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Biomedical subjects

A Miller

Publications and source records attributed to A Miller.

At least 721 records · Page 40Linked to original sources
PubMed1975

Screening tests for pulmonary function abnormality.

Simple tests based on a voluntary forced expiration can detect pulmonary impairment of occupational or environmental origin earlier than can be done using clinical or radiographic examination. These tests are easily performed and repeated, require little time and can be readily set up in the field. Flow impairment ("obstructive") has conventionally been measured by the forced expiratory volume--1 sec (FEV1); earlier changes, in the small airways are more likely to be detected by the maximal mid-expiratory flow (MMF) and the maximum expiratory flow-volume (MEFV) curve at low lung volumes. Volume impairment ("restrictive") is detected by the forced vital capacity (FVC) from which the preceding measurements are made.

Airway Obstruction↗
PubMed1975

Pulmonary function defects in nonsmoking vinyl chloride workers.

Pulmonary function was assessed by spirometry and maximum expiratory flow-volume curves to determine whether exposure to an occupational environment contaminated with vinyl chloride (VC) fumes and poly(vinyl chloride) (PVC) dust is associated with an increased risk of respiratory impairment. Data were analyzed for smoking, duration of exposure, and age. The high prevalence of impaired flow (57.5%) could not be attributed to smoking. Prevalence in nonsmokers was 36.4% when exposure was less than 10 yr, 42% when exposure was between 10 and 20 yr, and 80% when exposure exceeded 20 yr. The last is virtually the same rate as for smokers exposed more than 20 years. The same trend is shown with increasing age. Unlike younger workers, when smokers and nonsmokers more than or equal to 40 years of age are compared, prevalence rates of air flow impairment are not statistically different. The present investigation is one of the few in which the effects of occupational exposure could be separated from and were found to predominate over the effects of smoking.

Adult↗
PubMed1975

Cardiac sensitivity to hyperkalemia in adrenalectomized dogs.

In dogs with bilateral adrenalectomy loaded with K by infusion of 2 mEq KCI/kg/hr there is a marked increase of cardiac sensitivity to hyperkalemia. Typical ECG changes begin at lower serum K levels (5-6 mEq/l) and the prelethal arrhythmias that signal the imminent onset of fatal when mean serum K is 7.6 mEq/l, 2.9 mEq/l above the average pre-infusion level. In control dogs, ECG changes start above 8 mEq K/liter, and prelethal arrhythmias appear between 9.5 and 10.2 mEq/l, a mean increase of 5.6 mEq/l above the average preinfusion level.

Adrenal Glands↗
PubMed1975

Delta Beta-Thalassaemia in two yugoslavian families.

Members of two Yugoslavian families were found to have delta-beta-thalassaemia. Interaction of beta-thalassaemia with delta-beta-thalassaemia occured in two young children producing a clinical condition which is somewhat less severe than that of homozygous beta-thalassaemia. Results from biosynthetic analyses indicate that the degree of globin chain imbalance in double heterozygotes for beta- and delta-beta-thalassaemia is similar to that in homozygous beta-thalassaemia. Fetal haemoglobin of all heterozygotes contained G-gamma and A-gamma chains in an average ratio of about 2:3 whereas that in the two double heterozygotes had G-gamma and A-gamma chains in a ratio of 3:2.

Adolescent↗
PubMed1975

A G gamma type of the hereditary persistence of fetal hemoglobin with beta chain production in cis.

In a new subclass of G gamma HPFH which has been detected in a black family, beta A chains are produced in cis to the HPFH determinant (the G gamma-beta+ HPFH). No other instance of beta chain production in cis to HPFH has been reported. All individuals in this family are well even if Hb S is produced in trans to HPFH. Genetically, this new subclass requires a slightly smaller deletion in the gamma, delta, and beta complex of genes than do other forms of HPFH. It is speculated that a subclass (the G gamma-(G gamma A gamma)-beta+ HPFH) in which beta S chains are produced in cis to HPFH in conjunction with true beta S genes in trans may be responsible for "mild" cases of sickle cell anemia.

Adolescent↗
PubMed1974

Cell wall and protoplast isoperoxidases in relation to injury, indoleacetic Acid, and ethylene effects.

In tobacco (Nicotiana Tabacum) pith, sweet potato (Ipomoea batatas), and carrot (Daucus carota) storage roots, differences were found between cell wall and protoplast peroxidases in their isoenzyme patterns, activity, and reaction to tissue injury.In the pith of elongating tobacco internodes, 90% of total activity was associated with the walls, 80% of which was due to the ionically and covalently bound fractions. With senescence, the increase in activity occurred mainly in the protoplast and the free fraction in the walls. The major protoplast isoperoxidases formed the free wall fraction, and the minor ones formed the wall bound fractions. The minor isoperoxidases were the only ones whose activities were affected by cut injury. Neither senescence nor injury caused qualitative changes in the cell isoperoxidase pattern. In the potato root cells, the isoperoxidases were also distinctive in their distribution and in their reactions to injury as well as to ethylene.In potato and carrot roots, the wall fractions contributed 30 and 95%, respectively, to total peroxidase activity. The injury-induced increase in peroxidase activity occurred mainly in the protoplast of tobacco pith and potato roots and almost entirely in the ionically bound fraction of the walls in carrot roots. Ethylene stimulated peroxidase development in potato roots, especially in the protoplast, but had no effect in either tobacco pith or carrot roots. Ethylene did not affect the inhibiting action of indoleacetic acid on peroxidase activity in tobacco pith, nor did indoleacetic acid significantly affect the stimulating action of ethylene in potato roots.Actinomycin D inhibited the injury-dependent development of peroxidase in tobacco pith, stimulated the injury- and ethylene-dependent peroxidase development in potato root, and had no effect on peroxidase development in carrot root. Cycloheximide prevented the increase in peroxidase activity in tobacco pith and potato root, but not in the carrot root. Thus, the enhancement of peroxidase activity resulted from either enzyme activation exclusively or from enzyme synthesis. RNA synthesis seems to be only indirectly related to isoperoxidase synthesis caused by injury or ethylene.

Journal Article↗