Search PubMed⌕ Search

Biomedical subjects

R W Miller

Publications and source records attributed to R W Miller.

At least 145 records · Page 8Linked to original sources
PubMed1982

Treatment of lymphocytic thyroiditis with spontaneously resolving hyperthyroidism (silent thyroiditis).

The duration of the hyperthyroidism associated with lymphocytic thyroiditis (LT) with spontaneously resolving hyperthyroidism (SRH) was serially monitored in groups of patients who were not given any treatment (control subjects) or treated with propylthiouracil and/or propranolol hydrochloride and prednisone. The length of time for the thyroxine tests from diagnosis to the normal range was 57 +/- 17, 45 +/- 13, and 15 +/- 7 days (mean +/- SD) indicating a dramatic response to prednisone therapy but none to propylthiouracil and/or propranolol therapy. Five patients were found who had seven episodes of SRH while receiving thyroid hormone suppression therapy after having verified chronic LT (two patients) and LT-SRH (three patients). This indicates that thyroid suppression with thyroid hormone may be ineffective in preventing this disease. Two patients were treated by subtotal thyroidectomy because of recurrent or prolonged episodes of SRH. From this experience, the therapeutic alternatives available to the clinician are reviewed.

Humans↗
PubMed1982

Bilateral retinoblastoma with ectopic intracranial retinoblastoma: trilateral retinoblastoma.

In 11 patients, bilateral retinoblastoma presented at a mean age of 6 months and pineoblastoma at 4 years. We suggest that the hereditary multicentric retinoblastoma arose in vestigeal photoreceptors in the pineal as well as in the hypothetical retinoblasts of the retina. In certain lower animals, the pineal functions as a photoreceptor organ, resembles the retina histologically, and is described as a "third eye." Hence, the patients we describe may be considered as having "trilateral retinoblastoma." Two possible variants of this entity were also noted: (1) three children without retinoblastoma with rosettes and photoreceptor differentiation characteristic of retinoblastoma, and (2) three additional cases involving children who presented with retinoblastoma-like tumors in the suprasellar or parasellar region 2 to 6 months before the discovery of intraocular retinoblastoma. These observations suggest that the retinoblastoma gene confers a previously unappreciated susceptibility to a narrow spectrum of neuroblastic tumors, which usually present in the retina but which can also occur ectopically.

Brain Neoplasms↗
PubMed1982

Spin-Probe Studies during Freezing of Cells Isolated from Cold-Hardened and Nonhardened Winter Rye : MOLECULAR MECHANISM OF MEMBRANE FREEZING INJURY.

Mesophyll cells isolated from cold-hardened and nonhardened winter rye (Secale cereale L. cv. Puma) were spin-labeled with the fatty-acid spin probe N-oxyl-4,4-dimethyloxazolidine 5-ketostearic acid. The probe was intercalated within the cellular membranes and changes in probe motion were followed during extracellular freezing of the cells. A correlation was observed between the lethal freezing temperatures (LT(50)) of the cells and the maximum hyperfine splitting value achieved by the incorporated probe. Rigid limit spectra indicated that a more ordered average packing was attained by membranes of hardened cells which survived freezing to lower temperatures.Nonhardened cells fixed with osmic acid at lethal freezing temperatures, in the frozen state, showed both conversion of normal bilayered cellular membrane ultrastructure to an amorphous state and condensation of cellular membranes to form densely packed multibilayered vesicles. Taken together with the spin-labeling data, these results suggest that at least one molecular mechanism of extracellular freezing injury involves the irreversible conversion of planar membrane bilayers to structures having less ordered packing and increased surface curvatures.

Journal Article↗
PubMed1982

Relative Efficacy of Different Alfalfa Cultivar-Rhizobium meliloti Strain Combinations for Symbiotic Nitrogen Fixation.

Five Rhizobium meliloti isolates known to have different capabilities for expression of nitrogenase activity under symbiotic conditions were used to inoculate four representative Medicago sativa cultivars under aseptic conditions. Nitrogenase activities and respiratory activity were measured for whole plants and excised nodules. Dry weights and nodule numbers were also recorded after 4 weeks of growth in plastic pouches on a nitrogen-free nutrient medium. Hydrogen evolution and acetylene reduction rates were used to calculate the fraction of reducing power allocated to dinitrogen reduction. Although the efficiency of the system defined in this way was poorly correlated with plant yield, a very high linear correlation was obtained between yield and the algebraic product of nitrogenase activity and efficiency. High correlation (r > 0.78) was obtained between respiration and nitrogenase activity for whole plants as well as for excised nodules. Nodular respiration accounted for between 10 and 20% of the total plant dark respiration. The four test cultivars exhibited significantly different symbiotic responses to the inocula, although trends in potential for expression of the nitrogenase system by the five R. meliloti strains were evident. There was significant interaction between the host plant and symbiont in determining nitrogenase activity and yield. This screening method allows quantitative discrimination between effective and ineffective host-inoculum combinations.

Journal Article↗
PubMed1982

Correlation between cancers of the uterine cervix and penis in China.

A national survey of cancer mortality in the People's Republic of China during 1973--75 revealed concurrent geographic variation for cancers of the uterine cervix and penis, including clustering of both tumors in central parts of the country. The findings are consistent with recent reports from other countries that the cancers tend to aggregate in spouses and with the hypothesis of an etiologic factor in common.

China↗
PubMed1981

Areawide chemical contamination. Lessons from case histories.

Nine case histories illustrate the mounting problems owing to chemical contamination that often extends beyond the workplace into the community. The effects include not only carcinogenesis and teratogenesis, so much in the public's mind, but also severe neurological and gonadal disabilities immediately after exposure. Recognition of causal relationships is often made by astute clinicians. The experience of the Atomic Bomb Casualty Commission in studying Japanese survivors in Hiroshima and Nagasaki serves as a model for future studies of communities exposed to unusual environmental contamination.

Adult↗
PubMed1981

Potential effects of Thiram on Medicago - R. meliloti symbiotic association.

The effects of Thiram and 2 commercial Thiram formulations on the growth and respiration of rhizobia were tested to compare the extent of bacteriostasis under controlled conditions. Although bacteriostasis was measurable at all concentrations tested, liquid cultures grew to maximum optical density in Thiram suspensions containing less than 10 micrograms/ml. Percentage germination, root elongation, and subsequent nodulation by R. meliloti of 2 cultivars of alfalfa, were determined in thiram suspensions to determine potential physiological effects of the fungicide on the host plant. Conditions were identified which produced enhancement or inhibition of germination, root elongation and development of nodular nitrogenase activity. At concentrations of the fungicide recommended for seed application, only minor, temporary bacteriostasis was observed as a possible negative effect while germination rates of fungi-contaminated seed were markedly increased.

Dose-Response Relationship, Drug↗
PubMed1981

The effect of methoprene as a feed additive on house fly emergence in poultry houses.

Field trials were conducted in 1974 and 1975 using an encapsulated formulation of methoprene (AltosidTM) applied as a feed additive at rates of 7.5 and 10.0 ppm (AI in feed) to control Musca domestica L. in poultry houses. Only limited inhibition of house fly emergence was obtained. In addition, the percentage of house fly emergence in each trial gradually increased as the season progressed. Comparison bioassays were conducted at the end of the 1975 season between field-pressured strains and lab-reared susceptible strains. Results from the field trials and comparison bioassays indicated that the causes of the poor inhibition were an existing cross-resistance to methoprene followed by an induction of resistance resulting from the continuous exposure to methoprene.

Animal Feed↗
PubMed1981

Contrasting epidemiology of childhood osteosarcoma, Ewing's tumor, and rhabdomyosarcoma.

Marked dissimilarities in the epidemiology of osteosarcoma, Ewing's tumor, and rhabdomyosarcoma indicate differences in their origins. A major clue to the genesis of Ewing's tumor comes not from defining persons at high risk but from the observation that blacks are at unusually low risk. The neoplasm does not aggregate in families and is not part of any known syndrome. No environmental causes have been identified. By contrast, osteosarcoma may be caused by external or internal ionizing radiation, and it aggregated in families with the same tumor or with dissimilar tumors and in certain genetic disorders of bone. In man and in dogs, the frequency of the neoplasm is related to bone mass and growth. Rhabdomyosarcoma of the upper versus the lower limbs seems related to muscle mass. Age peaks in the occurrence of the tumor elsewhere vary with the anatomic site; head and neck tumors develop in early childhood and urogenital tumors both in early years and in adolescence. The sex ratio (male to female) also varies with the site affected. Rhabdomyosarcoma aggregates with certain other tumors in families and overlaps with osteosarcoma in some of these relationships but is distinguished from that tumor by its excessive occurrence in neurofibromatosis.

Adolescent↗