Biomedical subjects

U Van Haelst

Publications and source records attributed to U Van Haelst.

5 recordsLinked to original sources

PubMed1994

Complex composition and co-amplification of SAS and MDM2 in ring and giant rod marker chromosomes in well-differentiated liposarcoma.

Extra abnormal chromosomes (rings and giant rods) containing chromosome 12 sequences are characteristic of well-differentiated liposarcoma (WDLPS). By whole chromosome painting we found in 6 WDLPS that minimally 5 chromosomes had contributed to the formation of the extra abnormal chromosomes. To the constant chromosome 12 contribution, sequences were variably added from chromosomes 1, 4, and 16. Material from chromosomes 1, 4, and 12 was identified by painting in interphase nuclear projections ("blebs") and in micronuclei consistent with the concept that blebs are precursors to micronuclei. The complexity of the mechanisms generating the extra abnormal chromosomes in WDLPS was also attested to by the diversity and, in some cases, intricacy of the patterns of fluorescence. To begin to fathom the function of the extra abnormal chromosomes we examined the amplification of genes, including SAS, MDM2, and GADD153/CHOP, known to be in the region 12q13-14. SAS and MDM2 demonstrated constant co-amplification. GADD153/CHOP, which is critically rearranged in myxoid liposarcoma, was not amplified in WDLPS.

Aged↗

PubMed1991

Nodular regenerative hyperplasia of the liver: an important cause of portal hypertension in non-cirrhotic patients.

In our hospital over the last 10 years a diagnosis of nodular regenerative hyperplasia was made for 13 patients. Sixty-nine percent of these patients had portal hypertension, representing 27% of all our patients with portal hypertension and a non-cirrhotic liver. Nodular regenerative hyperplasia was the second most frequent cause of portal hypertension in patients without cirrhosis. To make the diagnosis, a reticulin staining of a surgical biopsy is most helpful. However, the characteristic derangement of the liver architecture on histology may still be overlooked. In this study a suggestive relation was found between malignant disease (multiple myeloma, chronic myelogenous leukaemia, Leydig cell tumour and Hodgkin's disease), the use of cytotoxic or immunosuppressive drugs and nodular regenerative hyperplasia. Furthermore, a high rate of symptomatic nodular regenerative hyperplasia was observed in patients following kidney transplantation. Liver function abnormalities developed in these patients after a period ranging from 8 months to 3 years of immunosuppressive- or chemotherapy. These liver function abnormalities were, however, usually mild. Since hepatic encephalopathy is not likely to develop in these patients with nodular regenerative hyperplasia a decompressive shunt operation is a good alternative approach, if not the treatment of choice, for the prevention of recurrent variceal haemorrhage.

Adolescent↗

PubMedDate not supplied

Hypochondrogenesis; an additional case.

In a case of hypochondrogenesis, abnormal fat deposits were found in the chondrocytes, by anatomopathological and by ultrastructural examination. In the cultured fibroblast we were unable to demonstrate abnormal lipid loading. Our case could be isolated from other types of lethal congenital chondrodysplasias--especially the lethal type of spondyloepiphyseal dysplasia congenita--by microscopic and ultrastructural investigations.

Achondroplasia↗

PubMedDate not supplied

Immunohistochemical determination of glutathione S-transferases in gastric carcinomas and in adjacent normal gastric epithelium.

Glutathione S-transferases (GSTs) are a family of isoenzymes that play an important role in protecting cells against cytotoxic and carcinogenic agents. The distribution and levels of GST Alpha and Pi in normal and malignant gastric tissue of 34 patients with gastric cancer were examined immunohistochemically. Expression of GST Alpha and Pi was observed in 47 and 100 percent of the tumors, respectively. In normal mucosa both enzyme classes were present in 100 percent of the specimens. Mucous cells showed staining for GST Alpha and Pi in 88 and 97 percent, parietal cells in 93 and 67 percent, and chief cells in 82 and 30 percent, respectively. No correlation was observed between the amount or pattern of GST Alpha or Pi in carcinomas and the clinical and pathological characteristics of the patients. So it can be concluded that both GST Alpha and Pi cannot be considered as prognostic factors for gastric cancer.

Adult↗

PubMedDate not supplied

Glutathione S-transferases in gastric carcinomas and in adjacent normal gastric epithelium: immunohistochemical and biochemical analyses.

Glutathione S-transferases (GSTs) are enzymes involved in the detoxification of xenobiotics and are divided into four subclasses. Alpha, Mu, Pi and Theta. Most human gastrointestinal tumors contain increased amounts of GST Pi. In order to compare data on the expression of GSTs obtained by biochemical as well as immunohistochemical methods, we characterized the presence of GST Alpha and Pi by Western blot analysis and immunohistochemistry in 22 samples of human gastric carcinoma and adjacent non-neoplastic mucosa. Biochemical analyses revealed the presence of GST Alpha and Pi in 95% and 91% of normal tissues and in 82% and 100% of tumor specimens, respectively. Immunohistochemically all cases of normal gastric tissue stained for both GST Alpha and Pi, whereas immunostaining for GST Alpha and Pi was seen in 36% and 100% of the gastric tumor specimens, respectively. No statistically significant correlation however was observed between biochemical and immunohistochemical determination of GST Alpha and Pi both in normal as well as in malignant tissue. The absence of a statistically significant correlation between biochemical and immunohistochemical determination of GST Alpha and Pi implies that a high degree of caution must be taken in interpretating data derived solely from biochemical or immunohistochemical assays.

Adult↗