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Biomedical subjects

O Yaman

Publications and source records attributed to O Yaman.

At least 19 recordsLinked to original sources
PubMed1997

Stone disintegration: effect of shock wave projection and electrode age on this parameter in a standard stone model.

Despite the real effectiveness and successful results of shock wave application, the effect of some varying parameters, namely number of shock wave (SW) electrical discharge value (kV), projection of the shock waves and electrode age are still to be evaluated. By using a standard stone model, we evaluated the real effect of the projection of shock waves and electrode age on the degree of stone disintegration. Our results indicated no significant relationship between the kV value and the degree of stone disintegration. However, as the number of SW increased, the rate of disintegration became evident. On the other hand, application of the same number of SW from two different angles revealed more effective disintegration rate on standard stone model. Thus SW number, age of the electrode and the projection of shock waves seemed to be important in the disintegration of the stones.

Electrodes↗
PubMed1997

Preservation of shock-wave-induced renal histologic changes by dermatan sulfate.

OBJECTIVES: To evaluate the protective effects of glycosaminoglycan (GAG) administration on shock-wave-induced renal histologic alterations, an experimental study using dermatan sulfate administration (DS) in rabbits was performed. METHODS: The study included 45 white New Zealand rabbits; 36 were divided into two groups before shock-wave application. Animals in the first group (n = 18) received no specific medication before or after shock-wave treatment; animals in the second group (n = 18) received subcutaneous DS administration for a period of 2 months, beginning 2 weeks before shock-wave application. Following different numbers of shock-wave application (500, 1000, or 1500 shock waves), histopathologic evaluation of treated kidneys was made under light microscopy after 24 hours and 3 months. Nine animals were used for the control group. RESULTS: During 24-hour examination, most of the kidneys in both groups demonstrated varying degrees of histopathologic alterations, depending on the number of shock waves applied. Among the most prominent pathologic features were protein deposition with free erythrocytes in the tubular lumen, glomerular hemorrhage, tubular dilation and degeneration, protein in Bowman's capsule, hyperemia, and mononuclear cell infiltration at the interstitial level. As opposed to the 24-hour evaluation findings, long-term (3-month) follow-up examination revealed histopathologic alterations that decreased but did not totally disappear in animals receiving no DS. Glomerular basement membrane thickening, mononuclear cell infiltration and limited protein deposition in some tubules, together with cortical interstitial fibrosis, were observed to some extent in these animals. On the other hand, no severe histopathologic alteration with normal glomerular basement membrane appearance was noted in animals receiving DS medication. CONCLUSIONS: Our results indicated a long-term favorable protective effect of DS administration on morphologic abnormalities in rabbits undergoing shock-wave treatment. Although tubular alterations persisted to some extent, mononuclear cell infiltration has been limited and the natural appearance of the basement membrane has been well preserved in most of the treated animals.

Animals↗
PubMed1997

Immunohistochemical determination of p53 protein in prostatic cancer and prostatic intraepithelial neoplasms.

A role of genetic alterations in the p53 tumor suppressor gene has been implicated in many types of human malignancies. In this study, we examined the prevalence of immunohistochemically detectable p53 accumulation in prostatic tissues obtained from patients with prostatic adenocarcinoma, benign prostate hyperplasia and prostatic intraepithelial neoplasms. Six of 36 (16.7%) cancer cases and 2 of 11 (18.2%) cases of high-grade prostatic intraepithelial neoplasms showed p53 expression while no nuclear staining was observed in normal and hyperplastic prostatic tissues. Correlation of p53 expression with cancer stage, Gleason score and serum prostate-specific antigen level demonstrated that there was no statistically significant relationship between p53 expression and these clinicopathological parameters. Also, no significant association between p53 expression and prognosis was observed.

Adenocarcinoma↗
PubMed1997

Carcinosarcoma of the prostate. A case report and a possible evidence on the role of hormonal therapy.

A case of prostatic carcinosarcoma is presented with histopathologic and immunohistochemical characteristics. A 70-year-old man presented with a history of anti-androgen (cyproterone acetate) therapy for prostatic adenocarcinoma. Diffuse and strong staining for progesterone receptor was observed in the carcinosarcoma specimen although it was completely negative in the previous adenocarcinoma specimen. It may be speculated that hormonal therapy might have facilitated the selection of a progesterone-dependent subclone of tumor cells with the ability of mesenchymal differentiation and that genetic instability due to p53 inactivation might have played a role in this process.

Adenocarcinoma↗
PubMed1997

Is deep dorsal vein arterialization an alternative surgical approach to treat venogenic impotence?

OBJECTIVE: Several surgical techniques have been applied for the treatment of cavernosal venous leakage, sufficient enough to create erectile dysfunction. In light of the variable success rates, we report our experience with deep dorsal penile vein arterialization for the management of severe cavernosal venous leakage. PATIENTS AND METHODS: Twenty-four impotent patients with venous leakage were treated by the Virag-II type of end-to-end anastomosis of the inferior epigastric artery to the deep dorsal penile vein and ligation of the vein proximally. Diagnostic evaluation included color flow Doppler sonography before and after intracavernous 60 mg papaverine injection and dynamic cavernosometry/ cavernosography, which indicated veno-occlusive dysfunction in 28 patients. Revascularization was technically possible in 24 of the patients, although in 4 anastomosis could not be achieved due to the poor quality of the inferior epigastric artery. RESULTS: Five patients had early occlusion in the immediate postoperative period and 4 had late occlusion within 8 months. Potency was improved initially in 9 (38%) of the 24 patients in whom successful anastomosis had been achieved, with longer term improvement in 6 (25%) of 24 who realized restoration of erectile potency as defined by clinical investigations. The mean follow-up was 24 months (range 3-36 months). CONCLUSION: We believe that anastomosis of the inferior epigastric artery to the deep dorsal penile vein and ligation of the vein proximally in cases of venous leakage results in a low success rate due probably to a pancavernosal alteration in corporal tissue compliance.

Adult↗
PubMed1997

Activity of the enzymes participating in purine metabolism of cancerous and noncancerous human kidney tissues.

In this study, activity of some of the key enzymes participating in purine metabolism was measured in cancerous and noncancerous human kidney tissues from 18 patients with renal cell carcinoma. Twelve cancerous tissues were at stage T1-T2 and 6 tissues were at stage T3-T4. Adenosine deaminase (ADA) and guanase (GUA) activity was increased and xanthine oxidase (XO) activity decreased in cancerous tissues compared to noncancerous ones. No difference was, however, found between 5'-Nucleotidase (5'-NT) activity of the tissues. There were also no statistically meaningful differences between the enzyme activities of the cancerous tissues at stage T1-2 and T3-4. Results suggest that the changes observed in the activity of the enzymes participating in purine metabolism result from accelerated DNA turnover in the cancerous tissues and cells, and these changes might provide selective advantage, possibly by causing acceleration of salvage pathway activity, to the cancer cells to grow and develop more rapidly.

5'-Nucleotidase↗
PubMed1996

Effects of extracorporeal shock wave lithotripsy on stone forming risk factors.

It has been reported in some definite studies that ESWL causes transient deterioration in renal haemodynamics and function. Again certain parameters in blood and urine have been used in order to assess this functional deterioration and different results are reported. In our present study we aimed to describe the adverse effects of shock waves on the excretion of urinary metabolites such as electrolytes, oxalate and citrate. Evaluation of our results in 30 patients revealed that although exposure to shock waves during ESWL for symptomatic renal calculi causes a slight increase in the urinary level of metabolites, all of these changes remained in normal range and no statistically significant changes in the urinary level of the aforementioned parameters could be demonstrated.

Adolescent↗
PubMed1996

Serum neuron specific enolase: can it be a tumour marker for renal cell carcinoma?

Neuron specific enolase (NSE) is an isoenzyme of the glycolytic enzyme enolase. It is not only a marker for all types of neurons but also for all neuroendocrine or paraneuronal cells and various malignant tumours, even of non-neuroendocrine types. We had studied serum NSE in 25 consecutive patients with renal cell carcinoma (RCC). The study included 10 stage I, 3 stage II, 3 stage III-B and 9 stage IV-B patients. Both pretreatment and posttreatment levels were evaluated. Regardless of stage, overall we observed elevated levels of NSE in 80% (20/25) at diagnosis. After the appropriate treatment, according to the stage, there had been a statistically significant (p < 0.05) decrease in the serum levels in all stage I, II and III-B patients. The posttreatment values were not available for stage IV-B patients because they did not come for follow-up. The preliminary results of our study revealed that serum NSE may be considered as a useful marker in the evaluation and surveillance of RCC.

Adult↗
PubMed1996

Evaluation and surgical treatment of patients with penile curvature.

In patients with adult penile curvatures the aim of treatment is to have a penis straight enough and firm enough to allow satisfactory sexual function. Several operative approaches have been used to correct this condition. Herein, we describe our experience with the evaluation and surgical treatment of 37 patients with penile curvature. When we have decided on surgery, we either preferred to elongate the ventral corpora cavernosa by interposition of a piece of dura mater (2 patients) or in most cases (the remaining 35 patients) only excised wedges of tunica albuginea at the arcs of the maximum curvature located with artificial erection (Nesbit's operation). In conclusion, our results showed that Nesbit's operation is a versatile procedure that proved to be useful for correction of penile curvatures in patients with Peyronie's disease. However, further studies and clinical trials are needed to determine if the dura mater is an alternative in the treatment of penile curvatures due to congenital aetiology.

Adolescent↗
PubMed1996

Renal liposarcoma of the sinus renalis.

We report on 42-month follow-up of a case of renal liposarcoma of the sinus renalis with tumour-free survival. It is a rare condition and occurs generally in the 4th and 6th decades of life. Renal liposarcomas are clinically asymptomatic for a long period of time. Symptoms develop only when the tumours become large enough, as in our case. For the differential diagnosis of renal liposarcoma we performed intravenous urography, computerized tomography and colour flow Doppler ultrasonography. After these diagnostic evaluations the patient underwent right radical nephrectomy. Complete surgical resection was performed. Final diagnosis was made by pathological examination. Because of the poor results of either chemotherapy or radiotherapy, we conclude that 42 months of tumour-free survival is related to complete surgical resection with negative surgical margins.

Humans↗
PubMed1996

Leucine aminopeptidase enzymuria: quantification of renal tubular damage following extracorporeal shock wave lithotripsy.

To evaluate the extent of renal parenchymal injury following high energy shock wave (HESW) application we measured the urine levels of two renal tubular brush border enzymes: leucine aminopeptidase (LAP) and gamma-glutamyltranspeptidase (GGT) the day before, 24 hours and 7 days after extracorporeal shock wave lithotripsy (ESWL) in 23 patients. All patients had caliceal stones and were treated with a Dornier MPL 9000 lithotriptor under sedoanalgesia. Creatinine concentration of each sample together with total shock wave effect (TSWE) values were also assessed and comparatively evaluated with enzymuria levels. Our results indicated a statistically significant rise in urinary excretion of both enzymes after 24 hours following lithotripsy (p < 0.05). All these values returned to normal limits within 7 days after ESWL (p > 0.05). Transient tubular damage due to HESW was found to be related to TSWE values assessed in our group.

Adolescent↗
PubMed1996

Staging with computed tomography, transrectal ultrasonography and transurethral resection of bladder tumour: comparison with final pathological stage in invasive bladder carcinoma.

OBJECTIVE: To assess the accuracy of clinical staging methods in patients with locally advanced bladder cancer. PATIENTS AND METHODS: Sixty-five patients with invasive bladder cancer primarily staged using transrectal ultrasonography (TRUS), computed tomography (CT) and transurethral resection of the bladder tumour (TURBT) were compared with the final pathological stage determined after radical cystectomy. RESULTS: Accurate staging was obtained by TRUS, CT and TURBT in 40, 35 and 46% of the patients, respectively. The rank correlation between primary clinical stage and final pathological stages was significant by all three methods, but not close. CONCLUSIONS: The results of this study raise doubts about the assumed benefit of TRUS and CT in the clinical staging of invasive bladder tumours. These methods did not improve the findings obtained by TURBT alone.

Adult↗
PubMed1996

Protective effect of verapamil on renal tissue during shockwave application in rabbit model.

Although extracorporeal shockwave lithotripsy (SWL) is the treatment of choice for symptomatic urinary calculi, it has been shown in number of studies that adverse effects of high-energy shockwaves may be encountered in short- and long-term follow-up. To evaluate the possible protective effect of verapamil administration on renal tissue, both magnetic resonance imaging (MRI) and histopathologic examination were performed after SWL in rabbits. Thirty-five animals were divided into three groups. The 15 animals in the first group were fed verapamil (0.1 mg/kg) for 3 days. Another 15 animals received no medication but underwent SWL, and the remaining 5 animals received anesthesia alone (sham group). The animals were then subdivided into three groups according to the shockwave number applied (1000, 15,000, or 2000) and the aforementioned evaluations were performed 24 hours and 3 months after the procedure. We found prominent histopathologic alterations in animals not receiving any medication before SWL. Persistence of these pathologic alterations during 3 months of follow-up indicated the importance of preservation of renal architecture during high-energy shockwave application. On the other hand, animals under verapamil medication prior to SWL demonstrated only a limited degree of histopathologic alteration. Demonstration of a normal histologic pattern after 3 months supported the preservation of tissue structure by such medication. No significant histopathologic alteration could be observed in the sham-group animals, as expected. Our study demonstrates that verapamil is protective against shockwave-induced renal tubular damage. Such medications may be useful to avoid the proven histopathologic and functional side effects of high-energy shockwaves.

Animals↗
PubMed1996

Stone recurrence after shockwave lithotripsy: possible enhanced crystal deposition in traumatized tissue in rabbit model.

To evaluate the possible traumatizing effect of high-energy shockwaves (HESW) on new stone formation as indicated by crystal deposition in the renal parenchyma, we performed an experimental study in 50 rabbits. During severe oxaluria induced by continuous ethylene glycol (0.75%) administration, animals in the first group (N = 15) received 500 to 1500 shockwaves. Animals in the second group (N = 15) underwent no specific therapy apart from ethylene glycol administration. In a third group of animals (N = 15), only shockwave administration was applied. Sham group animals constituted the last group in our study (N = 5). Three months after shockwave application, tissue sections obtained from treated and untreated kidneys were evaluated histopathologically under light and transmission electron microscopy (TEM) for the presence and degree of crystal deposition in the cortical parenchymal region subjected to HESW. Crystal deposition was evident in the intercellular region and intratubular parts of the parenchyma in animals subjected to HESW application, especially in those receiving relatively high (1000 or 1500) numbers of shockwaves. On the other hand, no crystal formation and deposition was detectable in animals undergoing only ethylene glycol therapy or shockwave administration alone. Sham group animals demonstrated no significant renal histopathology. The traumatic effects of HESW should be evaluated as a factor in new stone formation after SWL.

Animals↗
PubMed1996

Effects of extracorporeal shockwave lithotripsy on urinary concentration of epidermal growth factor.

In a prospective study, we tried to determine whether extracorporeal shockwave lithotripsy (SWL) has any effect on urinary epidermal growth factor (EGF) concentrations and to investigate whether EGF can be used as a marker for detecting shockwave-induced impairment of distal tubular cells. A total of 12 patients with renal pelvic or caliceal stones < or = 2 cm undergoing anesthesia-free SWL without ancillary measures and a control group of 10 patients without any urologic symptoms were included in this study. The urinary concentrations of EGF were measured by radioimmunoassay before and 4 hours, 24 hours, and 7 days after SWL. Relative urinary EGF concentrations were expressed as the ratio of EGF to creatinine (ng/mL creatinine). The mean urinary EGF concentration (mean +/- standard error) in control subjects and patients with renal pelvic or caliceal stones before SWL was 23.90 +/- 3.15 ng/mL creatinine and 22.18 +/- 6.85 ng/mL creatinine, respectively (p > 0.05). In patients with stones, we found a decrease in urinary EGF concentration 4 hours, 24 hours, and 7 days after SWL. Indeed, 7 days after SWL, the EGF concentration was on average half of the original value, a biologically significant, although not statistically significant, decrease.

Adult↗
PubMed1996

Effect of total and ionized calcium levels of seminal fluid on sperm motility.

Total and ionized calcium (Ca2+) levels of seminal fluid were assessed in 75 semen samples obtained from infertile patients and fertile patients referred to our clinic with different complaints. Patients who showed only motility disorders on sperm analysis were include into the study program. Forty-five patients showing hypomotility (motility < 60%) and 30 patients with normal motility (motility > or = 60%) on sperm analysis were evaluated comparatively. No significant difference was observed in the seminal fluid concentration of total calcium, regardless of spermatozoa motility immediately after ejaculation. However, the seminal fluid of men with hypomotility exhibited a significantly lower Ca2+ concentration (p < 0.05) when compared with that of men with normal motility. A significant difference was observed in the seminal fluid Ca2+/total calcium rate (p < 0.05) when compared with that of men with normal motility. Further, spermatozoa from men with hypomotility exhibited both a significantly lower progression rate and sperm count. Our study suggests a direct relationship between Ca2+ and sperm motility.

Adult↗