[Translated article] Immobilisation with compression bandage vs. antebraquial splint in distal radius fractures operated by open reduction and locking plate. Randomised clinical trial.

INTRODUCTION: Currently, there is a lack of prospective studies to unify criteria about type and time for postoperative immobilisation in surgical distal radius fractures. The aim of this study is to compare functional and radiological results in two groups of distal radius fractures treated with internal fixation with locking plate, and immobilised with antebrachial splint or compression bandage for 3 weeks. MATERIAL AND METHOD: A randomised clinical trial was carried out with two parallel groups with 3, 6, and 12 weeks of follow-up. Main and secondary functional variables were measured, such as pain on VAS scale, values on PRWE, DASH and MRS scale, range of motion in flexion-extension, complications, etc. In addition, some radiological variables were measured at preoperative period and one week after surgery, such as union time, dorsal displacement, shortening, ulnar variance, etc. RESULTS: A total of 62 patients were evaluated: 27 immobilised with bandage and 35 with splint. Analysis of the results obtained showed significant differences in both groups for almost all radiological variables from pre to postoperative period, and for all functional variables from 3 to 12 weeks after surgery. No significant differences were found between the two groups for any of the radiological and functional variables evaluated (VAS 3-12 weeks: p=.584; PWRE 3-12 weeks: p=.248; flexion range of motion 3-12 weeks: p=.959; extension range of motion: p=.50; union time: p=.89). CONCLUSIONS: We do not find clinical or radiological differences between immobilisation with antebrachial splint or compression bandage for distal radius fractures operated with locking plate. A greater number of patients and follow-up are necessary to extrapolate the results to the general population and to establish criteria for good postoperative management of these fractures.

Immobilization with compression bandage vs antebraquial splint in distal radius fractures operated by open reduction and locking plate. Randomized clinical trial. / Inmovilización con vendaje compresivo vs férula antebraquial en fracturas de radio distal intervenidas mediante reducción abierta y placa bloqueada. Ensayo clínico aleatorizado.

INTRODUCTION: Currently, there is a lack of prospective studies to unify criteria about type and time for postoperative immobilization in surgical distal radius fractures. The aim of this study is to compare functional and radiological results in two groups of distal radius fractures treated with internal fixation with locking plate, and immobilized with antebrachial splint or compression bandage for 3weeks. MATERIAL AND METHOD: A randomized clinical trial was carried out with two parallel groups with 3, 6, and 12weeks of follow-up. Main and secondary functional variables were measured, such as pain on VAS scale, values on PRWE, DASH and MRS scale, range of motion in flexion-extension, complications, etc. In addition, some radiological variables were measured at preoperative period and one week after surgery, such as union time, dorsal displacement, shortening, ulnar variance, etc. RESULTS: A total of 62 patients were evaluated: 27 immobilized with bandage and 35 with splint. Analysis of the results obtained showed significant differences in both groups for almost all radiological variables from pre to postoperative period, and for all functional variables from 3 to 12weeks after surgery. No significant differences were found between the two groups for any of the radiological and functional variables evaluated (VAS 3-12weeks: P=.584; PWRE 3-12weeks: P=.248; flexion range of motion 3-12weeks: P=.959; extension range of motion: P=.50; union time: P=.89). CONCLUSIONS: We do not find clinical or radiological differences between immobilization with antebrachial splint or compression bandage for distal radius fractures operated with locking plate. A greater number of patients and follow-up are necessary to extrapolate the results to the general population and to establish criteria for good postoperative management of these fractures.

Early effects of acetazolamide on hemoglobin mass and plasma volume in chronic mountain sickness at 5100 m.

INTRODUCTION AND OBJECTIVES: Chronic Mountain Sickness (CMS) syndrome, combining excessive erythrocytosis and clinical symptoms in highlanders, remains a public health concern in high-altitude areas, especially in the Andes, with limited therapeutic approaches. The objectives of this study were to assess in CMS-highlanders permanently living in La Rinconada (5100-5300 m, Peru, the highest city in the world), the early efficacy of acetazolamide (ACZ) and atorvastatin to reduce hematocrit (Hct), as well as the underlying mechanisms focusing on intravascular volumes. MATERIALS AND METHODS: Forty-one males (46±8 years of age) permanently living in La Rinconada for 15 [10-20] years and suffering from CMS were randomized between ACZ (250 mg once-daily; N = 13), atorvastatin (20 mg once-daily; N = 14) or placebo (N = 14) uptake in a double-blinded parallel study. Hematocrit (primary endpoint) as well as arterial blood gasses, total hemoglobin mass (Hbmass) and intravascular volumes were assessed at baseline and after a mean (±SD) treatment duration of 19±2 days. RESULTS: ACZ increased PaO2 by +13.4% (95% CI: 4.3 to 22.5%) and decreased Hct by -5.2% (95% CI: -8.3 to -2.2%), whereas Hct remained unchanged with placebo or atorvastatin. ACZ tended to decrease Hbmass (-2.6%, 95% CI: -5.7 to 0.5%), decreased total red blood cell volume (RBCV, -5.3%, 95% CI: -10.3 to -0.3%) and increased plasma volume (PV, +17.6%, 95% CI: 4.9 to 30.3%). Atorvastatin had no effect on intravascular volumes, while Hbmass and RBCV increased in the placebo group (+6.1%, 95% CI: 4.2 to 7.9% and +7.0%, 95%CI: 2.7 to 11.4%, respectively). CONCLUSIONS: Short-term ACZ uptake was effective to reduce Hct in CMS-highlanders living at extreme altitude >5,000 m and was associated with both an increase in PV and a reduction in RBCV.

Emerging Evidence on the Use of Probiotics and Prebiotics to Improve the Gut Microbiota of Older Adults with Frailty Syndrome: A Narrative Review.

BACKGROUND: The gut microbiota can impact older adults' health, especially in patients with frailty syndrome. Understanding the association between the gut microbiota and frailty syndrome will help to explain the etiology of age-related diseases. Low-grade systemic inflammation is a factor leading to geriatric disorders, which is known as "inflammaging". Intestinal dysbiosis has a direct relationship with low-grade systemic inflammation because when the natural gut barrier is altered by age or other factors, some microorganisms or their metabolites can cross this barrier and reach the systemic circulation. OBJECTIVES: This review had two general goals: first, to describe the characteristics of the gut microbiota associated with age-related diseases, specifically frailty syndrome. The second aim was to identify potential interventions to improve the composition and function of intestinal microbiota, consequently lessening the burden of patients with frailty syndrome. METHODS: A search of scientific evidence was performed in PubMed, Science Direct, and Redalyc using keywords such as "frailty", "elderly", "nutrient interventions", "probiotics", and "prebiotics". We included studies reporting the effects of nutrient supplementation on frailty syndrome and older adults. These studies were analyzed to identify novel therapeutic alternatives to improve gut microbiota characteristics as well as subclinical signs related to this condition. RESULTS: The gut microbiota participates in many metabolic processes that have an impact on the brain, muscles, and other organs. These processes integrate feedback mechanisms, comprising their respective axis with the intestine and the gut microbiota. Alterations in these associations can lead to frailty. We report a few interventions that demonstrate that prebiotics and probiotics could modulate the gut microbiota in humans. Furthermore, other nutritional interventions could be used in patients with frailty syndrome. CONCLUSION: Probiotics and prebiotics may potentially prevent frailty syndrome or improve the quality of life of patients with this disorder. However, there is not enough information about their appropriate doses and periods of administration. Therefore, further investigations are required to determine these factors and improve their efficacy as therapeutic approaches for frailty syndrome.

Description of the methodology for dosimetric quantification in treatments with 177Lu-DOTATATE. / Descripción de la metodología para la cuantificación dosimétrica en tratamientos con 177Lu-DOTATATE.

Implementation of dosimetry calculations in the daily practice of Nuclear Medicine Departments is, at this time, a controversial issue, partly due to the lack of a standardized methodology that is accepted by all interested parties (patients, nuclear medicine physicians and medical physicists). However, since the publication of RD 601/2019 there is a legal obligation to implement it, despite the fact that it is a complex and high resource consumption procedure. The aim of this article is to review the theoretical bases of in vivo dosimetry in treatments with 177Lu-DOTATATE. The exposed methodology is the one proposed by the MIRD Committee (Medical Internal Radiation Dose) of the SNMMI (Society of Nuclear Medicine & Molecular Imaging). According to this method, the absorbed dose is obtained as the product of 2factors: the time-integrated activity of the radiopharmaceutical present in a source region and a geometrical factor S. This approach, which a priori seems simple, in practice requires several SPECT/CT acquisitions, several measurements of the whole body activity and taking several blood samples, as well as hours of image processing and computation. The systematic implementation of these calculations, in all the patients we treat, will allow us to obtain homogeneous data to correlate the absorbed doses in the lesions with the biological effect of the treatment. The final purpose of the dosimetry calculations is to be able to maximize the therapeutic effect in the lesions, controlling the radiotoxicity in the organs at risk.

Seguridad del paciente: percepción de estudiantes de una universidad pública / Patient safety: Perceptions of students in a public university / Segurança do paciente: percepção de estudantes de uma universidade pública

RESUMEN Introducción: La seguridad del paciente es una prioridad mundial para los sistemas de salud. Las instituciones educativas formadoras de recursos humanos deben incluir la temática en su currículo. Objetivo: Identificar la percepción sobre la seguridad del paciente en los estudiantes de licenciatura en enfermería. Metodología: Estudio descriptivo y transversal. Población total de 516 alumnos de licenciatura en enfermería de la Universidad Autónoma de Tamaulipas, México. Se utilizó el cuestionario APQS-III y se diseñó una cédula con variables sociodemográficas. Resultados: La mayoría de los participantes son mujeres, edad promedio: 20 años. La mitad de los alumnos no tiene cursos que avalen sus conocimientos sobre seguridad del paciente. En la dimensión entrenamiento recibido, 63.5 % concuerda que la formación de pregrado los capacita para entender las causas de un evento adverso por enfermería, los habilita para prevenir errores y desarrollar una adecuada comprensión en materia de seguridad. 50.3 % está totalmente de acuerdo en la dimensión confianza en el reporte del error y es semejante la proporción en la dimensión horas de trabajo como causas de error. Discusión: La identificación positiva de la percepción que se tiene acerca de la seguridad del paciente por parte de los estudiantes, favorece desde el pregrado la creación de una cultura de seguridad que fomenta la confianza y el interés de estos para desarrollar un enfoque integrado en el tema estudiado. Conclusiones: Los estudiantes en su mayoría refieren actitudes positivas confiados en que su entrenamiento sobre seguridad los prepara para entender y prevenir las causas de errores en seguridad del paciente.

ABSTRACT Introduction: Patient safety is a priority of health systems worldwide and therefore, the education institutions responsible for the formation of human resources for health must address this goal in detail. Objective: To identify the perceptions of baccalaureate nursing students regarding patient safety. Methodology: This is a descriptive and transversal study on 516 baccalaureates in nursing students from the Universidad Autónoma de Tamaulipas, Mexico. The APQS-III and a specific social-demographic data questionnaire were used. Results: The majority of the participants were female. The average age was 20 years old. Nearly half of the students do not have enough courses to strengthen their knowledge on patient safety. Regarding the training received, 63.5 % of the participants agree that the baccalaureate level formation prepares them to understand the causes of adverse events in nursing, to prevent errors, and to have an adequate understanding of security. 50.3 % of the participants approved the dimension's confidence approach regarding error reporting. Many participants considered that the excessive long hours working dimension is a cause of errors. Discussion: The perception of patient safety as being very important favors and further promotes a culture of security. Conclusions: The majority of the students trust their training regarding patient safety and know how to prevent possible causes of errors.

RESUMO Introdução: A segurança do paciente é uma prioridade mundial para os sistemas de saúde. As instituições educacionais formadoras de recursos humanos devem incluir a temática em seu currículo. Objetivo: Identificar a percepção sobre a segurança do paciente nos estudantes de graduação em enfermagem. Metodologia: Estudo descritivo e transversal. População total de 516 alunos de graduação em enfermagem da Universidad Autónoma de Tamaulipas, México. Foi utilizado o questionário APQS-III e realizou-se um questionário com variáveis sociodemográficas. Resultados: A maioria dos participantes são mulheres, idade média: 20 anos. Metade dos estudantes não tem cursos que avaliem seus conhecimentos sobre segurança do paciente. Na dimensão do treinamento recebido, 63,5 % concordam que a formação de graduação os treina para entender as causas de um evento de enfermagem adverso, lhes permite prevenir erros e desenvolver uma compreensão adequada da segurança. 50,3 % concordam fortemente sobre a dimensão de confiança no relatório dos erros e a proporção e da mesma forma sobre a dimensão das horas de trabalho como causa dos erros. Discussão: A identificação positiva da percepção que se tem sobre a segurança do paciente por parte dos alunos, favorece desde a graduação a criação de uma cultura de segurança que fomente a confiança e o interesse destes em desenvolver uma abordagem integrada na o assunto estudado. Conclusões: A maioria dos alunos relata atitudes positivas, confiantes de que seu treinamento em segurança os prepara para compreender e prevenir as causas dos erros na segurança do paciente.

The levonorgestrel intrauterine system for prevention of endometrial cancer in women with obesity: A cost-effectiveness study.

OBJECTIVE: To estimate the cost-effectiveness of the levonorgestrel intrauterine system (LNG-IUS) as an endometrial cancer prevention strategy in women with obesity. METHODS: A Markov decision-analytic model was used to compare 5 strategies in women with a body mass index of 30 or greater: 1) Usual care 2) LNG-IUS for 5 years 3) LNG-IUS for 7 years 4) LNG-IUS for 5 years, replaced once for a total of 10 years 5) LNG-IUS for 7 years, replaced once for a total of 14 years. Obesity was presumed to be associated with a 3-fold relative risk of endometrial cancer incidence and a 2.65-fold disease-specific mortality. The LNG-IUS was assumed to confer a 50% reduction in cancer incidence over the period of the LNG-IUS insertion. Outcomes were incremental cost-effectiveness ratios, calculated in 2019 Canadian dollars (CAD) per year of life saved. One-way and two-way sensitivity analyses were performed. RESULTS: The LNG-IUS strategy was considered cost-effective if the cost of the intervention is less than $66,400 CAD ($50,000 US dollars) per year of life saved. The strategy becomes cost-effective if the LNG-IUS is inserted at age 57 (strategy #2), at age 52 for strategy #3, at age 51 for strategy #4 and at age 45 for strategy #5, when compared to usual care. The results are stable to variations in cost but sensitive to the estimated risk reduction of the LNG-IUS and the impact of obesity on endometrial cancer incidence and disease-specific mortality. CONCLUSION: The LNG-IUS is a cost-effective method of endometrial cancer prevention in women with obesity.

Pathological characteristics, survival, and risk of breast cancer associated with estrogen and xenobiotic metabolism polymorphisms in Mexican women with breast cancer.

Prolonged exposure to estrogens is the main factor associated with the risk and prognosis of breast cancer (BC). The genes involved in the biotransformation of estrogens and xenobiotics have allelic variants with modified enzymatic activities. We investigated the association of nine polymorphisms of some genes from the classical estrogen pathway with the risk of breast cancer and their role in the clinicopathological characteristics of poor clinical prognosis in a sample of Mexican women with BC. METHODS: We included 150 controls and 150 cases matched by age. To analyze the selected polymorphisms, TaqMan assays and high-resolution melting (HRM) analysis were used. RESULTS: The polymorphisms of the genes ERα, CYP1A1, CYP1B1, COMT, MGMT, and XRCC1 were positively associated with the BC risk. We found negative associations between CYP1B1G/G genotype and tumor size, and status of lymph node, estrogen receptor, triple negative, and survival. CONCLUSIONS: The polymorphisms included in this study are associated not only with the risk of BC, but also with some clinicopathological characteristics for poor prognosis of patients with breast cancer, highlighting the important role of CYP1B1 Leu432Val polymorphism.

Benign epithelial oral lesions - association with human papillomavirus.

BACKGROUND: The presence of human papilloma virus in benign oral lesions has been studied by different techniques obtaining extremely variable results. The objective of this study was to determine the presence of human papillomavirus in 83 cases of benign hyperplastic epithelial oral lesions. MATERIAL AND METHODS: Eighty-three oral lesions with clinical or histopathological features suggestive of HPV infection were retrieved from the files of four oral pathology services. Demographic data were obtained from patient's medical charts. All cases had available clinical image, H&E preparations and paraffin blocks with enough tissue for HPV detection by in situ hybridization, and immunohistochemical reactions for Ki67. RESULTS: Episomal positivity for wide spectrum HPV was observed in 24% of the cases; most of them (70%) HPV 6/11 positive. HPV 16/18 was not detected. Condyloma acuminatum was the most common lesion associated with HPV (75%), followed by verruca vulgaris (15%), squamous papilloma and multifocal epithelial hyperplasia, 5% each. Koilocytes were identified in all the HPV positive cases. Ki67 showed an abnormal proliferation pattern in 90% of the HPV positive cases; most of them (70%) showing groups of proliferating cells in focal superficial regions, and in 20% positivity was seen almost in the whole thickness of the epithelium. HPV negative cases showed Ki67 positive cells restricted to the basal layer. CONCLUSIONS: Regarding oral lesions associated with HPV, condyloma is the most common lesion expressing low-risk subtypes. The etiology of squamous papilloma remains controversial as HPV was found in 1.9% of the cases. The identification of koilocytes and the pattern of expression of Ki67 reflect HPV infection and are helpful for classification. Papillary oral lesions not associated to HPV deserve further studies to better clarify its etiology.

Mycobacterium marinum lymphocutaneous infection.

Mycobacterium marinum is a nontuberculous mycobacteria with worldwide distribution that lives in fresh or salt water and is responsible for infections in fish, and sometimes in humans. Human disease consists mainly of cutaneous nodules, but deep structure involvement may also occur. Diagnosis of M. marinum infection remains a challenge, with a considerable time delay between onset of symptoms and diagnosis. We present a 33-year-old man with no immunosuppressive history who was seen in our department with skin nodules over his hand and forearm, distributed in a sporotrichoid pattern. His hobbies included maintaining an aquarium of tropical fish. Histological examination of the patient's skin biopsy was compatible with the diagnosis of mycobacterial infection, and the Ziehl-Neelsen staining revealed acid-fast bacilli. Molecular techniques confirmed the suspicion of M. marinum infection. A necropsy was performed on one of the patient's fish, more specifically, a Poecilia reticulata, and resulted in identification of M. marinum from its gut. The patient was treated with clarithromycin, ethambutol, and rifampicin for 9 months, with clearance of infection.

Simultaneous Silicon Oxide Growth and Electrophoretic Deposition of Graphene Oxide.

During electrophoretic deposition of graphene oxide (GO) sheets on silicon substrates, not only deposition but also simultaneous anodic oxidation of the silicon substrate takes place, leading to a three-layered material. Scanning electron microscopy images reveal the presence of GO sheets on the silicon substrate, and this is also confirmed by X-ray photoelectron spectroscopy (XPS), albeit that the carbon portion increases with increasing emission angle, hinting at a thin carbon layer. With increasing applied potential and increasing conductivity of the GO solution, the carbon signal decreases, whereas the overall thickness of the added layer formed on top of the silicon substrate increases. Through XPS spectra in which the Si 2p peaks shifted under those conditions to 103-104 eV, we were able to conclude that significant amounts of oxygen are present, indicative of the formation of an oxide layer. This leads us to conclude that GO can be deposited using electrophoretic deposition, but that at the same time, silicon is oxidized, which may overshadow effects previously assigned to GO deposition.

[Installed Capacity Perception Survey for the Training of Residents Program in Orthopedics and Care Needs in Acute and Chronic Musculoskeletal Pathology in Mexico]. / Encuesta de Percepción en Capacidad Instalada para la Formación de Médicos Residentes en Ortopedia (Traumatología) y Necesidades de la Atención en Patología Musculoesquelética Aguda y Crónica en México. Primera Parte.

INTRODUCTION: It is essential that orthopaedic resident physicians be highly proficient in all aspects, considering the balance between supply, demand, need and context. Fundamental to identify the capacity and quality installed for their training in Mexico. MATERIAL AND METHODS: Observational Study, transverse, non-probabilistic sampling-conglomerates, in two phases. The instrument has 8 domains, 57 variables and 4,867 items. 60 graduate professors of 20 states, 50 hospital sites, 22 university programs. RESULTS: 1,038 years of experience (collective intelligence), 17 years of experience/teacher (01 to 50 years). Identified: acute pathology 30 (2 to 90%), chronic pathology 30 (5 to 96%), patients 15 years, 10 (3 to 30%), patients between 15 and 65 years, 47 (2 to 78%), patients 65 years, 20 (2 to 60%), number of beds/seat 20 (2 to 510), number of clinics 3 (1 to 48), number of surgical procedures/headquarters per year at the national level, was 960 (50 to 24,650). The national average per resident doctor is 362 surgeries/year with 1,450 surgical times/year. CONCLUSIONS: The needs and resources for the training of physicians specializing in orthopedics/traumatology are highly heterogeneous, so it should be adapted to the epidemiological needs of the region of influence, in an area of epidemiological transition. 62.2% expressed not having or have bad academic and scientific infrastructure at its headquarters, more than 50% without rotation overseas and 90% without regular scientific production.

INTRODUCCIÓN: Es fundamental que los médicos residentes de ortopedia (traumatología) sean altamente competentes en todos los aspectos, considerando el equilibrio entre la oferta, demanda, necesidad y contexto. Es primordial identificar la capacidad y calidad instalada para su formación en México. MATERIAL Y MÉTODOS: Estudio observacional, transversal, muestreo no probabilístico-conglomerados, en dos fases. El instrumento tiene ocho dominios, 57 variables y 4,867 ítems. Sesenta profesores de postgrado de 20 estados, 50 sedes hospitalarias, 22 programas universitarios. RESULTADOS: 1,038 años de experiencia (inteligencia colectiva), 17 años de experiencia/profesor (01 a 50 años). Se identificó: patología aguda 30 (2 a 90%), patología crónica 30 (5 a 96%), pacientes 15 años, 10 (3 a 30%), pacientes entre 15 y 65 años, 47 (2 a 78%), pacientes 65 años, 20 (2 a 60%), número de camas/sede 20 (2 a 510), número de consultorios 3 (1 a 48), el número de procedimientos quirúrgicos/sede al año a nivel nacional fue de 960 (50 a 24,650). La media nacional por médico residente es de 362 cirugías/año con 1,450 momentos quirúrgicos/año. CONCLUSIONES: Las necesidades y recursos para la formación de médicos especialistas en ortopedia/traumatología son en alto grado heterogéneos, por lo cual se debería adaptar a las necesidades epidemiológicas de la región de influencia, en un ámbito de transición epidemiológica. Sesenta y dos punto dos por ciento expresó no tener o tener deficiente infraestructura académica y científica en su sede, más de 50% sin rotación al extranjero y 90% sin producción científica regular.

Frequency analysis of the laser driven nonlinear dynamics of HCN.

We study the vibrational dynamics of a model for the HCN molecule in the presence of a monochromatic laser field. The variation of the structural behavior of the system as a function of the laser frequency is analyzed in detail using the smaller alignment index, frequency maps, and diffusion coefficients. It is observed that the ergodicity of the system depends on the frequency of the excitation field, especially in its transitions from and into chaos. This provides a roadmap for the possibility of bond excitation and dissociation in this molecule.

ICAM-1 expression on immune cells in chronic villitis.

INTRODUCTION: ICAM-1 expression on the villous syncytiotrophoblast (ST) is believed to participate in migration of maternal cells into the inflamed villi regardless of villitis etiology. However, its expression on immune cells in chronic villitis (CV) has yet to be analyzed. ICAM-1 induces cell-cell adhesion allowing intercellular communication, T cell-mediated defense mechanism, and inflammatory response. MATERIAL AND METHODS: 21 cases of CV (all without an identifiable etiologic agent) and 3 control placentas were analyzed using ICAM-1, and for immune cells CD45, CD3 and CD68. These cells were subdivided according to their location in inflamed villi: a) within the inflamed villi and b) outside forming perivillous aggregates. RESULTS: Large amounts of CD45, CD3 and CD68 were found within the inflamed villi and forming perivillous aggregates attached to areas of trophoblastic loss. Inflamed villi usually showed ICAM-1+ ST. The majority of immune cells surrounding areas of trophoblastic rupture presented marked expression of ICAM-1. In contrast, a small number of immune cells within the inflamed villi exhibited ICAM-1 expression. Only some (<5%) inflamed villi without trophoblastic rupture and with ICAM-1+ ST presented adherence of immune cells. DISCUSSION: In inflamed villi of chronic villitis, the level of ICAM-1 expression on immune cells depends on their location: high in number of cells in the perivillous region and low within the villi. The strongest expression of ICAM-1 on immune cells attached to areas of trophoblastic rupture suggests that the loss of trophoblast can lead to an amplification of the inflammatory response.

The vertebrate homologue of sulfide-quinone reductase in mammalian mitochondria.

Hydrogen sulfide (H2S) is the first inorganic compound identified as both a substrate for mitochondrial oxidative phosphorylation and a transmitter in mammalian cells. H2S seems to mediate effects that are correlated with those of nitric oxide (NO) by a reciprocal regulation. Moreover, H2S is consumed by mitochondrial oxidation mediated by sulfide-quinone reductase-like protein (SQRDL)-the vertebrate homolog of sulfide-quinone oxidoreductase (SQR). There is evidence that SQR plays an essential role in regulating H2S levels in fission yeast. To start understanding the role of SQRDL in the mammalian metabolism of H2S, we examine rat tissues. Our results show that SQRDL protein is present in all tissues tested, albeit restricted to specific mitochondrial populations at the cellular level. We demonstrate a developmental regulation of Sqrdl transcription in the kidney, where SQRDL protein is detectable in glomerular podocytes and in tubular cells of the renal medulla. We also show that Sqrdl transcription in T cells is responsive to external H2S. Taken together, our results suggest that Sqrdl transcription is adaptively regulated, probably to meet the need of H2S oxidation. Thus far, SQRDL has only been studied in a limited set of tissues. The present report demonstrates the presence and specific localization of SQRDL in various mammalian tissues.