Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Biochem Biophys Res Commun ; 524(4): 1030-1036, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32063359

RESUMO

The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by a family of four genes (HCN1-4). All isoforms are expressed in the heart, HCN4 being the most abundant in the sinoatrial node (SAN). HCN channels are responsible for the "funny" current (If) associated with the generation and autonomic control of the diastolic depolarization phase of cardiac action potential. In this work we performed a proteomic analysis of HCN4 transfected in HEK293 cells. Most of the identified proteins in the HCN4 network belonged to mitochondria. The subcellular localization of HCN channels was predicted in plasma membrane, mitochondria and nucleus. Experimentally, HCN2 (full-length, truncated), HCN3 (full-length, truncated) and HCN4 (truncated) were detected in rat heart mitochondria by immunoblotting. If sensitive to ZD7288, was recorded by patch-clamp in mitoplasts from cardiomyocytes. Mitochondrial membrane potential (ΔΨm) assessment in H9c2 cells revealed that ZD7288 induced almost 50% higher hyperpolarization respect to control at 30 min. Furthermore, ZD7288 reduced oxygen consumption attributed to ATP synthesis in H9c2 cells. In conclusion, we identify for the first time functional HCN channels in mammalian cardiac mitochondria and demonstrate their impact on ΔΨm and respiration.


Assuntos
Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias Cardíacas/metabolismo , Consumo de Oxigênio , Animais , Linhagem Celular , Células HEK293 , Humanos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/análise , Camundongos Endogâmicos BALB C , Miócitos Cardíacos/metabolismo , Ratos Wistar
2.
Int J Mol Sci ; 20(20)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31601020

RESUMO

Hyperpolarization-activated cationic HCN channels comprise four members (HCN1-4) that control dendritic integration, synaptic transmission and action potential firing. In the kidney, HCN1, HCN2 and HCN3 are differentially expressed and contribute to the transport of sodium, potassium (K+) and ammonium into the nephrons. HCN3 is regulated by K+ diets in the kidney. In this work we performed a proteomic analysis of HCN3 expressed in human embryonic kidney cells (HEK293 cells). More than 50% of the interacting proteins belonged to mitochondria. Therefore, we explored the presence of HCN channels in kidney mitochondria. By immunoblotting and immunogold electron microscopy HCN3 protein expression was found in rat kidney mitochondria; it was also confirmed in human kidney. Patch-clamp recordings of renal mitochondria and mitochondria from HEK293 cells overexpressing HCN1, HCN2 and HCN3 channels, stained with MitoTracker Green FM, indicated that only HCN3 could produce inwardly K+ currents that were inhibited by ZD7288, a specific blocker of HCN channels. Furthermore, ZD7288 caused inhibition of the oxygen consumption coupled to ATP synthesis and hyperpolarization of the inner mitochondrial membrane. In conclusion, we show for the first time that pacemaker HCN channels contribute to K+ transport in mitochondria facilitating the activity of the respiratory chain and ATP synthesis by controlling the inner mitochondrial membrane potential.


Assuntos
Rim/metabolismo , Mitocôndrias/metabolismo , Canais de Potássio/metabolismo , Potenciais de Ação , Respiração Celular , Cromatografia Líquida , Ativação do Canal Iônico , Mitocôndrias/genética , Nucleotídeos Cíclicos/metabolismo , Proteoma , Proteômica/métodos , Espectrometria de Massas em Tandem
3.
J Card Fail ; 24(3): 186-201, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28939458

RESUMO

BACKGROUND: The effects of mind-body interventions (MBIs) (eg, Tai Chi, yoga, meditation) for individuals with heart failure (HF) have not been systematically evaluated. METHODS AND RESULTS: We performed a systematic review of randomized controlled trials (RCTs) examining the effects of MBIs in HF. We extracted participant characteristics, MBI procedure, outcomes assessed, and main results of English-language RCTs before October 2016. We identified 24 RCTs (n = 1314 participants) of 9 MBI types: Tai Chi (n = 7), yoga (n = 4), relaxation (n = 4), meditation (n = 2), acupuncture (n = 2), biofeedback (n = 2), stress management (n = 1), Pilates (n = 1), and reflexology (n = 1). Most (n = 22, 95.8%) reported small-to-moderate improvements in quality of life (14/14 studies), exercise capacity (8/9 studies), depression (5/5 studies), anxiety and fatigue (4/4 studies), blood pressure (3/5 studies), heart rate (5/6 studies), heart rate variability (7/9 studies), and B-type natriuretic peptide (3/4 studies). Studies ranged from 4 minutes to 26 weeks and group sizes ranged from 8 to 65 patients per study arm. CONCLUSIONS: Although wide variability exists in the types and delivery, RCTs of MBIs have demonstrated small-to-moderate positive effects on HF patients' objective and subjective outcomes. Future research should examine the mechanisms by which different MBIs exert their effects.


Assuntos
Insuficiência Cardíaca/terapia , Terapias Mente-Corpo/métodos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Insuficiência Cardíaca/psicologia , Humanos
4.
J Natl Compr Canc Netw ; 13(8): 1012-39, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26285247

RESUMO

Cancer-related fatigue is defined as a distressing, persistent, subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning. It is one of the most common side effects in patients with cancer. Fatigue has been shown to be a consequence of active treatment, but it may also persist into posttreatment periods. Furthermore, difficulties in end-of-life care can be compounded by fatigue. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cancer-Related Fatigue provide guidance on screening for fatigue and recommendations for interventions based on the stage of treatment. Interventions may include education and counseling, general strategies for the management of fatigue, and specific nonpharmacologic and pharmacologic interventions. Fatigue is a frequently underreported complication in patients with cancer and, when reported, is responsible for reduced quality of life. Therefore, routine screening to identify fatigue is an important component in improving the quality of life for patients living with cancer.


Assuntos
Fadiga/diagnóstico , Fadiga/etiologia , Fadiga/terapia , Neoplasias/complicações , Gerenciamento Clínico , Humanos , Neoplasias/terapia , Padrão de Cuidado
5.
Resusc Plus ; 17: 100539, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38268847

RESUMO

Background: The objective of this study was to determine if regional cerebral oximetry (rSO2) assessed during CPR would be predictive of survival with favorable neurological function in a prolonged model of porcine cardiac arrest. This study also examined the relative predictive value of rSO2 and end-tidal carbon dioxide (ETCO2), separately and together. Methods: This study is a post-hoc analysis of data from a previously published study that compared conventional CPR (C-CPR) and automated head-up positioning CPR (AHUP-CPR). Following 10 min of untreated ventricular fibrillation, 14 pigs were treated with either C-CPR (C-CPR) or AHUP-CPR. rSO2, ETCO2, and other hemodynamic parameters were measured continuously. Pigs were defibrillated after 19 min of CPR. Neurological function was assessed 24 h later. Results: There were 7 pigs in the neurologically intact group and 7 pigs in the poor outcomes group. Within 6 min of starting CPR, the mean difference in rSO2 by 95% confidence intervals between the groups became statistically significant (p < 0.05). The receiver operating curve for rSO2 to predict survival with favorable neurological function reached a maximal area under the curve value after 6 min of CPR (1.0). The correlation coefficient between rSO2 and ETCO2 during CPR increased towards 1.0 over time. The combined predictive value of both parameters was similar to either parameter alone. Conclusion: Significantly higher rSO2 values were observed within less than 6 min after starting CPR in the pigs that survived versus those that died. rSO2 values were highly predictive of survival with favorable neurological function.

6.
Arch Med Res ; 54(6): 102859, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37516009

RESUMO

BACKGROUND: Bartter's syndrome (BS) is a group of salt-wasting tubulopathies characterized by hypokalemia, metabolic alkalosis, hypercalciuria, secondary hyperaldosteronism, and low or normal blood pressure. Loss-of-function variants in genes encoding for five proteins expressed in the thick ascending limb of Henle in the nephron, produced different genetic types of BS. AIM: Clinical and genetic analysis of families with Antenatal Bartter syndrome (ABS) and with Classic Bartter syndrome (CBS). METHODS: Nine patients from unrelated non-consanguineous Mexican families were studied. Massive parallel sequencing of a gene panel or whole-exome sequencing was used to identify the causative gene. RESULTS: Proband 1 was homozygous for the pathogenic variant p.Arg302Gln in the SLC12A1 gene encoding for the sodium-potassium-chloride NKCC2 cotransporter. Proband 3 was homozygous for the nonsense variant p.Cys308* in the KCNJ1 gene encoding for the ROMK potassium channel. Probands 7, 8, and 9 showed variants in the CLCKNB gene encoding the chloride channel ClC-Kb: proband 7 was compound heterozygous for the deletion of the entire gene and the missense change p.Arg438Cys; proband 8 presented a homozygous deletion of the whole gene and proband 9 was homozygous for the nonsense mutation p.Arg595*. A heterozygous variant of unknown significance was detected in the SLC12A1 gene in proband 2, and no variants were found in SLC12A1, KCNJ1, BSND, CLCNKA, CLCNKB, and MAGED2 genes in probands 4, 5, and 6. CONCLUSIONS: Genetic analysis identified loss-of-function variants in the SLC12A1, KCNJ1, and CLCNKB genes in four patients with ABS and in the CLCNKB gene in two patients with CBS.


Assuntos
Síndrome de Bartter , Humanos , Feminino , Gravidez , Síndrome de Bartter/genética , Homozigoto , Deleção de Sequência , Heterozigoto , Mutação , Antígenos de Neoplasias , Proteínas Adaptadoras de Transdução de Sinal , Canais de Cloreto/genética
7.
Nefrologia (Engl Ed) ; 43(4): 484-490, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37775346

RESUMO

Primary distal renal tubular acidosis (dRTA) is a rare tubulopathy characterised by the presence of hyperchloremic metabolic acidosis. It is caused by the existence of a defect in the function of the H+ -ATPase located on the luminal side of the α-intercalated cells or the Cl - HCO3- (AE1) anion exchanger located on the basolateral side. Patients do not acidify the urine after acid overload (NH4Cl) or after stimulating H+ secretion by obtaining a high intratubular concentration of an anion such as chlorine (pH is measured) or HCO3- (urinary pCO2 is measured). We present a family with autosomal dominant dRTA produced by a heterozygous mutation in the SLC4A1 gene in which the two paediatric members showed a test of normal maximum urinary pCO2. Our hypothesis is that since the H + -ATPase is intact, at least initially, the stimulation induced by intratubular electronegativity to secrete H + could be effective, which would allow the maximum urinary pCO2 to be paradoxically normal, which could explain the onset, moderate presentation of symptoms and late diagnosis in patients with this mutation. This is the first documented case of a dominant dRTA in Mexico.


Assuntos
Acidose Tubular Renal , Humanos , Criança , Acidose Tubular Renal/diagnóstico , Acidose Tubular Renal/genética , Proteína 1 de Troca de Ânion do Eritrócito/genética , Mutação , Ânions/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo
8.
Complement Ther Clin Pract ; 49: 101639, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35841719

RESUMO

BACKGROUND: Mindfulness interventions can improve psychological distress and quality of life (QoL) in cancer survivors. Few mindfulness programs for cancer recovery exist in Southeastern U.S. The primary objective of this study was to assess the feasibility of a modified mindfulness-based stress reduction (MBSR) program for breast cancer patients in Birmingham, Alabama. The secondary objective was to explore potential program effects on mindfulness skills and QoL. METHODS: This study was a prospective, quasi-experimental feasibility study conducted over 10 months at a university hospital. Feasibility was achieved if 80% of eligible patients screened enrolled in the study and 70% of enrolled patients attended all 8 program sessions. Effectiveness was estimated by changes in mindfulness and QoL indicators measured with validated scales administered at 3 time points and assessed with a non-parametric Friedman test. Sessions included meditation, yoga, and an attention practice called body scan. There were 3 groups of 2-5 patients. RESULTS: The sample totaled 12 patients. Forty-four percent (12/27) of eligible patients enrolled in the study, and two out of 12 enrolled patients completed 8 program sessions, resulting in 16.7% (2/12) retention. However, more than half (66.7%) of participants completed at least 7 sessions. Between baseline and 8-week follow-up, patients demonstrated statistically significant improvements in distress, general wellbeing, and fatigue-related QoL. CONCLUSIONS: Feasibility objectives were not achieved. However, a majority of participants (66.7%) completed 7 of 8 program sessions. Program effects were promising for distress, fatigue, and wellbeing. Results warrant further research on MBSR-like programs for breast cancer patients in Alabama.


Assuntos
Neoplasias da Mama , Meditação , Atenção Plena , Feminino , Humanos , Neoplasias da Mama/terapia , Neoplasias da Mama/psicologia , Fadiga/terapia , Estudos de Viabilidade , Atenção Plena/métodos , Estudos Prospectivos , Qualidade de Vida/psicologia , Estresse Psicológico/terapia , Resultado do Tratamento , Alabama
9.
Front Immunol ; 13: 1057499, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36389760

RESUMO

Polyhedrins are viral proteins present in a large family of baculoviruses that form occlusion bodies (polyhedra). These structures protect the virus particles from the outside environment until they are ingested by susceptible insects. Occluded viruses can sustain inclement weather for long periods of time. Therefore, the polyhedra is a natural preservative that keeps the viral structure intact at ambient temperature for years. In a previous study we identified the first 110 amino acids from polyhedrin (PH(1-110)) as a good candidate to carry antigens of interest. As a proof of concept, we produced a fusion protein with PH(1-110) and the green fluorescent protein (PH(1-110)GFP). The fusion protein associates spontaneously during its synthesis resulting in the formation of nanoparticles. Nasal immunization with these nanoparticles and in the absence of any adjuvant, results in a robust immune response with the production of IgG immunoglobulins that remained elevated for months and that selectively recognize the GFP but not PH(1-110). These results indicate that PH(1-110) is poorly immunogenic but capable of enhancing the immune response to GFP.


Assuntos
Nanopartículas , Vacinas , Temperatura , Antígenos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo
10.
Resuscitation ; 170: 63-69, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34793874

RESUMO

OBJECTIVES: Resuscitation in the Head Up position improves outcomes in animals treated with active compression decompression cardiopulmonary resuscitation and an impedance threshold device (ACD + ITD CPR).We assessed impact of time to deployment of an automated Head Up position (AHUP) based bundle of care after out-of-hospital cardiac arrest on return of spontaneous circulation (ROSC). METHODS: Observational data were analyzed from a patient registry. Patients received treatment with 1) ACD + and/or automated CPR 2) an ITD and 3) an AHUP device. Probability of ROSC (ROSCprob) from the 9-1-1 call to AHUP device placement was assessed with a restricted cubic spline model and linear regression. RESULTS: Of 11 sites, 6 recorded the interval from 9-1-1 to AHUP device (n = 227). ROSCprobfor all rhythms was 34%(77/227). Median age (range) was 66 years (19-101) and 68% men. TheROSCprobfor shockable rhythms was 47%(18/38). Minutes from 9-1-1 to AHUP device (median, range) varied between sites: 1) 6.4(4,15), 2) 8.0(5,19), 3) 9.9(4, 12), 4) 14.1(6, 36), 5) 15.9(6, 34), 6) 19.0(8, 38),(p = 0.0001).ROSCprobalso varied; 1) 55.1%(16/29), 2) 60%(3/5), 3) 50%(3/6), 4) 22.7%(17/75), 5) 26.4%(9/34), and 6) 37.1%(29/78), (p = 0.019). For all rhythms between 4 and 12 min (n = 85),ROSCprobdeclined 5.6% for every minute elapsed (p = 0.024). For shockable rhythms, between 6 and 15 min (n = 23),ROSCprobdeclined 9.0% for every minute elapsed (p = 0.006). CONCLUSIONS: Faster time to deployment of an AHUP based bundle of care is associated with higher incidence of ROSC. This must be considered when evaluating and implementing this bundle.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca Extra-Hospitalar , Humanos , Parada Cardíaca Extra-Hospitalar/terapia , Probabilidade , Retorno da Circulação Espontânea , Tórax
11.
Kidney Int ; 80(8): 832-40, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21796099

RESUMO

Recent studies have identified Rhesus proteins as important molecules for ammonia transport in acid-secreting intercalated cells in the distal nephron. Here, we provide evidence for an additional molecule that can mediate NH3/NH4 excretion, the subtype 2 of the hyperpolarization-activated cyclic nucleotide-gated channel family (HCN2), in collecting ducts in rat renal cortex and medulla. Chronic metabolic acidosis in rats did not alter HCN2 protein expression but downregulated the relative abundance of HCN2 mRNA. Its cDNA was identical to the homolog from the brain and the protein was post-translationally modified by N-type glycosylation. Electrophysiological recordings in Xenopus oocytes injected with HCN2 cRNA found that potassium was transported better than ammonium, each of which was transported significantly better than sodium, criteria that are compatible with a role for HCN2 in ammonium transport. In microperfused rat outer medullary collecting duct segments, the initial rate of acidification, upon exposure to a basolateral ammonium chloride pulse, was higher in intercalated than in principal cells. A specific inhibitor of HCN2 (ZD7288) decreased acidification only in intercalated cells from control rats. In rats with chronic metabolic acidosis, the rate of acidification doubled in both intercalated and principal cells; however, ZD7288 had no significant inhibitory effect. Thus, HCN2 is a basolateral ammonium transport pathway of intercalated cells and may contribute to the renal regulation of body pH under basal conditions.


Assuntos
Canais Iônicos/fisiologia , Túbulos Renais Distais/metabolismo , Compostos de Amônio Quaternário/metabolismo , Acidose/metabolismo , Animais , Transporte Biológico , Imunofluorescência , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Canais Iônicos/análise , Túbulos Renais/metabolismo , Canais de Potássio , Ratos
12.
Resuscitation ; 158: 220-227, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33027619

RESUMO

AIM OF THE STUDY: Controlled sequential elevation of the head and thorax (CSE) during active compression decompression (ACD) cardiopulmonary resuscitation (CPR) with an impedance threshold device (ITD) has been shown to increase cerebral perfusion pressure and cerebral blood flow in previous animal studies as compared to the traditional supine position. The potential for this novel bundled treatment strategy to improve survival with intact neurological function is unknown. METHODS: Female farm pigs were sedated, intubated, and anesthetized. Central arterial and venous access were continuously monitored. Regional brain tissue perfusion (CerO2) was also measured transcutaneous. Ventricular fibrillation (VF) was induced and untreated for 10 min. Pigs were randomized to (1) Conventional CPR (C-CPR) flat or (2) ACD + ITD CSE CPR that included 2 min of ACD + ITD with the head and heart first elevated 10 and 8 cm, and then gradual elevation over 2 min to 22 and 9 cm, respectively. After 19 min of CPR, pigs were defibrillated and recovered. A veterinarian blinded to the intervention assessed cerebral performance category (CPC) at 24 h. A neurologically intact outcome was defined as a CPC score of 1 or 2. Categorical outcomes were analyzed by Fisher's exact test and continuous outcomes with an unpaired student's t-test. RESULTS: In 16 animals, return of spontaneous circulation rate was 8/8 (100%) with ACD + ITD CSE and 3/8 (25%) for C-CPR (p = 0.026). For the primary outcome of neurologically intact survival, 6/8 (75%) pigs had a CPC score 1 or 2 with ACD + ITD CSE versus 1/8 (12.5%) with C-CPR (p = 0.04). Coronary perfusion pressure (mmHg, mean ±â€¯SD) was higher with CSE at 18 min (41 ±â€¯24 versus 10 ±â€¯5, p = 0.004). rSO2 (%, mean ±â€¯SD) and ETCO2 (mmHg, mean ±â€¯SD) values were higher at 18 min with CSE (32 ±â€¯9 versus 17 ±â€¯2, p = 0.01, and 55 mmHg ±â€¯10 versus 21 mmHg ±â€¯4, p < 0.001), respectively. CONCLUSIONS: The novel bundled resuscitation approach of CSE with ACD + ITD CPR increased favorable neurological survival versus C-CPR in a swine model of cardiac arrest.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Animais , Feminino , Descompressão , Impedância Elétrica , Parada Cardíaca/terapia , Suínos , Tórax
13.
FEBS Open Bio ; 11(4): 1093-1108, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33565726

RESUMO

G protein-activated inward-rectifying potassium (K+ ) channels (Kir3/GIRK) participate in cell excitability. The GIRK5 channel is present in Xenopus laevis oocytes. In an attempt to investigate the physiological role of GIRK5, we identified a noncanonical di-arginine endoplasmic reticulum (ER) retention motif (KRXY). This retention motif is located at the N-terminal region of GIRK5, coded by two small exons found only in X. laevis and X. tropicalis. These novel exons are expressed through use of an alternative transcription start site. Mutations in the sequence KRXY produced functional channels and induced progesterone-independent oocyte meiotic progression. The chimeric proteins enhanced green fluorescent protein (EGFP)-GIRK5-WT and the EGFP-GIRK5K13AR14A double mutant, were localized to the ER and the plasma membrane of the vegetal pole of the oocyte, respectively. Silencing of GIRK5 or blocking of this channel by external barium prevented progesterone-induced meiotic progression. The endogenous level of GIRK5 protein decreased through oocyte stages in prophase I augmenting by progesterone. In conclusion, we have identified a unique mechanism by which the expression pattern of a K+ channel evolved to control Xenopus oocyte maturation.


Assuntos
Motivos de Aminoácidos , Sequência de Aminoácidos , Retículo Endoplasmático/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/química , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Oócitos/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas de Xenopus/química , Proteínas de Xenopus/metabolismo , Animais , Sequência Conservada , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Humanos , Oócitos/efeitos dos fármacos , Filogenia , Ligação Proteica , Proteínas de Xenopus/genética , Xenopus laevis
14.
Resuscitation ; 159: 45-53, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33385469

RESUMO

AIM: The optimal head and thorax position after return of spontaneous circulation (ROSC) following cardiac arrest (CA) is unknown. This study examined whether head and thorax elevation post-ROSC is beneficial, in a porcine model. METHODS: Protocol A: 40 kg anesthetized pigs were positioned flat, after 7.75 min of untreated CA the heart and head were elevated 8 and 12 cm, respectively, above the horizontal plane, automated active compression decompression (ACD) plus impedance threshold device (ITD) CPR was started, and 2 min later the heart and head were elevated 10 and 22 cm, respectively, over 2 min to the highest head up position (HUP). After 30 min of CPR pigs were defibrillated and randomized 10 min later to four 5-min epochs of HUP or flat position. Multiple physiological parameters were measured. In Protocol B, after 6 min of untreated VF, pigs received 6 min of conventional CPR flat, and after ROSC were randomized HUP versus Flat as in Protocol A. The primary endpoint was cerebral perfusion pressure (CerPP). Multivariate analysis-of-variance (MANOVA) for repeated measures was used. Data were reported as mean ±â€¯SD. RESULTS: In Protocol A, intracranial pressure (ICP) (mmHg) was significantly lower post-ROSC with HUP (9.1 ±â€¯5.5) versus Flat (18.5 ±â€¯5.1) (p < 0.001). Conversely, CerPP was higher with HUP (62.5 ±â€¯19.9) versus Flat (53.2 ±â€¯19.1) (p = 0.004), respectively. Protocol A and B results comparing HUP versus Flat were similar. CONCLUSION: Post-ROSC head and thorax elevation in a porcine model of cardiac arrest resulted in higher CerPP and lower ICP values, regardless of VF duration or CPR method. IACUC PROTOCOL NUMBER: 19-09.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca , Animais , Circulação Cerebrovascular , Modelos Animais de Doenças , Parada Cardíaca/terapia , Suínos , Tórax
15.
Am J Physiol Renal Physiol ; 299(1): F255-64, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20427469

RESUMO

The fine regulation of Na(+) and K(+) transport takes place in the cortical distal nephron. It is well established that K(+) secretion occurs through apical K(+) channels: the ROMK and the Ca(2+)- and voltage-dependent maxi-K. Previously, we identified the voltage-gated Kv1.3 channel in the inner medulla of the rat kidney (Escobar LI, Martínez-Téllez JC, Salas M, Castilla SA, Carrisoza R, Tapia D, Vázquez M, Bargas J, Bolívar JJ. Am J Physiol Cell Physiol 286: C965-C974, 2004). To examine the role of Kv1.3 in the renal regulation of K(+) homeostasis, we characterized the effect of dietary K(+) on the molecular and functional expression of this channel. We performed real-time-PCR and immunoblot assays in kidneys from rats fed a control (CK; 1.2% wt/wt) or high-K(+) (HK; 10% wt/wt) diet for 5-15 days. Kv1.3 mRNA and protein expression did not change with HK in the whole kidney. However, dietary K(+) loading provoked a change in the cellular distribution of Kv1.3 from the cytoplasm to apical membranes. Immunolocalization of Kv1.3 detected the channel exclusively in the intercalated cells. We investigated whether Kv1.3 mediated K(+) transport in microperfused cortical collecting ducts (CCDs). The HK diet led to an increase in net K(+) transport from 7.4 +/- 1.1 (CK) to 11.4 +/- 1.0 (HK) pmol x min(-1.) mm(-1). Luminal margatoxin, a specific blocker of Kv1.3, decreased net K(+) secretion in HK CCDs to 6.0 +/- 1.6 pmol x min(-1.) mm(-1). Our data provide the first evidence that Kv1.3 channels participate in K(+) secretion and that apical membrane localization of Kv1.3 is enhanced in the intercalated cells by dietary K(+) loading.


Assuntos
Ativação do Canal Iônico , Rim/metabolismo , Canal de Potássio Kv1.3/metabolismo , Potássio na Dieta/metabolismo , Animais , Western Blotting , Homeostase , Concentração de Íons de Hidrogênio , Imuno-Histoquímica , Rim/citologia , Rim/efeitos dos fármacos , Cinética , Canal de Potássio Kv1.3/antagonistas & inibidores , Canal de Potássio Kv1.3/genética , Masculino , Potenciais da Membrana , Microscopia de Fluorescência , Perfusão , Bloqueadores dos Canais de Potássio/farmacologia , Potássio na Dieta/urina , Transporte Proteico , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Venenos de Escorpião/farmacologia , Fatores de Tempo , Urinálise
16.
Histochem Cell Biol ; 133(2): 189-99, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19921238

RESUMO

Potassium (K(+)) channels participate in K(+) secretion, K(+) recycling, and cell volume regulation and help to maintain the resting potential in mammalian kidneys. Previously, we identified a set of voltage-gated K(+) channels (Kv1) in the inner medullary collecting duct of the rat kidney. In the present work, we identified the voltage-gated K(+) channel ether-à-go-go-related gene (ERG) in the rat kidney. mRNAs of ERG1a and its N-terminal splice-variant ERG1b were detected. Immunoblots of the cortex and medulla revealed two molecular mass proteins of 135 and 80 kDa, consistent in size with the nonglycosylated ERG1a and ERG1b isoforms, respectively. However, bands of 155 and 95 kDa, corresponding to mature glycosylated ERG1a and ERG1b, respectively, were also observed. In our immunohistochemical experiments, we could not differentiate the ERG1 isoforms because we used an antibody against a carboxy-terminal epitope. ERG1 was differentially localized in specific nephron segments: its localization was intracellular in the proximal tubule and medullary collecting ducts and in the apical membranes in the distal convoluted and connecting tubules. ERG1 was also abundant in glomerular arterioles and renal vessels. In summary, ERG1 displays a heterogeneous distribution in the rat kidney.


Assuntos
Canais de Potássio Éter-A-Go-Go/biossíntese , Rim/ultraestrutura , Animais , Canal de Potássio ERG1 , Imunofluorescência , Rim/citologia , Masculino , Ratos , Ratos Wistar
18.
J Mol Histol ; 51(6): 701-716, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33070272

RESUMO

The kidney controls body fluids, electrolyte and acid-base balance. Previously, we demonstrated that hyperpolarization-activated and cyclic nucleotide-gated (HCN) cation channels participate in ammonium excretion in the rat kidney. Since acid-base balance is closely linked to potassium metabolism, in the present work we aim to determine the effect of chronic metabolic acidosis (CMA) and hyperkalemia (HK) on protein abundance and localization of HCN3 in the rat kidney. CMA increased HCN3 protein level only in the outer medulla (2.74 ± 0.31) according to immunoblot analysis. However, immunofluorescence assays showed that HCN3 augmented in cortical proximal tubules (1.45 ± 0.11) and medullary thick ascending limb of Henle's loop (4.48 ± 0.45) from the inner stripe of outer medulla. HCN3 was detected in brush border membranes (BBM) and mitochondria of the proximal tubule by immunogold electron and confocal microscopy in control conditions. Acidosis did not alter HCN3 levels in BBM and mitochondria but augmented them in lysosomes. HCN3 was also immuno-detected in mitoautophagosomes. In the distal nephron, HCN3 was expressed in principal and intercalated cells from cortical to medullary collecting ducts. CMA did not change HCN3 abundance in these nephron segments. In contrast, HK doubled HCN3 level in cortical collecting ducts and favored its basolateral localization in principal cells from the inner medullary collecting ducts. These findings further support HCN channels contribution to renal acid-base and potassium balance.


Assuntos
Acidose/etiologia , Acidose/metabolismo , Hiperpotassemia/etiologia , Hiperpotassemia/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Néfrons/metabolismo , Canais de Potássio/metabolismo , Animais , Biomarcadores , Doença Crônica , Células Epiteliais/metabolismo , Imunofluorescência/métodos , Expressão Gênica , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Túbulos Renais Proximais/metabolismo , Alça do Néfron/metabolismo , Néfrons/ultraestrutura , Canais de Potássio/genética , Ratos
19.
Res Social Adm Pharm ; 16(8): 1003-1016, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31812499

RESUMO

BACKGROUND: Patients' views on the optimal model for care coordination between primary care providers (PCPs) and oncologists in the context of cancer and multiple chronic conditions (MCC) are unclear. Thus, the purpose of this systematic review is to evaluate the perceptions of patients with both cancer and MCC regarding their care coordination needs. METHODS: Following PRISMA guidelines, the literature was systematically searched through PubMed, CINAHL, and PsycINFO for articles pertaining to patients' perspectives, experiences, and needs regarding care coordination between PCPs and oncologists during the cancer care continuum, in the context of patients with cancer and MCC. English-language articles were included if they met the following criteria: 1) published between 2008 and 2018; 2) peer-reviewed study; 3) patients aged 18 years or older diagnosed with any type or stage of cancer; 4) patients have one or more chronic comorbid condition; 5) inclusion of patient perceptions, experiences, or needs related to care coordination between PCPs and oncologists; and 6) ability to extract results. Data extraction was performed with a standardized form, and themes were developed through qualitative synthesis. A grounded theory approach was used to qualitatively evaluate data extracted from articles and create a framework for providers to consider when developing patient-centered care coordination strategies for these complex patients. Risk of bias within each study was assessed independently by two authors using the Mixed Methods Appraisal Tool. RESULTS: A total of 22 articles were retained, representing the perspectives of 8,114 patients with cancer and MCC. Studies were heterogeneous in the patients' respective phases of cancer care and study design. From qualitative synthesis, four themes emerged regarding patients' needs for cancer care coordination and were included as constructs to develop the Patient-centered Care Coordination among Patients with Multiple Chronic Conditions and Cancer (PCP-MC) framework. Constructs included: 1) Communication; 2) Defining provider care roles; 3) Information access; and 4) Individualized patient care. Care navigators served as a communication bridge between providers and patients. CONCLUSIONS: Findings highlight the importance that patients with both cancer and MCC place on communication with and between providers, efficient access to understandable care information, defined provider care roles, and care tailored to their individual needs and circumstances. Providers and policymakers may consider the developed PCP-MC framework when designing, implementing, and evaluating patient-centered care coordination strategies for patients with both cancer and MCC.


Assuntos
Neoplasias , Atenção Primária à Saúde , Comunicação , Pessoal de Saúde , Humanos , Neoplasias/terapia , Assistência Centrada no Paciente
20.
Data Brief ; 33: 106473, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33204782

RESUMO

The presence of microplastics in marine and coastal environments is an issue of concern for the preservation of these ecosystems. This dataset provides the results of the first national assessment of the presence of microplastics (<5 mm) in Mexican beaches. The research included 35 beaches along the five marine regions of the country. For each beach, ten samples (19 cm diameter, 5 cm depth) were taken along the high-tide line, and then microplastics were extracted by flotation and sieving. All the plastic particles were quantified and classified based on their colour, type of particle, and type of plastic used in their production, using visual inspection and FTIR spectroscopy. The use of the same methodology in all the beaches allowed us to compare and analyze the results, which are reported in the article Microplastics in Mexican beaches.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa