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1.
Climacteric ; 18(3): 343-5, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25966859

RESUMEN

The impact of the findings from the Women's Health Initiative trial of estrogen plus progestin cannot be attributed to any real or imagined conflicts of interest between government, researchers, and journals. Rather, the findings overturned decades of dogma in part promoted by the pharmaceutical industry, and the reaction to these unexpected findings was in direct proportion to their importance in reversing a misguided practice of prescribing the drug for chronic disease prevention. The findings have been widely accepted, as shown by the sustained subsequent reduction in prescriptions. However, conflicts of interest may influence a minority unwilling to accept the findings. The decrease in the use of a drug with an adverse risk profile for prevention of chronic disease is a public good.


Asunto(s)
Investigación Biomédica/economía , Conflicto de Intereses , Gobierno , Investigadores/ética , Apoyo a la Investigación como Asunto , Humanos
2.
Climacteric ; 18(3): 336-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25966858

RESUMEN

In an invited editorial, Dr Shapiro proposes that vaginal bleeding leading to unblinding and subsequent detection bias explains the breast cancer increase seen with estrogen plus progestin in the Women's Health Initiative (WHI) clinical trial (1) . In the context of a uniform detection program of protocol-mandated annual mammography and breast examinations, such a proposal is medically implausible. Dr Shapiro suggests detection bias would identify a larger number of 'slowly growing tumors that would otherwise remain clinically silent'. The findings of more advanced cancers with increased deaths from breast cancer in the estrogen plus progestin group refute this conjecture. During early post-intervention phases of both WHI hormone therapy trials, when breast cancer detection bias is asserted by Dr Shapiro because participants had been informed of randomization assignment, breast cancer incidence rates were lower (rather than higher) than during intervention. Thus, Dr Shapiro's claims are directly refuted by findings from the WHI randomized clinical trials. Health-care providers should be aware that randomized clinical trial evidence supports estrogen plus progestin increasing breast cancer incidence and deaths from breast cancer. In contrast, among women with prior hysterectomy, randomized clinical trial evidence supports estrogen alone reducing breast cancer incidence and deaths from breast cancer.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/mortalidad , Terapia de Reemplazo de Estrógeno/métodos , Estrógenos/uso terapéutico , Progestinas/uso terapéutico , Sesgo , Femenino , Humanos , Mamografía , Posmenopausia , Ensayos Clínicos Controlados Aleatorios como Asunto
3.
Contemp Clin Trials ; 142: 107564, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38704119

RESUMEN

INTRODUCTION: Women with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS) have a significantly increased risk of breast cancer, which can be substantially reduced with antiestrogen therapy for chemoprevention. However, antiestrogen therapy for breast cancer risk reduction remains underutilized. Improving knowledge about breast cancer risk and chemoprevention among high-risk patients and their healthcare providers may enhance informed decision-making about this critical breast cancer risk reduction strategy. METHODS/DESIGN: We are conducting a cluster randomized controlled trial to evaluate the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. We have cluster randomized 26 sites across the U.S. through the SWOG Cancer Research Network. A total of 415 patients and 200 healthcare providers are being recruited. They are assigned to standard educational materials alone or combined with the web-based decision support tools. Patient-reported and clinical outcomes are assessed at baseline, after a follow-up visit at 6 months, and yearly for 5 years. The primary outcome is chemoprevention informed choice after the follow-up visit. Secondary endpoints include other patient-reported outcomes, such as chemoprevention knowledge, decision conflict and regret, and self-reported chemoprevention usage. Barriers and facilitators to implementing decision support into clinic workflow are assessed through patient and provider interviews at baseline and mid-implementation. RESULTS/DISCUSSION: With this hybrid effectiveness/implementation study, we seek to evaluate if a multi-level intervention effectively promotes informed decision-making about chemoprevention and provide valuable insights on how the intervention is implemented in U.S. TRIAL REGISTRATION: NCT04496739.


Asunto(s)
Neoplasias de la Mama , Quimioprevención , Humanos , Femenino , Neoplasias de la Mama/prevención & control , Quimioprevención/métodos , Educación del Paciente como Asunto/métodos , Técnicas de Apoyo para la Decisión , Persona de Mediana Edad , Adulto , Toma de Decisiones , Conocimientos, Actitudes y Práctica en Salud , Conducta de Reducción del Riesgo , Proyectos de Investigación , Antagonistas de Estrógenos/uso terapéutico , Antagonistas de Estrógenos/administración & dosificación , Medición de Resultados Informados por el Paciente
4.
Osteoporos Int ; 24(2): 567-80, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23208074

RESUMEN

SUMMARY: The Women's Health Initiative (WHI) double-blind, placebo-controlled clinical trial randomly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D(3) daily or placebo, with average intervention period of 7.0 years. The trial was designed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture, and secondarily, total fracture and colorectal cancer. INTRODUCTION: This study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data, with emphasis on fractures, cardiovascular disease, cancer, and total mortality. METHODS: WHI calcium and vitamin D randomized clinical trial (CT) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation, and these data were contrasted and combined with corresponding data from the WHI prospective observational study (OS). RESULTS: Among women not taking personal calcium or vitamin D supplements at baseline, the hazard ratio [HR] for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 (95 % confidence interval (CI), 0.38-1.00). In combined analyses of CT and OS data, the corresponding HR was 0.65 (95 % CI, 0.44-0.98). Supplementation effects were not apparent on the risks of myocardial infarction, coronary heart disease, total heart disease, stroke, overall cardiovascular disease, colorectal cancer, or total mortality, while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive. CONCLUSION: Though based primarily on a subset analysis, long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women. Other health benefits and risks of supplementation at doses considered, including an elevation in urinary tract stone formation, appear to be modest and approximately balanced.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Carbonato de Calcio/uso terapéutico , Colecalciferol/uso terapéutico , Suplementos Dietéticos/efectos adversos , Fracturas Osteoporóticas/prevención & control , Anciano , Conservadores de la Densidad Ósea/administración & dosificación , Conservadores de la Densidad Ósea/efectos adversos , Carbonato de Calcio/administración & dosificación , Carbonato de Calcio/efectos adversos , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Colecalciferol/administración & dosificación , Colecalciferol/efectos adversos , Método Doble Ciego , Esquema de Medicación , Quimioterapia Combinada , Femenino , Fracturas de Cadera/epidemiología , Fracturas de Cadera/etiología , Fracturas de Cadera/prevención & control , Humanos , Persona de Mediana Edad , Neoplasias/epidemiología , Neoplasias/prevención & control , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/tratamiento farmacológico , Osteoporosis Posmenopáusica/epidemiología , Fracturas Osteoporóticas/epidemiología , Medición de Riesgo/métodos , Estados Unidos/epidemiología , Cálculos Urinarios/inducido químicamente , Cálculos Urinarios/epidemiología
5.
J Food Prot ; 69(3): 660-5, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16541700

RESUMEN

An estimated 2,500 cases of listeriosis occur annually in the United States. Listeriosis is particularly severe among pregnant women and immunocompromised individuals. Little is known regarding the effect of the food matrix on the ability of L. monocytogenes to survive in the gastrointestinal tract and cause systemic infection. Mice were inoculated with various doses of L. monocytogenes in skim milk, Half & Half, or whipping cream to determine whether differences in milk fat content influence the ability of L. monocytogenes to survive passage through the gut and infect the liver or spleen. The number of fecal samples positive for L. monocytogenes increased with increasing doses of L. monocytogenes for all three vehicles. The number of L. monocytogenes cells isolated from liver or spleen of mice dosed with L. monocytogenes was not significantly different among treatment vehicles. Dose-response models revealed that as the dosage of L. monocytogenes was increased in different milk vehicles, the number of L. monocytogenes cells in liver or spleen also increased. Although fat content of food had no dose-dependent effect on L. monocytogenes infection in the murine gastrointestinal tract, we cannot discount the possibility that it may be a factor in L. monocytogenes infections of humans because of differences in the physiology of gastrointestinal tracts of mice and humans.


Asunto(s)
Grasas de la Dieta/farmacología , Listeria monocytogenes/crecimiento & desarrollo , Listeria monocytogenes/patogenicidad , Listeriosis/microbiología , Leche/química , Animales , Recuento de Colonia Microbiana , Modelos Animales de Enfermedad , Heces/microbiología , Femenino , Humanos , Listeria monocytogenes/efectos de los fármacos , Hígado/microbiología , Ratones , Ratones Endogámicos BALB C , Organismos Libres de Patógenos Específicos , Bazo/microbiología
6.
J Natl Cancer Inst ; 108(3)2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26668177

RESUMEN

BACKGROUND: While progestin addition to estrogen mitigates endometrial cancer risk, the magnitude of the effect on incidence, specific endometrial cancer histologies, and endometrial cancer mortality remains unsettled. These issues were assessed by analyses after extended follow-up of the Women's Health Initiative (WHI) randomized clinical trial evaluating continuous combined estrogen plus progestin use. METHODS: The WHI enrolled 16 608 postmenopausal women into a randomly assigned, double-blind, placebo-controlled trial. Women age 50 to 79 years with intact uteri with normal endometrial biopsy at entry were randomly assigned to once-daily 0.625 mg conjugated equine estrogen plus 2.5mg medroxyprogesterone acetate (n = 8506) as a single pill or matching placebo (n = 8102). Follow-up beyond the original trial completion date required reconsent, obtained from 12 788 (83%) of surviving participants. Analyses were by intent-to-treat. All statistical tests were two-sided. RESULTS: After 5.6 years' median intervention and 13 years' median cumulative follow-up, there were fewer endometrial cancers in the combined hormone therapy compared with the placebo group (66 vs 95 case patients, yearly incidence, 0.06% vs 0.10%; hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.48 to 0.89, P = .007). While there were somewhat fewer endometrial cancers during intervention (25 vs 30, respectively; HR = 0.77, 95% CI = 0.45 to 1.31), the difference became statistically significant postintervention (41 vs 65, respectively; HR = 0.59, 95% CI = 0.40 to 0.88, P = .008), but hazard ratios did not differ between phases (P difference = .46). There was a statistically nonsignificant reduction in deaths from endometrial cancer in the estrogen plus progestin group (5 vs 11 deaths, HR = 0.42, 95% CI = 0.15 to 1.22). CONCLUSION: In postmenopausal women, continuous combined estrogen plus progestin decreases endometrial cancer incidence.


Asunto(s)
Neoplasias Endometriales/inducido químicamente , Neoplasias Endometriales/epidemiología , Terapia de Reemplazo de Estrógeno , Estrógenos Conjugados (USP)/administración & dosificación , Estrógenos Conjugados (USP)/efectos adversos , Acetato de Medroxiprogesterona/administración & dosificación , Acetato de Medroxiprogesterona/efectos adversos , Anciano , Método Doble Ciego , Esquema de Medicación , Neoplasias Endometriales/mortalidad , Neoplasias Endometriales/cirugía , Terapia de Reemplazo de Estrógeno/efectos adversos , Terapia de Reemplazo de Estrógeno/métodos , Femenino , Humanos , Histerectomía , Incidencia , Estimación de Kaplan-Meier , Persona de Mediana Edad , Oportunidad Relativa , Posmenopausia , Estados Unidos/epidemiología , Salud de la Mujer
7.
Circulation ; 99(15): 1997-2002, 1999 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-10209004

RESUMEN

BACKGROUND: Antiphospholipid (aPL) antibodies are associated with thrombosis in patients diagnosed with antiphospholipid syndrome (APS) and enhance thrombus formation in vivo in mice, but the mechanism of thrombosis by aPL is not completely understood. Although aPL antibodies have been shown to inhibit protein C activation and activate endothelial cells (ECs) in vitro, no study has examined whether these antibodies activate ECs in vivo. Therefore, human affinity-purified aPL (ap aPL) antibodies from APS patients were tested in a mouse model of microcirculation using the cremaster muscle that allows direct microscopic examination of thrombus formation and adhesion of white blood cells (WBCs) to ECs as an indication of EC activation in vivo. Adhesion molecule expression on human umbilical vein endothelial cells (HUVECs) after aPL exposure was performed to confirm EC activation in vitro. METHODS AND RESULTS: All 6 ap aPL antibodies significantly increased the expression of VCAM-1 (2.3- to 4.4-fold), with one of the antibodies also increasing the expression of E-selectin (1.6-fold) on HUVECs in vitro. In the in vivo experiments, each ap aPL antibody except for 1 preparation increased WBC sticking (mean number of WBCs ranged from 22.7 to 50.6) compared with control (14.4), which correlated with enhanced thrombus formation (mean thrombus size ranged from 1098 to 6476 versus 594 microm2 for control). CONCLUSIONS: Activation of ECs by aPL antibodies in vivo may create a prothrombotic state on ECs, which may be the first pathophysiological event of thrombosis in APS.


Asunto(s)
Anticuerpos Antifosfolípidos/farmacología , Síndrome Antifosfolípido/inmunología , Enfermedades Autoinmunes/inmunología , Endotelio Vascular/efectos de los fármacos , Trombofilia/etiología , Adulto , Animales , Anticuerpos Antifosfolípidos/inmunología , Especificidad de Anticuerpos , Síndrome Antifosfolípido/fisiopatología , Enfermedades Autoinmunes/fisiopatología , Adhesión Celular , Células Cultivadas , Relación Dosis-Respuesta Inmunológica , Selectina E/análisis , Endotelio Vascular/citología , Endotelio Vascular/fisiología , Femenino , Glicoproteínas/inmunología , Humanos , Inmunización Pasiva , Inmunoglobulina G/farmacología , Molécula 1 de Adhesión Intercelular/análisis , Inhibidor de Coagulación del Lupus/inmunología , Inhibidor de Coagulación del Lupus/farmacología , Masculino , Ratones , Microcirculación/efectos de los fármacos , Trombosis/etiología , Molécula 1 de Adhesión Celular Vascular/análisis , beta 2 Glicoproteína I
8.
J Clin Oncol ; 11(9): 1729-36, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8355040

RESUMEN

PURPOSE: Hepatic venoocclusive disease (VOD) is a common complication of cytoreductive therapy for marrow transplantation. Only 25% of patients who develop VOD have severe disease. We tested the hypothesis that early clinical signs of VOD would predict which patients would recover and which would die. PATIENTS AND METHODS: We evaluated 355 consecutive patients who had transplants between August 6, 1987 and July 21, 1988 for occurrence of VOD and whether it was reversible within 100 days of transplant. Total serum bilirubin and weight gain from day -7 through day +16 posttransplant were compared among patients with no, severe, or nonsevere VOD. Logistic regression models were developed to estimate probabilities of severe VOD at each of six time intervals. The accuracy of these models was tested by applying them to 392 consecutive patients who underwent transplantation between July 22, 1988 and July 20, 1989. RESULTS: As early as day -1, bilirubin and weight gain were significantly different between patients whose VOD proved to be severe and patients with reversible VOD or no disease. Regression models were used to generate coefficients (beta 0, beta 1, beta 2) for the equation P = 1/(1 + e-z), where P is the probability of severe VOD and z = beta 0 + beta 1 (In total serum bilirubin [mg/dL]) + beta 2 (percent weight gain). Application of this equation to the next 392 patients allowed us to calculate sensitivity, specificity, and positive predictive value for a range of probabilities. CONCLUSION: The course of VOD after cytoreductive therapy can be predicted by knowing the serum bilirubin and weight gained within 1 to 2 weeks of transplantation. Probability estimates derived from patient data are highly specific and moderately sensitive. Such probability estimates may be useful when considering potentially risky interventions to treat VOD, such as recombinant human tissue plasminogen activator.


Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Enfermedad Veno-Oclusiva Hepática/mortalidad , Adolescente , Adulto , Bilirrubina/sangre , Trasplante de Médula Ósea/fisiología , Niño , Preescolar , Enfermedad Veno-Oclusiva Hepática/etiología , Humanos , Lactante , Modelos Logísticos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Probabilidad , Análisis de Regresión , Sensibilidad y Especificidad , Factores de Tiempo , Aumento de Peso
9.
Hypertension ; 17(3): 317-22, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1999362

RESUMEN

Vascular pressures were measured in the principal (A1) arteriole and in upstream small arteries of the rat cremaster muscle to investigate vascular resistance changes associated with one-kidney, one clip Goldblatt hypertension. Pressure measurements were made at a proximal and distal site of each vessel using a servonull micropipette system. Vessel diameters were measured using video microscopy. A1 arteriole and external spermatic artery diameters were both decreased after 2 and 4 weeks of hypertension. Mean arterial pressure was elevated after 2 weeks of hypertension (106 +/- 4 mm Hg versus 140 +/- 5 mm Hg). Likewise, vascular pressures were elevated at every site: pudicepigastric artery (36%), external spermatic artery (47%), and A1 arteriole (38%). The pressure drop along the external spermatic artery was increased (87%) after 2 weeks of hypertension. Mean arterial pressure was further elevated from 2-4 weeks of hypertension (105 +/- 4 mm Hg versus 162 +/- 7 mm Hg) but only the proximal pudic-epigastric artery pressure was further elevated during this time from 2 to 4 weeks (131 +/- 5 mm Hg versus 147 +/- 7 mm Hg) of hypertension development. This was associated with an increased pressure drop (87%) along the artery compared with the situation at 2 weeks. These data indicate that small arteries upstream from the microcirculation contribute significantly to the increase in vascular resistance during hypertension. In addition, these data indicate that the increases in small artery resistance do not develop uniformly throughout all vessel branches.


Asunto(s)
Hipertensión Renal/fisiopatología , Resistencia Vascular , Animales , Arteriolas/patología , Arteriolas/fisiopatología , Presión Sanguínea , Hipertensión Renal/patología , Masculino , Ratas , Ratas Endogámicas
10.
J Med Chem ; 24(11): 1271-7, 1981 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7310802

RESUMEN

A new series of methylase inhibitors has been designed in which the nucleophilic methyl acceptor is attached to the adenosine and/or homocysteine fragments of the methyl donor, S-adenosylmethionine, to form a "multisubstrate adduct". In the present case, catecholamine analogues attached through a phenethyl sulfide linkage to 5'-thioadenosine or homocysteine have been synthesized, together with the corresponding methylsulfonium salts. These compounds were assayed as inhibitors of catechol O-methyltransferase, and the adenosylsulfonium salts (4) were found to be inhibitors of the enzyme.


Asunto(s)
Inhibidores de Catecol O-Metiltransferasa , Compuestos Onio/síntesis química , Compuestos de Sulfonio/síntesis química , Fenómenos Químicos , Química , Compuestos de Sulfonio/farmacología
11.
J Clin Epidemiol ; 46(5): 455-9, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8501471

RESUMEN

In the general population, the use of stamps rather than business reply postage significantly improves response rates in mail surveys. Among physicians, however, a smaller effect might be anticipated due to their greater sophistication. An experiment was conducted to test the hypothesis that stamps would improve response rates and lower costs in a physician survey that included intensive follow up. In 1989, 380 physicians who reported providing primary care were surveyed. The protocol included two mailings, a postcard reminder, and two telephone reminders. Physicians were randomly assigned to receive a return envelope with a first-class stamp or an envelope that had been preprinted "business reply mail" in the first and second mailings. Response rates, calculated as completed surveys divided by eligible physicians, were 83.8 and 72.1% for stamps and business reply respectively, a difference of 11.7 percentage points (p < 0.01). Moreover, the total cost per completed survey was $11.18 for the physicians receiving stamps and $14.25 for the physicians receiving business reply. As in mail surveys of the general public, the use of first-class stamps on return envelopes both improves response rates and reduces cost in surveys of physicians.


Asunto(s)
Recolección de Datos/métodos , Médicos de Familia/psicología , Servicios Postales , Recolección de Datos/economía , Humanos , Médicos de Familia/economía , Médicos de Familia/estadística & datos numéricos , Distribución Aleatoria , Sistemas Recordatorios , Encuestas y Cuestionarios/economía , Washingtón
12.
Shock ; 4(6): 411-4, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8608397

RESUMEN

Endothelins (ET) have been demonstrated to mediate intestinal microvascular constriction during acute Escherichia coli bacteremia, however, their role during chronic infection is unknown. The purpose of this study was to determine whether ET-1 is synthesized in the small intestine in a more chronic peritonitis model. ET-1 mRNA levels of the terminal ileum in mice following cecal ligation and puncture (CLP) were compared to sham-operated animals and normal unoperated animals. ET gene expression was analyzed using differential reverse transcriptase chain reaction (RT-PCR) with co-amplification of beta-actin as an internal standard. To assess ET peptide expression, serum and intestinal tissue levels were measured using a specific enzyme immunoassay (ELISA). The pattern of ET-1 gene expression post-CLP with a single puncture of the cecum with a 23 ga. needle demonstrated a 3.6-fold increase at 8 h, and a return to sham levels by 24 h (374 +/- 64% at 8 h, p < .05, 128 +/- 13%). An increase of mRNA levels at 24 h post-CLP was observed with a double puncture with an 18 ga. needle (230 +/- 36%, p < .05) accompanied by an increase in serum ET levels (270 +/- 31%, p < .05) and higher tissue ET levels. These data indicate a time-dependent response of ET-1 gene expression in the terminal ileum post-CLP which is related to severity of infection.


Asunto(s)
Endotelinas/metabolismo , Intestino Delgado/metabolismo , Peritonitis/metabolismo , ARN Mensajero/metabolismo , Animales , Secuencia de Bases , Enfermedad Crónica , Modelos Animales de Enfermedad , Endotelinas/genética , Expresión Génica , Intestino Delgado/irrigación sanguínea , Masculino , Ratones , Microcirculación , Datos de Secuencia Molecular , Peritonitis/fisiopatología
13.
Bone Marrow Transplant ; 11(5): 389-93, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8504273

RESUMEN

Colligative cryoprotectants must be non-toxic at the high concentrations required for protection of cells from freeze-injury. Human hematopoietic stem cells are usually cryopreserved in a solution containing 1.6 molal (10% v/v) DMSO. We studied the chemical toxicity of this agent to myeloid and erythroid progenitor cells from healthy donors. No DMSO toxicity was found at concentrations of 5% or 10% at either 4 degrees or 37 degrees C for incubation durations up to 1 h. DMSO at 20% did not decrease the number of progenitor cell-derived colonies per 5 x 10(4) cells cultured, but did result in cell clumping during DMSO washout, resulting in a net loss of progenitor cells. At a concentration of 40% DMSO, a direct toxicity to hematopoietic progenitors was found. Delay in removal of DMSO after thawing of cryopreserved cells for periods up to 1 h was also non-toxic to hematopoietic progenitor cells. Direct addition of DMSO at 1% or 10% final concentration (v/v) to the culture dishes suppressed colony formation. These data suggest that DMSO is not toxic to haematopoietic progenitor cells after short-term exposure at the concentrations used for cryopreservation of marrow and peripheral blood stem cells.


Asunto(s)
Ensayo de Unidades Formadoras de Colonias , Dimetilsulfóxido/efectos adversos , Células Madre Hematopoyéticas/efectos de los fármacos , Agregación Celular , Células Madre Hematopoyéticas/citología , Humanos , Temperatura , Factores de Tiempo , Conservación de Tejido
14.
Surgery ; 106(1): 94-9, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2525821

RESUMEN

Oxygen microelectrodes were used to measure tumor partial pressure of oxygen (PO2) before and after photodynamic therapy (PDT) in a rat transplantable subcutaneous chondrosarcoma. Before PDT there was a gradient of PO2 from the superficial layers of the tumor (PO2 = 46 +/- 6 mm Hg) toward the center of the tumor (PO2 = 10 +/- 1 mm Hg). Mean tumor PO2 (21 +/- 2 mm Hg) was significantly reduced to 3 +/- 1 mm Hg 1 hour after PDT, and this reduction in PO2 persisted 4 hours (8 +/- 2 mm Hg) and 24 hours (6 +/- 1 mm Hg) after PDT. The largest percentage decrease in PO2 occurred at a depth of only 50 microns into the tumor. Inasmuch as PDT has been shown to decrease blood flow, our data suggest that PDT actions on blood vessels in the peripheral areas of the tumor are of major importance for eliciting the tumor hypoxia that contributes to tumor necrosis after PDT.


Asunto(s)
Antineoplásicos/uso terapéutico , Condrosarcoma/tratamiento farmacológico , Hematoporfirinas/uso terapéutico , Fotoquimioterapia , Sarcoma Experimental/tratamiento farmacológico , Animales , Condrosarcoma/metabolismo , Femenino , Derivado de la Hematoporfirina , Luz , Oxígeno/análisis , Consumo de Oxígeno , Presión Parcial , Ratas , Ratas Endogámicas , Sarcoma Experimental/metabolismo
15.
Am J Trop Med Hyg ; 58(6): 828-34, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9660474

RESUMEN

The effect of skin application of N,N-diethyl-m-toluamide (DEET) on the penetration and migration behavior of cercariae of Schistosoma mansoni was evaluated in vitro and in vivo in a mouse model. These studies showed that DEET at concentrations of 7.5% or higher was 100% effective in immobilizing and killing cercariae of S. mansoni in vitro. Ultrastructural studies on such DEET-exposed cercariae showed transformative and degenerative changes involving both tegument and deeper parenchymal structures. Fatal tissue lesions were evident as early as 5 min postexposure to DEET, and became more extensive with increasing exposure time. Cutaneous application of DEET (as a pure chemical in isopropanol or as a commercial insect repellent preparation) was more than 99% effective in preventing entry of S. mansoni cercariae into the mouse tail skin. Radiolabeling and tracer studies confirmed that 7.5% DEET applied to the skin prior to infection was highly effective in preventing schistosomular migration to the lungs.


Asunto(s)
DEET/uso terapéutico , Repelentes de Insectos/uso terapéutico , Schistosoma mansoni/efectos de los fármacos , Esquistosomiasis mansoni/prevención & control , Administración Tópica , Animales , DEET/administración & dosificación , DEET/farmacología , Modelos Animales de Enfermedad , Repelentes de Insectos/administración & dosificación , Repelentes de Insectos/farmacología , Masculino , Ratones , Microscopía Electrónica , Schistosoma mansoni/fisiología , Schistosoma mansoni/ultraestructura , Piel/parasitología
16.
J Am Coll Surg ; 185(1): 80-6, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9208966

RESUMEN

BACKGROUND: Blunt carotid artery trauma remains a rare but potentially devastating injury. Early detection and treatment remain the goals of management. Our objective was to identify patients sustaining blunt carotid injuries at a regional trauma center and report on the incidence, demographics, diagnostic workup, management, and outcome. STUDY DESIGN: A retrospective chart review was performed of patients sustaining blunt carotid artery injury between 1990 and 1996. RESULTS: Twenty patients were identified during the 7-year period. All patients suffered blunt trauma, with motor vehicle accidents being the most common mechanism, and the internal carotid the most frequently injured vessel. Associated injuries were present in all patients, with head (65%) or chest (65%) injuries being the most common. The combination of head and chest trauma (45%) was found to be associated with a 14-fold increase in the likelihood of carotid injury. Cerebral angiography was diagnostic in all patients and the majority were treated nonoperatively with anticoagulation. Twenty percent of patients were discharged with a normal neurologic exam, while 45% left with a significant neurologic deficit. Overall mortality was 5%. CONCLUSIONS: Blunt carotid injuries are rare but are associated with significant morbidity and mortality. The combination of craniofacial and chest wounds should raise the index of suspicion for blunt carotid injury. Anticoagulation was associated with the least morbidity.


Asunto(s)
Traumatismos de las Arterias Carótidas , Heridas no Penetrantes/diagnóstico , Heridas no Penetrantes/terapia , Adolescente , Adulto , Angiografía , Arterias Carótidas/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico , Riesgo , Factores de Riesgo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Heridas no Penetrantes/fisiopatología
17.
J Am Coll Surg ; 179(3): 305-12, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7520807

RESUMEN

BACKGROUND: The primary effect sought with most topical wound therapy is antimicrobial. Topical wound agents are thought to promote normal healing by protecting the wound from infection. In this study, we examined the effect of six commonly used topical wound agents (bacitracin, sodium hypochlorite, silver nitrate, silver sulfadiazine, mafenide acetate, and povidone-iodine) on epithelialization and neovascularization in noninfected wounds. For this study, a new wound model was used in which direct visualization and quantification of wound epithelialization and neovascularization were carried out throughout the entire healing process. STUDY DESIGN: We measured the effect which 500 U per g of bacitracin, 0.25 percent of sodium hypochlorite, 0.5 percent silver nitrate, 1 percent silver sulfadiazine, 8.5 percent mafenide acetate, and 10 percent povodione-iodine had on the rate of wound epithelialization and neovascularization. The agents were applied topically to 99 circular full-thickness wounds (2.25 mm diameter, 0.125 mm depth) created on the dorsum of male hairless mouse ears. This model enabled us to visualize and measure directly wound epithelialization and neovascularization repeatedly throughout healing, using intravital video microscopy and computerized digitized planimetry. RESULTS: Control wounds and wounds treated with silver sulfadiazine (n = 18) and mafenide acetate (n = 14) epithelialized in 7.2 +/- 0.7, 7.1 +/- 0.3, and 7.3 +/- 0.3 days, respectively. This was significantly (p < 0.01) faster than the wounds treated with povidone-iodine (n = 10), sodium hypochlorite, (n = 8), and bacitracin (n = 13). Wounds treated with povidone-iodine epithelialized the slowest (11.8 +/- 0.55 days). Wound neovascularization was completed most rapidly in the groups treated with povidone-iodine and silver sulfadiazine (15.0 +/- 0.4 and 15.3 +/- 0.7 days, respectively). This was significantly (p < 0.05) faster than wounds treated with silver nitrate (n = 15), which neovascularized in 18.4 +/- 0.56 days. One-half of the wounds treated with sodium hypochlorite (eight of 16) did not epithelialize or neovascularize. CONCLUSIONS: The various antimicrobial agents studied in our in vivo model affect wound epithelialization and neovascularization differently. These effects on these two very important aspects of healing should be taken into consideration when indicating a specific agent for treatment of different types of wounds.


Asunto(s)
Antiinfecciosos/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Antiinfecciosos/uso terapéutico , Epitelio/irrigación sanguínea , Epitelio/efectos de los fármacos , Mafenida/farmacología , Masculino , Ratones , Ratones Pelados , Neovascularización Patológica , Povidona Yodada/farmacología , Nitrato de Plata/farmacología , Sulfadiazina de Plata/farmacología , Hipoclorito de Sodio/farmacología , Factores de Tiempo
18.
J Orthop Res ; 17(4): 571-7, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10459764

RESUMEN

We investigated whether ischemic preconditioning induces microvascular protection in skeletal muscle at the late phase (after 24 hours) when the same muscles are subjected to prolonged warm global ischemia. The cremaster muscle of the male Sprague-Dawley rat underwent vascular isolation and was subjected to 4 hours of ischemia and 60 minutes of reperfusion. Early preconditioning consisted of 45 minutes of ischemia followed by 15 minutes of reperfusion before prolonged ischemia/reperfusion; late preconditioning also consisted of 45 minutes of ischemia but was done 24 hours (24-hour period of reperfusion) before the prolonged ischemia/reperfusion. Arteriole diameters and capillary perfusion were measured with use of intravital microscopy. Four groups were compared: rats that underwent early preconditioning, their controls, rats that underwent late preconditioning, and their controls. Early and late preconditioning significantly attenuated vasospasm and capillary no-reflow compared with the controls for each. Average arteriole diameter was significantly larger in the rats that underwent late preconditioning than in any other rats; it was also significantly larger in the controls for late preconditioning than in those for early preconditioning. We introduce a model of the rat cremaster muscle that has been isolated from its vascular supply as a useful preparation to study the effects of late preconditioning on microcirculation in skeletal muscle. Late preconditioning provided better microvascular protection than did early preconditioning. The mechanism for this preconditioning protection is being investigated because it should provide a means for therapeutic intervention.


Asunto(s)
Precondicionamiento Isquémico , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/inervación , Animales , Masculino , Microcirculación/anatomía & histología , Microcirculación/fisiología , Desnervación Muscular , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
19.
Am J Surg ; 174(3): 347-50, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9324152

RESUMEN

BACKGROUND: Previous studies using systematically administered lathyrogens to inhibit wound contractures have produced inconsistent results. The purpose of this study was to investigate the effects of lathyrogenic drugs on wound contraction when injected locally. METHODS: Two symmetrical full-thickness wounds were made on the dorsum of either side of hairless (hr/hr) mice; thus, each animal served as its own control. Animals were divided into groups receiving daily local injections of beta-aminopropionitrile or D-penicillamine, or both beta-aminopropionitrile and D-penicillamine and normal saline vehicle (control side) for 5 or 10 days. The rate of contraction was determined by serial measurements of the surface area of each wound during the treatment period. At the end of the treatment period, the wounds were excised en bloc with the chest wall and prepared for blinded histological analysis. Granulation tissue thickness, number of fibroblasts in granulation tissue per unit area, number of inflammatory cells (neutrophils, lymphocytes, macrophages and mast cells) in subjacent muscle per unit area, and collagen deposition in subjacent muscle were determined. RESULTS: Wound contraction, granulation tissue thickness, and collagen deposition in subjacent muscle were decreased only in wounds treated with beta-aminopropionitrile plus D-penicillamine. Collagen deposition in subjacent muscle was also decreased in wounds treated with D-penicillamine alone. Neither drug alone nor the combination affected the number of inflammatory cells in subjacent muscle. Body weight was not affected by the experimental procedures. CONCLUSIONS: The combination of beta-aminopropionitrile and D-penicillamine is potentially useful for inhibiting contracture formation when injected locally.


Asunto(s)
Aminopropionitrilo/uso terapéutico , Contractura/prevención & control , Penicilamina/uso terapéutico , Heridas y Lesiones/complicaciones , Análisis de Varianza , Animales , Colágeno/análisis , Contractura/etiología , Combinación de Medicamentos , Fibroblastos , Tejido de Granulación/anatomía & histología , Inyecciones Intralesiones , Masculino , Ratones , Ratones Pelados , Músculo Esquelético/química , Músculo Esquelético/inmunología
20.
J Am Diet Assoc ; 92(5): 553-9, 1992 May.
Artículo en Inglés | MEDLINE | ID: mdl-1573135

RESUMEN

The Women's Health Trial (WHT) was a feasibility study for a randomized trial of a low-fat diet for the prevention of breast cancer. One year after the WHT was terminated, a random sample of 894 participants who had been active in the WHT for an average of 16 months (range = 5 to 37) completed questionnaires about their dietary habits (a 21-item instrument that measures five dimensions of low-fat dietary habits) and food intake (a food frequency questionnaire). Women who participated in the intervention program maintained most of the low-fat dietary habits adopted during the study: mean total fat intake increased from 37.8 g to 41.0 g and scales describing substitution of specially manufactured low-fat foods and modification of meats to be lower in fat increased only slightly (by 0.11 and 0.14, respectively, on a scale of 1 = always to 4 = never). Scales describing avoiding meat and avoiding fats as a flavoring increased by 0.23 and 0.22, respectively, which suggests some recidivism. Women in the control group lowered their dietary fat intake from 65.0 to 57.5 g, but all differences in fat intake and fat-related dietary habits scales between women in the control and intervention groups remained highly statistically significant. In multiple regression models, all five low-fat dietary habits scales were independently associated with percentage of energy from fat, but the strongest association was for avoiding fats as flavorings. These results suggest that substitutions of specially manufactured low-fat foods are easily adopted and maintained dietary changes, but that maintenance of new habits related to avoiding fats as flavorings and avoiding meat will require long-term reinforcement strategies.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Neoplasias de la Mama/prevención & control , Grasas de la Dieta/administración & dosificación , Conducta Alimentaria , Anciano , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Encuestas y Cuestionarios
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