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Biomedical subjects

C E Nelson

Publications and source records attributed to C E Nelson.

12 recordsLinked to original sources
PubMed1991

Incidence of molds and mycotoxins in commercial animal feed mills in seven midwestern states, 1988-1989.

A total of 82 feed manufacturers located within seven midwestern states (Iowa, Nebraska, Minnesota, Illinois, Indiana, Ohio, Michigan) participated in a survey of mold and mycotoxin contamination of corn. Samples were submitted from a composite of the grading samples taken from each incoming load of corn. The survey was initiated in July 1988. During the 12-mo period, moisture content of the corn samples upon receipt at the laboratory ranged from 10.5 to 13.3%. The greatest variation occurred in the springtime. Iowa's corn samples were driest (11.2%), and samples submitted from Ohio were wettest (12.8%). Mold counts averaged 2.63 x 10(4) per gram during the year. The predominant mold found was Fusarium sp. Samples were checked by black light and averaged 25.4% positive during the period. When assayed for mycotoxins, 19.5% of the samples were positive for at least one of the following: aflatoxin, zearalenone, T2 toxin and deoxynivalenol (vomitoxin). Aflatoxin and T2 toxin made up the majority of these samples containing toxin. The highest incidence of mycotoxin-contaminated corn (48%) occurred in samples submitted in July of 1988. Over the 12-mo period, the highest mycotoxin contamination occurred in Iowa, Illinois and Michigan. When samples were subjected to 90% relative humidity and 32 degrees C, an average of 3.9 d was required for mold growth to appear. After incubation, 24.7% of the samples contained one of the four toxins. The data indicate that mold and mycotoxin contamination of mixed samples of corn is widespread, even in the midwestern corn belt of the U.S.

Aflatoxins↗
PubMed1979

N-acetyltransferase phenotype and risk in urinary bladder cancer: approaches in molecular epidemiology. Preliminary results in Sweden and Denmark.

A variable but often significant proportion of urinary bladder cancer in urban areas can be attributed to occupational and cultural (cigarette smoking) situations associated with exposures to various arylamines. The variable N-acetylation of carcinogenic arylamines by human hepatic enzyme systems, the known genetic regulation and polymorphic distribution of this enzyme activity in humans, and the known enhanced susceptibility of individuals with the genetically-distinct "slow acetylator" phenotype to various arylamine toxicities, has prompted examination of possible correlations between N-acetyltransferase phenotype and urinary bladder cancer risk in rural and urban populations. In this context, N-acetylation is viewed as a component of detoxication pathways with respect to arylamine bladder carcinogenesis. In preliminary utilizations of this approach, a population of urban urinary bladder cancer patients from Copenhagen, Denmark displayed a 13% excess (p = 0.065) of individuals with the slow acetylator phenotype (46/71 = 64.8%) when compared to a Danish control population (38/74 = 51.4%). These data are consistent with the possibility that arylamines may play an etiological role in bladder cancer in this locale and that slow acetylator individuals may be at higher relative risk (1.74) than rapid acetylator individuals. As 95% of patients reported histories of smoking, it was not possible to isolate and examine smoking factors. In contrast, a population of rural urinary bladder cancer patients from Lund, Sweden, where bladder cancer incidence (20/100,000) (1971) is lower than in Copenhagen (43.8/100,000) (1968-72), no difference in slow acetylator distribution was observed between bladder cancer (80/115 = 69.6%) and Swedish control (79/118 = 66.9%) populations, indicating a relative lack of involvement of arylamines in the etiology of rural bladder cancer. Populations of "spontaneous" bladder cancer patients would be expected to contain variable portions of disease related to arylamine exposure and would be less likely to display a detectable correlation than would an industrial population with documentable arylamine exposure. Consequently, confirmation of this hypothesis is being pursued by examination of industrial populations in an effort to obtain an empirical estimate of relative risk for slow and rapid acetylator phenotypes. These studies involve exposure-matched workmen both with and without bladder cancer.

Acetyltransferases↗
PubMed1979

Characterization of different regions of the normal human urinary bladder by means of scanning electron microscopy.

A study of the normal human urinary bladder and the proximal urethra was performed using scanning electron microscopy (SEM). Biopsies were evaluated from 27 male patients with benign prostatic hyperplasia, without history or sign of urinary tract malignancy and with cystoscopically normal mucosal finding. The specimens were obtained from the dome, the side-walls and the trigone of the bladder. The characteristic surface architecture of the transitional epithelium was observed in different anatomical regions of the human urinary bladder.

Aged↗
PubMed1979

Surface characteristics of malignant human urinary bladder epithelium studied with scanning electron microscopy.

Biopsies were obtained from 28 male and seven female patients with cystoscopically and histologically confirmed urinary bladder carcionoma. Tissue specimens for light microscopy and scanning electron microscopy (SEM) were obtained from the tumours as well as from cystoscopically tumour-free mucosa of the dome, the lateral walls and the trigone of the urinary bladder and also from the proximal urethra. Certain surface structural changes, which seem to represent malignancy, present in different regions of the urinary bladder were detected by SEM, although not visible by light microscopy.

Aged↗
PubMed1979

Collection and evaluation of normal exfoliated urinary bladder cells in man using scanning electron microscopy.

Normal exfoliated urinary bladder cells were collected from midstream urine samples from 21 male patients. Procedures for urine filtration using Millipore filters of Nucleopore filters, cell fixation and preparation for scanning electron microscopy investigation were developed. Correlations were made between the surface morphology of exfoliated cells and that of biopsies from different anatomical regions of the urinary bladder. Scanning electron microsocopy (SEM) of exfoliated normal urinary bladder cells proved to be a more sensitive method for discovering cellular surface details than light microscopy. This information forms the basis for further SEM studies of cell surface alterations due to urothelial diseases.

Cell Membrane↗
PubMed1979

Scanning electron microscopy of exfoliated malignant and non-malignant human urothelial cells.

Midstream urine samples were taken from 35 patients with histologically diagnosed urinary bladder carcinoma, from 27 patients without history or sign of malignancy or infection in the urinary tract, and from eight patiens with cystitis. The urine was filtered through Millipore filters, or Nuclepore filters, pore size 5.0 microns, on which the cells were caught. From the same patients biopsies were obtained from different anatomic regions of the urinary bladders as well as from the carcinomas that were present. The filters and the biopsies were examined with scanning electron microscopy (SEM). The exfoliated cells trapped on the filters were in good morphological condition. Idential characteristics of the cell surface morphology were recognized in the biopsies and the exfoliated cells from each patient. In non-malignant cases the cells displayed the regional morphological charcteristics of the urinary bladder. Bacteria and an increased number of red and white blood cells were attached to the cell surface of numerous exfoliated cells in patients with cystitis, but no pleomorphic microvilli were detected in these patients. In cases of malignancy exfoliated cells with pleomorphic microvilli on their surface were detected. A large majority of the exfoliated cells shed in the urine with pleomorphic microvilli on their surfaces still retained enough regional surface characteristics to determine their origin. Some of the cells were completely covered with pleomorphic microvilli and it was impossible to determine their origin.

Biopsy↗
PubMed1978

Neutron spectra from deuteron and proton bombardment of thick lithium targets: potential for neutron therapy.

Neutron energy spectra and yields produced by the bombardment of thick lithium targets by deuterons and protons have been measured using the time-of-flight method. Measurements were made at angles up to 45 degrees for deuteron energies of 8, 12 and 15 MeV and a proton energy of 15 MeV. The average neutron energy of the (d, n) reactions is shown to vary approximately as 0.44Ed. The (p, n) reaction has En = 4.7 MeV. The tissue penetration of neutron therapy beams is dependent on their average neutron energy and thus the low average neutron energy for these reactions appears to preclude their use for practical neutron therapy at these incident particle energies.

Deuterium↗
PubMed1977

Arcuate dermal erythema in a carrier of chronic granulomatous disease.

A female carrier of chronic granulomatous disease developed arcuate, erythematous dermal plaques on her back and face. The lesions were clinically and histopathologically suggestive of Jessner benign lymphocytic infiltration of the skin. Some women with relatively fixed arcuate or annular, erythematous, dermal plaques may be carriers of chronic granulomatous disease.

Erythema↗
PubMed1976

Attitudes and feelings of criminal justice personnel toward the mentally ill.

The present study compared the attitudes and feelings of law-enforcement, corrections, parole and probation personnel, and college students toward mental illness. Modified versions of the Criminally Insane Scale (Khanna, Pratt, & Gardiner, 1962) and Attitudes Toward Mental Illness Scale (Cohen & Struening, 1962) were used in assessing these attitudes. Law-enforcement and corrections personnel tended to believe many of the stereotypic causes of mental illness, while the college students based their views on more current thinking. In addition, law-enforcement and corrections personnel indicated greater fear of the criminally insane than the other two groups. Possible causes and ramifications of these differences are discussed.

Attitude to Health↗
PubMed1976

Study of glomerular and tubular function after in situ cooling of the kidney.

Ischemia of the kidney for 3 hours at a temperature of 16 to 18C will only impair renal function to a minimal degree measured by glomerular (51Cr ethylenediaminetetracetic acid) and tubular (125I hippuran) clearances. A newly developed device for surface cooling is described. The technique of clinical in situ surface cooling is recommended whenever an ischemia time for more than 10 minutes is expected.

Animals↗
PubMed1975

CHRC eating aid.

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Child↗