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1.
J Med Internet Res ; 22(5): e16708, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32406851

RESUMO

BACKGROUND: Physician rating websites are commonly used by the public, yet the relationship between web-based physician ratings and health care quality is not well understood. OBJECTIVE: The objective of our study was to use physician disciplinary convictions as an extreme marker for poor physician quality and to investigate whether disciplined physicians have lower ratings than nondisciplined matched controls. METHODS: This was a retrospective national observational study of all disciplined physicians in Canada (751 physicians, 2000 to 2013). We searched ratings (2005-2015) from the country's leading online physician rating website for this group, and for 751 matched controls according to gender, specialty, practice years, and location. We compared overall ratings (out of a score of 5) as well as mean ratings by the type of misconduct. We also compared ratings for each type of misconduct and punishment. RESULTS: There were 62.7% (471/751) of convicted and disciplined physicians (cases) with web-based ratings and 64.6% (485/751) of nondisciplined physicians (controls) with ratings. Of 312 matched case-control pairs, disciplined physicians were rated lower than controls overall (3.62 vs 4.00; P<.001). Disciplined physicians had lower ratings for all types of misconduct and punishment-except for physicians disciplined for sexual offenses (n=90 pairs; 3.83 vs 3.86; P=.81). Sexual misconduct was the only category in which mean ratings for physicians were higher than those for other disciplined physicians (3.63 vs 3.35; P=.003). CONCLUSIONS: Physicians convicted for disciplinary misconduct generally had lower web-based ratings. Physicians convicted of sexual misconduct did not have lower ratings and were rated higher than other disciplined physicians. These findings may have future implications for the identification of physicians providing poor-quality care.


Assuntos
Médicos/legislação & jurisprudência , Má Conduta Profissional/estatística & dados numéricos , Estudos de Casos e Controles , Feminino , Humanos , Internet , Masculino , Satisfação do Paciente , Estudos Retrospectivos
3.
Transfusion ; 59(6): 2141-2149, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30946497

RESUMO

BACKGROUND: The optimal method of providing transfusion medicine (TM) education has not been determined. Transfusion Camp was established in 2012 at the University of Toronto as a centrally delivered TM education program for postgraduate trainees. The impact of Transfusion Camp on knowledge, attitudes, and self-reported behavior was evaluated. METHODS: Didactic lectures (delivered locally, by webinar, or recorded) and locally facilitated team-based learning seminars were delivered over 5 days during the academic year to 8 sites: 7 in Canada and 1 in the United Kingdom. Knowledge assessment using a validated 20-question multiple-choice exam was conducted before and after Transfusion Camp. Attitudes and self-reported behavior were collected through a survey. RESULTS: Over 2 academic years (July 2016 to June 2018), 390 trainees from 16 different specialties (predominantly anesthesia, 41%; hematology, 14%; and critical care, 7%) attended at least 1 day of Transfusion Camp. The mean pretest score was 10.3 of 20 (±2.9; n = 286) compared with posttest score of 13.0 (±2.8; n = 194; p < 0.0001). Lower pretest score and greater attendance (4-5 days compared with 1-3 days) were associated with larger improvement in posttest score; delivery format, specialty, and postgraduate year were not. Trainees reported an improvement in self-rated abilities to manage TM scenarios; 95% rated TM knowledge as very or extremely important in providing patient care; and 81% indicated that they had applied learning from Transfusion Camp into clinical practice. CONCLUSIONS: Transfusion Camp increased TM knowledge, fostered a positive attitude toward TM, and enabled a self-reported positive impact on transfusion practice in postgraduate trainees. It is a novel and scalable approach to delivering TM education.


Assuntos
Transfusão de Sangue , Currículo , Hematologia/educação , Internato e Residência/métodos , Medicina Transfusional/educação , Atitude , Transfusão de Sangue/métodos , Transfusão de Sangue/normas , Canadá , Currículo/normas , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Internato e Residência/organização & administração , Medicina , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Autorrelato , Estudantes de Medicina/psicologia
4.
J Pharmacol Exp Ther ; 365(3): 536-543, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29581154

RESUMO

Previously, we demonstrated that nitric oxide (NO) synthase (NOS) is uncoupled in a wide range of solid tumors and that restoring NOS coupling with the tetrahydrobiopterin precursor sepiapterin (SP) inhibits tumor progression. Endothelial dysfunction characterizes the poorly functional vasculature of solid tumors, and since NO is critical for regulation of endothelial function we asked whether SP, by recoupling NOS, improves tumor vasculature structure and function-enhancing chemotherapeutic delivery and response to radiotherapy. MMTV-neu mice with spontaneous breast tumors were treated with SP by oral gavage and evaluated by multispectral optoacoustic tomographic analysis of tumor HbO2 and by tissue staining for markers of hypoxia, blood perfusion, and markers of endothelial and smooth muscle proteins. Recoupling tumor NOS activity results in vascular normalization observed as reduced tumor hypoxia, improved tumor percentage of HbO2 and perfusion, as well as increased pericyte coverage of tumor blood vessels. The normalized vasculature and improved tumor oxygenation led to a greater than 2-fold increase in radiation-induced apoptosis compared with radiation or SP alone. High-performance liquid chromatography analysis of tumor doxorubicin levels showed a greater than 50% increase in doxorubicin uptake and a synergistic effect on tumor cell apoptosis. This study highlights for the first time the importance of NOS uncoupling and endothelial dysfunction in the development of tumor vasculature and presents a new approach for improving the tumoricidal efficacies of chemotherapy and radiotherapy.


Assuntos
Antineoplásicos/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Pterinas/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Animais , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/efeitos da radiação , Circulação Sanguínea/efeitos dos fármacos , Circulação Sanguínea/efeitos da radiação , Vasos Sanguíneos/fisiopatologia , Vasos Sanguíneos/efeitos da radiação , Linhagem Celular Tumoral , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Sinergismo Farmacológico , Humanos , Camundongos , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/metabolismo , Oxigênio/metabolismo , Hipóxia Tumoral/efeitos dos fármacos , Hipóxia Tumoral/efeitos da radiação
5.
Jt Comm J Qual Patient Saf ; 44(6): 361-365, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29793887

RESUMO

BACKGROUND: Physician misconduct adversely affects patient safety and is therefore of societal importance. Little work has specifically examined re-disciplined physicians. A study was conducted to compare the characteristics of re-disciplined to first-time disciplined physicians. METHODS: A retrospective review of Canadian physicians disciplined by medical boards between 2000 and 2015 was conducted. Physicians were divided into those disciplined once and those disciplined more than once. Differences in demographics, transgressions, and penalties were evaluated. RESULTS: There were 938 disciplinary events for 810 disciplined physicians with 1 in 8 (n = 101, 12.5%) being re-disciplined. Re-disciplined physicians had up to six disciplinary events in the study period and 4 (4.0%) had events in more than one jurisdiction. Among those re-disciplined, 94 (93.1%) were male, 34 (33.7%) were international medical graduates, and 88 (87.1%) practiced family medicine (n = 59, 58.4%), psychiatry (n = 11, 10.9%), surgery (n = 9, 8.9%), or obstetrics/gynecology (n = 9, 8.9%). The proportion of obstetrician/gynecologists was higher among re-disciplined physicians (8.9% vs. 4.2%, p = 0.048). Re-disciplined physicians had more mental illness (1.7% vs. 0.1%, p = 0.01), unlicensed activity (19.2% vs. 7.2%, p <0.01), and less sexual misconduct (20.1% vs. 27.9%, p = 0.02). License suspension occurred more frequently among those re-disciplined (56.8% vs. 48.0%, p = 0.02) as did license restriction (38.4% vs. 26.7%, p <0.01). License revocation was not different between cohorts (10.9% vs. 13.5%, p = 0.36). CONCLUSION: Re-discipline is not uncommon and underscores the need for better identification of at-risk individuals and optimization of remediation and penalties. The distribution of transgression argues for a national disciplinary database that could improve communication between jurisdictional medical boards.


Assuntos
Médicos/estatística & dados numéricos , Má Conduta Profissional/estatística & dados numéricos , Conselhos de Especialidade Profissional/estatística & dados numéricos , Fatores Etários , Canadá , Médicos Graduados Estrangeiros/estatística & dados numéricos , Humanos , Licenciamento em Medicina/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Estudos Retrospectivos , Fatores Sexuais , Fatores Socioeconômicos , Especialização/estatística & dados numéricos , Conselhos de Especialidade Profissional/normas
6.
Crit Care ; 20(1): 107, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-27095272

RESUMO

Hypothermia is present in up to two-thirds of patients with severe injury, although it is often disregarded during the initial resuscitation. Studies have revealed that hypothermia is associated with mortality in a large percentage of trauma cases when the patient's temperature is below 32 °C. Risk factors include the severity of injury, wet clothing, low transport unit temperature, use of anesthesia, and prolonged surgery. Fortunately, associated coagulation disorders have been shown to completely resolve with aggressive warming. Selected passive and active warming techniques can be applied in damage control resuscitation. While treatment guidelines exist for acidosis and bleeding, there is no evidence-based approach to managing hypothermia in trauma patients. We synthesized a goal-directed algorithm for warming the severely injured patient that can be directly incorporated into current Advanced Trauma Life Support guidelines. This involves the early use of warming blankets and removal of wet clothing in the prehospital phase followed by aggressive rewarming on arrival at the hospital if the patient's injuries require damage control therapy. Future research in hypothermia management should concentrate on applying this treatment algorithm and should evaluate its influence on patient outcomes. This treatment strategy may help to reduce blood loss and improve morbidity and mortality in this population of patients.


Assuntos
Hipotermia/etiologia , Reação Transfusional , Ferimentos e Lesões/complicações , Transfusão de Sangue/mortalidade , Gerenciamento Clínico , Humanos , Hipotermia/mortalidade , Ressuscitação/efeitos adversos , Reaquecimento/métodos , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/fisiopatologia
7.
Can J Anaesth ; 63(1): 61-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26507535

RESUMO

PURPOSE: The objectives for preparing this article were to review the historical context and epidemiology surrounding the North American prescription opioid crisis, to summarize the evidence regarding the benefits and harms of long-term opioid therapy for non-cancer pain, and to outline ways in which anesthesiologists may help ameliorate the problem. SOURCE: We searched PubMed, Google Scholar, and EMBASE™ for relevant articles using various search terms, including pain, opioid epidemic, history of opioid use, perioperative care, and addiction. Related citations were further explored and searched depending on the specific subtopic of interest. PRINCIPAL FINDINGS: In the 1980s and early 1990s, opioids were infrequently used for the treatment of chronic pain. Thereafter, however, physicians were gradually inculcated with the message that long-term opioid therapy was a safe and effective treatment option for patients with chronic non-cancer pain. Pharmaceutical companies supported this growing movement and employed aggressive and sometimes misleading marketing strategies for new opioid formulations. As a result, the practice of prescribing opioids flourished in the late 1990s. The surge in prescribing opioids was accompanied by a marked increase in opioid-related morbidity and mortality. This change in practice transpired despite the absence of randomized trials showing clinically significant benefit from the long-term use of opioids. Subsequently, however, a large and growing body of evidence has emerged quantifying the harms associated with long-term opioid therapy. Anesthesiologists widely prescribe opioids for acute and chronic pain; yet, as a group, they may be largely unaware of the current state of this growing epidemic and what role they can play to rectify this problem. CONCLUSION: Anesthesiologists are well positioned to take a leadership role in the management of postoperative discharge opioid therapy in an effort to curb the overutilization of opioids. Furthermore, anesthesiologists who regularly prescribe opioids for chronic pain patients should appreciate the limited evidence base for this practice and communicate the risks of opioid therapy to their patients.


Assuntos
Analgésicos Opioides/uso terapêutico , Anestesiologia , Analgésicos Opioides/efeitos adversos , Dor Crônica/tratamento farmacológico , Prescrições de Medicamentos/estatística & dados numéricos , Humanos
8.
Mol Med ; 21: 210-8, 2015 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-25822795

RESUMO

Thoracic X-ray therapy (XRT), used in cancer treatment, is associated with increased risk of heart failure. XRT-mediated injury to the heart induces an inflammatory response leading to cardiomyopathy. The aim of this study was to determine the role of interleukin (IL)-1 in response to XRT injury to the heart and on the cardiomyopathy development in the mouse. Female mice with genetic deletion of the IL-1 receptor type I (IL-1R1 knockout mice [IL-1R1 KO]) and treatment with recombinant human IL-1 receptor antagonist anakinra, 10 mg/kg twice daily for 7 d, were used as independent approaches to determine the role of IL-1. Wild-type (wt) or IL-1R1 KO mice were treated with a single session of XRT (20 or 14 gray [Gy]). Echocardiography (before and after isoproterenol challenge) and left ventricular (LV) catheterization were performed to evaluate changes in LV dimensions and function. Masson's trichrome was used to assess myocardial fibrosis and pericardial thickening. After 20 Gy, the contractile reserve was impaired in wt mice at d 3, and the LV ejection fraction (EF) was reduced after 4 months when compared with sham-XRT. IL-1R1 KO mice had preserved contractile reserve at 3 d and 4 months and LVEF at 4 months after XRT. Anakinra treatment for 1 d before and 7 d after XRT prevented the impairment in contractile reserve. A significant increase in LV end-diastolic pressure, associated with increased myocardial interstitial fibrosis and pericardial thickening, was observed in wt mice, as well as in IL-1R1 KO-or anakinra-treated mice. In conclusion, induction of IL-1 by XRT mediates the development of some, such as the contractile impairment, but not all aspects of the XRT-induced cardiomyopathy, such as myocardial fibrosis or pericardial thickening.


Assuntos
Cardiomiopatias/etiologia , Cardiomiopatias/metabolismo , Interleucina-1/metabolismo , Lesões Experimentais por Radiação , Animais , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Modelos Animais de Doenças , Relação Dose-Resposta à Radiação , Feminino , Fibrose , Hemodinâmica , Camundongos , Camundongos Knockout , Receptores Tipo I de Interleucina-1/deficiência , Transdução de Sinais , Disfunção Ventricular Esquerda
9.
Transfus Apher Sci ; 50(3): 392-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24797240

RESUMO

PURPOSE: Transfusion-related acute lung injury (TRALI) is a devastating transfusion-associated adverse event. There is a paucity of data on the incidence and characteristics of TRALI cases that occur perioperatively. We classified suspected perioperative TRALI cases reported to Canadian Blood Services between 2001 and 2012, and compared them to non-perioperative cases to elucidate factors that may be associated with an increased risk of developing TRALI in the perioperative setting. METHODS: All suspected TRALI cases reported to Canadian Blood Services (CBS) since 2001 were reviewed by two experts or, from 2006 to 2012, the CBS TRALI Medical Review Group (TMRG). These cases were classified based on the Canadian Consensus Conference (CCC) definitions and detailed in a database. Two additional reviewers further categorized them as occurring within 72 h from the onset of surgery (perioperative) or not in that period (non-perioperative). Various demographic and characteristic variables of each case were collected and compared between groups. RESULTS: Between 2001 and 2012, a total of 469 suspected TRALI cases were reported to Canadian Blood Services; 303 were determined to be within the TRALI diagnosis spectrum. Of those, 112 (38%) were identified as occurring during the perioperative period. Patients who underwent cardiac surgery requiring cardiopulmonary bypass (25.0%), general surgery (18.0%) and orthopedics patients (12.5%) represented the three largest surgical groups. Perioperative TRALI cases comprised more men (53.6% vs. 41.4%, p=0.04) than non-perioperative patients. Perioperative TRALI patients more often required supplemental O2 (14.3% vs. 3.1%, p=0.0003), mechanical ventilation (18.8% vs. 3.1%), or were in the ICU (14.3% vs. 3.7%, p=0.0043) prior to the onset of TRALI compared to non-perioperative TRALI patients. The surgical patients were transfused on average more components than non-perioperative patients (6.0 [SD=8.3] vs. 3.6 [5.2] products per patient, p=0.0002). Perioperative TRALI patients were transfused more plasma (152 vs. 105, p=0.013) and cryoprecipitate (51 vs. 23, p<0.01) than non-perioperative TRALI patients. There was no difference between donor antibody test results between the groups. CONCLUSION: CBS data has provided insight into the nature of TRALI cases that occur perioperatively; this group represents a large proportion of TRALI cases.


Assuntos
Lesão Pulmonar Aguda , Bases de Dados Factuais , Assistência Perioperatória , Reação Transfusional , Lesão Pulmonar Aguda/epidemiologia , Lesão Pulmonar Aguda/etiologia , Adulto , Fatores Etários , Idoso , Canadá/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores Sexuais
10.
Can J Anaesth ; 61(5): 441-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24585233

RESUMO

PURPOSE: When exposed in the perioperative period to blood components containing immunoglobulin (Ig)A IgA-sensitized IgA-deficient patients are at an increased risk of transfusion-associated anaphylaxis. We present the case of an IgA-deficient patient whose candidacy for double-lung transplantation was under review in the preoperative period. CLINICAL FEATURES: A 49-yr-old patient with end-stage chronic obstructive lung disease secondary to deficiencies in IgA and IgG subclasses was being assessed for double-lung transplantation. Early recognition of the ramifications of perioperative transfusion prompted consultation with the transfusion medicine service. This in turn facilitated specialized laboratory testing and the coordinated provision of appropriate blood products for the unpredictable date of transplantation. The theoretical systemic risks of a non-IgA-deficient graft on the sensitized IgA-deficient host were considered. To affirm the patient's candidacy for transplantation, he was ultimately challenged preoperatively with IgA-containing products in a controlled intensive-care setting. CONCLUSION: Through a multidisciplinary approach [corrected], a successful transplantation outcome was achieved in an IgA-deficient patient undergoing major surgery. Strategies to mitigate risk include the procurement and transfusion of IgA-deficient components, which may be challenging or untenable in emergent perioperative settings.


Assuntos
Deficiência de IgA/complicações , Transplante de Pulmão/métodos , Assistência Perioperatória/métodos , Doença Pulmonar Obstrutiva Crônica/cirurgia , Humanos , Deficiência de IgG/complicações , Imunoglobulina A/administração & dosagem , Comunicação Interdisciplinar , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/etiologia , Resultado do Tratamento
11.
J Pharmacol Exp Ther ; 347(1): 117-25, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23912334

RESUMO

The effects of modulating tetrahydrobiopterin (BH4) levels with a metabolic precursor, sepiapterin (SP), on dextran sodium sulfate (DSS)-induced colitis and azoxymethane (AOM)-induced colorectal cancer were studied. SP in the drinking water blocks DSS-induced colitis measured as decreased disease activity index (DAI), morphologic criteria, and recovery of Ca(2+)-induced contractility responses lost as a consequence of DSS treatment. SP reduces inflammatory responses measured as the decreased number of infiltrating inflammatory macrophages and neutrophils and decreased expression of proinflammatory cytokines interleukin 1ß (IL-1ß), IL-6, and IL-17A. High-performance liquid chromatography analyses of colonic BH4 and its oxidized derivative 7,8-dihydrobiopterin (BH2) are inconclusive although there was a trend for lower BH4:BH2 with DSS treatment that was reversed with SP. Reduction of colonic cGMP levels by DSS was reversed with SP by a mechanism sensitive to 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a specific inhibitor of the NO-sensitive soluble guanylate cyclase (sGC). ODQ abrogates the protective effects of SP on colitis. This plus the finding that SP reduces DSS-enhanced protein Tyr nitration are consistent with DSS-induced uncoupling of NOS. The results agree with previous studies that demonstrated inactivation of sGC in DSS-treated animals as being important in recruitment of inflammatory cells and in altered cholinergic signaling and colon motility. SP also reduces the number of colon tumors in AOM/DSS-treated mice from 7 to 1 per unit colon length. Thus, pharmacologic modulation of BH4 with currently available drugs may provide a mechanism for alleviating some forms of colitis and potentially minimizing the potential for colorectal cancer in patients with colitis.


Assuntos
Azoximetano/toxicidade , Colite/induzido quimicamente , Colite/prevenção & controle , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/prevenção & controle , Pterinas/uso terapêutico , Animais , Colite/patologia , Neoplasias do Colo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos
12.
Can J Anaesth ; 60(10): 1013-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23897490

RESUMO

PURPOSE: Previous studies discussing the risk of medical misconduct amongst anesthesiologists differ in their conclusions. In Canada, there is a paucity of data regarding demographic information, disciplinary findings, and penalties received by anesthesiologists. The aim of this study was to identify potential characteristics for discipline within the specialty of anesthesiology by ascertaining disciplinary findings and types of penalties received by anesthesiologists and comparing these with cases of disciplinary action against other Canadian physicians. METHODS: Using a retrospective cohort design, we constructed a database of all Canadian physicians disciplined by their respective provincial and territorial regulatory colleges between 2000-2011. We collected and compared physician demographic information, types of disciplinary findings, and penalties received by anesthesiologists and other physicians during that time period. RESULTS: Between 2000-2011, various physicians were disciplined 721 times in Canada. Nine anesthesiologists were found guilty of 11 (1.5%) disciplinary findings. One anesthesiologist was disciplined three separate times. All anesthesiologists subject to discipline were males, ten (90.9%) were independent practitioners, and almost two-thirds (63.6%) were international medical graduates. The most common types of disciplinary findings were related to standard of care issues, inappropriate prescribing, and fraudulent behaviour. Anesthesiologists appeared less likely than other physicians to be disciplined for sexual misconduct and unprofessional behaviour. CONCLUSION: Anesthesiologists in Canada have been subject to low rates of disciplinary action. Specifically, there have been low rates of sexual misconduct and unprofessional behaviour. Interventions to reduce disciplinary findings in anesthesiology could be directed toward bolstering education relating to standard of care issues, prescribing practices, and fraudulent behaviour.


Assuntos
Anestesiologia/estatística & dados numéricos , Médicos/estatística & dados numéricos , Autonomia Profissional , Má Conduta Profissional/estatística & dados numéricos , Anestesiologia/normas , Canadá , Estudos de Coortes , Bases de Dados Factuais , Feminino , Humanos , Masculino , Médicos/normas , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricos , Estudos Retrospectivos , Padrão de Cuidado
14.
Front Oncol ; 13: 1165326, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36998441

RESUMO

Increased levels of reactive oxygen/nitrogen species are one hallmark of chronic inflammation contributing to the activation of pro-inflammatory/proliferative pathways. In the cancers analyzed, the tetrahydrobiopterin:dihydrobiopterin ratio is lower than that of the corresponding normal tissue, leading to an uncoupled nitric oxide synthase activity and increased generation of reactive oxygen/nitrogen species. Previously, we demonstrated that prophylactic treatment with sepiapterin, a salvage pathway precursor of tetrahydrobiopterin, prevents dextran sodium sulfate-induced colitis in mice and associated azoxymethane-induced colorectal cancer. Herein, we report that increasing the tetrahydrobiopterin:dihydrobiopterin ratio and recoupling nitric oxide synthase with sepiapterin in the colon cancer cell lines, HCT116 and HT29, inhibit their proliferation and enhance cell death, in part, by Akt/GSK-3ß-mediated downregulation of ß-catenin. Therapeutic oral gavage with sepiapterin of mice bearing azoxymethane/dextran sodium sulfate-induced colorectal cancer decreased metabolic uptake of [18F]-fluorodeoxyglucose and enhanced apoptosis nine-fold in these tumors. Immunohistochemical analysis of both mouse and human tissues indicated downregulated expression of key enzymes in tetrahydrobiopterin biosynthesis in the colorectal cancer tumors. Human stage 1 colon tumors exhibited a significant decrease in the expression of quinoid dihydropteridine reductase, a key enzyme involved in recycling tetrahydrobiopterin suggesting a potential mechanism for the reduced tetrahydrobiopterin:dihydrobiopterin ratio in these tumors. In summary, sepiapterin treatment of colorectal cancer cells increases the tetrahydrobiopterin:dihydrobiopterin ratio, recouples nitric oxide synthase, and reduces tumor growth. We conclude that nitric oxide synthase coupling may provide a useful therapeutic target for treating patients with colorectal cancer.

15.
New Solut ; 33(2-3): 119-129, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37649363

RESUMO

Silicosis in workers exposed to respirable crystalline silica while fabricating engineered stone products is an emerging respiratory health issue. We describe silicosis in engineered stone workers in California and examine clinical features by the source of identification. Cases were identified passively using hospital-based patient discharge data or actively through outreach and medical testing following enforcement investigation. Outcomes were examined based on the source of case identification. We identified 18 cases diagnosed between 2006 and 2020. Cases identified passively compared to other identification methods were associated with lower percent predicted forced vital capacity (FVC) (P ≤ .01), forced expiratory volume in 1 s (FEV1) (P ≤ .01), and diffusing capacity of the lungs for carbon monoxide (DLCO) (P < .01) at the time of diagnosis and were more likely to be identified following death or lung transplant (P = .01). Our experience demonstrates delays in diagnosis and case identification when relying on passive surveillance methods. Enhanced public health surveillance systems can improve the early detection of occupational lung disease and inform future prevention policies.


Assuntos
Doenças Profissionais , Exposição Ocupacional , Silicose , Humanos , Conduta Expectante , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , Silicose/epidemiologia , Silicose/diagnóstico , Dióxido de Silício/análise
16.
Sci Rep ; 13(1): 4512, 2023 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-36934142

RESUMO

Postpartum haemorrhage (PPH) is a leading cause of maternal morbidity and mortality. While tranexamic acid (TXA) reduces bleeding and transfusion requirements in established PPH, we sought to determine the feasibility of conducting a fully powered trial assessing the effect of prophylactic tranexamic acid, prior to PPH onset, in a Canadian Obstetric setting. With institutional and Health Canada approval, consenting, eligible parturients (singleton, > 32 weeks gestation, vaginal or caesarian delivery) were randomly assigned to receive TXA (1 g intravenously) or placebo (0.9% saline) prior to delivery. Participants, investigators, data collectors/adjudicators, and analysis was blinded. The primary outcome was administration of study intervention to > 85% of randomized individuals. Secondary outcomes included recruitment rate (feasibility) and safety outcomes. Over 8 months, 611 were approached, 35 consented, and 27 randomized (14 TXA, 13 placebo). 89% of randomized participants received the assigned intervention. Recruitment fell below feasibility (23% target). No serious adverse outcomes occurred. Our pilot trial in a Canadian Obstetric setting was unable to demonstrate feasibility to conduct a large, multicentre trial to examine prophylactic use of tranexamic for PPH secondary to the complex regulatory requirements associated with a trial for an off-label, but commonly utilized intervention. These challenges should inform stakeholders on the resources and challenges of conducting future trials using off-label interventions.Trial registration: www.clinicaltrials.gov , NCT03069859 (03/03/2017).


Assuntos
Antifibrinolíticos , Hemorragia Pós-Parto , Ácido Tranexâmico , Gravidez , Feminino , Humanos , Ácido Tranexâmico/uso terapêutico , Hemorragia Pós-Parto/tratamento farmacológico , Hemorragia Pós-Parto/prevenção & controle , Projetos Piloto , Antifibrinolíticos/uso terapêutico , Canadá
17.
Clin Transl Gastroenterol ; 13(5): e00477, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35347095

RESUMO

INTRODUCTION: Despite studies showing improved safety, efficacy, and cost-effectiveness of endoscopic resection for nonmalignant colorectal polyps, colectomy rates for nonmalignant colorectal polyps have been increasing in the United States and Europe. Given this alarming trend, we aimed to investigate whether colectomy rates for nonmalignant colorectal polyps are increasing or declining in a large, integrated, community-based healthcare system with access to advanced endoscopic resection procedures. METHODS: We identified all individuals aged 50-85 years who underwent a colonoscopy between 2008 and 2018 and were diagnosed with a nonmalignant colorectal polyp(s) at the Kaiser Permanente Northern California integrated healthcare system. Among these individuals, we identified those who underwent a colectomy for nonmalignant colorectal polyps within 12 months after the colonoscopy. We calculated annual colectomy rates for nonmalignant colorectal polyps and stratified rates by age, sex, and race and ethnicity. Changes in rates over time were tested by the Cochran-Armitage test for a linear trend. RESULTS: Among 229,730 patients who were diagnosed with nonmalignant colorectal polyps between 2008 and 2018, 1,611 patients underwent a colectomy. Colectomy rates for nonmalignant colorectal polyps decreased significantly from 125 per 10,000 patients with nonmalignant polyps in 2008 to 12 per 10,000 patients with nonmalignant polyps in 2018 (P < 0.001 for trend). When stratified by age, sex, and race and ethnicity, colectomy rates for nonmalignant colorectal polyps also significantly declined from 2008 to 2018. DISCUSSION: In a large, ethnically diverse, community-based population in the United States, we found that colectomy rates for nonmalignant colorectal polyps declined significantly over the past decade likely because of the establishment of advanced endoscopy centers, improved care coordination, and an organized colorectal cancer screening program.


Assuntos
Pólipos do Colo , Neoplasias Colorretais , Colectomia/efeitos adversos , Colectomia/métodos , Pólipos do Colo/diagnóstico , Pólipos do Colo/epidemiologia , Pólipos do Colo/cirurgia , Colonoscopia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/cirurgia , Endoscopia Gastrointestinal , Humanos , Estados Unidos/epidemiologia
18.
CJEM ; 22(S2): S12-S20, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33084553

RESUMO

OBJECTIVES: In traumatically injured patients, excessive blood loss necessitating the transfusion of red blood cell (RBC) units is common. Indicators of early RBC transfusion in the pre-hospital setting are needed. This study aims to evaluate the association between hypothermia (<36°C) and transfusion risk within the first 24 hours after arrival to hospital for a traumatic injury. METHODS: We completed an audit of all traumatically injured patients who had emergent surgery at a single tertiary care center between 2010 and 2014. Using multivariable logistic regression analysis, we evaluated the association between pre-hospital hypothermia and transfusion of ≥1 unit of RBC within 24 hours of arrival to the trauma bay. RESULTS: Of the 703 patients included to evaluate the association between hypothermia and RBC transfusion, 203 patients (29%) required a transfusion within 24 hours. After controlling for important confounding variables, including age, sex, coagulopathy (platelets and INR), hemoglobin, and vital signs (blood pressure and heart rate), hypothermia was associated with a 68% increased odds of transfusion in multivariable analysis (OR: 1.68; 95% CI: 1.11-2.56). CONCLUSIONS: Hypothermia is strongly associated with RBC transfusion in a cohort of trauma patients requiring emergent surgery. This finding highlights the importance of early measures of temperature after traumatic injury and the need for intervention trials to determine if strategies to mitigate the risk of hypothermia will decrease the risk of transfusion and other morbidities.


Assuntos
Hipotermia , Ferimentos e Lesões , Transtornos da Coagulação Sanguínea , Transfusão de Sangue , Hospitais , Humanos , Hipotermia/etiologia , Estudos Retrospectivos , Reação Transfusional
20.
Redox Biol ; 24: 101169, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30889466

RESUMO

Recently, clinical development of PARP inhibitors (PARPi) expanded from using them as a single agent to combining them with DNA-damaging therapy to derive additional therapeutic benefit from stimulated DNA damage. Furthermore, inhibiting PARP in cancers with BRCA1/2 mutations has been shown to be an effective synthetic lethality approach either as a single agent or in combination with the different DNA damaging agents: chemotherapy or ionizing radiation (IR). However, inherited BRCA1/2 mutations account only for 5-10% of breast cancers, 10-15% of ovarian cancers, and lesser for the other cancers. Hence, for most of the cancer patients with BRCA1/2-proficient tumors, sensitization to DNA-damaging agents with PARPi is significantly less effective. We recently demonstrated that moderate, non-toxic concentrations of NO-donors inhibited BRCA1 expression, with subsequent inhibition of error-free HRR and increase of error-prone non-homologous end joining (NHEJ). We also demonstrated that the effect of NO-dependent block of BRCA1 expression can only be achieved in the presence of oxidative stress, a condition that characterizes the tumor microenvironment and is also a potential effect of IR. Hence, NO-donors in combination with PARPi, with effects limited by tumor microenvironment and irradiated area, suggest a precise tumor-targeted approach for radio-sensitization of BRCA1/2-proficient tumors. The combination with NO-donors allows PARPi to be successfully applied to a wider variety of tumors. The present work demonstrates a new drug combination (NO-donors and PARP-inhibitors) which demonstrated a high potency in sensitization of wide variety of tumors to ionizing radiation treatment.


Assuntos
Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/química , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Benzimidazóis/química , Benzimidazóis/farmacologia , Linhagem Celular Tumoral , Dano ao DNA , Reparo do DNA , Ácido Edético/química , Humanos , Tolerância a Radiação/efeitos dos fármacos , Tolerância a Radiação/efeitos da radiação , Radiação Ionizante , Proteína p130 Retinoblastoma-Like/metabolismo , Transdução de Sinais , Mutações Sintéticas Letais/efeitos dos fármacos , Mutações Sintéticas Letais/genética
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