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Biomedical subjects

C E Ross

Publications and source records attributed to C E Ross.

At least 91 records · Page 5Linked to original sources
PubMed1981

Testicular function among epichlorohydrin workers.

Epichlorohydrin (1,2-epoxy-3-chloropropane) (ECH) is a colourless liquid used in the production of insecticides, agricultural chemicals, epoxy resins, and many other productions. It is highly reactive and an alkylating agent suspected of possessing carcinogenic properties in man. The results of a clinical-epidemiological investigation to ascertain whether exposure to ECH may be associated with sperm count suppression among ECH production workers at two chemical plants are presented. Medical histories and physical examinations with special emphasis on the genitourinary tract were completed on each participant. Blood samples and three semen specimens were also obtained. Since no internal control group were available, the data arising from this effort were analysed for each plant (plant A, 44 men; plant B, 84 men) using a control group of 90 chemical plants workers unexposed to any agents known to be toxic to the tests who were included in previous studies. This study provides no evidence that exposure to ECH at the concentrations existing at the two plants studied is responsible for sperm count suppression.

Chemical Industry↗
PubMed1980

Dibromochloropropane and its effect on testicular function in man.

This study represents the largest series to date documenting the gonadotoxic effect in humans of dibromochloropropane, a widely used pesticide. Three semen analyses, serum hormonal determinations (luteinizing hormone, follicle-stimulating hormone and testosterone) as well as genital examinations were completed for 228 workers at 2 chemical production sites and consisting of a dibromochloropropane-exposed and non-exposed cohort. Parameteric and non-parametric statistical analyses of the data sets of the sperm densities from the 2 subpopulations demonstrated statistical significance (p less than 0.10) at the short-term (1.5 years) manufacturing plant. Log transformation of the sperm count and hourly exposure data were necessary to develop meaningful statistical conclusions. The serum concentration of follicle-stimulating hormone as a group mean was significantly greater at both production sites for the exposed cohort when compared to the non-exposed participants but decreased by 10 levels of magnitude when the group demonstraing shorter but more recent exposure was compared to those from the plant with longer chemical production. Finally, a dose-response model suggested significant changes in sperm density at the short-term but more recently operated production site when more than 100 adjusted hours of exposure were exceeded, while the longer operated but longer closed facility demonstrated a significant impairment only when more than 1,000 adjusted hours of dibromochloropropane exposure were surpassed. This difference in exposure data may reflect regenerative changes in the tests once the gonadotoxic substance had been removed but exact nature of the dibromochloropropane effect and the possibility of a "no effect" concentration remain to be defined clearly.

Antinematodal Agents↗
PubMed1979

Indirect leukocyte migration assay in patients with malignant melanoma.

Leukocytes from 72 melanoma patients and 75 control donors were examined in a two-stage (indirect) leukocyte migration assay, using formalin-fixed melanoma cells (FMC) and control, normal or non-melanoma tumour cells (FCC) as the source of antigen. Inhibitory supernatants were produced significantly more often by cultures of melanoma leukocytes and FMC than by melanoma leukocytes and FCC or control leukocytes and FMC or FCC. Reactive leukocytes were most frequently derived from stage II patients (65%), followed by stage I patients with tumour present (58%), stage III patients (29%) and stage I patients without detectable tumour (20%). The likelihood that a melanoma patient's leukocytes would react increased progressively with the number of different FMC preparations tested. A similar, though less steep increase in reactivity was seen with control donor leukocytes and different FMC preparations. No significant increase in reaction frequency was seen with melanoma or control leukocytes exposed to increasing numbers of different FCC preparations. Significant discrimination between melanoma patients' and control donors' leukocytes was achieved with FMC from both primary and metastatic tumours. Concordance of positivity or negativity was seen in 60% of concurrent one-stage and two-stage leukocyte migration assays.

Adult↗
PubMed1976

Leukocyte migration inhibition by cancer patients' sera.

Sera from 38 of 89 melanoma patients, 4 of 15 patients with other cancers and 3 of 43 control donors inhibited the migration of autologous leukocytes. Sera from patients with clinically detectable metastatic disease and from the recipients of BCG were most frequently inhibitory. Autologous sera from 31 of 71 melanoma patients and 3 of 31 control donors increased the leukocyte migration inhibition induced by formalinized melanoma cells. This activity occurred in sera from patients at all stages of malignancy, whether bearing detectable tumour or not and whether receiving BCG or not. Abrogation of tumour-cell-induced leukocyte migration inhibition by serum was less frequent, occurring with 8 of 71 melanoma patients (6 Stage III, 1 Stage I and 1 Stage II) and no control sera. Preincubation of formalinized tumour cells had no effect on their activity in the leukocyte migration assay but the preincubation of melanoma leukocytes with either autologous serum or foetal calf serum inhibited leukocyte reactivity in around 50% of tests. However, this was also seen with control leukocytes and the effect appears to be immunologically non-specific.

Animals↗
PubMed1976

An examination of the immunology of cancer patients.

We have examined 111 cancer patients and 111 control individuals for general immunocompetence (haematological values, "recall" antigen skin tests, PHA and PPD induced lymphocyte transformation, serum Ig levels and lymphocyte subpopulations), for evidence of sensitisation to tumour-associated antigens (leucocyte migration test, serum inhibition of autologous leucocyte migration, lymphocytotoxicity, membrane immunofluorescence and immune adherence) and for evidence of continuing immune reactions (alterations of complement components and anticomplementary activity). Major differences between the cancer patients and controls were demonstrated by several tests of sensitisation and these also detected differences between patients with and without metastases. The only differences detected between cancer patients and controls by the tests of general immunocompetence were in serum IgG and IgA (higher in the cancer patients) and lymphocyte subpopulations ("active" T, autorosetting lymphocytes and lymphocytes forming "super-rosettes" increased in cancer patients). In a comparison of cancer patients with and without metastases, patients with metastases were less often reactive to the Candida DHS and streptokinase-streptodornase antigens and had raised circulating Fc positive cells. Abnormalities of the individual components of complement occurred in about half the cancer patients, but were equally common in those with and without metastases. Serum anti-complementary activity was very rarely detected. The tests of specific sensitisation correlated reasonably well but correlations of tests of general immunocompetence were infrequent.

Adolescent↗
PubMed1976

Sensitisation of neuroblastoma patients and related and unrelated contacts to neuroblastoma extracts.

Sensitisation to neuroblastoma extracts was tested by the leucocyte migration inhibition technique in 8 neuroblastoma patients, 22 relatives, and 49 unrelated contacts. All three groups showed a high frequency of positive reactions compared with 61 controls having no exposure to neuroblastoma. The frequency of sensitisation could be related to closeness of contact, but the nature of the sensitising material and its mode of transmission are unknown. Virus studies by the sensitive techniques of tumour virology are suggested. The absence of case clustering and the low familial incidence of neuroblastoma indicate that simple exposure to the tumour is not a major oncogenic factor.

Age Factors↗
PubMed1975

Hemochromatosis. Pathophysiologic and genetic considerations.

The clinical, genetic, and pathologic findings, and the pertinent case histories in two families with idiopathic hemochromatosis are presented. These studies support the view that idiopathic hemochromatosis is a disease inherited in at least two ways. In one of these families, inheritance appeared to occur in an autosomal recessive manner, whereas in the other, autosomal dominant expression seemed evident. Evidence that an inability of the reticuloendothelial cells to handle iron may play a major role in the pathogenesis of hemochromatosis is presented. The early age of onset and poorer prognosis associated with the recessive inheritance suggest that the defect in reticuloendothelial cell function present in such cases is different from or more severe than those associated with dominant inheritance.

Adolescent↗
PubMed1975

Formalinized tumour cells in the leucocyte migration inhibition test.

Immunization studies indicate that formalinized tumour cells retain at least part of their gross membrane structure and antigenicity; they are relatively easy to prepare and store well over a period of months. We have used formalinized tumour cells as antigen in the leucocyte migration inhibition test. Leucocyte migration inhibition occurred in leucocytes from thirty-eight out of sixty-nine malignant melanoma patients and from fifty-five out of eight-one breast cancer patients when in contact with formalinized tumour cells of a histologically similar type. Melanoma patients' and breast cancer patients' leucocytes were infrequently inhibited on contact with cells from histologically dissimilar human tumours and from xenogeneic mouse melanomas. Other advantages of formalinized cells over antigens prepared by homogenizing tumour tissue include a greater degree of inhibition and the ability to demonstrate a dose-response relationship between the ratio of leucocytes:tumour cells and the migration index.

Antigens, Neoplasm↗