Biomedical subjects

H J Miller

Publications and source records attributed to H J Miller.

34 records · Page 2Linked to original sources

PubMed1978

Polychlorinated biphenyls induced rat liver adenomas.

Multiple liver adenomas were found in 30 month old female rats which had received for 28 months, 200 ppm polychlorinated biphenyls (Arochlor 1254) in their drinking water. No lung metastases were detected. The examination of fragments of these adenomas under the electron microscope showed group polymorphism of the hyperplastic liver cells. The ultrastructural changes were considered to be as a result of chemical lesions induced by polychlorinated biphenyls and as adaptive morphological responses to the long term exposure to toxic chemical compounds. The group polymorphism was seen in the light of the clonal theory, to be the result of inherited biochemical lesions occurring in cells of hyperplastic liver nodules.

Adenoma↗

PubMed1978

The effects of unsatisfactory working conditions on the epidemiology of unauthorised absenteeism in an old textile factory in Isfahan, Iran.

Comparison of unauthorised absenteeism rates were made between two large textile factories in Isfahan, Iran. The working conditions in the study factory were rather unsatisfactory, unlike the control factory. Comparison showed significantly higher rates for the study factory: the average annual duration per person was 7 days in the study factory versus 2.5 days in the control factory, and lost time percentage was 2.4% in the former versus 0.84% in the control. Inception rate of persons was 0.73 versus 0.48, and point prevalence rates 0.002 versus 0.001, whilst period prevalence rates were 0.016 versus 0.011 for the study and control factories respectively. Examination of the study factory data was made to determine any possible relationship between unauthorised absenteeism rates and age and length of employment. It was found that higher unauthorised rates were found amongst the younger workers, 100% for those age 19 and under, versus 59.6% for those age 50 and over. 9.16% of workers employed for 1--4 years took such leave against 70.14% of those employed for 10 or more years. Only 18.8% of all workers took certified sickness absenteeism and the rate increased with age. It was suggested that worker dissatisfaction toward unsatisfactory working conditions may be expressed in terms of unauthorised absenteeism. In view of the widespread consequences of such absenteeism, it is recommonded that closer attention be paid to improve the quality of working life.

Absenteeism↗

PubMed1977

Analysis of foods for arsenic and selenium by acid digestion, hydride evolution atomic absorption spectrophotometry.

A method based on acid digestion, hydride evolution atomic absorption spectrophotometry for estimating microgram and submicrogram quantities of As and Se in foods was developed and evaluated. Samples up to 3 g dry weight were digested with HNO3-HCIO4-H2SO4. As and Se in aliquots of the digests were reduced with NaBH4 to volatile hydrides, using laboratory-constructed and commercially available generators. As and Se were estimated by transient signal atomic absorbance measurements as the hydrides were decomposed in an Ar-H2-entrained air flame. Recoveries of inorganic As and Se added at levels of 0.1-1.0 microgram/g to a variety of foods ranged from 70 to 125%. Analyses of several standard reference samples indicated the method is capable of recovering native analytes. Detection limits for the determinative step and the method as a whole were as low as 5 and 25 ng, respectively, for both elements.

Arsenic↗

PubMed1977

Acid digestion, hydride evolution atomic absorption spectrophotometric method for determining arsenic and selenium in foods: collaborative study. tpart I.

The hydride evolution atomic absorption spectrophotometric (AAS) method for determining As and Se in foods developed and evaluated by the Food and Drug Administration and Agriculture Canada laboratories was subjected to collaborative study, Twenty-four laboratories provided results for As and 23 provided results for Se levels in 13 different samples consisting of tuna, swordfish, flounder, oyster, liver, flour, skim milk poweder, spinach, kale, and apple containing natural levels of As and Se in the ranges 0-15,000 and 0-4000 ng/g, respectively. Reference materials formed a substantial segment of samples, and a number of other laboratories using fluorometry, colorimetry, neutron activation, spark source mass spectrometry, and graphite furnace AAS provided confirmative reference values for the remaining samples. A variety of hydride generation instruments were used, ranging from commercially available devices to semiautomated and fully automated custom-made instruments. Although the accuracy of the method was fairly good, between-laboratory and between-determination (hydride evolution AAS measurement) precisions were not favorable. The main advantage of the hydride AAS method is the rapidity of the determinative step.

Arsenic↗

PubMed1975