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Biomedical subjects

H Roels

Publications and source records attributed to H Roels.

At least 109 records · Page 6Linked to original sources
PubMed1985

Fertility of male workers exposed to mercury vapor or to manganese dust: a questionnaire study.

The fertility of male workers exposed to mercury vapor or to manganese dust was assessed with the use of the questionnaire developed by Levine et al [1980]. In the mercury group (concentration of mercury in urine ranging from 5.1 to 272.1 micrograms/g creatinine), no statistically significant difference was found between the observed number of children and that expected on the basis of the reproductive experience of a well-matched control group. On the contrary, by comparison with their corresponding controls, the manganese-exposed workers exhibited a statistically significant deficit in the number of children during their period of exposure to the metal. The airborne concentration of manganese dusts at the different workplaces ranged from 0.07 to 8.61 mg/m3 with a geometric mean of 0.94 mg/m3.

Adolescent↗
PubMed1985

Aneurysmal bone cysts in the cranial vault and base of skull.

Three cases of aneurysmal bone cyst of the skull are reported. The localization in the base of the skull (two cases) is extremely rare and simulates a space-occupying intracerebral lesion. The clinical and microscopic findings, and their significance for the differential diagnosis from malignant brain tumors, are described.

Adult↗
PubMed1985

The influence of AZQ on the DNA distribution of human cerebral tumours in short-term culture.

The influence of AZQ, a chemotherapeutic agent, on the DNA-distribution of human cerebral tumours in short-term culture was studied by means of a MPV II cytofluorometer. The cell cultures were exposed to increasing concentrations of AZQ during 5 days. The results showed that AZQ has no cell phase-specific activity. The influence on the DNA-distribution varied considerably in the examined tumours. It is hypothesised that the effect of AZQ might depend upon the initial DNA-distribution of human cerebral tumours, hyperdiploid tumours being more vulnerable.

Aziridines↗
PubMed1985

Comparative study between histochemical and biochemical estimation of estrogen receptors in tumors.

Sucrose gradient analysis (SDGC) was compared with histofluoroassay, using 17 beta-Estradiol-6-carboxymethyloxime-bovine serum albumin-fluorescein isothiocyanate (E2-BSA-FITC) as fluorescent ligand, for the estimation of estrogen receptors (ER) in human breast tumors. No correlation was seen between fluorescent ligand binding capacity by the tumoral tissues on the one hand and ER levels estimated by SDGC on the other hand. The fluorescent ligand had a lower affinity for the receptor than estradiol itself and was contaminated with free estradiol. It was concluded that the absence of correlation between both techniques was for the greatest part due to unspecific binding of E2-BSA-FITC.

Breast Neoplasms↗
PubMed1984

Mycosis fungoides and lymphoplasmacytoid immunocytoma in the same patient. A case report.

The simultaneous occurrence of two different lymphomas in a 57-year-old white woman is reported: mycosis fungoides and a leukemic lymphoplasmacytoid immunocytoma. The first was confirmed by histologic study and electron microscopy, and the latter by histologic study and immunoperoxidase staining. The lymphoid cells in the involved bone marrow and peripheral blood expressed the same surface immunoglobulin as was found in the cytoplasm of the immunocytoma cells, i.e., IgM-lambda. The clonal B-cell expansion was brought into a lasting remission by chlorambucil, but the cutaneous lymphoma proved to be refractory to therapy. The patient died 38 months after diagnosis.

Chlorambucil↗
PubMed1984

Cytochemical analysis of the chromatin of liver cell nuclei and nuclei of oval cells by means of the Feulgen hydrolysis curve in rats treated by thioacetamide.

The present study is an analysis of the Feulgen hydrolysis characteristics in nuclei of liver cells and oval cells in rats treated by thioacetamide (TAA) and of liver cells in control rats. The curves show a double-peaked pattern. A slower hydrolysis is noted in the first peak after TAA treatment. This suggests an alteration of the acid-labile part of the chromatin. The curve obtained in the oval cells is different from the one in the liver cells. The implications of these differences are discussed with respect to development of cholangiocarcinomas.

Acetamides↗
PubMed1984

Cytogenetic examination of leucocytes of workers exposed to mercury vapour.

Cytogenetic observations have been performed on male subjects occupationally exposed to elemental mercury in a plant where mercury is amalgamated with zinc and in a chloralkali plant [n = 22; average level of mercury in urine was 117 micrograms/g creatinine and of mercury in blood 3.1 micrograms/100 ml; mean duration of Hg exposure 4 years (range: 0.3-15.3)]. The exposure to mercury vapour did not result in an increased yield of structural chromosomal aberrations in peripheral blood lymphocytes of the workers. These negative results are in agreement with the findings reported for other eukaryotic systems and confirm that population monitoring based on cytogenetic examination of peripheral blood lymphocytes does not always represent a good indicator of damage to genetic material produced by a chemical.

Adult↗
PubMed1984

Environmental pollution by cadmium and cadmium body burden: an autopsy study.

The industrial area of Liège in Belgium is polluted by cadmium mainly because of past emission from non-ferrous metal industries. Persons who have lived in that area have accumulated significantly more cadmium in the renal cortex and in the liver than those who have resided in other regions of the country.

Belgium↗
PubMed1984

Urinary cadmium and lead concentrations and their relation to blood pressure in a population with low exposure.

The 24 hour urinary excretion of cadmium (U-Cd) and lead (U-Pb), and the excretion of beta-2- microglobulins and retinol binding protein concentration in spot urines, were determined in a random 4% sample of the population of a small Belgian town. Blood pressure and body weight were measured on two separate occasions. U-Cd averaged 2.4 nmol/24 h in 46 youths, increased with age, and was significantly higher in 57 adult men as compared with 59 women (9.3 v 7.2 nmol/24 h; p less than 0.01). U-Pb averaged 28 nmol/24 h in youths and similarly increased with age: adult men excreted more lead than women (64 v 40.0 nmol/24 h; p less than 0.001). Among men, manual workers excreted more cadmium (12.6 v 7.5 nmol/24 h; p less than 0.05) but a similar amount of lead (62 v 61 nmol/24 h) compared with office workers. After adjusting for sex and age, U-Cd and U-Pb were not related to body weight and cigarette consumption. In simple regression analysis, U-Cd was positively correlated with both systolic (r = +0.30; p less than 0.05) and diastolic (r = +0.38; p less than 0.01) blood pressure in women. After adjusting for other contributing variables, however, a weak but negative relation became apparent between systolic pressure and U-Cd in women (t = -2.21; p = 0.033) and between diastolic pressure and U-Cd in men (t = -2.04; p = 0.047). In women urinary beta-2-microglobulin was related to diastolic pressure (r-0.44; p<0.01) and after adjusting for age to both systolic (t=2.75; p=0.009) and diastolic (t=-3.07; p=0.004) pressure. In none of the sex-age groups did U-Pb and retinol binding protein contribute to the blood pressure variability.

Adolescent↗
PubMed1983

Significance of urinary metallothionein in workers exposed to cadmium.

Cadmium in blood (Cd-B) and in urine (Cd-U) and metallothionein (Mt-U) and beta 2-microglobulin in urine (beta 2m-U) were measured in 94 male Cd workers. The results were examined according to the workers' current exposure to cadmium (group C, n = 73, workers currently exposed to Cd; group R, n = 21, Cd workers removed from exposure or retired) and according to their renal status (group N, n = 66, normal beta 2m-U; group I, n = 28, beta 2m-U greater than 200 micrograms/g creatinine). The interrelationships between Mt-U, Cd-U, Cd-B and years of cadmium exposure were examined in the various subgroups. The study of the correlations between these variables demonstrates that Mt-U is directly correlated with Cd-U but not with Cd-B or years of Cd exposure. The association between Cd-U and Mt-U is independent of the status of renal function and the intensity of current exposure to cadmium. Under moderate chronic exposure to cadmium, the fraction of Cd-U which is directly influenced by recent exposure (Cd-B) is small in comparison with that influenced by the cadmium body burden.

Adult↗
PubMed1983

Anti-laminin antibodies in workers exposed to mercury vapour.

In 62 male workers exposed to mercury vapour for 5.5 years on average, the results of several renal parameters were not significantly different from those found in a well-matched control group (n = 60). Circulating anti-laminin antibodies were found, however, in 8 workers exposed to mercury vapour but in none of the control workers. These results suggest that occupational exposure to mercury vapour may lead to immune dysfunction in a certain percentage of the exposed population. Whether such a finding is predictive of the occurrence of an immune glomerulonephritis remains to be evaluated.

Antibodies↗
PubMed1983

The critical level of cadmium in human renal cortex: a reevaluation.

The previously published estimate (160 ppm) of the critical level of renal cortical cadmium (Cd) (Roels et al., Environ. Res., 26 (1981) 217-240) has been reassessed after the depth of the left kidney was measured in each worker by echography. The correction introduced for kidney depth demonstrates that the critical liver cadmium level of 30 ppm corresponds to a corrected critical level of cadmium in renal cortex of 216 ppm. This critical cadmium level in renal cortex (CdKc) protects probably more than 90% of male workers from developing Cd-induced renal dysfunction.

Cadmium↗
PubMed1983

The influence of orally-administered vitamin C or zinc on the absorption of and the biological response to lead.

A single-blind study was performed on male workers from a primary lead smelter to determine whether a daily oral supplement of vitamin C (1 g vitamin C orally once a day, five times a week for 20 weeks) or zinc (60 mg zinc as zinc gluconate once a day, five times a week for eight weeks) influences the absorption of and the biological (hematological and renal) response to lead. The vitamin C and the zinc study groups comprised 39 and 11 workers, respectively. Their blood levels of lead at the start of the experiment ranged from 28.9 to 76.4 micrograms/100 ml. A matched control group receiving a placebo was followed simultaneously. The results demonstrate that, in workers whose exposure to inorganic lead is moderate and who do not suffer from nutritional deficiencies, oral supplementation of vitamin C or zinc does not influence the metabolism and biological action of lead.

Absorption↗
PubMed1983

Sinus histiocytosis with massive lymphadenopathy in Rwanda: report of eight cases with immunohistochemical and ultrastructural studies.

The clinico-pathological, immunohistochemical and ultrastructural features of eight cases of sinus histiocytosis with massive lymphadenopathy (SHML) recorded in Rwanda from 1975 to 1980 are reported. The main histopathological features were a massive enlargement of the lymph node sinuses which were filled with large histiocytes, a great number of which phagocytosed blood cells, especially lymphocytes, and an important proliferation of plasma cells in the medullary cords. The pathogenesis of this syndrome is discussed, particularly the role of immunological disorders challenged by a chronic, but non-specific, infectious state. The ultrastructural study revealed no micro-organisms and no Langerhans' granules. Immunohistochemical staining revealed two interesting features: the presence of immunoglobulins in the cytoplasm of the histiocytes indicating the presence of an immune phagocytosis and the absence of lysozyme and alpha 1-antichymotrypsin (alpha 1-AC) from the histiocytes. The significance of the latter phenomenon is still unknown.

Adult↗
PubMed1983

Granular cell myoblastoma of the bronchus.

A case is described in which a right-sided bronchus tumour was found incidentally at endoscopic examination for left-sided pneumonia. No clinical or radiographic signs of this bronchial mass were present. Endoscopic biopsy proved the tumour to be a granular cell myoblastoma.

Biopsy↗
PubMed1983

Mediastinal angiofollicular lymph node hyperplasia with systemic manifestations.

This case report concerns a 19-year-old girl with a mediastinal angiofollicular lymph node hyperplasia (Castleman tumour), with histological aspects of both hyalin vascular and plasma cell type. Systemic manifestations were also noticed. A lymphocytic infiltration of the bone marrow and a change in the lactic dehydrogenase iso-enzyme pattern with an increase of LDH3 were noted. After surgical removal of the mediastinal tumour complete recovery and normalisation of biological abnormalities occurred.

Adult↗