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Biomedical subjects

H Roels

Publications and source records attributed to H Roels.

At least 145 records · Page 8Linked to original sources
PubMed1980

Cytophotometric DNA determination in human oligodendroglial tumours.

Cytophotometric DNA determination was performed on 11 surgically resected oligodendroglial tumours and on oligodendroglial cells in two normal brains. The results are compared with the histological findings, the mitotic index and the degree of clinical malignancy. In this type of glioma there is no correlation between the DNA pattern and the histological appearances and the mitotic index. It is concluded that an aneuploid DNA distribution curve corresponds to a bad prognosis, whilst a diploid DNA curve does not allow prediction of the degree of clinical malignancy.

Aneuploidy↗
PubMed1980

Assessment of renal function of workers exposed to inorganic lead, calcium or mercury vapor.

The renal function of workers occupationally exposed to cadmium (n = 148), to mercury vapor (n = 63) or to inorganic lead (n = 25) has been compared with that of workers with no occupational exposure to heavy metals (n = 88). A moderate exposure to lead (Pb-B < 62 microgram/100 ml) does not seem to alter renal function. Excessive exposure to cadmium increases the urinary excretion of both low- and high-molecular-weight proteins and of tubular enzymes. These changes are mainly observed in workers excreting more than 10 microgram Cd/g creatinine or with Cd-B above 1 microgram Cd/100 ml whole blood. Occupational exposure to mercury vapor induces glomerular dysfunction as evidenced by an increased urinary excretion of high-molecular-weight proteins and a slightly increased prevalence of higher beta 2-microglobulin concentration in plasma without concomitant change in urinary beta 2-microglobulin concentration. beta-galactosidase activity in blood and in urine is also increased. The likelihood of these findings is greater in workers with Hg-B and Hg-U exceeding 3 microgram/100 ml whole blood and 50 microgram/g creatinine, respectively. The hypothesis is put forward that the glomerular dysfunction induced by cadmium and mercury might result from an autoimmune mechanism.

Adult↗
PubMed1979

The determination of trace levels of arsenic in human biological materials.

The authors have reviewed the techniques developed for measuring the concentration of total arsenic and that of some specific arsenic species (As V, As III, aromatic and aliphatic arsenic derivatives) in biological materials mainly in urine. Whether the relative concentrations of these arsenical species found in human urine represent their true distribution in the urine secreted by the kidney (possible change in valence state in the bladder mainly at alkaline pH, breakdown of arsenical derivatives during urine pretreatment) remains to be investigated further. No technique is yet available for measuring specifically the organoarsenic derivative(s) excreted after ingestion of marine animals. No available system has been found that will digest tissues without changing the original valence states of arsenic. Therefore only total arsenic can be measured with accuracy in tissue.

Animals↗
PubMed1979

Vertebrobasilar insufficiency due to Tumoural emboli.

A case, which is clinically characterized by a subacute vertebrobasilar syndrome, is presented. The necropsy reveals multiple infarcts in brainstem, cerebellum and left cerebral hemisphere, due to tumoural emboli of a non-detected primary tumour. It is postulated that the latter has to originate in the lungs in order to produce this unique type of cerebral arterial embolism.

Adrenal Gland Neoplasms↗
PubMed1979

Renal excretion of proteins and enzymes in workers exposed to cadmium.

The proteinuria rate and the relative clearances of beta 2-microglobulin, orosomucoid, albumin, transferrin and IgG were measured in forty-two workers exposed to cadmium and in seventy-seven control workers. A tubular type proteinuria with an increased excretion of beta 2-microglobulin and often also a glomerular type proteinuria with an increased excretion of orosomucoid, albumin, transferrin and IgG were observed mainly in workers exposed to cadmium for more than 25 years and whose cadmium concentration in blood exceeded 1 microgram Cd/100 ml and that in urine 10 microgram Cd/g creatinine. The glomerular dysfunction was also suggested by an increased plasma level of beta 2-microglobulin and creatinine. Both tubular and glomerular impairments occurred with the same prevalence and were not necessarily associated. The increased release of beta-galactosidase by the kidney suggested that cadmium can damage some epithelial cells.

Adult↗
PubMed1979

Cytophotometric DNA determination in human astroglial tumours.

The DNA content is determined by the cytophotometric method in 16 astroglial tumours, classified according to the degree of clinical malignancy. The values are compared to those found in non-tumoural astrocytes. This method appears to be more reliable in assessment of the degree of malignancy of the tumour in biopsy material than histological criteria and the mitotic index. It is also shown to be of great value in cases where the biopsy is taken at the margin of the tumour and in which malignant histological features are missing.

Adolescent↗
PubMed1978

alpha 1-antitrypsin in cadmium toxicity: an evaluation of its suggested role.

Chowdhury and Louria [1] reported that cadmium could reduce in vitro the concentration and the trypsin inhibitory capacity of plasma alpha 1-antitrypsin. They suggested that this could explain the emphysema observed in some workers exposed to cadmium. Using the same experimental approach as these authors, we could not reproduce their observations. Furthermore, in vivo results obtained on workers excessively exposed to cadmium during more than 20 years and exhibiting obvious signs of chronic cadmium intoxication did not reveal a decrease in the concentration and the activity of plasma alpha 1-antitrypsin.

Cadmium Poisoning↗
PubMed1978

Influence of sex hormones on free erythrocyte protoporphyrin response to lead in rats.

Following oral administration of lead a difference in free erythrocyte protoporphyrin (FEP) increase was found between adult male, adult female and suckling rats: young animals are more susceptible than adult female rats which in turn exhibit a greater FEP increase than adult male animals. This observation parallels that made previously in humans. Possible difference in iron metabolism does not appear to explain the sex-linked difference in FEP response to lead. Sex hormones mainly progesterone, seem to play a role but their interaction with lead on the FEP response is restricted to female rats and apparently is not mediated through changes in delta-aminolevulinic acid synthetase activity.

Age Factors↗