RESUMEN
Two affected individuals of the Swedish family with CDA, type III, in which the disease is transmitted as an autosomal dominant character, were studied. Both cases displayed features hitherto undescribed in this family but described in patients with CDA, type III, in whom the inheritance may have been as an autosomal recessive character. Such features were: (a) haemosiderinuria, (b) grossly disorganised erythroblast nuclei, (c) differences in the ultrastructural appearances of individual nuclei within the same multinucleate erythroblast and (d) intraerythroblastic inclusions resembling precipitated globin chains. In both cases the giant mononucleate erythroblasts and the multinucleate erythroblasts had total DNA contents up to 28c (1c = haploid DNA content) and 48c respectively, and some DNA synthesising bi- and multinucleate erythroblasts contained one or more nuclei which were unlabelled with 3H-thymidine. These findings are similar to those in patients with the autosomal recessive type of disease. Thus no major phenotypic differences are yet apparent between cases of CDA, type III, with different patterns of inheritance. Analysis of the surface erythrocyte proteins of the 2 Swedish CDA, type III, patients with monoclonal antibodies recognising Band 3, glycophorins A, B, C and D, Rh, CD44, CD47, CD55, CD58, CD59, Lutheran, Kell, LW and acetylcholinesterase did not reveal any gross abnormality of expression of these proteins. A slightly altered expression of blood group antigens A and H was revealed by the lectins Dolichos biflorus and Ulex europaeus and the Mr of Band 3 as judged by SDS polyacrylamide gel electrophoresis was also slightly reduced, suggesting that there may be minor alterations in the degree of N-glycosylation of some red cell membrane constituents.
Asunto(s)
Anemia Diseritropoyética Congénita/patología , Sistema del Grupo Sanguíneo ABO , Adulto , Anciano , Anemia Diseritropoyética Congénita/sangre , Proteínas Sanguíneas/análisis , Médula Ósea/patología , Núcleo Celular/patología , Citoplasma/patología , ADN/metabolismo , Eritroblastos/metabolismo , Eritroblastos/ultraestructura , Membrana Eritrocítica/química , Membrana Eritrocítica/inmunología , Femenino , Fase G1 , Fase G2 , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/ultraestructura , Humanos , Immunoblotting , Masculino , Microscopía Electrónica , SueciaRESUMEN
An accidental discharge of a total flooding Halon 1301 fire extinguishing system is described. The release of the Halon was accompanied by a sudden very loud noise, considerable air turbulence and a dense fog, resulting in worker anxiety and loss of visibility. The workers in the area at the time of the discharge reported higher frequencies of lightheadedness, headache, nasal complaints and disorientation than those entering the area later. Halon 1301 usually is regarded as having a low toxicity, although at concentrations above those used in occupied spaces, effects on consciousness and cardiac rhythm have been reported. In the present report no significant illness or injury due to the Halon exposure was found. A fine oily deposit found on horizontal surfaces in the area subsequent to the discharge consisted of mineral oil and iron, suggesting that this material was scoured out of the piping as the Halon discharged. The disorientation and anxiety produced by an accidental discharge can be minimized through education programs designed to ensure that personnel know what to expect and how to abort the discharge if it results from a false alarm. Situations leading to triggering of fire detectors by events other than fires should be investigated and reduced.
Asunto(s)
Accidentes de Trabajo , Clorofluorocarburos de Metano/envenenamiento , Sistemas de Extinción de Incendios , Incendios , Ansiedad , Bromoclorofluorocarbonos , Humanos , Ruido , Enfermedades Profesionales/inducido químicamente , Enfermedades Profesionales/psicologíaRESUMEN
Blood lead concentration and red cell delta-aminolevulinic acid dehydrase (ALAD) activity were determined at intervals for eight months after symptom-free dogs, which had received 100 ppm or 500-1000 ppm of lead, by weight, in their diets for 75 1/2 weeks, were returned to a lead-free diet. Statistical treatment of the data disclosed a linear relationship between the logarithm of blood lead concentration or of ALAD activity and the logarithm of time (experimental week) during the recovery period. The calculated regressions predict that recovery of ALAD will occur before recovery of the blood lead concentration. Predicted recovery times depend on the levels selected as those which must be attained for recovery to be complete, as well as on the dosage of lead. The logarithm of the slope of the ALAD recovery regression of the individual dog has a linear relation to the percentage reduction in ALAD due to the lead, the regression accounting for 92% of the variance in the recovery rates. The slope of the blood lead recovery regression has a linear relation to the increase in blood lead for the dogs which received the low lead diet, but not for those which received the high lead diet.