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Biomedical subjects

H Roels

Publications and source records attributed to H Roels.

At least 91 records · Page 5Linked to original sources
PubMed1989

The expression of the neu oncogene product in breast lesions and in normal fetal and adult human tissues.

The expression of the neu oncogene product was investigated in invasive and non-invasive ductal carcinomas of the breast, non-neoplastic lesions of the breast, fragments of normal adult and fetal breasts and in several other normal and fetal tissues at different weeks of pregnancy by means of an immunohistochemical study with monoclonal antibodies. The staining pattern along the cytoplasmic membrane was specific for malignancy and occurred in 29% of the breast carcinomas. It was observed in invasive carcinomas as well as in ductal carcinoma in situ and it showed a significantly higher expression in premenopausal women than in postmenopausal women. This higher expression was also present in oestrogen receptor-negative tumours. The tubules of the fetal and adult kidney, the absorption cells of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult small and large intestine, the sebaceous glands of the fetal and adult skin, the adult endocervix, the endometrium, the C-cells of the thyroid, hepatocytes and all ductal cells of the fetal breast showed a constant diffuse intracytoplasmic granular staining. staining. The same granular intracytoplasmic staining pattern was focally observed in rare cases of normal breast tissue in adults and in some cases of epitheliosis, aprocrine metaplasia and some breast carcinoma cells, which did not express neu oncogene product on their membrane. Western blot experiments showed that the cytoplasmic protein had a molecular weight of 155 kD (kilodaltons); the membrane protein is the known 185 kD neu protein.

Adult↗
PubMed1989

Crohn's disease with adenocarcinoma and dysplasia. Macroscopical, histological, and immunohistochemical aspects of two cases.

We present two cases of small-bowel adenocarcinoma and dysplasia in patients with longstanding Crohn's disease. In one case, the dysplasia and cancer were exclusively located in the terminal ileum, whereas in the other case, several cancers were found from the ileum toward the transverse colon. In both cases, we found a clinically unsuspected Dukes C1 mucinous adenocarcinoma together with large foci of polypoid villous dysplasia or with multifocal high-grade dysplasia and intramucosal carcinoma. Immunohistochemical staining for carcinoembryonic antigen (CEA) revealed a different staining pattern in various diseased areas. The intensity of CEA staining paralleled the histologic degrees of dysplasia and neoplasia. Cytokeratin expression was disturbed in inflamed mucosa, and it was more pronounced in high-grade dysplasia and invasive carcinoma. We conclude that the presence of dysplasia in an intestinal biopsy of a patient with Crohn's disease should arouse the pathologist's suspicion of carcinoma and force him or her to take multiple sections from strictures and polypoid lesions, especially since the clinical symptoms of a carcinoma may be obscured by the symptoms of inflammatory bowel disease. Immunohistochemical staining with CEA and cytokeratin are useful in the objectivation of dysplasia.

Adenocarcinoma↗
PubMed1988

Testicular toxicity induced by single dosing of di- and mono-(2-ethylhexyl) phthalate in the rat.

The testicular toxicity of di-(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, and of its major metabolite, mono-(2-ethylhexyl) phthalate (MEHP), was assessed after a single dose in rats. Treatment with a single dose of 2.8 g/kg DEHP or 0.8 g/kg MEHP was sufficient to induce testicular atrophy as observed 7 days after dosing. Such a treatment had no effect on plasma FSH levels, and had varying effects on testicular zinc concentrations. After a single dose of 0.8 g/kg MEHP the testicular toxicity was age-dependent, in that only prepubertal rats were susceptible.

Animals↗
PubMed1988

Immunoglobulin containing cells in terminal ileum and colorectum of patients with arthritis related gut inflammation.

In 40 distal ileal and 40 colonic biopsies of arthritic patients mostly without gastrointestinal symptoms, but with histological evidence of acute or chronic inflammation of the gut, the number of immunoglobulin (Ig) containing plasma cells was studied morphometrically using a peroxidase antiperoxidase technique. Compared with controls, the ileal mucosal biopsies showed an increase of IgA and IgG in acute ileitis. In chronic ileitis there was an increase of IgA, IgG, and IgM similar to Crohn's disease. In colonic biopsies there was a significant increase of all immunoglobulin classes in acute inflammation. In chronic inflamed mucosa there was also an increase of all three Ig classes. The Ig distribution, however, was significantly different in acute and chronic colitis. These findings give immunohistochemical evidence of the existence of two different types of inflammation related to reactive arthritis or the peripheral joint involvement of ankylosing spondylitis. The Ig pattern in acute colitis is similar to that found in infectious colitis, suggesting an enterobacterial origin of the arthritis in this group of patients although bacteriological and serological investigations were negative. In the chronic type of arthritis related ileocolitis, the pattern of Ig containing cells is similar to that found in Crohn's disease but different from infectious and ulcerative colitis, which makes the hypothesis that a great number of these arthritis patients suffer from asymptomatic or subclinical Crohn's disease acceptable.

Adolescent↗
PubMed1988

The relationship between blood pressure and environmental exposure to lead and cadmium in Belgium.

The question whether in the general population environmental exposure to lead and cadmium influences blood pressure after controlling for confounding factors remains debated. The environmental exposure of the Belgian population to both lead and cadmium is high as compared with other countries. The Cadmibel Cooperative Study was therefore designed to elucidate whether environmental exposure to lead and cadmium has any effect on blood pressure and renal function in the population at large. Before embarking on the large Cadmibel project, a small study was conducted. Blood pressure and the 24-hr urinary excretion of cadmium (CdU) and lead (PbU) were determined in a random 4% sample of the population of a small Belgian town. CdU averaged 0.27 micrograms/24 hr in 46 youths (mean age 14 +/- 3 years, +/- SD), increased with age, and was higher in 57 adult men (age 41 +/- 14 years), as compared with 59 adult women (age 39 +/- 14 years) (1.05 vs. 0.81 micrograms/24 hr; p less than 0.01). PbU averaged 5.8 micrograms/24 hr in youths and similarly increased with age; adult men excreted more lead than women (13.3 vs. 8.3 micrograms/24 hr; p less than 0.001). Among men, manual workers excreted more cadmium (1.4 vs. 0.8 micrograms/24 hr; p less than 0.05) but a similar amount of lead (7.0 vs. 6.9 micrograms/24 hr) as compared with office workers. In simple regression analysis, CdU 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.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Limb conservation in primary bone tumours by resection, extracorporeal irradiation and re-implantation.

En-bloc resection, extracorporeal irradiation and re-implantation of the irradiated bone have been used to treat 15 patients suffering from primary malignant tumours of bone or cartilage and two with benign lesions. This treatment is an alternative to replacement by prosthesis or allograft bridging techniques. After a mean follow-up of over five years results are encouraging, despite some complications and the relatively long period before weight-bearing is allowed.

Adolescent↗
PubMed1987

Relationship between external and internal parameters of exposure to manganese in workers from a manganese oxide and salt producing plant.

In a plant producing manganese (Mn) oxides and salts, 11 different workplaces were identified. The current exposure to airborne Mn (total dust, personal sampling, n = 80) varied from 0.07 to 8.61 mg/m3. The geometric mean and median values amounted approximately to 1 mg/m3 and the 95th percentile was 3.30 mg/m3. The concentration of Mn in blood (Mn-B) in a group of 141 Mn-exposed male workers ranged from 0.10-3.59 micrograms/100 ml compared to 0.04-1.31 micrograms/100 ml in a group of 104 control subjects. The ranges of the concentrations of Mn in urine (Mn-U) were 0.06-140.6 and 0.01-5.04 micrograms/g creatinine for the exposed and control groups, respectively. The average level of Mn-B in the Mn group was more than twice as high as in the control group (arithmetic mean, 1.36 vs 0.57 microgram/100 ml) and that of Mn-U was ten times higher in the Mn group (geometric mean, 1.56 vs 0.15 microgram/g creatinine). The Mn-B level did not change significantly after 8 h of Mn exposure, whereas the Mn-U level dropped rapidly when exposure ceased (half-life less than 30 h). On an individual basis, neither Mn-B nor Mn-U correlated with the current levels of Mn-air or duration of Mn exposure. There was also no relationship between Mn-B and Mn-U. On a group basis, there was no correlation between the mean Mn-B levels and the current levels of Mn-air at each workplace.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Epidemiological survey among workers exposed to manganese: effects on lung, central nervous system, and some biological indices.

A cross-sectional epidemiological study was carried out among 141 male subjects exposed to inorganic manganese (Mn) in a Mn oxide and salt producing plant (mean age 34.3 years; duration of exposure, mean 7.1 years, range 1-19 years). The results were compared with those of a matched control group of 104 subjects. The intensity of Mn exposure was moderate as reflected by the airborne Mn levels and the concentrations of Mn in blood (Mn-B) and in urine (Mn-U). A significantly higher prevalence of cough in cold season, dyspnea during exercise, and recent episodes of acute bronchitis was found in the Mn group. Lung ventilatory parameters (forced vital capacity, FVC; forced expiratory volume in one second, FEV1; peak expiratory flow rate, PEFR) were only mildly altered in the Mn group (smokers) and the intensity and the prevalence of these changes were not related to Mn-B, Mn-U, or duration of exposure. There was no synergistic effect between Mn exposure and smoking on the spirometric parameters. Except for a few nonspecific symptoms (fatigue, tinnitus, trembling of fingers, increased irritability), the prevalence of the other subjective complaints did not differ significantly between the control and Mn groups. Psychomotor tests were more sensitive than the standardized neurological examination for the early detection of adverse effects of Mn on the central nervous system (CNS). Significant alterations were found in simple reaction time (visual), audioverbal short-term memory capacity, and hand tremor (eye-hand coordination, hand steadiness). A slight increase in the number of circulating neutrophils and in the values of several serum parameters (ie, calcium, ceruloplasmin, copper, and ferritin) was also found in the Mn group. There were no clear-cut dose-response relationships between Mn-U or duration of Mn exposure and the prevalence of abnormal CNS or biological findings. The prevalences of disturbances in hand tremor and that of increased levels of serum calcium were related to Mn-B. The response to the eye-hand coordination test suggests the existence of a Mn-B threshold at about 1 microgram Mn/100 ml of whole blood. This study demonstrates that a time-weighted average exposure to airborne Mn dust (total dust) of about 1 mg/m3 for less than 20 years may present preclinical signs of intoxication.

Adult↗
PubMed1987

Extranodal non-Hodgkin's lymphoma of the head and neck.

Forty-six patients referred to our department between 1970 and 1982 with biopsy proven extranodal non-Hodgkin's lymphoma (NHL) of the head and neck were analysed. The median follow-up was 78 months. As a result of histological revision, six cases were excluded. By retrospective staging, 10 patients were found to have advanced disease (stage IV) at the moment of presentation, and three showed infradiaphragmatical nodes (stage III). All stage I-II patients except one were treated with radiotherapy. The 5-year actuarial relapse-free survival was 50% for the whole group, and 77% for the 26 patients who achieved complete remission after initial treatment. All stage IV patients died from lymphoma. Initial response and localised disease were the most significant prognostic features.

Adolescent↗
PubMed1987

A suspected case of late-onset sodium-valproate-induced hepatic failure.

A 15-year-old boy was under anti-epileptic medication (diphenylhydantoine, phenobarbital and Na valproate) for more than five years. He was admitted in cerebral coma and died after 24 hours. The histological findings suggest a valproate induced liver toxicity. This long interval between start of treatment and a possibly related hepatic failure has not been described.

Adolescent↗
PubMed1987

Histopathology of intestinal inflammation related to reactive arthritis.

This study has identified a group of patients with inflammatory chronic, or relapsing acute arthritis who even in the absence of gastrointestinal symptoms have histological evidence of ileocolitis. At colonoscopy simultaneous biopsies of the terminal ileum and colon were taken from 108 patients with reactive arthritis (n = 55) or ankylosing spondylitis (n = 53), 47 patients with other rheumatic diseases and 19 control patients suffering from colonic polyps, adenocarcinoma, or chronic constipation. All control patients and all but one patient with rheumatoid arthritis, juvenile chronic arthritis, systemic lupus erythematosus, lumbar back ache, and psoriatic arthritis did not have histological evidence of acute or chronic inflammatory bowel disease. In contrast, in 30 of 35 (56.6%) patients with ankylosing spondylitis, and in 37 of 55 (67%) patients with reactive arthritis, regardless of HLA B27 phenotype, there was histological evidence of inflammatory bowel disease with features either of acute enterocolitis, or early Crohn's disease. Only 18 of 67 (27%) of the patients with histological gut inflammation, however, had intestinal symptoms.

Adolescent↗
PubMed1986

Influence of manganese on the gastrointestinal absorption of cadmium in rats.

Four groups of male rats were given the following oral treatment: control group (n = 20) deionized drinking water, Mn group (n = 20) deionized drinking water containing 56 ppm Mn2+ (1 mmol/l), Cd group (n = 10) deionized drinking water containing 112 ppm Cd2+ (1 mmol/l) and Cd + Mn group (n = 10) deionized drinking water containing 112 ppm Cd2+ and 56 ppm Mn2+. Half of each group was sacrificed after 4 weeks and the other half after 8 weeks of treatment. At each time interval, the mean levels of Mn in blood, in urine and in the various tissues did not differ between the control and Mn groups. Furthermore, comparable Mn levels were found after 4 and 8 weeks of treatment. Microscopical examination of the brain failed to reveal any overt morphological alteration in the Mn group. With respect to the control group, the Cd and Cd + Mn groups exhibited increased levels of Cd in blood, urine, liver, whole kidney, kidney cortex and in brain (cortex, cerebellum, basal ganglia), but the Cd + Mn groups showed invariably lower levels than the Cd group after 4 weeks as well as after 8 weeks. These results suggest that the rate of gastrointestinal absorption of Cd is decreased by supplementation of the drinking water with a 'non-toxic' dose of Mn2+.

Animals↗
PubMed1986

Hemangioendothelioma of the gingiva. Histopathologic and therapeutic considerations.

The hemangioendothelioma is a benign neoplasm, rarely observed in the mouth. In the literature, reports on the treatment and on the therapeutic results are lacking. This type of gingival neoplasm was observed in a young adult male. It was located in the attached gingiva in the upper and in the lower jaw, covering almost the entire coronal part of the anterior teeth. An exhaustive internal and neurological examination revealed no associated general disease. The gingival biopsies displayed the typical characteristics of a hemangioendothelioma: proliferation of the blood vessels, with a reduced lumen surrounded by swollen endothelial cells. The treatment consisted of a meticulous mechanical plaque control, chlorhexidine rinses, gingivectomy procedures and a monthly professional prophylaxis. 3 years after the periodontal treatment, the gingival structures remained clinically healthy. In the biopsies, only a small amount of inflammatory cells could be detected. This report shows a case of benign gingival neoplasms of unknown etiology in which meticulous plaque control, combined with extensive gingivectomies and repeated professional prophylaxis may have prevented or, at least, retarded the recurrence of the lesion.

Adolescent↗
PubMed1986

[Biological aspects of occupational exposure to cadmium and several other metals].

We have performed several cross-sectional epidemiological surveys among workers exposed to cadmium, mercury vapour or manganese in order to assess : their early biological or functional effects; the biological tests allowing an assessment of the amount of metal absorbed or stored in the body; the acceptable exposure levels. Studies have also been carried out among persons exposed to inorganic arsenic in order to define its inactivation mechanism and to develop a biological test of exposure. The kidney is the main critical organ following long-term exposure to cadmium. To prevent the occurrence of renal changes in the majority of male workers exposed to cadmium, its concentration in renal cortex should not exceed 215 micrograms/g (wet weight), and that in urine : 10 micrograms/g creatinine. A blood cadmium level of 1 microgram/100 ml has been suggested as maximum tolerable level for long-term exposure. Prolonged exposure to mercury vapour may lead to renal and neurological disturbances. The preclinical signs of nephrotoxicity are correlated with the amount of mercury absorbed which may be assessed by monitoring the mercury level in urine. The neurotoxic effects (particularly tremor) are mainly related to the integrated exposure (duration and intensity). A maximal permissible level of 50 micrograms Hg/g urinary creatinine is proposed to prevent the occurrence of these toxic effects. An exposure to manganese dust for 7 years on the average at a level below the maximum allowable airborne concentration (5 mg/m3) recommended by the ACGIH in the USA may still lead to a slight reduction in psychomotor and spirometric performances and interfere with calcium metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Arsenicals↗
PubMed1985

Preclinical toxic effects of manganese in workers from a Mn salts and oxides producing plant.

The results of the present epidemiological study among 141 workers (mean age: 34 years) from a Mn salts and oxides producing plant in Belgium suggest that preclinical perturbations (lung function, CNS, biological parameters) may occur in subjects exposed to airborne Mn levels (7 years on the average) usually lower (total dust, geometric mean about 1 mg/m3, 95th percentile 3.3 mg/m3) than the levels actually (5 mg/m3) tolerated.

Adult↗
PubMed1985

Surveillance of workers exposed to mercury vapour:validation of a previously proposed biological threshold limit value for mercury concentration in urine.

A cross-sectional epidemiological study was carried out among subjects exposed to mercury (Hg) vapour, ie, a group of 131 male workers (mean age: 30.9 yr; average duration of exposure, 4.8 yr) and a group of 54 female workers (mean age, 29.9 yr; average duration of exposure 7 yr). The results were compared with those obtained in well-matched control groups comprising 114 and 48 male and female workers, respectively. The intensity of current Hg vapour exposure was rather moderate as reflected by the levels of mercury in urine (HgU) (mean and 95th percentile: males 52 and 147 micrograms/g creatinine; females 37 and 63 micrograms/g creatinine) and of mercury in blood (mean and 95th percentile: males 1.4 and 3.7 micrograms/dl; females 0.9 and 1.4 microgram/dl). Several symptoms mainly related to the central nervous system (memory disturbances, depressive feelings, fatigue, irritability) were more prevalent in the Hg-exposed subjects. They were, however, not related to exposure parameters. In both male and female Hg-exposed workers no significant disturbances were found in short-term memory (audioverbal), simple reaction time (visual), critical flicker fusion, and colour discrimination ability. Only slight renal tubular effects were detected in Hg-exposed males and females, ie, an increased urinary beta-galactosidase activity and an increased urinary excretion of retinol-binding protein. The prevalence of these preclinical renal effects was more related to the current exposure intensity (HgU) than to the duration of exposure and was detected mainly when HgU exceeds 50 micrograms/g creatinine. Changes in hand tremor spectrum recorded with an accelerometer were found in the Hg-exposed males only. The prevalence of abnormal values for some hand tremor parameters (total velocity and total displacement in the 2-50-Hz band) was mainly increased in male workers exposed for more than 10 yr. Unlike the renal tubular effects, the preclinical signs of tremor were more related to the integrated exposure than to the current exposure. Since the female workers, who have been exposed to Hg vapour levels usually insufficient to increase their HgU levels above 50 micrograms/g creatinine, did not exhibit any change in hand tremor pattern, the results of the present study tend to validate our previously proposed biological threshold limit value of a HgU of 50 micrograms/g creatinine for workers chronically exposed to mercury vapour.

Belgium↗