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Biomedical subjects

C Dimopoulos

Publications and source records attributed to C Dimopoulos.

At least 37 records · Page 2Linked to original sources
PubMed1996

Management of lithiasis in medullary sponge kidneys.

Twenty-four patients with medullary sponge kidneys (MSKs), diagnosed on a recent IVU, and renal lithiasis were treated by extracorporeal shock wave lithotripsy (ESWL). A detailed history regarding frequency of renal colic and urinary tract infection (UTI) was recorded and compared to the post-ESWL frequency of the symptoms. Our results show that the stone clearance rate is similar to that of non-MSK patients but there is a great reduction in the frequency of renal colic and UTI.

Adult↗
PubMed1996

Nitric oxide synthase and xanthine oxidase activities in the spermatic vein of patients with varicocele: a potential role for nitric oxide and peroxynitrite in sperm dysfunction.

PURPOSE: The oxidative and reductive stresses within the varicocele veins were estimated. Nitric oxide synthase and xanthine oxidase activities, as well as nitric oxide, S-nitrosothiols and superoxide release within the spermatic vein in patients with varicocele, and the role of the noxious oxidant peroxynitrite formed from nitric oxide and superoxide in sperm dysfunction were determined. MATERIALS AND METHODS: Whole blood samples were drawn from a peripheral vein and a dilated varicocele vein before ligation. Nitric oxide synthase, xanthine oxidase, nitric oxide and peroxynitrite were measured by novel spectro-fluorophotometric methods. S-nitrosothiols were estimated by a luminol-chemiluminescence method. Serum and red blood cell antioxidant capacity was determined by a chemiluminescence reaction. RESULTS: Serum nitric oxide synthase and xanthine oxidase activities, as well as nitric oxide, peroxynitrite and S-nitrosothiol levels were greater in the spermatic vein compared to the peripheral vein. Serum antioxidant capacity was greater in varicocele veins compared to peripheral veins. In contrast, the antioxidant capacity of red blood cells was less in the varicocele veins, which was consistent with an increased rate of peroxynitrite production. CONCLUSIONS: Our data suggest a high oxidative stress due to the release of nitric oxide synthase and xanthine oxidase within the dilated spermatic vein. The reaction resulted in dramatic formation of nitric oxide, peroxynitrite and S-nitrosothiols, which are biologically active. Formation of peroxynitrite from the reaction of nitric oxide with superoxide could be a causative factor for impaired sperm function in patients with varicocele.

Humans↗
PubMed1995

Evaluation of overexpression of p53 tumor suppressor protein in superficial and invasive transitional cell bladder cancer: comparison with DNA ploidy.

OBJECTIVES: p53 tumor suppressor gene is considered to play a significant role in carcinogenesis. Mutations in the p53 are the most frequent genetic abnormalities encountered in human malignancies. Our aim was to investigate the expression of p53 oncoprotein in superficial and invasive transitional cell bladder cancer (TCC) as well as its correlation with established prognostic factors, such as histologic grade, tumor stage, DNA content, and survival. METHODS: Forty-five patients with superficial TCC (Ta-T1) and 42 with invasive TCC (T2-T4) were included in our study. Material from transurethral biopsy was examined using an immunohistochemical method and the monoclonal antibody Pab 1801. RESULTS: p53 tumor suppressor protein was overexpressed in 48.3% of TCC cases and more frequently in invasive than superficial TCCs (P = 0.03) and undetectable in the tumor adjacent to normal tissue. p53 positivity was related to the degree of differentiation and with the stage of the disease of invasive TCCs (P = 0.03 and P = 0.004, respectively), whereas no statistical significance was documented for superficial TCCs. Moreover, p53 overexpression demonstrated a statistical significance with DNA ploidy in superficial Ta-T1 tumors (P = 0.04) and was suggestive in invasive T2-T4 tumors (P = 0.08). There was no correlation of recurrence related to p53-positive superficial tumors (P = 0.29). Patients with p53-positive invasive TCCs showed statistically significant worse survival (P = 0.007), but in multivariate analysis, p53 positivity is not independently related to poor overall survival (P = 0.30). When we combined ploidy and p53 status, we realized that the subset of patients with aneuploidy and p53 positivity had the worst prognosis (P = 0.008). CONCLUSIONS: The results suggest the involvement of p53 protein as a late event in bladder carcinogenesis. p53 does not seem to be a prognostic marker for recurrences of superficial tumors and is not independently related to survival. The aneuploidy of tumors correlates with the p53 positivity in bladder cancer. The combined expression of aneuploidy and p53 positivity in invasive tumors has strong association with the survival of patients.

Adult↗
PubMed1995

N-butyl-2-cyanoacrylate (Histoacryl) plus sclerotherapy versus sclerotherapy alone in the treatment of bleeding esophageal varices: a randomized prospective study.

BACKGROUND AND STUDY AIMS: N-2-cyanoacrylate (Histoacryl) and endoscopic sclerotherapy with polidocanol have both been reported to control variceal bleeding. The aim of the present study was to compare the effectiveness of the combination of Histoacryl and endoscopic sclerotherapy with polidocanol in the management of these patients regarding early rebleeding and hospital mortality rates. PATIENTS AND METHODS: One hundred twenty-six consecutive patients with variceal hemorrhage treated with injection therapy between March 1990 and July 1993 were included in this randomized prospective study. Sixty-seven patients (Group A) were treated with Histoacryl and conventional sclerotherapy with polidocanol, and 59 patients (Group B) were treated with conventional sclerotherapy with polidocanol alone. Histoacryl was injected intravariceally during the first session in the Group A patients. RESULTS: A significantly lower bleeding recurrence rate was found in Group A patients who presented with active bleeding at the first treatment session (Group A: 2 of 20, Group B: 8 of 18, p < 0.05). The hospital mortality was also significantly lower in these patients (Group A: 3 of 21, Group B: 9 of 18, p < 0.05). CONCLUSIONS: The combination of Histoacryl with conventional sclerotherapy with polidocanol in patients with esophageal bleeding who present with active bleeding, at the initial injection therapy, can improve the results of endoscopic management.

Adult↗
PubMed1995

Epithelial differentiation antigens and epidermal growth factor receptors in transitional cell bladder carcinoma: correlation with prognosis.

Epithelial differentiation antigens have been correlated with morphologic differentiation of neoplastic urothelium. Moreover, epidermal growth factor, which is a polypeptide regulating growth and differentiation of normal and neoplastic cells, is found in high concentrations in the urine while its receptors (EGFR) have been identified in bladder tumors. The aim of this study was to investigate the immunohistochemical expression of cytokeratin, epithelial membrane antigen (EMA), CEA and EGFR in transitional cell bladder carcinomas (TCC) and to define any correlation of their expression with tumor grade, stage and patient survival. Twenty-four biopsy specimens obtained from patients with TCC were studied retrospectively. There were 23 men and 1 woman with a mean follow-up of 64 months. Eight biopsy specimens, which represented tumor recurrences of 4 patients, were also included in our material. The immunohistochemical avidin-biotin complex method was performed on paraffin sections for the detection of cytokeratin and EGFR with monoclonal antibodies as well as CEA with a polyclonal antibody. Cytokeratin was detected in 83.5% of the TCC, EMA in 62% and CEA in 70%. The expression of the epithelial differentiation antigens in TCCs was heterogenous, showing an increased incidence in high-grade and high-stage TCC. The CEA expression in TCC demonstrated a statistically significant correlation with patient survival (p < 0.02). EGFR was detected in 50% of the TCC. Although not statistically significant, a trend was found for a higher percentage of EGFR detection in high-grade TCC. EGFR expression was significantly associated with tumor stage and patient survival (p < 0.01 and p < 0.04, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Clinical implication of neuroendocrine differentiation in prostatic adenocarcinomas.

Specimens from 75 cases of prostatic adenocarcinoma of different M.D. Anderson degrees of malignancy were stained immunohistochemically for neuron-specific enolase (NSE), prostatic specific antigen (PSA) and prostatic acid phosphatase (PAP). None of these tumors presented on hematoxylineosin sections any features suggesting neuroendocrine differentiation; nevertheless, 18.7% of the tumors were at least focally NSE positive. Because of the synchronous antigenic expression of the NSE-positive cells to PSA and PAP, the authors suggest that prostatic exocrine and neuroendocrine cells derive from a common precursor stem cell. The possibility of a more aggressive biological behavior of these tumors in comparison to the conventional carcinomas is discussed. The probable clinical necessity for a combined therapeutic approach is also investigated.

Acid Phosphatase↗
PubMed1995

T-lymphocyte subsets in the peripheral blood of patients with renal cell carcinoma.

We analyzed the phenotypic distribution of the major T-lymphocyte subsets in the peripheral blood of 22 renal cell carcinoma patients before and after nephrectomy. We also compared these distributions to those of healthy controls and related them to tumor spread. The lymphocyte subsets were analyzed by means of flow cytometry. The CD4+ subset was the only one which was significantly decreased (x +/- SD: 36.2 +/- 6.4 vs 41.4 +/- 2.2 in healthy controls, P < 0.05), this contributing to a significant decrease in the CD4/CD8 ration (x +/- SD: 102 +/- 0.56 vs 1.42 +/- 0.28, P < 0.05). The decrease was more apparent with advanced stage. Helper cell activity increased significantly after nephrectomy in the higher stage patients (x +/- SD: 41.1 +/- 4.6 vs 36.4 +/-3.1 and 38.2 +/- 3.9 vs 30.1 +/- 4.2 for stage T3 and T4 patients respectively). Knowledge of peripheral blood lymphocyte patterns that correlate with various tumor stages and therapies could provide information in host-tumor relationship and predict the clinical outcome and response to therapy.

Adult↗
PubMed1995

Extracorporeal shock wave lithotripsy in 5 patients with aortic aneurysm.

PURPOSE: The safety and efficacy of extracorporeal shock wave lithotripsy (ESWL*) in patients with an aortic aneurysm were assessed. MATERIALS AND METHODS: Five patients with an aortic aneurysm and symptomatic renal (4) or upper ureteral (1) lithiasis underwent ESWL with either an HM3 or HM4 lithotriptor. RESULTS: The procedure was well tolerated in all patients. The stone was fragmented completely in the 4 patients with renal lithiasis, while 1 with ureteral lithiasis also required ureteroscopic extraction of the stone fragments. CONCLUSIONS: For patients with symptomatic renal stones and an aortic aneurysm ESWL may be the treatment of choice.

Aged↗
PubMed1995

Angiomyolipoma of the left ureterovesical junction associated with ipsilateral renal agenesis.

To our knowledge we report the first case of retroperitoneal angiomyolipoma located at the left ureterovesical junction associated with ipsilateral renal agenesis. Radiologically, the mass had the characteristics of a cystic soft tissue tumor. Final diagnosis was determined by histopathological examination, which revealed the specific characteristics of angiomyolipoma. The tumor is theorized to be a result of developmental malformation of fetal mesenchymal elements along the ureteral bud during fetal development since it was associated with ipsilateral renal agenesis.

Adult↗
PubMed1995

[Fournier's gangrene: etiology, treatment, and complications].

We report our experience in the treatment of Fournier's gangrene. Ten male patients suffering from necrotising fasciitis of the genitalia were treated by extensive surgical debridement and broad spectrum antibiotic administration. Four were alcoholic and six diabetic. The possible cause was perirectal abscess in 3 cases, urethral stricture in two, traumatic urethral catheter insertion in two, epidydimo-orchitis in one and finally herniorraphy in another case. An average of 2.3 operations was required per patient and the average hospital stay was 38.1 days. Three of them underwent bilateral orchidectomy, two colostomy and a suprapubic catheter was inserted in four cases. Four patients developed acute renal failure and three adult respiratory distress syndrome. Three patients died. Reconstruction using skin flaps was necessary in 4 patients. We conclude that Fournier's gangrene is a true urologic emergency, potential lethal, which requires aggressive antibiotic and surgical treatment.

Adult↗
PubMed1994

Neoadjuvant cisplatin and interferon-alpha 2B in the treatment and organ preservation of penile carcinoma.

We investigated the antitumor activity and toxicity of cisplatin and interferon-alpha 2B as the primary treatment of penile carcinoma. A total of 13 consecutive patients with nonmetastatic, histologically confirmed invasive squamous cell carcinoma of the penis underwent treatment consisting of 20 mg./m.2 cisplatin intravenously and 5 x 10(6) mu./m.2 interferon-alpha 2B subcutaneously daily for 5 consecutive days. An equivalent dose of interferon was then administered subcutaneously every 2 days for 3 weeks and the regimen was repeated at 28-day intervals. Of 12 evaluable patients 9 responded: 4 achieved a pathologically confirmed complete remission of 38+, 21+, 10 and 7 months in duration (2 with relapse were treated with local therapy and remain with no evidence of disease), and 5 achieved a partial response, underwent surgical removal of residual disease and remained disease-free for 14+ to 24+ months. The most significant toxicities were anemia in 5 patients and reversible renal impairment in 3 but no patient had neutropenic fever or required platelet transfusion. We conclude that primary treatment with cisplatin and interferon-alpha 2B induced responses in 75% of 12 patients with penile carcinoma and allowed for a less radical operation than originally scheduled. A larger number of patients and longer followup will be required to confirm these encouraging preliminary results.

Adult↗
PubMed1994

Influence of digital examination, cystoscopy, transrectal ultrasonography and needle biopsy on the concentration of prostate-specific antigen.

The influence of various prostatic manipulations, including digital rectal examination, cystoscopy, transrectal ultrasonography and transrectal needle biopsy, on the serum prostatic-specific antigen (PSA) levels in 170 men, were examined. We found that digital rectal examination, cystoscopy and transrectal ultrasonography had no significant effect on PSA levels, except for transrectal needle biopsy, which caused an immediate increase of serum PSA in 96.2% of the patients lasting more than 2 weeks in 42.3% of the cases. In conclusion, serum PSA determination after digital rectal examination, after cystoscopy and after transrectal ultrasonography is accurate and reliable. On the other hand, we must wait about 6 weeks after needle biopsy before measuring PSA in the serum of patients with prostatic diseases.

Biopsy, Needle↗
PubMed1994

[Isolated amyloidosis of the ureter. Apropos of a case and review of the literature].

Stenosis of the mid-portion of the right ureter and moderate hydronephrosis of the right kidney was seen on the intravenous pyelography of a 60-year-old patient consulting for sudden onset pain in the right inguinal region. Confirmation was obtained with retrograde urography and abdominal computed tomography. Right nephroureterectomy was performed. The pathology examination revealed characteristic features of amylosis located solely at the narrowing of the ureter. Isolated amylosis of the ureter is rare and difficult to diagnose.

Amyloidosis↗
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↗