RESUMEN
Drug delivery via the hair follicle (HF) especially with nanoparticles (NP) recently gained attention due to a depot effect and facilitated absorption conditions within the lower HF. With the prospect of transdermal drug delivery, it is of interest to optimize the follicular uptake of NP. In this study, a method was developed to quantify NP uptake into HF and applied in vitro in a pig ear model and in vivo in human volunteers. The influence of NP material on HF uptake was investigated using fluorescence-labeled NP based on poly(D,L-lactide-co-glycolide) (PLGA). All NP had similar hydrodynamic sizes (163-170 nm) but different surface modifications: (i) plain PLGA, (ii) chitosan-coated PLGA (Chit.-PLGA), and (iii) Chit.-PLGA coated with different phospholipids (PL) (DPPC (100), DPPC:Chol (85:15), and DPPC:DOTAP (92:8). Differential stripping was performed, including complete mass balance. The samples were extracted for fluorescence quantification. An effect of the PL coating on follicular uptake was observed as DPPC (100) and DPPC:DOTAP (92:8) penetrated into HF to a higher extent than the other tested NP. The effect was observed both in the pig ear model as well as in human volunteers, although it was statistically significant only in the in vitro model. An excellent in vitro-in vivo correlation (IVIVC, r(2)=0.987) between both models was demonstrated, further supporting the suitability of the pig ear model as a surrogate for the in vivo situation in humans for quantifying NP uptake into HF. These findings may help to optimize NP for targeting the HF and to improve transdermal delivery.
Asunto(s)
Portadores de Fármacos , Folículo Piloso/metabolismo , Ácido Láctico/metabolismo , Nanopartículas , Ácido Poliglicólico/metabolismo , Absorción Cutánea , Administración Cutánea , Animales , Quitosano/metabolismo , Oído , Femenino , Colorantes Fluorescentes/metabolismo , Antebrazo , Humanos , Ácido Láctico/administración & dosificación , Ácido Láctico/química , Masculino , Tamaño de la Partícula , Fosfolípidos/metabolismo , Ácido Poliglicólico/administración & dosificación , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Propiedades de Superficie , PorcinosRESUMEN
BACKGROUND: Successful clinical development of novel cellular therapeutics requires the evaluation of clinical acute toxicity endpoints in scoring patient adverse events (AE) contributing to dose-limiting toxicity (DLT) for establishment of the maximum-tolerated dose (MTD). However, many clinical pathology parameters are not routinely evaluated in pre-clinical safety testing. The objective of this pre-clinical study was to investigate thoroughly the acute toxicity of single- and multiple-dose administrations of allogeneic multipotent adult progenitor cells (MultiStem), which represent a class of stromal stem cells with therapeutic potential. METHODS: MultiStem were tested as an adjunct treatment in a rat myeloablative hematopoietic stem cell transplantation (HSCT) model for impact on clinical parameters, clinical chemistry, hematology, immunology and histopathology parameters. Animals received MultiStem in a single dose of 12.5 million cells/kg on day 2 after HSCT or in five infusions at this dose on days 2, 9, 16, 23 and 30. Controls received phosphate-buffered saline injections and all animals were killed on day 37. RESULTS: There were no significant differences between tests and controls regarding evaluation of respiratory distress upon infusion, clinical assessment and hematology and clinical chemistry analysis. Gross necropsy and histopathology analysis showed no organ profile alterations. There was no significant evidence for allogeneic antibody production or T-cell sensitization upon MultiStem infusion. DISCUSSION: These studies demonstrate the safety of administration of allogeneic stromal stem cells in repeat dosing regimens in bone marrow transplant settings, and define pre-clinical safety testing standards relevant to the development of cellular therapeutics using allogeneic adherent adult stem cells.
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Células Madre Adultas/inmunología , Células Madre Adultas/metabolismo , Células Madre Adultas/trasplante , Trasplante de Médula Ósea/inmunología , Células Madre Multipotentes/trasplante , Animales , Trasplante de Médula Ósea/efectos adversos , Modelos Animales de Enfermedad , Células Madre Multipotentes/inmunología , Ratas , Ratas Endogámicas BUF , Trasplante Homólogo/efectos adversos , Trasplante Homólogo/inmunologíaRESUMEN
Fundamento: Se presenta una revisión sistemática con metaanálisis de los efectos del uso de risedronato y raloxifeno en las fracturas y en la densidad mineral ósea (DMO), de cadera, vértebra y muñeca en las mujeres con osteoporosis posmenopáusica. Material y método: Se revisaron los ensayos clínicos publicados desde 1966 hasta septiembre de 2002 en MEDLINE, Cochrane Library, EMBASE, Pascal Biomed y publicaciones de la Sociedad Española de Reumatología, Sociedad Española de la Investigación Ósea y del Metabolismo Mineral y Fundación Hispana de Osteoporosis y Enfermedades Metabólicas Óseas. Resultados y discusión: Se incluyeron 8 ensayos clínicos con risedronato y 6 con raloxifeno. A las dosis recomendadas (5 mg de risedronato y 60 mg de raloxifeno) con seguimiento de 2 o más años, el riesgo relativo (RR) de fracturas de cadera fue de 0,74 (intervalo de confianza [IC] del 95 por ciento, 0,59-0,94) y 1,13 (IC del 95 por ciento, 0,66-1,96) con risedronato y raloxifeno, respectivamente; en fracturas vertebrales fue de 0,61 (IC del 95, por ciento 0,50-0,75) y 0,65 (IC del 95 por ciento, 0,53-0,79), respectivamente, y en fracturas de muñeca de 0,67 (IC del 95 por ciento, 0,42-1,07) y 0,88 (IC del 95 por ciento, 0,67-1,14), respectivamente. El incremento de la DMO para risedronato y raloxifeno vertebral fue del 4,32 por ciento (IC del 95 por ciento, 3,78-4,88) y del 2,62 por ciento (IC del 95 por ciento, 2,40-2,82); femoral del 2,77 por ciento (IC del 95 por ciento, 2,37-3,17) y 1,39 por ciento (IC del 95 por ciento, 1,03-1,75), y en el trocánter del 3,94 por ciento (IC del 95 por ciento, 3,29-4,58) y 1,72 por ciento (IC del 95 por ciento, 0,602,85), respectivamente. Risedronato disminuyó el riesgo de fractura en cadera, no así en muñeca, mientras raloxifeno no mostró un efecto reductor de fracturas ni en cadera ni en muñeca. La reducción del riesgo de fractura vertebral se produjo en ambos fármacos. En trocánter, fémur y vértebra, ambos fármacos produjeron aumentos en la DMO (AU)
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Adulto , Femenino , Persona de Mediana Edad , Humanos , Fracturas de Cadera/diagnóstico , Fracturas de Cadera/prevención & control , Fracturas de Cadera/terapia , Traumatismos de la Muñeca/diagnóstico , Traumatismos de la Muñeca/patología , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/diagnóstico , Osteoporosis/complicaciones , Osteoporosis/diagnóstico , Osteoporosis/tratamiento farmacológico , Antirreumáticos/uso terapéutico , Traumatismos Vertebrales/diagnóstico , Clorhidrato de Raloxifeno/uso terapéutico , Selección de Paciente , Densidad Ósea/fisiología , Densidad Ósea , Fracturas de Cadera/diagnóstico , Fracturas de Cadera/tratamiento farmacológico , Sistemas de Información/estadística & datos numéricos , Sistemas de Información , Fracturas Óseas/epidemiologíaRESUMEN
BACKGROUND: The aim of this study was to investigate necessity and outcome of late pulmonary valve replacement (PVR) after repair of tetralogy of Fallot (TOF). METHODS: Hospital records from patients operated on for TOF at our institution between 1960 and 2002 were reviewed and patients were interviewed by questionnaires. RESULTS: Out of 411 long-term survivors after TOF-repair, 47 (11.4 %) patients required reoperation after 13.2 +/- 7.4 years. Preoperative right ventricular (RV) dilatation was present in 36 (76.6 %) patients including 16 (34 %) with impaired RV function. Isolated PVR was performed in 12 patients (25.5 %). Additional procedures were necessary in 35 patients (74.5 %), including closure of residual defects (VSD, n = 11), tricuspid valve replacement (n = 1) and repair (n = 3). Obstructive right ventricular or pulmonary artery lesions (34 patients, 72.3 %) were all surgically addressed. RV pressure decreased from 61.1 +/- 27.7 to 42.9 +/- 13.3 mm Hg (p < 0.01) after PVR. RV size was reduced and RV function improved compared to preoperative values. Early mortality after reoperation was 2.1 % (n = 1) with one patient dying from biventricular failure. There was no late mortality. CONCLUSIONS: PVR after Fallot repair is frequently required because of progressive RV enlargement with dysfunction. It can be performed with relatively low risk, even in the setting of multiple reoperation. Obstructive lesions (RVOTO, PA stenosis) and residual defects are frequently observed in patients needing late PVR and may play a crucial role in the development of RV failure. Timely valve replacement with repair of all obstructive lesions proximal and distal to the implanted valve is the key to preserving RV function.
Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas , Válvula Pulmonar/cirugía , Reoperación , Tetralogía de Fallot/cirugía , Adolescente , Adulto , Niño , Preescolar , Tolerancia al Ejercicio/fisiología , Estudios de Seguimiento , Alemania , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/cirugía , Humanos , Lactante , Tiempo de Internación , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/cirugía , Válvula Pulmonar/patología , Insuficiencia de la Válvula Pulmonar/fisiopatología , Insuficiencia de la Válvula Pulmonar/cirugía , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Volumen Sistólico/fisiología , Factores de Tiempo , Resultado del Tratamiento , Insuficiencia de la Válvula Tricúspide/fisiopatología , Insuficiencia de la Válvula Tricúspide/cirugía , Presión Ventricular/fisiologíaRESUMEN
Although some research attention has been given to the factors associated with temptation and lapse in dieting, the majority of research has focused on individuals in weight loss clinical trials and relied heavily on retrospective self-report data. The present study sought to overcome these limitations by using ecological momentary assessment (EMA) techniques to examine situations of dietary temptation, lapse, and minimal dietary consequence with a sample of overweight dieters (N=30) attempting to lose weight on their own. Results support and extend previous research findings on dietary temptation and lapse. In general, results indicate that recent consumptive activity, location, mood state, type of activity, and abstinence violation effects were related to moments of temptation and/or lapse. Education on the factors associated with dietary temptation and lapse and strategies for addressing these factors is imperative for both dieters in formal programs and those attempting to lose or maintain weight on their own.
RESUMEN
The physical nature of the agent that causes transmissible spongiform encephalopathies (the 'prion'), is the subject of passionate controversy. Investigation of it has benefited tremendously from the use of transgenic and knockout technologies. However, prion diseases present several other enigmas, including the mechanism of brain damage and how the affinity of the agent for the central nervous system is controlled. Here we show that such questions can be effectively addressed in transgenic and knockout systems, and that pathogenesis may be clarified even before we can be certain about the nature of the infectious agent. Availability of mice overexpressing the Prnp gene (which encodes the normal prion protein) and Prnp knockout mice allows for selective reconstitution experiments aimed at expressing PrP in specific portions of the brain or in selected populations of hemato- and lymphopoietic origin. We summarize how such studies can offer insights into how prions administered to peripheral sites can gain access to central nervous tissue, and into the molecular requirements for spongiform brain damage.
Asunto(s)
Enfermedades por Prión/metabolismo , Priones/metabolismo , Animales , Barrera Hematoencefálica , Encéfalo/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Neuronas/trasplanteRESUMEN
OBJECTIVE: To evaluate the efficacy and tolerability of aceclofenac, a new nonsteroidal antiinflammatory drug, in patients with active ankylosing spondylitis (AS). METHODS: 310 outpatients with active AS were enrolled in a 3 month, multicenter, parallel, double blind trial and were randomly assigned to receive aceclofenac (200 mg daily) or indomethacin (100 mg daily). They were evaluated after a washout period of 7 days, at baseline, 15, 30, 60, and 90 days. RESULTS: No significant differences were found between aceclofenac and indomethacin in the number of withdrawals due to lack of efficacy or adverse events. A repeated measures analysis (ANOVA) of patients who completed the trial showed no significant differences between either treatment. Within-group comparisons in an intention-to-treat analysis showed improvement (p < 0.05) in all the primary efficacy variables: pain visual analog scale (VAS) (37 vs 41%), morning stiffness (51 vs 46%), modified Schober's test (21 vs 16%), C7-iliac crest line distraction (11 vs 14%), lateral spinal flexion (6 vs 10%), in aceclofenac and indomethacin treated patients, respectively. Other variables including chest expansion, occiput-to-wall, Likert pain score, use of analgesic rescue, and patient and physician global assessment, also showed significant improvement from baseline values. No significant differences between treatments were noted for any efficacy variable. Good to excellent improvement in pain (52 vs 64%) and morning stiffness (70 vs 68%) was observed in aceclofenac and indomethacin treated patients, respectively. Patients taking aceclofenac had significantly fewer central nervous system related adverse events than patients treated with indomethacin (p < 0.001). CONCLUSION: Aceclofenac and indomethacin did not differ with respect to efficacy in the treatment of active AS, although aceclofenac was slightly better tolerated.
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Antiinflamatorios no Esteroideos/administración & dosificación , Diclofenaco/análogos & derivados , Espondilitis Anquilosante/tratamiento farmacológico , Adulto , Antiinflamatorios no Esteroideos/efectos adversos , Diclofenaco/administración & dosificación , Diclofenaco/efectos adversos , Método Doble Ciego , Femenino , Humanos , Indometacina/administración & dosificación , Indometacina/efectos adversos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Cooperación del Paciente , Participación del Paciente , Factores de TiempoRESUMEN
The efficacy and tolerability of aceclofenac (100 mg bid; n = 109), a new non-steroidal anti-inflammatory agent, was compared to that of indomethacin (50 mg bid; n = 110) in a multi-centre, 12-week, randomized, double-blind clinical trial in patients with rheumatoid arthritis. The efficacy of aceclofenac, on the basis of several clinical features characteristic for rheumatoid arthritis, was comparable to that of indomethacin. Patients in both treatment groups showed a notable and significant improvement during the study. Under aceclofenac treatment, the number of painful and swollen joints decreased by a median of six and nine, respectively, morning stiffness was shortened by 1 h, and the grip strength of both hands increased by a median of 8 mmHg. Pain at rest was relieved in 65.3% of aceclofenac-treated patients and in 67.1% of those treated with indomethacin (n.s.). With regard to safety, aceclofenac tended to be better tolerated than indomethacin. Among the 109 aceclofenac-treated patients, 26 incidents of adverse effects due to the drug were noted in 20 patients (18.4%). Sixty-four incidents of adverse events were documented in 32 (29.1%) of the 110 patients treated with indomethacin. The most common adverse events reported during treatment with aceclofenac were heartburn (four patients) and vertigo (three patients).
Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Diclofenaco/análogos & derivados , Indometacina/uso terapéutico , Alanina Transaminasa/sangre , Antiinflamatorios no Esteroideos/efectos adversos , Diclofenaco/efectos adversos , Diclofenaco/uso terapéutico , Elasticidad/efectos de los fármacos , Femenino , Fuerza de la Mano , Pirosis/inducido químicamente , Humanos , Indometacina/efectos adversos , Articulaciones/efectos de los fármacos , Masculino , Persona de Mediana Edad , Dimensión del Dolor/efectos de los fármacos , Estadísticas no Paramétricas , Resultado del Tratamiento , Vértigo/inducido químicamenteRESUMEN
From compulsory screening examinations of 260,917 noise-exposed workers standardized audiograms as well as medical and occupational histories of 110,647 workers were selected because of full-time exposure to well-defined noise greater than 85 dB (A) and analyzed by loglinear and multiple linear regression. The most important factors for prediction of pure-tone hearing loss at 4 kHz were found to be age, sex and noise immission level. For predicting speech impairment and handicap the history of ear disease, head injury and tinnitus were more important than noise immission level. Dose-response relationships are given to improve prevention and compensation of hearing loss from combined factors.
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Traumatismos Craneocerebrales/diagnóstico , Enfermedades del Oído/diagnóstico , Trastornos de la Audición/diagnóstico , Pérdida Auditiva Provocada por Ruido/diagnóstico , Ruido en el Ambiente de Trabajo/efectos adversos , Adolescente , Adulto , Factores de Edad , Anciano , Audiometría de Tonos Puros , Traumatismos Craneocerebrales/complicaciones , Traumatismos Craneocerebrales/epidemiología , Enfermedades del Oído/epidemiología , Enfermedades del Oído/fisiopatología , Femenino , Estudios de Seguimiento , Cefalea/epidemiología , Cefalea/etiología , Trastornos de la Audición/epidemiología , Pérdida Auditiva Provocada por Ruido/epidemiología , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Acúfeno/epidemiología , Acúfeno/etiologíaRESUMEN
The hearing loss of 46,776 subjects exposed to hazardous impact or continuous noise was measured: 11% were exposed to impact noise (10.3% in men, 12.7% in women). Impact noise causes less hearing loss than continuous noise up to a noise emission level (NIL) of 115 dB(A). This result is still compatible with the concept of equivalent continuous A-weighted sound pressure level (LA,eq) and seems to be caused by the protective effect of the stapedius muscle. However, at emission levels higher than 115 dB(A), not covered by ISO 1999 prognosis, impact noise becomes more detrimental. This could be the effect of mechanical damage to the organ of Corti, as observed in animal experiments at sound pressure levels exceeding 114 dB(A). A diminishing protective function of the stapedius muscle could explain the more serious hearing impairment after long exposure to impact noise compared with shorter exposures to an equal dose. Since the hearing loss caused by impact or continuous noise is clearly different in the highest NIL ranges, safety criteria for impact noise should be revised. The NIL defined by Burns and Robinson underestimates the effect of the exposure time for impact noise.
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Pérdida Auditiva Provocada por Ruido/prevención & control , Pruebas Auditivas , Tamizaje Masivo , Enfermedades Profesionales/prevención & control , Exposición Profesional , Adolescente , Adulto , Anciano , Audiometría de Tonos Puros , Umbral Auditivo , Femenino , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/etiología , Factores de RiesgoRESUMEN
Weighted regression analysis was applied to determine the dependence of the hearing thresholds of 47,388 noise-exposed workers on age, sex, noise immission level, ear disease, head injury, tinnitus, hearing protector usage, and audiometric frequency in the range from 0.5 to 6 kHz. It could be shown that the hearing thresholds at any frequency are dominated by the age of the worker and that women, after equivalent exposure conditions, hear better than men. The relative effects of sex, noise immission level, ear diseases, tinnitus, and hearing protector usage are related to the audiometric frequency. Users of hearing protectors at the last audiometric investigation hear worse than nonusers. Hearing protector usage is strongly related with the hearing threshold in the low-frequency range. The noise immission level does not noticeably affect the hearing threshold below 3 kHz. The most important frequency of the noise immission level is as expected 4 kHz. For 4 kHz, it was shown that the variables age, noise immission level, tinnitus, head injuries, and ear diseases act in a good approximation additively on the pure-tone hearing threshold.
Asunto(s)
Pérdida Auditiva Provocada por Ruido/epidemiología , Enfermedades Profesionales/epidemiología , Adolescente , Adulto , Factores de Edad , Audiometría de Tonos Puros , Umbral Auditivo , Traumatismos Craneocerebrales/complicaciones , Enfermedades del Oído/complicaciones , Dispositivos de Protección de los Oídos , Femenino , Pérdida Auditiva Provocada por Ruido/diagnóstico , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Ruido en el Ambiente de Trabajo/efectos adversos , Enfermedades Profesionales/diagnóstico , Enfermedades Profesionales/etiología , Factores de Riesgo , Acúfeno/complicacionesRESUMEN
Practical examples from preventive and curative medicine are given to demonstrate how competing selection rates distort the results of epidemiological studies. In order to quantify this distorsion the bias is tabulated and graphed for different combinations of features (diseases, symptoms, findings, etc.) on the one hand and different admission or participation rates on the other hand. With the help of a formula which can be stored in a pocket calculator the sample bias can be quantified also. Prerequisite is the estimation of selection rates. They have such a bearing on the results of epidemiological studies that it is advisable to ask two questions before any interpretation: 1. which factors can lead to different admission rates in the groups (A,B) under study and 2. which factors can lead to different admission rates of persons with and without the feature (X) under study.
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Métodos Epidemiológicos , Asbestosis , Enfermedad Coronaria , Femenino , Indicadores de Salud , Encuestas Epidemiológicas , Humanos , Neoplasias Pulmonares , Masculino , Tamizaje Masivo , Modelos Teóricos , Enfermedades Profesionales , RiesgoAsunto(s)
Pérdida Auditiva Provocada por Ruido/diagnóstico , Enfermedades Profesionales/diagnóstico , Discriminación de la Altura Tonal , Adulto , Audiometría de Tonos Puros , Fatiga Auditiva , Conmoción Encefálica/complicaciones , Daño Encefálico Crónico/complicaciones , Diagnóstico Diferencial , Testimonio de Experto , Humanos , Persona de Mediana Edad , Ruido en el Ambiente de Trabajo/efectos adversosRESUMEN
63 workers of a chromium manufacturing plant were investigated: 47 workers suffered from an obstructive bronchitis, 32 from an illness of the upper respiratory tract. In some workers acetylcholine provocation was positive. No correlation was found between blood chromium levels and clinical findings.
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Bronquitis/etiología , Cromo/efectos adversos , Adulto , Resistencia de las Vías Respiratorias , Cromo/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/etiología , Enfermedades Profesionales/etiología , FumarRESUMEN
The application of a polychotomous generalization of the linear probabilistic model of Cox is described, which allows the investigation of the effects of different noise levels with various durations of exposure on hearing. If the model assumptions are not rejected, it is possible to separate the effect of noise exposure from the effect of age. The results will thus show to what extent the hearing losses of an industrial worker are due to presbyacusis or to noise exposure. An empirical investigation was based on the evaluation of hearing losses at the audiometric frequencies 1, 2 and 3 kHz in 35 212 industrial workers of both sexes. It was attempted to predict the distribution of hearing losses in the left and the right ear as an additive function of the effect of noise exposure, age and sex. The parameters describing the effect of age increased linearly. Noise levels equal to and above 85 dB(A) have a noxious influence on hearing. Furthermore, hearing loss does not increase continuously with duration of exposure; from 15 years onwards, no essential increase in hearing loss appears which can be attributed to noise at work.
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Pérdida Auditiva Provocada por Ruido/epidemiología , Enfermedades Profesionales/epidemiología , Adolescente , Adulto , Factores de Edad , Exposición a Riesgos Ambientales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Ruido en el Ambiente de Trabajo , Presbiacusia/epidemiología , Factores Sexuales , Estadística como Asunto , Factores de TiempoRESUMEN
The case material comprising all persons who developed silico-tuberculosis since it was listed as an occupational disease almost 50 years ago is analysed. The relationship between various occupations and the incidence of silicosis is reviewed with special reference to the most exposed group: the wokers in the granite quarries of Upper Austria. The changes in the clinical picture of the lesion, legal aspects, diagnostic difficulties in distinguishing between silicosis with or without complicating tuberculosis are discussed.
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Silicotuberculosis/epidemiología , Adulto , Austria , Diagnóstico Diferencial , Humanos , Persona de Mediana Edad , Enfermedades Profesionales , Silicosis/diagnóstico , Silicotuberculosis/diagnóstico , Indemnización para TrabajadoresRESUMEN
In an agricultural town in Burgenland (Austria) we found an increased prevalence of pleural plaques. These calcifying thickenings of the pleura are related to minimal asbestos exposure such as is mesothelioma, but they cannot be regarded as a precancerosis. The increased occurrence of pleural plaques in this town of nearly 3500 inhabitants (in which during 1916 to 1945 asbestos was mined) we first found at the chest x-ray archives of a pulmologic hospital, then by mass radiography and blind comparison with control groups. A photofluoroscopy of 300 persons yielded 16 cases with definite pleural plaques (5.3%) among which were 4 cases with suspected asbestosis and another 14 cases with uncertain pleural plaques (4.7%). The 600 control persons showed no such radiological changes. Interviews wich persons detected for pleural plaques at mass radiography gave no indication that they had occupational asbestos exposure. But asbestos was detected in the soil of vineyards and in the dust of the houses. Asbestos was also detectable in the atmospheric dust by x-ray diffraction and scanning electron microscopic techniques.