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1.
J Toxicol Environ Health A ; 78(19): 1217-26, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26437174

RESUMEN

Fipronil is a pyrazole acaricide and insecticide that may be used for insect, tick, lice, and mite control on pets. Residents' short-term and long-term postapplication exposures to fipronil, including secondary environmental exposures, were estimated using data from chemical-specific studies. Estimations of acute (24-h) absorbed doses for residents were based on U.S. Environmental Protection Agency (U.S. EPA) 2012 standard operating procedures (SOPs) for postapplication exposure. Chronic exposures were not estimated for residential use, as continuous, long-term application activities were unlikely to occur. Estimated acute postapplication absorbed doses were as high as 0.56 µg/kg-d for toddlers (1-2 yr) in households with treated pets based on current U.S. EPA SOPs. Acute toddler exposures estimated here were fivefold larger in comparison to adults. Secondary exposure from the household environment in which a treated pet lives that is not from contacting the pet, but from contacting the house interior to which pet residues were transferred, was estimated based on monitoring socks worn by pet owners. These secondary exposures were more than an order of magnitude lower than those estimated from contacting the pet and thus may be considered negligible.


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Insecticidas/efectos adversos , Mascotas , Pirazoles/efectos adversos , Administración Cutánea , Administración Oral , Adulto , Animales , Gatos , Preescolar , Perros , Exposición a Riesgos Ambientales/estadística & datos numéricos , Composición Familiar , Femenino , Humanos , Lactante , Insecticidas/administración & dosificación , Masculino , Residuos de Plaguicidas/efectos adversos , Pirazoles/administración & dosificación
2.
Regul Toxicol Pharmacol ; 64(2): 263-6, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22922654

RESUMEN

Recent epidemiological studies have claimed to associate a variety of toxicological effects of organophosphorus insecticides (OPs) and residential OP exposure based on the dialkyl phosphates (DAPs; metabolic and environmental breakdown products of OPs) levels in the urine of pregnant females. A key premise in those epidemiology studies was that the level of urinary DAPs was directly related to the level of parent OP exposure. Specific chemical biomarkers and DAPs representing absorbed dose of OPs are invaluable to reconstruct human exposures in prospective occupational studies and even in non-occupational studies when exposure to a specific OP can be described. However, measurement of those detoxification products in urine without specific knowledge of insecticide exposure is insufficient to establish OP insecticide exposure. DAPs have high oral bioavailability and are ubiquitously present in produce at concentrations several-fold greater than parent OPs. Studies relying on DAPs as an indicator of OP exposure that lack credible information on proximate OP exposure are simply measuring DAP exposure and misattributing OP exposure.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/orina , Insecticidas/orina , Organofosfatos/orina , Biomarcadores/orina , Femenino , Humanos , Embarazo , Medición de Riesgo
3.
J Periodontal Res ; 45(5): 688-94, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20682019

RESUMEN

BACKGROUND AND OBJECTIVE: Epidemiological studies have established that patients with diabetes have an increased prevalence and severity of periodontal disease. Interleukin (IL)-6, a multifunctional cytokine, plays a role in the tissue inflammation that characterizes periodontal disease. Our recent study has shown a trend of increase in periodontal IL-6 expression at the mRNA level across patients with neither periodontal disease nor diabetes, patients with periodontal disease alone and patients with both diseases. However, the periodontal IL-6 expression at the protein level in these patients has not been investigated. MATERIAL AND METHODS: Periodontal tissue specimens were collected from eight patients without periodontal disease and diabetes (group 1), from 17 patients with periodontal disease alone (group 2) and from 10 patients with both periodontal disease and diabetes (group 3). The frozen sections were prepared from these tissue specimens and IL-6 protein expression was detected and quantified. RESULTS: The nonparametric Kruskal-Wallis test showed that the difference in IL-6 protein levels among the three groups was statistically significant (p = 0.035). Nonparametric analysis using the Jonckheere-Terpstra test showed a tendency of increase in periodontal IL-6 protein levels across group 1 to group 2 to group 3 (p = 0.006). Parametric analysis of variance (ANOVA) on IL-6 protein levels showed that neither age nor gender significantly affected the difference of IL-6 levels among the groups. CONCLUSION: Periodontal IL-6 expression at the protein level is increased across patients with neither periodontal disease nor diabetes, patients with periodontal disease alone and patients with both diseases.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Interleucina-6/biosíntesis , Enfermedades Periodontales/metabolismo , Adulto , Anciano , Análisis de Varianza , Estudios de Casos y Controles , Complicaciones de la Diabetes/metabolismo , Femenino , Expresión Génica , Humanos , Procesamiento de Imagen Asistido por Computador , Técnicas para Inmunoenzimas , Interleucina-6/análisis , Interleucina-6/genética , Masculino , Persona de Mediana Edad , Enfermedades Periodontales/complicaciones , Periodoncio/metabolismo , Estadísticas no Paramétricas
4.
Rev Environ Contam Toxicol ; 186: 107-32, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16676903

RESUMEN

Faced with the need to evaluate under what conditions chemicals can be used with "reasonable certainty of no harm" to workers and consumers, industry and government agencies have embraced quantitative risk analysis as a science-based approach for product development, regulatory evaluations, and associated risk management decision making. Beginning in the 1990s, a variety of industry-sponsored task forces have been formed to develop exposure-related data to support safety evaluations for pesticide chemicals used in agricultural, industrial, institutional, residential, and other settings. Human exposure assessment and the underlying data (e.g., personal exposure and biological monitoring measurements, media-specific residue measurements, product use, and time-activity information) represent a critical component of the risk assessment process and a rapidly advancing science. While task forces have been created to develop databases for supporting the continued safe use of products, the development of these databases has served to advance general understanding of the basic principles underlying exposure assessment methodology and thereby provide the basis for improved science-based risk management by both industry and government. Given that developing chemical-specific data for every product use pattern and associated worker or consumer exposure scenario (e.g., professional mixer, loader and applicator activities associated with the use of a low-pressure sprayer, consumer residential lawn application via a ready-to-use hose-end sprayer product) is prohibitively expensive and time consuming, alternative approaches have been developed based upon meta-analyses and generalizations derived from databases of exposure monitoring studies for multiple chemicals, sorted by significant exposure covariates such as formulation type, method of application, amount of active ingredient applied, site of application, protective equipment and clothing, and task or activity. These generalizations can be used for predictive exposure analyses and have clearly demonstrated the value of "generic databases." Although data in these databases and associated generalizations are subject to interpretation, e.g., during the regulatory decision-making processes, and may be used in conjunction with additional considerations or assessment methods that result in conservative biases, the role of generic databases for risk management decision making, and advancing the science of applied exposure analysis continues to be realized.


Asunto(s)
Bases de Datos Factuales , Exposición a Riesgos Ambientales/efectos adversos , Monitoreo del Ambiente/métodos , Plaguicidas/efectos adversos , Adulto , Niño , Femenino , Humanos , Masculino , Riesgo
5.
J Med Biogr ; 24(2): 215-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-24658212

RESUMEN

Elizabeth Gaskell had several relatives who were doctors, two of whom became well known, and she met many practitioners and specialists. This led to interesting portraits of doctors in her novels and also leads to speculation as to why she includes some real individuals and certain diagnoses and why she gave herself a poor prognosis.


Asunto(s)
Literatura Moderna/historia , Medicina en la Literatura , Inglaterra , Historia del Siglo XIX
6.
J Appl Phys ; 120(7)2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-28781380

RESUMEN

The influence of grain constraint on the magnetic field levels required to complete the isothermal martensitic transformation in magnetic shape memory alloys has been demonstrated for a NiCoMnSn alloy, and the magnetocaloric performance of an optimally heat treated alloy was quantified. Ni45CoxMn45-xSn10 melt spun ribbons with x = 2, 4, 5, and 6 were characterized. The x = 5 sample was determined to exhibit the lowest transformation thermal hysteresis (7 K) and transformation temperature range during transformation from paramagnetic austenite to nonmagnetic martensite, as well as a large latent heat of transformation (45 J kg-1 K-1). For this composition, it was found that increasing the grain size to thickness ratio of the ribbons from 0.2 to 1.2, through select heat treatments, resulted in a decrease in the magnetic field required to induce the martensitic transformation by about 3 T due to the corresponding reduction in the martensitic transformation temperature range. This decrease in the field requirement ultimately led to a larger magnetocaloric entropy change achieved under relatively smaller magnetic field levels. The giant inverse magnetocaloric effect of the optimized alloy was measured and showed that up to 25 J kg-1 K-1 was generated by driving the martensitic transition with magnetic fields up to 7 T.

7.
Urology ; 50(1): 110-2, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9218028

RESUMEN

OBJECTIVES: Snodgrass recently described a form of urethral tubularization with longitudinal incision of the urethral plate to create an elliptical meatus. To prevent fistulae, a transverse island of dorsal subcutaneous tissue was used to cover the repair. The generation of this flap may compromise blood supply to the skin that is used in the skin closure, and predispose to penile torsion. We have modified the technique to address these concerns, while accomplishing the major goal of functional success-particularly minimizing or eliminating fistulae. METHODS: Eighteen boys, aged 6 months to 6 years, with distal or midshaft hypospadias, underwent a one-stage repair using a modification of Snodgrass' technique. Rather than a transverse island flap of subcutaneous tissue, a local de-epithelialized skin flap was used to cover the urethroplasty. RESULTS: Sixteen patients have returned for follow-up, and all patients have an excellent cosmetic and functional result with an elliptical glanular meatus. There have been no cases of fistula or meatal stenosis. CONCLUSIONS: Distal hypospadias repair utilizing a de-epithelialized local skin flap to cover a tubularized incised urethral plate gives an excellent cosmetic and functional result. Optimal blood supply to the ultimate skin coverage is preserved, and penile torsion is avoided.


Asunto(s)
Hipospadias/cirugía , Colgajos Quirúrgicos/métodos , Niño , Preescolar , Humanos , Lactante , Masculino , Pene/cirugía , Uretra/cirugía
8.
Urology ; 46(4): 559-61, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7571229

RESUMEN

OBJECTIVES: To evaluate the effectiveness of percutaneous endoscopy of the tunica vaginalis for identifying testicular torsion in a rodent model. METHODS: One testis was randomly selected in 10 Wistar rats weighing 500 to 600 g. Following 2 hours of 720 degree torsion, bilateral percutaneous endoscopy of the tunica vaginalis was performed by a blinded investigator utilizing a 70 degree cystoscope lens through a single midline 3 to 4 mm scrotal cutdown incision. RESULTS: Using this technique, the blinded investigator was able to identify the torsed testis rapidly in every case, which was distinguished by its cyanotic color and by the size and color of the testicular surface vessels. CONCLUSIONS: Tunica vaginoscopy is a simple, accurate, rapidly performed, minimally invasive, diagnostic technique in this experimental model of testicular torsion.


Asunto(s)
Torsión del Cordón Espermático/diagnóstico , Animales , Endoscopía , Masculino , Distribución Aleatoria , Ratas , Ratas Wistar
9.
Urol Clin North Am ; 27(3): 393-402, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10985140

RESUMEN

Pheochromocytoma is a rare but important tumor in children. Appropriate evaluation and management are essential for a favorable outcome. Pheochromocytomas are more often multifocal and extra-adrenal in children when compared with adults. This pattern makes the diagnosis, localization, and surgical management more challenging. Nonetheless, the standard biochemical evaluation is usually diagnostic, and MR imaging is currently the best tool for tumor localization. The possibility of a familial syndrome must always be considered and should always be thoroughly evaluated when children present with a pheochromocytoma. Conversely, children with a familial syndrome should undergo annual screening for pheochromocytoma from a young age. Given the greater likelihood of a metachronous recurrence in children, consideration should be given to adrenal-sparing surgery in selected patients. When managed appropriately, the outlook for pheochromocytoma in children is excellent. Unfortunately, the uncommon malignant tumors are still difficult to treat. Perhaps the unique genetic characteristics of pheochromocytoma will ultimately be exploited in the management of the aggressive forms of this disease.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales , Feocromocitoma , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de las Glándulas Suprarrenales/terapia , Catecolaminas/metabolismo , Niño , Humanos , Feocromocitoma/diagnóstico , Feocromocitoma/metabolismo , Feocromocitoma/terapia , Enfermedad de von Hippel-Lindau/complicaciones
10.
Urol Clin North Am ; 25(2): 219-25, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9633577

RESUMEN

UPJ obstructions occurring in anomalous kidneys require special consideration. Many anomalous kidneys are dysmorphic with extrarenal pelves, making the distinction between obstructed and nonobstructed hydronephrosis crucial. The radiographic evaluation must be thorough because there are often other associated anomalies of the ipsilateral or contralateral kidney. Operative intervention must be tailored to the specifics of the case. Although most UPJ obstructions in anomalous kidneys can be reconstructed successfully with dismembered pyeloplasty or treated with newer minimally invasive techniques, issues regarding access, operative detail, and adjunct procedures make these cases challenging for the urologic surgeon.


Asunto(s)
Coristoma , Riñón/anomalías , Obstrucción Ureteral/diagnóstico , Obstrucción Ureteral/cirugía , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino
11.
Urol Clin North Am ; 25(2): 211-7, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9633576

RESUMEN

The treatment of UPJ obstruction in children should be approached in a fashion that recognizes the differences between children and adults. Radiographic definition of the urinary tract is different in children than in adults because of the size of the child and technical difficulties with instrumentation. Retrograde pyelography, in general, is not necessary in children, although this decision must be individualized. The surgical incision should be chosen based on the size of the child and the unique considerations of individual renal anatomy and pathology, as well as the surgeon's experience. In children, tubeless surgery may be performed with excellent results, however, diversion with nephrostomies and stents may be necessary in selected cases. With attention to technical details and the unique considerations in children, the results of repair of the UPJ should be excellent and reproducible.


Asunto(s)
Obstrucción Ureteral/cirugía , Niño , Femenino , Humanos , Hidronefrosis/etiología , Lactante , Recién Nacido , Masculino , Nefrostomía Percutánea , Stents , Obstrucción Ureteral/complicaciones , Obstrucción Ureteral/diagnóstico , Urografía
12.
Rev Environ Contam Toxicol ; 128: 1-15, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1410686

RESUMEN

Pesticide use is inevitably associated with chemical exposures that range from inferred nondetectable levels to easily measurable ones using sensitive, readily available analytical tools. Whether these exposures are of any biological significance is determined by duration, dose, and biological reactivity. The overwhelming majority of human exposures occur in a diverse chemical milieu of a nutritive substances and are of no known significance. Technologies that minimize human chemical exposures and maximize pesticide effectiveness are favored. The risk characterization process is ideally suited to assist decision makers concerning the protection of human health and evaluation of agricultural tools. It is the best means available to balance the review of pesticide impacts on health and agriculture. Regulators must be cautious to acknowledge the relative rather than absolute nature of the risk characterization process. Workplace biological monitoring must become more commonplace as a means to evaluate the chemical exposure potential of various work tasks and greater attention must be given to the biological validation of methods. Earlier needs for data to develop workplace hygiene strategies have been replaced in recent years by demands of the risk assessment process, which utilizes direct estimates of exposure and absorbed dose. Animal models, no matter how attractive, are not presently a substitute for human experience. Opportunities to gather more information on human experience associated with pesticide exposures must be more aggressively identified and pursued. Only a very small time lag should exist between identification of pesticide metabolites in rats and evaluation of metabolic similarities in humans. At the present levels of analytical sensitivity, most of our current uncertainty about the extent of worker exposure and patterns of metabolism between species can be at least clarified with the cooperation of persons who are exposed during normal day-to-day activities in the workplace. Only with better human data will the risk assessment process warrant greater reliance in decision making concerning our chemical exposures and human experience.


Asunto(s)
Exposición a Riesgos Ambientales , Plaguicidas , Humanos , Exposición Profesional , Factores de Riesgo
13.
J Expo Anal Environ Epidemiol ; 10(1): 50-7, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10703847

RESUMEN

Current methods of estimating absorbed dosage (AD) of chemicals were evaluated to determine residue transfer from a carpet treated with chlorpyrifos (CP) to humans who performed a structured exercise routine. To determine the dislodgeability of residue, a California Department of Food and Agriculture (CDFA) roller was applied to a flat cotton cloth upon a treated carpet. Levels ranged from 0.06 to 0.99 microg CP/cm2. Cotton whole body dosimeters (WBD) were also used to assess residue transfer. The dosimeters retained 1.5 to 38 mg CP/person. Urine biomonitoring (3 days) for 3,5,6-trichloro-2-pyridinol (TCP) of persons who wore only swimsuits revealed a mean AD of 176 microg CP equivalents/person. The results show that the AD depends on the extent of contact transfer and dermal absorption of the residue. Default exposure assessments based upon environmental levels of chemicals and hypothetical transport pathways predict excessive exposure. The cotton WBD retains chemical residues and may be effectively used to predict dermal dose under experimental conditions.


Asunto(s)
Cloropirifos/análisis , Exposición a Riesgos Ambientales/análisis , Insecticidas/análisis , Xenobióticos/análisis , Administración Cutánea , Adsorción , Adulto , Vestuario , Ejercicio Físico , Pisos y Cubiertas de Piso , Gossypium , Humanos
14.
J Pediatr Surg ; 32(12): 1759-60, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9434021

RESUMEN

Surgical treatment of the children of Jehovah's Witnesses is a challenging problem both ethically and technically. The authors recently operated on such a child who had bilateral Wilms' tumors. Techniques used to minimize blood loss included erythropoietin, hemodilution, and the argon beam coagulator. A full understanding of the religious, legal, and ethical issues is essential when treating the children of Jehovah's Witnesses.


Asunto(s)
Cristianismo , Neoplasias Renales/cirugía , Religión y Medicina , Tumor de Wilms/cirugía , Preescolar , Femenino , Hemodilución , Hemostasis Quirúrgica/métodos , Humanos , Neoplasias Primarias Múltiples/cirugía
15.
J Pediatr Surg ; 35(10): 1426-30, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11051142

RESUMEN

PURPOSE: The aim of this study is to report the initial experience with needlescopic surgery (2-mm optics and instrumentation exclusively) for the cryptorchid testicle. METHODS: Ten patients (age 8 months to 37 years) underwent 12 needlescopic procedures: orchiopexy (n = 8), orchiectomy (n = 2), and diagnostic exploration with attempted excision of testicular remnant (n = 2). Two patients underwent bilateral needlescopic orchiopexy. Needlescopic (2 mm) optics and instrumentation were used exclusively in the pediatric patients. RESULTS: All procedures were completed successfully by needlescopic techniques. Mean surgical time was 110 minutes (range, 60 to 180 minutes), and blood loss was 6 mL (range, 0 to 20 mL). There were no intraoperative complications. All procedures were performed on an outpatient basis. In all 8 orchidopexies, the testis was successfully brought to a scrotal position. CONCLUSIONS: Needlescopic techniques allow safe performance of various procedures for a cryptorchid testicle. The cosmetic result is excellent.


Asunto(s)
Criptorquidismo/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Adulto , Niño , Endoscopios , Humanos , Lactante , Recién Nacido , Laparoscopía/métodos , Masculino , Orquiectomía , Testículo/cirugía
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