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1.
Ear Hear ; 40(6): 1418-1424, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30998550

RESUMEN

OBJECTIVES: To evaluate the influence of auditory cues on postural sway in normal-hearing (NH) individuals, hearing-impaired individuals with vestibular impairment (HIVL), or hearing-impaired (HI) individuals without vestibular impairment. DESIGN: Thirty-two participants received a hearing and a vestibular evaluation (vHIT, oVEMP, cVEMP) and then were separated in to three groups (NH, HI, HIVL). All participants had to stand on a force platform in four postural conditions (A: EO/firm, B: EC/firm, C: EO/Foam, D: EC/Foam) under two auditory conditions, with or without auditory cues. RESULTS: Results revealed that first, there was a significant difference between HIVL and both HI and NH groups in conditions C and D without auditory cues. Second, greater improvement for HIVL compared to NH and HI groups in condition C and D was observed with auditory cues. Finally, somatosensory reliance significantly decreased for the HIVL participants using hearing aids compared to NH and HI. CONCLUSIONS: Our results suggest that hearing aids benefit for postural control may be modulated by vestibular function.


Asunto(s)
Audífonos , Pérdida Auditiva/rehabilitación , Equilibrio Postural/fisiología , Enfermedades Vestibulares/fisiopatología , Adulto , Audiometría , Estudios de Casos y Controles , Señales (Psicología) , Femenino , Prueba de Impulso Cefálico , Pérdida Auditiva/complicaciones , Pérdida Auditiva/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Vestibulares/complicaciones , Potenciales Vestibulares Miogénicos Evocados , Vestíbulo del Laberinto/fisiología , Vestíbulo del Laberinto/fisiopatología , Adulto Joven
2.
Trends Hear ; 28: 23312165241232219, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38356376

RESUMEN

Recent studies suggest that sound amplification via hearing aids can improve postural control in adults with hearing impairments. Unfortunately, only a few studies used well-defined posturography measures to assess balance in adults with hearing loss with and without their hearing aids. Of these, only two examined postural control specifically in the elderly with hearing loss. The present study examined the impact of hearing aid use on postural control during various sensory perturbations in older adults with age-related hearing loss. Thirty individuals with age-related hearing impairments and using hearing aids bilaterally were tested. Participants were asked to perform a modified clinical sensory integration in balance test on a force platform with and without hearing aids. The experiment was conducted in the presence of a broadband noise ranging from 0.1 to 4 kHz presented through a loudspeaker. As expected, hearing aid use had a beneficial impact on postural control, but only when visual and somatosensory inputs were both reduced. Data also suggest that hearing aid use decreases the dependence on somatosensory input for maintaining postural control. This finding can be of particular importance in older adults considering the reduction of tactile and proprioceptive sensitivity and acuity often associated with aging. These results provide an additional argument for encouraging early hearing aid fitting for people with hearing loss.


Asunto(s)
Sordera , Audífonos , Pérdida Auditiva , Humanos , Anciano , Señales (Psicología) , Pérdida Auditiva/diagnóstico , Equilibrio Postural
3.
Toxicol Ind Health ; 28(9): 796-819, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22064681

RESUMEN

There is accumulating epidemiological evidence that exposure to some solvents, metals, asphyxiants and other substances in humans is associated with an increased risk of acquiring hearing loss. Furthermore, simultaneous and successive exposure to certain chemicals along with noise can increase the susceptibility to noise-induced hearing loss. There are no regulations that require hearing monitoring of workers who are employed at locations in which occupational exposure to potentially ototoxic chemicals occurs in the absence of noise exposure. This project was undertaken to develop a toxicological database allowing the identification of possible ototoxic substances present in the work environment alone or in combination with noise exposure. Critical toxicological data were compiled for chemical substances included in the Quebec occupational health regulation. The data were evaluated only for noise exposure levels that can be encountered in the workplace and for realistic exposure concentrations up to the short-term exposure limit or ceiling value (CV) or 5 times the 8-h time-weighted average occupational exposure limit (TWA OEL) for human data and up to 100 times the 8-h TWA OEL or CV for animal studies. In total, 224 studies (in 150 articles of which 44 evaluated the combined exposure to noise and a chemical) covering 29 substances were evaluated using a weight of evidence approach. For the majority of cases where potential ototoxicity was previously proposed, there is a paucity of toxicological data in the primary literature. Human and animal studies indicate that lead, styrene, toluene and trichloroethylene are ototoxic and ethyl benzene, n-hexane and p-xylene are possibly ototoxic at concentrations that are relevant to the occupational setting. Carbon monoxide appears to exacerbate noise-induced hearing dysfunction. Toluene interacts with noise to induce more severe hearing losses than the noise alone.


Asunto(s)
Pérdida Auditiva Provocada por Ruido/inducido químicamente , Audición/efectos de los fármacos , Exposición Profesional/efectos adversos , Solventes/toxicidad , Animales , Derivados del Benceno/toxicidad , Daño del ADN/efectos de los fármacos , Hexanos/toxicidad , Humanos , Ruido/efectos adversos , Quebec , Medición de Riesgo , Estireno/toxicidad , Tolueno/toxicidad , Tricloroetileno/toxicidad , Lugar de Trabajo , Xilenos/toxicidad
4.
Plant Methods ; 18(1): 96, 2022 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-35902871

RESUMEN

BACKGROUND: Characterizing plant genetic resources and their response to the environment through accurate measurement of relevant traits is crucial to genetics and breeding. Spatial organization of the maize ear provides insights into the response of grain yield to environmental conditions. Current automated methods for phenotyping the maize ear do not capture these spatial features. RESULTS: We developed EARBOX, a low-cost, open-source system for automated phenotyping of maize ears. EARBOX integrates open-source technologies for both software and hardware that facilitate its deployment and improvement for specific research questions. The imaging platform consists of a customized box in which ears are repeatedly imaged as they rotate via motorized rollers. With deep learning based on convolutional neural networks, the image analysis algorithm uses a two-step procedure: ear-specific grain masks are first created and subsequently used to extract a range of trait data per ear, including ear shape and dimensions, the number of grains and their spatial organisation, and the distribution of grain dimensions along the ear. The reliability of each trait was validated against ground-truth data from manual measurements. Moreover, EARBOX derives novel traits, inaccessible through conventional methods, especially the distribution of grain dimensions along grain cohorts, relevant for ear morphogenesis, and the distribution of abortion frequency along the ear, relevant for plant response to stress, especially soil water deficit. CONCLUSIONS: The proposed system provides robust and accurate measurements of maize ear traits including spatial features. Future developments include grain type and colour categorisation. This method opens avenues for high-throughput genetic or functional studies in the context of plant adaptation to a changing environment.

5.
Med Phys ; 36(2): 317-28, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19291971

RESUMEN

The continual need for more accurate and effective techniques in radiation therapy makes it necessary to devise new control means combining high spatial resolution as well as high dose accuracy. Intensity modulated radio therapy (IMRT) allows highly conformed fields with high spatial gradient and therefore requires a precise monitoring of all the multileaf positions. In response to this need, the authors have developed a new 2D tissue equivalent dosimeter with high spatial resolution. A plastic scintillator sheet is sandwiched between two polystyrene blocks and the emitted light is captured by a high resolution camera. A newly developed procedure described herein allows efficient discrimination of the scintillation from the parasitic Cerenkov radiation. This processing is applied on the cumulated image from a sequence of images taken during an irradiation field at a rate of 10 images/s. It provides a high resolution mapping of the cumulated dose in quasireal time. The dosimeter is tissue equivalent (ICRU-44) and works both for electrons and photons without complex parameter adjustment since phantom and detector materials are identical. Instrument calibration is simple and independent of the irradiation conditions (energy, fluence, quality, ...). In this article, the authors present the principle of the dosimeter and its calibration procedure. They compare the results obtained for photons and electron beams with ionization chamber measurements in polystyrene. Technical specifications such as accuracy and repeatability are precisely evaluated and discussed. Finally, they present different IMRT field measurements and compare DOSIMAP measurements to TPS simulations and dosimetric film profiles. The results confirm the excellent spatial resolution of the instrument and its capacity to inspect the leaf positions for each segment of a given field.


Asunto(s)
Radiometría/instrumentación , Radioterapia de Intensidad Modulada/métodos , Electrones , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Fotones , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/efectos adversos , Reproducibilidad de los Resultados , Riesgo , Sensibilidad y Especificidad
6.
Occup Environ Med ; 66(5): 319-24, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19174422

RESUMEN

OBJECTIVES: Our main purpose was to investigate any relationship between noise exposure levels in the workplace, degree of hearing loss (HL), and the relative risk of accident (OR of single or multiple events). METHODS: We conducted a retrospective study of 52 982 male workers aged 16-64 years with long-standing exposures to occupational noise over a 5-year period, using "hearing status" and "noise exposure" from the registry held by the Quebec National Institute of Public Health. Information on work-related accidents was obtained from the Quebec Workers' Compensation Board. Hearing threshold level measurements and noise exposures were regressed on the numbers of accidents after adjusting for age. RESULTS: Exposure to extremely noisy environments (L(eq8h) (equivalent noise level for 8 h exposure) > or =90 dBA) is associated with a higher relative risk of accident. The severity of hearing impairment (average bilateral hearing threshold levels at 3, 4 and 6 kHz) increases the relative risk of single and multiple events when threshold levels exceed 15 dB of hearing loss. The relative risk of multiple events (four or more) is approximately three times higher among severely hearing-impaired workers who are exposed to L(eq8h) > or =90 dBA. CONCLUSION: Single and multiple events are associated with high noise exposure and hearing status. This suggests that reducing noise exposure contributes to increased safety in noisy industries and prevents hearing loss. Hearing-impaired workers assigned to noisy workstations should be provided with assistive listening devices and efficient communication strategies should be implemented.


Asunto(s)
Accidentes de Trabajo/estadística & datos numéricos , Pérdida Auditiva Provocada por Ruido/epidemiología , Ruido en el Ambiente de Trabajo/estadística & datos numéricos , Enfermedades Profesionales/epidemiología , Exposición Profesional/estadística & datos numéricos , Adolescente , Adulto , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Masculino , Persona de Mediana Edad , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Quebec/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
7.
Bone Joint J ; 101-B(9): 1107-1114, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31474140

RESUMEN

AIMS: The aim of this study was to evaluate the differences in revision and complication rates, functional outcomes, and radiological outcomes between cemented and press-fit humeral stems in primary anatomical total shoulder arthroplasty (TSA). MATERIALS AND METHODS: A comprehensive systematic review and meta-analysis was conducted searching for studies that included patients who underwent primary anatomical TSA for primary osteoarthritis or rheumatoid arthritis. RESULTS: There was a total of 36 studies with 927 cemented humeral stems and 1555 press-fit stems. The revision rate was 5.4% (95% confidence interval (CI) 3.9 to 7.4) at a mean of 89 months for cemented stems, and 2.4% (95% CI 1.1 to 4.7) at a mean of 40 months for press-fit stems. A priori subgroup analysis to control for follow-up periods demonstrated similar revision rates: 2.3% (95% CI 1.1 to 4.7) for cemented stems versus 1.8% (95% CI 1.4 to 2.9) for press-fit stems. Exploratory meta-regression found that longer follow-up was a moderating variable for revision (p = 0.003). CONCLUSION: Cement fixation had similar revision rates when compared to press-fit stems at short- to midterm follow-up. Rotator cuff pathology was a prevalent complication in both groups but is likely not related to fixation type. Overall, with comparable revision rates, possible easier revision, and decreased operative time, humeral press-fit fixation may be an optimal choice for primary anatomical TSA in patients with sufficient bone stock. Cite this article: Bone Joint J 2019;101-B:1107-1114.


Asunto(s)
Artroplastía de Reemplazo de Hombro/efectos adversos , Artroplastía de Reemplazo de Hombro/métodos , Húmero/cirugía , Osteoartritis/cirugía , Articulación del Hombro/cirugía , Prótesis de Hombro/efectos adversos , Cementos para Huesos , Cementación , Humanos , Complicaciones Posoperatorias , Falla de Prótesis , Recuperación de la Función , Reoperación , Resultado del Tratamiento
8.
Med Phys ; 35(5): 1651-62, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18561640

RESUMEN

New radiation therapy techniques such as IMRT present significant efficiency due to their highly conformal dose distributions. A consequence of the complexity of their dose distributions (high gradients, small irradiation fields, low dose distribution, ...) is the requirement for better precision quality assurance than in classical radiotherapy in order to compare the conformation of the delivered dose with the planned dose distribution and to guarantee the quality of the treatment. Currently this control is mostly performed by matrices of ionization chambers, diode detectors, dosimetric films, portal imaging, or dosimetric gels. Another approach is scintillation dosimetry, which has been developed in the last 15 years mainly through scintillating fiber devices. Despite having many advantages over other methods it is still at an experimental level for routine dosimetry because the Cerenkov radiation produced under irradiation represents an important stem effect. A new 2D water equivalent scintillating dosimeter, the DosiMap, and two different Cerenkov discrimination methods were developed with the collaboration of the Laboratoire de Physique Corpusculaire of Caen, the Comprehensive Cancer Center François Baclesse, and the ELDIM Co., in the frame of the MAESTRO European project. The DosiMap consists of a plastic scintillating sheet placed inside a transparent polystyrene phantom. The light distribution produced under irradiation is recorded by a CCD camera. Our first Cerenkov discrimination technique is subtractive. It uses a chessboard pattern placed in front of the scintillator, which provides a background signal containing only Cerenkov light. Our second discrimination technique is colorimetric. It performs a spectral analysis of the light signal, which allows the unfolding of the Cerenkov radiation and the scintillation. Tests were carried out with our DosiMap prototype and the performances of the two discrimination methods were assessed. The comparison of the dose measurements performed with the DosiMap and with dosimetric films for three different irradiation configurations showed discrepancies smaller than 3.5% for a 2 mm spatial resolution. Two innovative discrimination solutions were demonstrated to separate the scintillation from the Cerenkov radiation. It was also shown that the DosiMap, which is water equivalent, fast, and user friendly, is a very promising tool for radiotherapy quality assurance.


Asunto(s)
Radiometría/métodos , Radioterapia de Intensidad Modulada/métodos , Algoritmos , Colorimetría/métodos , Diseño de Equipo , Humanos , Imagenología Tridimensional , Luz , Modelos Estadísticos , Fantasmas de Imagen , Poliestirenos/química , Reproducibilidad de los Resultados
9.
Hum Exp Toxicol ; 27(6): 471-6, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18784199

RESUMEN

The ability of chemicals to produce hearing loss themselves or to promote noise-induced hearing loss has been reported for some organic solvents. The objective of this study was to review the literature on the effects of low-level exposure to n-hexane on the auditory system and consider its relevance for occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the permissible inhalation exposure limits. In Quebec, the time-weighted average exposure value (TWAEV) for 8 h is 50 ppm. In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at five times the TWAEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. There is no convincing evidence of n-hexane-induced hearing loss in workers. In rats, n-hexane seems to affect auditory function; however, the site of these alterations cannot be determined from the present data. Further studies with sufficient data on the exposure of workers to n-hexane are necessary to make a definitive conclusion. In the interim, we recommend considering n-hexane as a possibly ototoxic agent.


Asunto(s)
Adhesivos/efectos adversos , Contaminantes Ocupacionales del Aire/efectos adversos , Pérdida Auditiva/etiología , Hexanos/efectos adversos , Enfermedades Profesionales/etiología , Exposición Profesional/efectos adversos , Animales , Potenciales Evocados Auditivos/efectos de los fármacos , Pérdida Auditiva/fisiopatología , Humanos , Exposición por Inhalación , Ruido/efectos adversos , Enfermedades Profesionales/fisiopatología , Valores Limites del Umbral
10.
Hum Exp Toxicol ; 27(3): 195-200, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18650250

RESUMEN

Organic solvents can cause hearing loss themselves or promote noise-induced hearing loss. The objective of this study was to review the literature on the effects of low-level exposure to trichloroethylene on the auditory system and consider its relevance for the occupational settings. Both human and animal investigations were evaluated only for realistic exposure concentrations based on the Quebec permissible exposure limits: 50 ppm 8-h time-weighed average exposure value (TWAEV) and 200 ppm short-term exposure value (STEV). In humans, the upper limit for considering ototoxicity data relevant to the occupational exposure situation was set at the STEV. Animal data were evaluated only for exposure concentrations up to 100 times the TWAEV. There is no convincing evidence of trichloroethylene-induced hearing losses in workers. In rats, trichloroethylene affects the auditory function mainly in the cochlear mid- to high-frequency range with a lowest observed adverse effect level (LOAEL) of 2000 ppm. No studies on ototoxic interaction after combined exposure to noise and trichloroethylene were identified in humans. In rats, supra-additive interaction was reported. Further studies with sufficient data on the trichloroethylene exposure of workers are necessary to make a definitive conclusion. In the interim, we recommend considering trichloroethylene as an ototoxic agent.


Asunto(s)
Pérdida Auditiva/inducido químicamente , Exposición Profesional/efectos adversos , Tricloroetileno/toxicidad , Animales , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Humanos , Masculino , Ratas , Ratas Endogámicas F344 , Ratas Long-Evans
11.
Radiat Prot Dosimetry ; 131(1): 100-9, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18757897

RESUMEN

New generation of radiation therapy accelerators requires highly accurate dose measurements with high spatial resolution patterns. IMRT is especially demanding since the positioning accuracy of all the multi-leafs should be verified for each applied field and at any incidence. A new 2-D tissue equivalent dosemeter is presented with high spatial resolution that can fulfil these tasks. A plastic scintillator sheet is sandwiched between two polystyrene cubes, and the emitted light is observed by a high-resolution camera. A patented procedure allows efficient discrimination of the scintillation proportional to the dose from the parasitic Cerenkov radiation. This extraction made on the cumulated images taken during an irradiation field at a rate of 10 images s(-1) provides high-resolution mapping of the dose rate and cumulated dose in quasi real time. The dosemeter is tissue equivalent (ICRU-44) and works both for electrons and photons without complex parameter adjustment, since phantom and detector materials are identical. The calibration is simple and independent of the irradiation conditions (energy, fluence, quality and so on). The principle of the dosemeter and its calibration procedure are discussed in this paper. The results and, in particular, the dose depth profiles are compared with standard ionisation chamber measurements in polystyrene for both photons and electrons. Finally, the detector specifications are summarised and one example of complex IMRT field is discussed.


Asunto(s)
Aceleradores de Partículas , Radiometría/instrumentación , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada , Radioterapia , Algoritmos , Calibración , Electrones , Humanos , Fantasmas de Imagen , Fotones , Control de Calidad
12.
Bone Joint J ; 99-B(7): 934-938, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28663400

RESUMEN

AIMS: The aim of the present study was to compare the 30- and 90-day re-admission rates and complication rates of outpatient and inpatient total shoulder arthroplasty (TSA). PATIENTS AND METHODS: The United States Medicare Standard Analytical Files database was questioned to identify patients who had undergone outpatient or inpatient TSA between 2005 and 2012. Patient characteristics were compared between the two groups using chi-squared analysis. Multivariate logistic regression analysis was used to control for differences in baseline patient characteristics and to compare the two groups in terms of post-operative complications within 90 days and re-admission within 30 days and 90 days. RESULTS: A total of 123 347 Medicare subscribers underwent TSA between 2005 and 2012; 3493 (2.8%) had the procedure performed as an outpatient. A significantly greater proportion of patients who underwent TSA as inpatients were women, had a history of smoking, and had a greater incidence of medical comorbidity including diabetes, coronary artery disease, congestive heart failure, and chronic kidney disease (p < 0.05 for all). Re-admission rates were significantly higher for inpatients at both 30 days (0.83% versus 0.60%, p = 0.016, odds ratio 1.8) and 90 days (2.87% versus 2.04%, p < 0.001, odds ratio 1.8). Complications, including thromboembolic events (p < 0.001) and surgical site infection (p = 0.002), were significantly higher in inpatients. CONCLUSION: Patients who underwent TSA on an outpatient basis were overall younger and healthier than those who had inpatient surgery, which suggests that patient selection was taking place. After controlling for age, gender, and medical conditions, patients who underwent TSA as outpatients had lower rates of 30- and 90-day re-admission and a lower rate of complications than inpatients. Cite this article: Bone Joint J 2017;99-B:934-8.


Asunto(s)
Artroplastía de Reemplazo de Hombro , Evaluación de Resultado en la Atención de Salud , Readmisión del Paciente/estadística & datos numéricos , Factores de Edad , Anciano , Anciano de 80 o más Años , Comorbilidad , Femenino , Humanos , Pacientes Internos , Masculino , Medicare , Persona de Mediana Edad , Pacientes Ambulatorios , Complicaciones Posoperatorias/epidemiología , Rango del Movimiento Articular , Factores de Riesgo , Estados Unidos/epidemiología
13.
Med Phys ; 32(9): 3000-6, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16266114

RESUMEN

Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.


Asunto(s)
Aceleradores de Partículas/instrumentación , Radiometría/instrumentación , Conteo por Cintilación/instrumentación , Calibración , Radiación Ionizante , Dosificación Radioterapéutica
14.
Acta Trop ; 42(1): 39-44, 1985 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2859748

RESUMEN

Zinc, copper and magnesium levels were determined by atomic absorption spectrophotometry in the serum of 32 cattle (Zebus and Baoulés) which were proven to be sensitive to African trypanosomiasis under field challenge and 45 cattle (Baoulés and Ndamas/Baoulés) which were proven to be resistant. Copper and magnesium levels were similar in all animals but zinc levels were higher in sensitive animals (1.50 ppm) than in resistant ones (1.10 ppm) (p less than 10(-5)); the reported normal levels of serum zinc is 1.00 ppm. These differences persisted on repeated measurements and whether individuals were infected with trypanosomes or not. Elevated levels of zinc depressed the stimulation of bovine T cells by trypanosomes in vitro and is reported to inhibit antigen presentation by macrophages. Zinc levels may be an influencial factor determining susceptibility or resistance of West African cattle to trypanosomiasis.


Asunto(s)
Tripanosomiasis Bovina/inmunología , Zinc/sangre , Animales , Bovinos , Cobre/sangre , Femenino , Magnesio/sangre , Masculino , Espectrofotometría Atómica , Linfocitos T/inmunología , Tripanosomiasis Africana/sangre , Tripanosomiasis Africana/inmunología , Tripanosomiasis Africana/veterinaria , Tripanosomiasis Bovina/sangre
15.
Acta Trop ; 44(3): 315-23, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2892367

RESUMEN

Nonpermissiveness to trypanosome infection has been correlated in some instances with the presence of toxic serum factors, e.g. high density lipoproteins (HDL) of human serum can lyse T.b. brucei. The present study examines the possibility of a role for such factors in West African cattle that are resistant to trypanosomiasis. Cattle used in this study were previously selected as resistant or sensitive to trypanosomiasis under heavy natural Glossina challenge. - A comparison of the direct effect of serum from trypanoresistant and trypanosensitive Baoulé cattle on the development of pathogenic bloodstream or metacyclic forms of T. congolense, using modifications of the blood infectivity incubation test, failed to demonstrate a difference between these cattle. High density lipoproteins and cholesterol levels were compared in 115 cattle of known sensibility to trypanosomiasis. HDL-cholesterol formed 91% of the total plasma cholesterol. HDL-cholesterol levels in Zebu (mean of 111.8 mg/100 ml) were significantly higher than those in Baoulé cattle (86.2 mg/100 ml). There was no significant difference, however, in these levels between trypanoresistant (73.4 mg/100 ml) and trypanosensitive (84.5 mg/100 ml) Baoulé. Alterations in HDL-cholesterol levels were monitored during an experimental cyclic infection with T. congolense in 5 Zebu and 9 Baoulé. HDL-cholesterol levels decreased in all animals concomitantly with the appearance of trypanosomes in the blood and returned rapidly to their starting values after parasite elimination following drug treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Lipoproteínas HDL/sangre , Tripanosomiasis Bovina/sangre , Animales , Bovinos , Colesterol/sangre , HDL-Colesterol/sangre , Susceptibilidad a Enfermedades , Femenino , Inmunidad Innata , Masculino , Tripanosomiasis Africana/sangre , Tripanosomiasis Africana/inmunología , Tripanosomiasis Africana/veterinaria , Tripanosomiasis Bovina/inmunología , Moscas Tse-Tse
16.
Parassitologia ; 41(1-3): 83-7, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10697837

RESUMEN

There is accumulating evidence of host genetic control in malaria infection and, in humans, some genes have been associated with severe malaria. Nevertheless, other important genes controlling blood infection levels, malarial disease and immune responses are likely to be identified. In this paper, we focus on segregation and linkage analyses of blood infection levels in an urban population living in Burkina Faso. We found evidence of a complex genetic control and a linkage to chromosome 5q31-q33. The identification of genes controlling complex traits related to malaria infection should be helpful in understanding protective mechanisms and the relationship between infection, malaria attacks and severe malaria.


Asunto(s)
Malaria Falciparum/genética , Malaria Falciparum/parasitología , Plasmodium falciparum/genética , Factores de Edad , Animales , Bandeo Cromosómico , Cromosomas Humanos Par 5 , Femenino , Ligamiento Genético , Genotipo , Humanos , Malaria Falciparum/sangre , Masculino , Estaciones del Año
17.
Int J Health Serv ; 20(4): 651-63, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2265881

RESUMEN

This article uses the social constructionist approach to social problems as claims-making activities and Blumer's theory of the developmental stages of social problems to analyze how elder abuse has been constructed as a social problem in Canada and how interest groups have been mobilized to deal with the alleged problem. Clearly, elder abuse has emerged as a social problem (often under the family violence rubric) and has received some legitimation from professional groups and representatives of government. Efforts to mobilize social action against elder abuse at a national level and to develop legislation and other policy initiatives have, however, so far met with mixed success. While elder abuse has been trumpeted by some claims-makers as a major new form of family violence, the absence of a strong elder lobby group and the absence of developed ideologies (e.g., feminism in the case of wife abuse and child sexual abuse) have resulted in elder abuse receiving much less attention than other problems grouped under the family violence rubric. Indeed, most of the legislation that presently exists in Canada deals not with the abuse of the elderly as a class but with the provision of services to dependent, incompetent adults whether they are elderly or not.


Asunto(s)
Abuso de Ancianos , Política Pública , Problemas Sociales , Anciano , Abuso de Ancianos/legislación & jurisprudencia , Humanos , Servicios de Salud Mental , Ontario , Problemas Sociales/legislación & jurisprudencia , Violencia
18.
Sante ; 9(1): 53-9, 1999.
Artículo en Francés | MEDLINE | ID: mdl-10210803

RESUMEN

Genetic factors have clearly been shown to play a role in controlling malarial infection in animal models. There is now also increasing evidence for the genetic control of malaria in man. We carried out a segregation analysis based on blood parasite load phenotype for a population of the town of Bobo-Dioulasso (Burkina-Faso). This analysis demonstrated a strong genetic effect. Our results were not consistent with the segregation of a major gene and thus suggest that parasite load is under the control of minor genes. The genetic effect was stronger in children than in adults. We carried out a regression analysis in children and found that there was an association between the phenotype for blood parasite load and the q31-33 region of chromosome 5. We identified a gene in this region, Pfil1 (Plasmodium falciparum infection levels 1), which accounted for almost 50% of the variance in blood parasite load and which played a fundamental role in the control of infection. The 5q31-33 region contains several genes encoding cytokines that regulate T lymphocytes. The identification of genes controlling malarial infection opens up new possibilities for preventive and treatment strategies. It should be possible in the near future to identify individuals at risk of malaria, who would derive the greatest benefit from preventive and therapeutic measures. Finally, a deeper understanding of these genes controlling protective immune responses could be of value for the development of vaccines.


Asunto(s)
Malaria Falciparum/genética , Adolescente , Adulto , Factores de Edad , Animales , Burkina Faso/epidemiología , Niño , Preescolar , Mapeo Cromosómico , Cromosomas Humanos Par 5/genética , Femenino , Humanos , Lactante , Recién Nacido , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Masculino , Fenotipo , Análisis de Regresión
19.
Iran J Public Health ; 41(5): 13-30, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23113174

RESUMEN

Because many diseases are multifactorial disorders, the scientific progress in genomics and genetics should be taken into consideration in public health research. In this context, genomic databases will constitute an important source of information. Consequently, it is important to identify and characterize the State's role and authority on matters related to public health, in order to verify whether it has access to such databases while engaging in public health genomic research. We first consider the evolution of the concept of public health, as well as its core functions, using a comparative approach (e.g. WHO, PAHO, CDC and the Canadian province of Quebec). Following an analysis of relevant Quebec legislation, the precautionary principle is examined as a possible avenue to justify State access to and use of genomic databases for research purposes. Finally, we consider the Influenza pandemic plans developed by WHO, Canada, and Quebec, as examples of key tools framing public health decision-making process. We observed that State powers in public health, are not, in Quebec, well adapted to the expansion of genomics research. We propose that the scope of the concept of research in public health should be clear and include the following characteristics: a commitment to the health and well-being of the population and to their determinants; the inclusion of both applied research and basic research; and, an appropriate model of governance (authorization, follow-up, consent, etc.). We also suggest that the strategic approach version of the precautionary principle could guide collective choices in these matters.

20.
Public Health Genomics ; 13(4): 224-34, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20395691

RESUMEN

Genetic information can be used to target interventions that improve health and prevent disease. Indeed, the results of population genomics research could be useful for public health and national pandemic plans. Yet, firm scientific evidence originating from such research and the indicators of the role of health determinants, gene-gene and gene-environment interaction remain to be assessed and validated before being integrated into pandemic plans or public health programmes. It is not clear what is the role of the State in research on the elucidation of the determinants of gene-gene and gene-environment interactions and how, when, and if such data can be accessed and used for such planning. Over a period of 3 years, we sought to address these questions by gathering data and literature relevant to research in public health genomics, preparing issues papers and, finally, consulting with stakeholders on a provisional 'points to consider' document at various times. Examining in turn the issues of privacy, State powers, stakeholder perceptions, and public participation, we propose in this article, for each of these themes, a series of recommendations aiming to provide guidance on the role of the State in the use of genomic information for public health research, prevention and planning.


Asunto(s)
Genómica/ética , Genómica/tendencias , Política de Salud , Salud Pública , Bioética , Canadá , Bases de Datos Genéticas , Planificación en Salud/métodos , Promoción de la Salud/métodos , Humanos , Participación del Paciente , Percepción , Quebec , Regionalización
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