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1.
Nature ; 629(8010): 105-113, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38632407

RESUMEN

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.


Asunto(s)
Respiración de la Célula , Ecosistema , Calentamiento Global , Tundra , Regiones Árticas , Carbono/metabolismo , Carbono/análisis , Ciclo del Carbono , Conjuntos de Datos como Asunto , Concentración de Iones de Hidrógeno , Nitrógeno/metabolismo , Nitrógeno/análisis , Plantas/metabolismo , Estaciones del Año , Suelo/química , Microbiología del Suelo , Temperatura , Factores de Tiempo
2.
Cell Death Dis ; 15(1): 30, 2024 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-38212646

RESUMEN

Development of the gonads under complex androgen regulation is critical for germ cells specification. In this work we addressed the relationship between androgens and genomic integrity determining human fertility. We used different study groups: individuals with Differences of Sex Development (DSD), including Complete Androgen Insensitivity Syndrome (CAIS) due to mutated androgen receptor (AR), and men with idiopathic nonobstructive azoospermia. Both showed genome integrity status influenced by androgen signaling via innate immune response activation in blood and gonads. Whole proteome analysis connected low AR to interleukin-specific gene expression, while compromised genome stability and tumorigenesis were also supported by interferons. AR expression was associated with predominant DNA damage phenotype, that eliminated AR-positive Sertoli cells as the degeneration of gonads increased. Low AR contributed to resistance from the inhibition of DNA repair in primary leukocytes. Downregulation of androgen promoted apoptosis and specific innate immune response with higher susceptibility in cells carrying genomic instability.


Asunto(s)
Andrógenos , Receptores Androgénicos , Masculino , Humanos , Andrógenos/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Gónadas , Fertilidad/genética , Células de Sertoli/metabolismo , Inmunidad Innata/genética , Mutación
3.
J Pediatr Adolesc Gynecol ; 36(3): 280-283, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36549464

RESUMEN

BACKGROUND: Since the onset of the COVID-19 pandemic, health care systems have increased their telehealth services to meet the changing public health needs. Before the pandemic, telehealth was used primarily in surgical specialties for postoperative visits and rural medicine. However, out of necessity, nearly all medical and surgical subspecialties incorporated this virtual technology to improve patient health care access in a short time. Few studies have addressed telehealth in pediatric and adolescent gynecology (PAG) to date. STUDY OBJECTIVE: To describe the large-scale utilization of telehealth visits, assess patient experience, and improve access to care in a large academic ambulatory gynecology PAG clinic METHODS: This retrospective, cross-sectional quality improvement study was performed by administering patient surveys and compiling aggregate data from the EPIC electronic health record in the Division of Pediatric and Adolescent Gynecology clinics at a single children's hospital between March 2020 and March 2021. Patient demographic characteristics, payer characteristics, visit type and purpose, and patient experience were reviewed. INTERVENTIONS: Wider expansion of telehealth in PAG clinics at a single institution RESULTS: A total of 6159 telehealth appointments were performed, involving 6 clinic sites and 9 providers. Telehealth visits constituted 50% of the total ambulatory volume (12,527). Most patients were located within the institution's state (99.5%), and the remaining called into their telehealth visits from a neighboring state. Most patients were 18 years of age or younger (73%). Video visits lasted 15-30 minutes and included routine follow-up (66.3%), new/consult visits (28.4%), postoperative visits (1.6%), and urgent follow-up (0.2%). The patient population was ethnically diverse by self-identification: 61.4% White, 38.4% Hispanic, 16% Black, 4.4% Asian, and 0.4% Native Hawaiian/American Indian/Alaska Native. Payer mix included self-pay (45.5%), private payer (32.2%), and Medicaid/CHIP (22.3%). Conditions seen ranged from menstrual management (71%) and routine preventive or acute gynecologic concerns (21%) to surgical evaluation for congenital anomalies, endometriosis, fertility preservation, and genital concerns or pelvic masses (8%). Telehealth visits met patient expectations for 87.3% of respondents. Patient-reported opportunities for improvement included improving set-up instructions and more consistent audio/video connections. Challenges identified by providers included difficulty utilizing interpreters, technology limitations, and privacy constraints during HEADSS examination. CONCLUSIONS: This study demonstrates how a large, diverse volume of patients with PAG needs received appropriate care through a telehealth format during the COVID-19 pandemic. Patients were satisfied with the services, but opportunities for improvement were elicited to allow for continued refining of this health care delivery tool in the future.


Asunto(s)
COVID-19 , Telemedicina , Humanos , Adolescente , Niño , Femenino , Pandemias , COVID-19/epidemiología , Estudios Transversales , Estudios Retrospectivos
4.
S. Afr. med. j. (Online) ; 113(1): 36-41, 2023. figures, tables
Artículo en Inglés | AIM (África) | ID: biblio-1412823

RESUMEN

Background. The high HIV prevalence and incidence in South Africa makes it suitable for recruitment of participants for large-scale HIV preventive vaccine trials. However, fear of vaccine-induced seropositivity (VISP) may be a barrier for community acceptability of the trial, for volunteers to participate in HIV preventive vaccine trials and for uptake of an efficacious vaccine. Prior to 2015, when the first phase 1 safety HIV vaccine trial was undertaken at Setshaba Research Centre, Soshanguve, the local community stakeholders and healthcare workers were naive about HIV vaccine research and HIV preventive vaccines. Objective. To explore knowledge and perceptions regarding VISP among community stakeholders and healthcare workers in peri-urban Soshanguve, Tshwane.Methods. Using a quantitative-qualitative mixed-methods study design, surveys (n=50) and in-depth interviews (n=18) were conducted during July - August 2015. Participants included community stakeholders, community advisory board members and healthcare workers, who were >18 years old and had attended community educational workshops during September 2014 - May 2015. Audio recordings of interviews were transcribed verbatim and coded using content thematic analysis. Data were further analysed by sex, age and educational level.Results. Of a maximum score of 2 on knowledge on VISP, the 50 survey participants (mean age 33.78 years; 45 females) obtained an average of 0.88 (44%). Of 17 in-depth interviewees (one interview could not be transcribed; mean age 30.9 years; 12 females), 8 (47%) displayed some knowledge about VISP, of whom only 5 defined VISP correctly. Women were more knowledgeable about VISP than men; 5 of 12 women (42%) came close to defining VISP correctly, while none of the 5 men did so. The main fear of trial participation expressed by most participants (n=6) was testing HIV-positive as a result of the vaccine. While some participants believed that the community's perceptions of VISP would negatively affect HIV vaccine trial support and recruitment efforts, others noted that if trial participants understand the concept of VISP and are part of support groups, then they would have the information to combat negative attitudes within their community. Conclusion. Most participants had an inaccurate and incomplete understanding of VISP. Many feared testing HIV-positive at clinics; therefore, education on improving a basic understanding of how vaccines work and why VISP occurs is essential. In addition, assessing participant understanding of HIV testing, transmission and VISP is critical for recruitment of participants into HIV vaccine trials and may improve acceptability of an HIV preventive vaccine


Asunto(s)
Humanos , Masculino , Femenino , Infecciones por VIH , Prevalencia , Seropositividad para VIH , Atención a la Salud , Vacunas contra el SIDA , Programas de Inmunización
5.
S Afr Med J ; 113(1): 36-41, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36537546

RESUMEN

BACKGROUND: The high HIV prevalence and incidence in South Africa makes it suitable for recruitment of participants for large-scale HIV preventive vaccine trials. However, fear of vaccine-induced seropositivity (VISP) may be a barrier for community acceptability of the trial, for volunteers to participate in HIV preventive vaccine trials and for uptake of an efficacious vaccine. Prior to 2015, when the first phase 1 safety HIV vaccine trial was undertaken at Setshaba Research Centre, Soshanguve, the local community stakeholders and healthcare workers were naive about HIV vaccine research and HIV preventive vaccines. OBJECTIVE: To explore knowledge and perceptions regarding VISP among community stakeholders and healthcare workers in peri-urbanb Soshanguve, Tshwane. METHODS: Using a quantitative-qualitative mixed-methods study design, surveys (n=50) and in-depth interviews (n=18) were conducted during July - August 2015. Participants included community stakeholders, community advisory board members and healthcare workers, who were >18 years old and had attended community educational workshops during September 2014 - May 2015. Audio recordings of interviews were transcribed verbatim and coded using content thematic analysis. Data were further analysed by sex, age and educational level. RESULTS: Of a maximum score of 2 on knowledge on VISP, the 50 survey participants (mean age 33.78 years; 45 females) obtained an average of 0.88 (44%). Of 17 in-depth interviewees (one interview could not be transcribed; mean age 30.9 years; 12 females), 8 (47%) displayed some knowledge about VISP, of whom only 5 defined VISP correctly. Women were more knowledgeable about VISP than men; 5 of 12 women (42%) came close to defining VISP correctly, while none of the 5 men did so. The main fear of trial participation expressed by most participants (n=6) was testing HIV-positive as a result of the vaccine. While some participants believed that the community's perceptions of VISP would negatively affect HIV vaccine trial support and recruitment efforts, others noted that if trial participants understand the concept of VISP and are part of support groups, then they would have the information to combat negative attitudes within their community. CONCLUSION: Most participants had an inaccurate and incomplete understanding of VISP. Many feared testing HIV-positive at clinics; therefore, education on improving a basic understanding of how vaccines work and why VISP occurs is essential. In addition, assessing participant understanding of HIV testing, transmission and VISP is critical for recruitment of participants into HIV vaccine trials and may improve acceptability of an HIV preventive vaccine.


Asunto(s)
Vacunas contra el SIDA , Investigación Biomédica , Infecciones por VIH , Masculino , Humanos , Femenino , Adulto , Adolescente , Infecciones por VIH/prevención & control , Sudáfrica , Homosexualidad Masculina , Investigación Biomédica/métodos
6.
Nature ; 603(7901): 515-521, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35264792

RESUMEN

Nitrogen availability is a growth-limiting factor in many habitats1, and the global nitrogen cycle involves prokaryotes and eukaryotes competing for this precious resource. Only some bacteria and archaea can fix elementary nitrogen; all other organisms depend on the assimilation of mineral or organic nitrogen. The nitrogen-rich compound guanidine occurs widely in nature2-4, but its utilization is impeded by pronounced resonance stabilization5, and enzymes catalysing hydrolysis of free guanidine have not been identified. Here we describe the arginase family protein GdmH (Sll1077) from Synechocystis sp. PCC 6803 as a Ni2+-dependent guanidine hydrolase. GdmH is highly specific for free guanidine. Its activity depends on two accessory proteins that load Ni2+ instead of the typical Mn2+ ions into the active site. Crystal structures of GdmH show coordination of the dinuclear metal cluster in a geometry typical for arginase family enzymes and allow modelling of the bound substrate. A unique amino-terminal extension and a tryptophan residue narrow the substrate-binding pocket and identify homologous proteins in further cyanobacteria, several other bacterial taxa and heterokont algae as probable guanidine hydrolases. This broad distribution suggests notable ecological relevance of guanidine hydrolysis in aquatic habitats.


Asunto(s)
Hidrolasas , Synechocystis , Arginasa/metabolismo , Proteínas Bacterianas/metabolismo , Guanidina/metabolismo , Hidrolasas/metabolismo , Nitrógeno/metabolismo
7.
J Pediatr Adolesc Gynecol ; 35(1): 98-100, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34284083

RESUMEN

BACKGROUND: Robotic-assisted laparoscopy (RAL) is an alternative to traditional laparoscopic surgery that might increase a surgeon's ability to offer minimally invasive removal of Müllerian remnants (MR) to patients with complex anatomy. We report on 2 cases of RAL resection of MR. CASES: RAL allowed for adequate resection of MR without complications in 2 cases. Case 1 was a 13 year-old female adolescent with VACTERL and uterine remnant close to the ureter of her ipsilateral single kidney. Case 2 was a 16 year-old female adolescent with cloacal exstrophy and omphalocele with remnant hindgut and cervical remnant deep in the pelvis close to the ileal conduit. SUMMARY AND CONCLUSION: In 2 adolescents with complex anatomy and surgical history, RAL allowed for successful removal of MR.


Asunto(s)
Laparoscopía , Procedimientos Quirúrgicos Robotizados , Uréter , Adolescente , Femenino , Humanos , Útero
8.
S Afr Med J ; 111(5): 460-468, 2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-34852889

RESUMEN

BACKGROUND: Health service coverage cascades measure the proportion of a population in need of a service that experienced a positive health outcome from the service, and enable tracking of progress in achieving universal health coverage and inequities in care coverage. OBJECTIVES: To investigate HIV care coverage among HIV-positive adolescent girls and young women (AGYW) living in six South African districts, compare coverage by age and socioeconomic status (SES), and investigate other associated factors including participation in a combination HIV prevention intervention. METHODS: The HERStory Study was an evaluation of the combination intervention, comprising a representative household survey of AGYW aged 15 - 24 years living in six intervention districts. From September 2017 to November 2018, biological, sociodemographic and behavioural data were collected. HIV-positive status, initiation of antiretroviral therapy (ART) and viral suppression were determined through laboratory tests (enzyme-linked immunosorbent assay for HIV antibodies, antiretroviral (ARV) metabolites and viral load (VL) testing). Viral suppression was defined as a VL <1 000 copies/mL. Knowledge of HIV-positive status was self-reported, and participants testing positive for ARV metabolites were assumed to have known their HIV-positive status. Unconditional HIV care cascades were created, stratified by age and SES. We used Pearson's χ2 tests corrected for survey-based analysis to describe factors associated with knowledge of HIV status, and being on ART. RESULTS: Of the 4 399 participants, 568 were HIV-positive (12.4%), of whom 60.8% (95% confidence interval (CI) 57.1 - 64.5) knew their status, 50.6% (95% CI 46.6 - 54.0) were on ART, and 62.1% (95% CI 58.4 - 65.9) were virally suppressed. Most participants (84.9%) were in the lower SES group, and they had better coverage than the higher SES group: 61.9% (95% CI 58.3 - 65.4) knew their status, 52.1% (95% CI 48.4 - 55.9) were on ART, and 64.9% (95% CI 61.3 - 68.4) were virally suppressed, compared with 55.0% (95% CI 42.1 - 68.0), 40.0% (95% CI 29.2 - 50.8), and 46.6% (95% CI 34.5 - 58.7), respectively. Participants aged 15 - 19 years had slightly inferior coverage to the 20 - 24-year-old group: 57.5% knew their status, 46.1% were on ART and 59.5% were virally suppressed, compared with 62.3%, 52.2% and 63.3%. CONCLUSIONS: These findings emphasise the need to close the gaps in HIV care coverage among AGYW, of whom only 61% knew their HIV-positive status and only 62% were virally suppressed. There is pro-poor inequality in HIV care coverage, with those in lower socioeconomic groups more likely to be virally suppressed.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Atención a la Salud/estadística & datos numéricos , Infecciones por VIH/tratamiento farmacológico , Carga Viral , Adolescente , Factores de Edad , Atención a la Salud/economía , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Humanos , Autoinforme , Factores Socioeconómicos , Sudáfrica/epidemiología , Encuestas y Cuestionarios , Adulto Joven
9.
J Pediatr Adolesc Gynecol ; 34(6): 890-892, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34119661

RESUMEN

BACKGROUND: Ehlers-Danlos syndromes (EDS) are a heterogenous group of connective tissue disorders characterized by defective collagen production. Patients with EDS have lax and fragile connective tissue in their joints, skin, blood vessels, and hollow organs. This can lead to, among other complications, joint hypermobility, aneurysms, organ prolapse, and musculoskeletal chronic pain. Given that patients with vaginal agenesis, which occurs with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, often require vaginal dilation as part of their treatment, tissue elasticity and fragility are important considerations. This case report aims to describe the intersection of MRKH and EDS and its impact on vaginal dilation. CASE: A 16-year-old girl with joint hypermobility and type III EDS presented with primary amenorrhea and a karyotype of 46 XX. Magnetic resonance imaging confirmed an absent uterus, cervix, and upper vagina. Physical examination showed Tanner V breasts and Tanner IV pubic hair, and an external genital examination revealed a blind-ending, 1-cm vaginal dimple. The patient was diagnosed with MRKH. Following her diagnosis, she received vaginal dilation instruction and returned for follow-up 2 months later, having quickly progressed to the largest vaginal dilator without symptoms of bleeding, pain, or dysuria. In that timeframe, her vaginal dimple had increased from 1 cm to 7-8 cm in depth, a rate much faster than is typically seen. Because of this rapid progress, a urogenital examination was performed. There was no evidence of urethral abnormality, perforation, or vaginal prolapse. SUMMARY AND CONCLUSION: Recognition of EDS in patients with Müllerian anomalies has important implications for safe and effective vaginal dilation. All patients using vaginal dilation to lengthen the vagina require education on the technique. This need is heightened in patients with EDS in order to prevent accidental dilation of the urethra due to their tissue elasticity, to avoid tissue prolapse, and to prevent the theoretical risk of vaginal perforation.


Asunto(s)
Trastornos del Desarrollo Sexual 46, XX , Anomalías Congénitas , Síndrome de Ehlers-Danlos , Trastornos del Desarrollo Sexual 46, XX/diagnóstico , Adolescente , Anomalías Congénitas/etiología , Síndrome de Ehlers-Danlos/complicaciones , Síndrome de Ehlers-Danlos/diagnóstico , Femenino , Humanos , Conductos Paramesonéfricos/anomalías , Vagina
10.
Nat Commun ; 12(1): 1933, 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33772003

RESUMEN

The perfect absorption of electromagnetic waves has promoted many applications, including photovoltaics, radar cloaking, and molecular detection. Unlike conventional methods of critical coupling that require asymmetric boundaries or coherent perfect absorption that require multiple coherent incident beams, here we demonstrate single-beam perfect absorption in an on-chip cavity magnonic device without breaking its boundary symmetry. By exploiting magnon-mediated interference between two internal channels, both reflection and transmission of our device can be suppressed to zero, resulting in magnon-induced nearly perfect absorption (MIPA). Such interference can be tuned by the strength and direction of an external magnetic field, thus showing versatile controllability. Furthermore, the same multi-channel interference responsible for MIPA also produces level attraction (LA)-like hybridization between a cavity magnon polariton mode and a cavity photon mode, demonstrating that LA-like hybridization can be surprisingly realized in a coherently coupled system.

11.
J Endocrinol Invest ; 44(5): 969-977, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32808162

RESUMEN

BACKGROUND: The homeostatic euthyroid set point of the hypothalamus-pituitary-thyroid axis of any given individual is unique and oscillates narrowly within substantially broader normal population ranges of circulating free thyroxine (FT4) and thyroid-stimulating hormone (TSH), otherwise termed 'thyroid function test (TFT)'. We developed a mathematical algorithm codenamed Thyroid-SPOT that effectively reconstructs the personalized set point in open-loop situations and evaluated its performance in a retrospective patient sample. METHODS: We computed the set points of 101 patients who underwent total thyroidectomy for non-functioning thyroid disease using Thyroid-SPOT on each patient's own serial post-thyroidectomy TFT. Every predicted set point was compared against its respective healthy pre-operative euthyroid TFT per individual and their separation (i.e. predicted-observed TFT) quantified. RESULTS: Bland-Altman analysis to measure the agreement between each pair of an individual's predicted and actual set points revealed a mean difference in FT4 and TSH of + 3.03 pmol/L (95% CI 2.64, 3.43) and - 0.03 mIU/L (95% CI - 0.25, 0.19), respectively. These differences are small compared to the width of the reference intervals. Thyroid-SPOT can predict the euthyroid set point remarkably well, especially for TSH with a 10-16-fold spread in magnitude between population normal limits. CONCLUSION: Every individual's equilibrium euthyroid set point is unique. Thyroid-SPOT serves as an accurate, precise and reliable targeting system for optimal personalized restoration of euthyroidism. This algorithm can guide clinicians in L-thyroxine dose titrations to resolve persistent dysthyroid symptoms among challenging cases harbouring "normal TFT" within the laboratory ranges but differing significantly from their actual euthyroid set points.


Asunto(s)
Enfermedades de la Tiroides/cirugía , Glándula Tiroides , Tiroidectomía , Hormona Liberadora de Tirotropina/sangre , Tirotropina/sangre , Tiroxina , Algoritmos , Cálculo de Dosificación de Drogas , Femenino , Terapia de Reemplazo de Hormonas/métodos , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Valores de Referencia , Enfermedades de la Tiroides/diagnóstico , Enfermedades de la Tiroides/fisiopatología , Pruebas de Función de la Tiroides/métodos , Glándula Tiroides/metabolismo , Glándula Tiroides/cirugía , Tiroidectomía/efectos adversos , Tiroidectomía/métodos , Tiroxina/sangre , Tiroxina/farmacología
12.
J Intern Med ; 289(5): 675-687, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33179374

RESUMEN

BACKGROUND: Several reports have described Takotsubo syndrome (TTS) secondary to thyrotoxicosis. A complex interaction of central and peripheral catecholamines with thyroid homeostasis has been suggested. In this study, we analysed sequential thyroid hormone profiles during the acute phase of TTS. METHODS: Thyrotropin (TSH), free T4 (FT4) and free T3 (FT3) concentrations were analysed at predefined time points in 32 patients presenting with TTS or acute coronary syndrome (ACS, n = 16 in each group) in a 2-year period in two German university hospitals. Data were compared to age- and sex-matched controls (10 samples, each of 16 subjects), and an unsupervised machine learning (ML) algorithm identified patterns in the hormone signature. Subjects with thyroid disease and patients receiving amiodarone were excluded from follow-up. RESULTS: Among patients with TTS, FT4 concentrations were significantly higher when compared to controls or ACS. Four subjects (25%) suffered from subclinical or overt thyrotoxicosis. Two additional patients developed subclinical or overt thyrotoxicosis during stay in hospital. In four subjects (25%), FT4 concentrations were increased, despite nonsuppressed TSH concentration, representing an elevated set point of thyroid homeostasis. The thyroid hormone profile was normal in only six patients (38%) presenting with TTS. CONCLUSION: Abnormal thyroid function is frequent in patients with TTS. Primary hyperthyroidism and an elevated set point of thyroid homeostasis are common in TTS, suggesting a stress-dependent endocrine response or type 2 thyroid allostasis. Thyroid function may be a worthwhile target in treating or preventing TTS.


Asunto(s)
Cardiomiopatía de Takotsubo/complicaciones , Cardiomiopatía de Takotsubo/fisiopatología , Glándula Tiroides/fisiopatología , Tirotoxicosis/complicaciones , Anciano , Femenino , Homeostasis , Humanos , Masculino , Cardiomiopatía de Takotsubo/sangre , Glándula Tiroides/metabolismo , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangre
13.
S Afr Med J ; 110(10): 1050-1055, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-33205738

RESUMEN

BACKGROUND: Young South Africans experience high rates of HIV infection. While nationally scaled medical male circumcision (MMC) can help to curb HIV infection rates in countries such as South Africa (SA), MMC uptake has not been consistent or universal, suggesting variable acceptability among men. Both MMC and traditional male circumcision (TMC) are practised in SA. For male circumcision to be most effective for HIV prevention, it should be performed prior to sexual debut with complete removal of the foreskin. OBJECTIVES: The MACHO (Male Adolescent Choices for HIV Prevention Options) study investigated uptake of and preference for MMC v. TMC in two culturally distinct settings in SA. METHODS: This observational, longitudinal, cohort study investigated circumcision preferences and uptake in 100 males (aged 14 - 17 years) and their legal guardians in Cape Town (Western Cape Province) and Soweto (Gauteng Province). Data were collected via surveys administered every 4 months over a 24-month period. RESULTS: A total of 100 uncircumcised adolescent boys (Cape Town n=50, Soweto n=50; mean (interquartile range) age 15 (14 - 16) years) and their guardians were enrolled. At baseline, 42 boys from Soweto (84%) and none from Cape Town expressed a preference for MMC over TMC. Sowetan participants were more likely to elect circumcision (MMC n=11 (22%), TMC n=1 (2%)) than those from Cape Town (TMC n=1 (2%), MMC n=0) over 13.6 months of follow-up (hazard ratio 18.9; 95% confidence interval 2.37 - 150.71; p=0.006). CONCLUSIONS: MMC was the preferred option for young men in Soweto compared with those in Cape Town, and this translated into practice. Despite knowledge of the benefits of early MMC, many participants delayed uptake, potentially reducing the MMC benefits before sexual debut. Programmes promoting circumcision should consider the influence of local practices. To realise full HIV prevention benefits, efforts should be made to ensure that circumcision is promoted, and that all circumcision is safe, performed prior to sexual debut, and contextually responsive.


Asunto(s)
Circuncisión Masculina/etnología , Circuncisión Masculina/estadística & datos numéricos , Infecciones por VIH/prevención & control , Aceptación de la Atención de Salud/etnología , Aceptación de la Atención de Salud/estadística & datos numéricos , Adolescente , Cultura , Utilización de Instalaciones y Servicios , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estimación de Kaplan-Meier , Estudios Longitudinales , Masculino , Motivación , Utilización de Procedimientos y Técnicas , Modelos de Riesgos Proporcionales , Conducta Sexual , Enfermedades de Transmisión Sexual/prevención & control , Sudáfrica/epidemiología
15.
Trials ; 21(1): 900, 2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-33121503

RESUMEN

BACKGROUND: HIV remains a major public health issue, especially in Eastern and Southern Africa. Pre-exposure prophylaxis is highly effective when adhered to, but its effectiveness is limited by cost, user acceptability and uptake. The cost of a non-inferiority phase III trial is likely to be prohibitive, and thus, it is essential to select the best possible drug, dose and schedule in advance. The aim of this study, the Combined HIV Adolescent PrEP and Prevention Study (CHAPS), is to investigate the drug, dose and schedule of pre-exposure prophylaxis (PrEP) required for the protection against HIV and the acceptability of PrEP amongst young people in sub-Saharan Africa, and hence to inform the choice of intervention for future phase III PrEP studies and to improve strategies for PrEP implementation. METHODS: We propose a mixed-methods study amongst young people aged 13-24 years. The first component consists of qualitative research to identify the barriers and motivators towards the uptake of PrEP amongst young people in South Africa, Uganda and Zimbabwe. The second component is a randomised clinical trial (ClinicalTrials.gov NCT03986970, June 2019) using a novel ex vivo HIV challenge method to investigate the optimal PrEP treatment (FTC-TDF vs FTC-TAF), dose and schedule. We will recruit 144 amongst HIV-negative uncircumcised men aged 13-24 years from voluntary male medical circumcision clinics in two sites (South Africa and Uganda) and randomise them into one of nine arms. One group will receive no PrEP prior to surgery; the other arms will receive either FTC-TDF or FTC-TAF, over 1 or 2 days, and with the final dose given either 6 or 20 h prior to surgery. We will conduct an ex vivo HIV challenge on their resected foreskin tissue. DISCUSSION: This study will provide both qualitative and quantitative results to help decide the optimum drug, dose and schedule for a future phase III trial of PrEP. The study will also provide crucial information on successful strategies for providing PrEP to young people in sub-Saharan Africa. TRIAL REGISTRATION: ClinicalTrials.gov NCT03986970 . Registered on 14 June 2019.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Profilaxis Pre-Exposición , Adolescente , Fármacos Anti-VIH/efectos adversos , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/prevención & control , Humanos , Masculino , Ensayos Clínicos Controlados Aleatorios como Asunto , Sudáfrica , Uganda , Zimbabwe
16.
S Afr Med J ; 110(9): 887-893, 2020 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-32880274

RESUMEN

BACKGROUND: The relationship between HIV and cervical cancer is well established. Interventions that focus on creating human papillomavirus (HPV) vaccine and cervical cancer prevention messaging for adolescents, caregivers and educators will increase uptake of HPV vaccinations, HPV testing and cervical cancer screening for high-risk adolescent girls and young women (AGYW). In order to effectively develop appropriate interventions, it is important to examine AGYW's perceptions regarding their personal risk of acquiring HPV, as well as vaccine acceptability. OBJECTIVES: To measure the level of perceived personal risk of acquiring HPV and developing cervical cancer; examine the sociodemographic and behavioural factors associated with perceived risk; and assess HPV vaccine acceptability. METHODS: AGYW aged 16 - 24 years participating in the AYAZAZI study in Durban, South Africa (SA), were invited to participate in the AYA-HPV Prevention Project (AHPP), and were administered a questionnaire that assessed HPV, cervical cancer and vaccine awareness and knowledge, self-perceived HPV and cervical cancer risk, HPV vaccine uptake and acceptability, and participation in cervical cancer screening. The questionnaire measured self-perceived risk of acquiring HPV and developing cervical cancer for the respondent and other young women, as well as vaccine acceptability. Data from the main AYAZAZI study (12-month) visit were linked to AHPP substudy data. Descriptive statistics were used to analyse sociodemographic variables at the 12-month time point. Self-perceived HIV, HPV and cervical cancer risk was measured using an ordinal scale. Chi-square analyses were used to examine differences in sociodemographic and behavioural factors according to self-perceived risk of HPV and cervical cancer. RESULTS: Only a small portion of participants (14.3%) had heard of HPV. Overall, 43.0% (n=49) perceived themselves as at low HPV risk. There were significant differences in self-perceived risk of cervical cancer by age group, income and pregnancy status. The highest proportion of AGYW who perceived themselves as at high risk of cervical cancer reported being sexually active (p=0.002). Although many participants reported not knowing about HPV prior to the study, after learning about it during the study, most said that they would be willing to receive the vaccine (97.5%). CONCLUSIONS: Most young women in SA do not have access to the national HPV vaccine programme, as only girls in grade 4 in some public schools qualify. Almost all participants indicated that if the vaccine was free and recommended by a healthcare professional, they would accept it. Availability of the HPV vaccine and timely treatment of HPV infections are key issues to address in efforts to decrease cervical cancer worldwide.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus , Neoplasias del Cuello Uterino/prevención & control , Adolescente , Adulto , Factores de Edad , Detección Precoz del Cáncer , Femenino , Humanos , Renta , Infecciones por Papillomavirus/complicaciones , Aceptación de la Atención de Salud , Percepción , Factores de Riesgo , Conducta Sexual , Sudáfrica , Encuestas y Cuestionarios , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/virología , Adulto Joven
17.
Phys Rev Lett ; 124(10): 101102, 2020 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-32216401

RESUMEN

In recent years, many γ-ray sources have been identified, yet the unresolved component hosts valuable information on the faintest emission. In order to extract it, a cross-correlation with gravitational tracers of matter in the Universe has been shown to be a promising tool. We report here the first identification of a cross-correlation signal between γ rays and the distribution of mass in the Universe probed by weak gravitational lensing. We use data from the Dark Energy Survey Y1 weak lensing data and the Fermi Large Area Telescope 9-yr γ-ray data, obtaining a signal-to-noise ratio of 5.3. The signal is mostly localized at small angular scales and high γ-ray energies, with a hint of correlation at extended separation. Blazar emission is likely the origin of the small-scale effect. We investigate implications of the large-scale component in terms of astrophysical sources and particle dark matter emission.

18.
Appl Environ Microbiol ; 86(5)2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-31836576

RESUMEN

Despite glyphosate's wide use for weed control in agriculture, questions remain about the herbicide's effect on soil microbial communities. The existing scientific literature contains conflicting results, from no observable effect of glyphosate to the enrichment of agricultural pathogens such as Fusarium spp. We conducted a comprehensive field-based study to compare the microbial communities on the roots of plants that received a foliar application of glyphosate to adjacent plants that did not. The 2-year study was conducted in Beltsville, MD, and Stoneville, MS, with corn and soybean crops grown in a variety of organic and conventional farming systems. By sequencing environmental metabarcode amplicons, the prokaryotic and fungal communities were described, along with chemical and physical properties of the soil. Sections of corn and soybean roots were plated to screen for the presence of plant pathogens. Geography, farming system, and season were significant factors determining the composition of fungal and prokaryotic communities. Plots treated with glyphosate did not differ from untreated plots in overall microbial community composition after controlling for other factors. We did not detect an effect of glyphosate treatment on the relative abundance of organisms such as Fusarium spp.IMPORTANCE Increasing the efficiency of food production systems while reducing negative environmental effects remains a key societal challenge to successfully meet the needs of a growing global population. The herbicide glyphosate has become a nearly ubiquitous component of agricultural production across the globe, enabling an increasing adoption of no-till agriculture. Despite this widespread use, there remains considerable debate on the consequences of glyphosate exposure. In this paper, we examine the effect of glyphosate on soil microbial communities associated with the roots of glyphosate-resistant crops. Using metabarcoding techniques, we evaluated prokaryotic and fungal communities from agricultural soil samples (n = 768). No effects of glyphosate were found on soil microbial communities associated with glyphosate-resistant corn and soybean varieties across diverse farming systems.


Asunto(s)
Bacterias/aislamiento & purificación , Hongos/aislamiento & purificación , Glicina/análogos & derivados , Herbicidas/administración & dosificación , Microbiota , Raíces de Plantas/microbiología , Microbiología del Suelo , Glicina/administración & dosificación , Maryland , Microbiota/efectos de los fármacos , Mississippi , Micobioma , Glycine max/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo , Glifosato
19.
Phys Rev Lett ; 123(18): 181301, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31763885

RESUMEN

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

20.
Front Microbiol ; 10: 2330, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31649656

RESUMEN

Urbanization results in the systemic conversion of land-use, driving habitat and biodiversity loss. The "urban convergence hypothesis" posits that urbanization represents a merging of habitat characteristics, in turn driving physiological and functional responses within the biotic community. To test this hypothesis, we sampled five cities (Baltimore, MD, United States; Helsinki and Lahti, Finland; Budapest, Hungary; Potchefstroom, South Africa) across four different biomes. Within each city, we sampled four land-use categories that represented a gradient of increasing disturbance and management (from least intervention to highest disturbance: reference, remnant, turf/lawn, and ruderal). Previously, we used amplicon sequencing that targeted bacteria/archaea (16S rRNA) and fungi (ITS) and reported convergence in the archaeal community. Here, we applied shotgun metagenomic sequencing and QPCR of functional genes to the same soil DNA extracts to test convergence in microbial function. Our results suggest that urban land-use drives changes in gene abundance related to both the soil N and C metabolism. Our updated analysis found taxonomic convergence in both the archaeal and bacterial community (16S amplicon data). Convergence of the archaea was driven by increased abundance of ammonia oxidizing archaea and genes for ammonia oxidation (QPCR and shotgun metagenomics). The proliferation of ammonia-oxidizers under turf and ruderal land-use likely also contributes to the previously documented convergence of soil mineral N pools. We also found a higher relative abundance of methanogens (amplicon sequencing), a higher relative abundance of gene sequences putatively identified as Ni-Fe hydrogenase and nickel uptake (shotgun metagenomics) under urban land-use; and a convergence of gene sequences putatively identified as contributing to the nickel transport function under urban turf sites. High levels of disturbance lead to a higher relative abundance of gene sequences putatively identified as multiple antibiotic resistance protein marA and multidrug efflux pump mexD, but did not lead to an overall convergence in antibiotic resistance gene sequences.

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