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1.
J Intern Med ; 284(4): 346-357, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29923256

RESUMO

Statin drugs have been used for more than two decades to treat hypercholesterolemia and as cardio-preventive drugs, resulting in a marked decrease in cardiovascular morbidity and mortality worldwide. Statins halt hepatic cholesterol biosynthesis by inhibiting the rate-limiting enzyme in the mevalonate pathway, hydroxymethylglutaryl-coenzyme A reductase (HMGCR). The mevalonate pathway regulates a host of biochemical processes in addition to cholesterol production. Attenuation of these pathways is likely responsible for the myriad benefits of statin therapy beyond cholesterol reduction - the so-called pleiotropic effects of statins. Chief amongst these purported effects is anti-cancer activity. A considerable body of preclinical, epidemiologic and clinical evidence shows that statins impair proliferation of breast cancer cells and reduce the risk of breast cancer recurrence. Potential mechanisms for this effect have been explored in laboratory models, but remain poorly understood and require further investigation. The number of clinical trials assessing the putative clinical benefit of statins in breast cancer is increasing. Currently, a total of 30 breast cancer/statin trials are listed at the global trial identifier website clinicaltrials.gov. Given the compelling evidence from performed trials in a variety of clinical settings, there have been calls for a clinical trial of statins in the adjuvant breast cancer setting. It would be imperative for such a trial to incorporate tumour biomarkers predictive of statin response in its design and analysis plan. Ongoing translational clinical trials aimed at biomarker discovery will help identify, which breast cancer patients are most likely to benefit from adjuvant statin therapy, and will add valuable clinical knowledge to the field.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Biomarcadores Tumorais/sangue , Neoplasias da Mama/sangue , Neoplasias da Mama/genética , Sobrevivência Celular/efeitos dos fármacos , Quimioterapia Adjuvante , Ensaios Clínicos como Assunto , Terapia Combinada , Feminino , Humanos , Recidiva Local de Neoplasia/prevenção & controle , Resultado do Tratamento
2.
Hum Reprod ; 33(3): 503-511, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29425332

RESUMO

STUDY QUESTION: Does phthalate exposure from prescription drugs affect semen quality? SUMMARY ANSWER: Exposure to phthalate-containing drugs is associated with poor semen quality. WHAT IS KNOWN ALREADY: Phthalates and their metabolites have been shown to disrupt the hormone signalling in animal studies. One study has shown associations between medicinal phthalate exposure and poor semen quality, suggesting similar effects in humans. STUDY DESIGN, SIZE, DURATION: We included 18 515 males with poor semen quality (cases) and 31 063 males with normal semen quality (controls) registered in the Danish IVF Registry from 2006 to 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Exposure to phthalate-containing drugs was assessed from the Danish Register of Medicinal Product Statistics. Outcome measures were obtained at the first contact with the fertility clinic, and categorized according to the International Classification of Diseases (ICD-10). The association between current use of phthalate-containing medications <90 days prior to semen sampling and reduced semen quality was analysed using unconditional logistic regression, adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 57 cases and 72 controls redeemed at least one prescription for a drug containing ortho-phthalates in the 90 days before their first semen sample, yielding an adjusted odds ratio (OR) of 1.30 (95% CI: 0.91-1.85) for poor semen quality when compared to males exposed to phthalate-free generic drugs. Similarly, 81 cases and 78 controls exposed to a drug containing polymers had increased odds of poor semen quality (OR = 1.71, 95% CI: 1.24-2.35). Current exposure to polymer containing products from alimentary tract and metabolism drugs was associated with the highest OR of 2.80 (95% CI: 1.63-4.84). Comparing males exposed to drugs containing ortho-phthalates or polymers with males unexposed to prescription drugs, we found adjusted ORs of 1.32 (95% CI: 0.93-1.87) and 1.73 (95% CI: 1.26-2.36), respectively. We saw no clear relationship between degree of exposure and odds of poor semen quality. LIMITATIONS, REASONS FOR CAUTION: The reliance on ICD-10 based register data restricted our ability to relate phthalate exposure to detailed semen parameters. Furthermore, due to imperfections in the registry, we could only include the first semen sample and could not follow semen quality over time. WIDER IMPLICATIONS OF THE FINDINGS: Our results support the likely negative effect of phthalate exposure from medicinal drugs on semen quality. As exposures from medicinal products are readily avoidable, our findings may be of relevance to regulatory authorities. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by Odense University Hospital, Denmark (Grant number A1003). None of the authors declare conflict of interest.


Assuntos
Exposição Ambiental , Fertilização in vitro , Ácidos Ftálicos/toxicidade , Medicamentos sob Prescrição/química , Espermatozoides/efeitos dos fármacos , Adulto , Dinamarca , Humanos , Masculino , Ácidos Ftálicos/análise , Sistema de Registros , Análise do Sêmen , Contagem de Espermatozoides
3.
Ann Oncol ; 25(12): 2419-2425, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25223486

RESUMO

BACKGROUND: Treatment with synthetic glucocorticoids (GCs) depresses the immune response and may therefore modify cancer outcomes. We investigated the association between GC use and breast cancer recurrence. MATERIALS AND METHODS: We conducted a population-based cohort study to examine the risk of breast cancer recurrence associated with GC use among incident stage I-III female breast cancer patients aged >18 years diagnosed 1996-2003 in Denmark. Data on patients, clinical and treatment factors, recurrence, and comorbidities as well as data on GC prescriptions and potential confounders were obtained from Danish population-based medical registries. GCs were categorized according to administrative route: systemic, inhaled, or intestinal. Women were followed for up to 10 years or until 31 December 2008. We used Cox proportional hazards regression models to compute hazard ratios (HRs) and associated 95% confidence intervals (95% CIs) to evaluate the association between GC use and recurrence. Time-varying drug exposures were lagged by 1 year. RESULTS: We included 18 251 breast cancer patients. Median recurrence follow-up was 6.9 years; 3408 women developed recurrence during follow-up. Four thousand six hundred two women filled at least one GC prescription after diagnosis. In unadjusted models, no association was observed among users of systemic, inhaled, and intestinal GCs (HRsystemic = 1.1, 95% CI 0.9-1.3; HRinhaled = 0.9, 95% CI 0.7-1.0; and HRintestinal = 1.0, 95% CI 0.9-1.2) versus nonusers. In adjusted models, the results were also near null (HRsystemic = 1.1, 95% CI 0.9-1.2; HRinhaled = 0.8, 95% CI 0.7-1.0; and HRintestinal = 1.0, 95% CI 0.8-1.2). CONCLUSION: We found no evidence of an effect of GC use on breast cancer recurrence.


Assuntos
Neoplasias da Mama/patologia , Glucocorticoides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Dinamarca , Feminino , Glucocorticoides/efeitos adversos , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva
4.
J Eur Acad Dermatol Venereol ; 27(11): 1440-3, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22691169

RESUMO

BACKGROUND: Diabetes and obesity are more prevalent amongst psoriasis patients as is disturbance of the innate immune system. GLP-1 analogue therapy considerably improves weight and glycaemic control in people with type 2 diabetes and its receptor is present on innate immune cells. OBJECTIVE: We aimed to determine the effect of liraglutide, a GLP-1 analogue, on psoriasis severity. METHODS: Before and after 10 weeks of liraglutide therapy (1.2 mg subcutaneously daily) we determined the psoriasis area and severity index (PASI) and the dermatology life quality index (DLQI) in seven people with both psoriasis and diabetes (median age 48 years, median body mass index 48.2 kg/m(2) ). We also evaluated the immunomodulatory properties of liraglutide by measuring circulating lymphocyte subset numbers and monocyte cytokine production. RESULTS: Liraglutide therapy decreased the median PASI from 4.8 to 3.0 (P = 0.03) and the median DLQI from 6.0 to 2.0 (P = 0.03). Weight and glycaemic control improved significantly. Circulating invariant natural killer T (iNKT) cells increased from 0.13% of T lymphocytes to 0.40% (P = 0.03). Liraglutide therapy also effected a non-significant 54% decrease in the proportion of circulating monocytes that produced tumour necrosis factor alpha (P = 0.07). CONCLUSION: GLP-1 analogue therapy improves psoriasis severity, increases circulating iNKT cell number and modulates monocyte cytokine secretion. These effects may result from improvements in weight and glycaemic control as well as from direct immune effects of GLP-1 receptor activation. Prospective controlled trials of GLP-1 therapies are warranted, across all weight groups, in psoriasis patients with and without type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Obesidade/complicações , Psoríase/tratamento farmacológico , Adulto , Idoso , Animais , Gatos , Feminino , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Humanos , Liraglutida , Masculino , Estudos Prospectivos , Psoríase/complicações
5.
Trials ; 23(1): 483, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35689289

RESUMO

BACKGROUND: Treatment of superficial venous reflux has been shown to improve ulcer healing time and reduce the risk of ulcer recurrence. Terminal ablation of the reflux source (TIRS) is an alternative to formal endovenous ablation or surgery which can be performed by injecting sclerosant foam into the peri-ulcer plexus of the veins. TIRS has been shown to be successful and in our experience is the option preferred by many patients, when offered as an alternative to axial ablation (AA). AIM: To determine if the proportion of ulcers healed within 6 months of endovenous treatment differs between patients undergoing AA of varicose veins or TIRS by peri-ulcer foam sclerotherapy. METHODS: AAVTIRS is an assessor-blinded randomised controlled trial. Patients will be recruited from a dedicated ulcer clinic in Roscommon University Hospital and from the vascular surgical clinics in University Hospital Galway. All patients attending the ulcer clinic will be screened for eligibility. RANDOMISATION: Random computer-generated sequence is stratified by ulcer size. Allocation will be concealed using sealed opaque envelopes. BLINDING: Assessors reviewing wounds at follow -p visits will be blinded to patient allocation. PRIMARY ENDPOINT: The proportion of ulcers healed within 6 months of enrolment. DISCUSSION: This will be the first time that TIRS has been evaluated with a properly powered randomised trial in the setting of venous ulcer management. Streamlining the management of venous ulcers has broad health economic benefits. If it is found that TIRS is superior or non-inferior to AA, then a less expensive, less invasive injection can be offered as an alternative to AA in an attempt to encourage the healing of venous ulcers. If AA is found to be superior to TIRS, then this would suggest that all patients undergoing ablation in the management of venous ulcers should have their superficial reflux fully treated, building on the evidence of the EVRA trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT04484168. Registered on 23 July 2020.


Assuntos
Úlcera Varicosa , Varizes , Humanos , Recidiva , Escleroterapia/efeitos adversos , Resultado do Tratamento , Úlcera/etiologia , Úlcera Varicosa/diagnóstico , Úlcera Varicosa/terapia , Varizes/terapia
6.
Diabetologia ; 54(11): 2745-54, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21744074

RESUMO

AIMS/HYPOTHESIS: The innate immune cells, invariant natural killer T cells (iNKT cells), are implicated in the pathogenesis of psoriasis, an inflammatory condition associated with obesity and other metabolic diseases, such as diabetes and dyslipidaemia. We observed an improvement in psoriasis severity in a patient within days of starting treatment with an incretin-mimetic, glucagon-like peptide-1 (GLP-1) receptor agonist. This was independent of change in glycaemic control. We proposed that this unexpected clinical outcome resulted from a direct effect of GLP-1 on iNKT cells. METHODS: We measured circulating and psoriatic plaque iNKT cell numbers in two patients with type 2 diabetes and psoriasis before and after commencing GLP-1 analogue therapy. In addition, we investigated the in vitro effects of GLP-1 on iNKT cells and looked for a functional GLP-1 receptor on these cells. RESULTS: The Psoriasis Area and Severity Index improved in both patients following 6 weeks of GLP-1 analogue therapy. This was associated with an alteration in iNKT cell number, with an increased number in the circulation and a decreased number in psoriatic plaques. The GLP-1 receptor was expressed on iNKT cells, and GLP-1 induced a dose-dependent inhibition of iNKT cell cytokine secretion, but not cytolytic degranulation in vitro. CONCLUSIONS/INTERPRETATION: The clinical effect observed and the direct interaction between GLP-1 and the immune system raise the possibility of therapeutic applications for GLP-1 in inflammatory conditions such as psoriasis.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Células T Matadoras Naturais/metabolismo , Psoríase/complicações , Psoríase/tratamento farmacológico , Receptores de Glucagon/metabolismo , Contagem de Células , Linhagem Celular , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/efeitos adversos , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1 , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Fatores Imunológicos/efeitos adversos , Fatores Imunológicos/farmacologia , Fatores Imunológicos/uso terapêutico , Liraglutida , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Células T Matadoras Naturais/efeitos dos fármacos , Células T Matadoras Naturais/imunologia , Obesidade/complicações , Psoríase/imunologia , Psoríase/metabolismo , RNA Mensageiro/metabolismo , Receptores de Glucagon/agonistas , Receptores de Glucagon/genética , Índice de Gravidade de Doença , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/imunologia , Pele/patologia
7.
Diabetes Res Clin Pract ; 173: 108685, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33548336

RESUMO

AIMS: Pre-gestational diabetes mellitus (PGDM) is associated with adverse outcomes. We aimed to examine pregnancies affected by PGDM; report on these pregnancy outcomes and compare outcomes for patients with type 1 versus type 2 diabetes mellitus; compare our findings to published Irish and United Kingdom (UK) data and identify potential areas for improvement. METHODS: Between 2016 and 2018 information on 679 pregnancies from 415 women with type 1 Diabetes Mellitus and 244 women with type 2 diabetes was analysed. Data was collected on maternal characteristics; pregnancy preparation; glycaemic control; pregnancy related complications; foetal and maternal outcomes; unscheduled hospitalisations; congenital anomalies and perinatal deaths. RESULTS: Only 15.9% of women were adequately prepared for pregnancy. Significant deficits were identified in availability and attendance at pre-pregnancy clinic, use of folic acid, attaining appropriate glycaemic targets and appropriate retinal screening. The majority of pregnancies (n = 567, 83.5%) resulted in a live birth but the large number of infants born large for gestational age (LGA) (n = 280, 49.4%), born prematurely <37 weeks and requiring neonatal intensive care unit (NICU) admission continue to be significant issues. CONCLUSIONS: This retrospective cohort study identifies multiple targets for improvements in the provision of care to women with pre-gestational DM which are likely to translate into better pregnancy outcomes.


Assuntos
Resultado da Gravidez , Gravidez em Diabéticas/diagnóstico , Gravidez em Diabéticas/epidemiologia , Adulto , Estudos de Coortes , Feminino , Humanos , Irlanda , Gravidez , Estudos Retrospectivos
8.
Science ; 228(4705): 1280-4, 1985 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-4001942

RESUMO

The mechanism of irreversible thermoinactivation of an enzyme has been quantitatively elucidated in the pH range relevant to enzymatic catalysis. The processes causing irreversible inactivation of hen egg-white lysozyme at 100 degrees C are deamidation of asparagine residues, hydrolysis of peptide bonds at aspartic acid residues., destruction of disulfide bonds, and formation of incorrect (scrambled) structures; their relative contributions depend of the pH.


Assuntos
Muramidase , Desnaturação Proteica , Animais , Asparagina , Galinhas , Dissulfetos , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética
10.
Br J Cancer ; 99(4): 616-21, 2008 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-18665165

RESUMO

Tamoxifen remains an important adjuvant therapy to reduce the rate of breast cancer recurrence among patients with oestrogen-receptor-positive tumours. Cytochrome P-450 2D6 metabolizes tamoxifen to metabolites that more readily bind the oestrogen receptor. This enzyme also metabolizes selective serotonin reuptake inhibitors (SSRI), so these widely used drugs - when taken concurrently - may reduce tamoxifen's prevention of breast cancer recurrence. We studied citalopram use in 184 cases of breast cancer recurrence and 184 matched controls without recurrence after equivalent follow-up. Cases and controls were nested in a population of female residents of Northern Denmark with stages I-III oestrogen-receptor-positive breast cancer 1985-2001 and who took tamoxifen for 1, 2, or most often for 5 years. We ascertained prescription histories by linking participants' central personal registry numbers to prescription databases from the National Health Service. Seventeen cases (9%) and 21 controls (11%) received at least one prescription for the SSRI citalopram while taking tamoxifen (adjusted conditional odds ratio=0.85, 95% confidence interval=0.42, 1.7). We also observed no reduction of tamoxifen effectiveness among regular citalopram users (>or=30% overlap with tamoxifen use). These results suggest that concurrent use of citalopram does not reduce tamoxifen's prevention of breast cancer recurrence.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Citalopram/uso terapêutico , Recidiva Local de Neoplasia/prevenção & controle , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Tamoxifeno/uso terapêutico , Adulto , Idoso , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Estudos de Casos e Controles , Quimioterapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Estadiamento de Neoplasias , Taxa de Sobrevida , Resultado do Tratamento
12.
Biochim Biophys Acta ; 616(2): 329-39, 1980 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-7213641

RESUMO

Enzymes capable of catalyzing the bromination of p-hydroxybenzyl alcohol by Br- have been shown to be present in crude homogenates of the alga Rhodomela larix (Rhodophyta). There are also indications of such activity in the marine invertebrates Thelepus setosus and Ptychodera flava laysanica. Detailed analysis of R. larix samples indicated that the activity in this species is greatest in the late spring and summer. After partial purification the enzyme had a pH optimum of approx. 4.4, a temperature optimum around 32 degrees C and was inhibited by NaN3. This algal bromoperoxidase requires the presence of H2O2 and can brominate monochlorodimedon and oxidize iodide, but it cannot oxidize chloride. The enzyme appears to be particulate.


Assuntos
Anelídeos/enzimologia , Peroxidases/metabolismo , Rodófitas/enzimologia , Animais , Álcoois Benzílicos , Digitonina/farmacologia , Ativação Enzimática/efeitos dos fármacos , Halogênios , Peroxidases/isolamento & purificação , Estações do Ano , Solubilidade , Espectrofotometria Ultravioleta
13.
Biochim Biophys Acta ; 378(2): 241-50, 1975 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-1125228

RESUMO

1. Cell-free systems from phytohaemagglutinin-stimulated pig lymphocytes are much more active in both endogenous protein synthesis and the translation of poly(U) than those from unstimulated lymphocytes. 2. Addition of tRNA stimulates the translation of poly(U) and greatly reduces the difference between systems from stimulated and unstimulated lymphocytes. Endogenous protein synthesis is not increased by added tRNA. 3. Systems from stimulated lymphocytes have an increased capacity to form aminoacyl-tRNA with several different amino acids. This reaction is limited by the amount of tRNA present in the cell-free system. 4. The rate of polypeptide elongation is not affected by lymphocyte stimulation. The increased rate of protein synthesis must therefore be due to an increase in the frequency of initiation of the synthesis of protein molecules.


Assuntos
Proteínas Sanguíneas/biossíntese , Lectinas/farmacologia , Linfócitos/metabolismo , Elongação Traducional da Cadeia Peptídica/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Aminoacil-tRNA Sintetases/metabolismo , Animais , Ativação Linfocitária , Linfócitos/efeitos dos fármacos , Magnésio/farmacologia , Poli U/metabolismo , Suínos , Aminoacilação de RNA de Transferência/efeitos dos fármacos
14.
Circulation ; 100(4): 369-75, 1999 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-10421596

RESUMO

BACKGROUND: Atrial arrhythmias occur commonly after cardiac surgery and are a cause of significant morbidity and increased hospital costs, yet there is no well-studied treatment strategy to deal with them expeditiously. The purpose of this study was to determine the efficacy and safety of ibutilide fumarate, an approved drug for the rapid conversion of atrial fibrillation and flutter, in patients after cardiac surgery. METHODS AND RESULTS: Patients with atrial fibrillation or flutter occurring 1 to 7 days after surgery and lasting 1 hour to 3 days were randomized to receive two 10-minute blinded infusions of placebo or 0.25, 0.5, or 1.0 mg of ibutilide fumarate. Treatment was considered successful if sinus rhythm was restored for any period of time by hour 1.5. A total of 302 patients were randomized, 201 with fibrillation and 101 with flutter. Treatment with ibutilide resulted in significantly higher conversion rates than placebo, and efficacy was dose related (placebo 15%; ibutilide 0.25 mg 40%, 0.5 mg 47%, and 1.0 mg 57%). Conversion rates at all doses were higher for atrial flutter than for atrial fibrillation. Mean time to conversion decreased as the dose was increased. Polymorphic ventricular tachycardia was the most serious adverse effect and occurred in 1.8% of the ibutilide-treated patients compared with 1.2% of patients who received placebo. CONCLUSIONS: Ibutilide is a useful and safe treatment alternative for the atrial arrhythmias that occur after cardiac surgery.


Assuntos
Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Flutter Atrial/tratamento farmacológico , Procedimentos Cirúrgicos Cardíacos , Complicações Pós-Operatórias/tratamento farmacológico , Sulfonamidas/uso terapêutico , Adulto , Antiarrítmicos/administração & dosagem , Antiarrítmicos/efeitos adversos , Fibrilação Atrial/etiologia , Fibrilação Atrial/fisiopatologia , Flutter Atrial/etiologia , Flutter Atrial/fisiopatologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Taquicardia Ventricular/induzido quimicamente
15.
J Am Coll Cardiol ; 27(5): 1112-8, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8609329

RESUMO

OBJECTIVES: The goals of this study were to determine the probability of successful defibrillation at the upper limit of vulnerability and to evaluate a minimal safety margin for implantable cardioverter-defibrillator first shocks based solely on the upper limit of vulnerability. BACKGROUND: The upper limit of vulnerability is the strength at or above which ventricular fibrillation is not induced when a stimulus is delivered during the vulnerable phase of the cardiac cycle. It has been proposed as an estimate of defibrillation efficacy because it correlates with the defibrillation threshold and can be determined with a single episode of fibrillation. METHODS: We studied 40 patients prospectively at implantation of transvenous cardioverter-defibrillators. Defibrillation threshold was defined as the weakest biphasic shock that defibrillated after 10 s of ventricular fibrillation. The upper limit of vulnerability was defined as the weakest biphasic shock that did not induce ventricular fibrillation when given at 0, 20 and 40 ms before the peak of the T wave in ventricular paced rhythm at cycle length 500 ms. After determination of the upper limit of vulnerability and defibrillation threshold, patients underwent six additional fibrillation-defibrillation episodes. The strength of five of the defibrillation shocks was equal to the upper limit of vulnerability; the strength of one of the six shocks was randomly selected to be equal to the upper limit of vulnerability plus 3 J. The implantable cardioverter-defibrillator was tested at the upper limit of vulnerability plus 3 J in 28 patients. RESULTS: The defibrillation threshold was 8.8 +/- 5.0 J (mean +/- SD), and upper limit of vulnerability was 11.3 +/- 4.6 J; the defibrillation threshold and upper limit of vulnerability were highly correlated (r = 0.89, p < 0.001). The success rate for the 200 defibrillation shocks with strength equal to the upper limit of vulnerability was 90% (95% confidence intervals based on proportion of successes in 40 patients: 86% to 94%). All five defibrillation test shocks at the upper limit of vulnerability were successful in 24 patients (60%); four of five were successful in 12 patients (30%); and three of five were successful in 4 patients (10%). All 40 test shocks and 28 implantable cardioverter-defibrillator shocks with a strength equal to the upper limit of vulnerability plus 3 J were successful. CONCLUSIONS: The upper limit of vulnerability is a good estimator of the shock strength associated with 90% probability of successful defibrillation (DFT90). A strength of 3 J above the upper limit of vulnerability is a good estimate of the minimal acute safety margin for implantable cardioverter-defibrillator first shocks.


Assuntos
Cardioversão Elétrica/métodos , Adulto , Idoso , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
16.
J Am Coll Cardiol ; 24(2): 416-24, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8034878

RESUMO

OBJECTIVES: The goal of this study was to determine the incidence and clinical significance of underdetection in 125 patients treated with a tiered-therapy cardioverter-defibrillator, the Medtronic PCD. BACKGROUND: Underdetection, distinct from undersensing, is a unique, potential complication of new algorithms that enhance specificity in tiered-therapy cardioverter-defibrillators. These algorithms may delay or prevent recognition of ventricular tachycardia even though electrograms are sensed accurately and RR intervals meet the programmed interval criterion. METHODS: Underdetection was defined as delay in detection > 5 s at electrophysiologic study or symptomatic delay or detection failure at follow-up of 15 +/- 8 months. RESULTS: We identified six specific mechanisms of underdetection caused by algorithms to discriminate sustained ventricular tachycardia from sinus tachycardia, atrial fibrillation, ventricular fibrillation and nonsustained ventricular tachycardia. Underdetection caused detection delays in 13 (1.9%) of 677 induced ventricular tachyarrhythmia episodes in 12 patients (9.6%). During follow-up, underdetection occurred in 7 (9.9%) of 71 patients in whom ventricular tachycardia therapies were programmed. Failure to detect ventricular tachycardia occurred in 6 (0.6%) of 988 spontaneous ventricular tachycardia episodes in four patients (5.6%); 2 episodes required external cardioversion. After defibrillator reprogramming, underdetection did not occur. CONCLUSIONS: Algorithms to enhance specificity cause underdetection of ventricular tachycardia in a significant minority of patients with tiered-therapy cardioverter-defibrillators. Optimal programming can minimize underdetection.


Assuntos
Algoritmos , Desfibriladores Implantáveis , Taquicardia Ventricular/diagnóstico , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Taquicardia Ventricular/terapia
17.
Arch Intern Med ; 143(1): 97-9, 1983 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6401420

RESUMO

The Denver Veterans Administration Medical Center (DVAMC) established a mobile internal medicine clinic (MediVAn) to provide access to primary care for veterans living more than fifty miles from the center and to study the costs of such an outreach program. A fully equipped van staffed by an internist visited four Colorado cities weekly for scheduled appointments. In the first two years of operation there were 4,655 visits by 766 veterans with a mean age of 56 years, with 3.9 diagnoses, and receiving 3.0 medicines. The cost per MediVAn visit was $68, compared with $67 per outpatient visit at DVAMC. We conclude that a mobile medical clinic is a convenient method of delivering primary care over distances and is comparable in cost to outpatient hospital visits.


Assuntos
Hospitais de Veteranos/organização & administração , Medicina Interna/tendências , Unidades Móveis de Saúde/organização & administração , Colorado , Análise Custo-Benefício , Atenção à Saúde/economia , Feminino , Hospitais com 300 a 499 Leitos , Humanos , Masculino , Pessoa de Meia-Idade , Unidades Móveis de Saúde/estatística & dados numéricos , População Rural
18.
Aust Vet J ; 93(4): 121-3, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25817977

RESUMO

OBJECTIVE: The objective of this study was to evaluate the effectiveness of an anti-gonadotropin-releasing factor vaccine in controlling sexual and aggressive behaviour of male pigs in the late finishing period under Australian field conditions. METHODS: Male pigs from four consecutive batches over a 4-month period were randomly assigned to two groups: an untreated control group (n = 434) or a group treated with Improvac® (n = 433). The vaccine was administered at 10 and 16 weeks of age. Pigs were housed under commercial conditions in ecoshelters, a commonly used housing system in Australia in which pigs are kept in large pens often containing >100 animals. The occurrence of sexual and aggressive behaviours was recorded and evaluated after second vaccination until slaughter at 22 weeks of age. RESULTS: Male pigs treated with Improvac demonstrated significant reductions in mounting, fighting, pushing, head butting and tail manipulation when compared with control animals. CONCLUSION: This study confirms that vaccination with Improvac can improve the welfare of entire male pigs by inhibiting sexual and aggressive behaviour.


Assuntos
Agressão/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Comportamento Sexual Animal/efeitos dos fármacos , Suínos/psicologia , Vacinas/uso terapêutico , Criação de Animais Domésticos/métodos , Animais , Austrália , Masculino
19.
QJM ; 108(3): 183-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25086107

RESUMO

BACKGROUND: People with severe obesity (body mass index [BMI] > 40 kg/m(2)) have an 85% higher mortality than people with a healthy BMI. Poor physical function may contribute to this excess mortality. Lymphoedema-like swelling can affect the legs of severely obese people with normal lymphoscintigraphy. AIM: We sought to determine the relationship between the presence of lymphoedema-like swelling and physical function in the severely obese. DESIGN AND METHODS: In people with severe obesity, we ascertained whether lower leg lymphoedema-like swelling was present and determined the circumference of the lower leg, time taken to ascend and descend a 17-cm step 50 times and time taken to walk 500 m. RESULTS: The 330 participants, 33% of whom were male, were aged 43.4 ± 12.7 years (mean ± standard deviation) and had a BMI of 51.7 ± 8.4 kg/m(2). Lymphoedema-like swelling was present in approximately one-third (n = 108) in whom a prior history of cellulitis and venous thromboembolism was more common (relative risks 6.16 and 3.86, respectively) than in those without lymphoedema-like swelling. Participants with lymphoedema-like swelling, compared with non-affected counterparts, had a higher lower leg circumference (35.0 ± 7.1 vs. 32.4 ± 4.8 cm), a slower step speed (0.40 ± 0.12 vs. 0.43 ± 0.10 steps/s) and a slower walking speed (0.97 ± 0.37 vs. 1.08 ± 0.30 m/s, P < 0.05 for all comparisons). CONCLUSIONS: In this cross-sectional study, 33% of our severely obese participants had lymphoedema-like swelling. Participants with lymphoedema-like swelling had worse physical function than those without. This association was independent of BMI. The presence of obesity-related chronic lymphoedema-like swelling should lead to interventions that improve physical function.


Assuntos
Linfedema/etiologia , Obesidade Mórbida/complicações , Caminhada/fisiologia , Adolescente , Adulto , Idoso , Índice de Massa Corporal , Doença Crônica , Estudos Transversais , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Perna (Membro) , Linfedema/fisiopatologia , Masculino , Anamnese/métodos , Pessoa de Meia-Idade , Obesidade Mórbida/fisiopatologia , Exame Físico/métodos , Adulto Jovem
20.
J Immunol Methods ; 10(4): 329-36, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-956665

RESUMO

Different grades of glass fibre filter paper have been compared for harvesting cells labelled with tritium using a semi-automatic harvester. Grade GF/C (Whatman Ltd) was selected for routine use although GF/B was found to be useful for whole blood cultures. The factors affecting the choice of thymidine concentration and activity are discussed and 1 mjCi or [3H]thymidine (5 Ci/mMol)/0.2 ml culture is shown to give a linear relationship with total DNA synthesis for up to 22 h.


Assuntos
DNA/biossíntese , Linfócitos/metabolismo , Animais , Contagem de Células/métodos , Células Cultivadas , Filtração/instrumentação , Vidro , Camundongos , Baço/citologia , Timidina/metabolismo , Trítio
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