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Biomedical subjects

C Dimopoulos

Publications and source records attributed to C Dimopoulos.

At least 55 records · Page 3Linked to original sources
PubMed1992

Silver-binding nucleolar organizer regions in benign and malignant prostatic lesions.

Thirty-six transvesical or transurethral prostatectomy cases were selected from the histopathology files of the Laiko General Hospital. Among the 36 cases, there were 10 with benign prostatic hyperplasia (8 patients having distinct areas of adenosis) and 26 cases of prostatic adenocarcinoma (6 grade I, 13 grades II and III and 7 grade IV carcinomas). From each case, silver-binding nucleolar organizer regions (AgNORs) have been counted in sections of routinely processed paraffin-embedded tissue blocks. The mean AgNOR count per case was calculated. For the cases of prostatic hyperplasia, the mean AgNOR count was found to be 2.95 +/- 0.42, for adenosis 3.45 +/- 0.56, for grade I adenocarcinoma 4.97 +/- 0.74, for grades II and III 7.31 +/- 0.81 and for grade IV adenocarcinomas 11.41 +/- 1.68. This difference in the mean AgNOR count was found to be of statistical significance (p < 0.001) between adenosis and grade I adenocarcinomas and between grade II and III and grade IV adenocarcinomas. It appears that AgNOR counting may prove to be of benefit in differentiating between some benign and malignant prostatic lesions and that it might provide information concerning the biological behavior of prostatic adenocarcinomas.

Adenocarcinoma↗
PubMed1992

A cytologic, ultrastructural and immunocytochemical comparison of tumor cells and cell cultures originating in invasive bladder carcinoma.

Tumor cells and urine-voided cells from patients with invasive bladder carcinoma as well as from healthy patients were examined cytologically, ultrastructurally and immunocytochemically. The ultrastructure of tumor cells showed an abundant, dilated, rough endoplasmic reticulum in the form of membrane-bound vacuoles full of granular to fibrillar material located perinuclearly and/or paranuclearly. Some cells exhibited enlarged modified lysosomes containing sparce flocculent and particulate precipitate. Papanicolaou staining of these cells showed two basophilic cytoplasmic textures, one green glossy-patchy, perinuclearly and/or paranuclearly, well segregated from the other texture of peripheral hematoxylinophilic foamy cytoplasm, comparable to the cytologic features of cell cultures originating in invasive bladder carcinoma. PAS diastase showed double distribution and texture of the perinuclear glycosaminoglycans, a glossy accumulated mass and large granules. Glycosaminoglycan sacs similar to those of cell cultures were also present in tumor-dispersed cells. There was a nonspecific binding of antisera against lysozyme, human chorionic gonadotropin and alpha 1-trypsin in normal and tumor cells. Tumor cells and tissues were positive for alpha 1-chymotrypsin distributed perinuclearly and in large spheres. Normal cells lacked the above characteristics. The results indicate that it is feasible to use the aforementioned characteristics in conjunction with the existing bladder-cytologic criteria for malignancy as markers in urothelial cancer with regard to prognosis of superficial tumors with high malignant potential.

Carcinoma, Transitional Cell↗
PubMed1992

Nucleolar organizer regions in prostatic adenocarcinomas. Comparison with flow cytometric analysis, tumor grade, stage and serum prostate-specific antigen levels.

Twenty-eight cases of prostatic adenocarcinomas have been selected and the mean argyrophil nucleolar organizer region (AgNOR) count for each case was evaluated. Nine of these tumors were of high, 13 of median and 6 of low differentiation. It was found that as the tumors became less differentiated, the AgNOR count increased (p less than 0.001). Stage of the disease, serum prostate-specific antigen (PSA) value, and DNA ploidy of all these cases have been examined as well but no statistically significant correlation among these three parameters and the AgNOR count was found.

Adenocarcinoma↗
PubMed1992

Non functioning adrenocortical carcinoma. A rare case.

Adrenocortical carcinoma is a rare tumor and experience in its diagnosis and treatment is limited. We present a case of non functioning adrenocortical carcinoma in which the pre-operative diagnosis of a kidney tumor had been made and a radical nephrectomy was performed.

Adrenal Cortex Neoplasms↗
PubMed1991

Extracorporeal shockwave lithotripsy or extracorporeal piezoelectric lithotripsy? Comparison of costs and results.

One thousand patients with renal stones up to 3 cm in diameter were divided equally into 2 groups matched for age, sex and stone size. One group was treated on the Dornier HM3 lithotriptor and the other on the EDAP LT01. The results showed that for stones less than 1 cm both lithotriptors were equally effective, with a stone-free rate of 87.5% for the Dornier and 90.4% for the EDAP at 3 months. The success rate fell more steeply for the EDAP machine, however, to become 77.2 and 42.5% respectively as the stone size increased to 3 cm. Treatment time was longer on the EDAP lithotriptor and more sessions were required but patients preferred it to the Dornier. Running costs per patient were higher on the EDAP.

Female↗
PubMed1990

Effect of drugs on crystal adhesion to injured urothelium.

The normal urothelium is covered by a glycosaminoglycan (GAG) layer which acts as a barrier to the adhesion of crystals. Destruction of the GAG layer increases the number of adhered crystals, and it is therefore assumed that it promotes crystal growth and stone formation. Intravesical instillation of pentosanpolysulfate, an exogenous glycosaminoglycan, after destruction of this layer reduces the adhesion of crystals to the urothelium. Intramuscular administration of carbenoxolone sodium following the experimental destruction of the GAG layer increases the rate of healing of the layer and reduces the number of adhered crystals.

Adhesiveness↗
PubMed1990

Prostatic-type epithelium in urinary bladder. Clinical, histologic, and immunohistochemical study.

Six cases of urinary bladder mucosa with prostate-type epithelium were studied clinically, morphologically, and immunohistochemically. All patients were male with an average age of fifty-three years; most presented with painless hematuria. Histologically, two types of lesions were observed, the polypoid located in various sites of the bladder wall and the flat lesion found in the bladder neck. Both lesions shared in common a prostatic-type and transitional surface epithelium while prostatic-type glands were prominent in the polypoid lesion. The prostatic-type epithelium was confirmed immunohistochemically by detection of prostatic specific antigen and prostatic acid phosphatase. Based on specific findings we considered the metaplasia as the most reliable histogenetic aspect.

Acid Phosphatase↗
PubMed1989

Development and validation of a new assay for O6-alkylguanine-DNA-alkyltransferase based on the use of an oligonucleotide substrate, and its application to the measurement of DNA repair activity in extracts of biopsy samples of human urinary bladder mucosa.

A simplified and highly sensitive assay for the determination of O6-alkylguanine-DNA-alkyltransferase has been developed and validated by the analysis of extracts of human urinary bladder mucosa. The new assay involves the use of a synthetic dodecanucleotide containing a single O6-methylguanine residue as substrate for the enzyme. This substrate is 5'-end-labelled with [35S]PO3 and separation of repaired and unrepaired oligonucleotide is achived by immuno-precipitation with polyclonal antibodies specific for O6-methyldeoxyguanosine. Kinetic analysis of the repair of the oligonucleotide by extracts of Escherichia coli and rat liver showed that the reaction is first-order in substrate and enzyme and gave the molecular rate constants 7.5 x 10(6) mol-1 1-1 sec-1 and 8.0 x 10(6) mol-1 1-1 sec-1, respectively. The rate constants for the repair of the corresponding O6-ethylguanine-containing oligonucleotide were 3.0 x 10(5) mol-1 l-1 sec-1 and 3.6 x 10(6) mol-1 l-1 sec-1, respectively. Analysis of extracts of 48 samples of normal or neoplastic human urinary bladder mucosa obtained by transurethral biopsy or at surgery, by the new method or by a method involving use of [3H]-methylated DNA as substrate and HPLC, indicated excellent agreement between the two methods. The mean AGT content of normal urinary bladder mucosa obtained from individuals without diagnosed bladder cancer was 0.181 +/- 0.081 (mean +/- SD) fmol/microgram protein, that of neoplastic samples 0.323 +/- 0.177 fmol/microgram protein and that of normal tissue obtained from patients with bladder cancer 0.183 +/- 0.068 fmol/microgram protein. The new method is convenient, rapid and extremely sensitive (it can readily measure femtomole quantities of enzyme) and should prove useful for studies of the biochemical epidemiology of DNA repair.

Animals↗
PubMed1989

Ureterolithotripsy: report of 1000 cases.

A series of 1000 patients with calculi of the ureter at various levels were treated by ureteroscopy and lithotripsy over a period of 27 months. The overall success rate was 88.8%. Stones in the upper third of the ureter were removed in 15 of 39 patients. Calculi in the middle third were successfully removed in 52 of 102 patients. A success rate of 95.5% was achieved for calculi of the lower ureter. Per-operative complications included 10 ureteric perforations, 4 of which were treated surgically and 6 conservatively. Urography, performed in 520 patients 3 months post-operatively, showed 12 ureteric strictures; 9 of these were treated by insertion of a self-retaining pig-tail catheter and 3 required an operation. Ureterolithotripsy appears to be the method of choice in the management of ureteric calculi.

Adolescent↗
PubMed1989

[Extracorporeal shockwave lithotripsy: our experience in 5,000 cases].

The authors report their experience on 7,500 patients who underwent extracorporeal shock wave lithotripsy (ESWL1). The first 6,800 were treated with the standard Dornier HM-3 lithotripter, while the remaining 700 were treated with the modified HM-3 machine equipped with the new ellipsoid (and the double-shot generator). The authors present the results and conclusions from their experience with 5,000 ESWL treatments which were performed at their Urology Department. An analysis is made on patient age, sex, stone site, duration of sessions, average number of shock waves used, exposure time, number of electrodes per session, retreatments, and results achieved relative to stone size. Furthermore, the authors report on the complications and treatment in special cases; i. e., patients with horseshoe kidneys, solitary kidneys, spinal cord lesions, radiolucent calculi, hemophilia, and staghorn stones. The mean duration of treatment was 37 minutes. The average number of shock waves used was 1,703. The mean radiation exposure time was 1.9 minutes. Two electrodes per session were required in 48% of the patients. Three months following lithotripsy, 72% of the patients were stone-free, 19% had small remaining stone fragments, and 9% had unimportant stone particles.

Adult↗
PubMed1988

Corynebacterium-induced cystitis with mucosal incrustations.

Alkaline-incrusted cystitis is a rare condition that was first described more than 70 years ago. Since then few cases have been reported. To our knowledge, we report the second such case in the literature in which Corynebacterium D2 was considered as the causative factor of incrusted cystitis.

Adult↗
PubMed1988

Methodology, results and complications in 2000 extracorporeal shock wave lithotripsy procedures.

Since the installation of an extracorporeal shock wave lithotriptor (ESWL) unit 12 months ago, 2000 lithotripsy procedures have been performed. Overall, 68.4% of patients were stone-free by the end of the first month. Residual lithiasis (fragments less than 0.5 cm) was seen in 19.7% of patients and significant lithiasis (fragments greater than 0.5 cm) was observed in 10.1%. Complications were obstruction, infection, headache due to the epidural anaesthesia, anuria, renal failure, perirenal haematoma and cardiac arrest. A number of patients required additional operative treatment; this was always endoscopic and no open procedures were performed. Hospitalisation averaged 1 day.

Female↗
PubMed1988

Common characteristics of primary cell cultures originated from invasive urothelial carcinoma.

Ten primary cultures from invasive urothelial carcinomas were studied by light and electron microscopy. In all cultures, cells with accumulations of glycosaminoglycans were observed. Long membrane extensions with accumulations of glycosaminoglycans invaded neighboring cells and formed an extracellular matrix as well. The extracellular matrix inhibited cell proliferation and enhanced tumor nodule formation.

Aged↗
PubMed1988

Morphological and immunohistochemical characteristics of a cell line originated from noninvasive human bladder transitional-cell carcinoma.

A cell line (IG) was derived from a noninvasive transitional cell carcinoma grade II. The cells were propagated in vitro for 9 months, had a low proliferative capacity, formed tumor nodules, and showed four characteristic morphological stages. Primary epithelial-like cells were characterized as stage I; fibroblast-like cells with loss of contact inhibition of growth as stage II; fibroblast-like cells with long cytoplasmic projections, massive glycosaminoglycan content and tumor nodule formation as stage III; and, as stage IV, granulated stellate cells. The cell culture progressed cytologically from well-differentiated stage I to less-differentiated stage IV. The four stages were confirmed and examined by electron microscopy. Immunoreactivity for fibronectin, keratin, epithelial membrane antigen and carcinoembryonic antigen shown by the cell line and the tissue indicates that the cell line represents the original cell population in the tumor. Glycosaminoglycan production by these cells was found to be responsible for the formation of tumor nodules which appeared in culture at the same time as the patient had developed an invasive bladder tumor. Glycosaminoglycans were observed as a massive accumulation intracellularly and extracellularly, as rods or thick slices in layers of adherent vesicles and granules covering the cell culture. Normal bladder epithelial cells and fibroblasts grew in monolayer, showed contact inhibition of growth, were devoid of intracellularly accumulated glycosaminoglycans and produced uniform extracellular matrix different from that of IG cells.

Adult↗