detected based on high-attention cells also support novel findings in the original papers and the recent literature. This suggests that ScRAT overcomes the challenge of missing marker genes and limited sample number with great potential revealing novel molecular mechanisms and/or therapies. AVAILABILITY AND IMPLEMENTATION: The code of our proposed method ScRAT is published at https://github.com/yuzhenmao/ScRAT.


Asunto(s)
Análisis de la Célula Individual , Análisis de Expresión Génica de una Sola Célula , Humanos , Análisis de la Célula Individual/métodos , RNA-Seq , Perfilación de la Expresión Génica , Redes Neurales de la Computación , Fenotipo , Análisis de Secuencia de ARN , Análisis por Conglomerados
3.
Proc Natl Acad Sci U S A ; 119(18): e2116507119, 2022 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-35486692

RESUMEN

The noradrenergic locus coeruleus (LC) is a controller of brain and behavioral states. Activating LC neurons en masse by electrical or optogenetic stimulation promotes a stereotypical "activated" cortical state of high-frequency oscillations. However, it has been recently reported that spontaneous activity of LC cell pairs has sparse yet structured time-averaged cross-correlations, which is unlike the highly synchronous neuronal activity evoked by stimulation. Therefore, LC population activity could consist of distinct multicell ensembles each with unique temporal evolution of activity. We used nonnegative matrix factorization (NMF) to analyze large populations of simultaneously recorded LC single units in the rat LC. NMF identified ensembles of spontaneously coactive LC neurons and their activation time courses. Since LC neurons selectively project to specific forebrain regions, we hypothesized that distinct ensembles activate during different cortical states. To test this hypothesis, we calculated band-limited power and spectrograms of local field potentials in cortical area 24a aligned to spontaneous activations of distinct LC ensembles. A diversity of state modulations occurred around activation of different LC ensembles, including a typical activated state with increased high-frequency power as well as other states including decreased high-frequency power. Thus­in contrast to the stereotypical activated brain state evoked by en masse LC stimulation­spontaneous activation of distinct LC ensembles is associated with a multitude of cortical states.


Asunto(s)
Neuronas Adrenérgicas , Locus Coeruleus , Neuronas Adrenérgicas/fisiología , Nivel de Alerta/fisiología , Locus Coeruleus/fisiología , Norepinefrina , Optogenética
4.
J Neurophysiol ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38842506

RESUMEN

Our understanding of human brain function can be greatly aided by studying analogous brain structures in other organisms. One brain structure with neurochemical and anatomical homology throughout vertebrate species is the locus coeruleus (LC), a small collection of norepinephrine (NE) containing neurons in the brainstem that project throughout the central nervous system. The LC is involved in nearly every aspect of brain function, including arousal and learning, which has been extensively examined in rats and non-human primates using single unit recordings. Recent work has expanded into putative LC single unit electrophysiological recordings in a non-model species, the zebra finch. Given the importance of correctly identifying analogous structures as research efforts expand to other vertebrates, we suggest adoption of consensus anatomical and electrophysiological guidelines for identifying LC neurons across species when evaluating brainstem single unit spiking or calcium imaging. Such consensus criteria will allow for confident cross-species understanding of the roles of the LC in brain function and behavior.

5.
Lancet ; 402(10409): 1241-1250, 2023 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-37805215

RESUMEN

BACKGROUND: In sub-Saharan Africa, health-care provision for chronic conditions is fragmented. The aim of this study was to determine whether integrated management of HIV, diabetes, and hypertension led to improved rates of retention in care for people with diabetes or hypertension without adversely affecting rates of HIV viral suppression among people with HIV when compared to standard vertical care in medium and large health facilities in Uganda and Tanzania. METHODS: In INTE-AFRICA, a pragmatic cluster-randomised, controlled trial, we randomly allocated primary health-care facilities in Uganda and Tanzania to provide either integrated care or standard care for HIV, diabetes, and hypertension. Random allocation (1:1) was stratified by location, infrastructure level, and by country, with a permuted block randomisation method. In the integrated care group, participants with HIV, diabetes, or hypertension were managed by the same health-care workers, used the same pharmacy, had similarly designed medical records, shared the same registration and waiting areas, and had an integrated laboratory service. In the standard care group, these services were delivered vertically for each condition. Patients were eligible to join the trial if they were living with confirmed HIV, diabetes, or hypertension, were aged 18 years or older, were living within the catchment population area of the health facility, and were likely to remain in the catchment population for 6 months. The coprimary outcomes, retention in care (attending a clinic within the last 6 months of study follow-up) for participants with either diabetes or hypertension (tested for superiority) and plasma viral load suppression for those with HIV (>1000 copies per mL; tested for non-inferiority, 10% margin), were analysed using generalised estimating equations in the intention-to-treat population. This trial is registered with ISCRTN 43896688. FINDINGS: Between June 30, 2020, and April 1, 2021 we randomly allocated 32 health facilities (17 in Uganda and 15 in Tanzania) with 7028 eligible participants to the integrated care or the standard care groups. Among participants with diabetes, hypertension, or both, 2298 (75·8%) of 3032 were female and 734 (24·2%) of 3032 were male. Of participants with HIV alone, 2365 (70·3%) of 3365 were female and 1000 (29·7%) of 3365 were male. Follow-up lasted for 12 months. Among participants with diabetes, hypertension, or both, the proportion alive and retained in care at study end was 1254 (89·0%) of 1409 in integrated care and 1457 (89·8%) of 1623 in standard care. The risk differences were -0·65% (95% CI -5·76 to 4·46; p=0·80) unadjusted and -0·60% (-5·46 to 4·26; p=0·81) adjusted. Among participants with HIV, the proportion who had a plasma viral load of less than 1000 copies per mL was 1412 (97·0%) of 1456 in integrated care and 1451 (97·3%) of 1491 in standard care. The differences were -0·37% (one-sided 95% CI -1·99 to 1·26; pnon-inferiority<0·0001 unadjusted) and -0·36% (-1·99 to 1·28; pnon-inferiority<0·0001 adjusted). INTERPRETATION: In sub-Saharan Africa, integrated chronic care services could achieve a high standard of care for people with diabetes or hypertension without adversely affecting outcomes for people with HIV. FUNDING: European Union Horizon 2020 and Global Alliance for Chronic Diseases.


Asunto(s)
Fármacos Anti-VIH , Diabetes Mellitus , Infecciones por VIH , Hipertensión , Femenino , Humanos , Masculino , Fármacos Anti-VIH/uso terapéutico , Diabetes Mellitus/terapia , Diabetes Mellitus/tratamiento farmacológico , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Infecciones por VIH/terapia , Hipertensión/terapia , Hipertensión/tratamiento farmacológico , Tanzanía/epidemiología
6.
Gynecol Oncol ; 188: 162-168, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38970843

RESUMEN

OBJECTIVE: Dedifferentiated endometrial carcinoma (DDEC) characterized by SWItch/Sucrose Non-Fermentable (SWI/SNF) complex inactivation is a highly aggressive type of endometrial cancer without effective systemic therapy options. Its uncommon nature and aggressive disease trajectory pose significant challenges for therapeutic progress. To address this obstacle, we focused on developing preclinical models tailored to this tumor type and established patient tumor-derived three-dimensional (3D) spheroid models of DDEC. METHODS: High-throughput drug repurposing screens were performed on in vitro 3D spheroid models of DDEC cell lines (SMARCA4-inactivated DDEC-1 and ARID1A/ARID1B co-inactivated DDEC-2). The dose-response relationships of the identified candidate drugs were evaluated in vitro, followed by in vivo evaluation using xenograft models of DDEC-1 and DDEC-2. RESULTS: Drug screen in 3D models identified multiple cardiac glycosides including digoxin and digitoxin as candidate drugs in both DDEC-1 and DDEC-2. Subsequent in vitro dose-response analyses confirmed the inhibitory activity of digoxin and digitoxin with both drugs showing lower IC50 in DDEC cells compared to non-DDEC endometrial cancer cells. In in vivo xenograft models, digoxin significantly suppressed the growth of DDEC tumors at clinically relevant serum concentrations. CONCLUSION: Using biologically precise preclinical models of DDEC derived from patient tumor samples, our study identified digoxin as an effective drug in suppressing DDEC tumor growth. These findings provide compelling preclinical evidence for the use of digoxin as systemic therapy for SWI/SNF-inactivated DDEC, which may also be applicable to other SWI/SNF-inactivated tumor types.

7.
Cereb Cortex ; 33(12): 7952-7959, 2023 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-36958811

RESUMEN

The mind affects the body via central nervous system (CNS) control of the autonomic nervous system (ANS). In humans, one striking illustration of the "mind-body" connection is that illusions, subjectively perceived as bright, drive pupil constriction. The CNS network driving this pupil response is unknown and requires an animal model for investigation. However, the pupil response to this illusion has long been thought to occur only in humans. Here, we report that the same brightness illusion that evokes pupil constriction in humans also does so in rats. We surveyed the role of most of rat cortex in this "mind-body" connection by recording cortex-wide EEG. These recordings revealed that, compared to a luminance-matched control stimulus, the illusion of brightness for a specific stimulus color and size, evoked a larger response in primary visual cortex (V1) and not in secondary visual, parietal, or frontal cortex. The response preceded pupil constriction suggesting a potential causal role of V1 on the pupil. Our results provide evidence that this "mind-body" connection is not confined to humans and that V1 may be part of a mammalian CNS network for bodily reactions to illusions.


Asunto(s)
Ilusiones , Pupila , Humanos , Animales , Ratas , Pupila/fisiología , Ilusiones/fisiología , Constricción , Corteza Visual Primaria , Visión Ocular , Percepción Visual/fisiología , Mamíferos
8.
Am J Hum Genet ; 106(6): 885-892, 2020 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-32413284

RESUMEN

Leveraging high-dimensional molecular datasets can help us develop mechanistic insight into associations between genetic variants and complex traits. In this study, we integrated human proteome data derived from brain tissue to evaluate whether targeted proteins putatively mediate the effects of genetic variants on seven neurological phenotypes (Alzheimer disease, amyotrophic lateral sclerosis, depression, insomnia, intelligence, neuroticism, and schizophrenia). Applying the principles of Mendelian randomization (MR) systematically across the genome highlighted 43 effects between genetically predicted proteins derived from the dorsolateral prefrontal cortex and these outcomes. Furthermore, genetic colocalization provided evidence that the same causal variant at 12 of these loci was responsible for variation in both protein and neurological phenotype. This included genes such as DCC, which encodes the netrin-1 receptor and has an important role in the development of the nervous system (p = 4.29 × 10-11 with neuroticism), as well as SARM1, which has been previously implicated in axonal degeneration (p = 1.76 × 10-08 with amyotrophic lateral sclerosis). We additionally conducted a phenome-wide MR study for each of these 12 genes to assess potential pleiotropic effects on 700 complex traits and diseases. Our findings suggest that genes such as SNX32, which was initially associated with increased risk of Alzheimer disease, may potentially influence other complex traits in the opposite direction. In contrast, genes such as CTSH (which was also associated with Alzheimer disease) and SARM1 may make worthwhile therapeutic targets because they did not have genetically predicted effects on any of the other phenotypes after correcting for multiple testing.


Asunto(s)
Encéfalo/metabolismo , Variación Genética/genética , Enfermedades del Sistema Nervioso/genética , Fenómica , Proteoma/genética , Proteómica , Enfermedad de Alzheimer/genética , Esclerosis Amiotrófica Lateral/genética , Proteínas del Dominio Armadillo/genética , Proteínas Portadoras/genética , Catepsina H/genética , Proteínas del Citoesqueleto/genética , Depresión/genética , Estudio de Asociación del Genoma Completo , Humanos , Inteligencia/genética , Enfermedades del Sistema Nervioso/metabolismo , Neuroticismo , Proteínas Nucleares/genética , Fenotipo , Proteoma/metabolismo , Esquizofrenia/genética , Trastornos del Inicio y del Mantenimiento del Sueño/genética , Nexinas de Clasificación/genética
9.
Gynecol Oncol ; 176: 162-172, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37556934

RESUMEN

OBJECTIVE: Dedifferentiated endometrial cancer (DDEC) is an uncommon and clinically highly aggressive subtype of endometrial cancer characterized by genomic inactivation of SWItch/Sucrose Non-Fermentable (SWI/SNF) complex protein. It responds poorly to conventional systemic treatment and its rapidly progressive clinical course limits the therapeutic windows to trial additional lines of therapies. This underscores a pressing need for biologically accurate preclinical tumor models to accelerate therapeutic development. METHODS: DDEC tumor from surgical samples were implanted into immunocompromised mice for patient-derived xenograft (PDX) and cell line development. The histologic, immunophenotypic, genetic and epigenetic features of the patient tumors and the established PDX models were characterized. The SMARCA4-deficienct DDEC model was evaluated for its sensitivity toward a KDM6A/B inhibitor (GSK-J4) that was previously reported to be effective therapy for other SMARCA4-deficient cancer types. RESULTS: All three DDEC models exhibited rapid growth in vitro and in vivo, with two PDX models showing spontaneous development of metastases in vivo. The PDX tumors maintained the same undifferentiated histology and immunophenotype, and exhibited identical genomic and methylation profiles as seen in the respective parental tumors, including a mismatch repair (MMR)-deficient DDEC with genomic inactivation of SMARCA4, and two MMR-deficient DDECs with genomic inactivation of both ARID1A and ARID1B. Although the SMARCA4-deficient cell line showed low micromolecular sensitivity to GSK-J4, no significant tumor growth inhibition was observed in the corresponding PDX model. CONCLUSIONS: These established patient tumor-derived models accurately depict DDEC and represent valuable preclinical tools to gain therapeutic insights into this aggressive tumor type.


Asunto(s)
Neoplasias Encefálicas , Neoplasias Colorrectales , Neoplasias Endometriales , Femenino , Humanos , Animales , Ratones , Neoplasias Endometriales/tratamiento farmacológico , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Diferenciación Celular , Biomarcadores de Tumor/genética , ADN Helicasas , Proteínas Nucleares/genética , Factores de Transcripción/genética , Proteínas de Unión al ADN/genética
10.
AIDS Care ; 35(9): 1291-1298, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37170392

RESUMEN

Intimate partner violence (IPV) has been associated with delays throughout the HIV care continuum. This study explored prospective associations between experiences of past-year IPV and two HIV care outcomes in the context of current universal test and treat guidelines using two consecutive rounds of an ongoing HIV surveillance study conducted in the Rakai region of Uganda. Longitudinal logistic regression models examined associations between IPV, use of antiretroviral therapy (ART) and viral load suppression (VS), adjusting for outcome variables at baseline. To address differences in ART retention by IPV, propensity scores were used to create inverse-probability-of-treatment-and-censoring-weighted (IPTCW) models. At baseline, of 1923 women with HIV (WWH), 34.6%, 26.5%, 13.5% reported past-year verbal, physical and sexual IPV; a lower proportion of persons who experienced physical IPV (79.4%) were VS than those who did not (84.3%; p = 0.01). The proportion VS at baseline also significantly differed by exposure to verbal IPV (p = 0.03). However, in adjusted longitudinal models, IPV was not associated with lower odds of ART use or VS at follow-up. Among WWH in the Rakai region, IPV does not appear to be a barrier to subsequent ART use or VS. However, given the prevalence of IPV in this population, interventions are needed.


Asunto(s)
Infecciones por VIH , Violencia de Pareja , Humanos , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Uganda/epidemiología , Conducta Sexual , Prevalencia , Parejas Sexuales , Factores de Riesgo
11.
Health Res Policy Syst ; 21(1): 32, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37127604

RESUMEN

BACKGROUND: Recommendations for research partnerships between low- and middle-income countries (LMICs) and high-income countries (HICs) stress the importance of equity within the collaboration. However, there is limited knowledge of the practical challenges and successes involved in establishing equitable research practices. This study describes the results of a pilot survey assessing key issues on LMIC/HIC partnership equity within HIV/AIDS research collaborations and compares perspectives of these issues between LMIC- and HIC-based investigators. METHODS: Survey participants were selected using clustered, random sampling and snowball sampling. Responses were compared between LMIC and HIC respondents using standard descriptive statistics. Qualitative respondent feedback was analyzed using a combination of exploratory and confirmatory thematic analysis. RESULTS: The majority of categories within four themes (research interests and resources; leadership, trust, and communication; cultural and ethical competence; representation and benefits) demonstrated relative consensus between LMIC and HIC respondents except for 'lack of trust within the partnership' which was rated as a more pronounced challenge by LMIC respondents. However, subcategories within some of the themes had significant differences between respondent groups including: equitable setting of the research agenda, compromise within a partnership, the role of regulatory bodies in monitoring partnerships for equity, and post-study access to research technology. CONCLUSIONS: These efforts serve as a proof-of-concept survey characterizing contemporary issues around international research partnership equity. The frequency and severity of specific equity issues can be assessed, highlighting similarities versus differences in experiences between LMIC and HIC partners as potential targets for further discussion and evaluation.


Asunto(s)
Países en Desarrollo , Infecciones por VIH , Humanos , Países Desarrollados , Salud Global , Encuestas y Cuestionarios
12.
J Bacteriol ; 204(11): e0027322, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36165621

RESUMEN

Bacteria use adhesins to colonize different surfaces and form biofilms. The species of the Caulobacterales order use a polar adhesin called holdfast, composed of polysaccharides, proteins, and DNA, to irreversibly adhere to surfaces. In Caulobacter crescentus, a freshwater Caulobacterales species, the holdfast is anchored at the cell pole via the holdfast anchor (Hfa) proteins HfaA, HfaB, and HfaD. HfaA and HfaD colocalize with holdfast and are thought to form amyloid-like fibers that anchor holdfast to the cell envelope. HfaB, a lipoprotein, is required for the translocation of HfaA and HfaD to the cell surface. Deletion of the anchor proteins leads to a severe defect in adherence resulting from holdfast not being properly attached to the cell and shed into the medium. This phenotype is greater in a ΔhfaB mutant than in a ΔhfaA ΔhfaD double mutant, suggesting that HfaB has other functions besides the translocation of HfaA and HfaD. Here, we identify an additional HfaB-dependent holdfast anchoring protein, HfaE, which is predicted to be a secreted protein. HfaE is highly conserved among Caulobacterales species, with no predicted function. In planktonic culture, hfaE mutants produce holdfasts and rosettes similar to those produced by the wild type. However, holdfasts from hfaE mutants bind to the surface but are unable to anchor cells, similarly to other anchor mutants. We showed that fluorescently tagged HfaE colocalizes with holdfast and that HfaE forms an SDS-resistant high-molecular-weight species consistent with amyloid fiber formation. We propose that HfaE is a novel holdfast anchor protein and that HfaE functions to link holdfast material to the cell envelope. IMPORTANCE For surface attachment and biofilm formation, bacteria produce adhesins that are composed of polysaccharides, proteins, and DNA. Species of the Caulobacterales produce a specialized polar adhesin, holdfast, which is required for permanent attachment to surfaces. In this study, we evaluate the role of a newly identified holdfast anchor protein, HfaE, in holdfast anchoring to the cell surface in two different members of the Caulobacterales with drastically different environments. We show that HfaE plays an important role in adhesion and biofilm formation in the Caulobacterales. Our results provide insights into bacterial adhesins and how they interact with the cell envelope and surfaces.


Asunto(s)
Adhesión Bacteriana , Caulobacter crescentus , Adhesión Bacteriana/fisiología , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/metabolismo , Caulobacter crescentus/metabolismo , Biopelículas , Polisacáridos/metabolismo
13.
Clin Infect Dis ; 75(11): 1950-1961, 2022 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-36130257

RESUMEN

BACKGROUND: Few data are available on COVID-19 outcomes among pregnant women in sub-Saharan Africa (SSA), where high-risk comorbidities are prevalent. We investigated the impact of pregnancy on SARS-CoV-2 infection and of SARS-CoV-2 infection on pregnancy to generate evidence for health policy and clinical practice. METHODS: We conducted a 6-country retrospective cohort study among hospitalized women of childbearing age between 1 March 2020 and 31 March 2021. Exposures were (1) pregnancy and (2) a positive SARS-CoV-2 RT-PCR test. The primary outcome for both analyses was intensive care unit (ICU) admission. Secondary outcomes included supplemental oxygen requirement, mechanical ventilation, adverse birth outcomes, and in-hospital mortality. We used log-binomial regression to estimate the effect between pregnancy and SARS-CoV-2 infection. Factors associated with mortality were evaluated using competing-risk proportional subdistribution hazards models. RESULTS: Our analyses included 1315 hospitalized women: 510 pregnant women with SARS-CoV-2, 403 nonpregnant women with SARS-CoV-2, and 402 pregnant women without SARS-CoV-2 infection. Among women with SARS-CoV-2 infection, pregnancy was associated with increased risk for ICU admission (adjusted risk ratio [aRR]: 2.38; 95% CI: 1.42-4.01), oxygen supplementation (aRR: 1.86; 95% CI: 1.44-2.42), and hazard of in-hospital death (adjusted sub-hazard ratio [aSHR]: 2.00; 95% CI: 1.08-3.70). Among pregnant women, SARS-CoV-2 infection increased the risk of ICU admission (aRR: 2.0; 95% CI: 1.20-3.35), oxygen supplementation (aRR: 1.57; 95% CI: 1.17-2.11), and hazard of in-hospital death (aSHR: 5.03; 95% CI: 1.79-14.13). CONCLUSIONS: Among hospitalized women in SSA, both SARS-CoV-2 infection and pregnancy independently increased risks of ICU admission, oxygen supplementation, and death. These data support international recommendations to prioritize COVID-19 vaccination among pregnant women.


Asunto(s)
COVID-19 , Complicaciones Infecciosas del Embarazo , Femenino , Embarazo , Humanos , Lactante , COVID-19/epidemiología , SARS-CoV-2 , Estudios Retrospectivos , Mortalidad Hospitalaria , Vacunas contra la COVID-19 , Estudios de Cohortes , África del Sur del Sahara/epidemiología
14.
PLoS Pathog ; 16(6): e1008171, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32492061

RESUMEN

In the absence of effective antiviral therapy, HIV-1 evolves in response to the within-host environment, of which the immune system is an important aspect. During the earliest stages of infection, this process of evolution is very rapid, driven by a small number of CTL escape mutations. As the infection progresses, immune escape variants evolve under reduced magnitudes of selection, while competition between an increasing number of polymorphic alleles (i.e., clonal interference) makes it difficult to quantify the magnitude of selection acting upon specific variant alleles. To tackle this complex problem, we developed a novel multi-locus inference method to evaluate the role of selection during the chronic stage of within-host infection. We applied this method to targeted sequence data from the p24 and gp41 regions of HIV-1 collected from 34 patients with long-term untreated HIV-1 infection. We identify a broad distribution of beneficial fitness effects during infection, with a small number of variants evolving under strong selection and very many variants evolving under weaker selection. The uniquely large number of infections analysed granted a previously unparalleled statistical power to identify loci at which selection could be inferred to act with statistical confidence. Our model makes no prior assumptions about the nature of alleles under selection, such that any synonymous or non-synonymous variant may be inferred to evolve under selection. However, the majority of variants inferred with confidence to be under selection were non-synonymous in nature, and in most cases were have previously been associated with either CTL escape in p24 or neutralising antibody escape in gp41. We also identified a putative new CTL escape site (residue 286 in gag), and a region of gp41 (including residues 644, 648, 655 in env) likely to be associated with immune escape. Sites inferred to be under selection in multiple hosts have high within-host and between-host diversity although not all sites with high between-host diversity were inferred to be under selection at the within-host level. Our identification of selection at sites associated with resistance to broadly neutralising antibodies (bNAbs) highlights the need to fully understand the role of selection in untreated individuals when designing bNAb based therapies.


Asunto(s)
Proteína p24 del Núcleo del VIH/genética , Proteína gp41 de Envoltorio del VIH/genética , Infecciones por VIH/genética , VIH-1/fisiología , Interacciones Huésped-Parásitos/genética , Modelos Genéticos , Selección Genética , Humanos
15.
Phys Rev Lett ; 129(12): 127601, 2022 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-36179158

RESUMEN

We use an x-ray free-electron laser to study the lattice dynamics following photoexcitation with ultrafast near-UV light (wavelength 266 nm, 50 fs pulse duration) of the incipient ferroelectric potassium tantalate, KTaO_{3}. By probing the lattice dynamics corresponding to multiple Brillouin zones through the x-ray diffuse scattering with pulses from the Linac Coherent Light Source (LCLS) (wavelength 1.3 Å and <10 fs pulse duration), we observe changes in the diffuse intensity associated with a hardening of the transverse acoustic phonon branches along Γ to X and Γ to M. Using force constants from density functional theory, we fit the quasiequilibrium intensity and obtain the instantaneous lattice temperature and density of photoexcited charge carriers. The density functional theory calculations demonstrate that photoexcitation transfers charge from oxygen 2p derived π-bonding orbitals to Ta 5d derived antibonding orbitals, further suppressing the ferroelectric instability and increasing the stability of the cubic, paraelectric structure.

16.
Phys Rev Lett ; 128(15): 155301, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35499894

RESUMEN

Using femtosecond time-resolved x-ray diffraction, we investigated optically excited coherent acoustic phonons in the Weyl semimetal TaAs. The low symmetry of the (112) surface probed in our experiment enables the simultaneous excitation of longitudinal and shear acoustic modes, whose dispersion closely matches our simulations. We observed an asymmetry in the spectral line shape of the longitudinal mode that is notably absent from the shear mode, suggesting a time-dependent frequency chirp that is likely driven by photoinduced carrier diffusion. We argue on the basis of symmetry that these acoustic deformations can transiently alter the electronic structure near the Weyl points and support this with model calculations. Our study underscores the benefit of using off-axis crystal orientations when optically exciting acoustic deformations in topological semimetals, allowing one to transiently change their crystal and electronic structures.

17.
J Neurophysiol ; 125(4): 1191-1201, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33566743

RESUMEN

The brainstem noradrenergic locus coeruleus (LC) is reciprocally connected with the prefrontal cortex (PFC). Coupling between LC spiking and the depolarizing phase of slow (1-2 Hz) waves in PFC field potentials during sleep and anesthesia suggests that LC drives cortical state transition. Reciprocal LC-PFC connectivity should also allow interactions in the opposing (top-down) direction, but prior work has only studied prefrontal control over LC activity using electrical or optogenetic stimulation. Here, we describe the physiological characteristics of spontaneously occurring top-down LC-PFC interactions. We recorded LC multiunit activity (MUA) simultaneously with PFC single-unit and local field potential (LFP) activity in urethane-anesthetized rats. We observed cross-regional coupling between the phase of 5-Hz oscillations in LC-MUA and the power of PFC LFP 60-200 Hz high γ (hγ). Transient increases in PFC hγ power preceded peaks in the 5-Hz LC-MUA oscillation. Analysis of cross-regional transfer entropy demonstrated that the PFC hγ transients were predictive of a transient increase in LC-MUA. An ∼29 ms delay between these signals was consistent with the conduction velocity from the PFC to the LC. Finally, we showed that PFC hγ transients are associated with synchronized spiking of a subset (27%) of PFC single units. Our data suggest that PFC hγ transients may indicate the timing of the top-down excitatory input to LC, at least under conditions when LC neuronal population activity fluctuates rhythmically at 5 Hz. Synchronized PFC neuronal spiking that occurs during hγ transients may provide a previously unknown mode of top-down control over the LC.NEW & NOTEWORTHY The prefrontal cortex (PFC) is thought to control activity in the noradrenergic locus coeruleus (LC). Prior anatomical and prefrontal stimulation studies demonstrated the potential for PFC-LC interactions; however, it is unknown what types of PFC activity affect the LC. Here, we show that transient increases in PFC high γ power and associated changes in PFC unit-pair synchrony are a potential sign of top-down control over the LC.


Asunto(s)
Ondas Encefálicas/fisiología , Sincronización de Fase en Electroencefalografía/fisiología , Locus Coeruleus/fisiología , Corteza Prefrontal/fisiología , Animales , Masculino , Ratas , Ratas Sprague-Dawley
18.
BMC Med ; 19(1): 230, 2021 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-34503496

RESUMEN

BACKGROUND: Integration of health services might be an efficient strategy for managing multiple chronic conditions in sub-Saharan Africa, considering the scope of treatments and synergies in service delivery. Proven to promote compliance, integration may lead to increased economies-of-scale. However, evidence on the socio-economic consequences of integration for providers and patients is lacking. We assessed the clinical resource use, staff time, relative service efficiency and overall societal costs associated with integrating HIV, diabetes and hypertension services in single one-stop clinics where persons with one or more of these conditions were managed. METHODS: 2273 participants living with HIV infection, diabetes, or hypertension or combinations of these conditions were enrolled in 10 primary health facilities in Tanzania and Uganda and followed-up for up to 12 months. We collected data on resources used from all participants and on out-of-pocket costs in a sub-sample of 1531 participants, while a facility-level costing study was conducted at each facility. Health worker time per participant was assessed in a time-motion morbidity-stratified study among 228 participants. The mean health service cost per month and out-of-pocket costs per participant visit were calculated in 2020 US$ prices. Nested bootstrapping from these samples accounted for uncertainties. A data envelopment approach was used to benchmark the efficiency of the integrated services. Last, we estimated the budgetary consequences of integration, based on prevalence-based projections until 2025, for both country populations. RESULTS: Their average retention after 1 year service follow-up was 1911/2273 (84.1%). Five hundred and eighty-two of 2273 (25.6%) participants had two or all three chronic conditions and 1691/2273 (74.4%) had a single condition. During the study, 84/2239 (3.8%) participants acquired a second or third condition. The mean service costs per month of managing two conditions in a single participant were $39.11 (95% CI 33.99, 44.33), $32.18 (95% CI 30.35, 34.07) and $22.65 (95% CI 21.86, 23.43) for the combinations of HIV and diabetes and of HIV and hypertension, diabetes and hypertension, respectively. These costs were 34.4% (95% CI 17.9%, 41.9%) lower as compared to managing any two conditions separately in two different participants. The cost of managing an individual with all three conditions was 48.8% (95% CI 42.1%, 55.3%) lower as compared to managing these conditions separately. Out-of-pocket healthcare expenditure per participant per visit was $7.33 (95% CI 3.70, 15.86). This constituted 23.4% (95% CI 9.9, 54.3) of the total monthly service expenditure per patient and 11.7% (95% CI 7.3, 22.1) of their individual total household income. The integrated clinics' mean efficiency benchmark score was 0.86 (range 0.30-1.00) suggesting undercapacity that could serve more participants without compromising quality of care. The estimated budgetary consequences of managing multi-morbidity in these types of integrated clinics is likely to increase by 21.5% (range 19.2-23.4%) in the next 5 years, including substantial savings of 21.6% on the provision of integrated care for vulnerable patients with multi-morbidities. CONCLUSION: Integration of HIV services with diabetes and hypertension control reduces both health service and household costs, substantially. It is likely an efficient and equitable way to address the increasing burden of financially vulnerable households among Africa's ageing populations. Additional economic evidence is needed from longer-term larger-scale implementation studies to compare extended integrated care packages directly simultaneously with evidence on sustained clinical outcomes.


Asunto(s)
Diabetes Mellitus , Infecciones por VIH , Hipertensión , Instituciones de Atención Ambulatoria , Estudios de Cohortes , Infecciones por VIH/epidemiología , Infecciones por VIH/terapia , Servicios de Salud , Humanos , Hipertensión/epidemiología , Hipertensión/terapia , Pobreza , Tanzanía/epidemiología , Uganda/epidemiología
19.
Biometrics ; 77(1): 271-282, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32073645

RESUMEN

In surveillance studies of periodontal disease, the relationship between disease and other health and socioeconomic conditions is of key interest. To determine whether a patient has periodontal disease, multiple clinical measurements (eg, clinical attachment loss, alveolar bone loss, and tooth mobility) are taken at the tooth-level. Researchers often create a composite outcome from these measurements or analyze each outcome separately. Moreover, patients have varying number of teeth, with those who are more prone to the disease having fewer teeth compared to those with good oral health. Such dependence between the outcome of interest and cluster size (number of teeth) is called informative cluster size and results obtained from fitting conventional marginal models can be biased. We propose a novel method to jointly analyze multiple correlated binary outcomes for clustered data with informative cluster size using the class of generalized estimating equations (GEE) with cluster-specific weights. We compare our proposed multivariate outcome cluster-weighted GEE results to those from the convectional GEE using the baseline data from Veterans Affairs Dental Longitudinal Study. In an extensive simulation study, we show that our proposed method yields estimates with minimal relative biases and excellent coverage probabilities.


Asunto(s)
Modelos Estadísticos , Análisis por Conglomerados , Simulación por Computador , Análisis Costo-Beneficio , Humanos , Estudios Longitudinales
20.
J Immunol ; 203(8): 2210-2221, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31519862

RESUMEN

HIV-1 infection expands large populations of late-stage differentiated CD8 T cells that may persist long after viral escape from TCR recognition. In this study, we investigated whether such CD8 T cell populations can perform unconventional innate-like antiviral effector functions. Chronic untreated HIV-1 infection was associated with elevated numbers of CD45RA+CD57+ terminal effector CD8 T cells expressing FcγRIIIA (CD16). The FcγRIIIA+ CD8 T cells displayed a distinctive transcriptional profile between conventional CD8 T cells and NK cells, characterized by high levels of IKZF2 and low expression of IL7R This transcriptional profile translated into a distinct NKp80+ IL-7Rα- surface phenotype with high expression of the Helios transcription factor. Interestingly, the FcγRIIIA+ CD8 T cells mediated HIV-specific Ab-dependent cellular cytotoxicity (ADCC) activity at levels comparable with NK cells on a per cell basis. The FcγRIIIA+ CD8 T cells were highly activated in a manner that correlated positively with expansion of the CD8 T cell compartment and with plasma levels of soluble mediators of antiviral immunity and inflammation such as IP-10, TNF, IL-6, and TNFRII. The frequency of FcγRIIIA+ CD8 T cells persisted as patients initiated suppressive antiretroviral therapy, although their activation levels declined. These data indicate that terminally differentiated effector CD8 T cells acquire enhanced innate cell-like characteristics during chronic viral infection and suggest that HIV-specific ADCC is a function CD8 T cells use to target HIV-infected cells. Furthermore, as the FcγRIIIA+ CD8 T cells persist in treatment, they contribute significantly to the ADCC-capable effector cell pool in patients on antiretroviral therapy.


Asunto(s)
Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Factor de Transcripción Ikaros/inmunología , Receptores de IgG/genética , Receptores de Interleucina-7/inmunología , Adolescente , Adulto , Citotoxicidad Celular Dependiente de Anticuerpos/genética , Linfocitos T CD8-positivos/patología , Diferenciación Celular/inmunología , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Receptores de IgG/inmunología , Adulto Joven
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