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1.
J Surg Res ; 294: 150-159, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37890274

RESUMO

INTRODUCTION: Surgical emergencies are time sensitive. Identifying patients who may benefit from preoperative goals of care discussions is critical to ensuring that operative intervention aligns with the patient's values. We sought to identify patient factors associated with acute changes in a patient's goals using code status change (CSC) as proxy. METHODS: A retrospective analysis of single-institution data for patients undergoing urgent laparotomy was performed. Patients were stratified based on whether a postoperative CSC occurred. Parametric, nonparametric, and regression analyses were used to identify variables associated with CSC. RESULTS: Of 484 patients, 13.8% (n = 67) had a postoperative CSC. Patients with postoperative CSC were older (65 versus 60 years, P < 0.001). Odds of CSC were significantly higher in patients who were transferred between facilities (odds ratio [OR] 2.1), had a higher Charlson Comorbidity Index (3-4: OR 3.9, 5+: OR 6.8), and had a higher quick sequential organ failure assessment score (2: OR 5.0; 3: OR 38.7). Patients with anemia (OR 1.9) and active cancer (OR 3.0) had higher odds of CSC. CONCLUSIONS: Timely intervention in emergency general surgery may result in high-risk interventions and subsequent complications that do not align with a patient's goals and values. Our analysis identified a subset of patients who undergo surgery and have a postoperative CSC leading to transition to comfort-focused care. In these patients, a pause in clinical momentum may help ensure operative intervention remains goal concordant.


Assuntos
Neoplasias , Complicações Pós-Operatórias , Humanos , Estudos Retrospectivos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Laparotomia , Fatores de Risco
2.
Surg Endosc ; 37(5): 3921-3925, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37036502

RESUMO

INTRODUCTION: Educating residents on laparoscopic operations requires direct teaching and deliberate practice. Attending surgeons are often systematic when performing surgery, which creates a challenge when instructing surgery residents. The aim of this study was to use cognitive task analysis to expand laparoscopic cholecystectomy into microsteps reflecting expert surgeon cognition (perceptions, assessments, decisions, etc.) throughout the operation such that these could be better formalized and conveyed to residents in educational materials or assessments and to attending surgeons as teaching scripts. MATERIALS AND METHODS: One surgeon, a surgical resident, and a human factors specialist conducted cognitive task analyses with three expert general surgeons and one hepatobiliary surgeon using semi-structured interviews. These interviews expanded an existing task model of laparoscopic cholecystectomy to specifically add patient safety aspects including injury prevention, risk management, and complication detection for each step. Interview analysis resulted in an expanded task diagram. RESULTS: Cognitive task analysis expanded the current laparoscopic cholecystectomy task model from 19 to 97 microsteps. In addition to microsteps, an additional major step was identified, the planning step or step zero. Steps with the greatest number of microsteps included dissection with 15 microsteps and intraoperative cholangiogram with 10 microsteps. DISCUSSION: Laparoscopic cholecystectomies are complex operations with multiple microsteps. Identification of these steps can lead to explicit strategies that can improve training of surgeons, with an end towards efficacy and safety. The identification of a planning step prior to beginning the operation is a significant finding that should arguably be included in all future cognitive task analyses regardless of operation or procedure, to emphasize to trainees what senior surgeons have learned through experience. These findings inform the development of interventions for surgical training and evaluation of competency.


Assuntos
Colecistectomia Laparoscópica , Internato e Residência , Laparoscopia , Humanos , Colecistectomia Laparoscópica/métodos , Segurança do Paciente , Cognição , Competência Clínica
3.
J Surg Res ; 289: 22-26, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37075607

RESUMO

INTRODUCTION: Pancreatic ductal adenocarcinoma has the lowest 5-y relative survival of all solid tumor malignancies. Palliative care can improve the quality of life of both patients and their caregivers. However, the utilization patterns of palliative care in patients with pancreatic cancer are unclear. METHODS: Pancreatic cancer patients who were diagnosed between October 2014 and December 2020 at the Ohio State University were identified. Palliative care and hospice utilization and referral patterns were assessed. RESULTS: Of the 1458 pancreatic cancer patients, 55% (n = 799) were male, median age at diagnosis was 65 y (interquartile range [IQR]: 58, 73), and most were Caucasian (n = 1302, 89%). Palliative care was utilized by 29% (n = 424) of the cohort, with the initial consultation obtained after an average of 6 ± 9 mo from diagnosis. Patients who received palliative care were younger (62 y, IQR: 55, 70 versus 67 y, IQR: 59, 73; P < 0.001) and more frequently members of racial and ethnic minorities (15% versus 9%; P < 0.001) versus those who did not receive palliative care. Among the 344 (24%) patients who received hospice care, 153 (44%) had no prior palliative care consultation. Patients referred to hospice care survived a median of 14 d (95% CI, 12-16) after hospice referral. CONCLUSIONS: Only 3 out of 10 patients with pancreatic cancer received palliative care at an average of 6 mo from initial diagnosis. More than two out of every five patients referred to hospice had no previous palliative care consultation. Efforts to understand the impact of improved integration of palliative care into pancreatic cancer programs are needed.


Assuntos
Cuidados Paliativos na Terminalidade da Vida , Neoplasias Pancreáticas , Assistência Terminal , Humanos , Masculino , Feminino , Qualidade de Vida , Cuidados Paliativos , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas
4.
Surg Infect (Larchmt) ; 23(9): 801-808, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36301537

RESUMO

Background: Necrotizing soft tissue infections (NSTIs) are life-threatening infections requiring prompt intervention. The Distressed Communities Index (DCI) is a comprehensive ranking of socioeconomic well-being based on zip code. We sought to identify the role of DCI in predicting mortality in NSTI, because it remains unknown. Patients and Methods: A retrospective, single-institution analysis of patients diagnosed with NSTI (2011-2020) requiring surgical intervention. The DCI is a composite score based on community-level factors: unemployment, education level, poverty rate, median income, business growth, and housing vacancies. The DCI scores were matched to the patient's zip code and stratification was performed using quintiles. Parametric and non-parametric analyses were performed to evaluate both the demographic and clinical characteristics. Multivariable regression analyses were performed to identify independent variables associated with outcomes. Results: Six hundred twenty patients met inclusion criteria. Ninety-day mortality was 12.4% (n = 77). Patients who died were more likely to be female (58.4%), older (median age 60.5 ± 11.3 years), have a body mass index (BMI) ≥30 (61.5%), have a higher Charlson Comorbidity Index (3; interquartile range [IQR], 2-7). After regression analysis, neither the composite DCI by quintile, nor the individual component scores, were found to correlate with mortality. Interestingly, underlying heart disease, hepatic dysfunction, and renal disease at baseline were found to significantly correlate with mortality from NSTI with p values <0.05. Conclusions: Socioeconomic status and insurance payer are championed for inclusion when constructing risk models, evaluating resource utilization, comparing hospitals, and determining patient management. The severity of community distress measured by DCI did not correlate with mortality for NSTI, despite contrasting evidence in other diseases. This finding is likely caused by a combination of both individual and community-level resources. This is highlighted by the recognition that comorbidities did correlate with mortality. The absence of DCI-related associations observed in this study warrants further investigation, as do mechanisms for the prevention of further organ dysfunction.


Assuntos
Fasciite Necrosante , Infecções dos Tecidos Moles , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Infecções dos Tecidos Moles/epidemiologia , Estudos Retrospectivos , Comorbidade
5.
Surg Infect (Larchmt) ; 23(5): 475-482, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35647892

RESUMO

Background: The impact of obesity on the pathogenesis and prognosis of necrotizing soft tissue infections (NSTIs) is unclear. The goal of this study was to characterize differences in NSTI presentation and outcomes by obesity status. Patients and Methods: A retrospective analysis of institutional data for patients diagnosed with NSTIs were identified (n = 619; 2011-2020). Patients were divided based on obesity (body mass index [BMI] ≥ 30 kg/m2) and non-obese (BMI <30 kg/m2). Primary outcomes included NSTI location, micro-organisms, and index hospitalization data. Multiple logistic regression was used to model predictors of in-hospital and 90-day mortality. Results: The obese cohort (n = 390; 63%) had higher rates of congestive heart failure and type 2 diabetes mellitus. There were no differences in length of stay, mortality, or discharge disposition between groups. A higher rate of respiratory failure was observed in the obese versus non-obese group (36.7% vs. 20.9%; p < 0.0005). The obese cohort was associated with perineal (40.8% vs. 27.0%) and torso NSTIs (20.9% vs. 15.8%; p < 0.005) but reduced staphylococcal (19.2% vs. 27.4%; p = 0.02) and group A streptococcal (2.6% vs. 6.5%; p = 0.03) infections, and increased polymicrobial infections. Class 2 obesity was a negative predictor for in-hospital mortality (odds ratio [OR], 0.1; 95% confidence interval [CI], 0.03-0.5) and 90-day mortality (OR, 0.3; 95% CI, 0.1-0.8), when adjusting for demographic data, type of infection, and baseline comorbidities. Conclusions: Necrotizing soft tissue infections in obesity may present with unique distributions and microbial characteristics. Class 2 obesity may exhibit a survival benefit compared with non-obese patients, suggestive of an obesity paradox.


Assuntos
Diabetes Mellitus Tipo 2 , Infecções dos Tecidos Moles , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/complicações , Humanos , Obesidade/complicações , Obesidade/epidemiologia , Estudos Retrospectivos , Infecções dos Tecidos Moles/complicações , Infecções dos Tecidos Moles/epidemiologia
6.
J Surg Res ; 271: 82-90, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34856456

RESUMO

BACKGROUND: Most general surgery residents pursue fellowship; there is limited understanding of the impact residents and fellows have on each other's education. The goal of this exploratory survey was to identify these impacts. MATERIALS AND METHODS: Surgical residents and fellows at a single academic institution were surveyed regarding areas (OR assignments, the educational focus of the team, roles and responsibilities on the team, interpersonal communication, call, "other") hypothesized to be impacted by other learners. Impact was defined as "something that persistently affects the clinical learning environment and a trainee's education or ability to perform their job". Narrative responses were reviewed until dominant themes were identified. RESULTS: Twenty-three residents (23/45, 51%) and 12 fellows (12/21, 57%) responded. Responses were well distributed among resident year (PGY-1:17% [4/23], PGY-2, 35% [8/23], PGY-3 26% [6/23], PGY-4 9% [2/23%], PGY-5 13% [3/23]). Most residents reported OR assignment (14/23, 61%) as the area of primary impact, fellows broadly reported organizational categories (Roles and responsibilities 33%, educational focus 16%, interpersonal communication 16%). Senior residents reported missing out on operations to fellows while junior residents reported positive impacts of operating directly with fellows. Residents of all levels reported that fellows positively contributed to their education. Fellows, senior residents, and junior residents reported positive experiences when residents and fellows operated together as primary surgeon and assistant. CONCLUSIONS: Residents and fellows impact one another's education both positively and negatively. Case allocation concerns senior residents, operating together may alleviate this, providing a positive experience for all trainees. Defining a unique educational role for fellows and delineating team expectations may maximize the positive impacts in this relationship.


Assuntos
Cirurgia Geral , Internato e Residência , Competência Clínica , Educação de Pós-Graduação em Medicina , Bolsas de Estudo , Cirurgia Geral/educação , Política
7.
J Surg Res ; 268: 595-605, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34464897

RESUMO

BACKGROUND: Timely identification and management of sepsis in surgical patients is crucial, and transfer status may delay optimal treatment of these patients. The objective of this study was to compare in-house and 90-day mortality between patients primarily admitted or transferred into the surgical ICU (SICU) at a tertiary referral center. MATERIAL AND METHODS: All patients admitted to the SICU with a diagnosis of sepsis (Sepsis III) were reviewed at a single institution between 2014 to 2019 (n = 1489). Demographics, comorbidities, and sepsis presentation were compared between transferred (n = 696) and primary patients (n = 793). Primary outcomes evaluated were in-house and 90 day mortality in an unmatched and propensity score matched cohorts. A P value < 0.05 was considered statistically significant. RESULTS: Transfer patients were more likely to have obesity (60% versus 49%, P < 0.005), a higher median SOFA (6 (4-8) versus 5 (3-8), P = 0.007), and require vasopressors on admission (42% versus 35%, P = 0.004). Compared to primary patients, transfer patients exhibited higher rates of respiratory failure (76% versus 69%, P = 0.003), in-house (30% versus 17%, P < 0.005), and 90 day mortality (36% versus 24%, P < 0.005). After matching, transferred patients were associated with 75% and 83% increased odds of in-house and 90 day mortality after controlling for age, sex, race, comorbidities, BMI, and sepsis severity. CONCLUSIONS: Transfer status is associated with an over 80% increase in the odds of 90 day mortality for patients admitted to the SICU with sepsis. Aggressive patient identification and earlier transfer of those at higher risk of death may reduce this effect.


Assuntos
Unidades de Terapia Intensiva , Sepse , Cuidados Críticos , Humanos , Estudos Retrospectivos , Centros de Atenção Terciária
8.
J Surg Res ; 257: 107-117, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818779

RESUMO

BACKGROUND: Necrotizing soft-tissue infections (NSTIs) encompass a group of severe, life-threatening diseases with high morbidity and mortality. Evidence suggests advanced age is associated with worse outcomes. To date, no large data sets exist describing outcomes in older individuals, and risk factor identification is lacking. METHODS: Retrospective data were obtained from the 2015 Medicare 100% sample. Included in the analysis were those aged ≥65 y with a primary diagnosis of an NSTI (gas gangrene, necrotizing fasciitis, cutaneous gangrene, or Fournier's gangrene). Risk factors for in-hospital mortality and discharge disposition were examined. Continuous variables were assessed using central tendency, t-tests, and Wilcoxon rank-sum tests. Categorical variables were assessed using the chi-squared and Fisher's exact tests. Statistical significance was defined as P < 0.05. RESULTS: 1427 patient records were reviewed. 59% of patients were male, and the overall mean age was 75.4±8.6 y. 1385 (97.0%) patients required emergency surgery for their NSTI diagnosis. The overall mortality was 5.3%. Several underlying comorbidities were associated with higher rates of mortality including cancer (OR: 3.50, P = 0.0009), liver disease (OR: 2.97, P = 0.03), and kidney disease (OR: 2.15, P = 0.01). While associated with high in-hospital mortality, these diagnoses were not associated with a difference in the rate of discharge to home compared with skilled nursing or rehab. Overall, patients discharged to skilled nursing facilities or rehab had higher rates of underlying comorbidities than patients who were discharged home (3 or more comorbid illness 84.3% versus 68.6%, P < 0.0001); however, no individual comorbid illness was associated with discharge location. CONCLUSIONS: In our Medicare data set, we identified several medical comorbidities that are associated with increased rates of in-hospital mortality. Patients with underlying cancers had the highest odds of increased mortality. The effect on outcomes of the potentially immunosuppressive cancer treatments in these patients is unknown. These data suggest that patients with underlying illnesses, especially cancer, kidney disease, or liver disease have higher mortalities and are more likely to be discharged to skilled nursing facilities or rehab. It is unclear why these illnesses were associated with these worse outcomes while others including diabetes and heart disease were not. These data suggest that these particular comorbid illnesses may have special prognostic implications, although further analysis is necessary to identify the causative factors.


Assuntos
Infecções dos Tecidos Moles/patologia , Infecções dos Tecidos Moles/cirurgia , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Fasciite Necrosante/epidemiologia , Fasciite Necrosante/cirurgia , Feminino , Gangrena de Fournier/epidemiologia , Gangrena de Fournier/cirurgia , Gangrena Gasosa/epidemiologia , Gangrena Gasosa/cirurgia , Mortalidade Hospitalar , Hospitalização/economia , Humanos , Tempo de Internação , Masculino , Medicare/economia , Necrose , Alta do Paciente , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Infecções dos Tecidos Moles/epidemiologia , Estados Unidos/epidemiologia
9.
JPEN J Parenter Enteral Nutr ; 45(4): 800-809, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32567693

RESUMO

BACKGROUND: Initiation of parenteral nutrition (PN) after a period of starvation can be complicated by refeeding syndrome (RFS). RFS is associated with electrolyte abnormalities including hypomagnesemia, hyponatremia, and hypophosphatemia. Risk factors include recent weight loss, low body mass index, and electrolyte deficiencies; however, these associations are not strong. We hypothesized that a validated measure of nutrition risk, computed tomography (CT)-measured psoas muscle density, can be used to predict the development of hypophosphatemia associated with RFS. METHODS: A retrospective analysis of surgical patients initiated on PN with an abdominal CT scan within the past 3 months was conducted. CT-measured psoas muscle density was assessed as a predictive variable for the development of electrolyte abnormalities. Daily electrolyte and clinical outcome measures were recorded. RESULTS: One hundred nine patients were stratified based on Hounsfield unit average calculation (HUAC). The lowest 25th percentile of patients had HUAC <25. Low HUAC was associated with a significant percent decrease in phosphate levels from baseline to PN day 3 (P < .01) and significant difference in serum phosphate value on PN day 3 (P < .01). The low muscle density quartile also experienced longer days on the mechanical ventilator (P = .01) compared with patients with a higher psoas muscle density. CONCLUSION: Psoas muscle density predicted the development of hypophosphatemia in patients initiated on PN. This measurement may aid in identifying patients at highest risk of experiencing RFS. A mean psoas HU <25 may prompt additional precautions, including additional phosphate replacement and slower initiation of PN.


Assuntos
Hipofosfatemia , Sarcopenia , Humanos , Hipofosfatemia/diagnóstico por imagem , Hipofosfatemia/etiologia , Nutrição Parenteral , Músculos Psoas/diagnóstico por imagem , Músculos Psoas/patologia , Estudos Retrospectivos , Sarcopenia/patologia , Tomografia Computadorizada por Raios X
10.
J Surg Res ; 257: 278-284, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32866668

RESUMO

BACKGROUND: Emergency general surgery has higher adverse outcomes than elective surgery. Patients leaving the hospital against medical advice (AMA) have a greater risk for readmission and complications. We sought to identify clinical and demographic characteristics along with hospital factors associated with leaving AMA after EGS operations. METHODS: A retrospective review of the Nationwide Inpatient Sample was performed. All patients who underwent an EGS procedure accounting for >80% of the burden of EGS-related inpatient resources were identified. 4:1 propensity score analysis was conducted. Regression analyses determined predictive factors for leaving AMA. RESULTS: 546,856 patients were identified. 1085 (0.2%) patients who underwent EGS left AMA. They were more likely to be men (59% versus 42%), younger (median age 51 y, IQR [37.61] versus 54, IQR [38.69]), qualify for Medicaid (26% versus 13%) or be self-pay (17% versus 9%), and be within the lowest quartile median household income (40% versus 28%) (all P < 0.05). After applying 4:1 propensity score matching, individuals who were self-pay (OR 3.15, 95% CI 2.44-4.06) or insured through Medicare (OR 2.75, 95% CI 2.11-3.57) and Medicaid (OR 3.58, 95% CI 2.83-4.52) had increased odds of leaving AMA compared with privately insured patients. In addition, history of alcohol (OR 2.21, 95% CI 1.65-2.98), drug abuse (OR 4.54, 95% CI 3.23-6.38), and psychosis (OR 2.31, 95% CI 1.65-3.23) were associated with higher likelihood for leaving AMA. CONCLUSIONS: Patients undergoing EGS have a high risk of complications, and leaving AMA further increases this risk. Interventions to encourage safe discharge encompassing surgical, psychiatric, and socioeconomic factors are warranted to prevent a two-hit effect and compound postoperative risk.


Assuntos
Tratamento de Emergência/efeitos adversos , Cooperação do Paciente/estatística & dados numéricos , Alta do Paciente/normas , Complicações Pós-Operatórias/epidemiologia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Renda/estatística & dados numéricos , Masculino , Medicare/estatística & dados numéricos , Pessoa de Meia-Idade , Cooperação do Paciente/psicologia , Alta do Paciente/estatística & dados numéricos , Readmissão do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Estados Unidos/epidemiologia
11.
Biophys J ; 119(4): 780-791, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32755562

RESUMO

UNC-45B is a multidomain molecular chaperone that is essential for the proper folding and assembly of myosin into muscle thick filaments in vivo. It has previously been demonstrated that the UCS domain is responsible for the chaperone-like properties of the UNC-45B. To better understand the chaperoning function of the UCS domain of the UNC-45B chaperone, we engineered mutations designed to 1) disrupt chaperone-client interactions by removing and altering the structure of a putative client-interacting loop and 2) disrupt chaperone-client interactions by changing highly conserved residues in a putative client-binding groove. We tested the effect of these mutations by using a, to our knowledge, novel combination of complementary biophysical assays (circular dichroism, chaperone activity, and small-angle x-ray scattering) and in vivo tools (Caenorhabditis elegans sarcomere structure). Removing the putative client-binding loop altered the secondary structure of the UCS domain (by decreasing the α-helix content), leading to a significant change in its solution conformation and a reduced chaperoning function. Additionally, we found that mutating several conserved residues in the putative client-binding groove did not alter the UCS domain secondary structure or structural stability but reduced its chaperoning activity. In vivo, these groove mutations were found to significantly alter the structure and organization of C. elegans sarcomeres. Furthermore, we tested the effect of R805W, a mutation distant from the putative client-binding region, which in humans, has been known to cause congenital and infantile cataracts. Our in vivo data show that, to our surprise, the R805W mutation appeared to have the most drastic detrimental effect on the structure and organization of the worm sarcomeres, indicating a crucial role of R805 in UCS-client interactions. Hence, our experimental approach combining biophysical and biological tools facilitates the study of myosin-chaperone interactions in mechanistic detail.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Humanos , Chaperonas Moleculares/genética , Miosinas/genética , Sarcômeros
12.
Am J Surg ; 220(4): 893-898, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32248947

RESUMO

INTRODUCTION: The goal of this study was to explore the resident construct for their perceived successful method of actions that lead to OR autonomy during residency and the strategies they employed. METHODS: We conducted focus group interviews with residents from the General Surgery (GS) and Obstetrics & Gynecology (OBGYN) departments at a single academic institution across all clinical postgraduate years (PGY) using convenience sampling. Audio recordings of each interview were transcribed, analyzed and emergent themes were identified using a framework method. RESULTS: A total of 38 residents participated. A 3-stage resident method to gain operative autonomy emerged. This progresses from building rapport, developing mutual entrustment, and finally to obtaining autonomy. We identified 4 common strategies used by residents to construct this method: smart communication, attention to attending preferences, helpful allies and visible attributes. CONCLUSION: Our findings provide insight into resident strategies to achieve progressive autonomy in the OR helping programs improve resident's learning efficiency.


Assuntos
Competência Clínica , Cirurgia Geral/educação , Ginecologia/educação , Internato e Residência , Obstetrícia/educação , Feminino , Humanos , Masculino , Salas Cirúrgicas
14.
Br J Nutr ; 119(5): 517-526, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29508695

RESUMO

This study was a randomised, double-blind, placebo-controlled cross-over trial examining the effects of ß-hydroxy ß-methylbutyrate free acid (HMB-FA) supplementation on muscle protein breakdown, cortisol, testosterone and resting energy expenditure (REE) during acute fasting. Conditions consisted of supplementation with 3 g/d HMB-FA or placebo during a 3-d meat-free diet followed by a 24-h fast. Urine was collected before and during the 24-h fast for analysis of 3-methylhistidine:creatinine ratio (3MH:CR). Salivary cortisol, testosterone, their ratio (T:C), and the cortisol awakening response were assessed. ANOVA was used to analyse all dependent variables, and linear mixed models were used to confirm the absence of carryover effects. Eleven participants (six females, five males) completed the study. Urinary HMB concentrations confirmed compliance with supplementation. 3MH:CR was unaffected by fasting and supplementation, but the cortisol awakening response differed between conditions. In both conditions, cortisol increased from awakening to 30 min post-awakening (P=0·01). Cortisol was reduced from 30 to 45 min post-awakening with HMB-FA (-32 %, d=-1·0, P=0·04), but not placebo (PL) (-6 %, d=-0·2, P=0·14). In males, T:C increased from 0 to 24 h of fasting with HMB-FA (+162 %, d=3·0, P=0·001), but not placebo (+13 %, d=0·4, P=0·60), due to reductions in cortisol. REE was higher at 24 h of fasting than 16 h of fasting independent of supplementation (+4·0 %, d=0·3, P=0·04). In conclusion, HMB-FA may affect cortisol responses, but not myofibrillar proteolysis, during acute 24-h fasting.


Assuntos
Suplementos Nutricionais , Jejum/fisiologia , Hidrocortisona/metabolismo , Músculo Esquelético/efeitos dos fármacos , Miofibrilas/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Valeratos/farmacologia , Adulto , Metabolismo Basal , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Músculo Esquelético/metabolismo , Miofibrilas/metabolismo , Descanso , Testosterona/metabolismo , Adulto Jovem
15.
Zebrafish ; 14(4): 387-389, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28318435

RESUMO

Antibodies raised against mammalian proteins may exhibit cross-reactivity with zebrafish proteins, making these antibodies useful for fish studies. However, zebrafish may express multiple paralogues of similar sequence and size, making them difficult to distinguish by traditional Western blot analysis. To identify the zebrafish proteins that are recognized by an antimammalian antibody, we developed a system to screen putative epitopes by cloning the sequences between the yeast SUMO protein and a C-terminal 6xHis tag. The recombinant fusion protein was expressed in Escherichia coli and analyzed by Western blot to conclusively identify epitopes that exhibit cross-reactivity with the antibodies of interest. This approach can be used to determine the species cross-reactivity and epitope specificity of a wide variety of peptide antigen-derived antibodies.


Assuntos
Anticorpos/imunologia , Mapeamento de Epitopos/métodos , Proteínas de Peixe-Zebra/imunologia , Peixe-Zebra/imunologia , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Western Blotting , Histidina/química , Histidina/metabolismo , Humanos , Receptor MT1 de Melatonina/imunologia , Receptor MT2 de Melatonina/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo
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