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1.
BMC Med Educ ; 22(1): 773, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36357937

RESUMO

BACKGROUND: The global spread of the COVID-19 virus caused unprecedented interruptions in medical education. This paper evaluates Relational Coordination (RC): communicating and relating for task integration; between the distinct stakeholders responsible for scheduling,delivering and receiving clinical teaching in the wake of the pandemic. METHODOLOGY: Using a cross-sectional design, the level of Relational Coordination was assessed between twelve groups within a Clinical Skills Program at a Medical School in the United Arab Emirates. It also measures three relevant mental health factors: namely, Job satisfaction, Work Engagement, and Burnout. RESULTS: Overall, RC scores were moderate (3.65 out of 5.00). Controlling for participants' position, RC was found to positively and significantly increase both job satisfaction (ß = 1.10, p < 0.001) and work engagement (ß = 0.78, p < 0.01)., Additionally, RC was significantly associated with lower burnout (ß = -0.56, p = 0.05). Fifty percent of participants experienced high job satisfaction, with a mean score of 5.0 out of 7.0, while 73% reported being enthusiastic about their job, with a mean score of 6.0 out of 7.0. About a third of participants (27%) reported feeling burnout. CONCLUSIONS: During times of disruption and crisis, medical education can benefit from higher levels of relational coordination. Our study shows the significant impact of relational coordination on mental health measures like job satisfaction and work engagement. To achieve the full potential and benefits of excellent levels of relational coordination in this program, we recommend six interventions focusing on improving communication, work processes, regular meetings, education innovations, capacity building, and the establishment of coaching and counseling programs for students and faculty.


Assuntos
Esgotamento Profissional , COVID-19 , Humanos , Saúde Mental , Pandemias , COVID-19/epidemiologia , Competência Clínica , Estudos Transversais , Satisfação no Emprego , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/prevenção & controle , Esgotamento Profissional/etiologia , Estudantes , Inquéritos e Questionários
2.
Artigo em Inglês | MEDLINE | ID: mdl-26069529

RESUMO

The purpose of this in vitro study was to develop a useful biomarker (e.g., cellular respiration, or mitochondrial O2 consumption) for measuring activities of mTOR inhibitors. It measured the effects of commonly used immunosuppressants (sirolimus - rapamycin, tacrolimus, and cyclosporine) on cellular respiration in target tissues (kidney, liver, and heart) from C57BL/6 mice. The mammalian target of rapamycin (mTOR), a serine/threonine kinase that supports nutrient-dependent cell growth and survival, is known to control energy conversion processes within the mitochondria. Consistently, inhibitors of mTOR (e.g., rapamycin, also known as sirolimus or Rapamune®) have been shown to impair mitochondrial function. Inhibitors of the calcium-dependent serine/threonine phosphatase calcineurin (e.g., tacrolimus and cyclosporine), on the other hand, strictly prevent lymphokine production leading to a reduced T-cell function. Sirolimus (10 µM) inhibited renal (22%, p = 0.002), hepatic (39%, p < 0.001), and cardiac (42%, p = 0.005) cellular respiration. Tacrolimus and cyclosporine had no or minimum effects on cellular respiration in these tissues. Thus, these results clearly demonstrate that impaired cellular respiration (bioenergetics) is a sensitive biomarker of the immunosuppressants that target mTOR.

3.
Int J Clin Exp Pathol ; 8(3): 2955-62, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26045804

RESUMO

The purpose of this in vitro study was to develop a useful biomarker (e.g., cellular respiration, or mitochondrial O2 consumption) for measuring activities of mTOR inhibitors. It measured the effects of commonly used immunosuppressants (sirolimus-rapamycin, tacrolimus, and cyclosporine) on cellular respiration in target tissues (kidney, liver, and heart) from C57BL/6 mice. The mammalian target of rapamycin (mTOR), a serine/ threonine kinase that supports nutrient-dependent cell growth and survival, is known to control energy conversion processes within the mitochondria. Consistently, inhibitors of mTOR (e.g., rapamycin, also known as sirolimus or Rapamune®) have been shown to impair mitochondrial function. Inhibitors of the calcium-dependent serine/threonine phosphatase calcineurin (e.g., tacrolimus and cyclosporine), on the other hand, strictly prevent lymphokine production leading to a reduced T-cell function. Sirolimus (10 µM) inhibited renal (22%, P=0.002), hepatic (39%, P<0.001), and cardiac (42%, P=0.005) cellular respiration. Tacrolimus and cyclosporine had no or minimum effects on cellular respiration in these tissues. Thus, these results clearly demonstrate that impaired cellular respiration (bioenergetics) is a sensitive biomarker of the immunosuppressants that target mTOR.


Assuntos
Respiração Celular/efeitos dos fármacos , Imunossupressores/farmacologia , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Animais , Coração/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos
4.
Int J Clin Exp Pathol ; 8(1): 81-95, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25755695

RESUMO

BACKGROUND: Cisplatin, carboplatin and oxaliplatin are structurally-related compounds, which are commonly used in cancer therapy. Cisplatin (Platinol(®)) has Boxed Warning stating: "Cumulative renal toxicity associated with PLATINOL is severe", while carboplatin and oxaliplatin are less nephrotoxic. These drugs form platinum adducts with cellular DNA. Their bindings to cellular thiols (e.g., glutathione and metallothionein) are known to contribute to drug resistance while thiol depletion augments platinum toxicity. METHODS: Using phosphorescence oxygen analyzer, this study investigated the effects of platinum drugs on renal cellular respiration (mitochondrial O2 consumption) in the presence and absence of the thiol blocking agent N-ethylmaleimide (used here as a model for thiol depletion). Renal cellular ATP was also determined. Kidney fragments from C57BL/6 mice were incubated at 37 °C in Krebs-Henseleit buffer (gassed with 95% O2:5% CO2) with and without 100 µM platinum drug in the presence and absence of 100 µM N-ethylmaleimide for ≤ 6 h. RESULTS: Platinum drugs alone had no effects on cellular respiration (P ≥ 0.143) or ATP (P ≥ 0.161). N-ethylmaleimide lowered cellular respiration (P ≤ 0.114) and ATP (P = 0.008). The combination of platinum drug and N-ethylmaleimide significantly lowered both cellular respiration (P ≤ 0.006) and ATP (P ≤ 0.003). Incubations with N-ethylmaleimide alone were associated with moderate-to-severe tubular necrosis. Incubations with cisplatin+N-ethylmaleimide vs. cisplatin alone produced similar severities of tubular necrosis. Tubular derangements were more prominent in carboplatin+N-ethylmaleimide vs. carboplatin alone and in oxaliplatin+N-ethylmaleimide vs. oxaliplatin alone. CONCLUSIONS: These results demonstrate the adverse events of thiol depletion on platinum-induced nephrotoxicities. The results suggest cellular bioenergetics is a useful surrogate biomarker for assessing drug-induced nephrotoxicities.


Assuntos
Antineoplásicos/toxicidade , Respiração Celular/efeitos dos fármacos , Rim/efeitos dos fármacos , Compostos de Platina/toxicidade , Animais , Etilmaleimida/farmacologia , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Compostos de Sulfidrila/metabolismo , Reagentes de Sulfidrila/farmacologia
5.
World J Gastroenterol ; 21(2): 644-52, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25593494

RESUMO

AIM: To measure biochemical parameters in stomach biopsies and test their suitability as diagnostic biomarkers for gastritis and precancerous lesions. METHODS: Biopsies were obtained from the stomachs of two groups of patients (n = 40) undergoing fiber-optic endoscopy due to upper gastrointestinal symptoms. In the first group (n = 17), only the corpus region was examined. Biopsies were processed for microscopic examination and measurement of mitochondrial O2 consumption (cellular respiration), cellular adenosine triphosphate (ATP), glutathione (GSH), and caspase activity. In the second group of patients (n = 23), both corpus and antral regions were studied. Some biopsies were processed for microscopic examination, while the others were used for measurements of cellular respiration and GSH level. RESULTS: Microscopic examinations of gastric corpus biopsies from 17 patients revealed normal mucosae in 8 patients, superficial gastritis in 7 patients, and chronic atrophic gastritis in 1 patient. In patients with normal histology, the rate (mean ± SD) of cellular respiration was 0.17 ± 0.02 µmol/L O2 min(-1) mg(-1), ATP content was 487 ± 493 pmol/mg, and GSH was 469 ± 98 pmol/mg. Caspase activity was detected in 3 out of 8 specimens. The values of ATP and caspase activity were highly variable. The presence of superficial gastritis had insignificant effects on the measured biomarkers. In the patient with atrophic gastritis, cellular respiration was high and ATP was relatively low, suggesting uncoupling oxidative phosphorylation. In the second cohort of patients, the examined biopsies showed either normal or superficial gastritis. The rate of cellular respiration (O2. µmol/L min(-1) mg(-1)) was slightly higher in the corpus than the antrum (0.18 ± 0.05 vs 0.15 ± 0.04, P = 0.019). The value of GSH was about the same in both tissues (310 ± 135 vs 322 ± 155, P = 0.692). CONCLUSION: The corpus mucosa was metabolically more active than the antrum tissue. The data in this study will help in understanding the pathophysiology of gastric mucosa.


Assuntos
Caspases/metabolismo , Metabolismo Energético , Gastrite Atrófica/enzimologia , Glutationa/metabolismo , Estômago/enzimologia , Trifosfato de Adenosina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Biomarcadores/metabolismo , Biópsia , Respiração Celular , Endoscopia Gastrointestinal , Estudos de Viabilidade , Feminino , Mucosa Gástrica/enzimologia , Gastrite Atrófica/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Valor Preditivo dos Testes , Estudos Prospectivos , Antro Pilórico/enzimologia , Estômago/patologia , Adulto Jovem
6.
BMC Pharmacol Toxicol ; 14: 15, 2013 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-23448291

RESUMO

Atorvastatin (a 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor) is a widely used cholesterol-lowering drug, which is recognized for its potential hepatotoxicity. This study investigated in vitro effects of this agent on hepatic tissue respiration, ATP content, caspase activity, urea synthesis and histology. Liver fragments from Taylor Outbred and C57Bl/6 mice were incubated at 37°C in Krebs-Henseleit buffer continuously gassed with 95% O2: 5% CO2 in the presence and absence of atorvastatin. Phosphorescence O2 analyzer that measured dissolved [O2] as a function of time was used to monitor cellular mitochondrial O2 consumption. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin was used to monitor caspase activity. The rates of hepatocyte respiration (µM O2 min(-1) mg(-1)) in untreated samples were 0.15±0.07 (n=31). The corresponding rates for samples treated with 50 nM (therapeutic concentration), 150 nM or 1.0 µM atorvastatin for ≤13 h were 0.13±0.05 (n=19), p=0.521. The contents of hepatocyte ATP (pmol(-1) mg(-1)) in untreated samples were 40.3±14.0 and in samples treated with 1.0 µM atorvastatin for ≤4.5 h were 48.7±23.9 (p=0.7754). The concentrations of urea (mg/dL mg(-1), produced over 50 min) for untreated samples were 0.061±0.020 (n=6) and for samples treated with 1.0 µM atorvastatin for ≤6 h were 0.072±0.022 (n=6), p=0.3866. Steadily, hepatocyte caspase activity and histology were unaffected by treatments with up to 1.0 µM atorvastatin for ≤6 h. Thus, the studied murine model showed preserved hepatocyte function and structure in the presence of high concentrations of atorvastatin.


Assuntos
Hepatócitos/efeitos dos fármacos , Ácidos Heptanoicos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Fígado/efeitos dos fármacos , Pirróis/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Atorvastatina , Caspases/metabolismo , Metabolismo Energético , Hepatócitos/metabolismo , Técnicas In Vitro , Fígado/anatomia & histologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/metabolismo , Ureia/metabolismo
7.
BMC Res Notes ; 6: 70, 2013 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-23442607

RESUMO

BACKGROUND: The aim of this study was to develop liver tissue preparation suitable for investigating toxins. Hepatocyte respiration, ATP content, urea synthesis, caspase activity and morphology were measured as a function of in vitro incubation time. Mice were anesthetized by sevoflurane inhalation. Small liver fragments were then rapidly excised and incubated at 37°C in Krebs-Henseleit buffer (continuously gassed with 95% O2: 5% CO2) for up to 6 h. Phosphorescence O2 analyzer was used to determine the rate of cellular mitochondrial O2 consumption (kc, µM O2 min-1 mg-1). Cellular ATP was measured using the luciferin/luciferase system. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspase activity; cleaved AMC moieties (reflecting caspase activity) were separated on HPLC and detected by fluorescence. FINDINGS: Respiration was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. The values of kc (mean ± SD) for 0≤ t ≤6 h were 0.15 ± 0.02 µM O2 min-1 mg-1 (n = 18, coefficient of variation, CV = 13%), ATP content 131 ± 69 pmol mg-1 (1≤ t ≤6 h, n = 16, CV = 53%), synthesized urea 0.134 ± 0.017 mg/dL mg-1 in 50 min (0≤ t ≤6 h, n = 14, CV = 13%), and AMC peak area 62,540 ± 26,227 arbitrary units mg-1 (1≤ t ≤6 h, n = 3, CV = 42%). Hepatocyte morphology and organelles were reasonably persevered. CONCLUSIONS: The described liver tissue preparation demonstrates stable hepatocyte structure, ultrastructure and biomarkers for up to 6 h, permitting in vitro studies.


Assuntos
Fígado/efeitos dos fármacos , Testes de Toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Caspase 3/metabolismo , Cromatografia Líquida de Alta Pressão , Metabolismo Energético , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias Hepáticas/metabolismo , Consumo de Oxigênio , Espectrometria de Fluorescência
8.
BMC Res Notes ; 6: 12, 2013 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-23311890

RESUMO

BACKGROUND: This study aimed to establish a suitable in vitro system for investigating effects of respiratory pathogens and toxins on lung tissue bioenergetics (cellular respiration and ATP content) and caspase activity. Wistar rats and C57Bl/6 mice were anesthetized by sevoflurane inhalation. Lung fragments were then collected and incubated at 37°C in a continuously gassed (with 95% O2:5% CO2) Minimal Essential Medium (MEM) or Krebs-Henseleit buffer. Phosphorescence O2 analyzer that measured dissolved O2 concentration as a function of time was used to monitor the rate of cellular mitochondrial O2 consumption. Cellular ATP content was measured using the luciferin/luciferase system. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspase activity; cleaved AMC moieties (reflecting caspase activity) were separated on HPLC and detected by fluorescence. Lung histology and immunostaining with anti-cleaved caspase-3 antibody were also performed. RESULTS: For Wistar rats, the values of kc and ATP for 0 < t ≤ 7 h (mean ± SD) were 0.15 ± 0.02 µM O2 min-1 mg-1 (n = 18, coefficient of variation, Cv = 13%) and 131 ± 69 pmol mg-1 (n = 16, Cv = 53%), respectively. The AMC peak areas remained relatively small despite a ~5-fold rise over 6 h. Good tissue preservation was evident despite time-dependent increases in apoptotic cells. Lung tissue bioenergetics, caspase activity and structure were deleterious in unoxygenated or intermittently oxygenated solutions. Incubating lung tissue in O2 depleted MEM for 30 min or anesthesia by urethane had no effect on lung bioenergetics, but produced higher caspase activity. CONCLUSIONS: Lung tissue bioenergetics and structure could be maintained in vitro in oxygenated buffer for several hours and, thus, used as biomarkers for investigating respiratory pathogens or toxins.


Assuntos
Caspases/metabolismo , Metabolismo Energético , Pulmão/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Pulmão/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Ratos , Ratos Wistar
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