Biomedical subjects

A Akdaş

Publications and source records attributed to A Akdaş.

At least 19 recordsLinked to original sources

PubMed2000

Use of double J stent in a case of spontaneous ureteral extravasation of urine.

OBJECTIVES: Although there are numerous case reports of spontaneous rupture of the collecting system, especially including the calyceal fornix or the renal pelvis, spontaneous rupture of the ureter is a rare condition. METHODS: Herein, we present a case of a patient who suffered symptoms of acute abdomen due to rupture of the proximal ureter. Extensive assessment revealed no etiological factor as to the extravasation. RESULTS/CONCLUSIONS: The condition was managed conservatively by insertion of a double-J catheter. The double-J ureteral stent was removed on the first postoperative month under local anesthesia uneventfully. One year after the spontaneous ureteral extravasation, the patient remained without clinical problems. The diagnosis, pathogenesis and complications of this unusual condition are reviewed.

Equipment Design↗

PubMed1999

Alteration of epidermal growth factor receptor expression following ischaemia of renal tissue.

This study was aimed to investigate Epidermal Growth Factor Receptor (EGF-R) expression after ischaemic injury in renal tissue and the effects of calcium channel blockers in the prevention of damage due to ischaemic insult. Simple nephrectomy was performed in a group of Sprague-Dawley rats, and kidneys were grouped according to cold ischaemia time (1, 6, 12, 24 and 48 hours, respectively) and to the type of calcium channel blockers (diltiazem and verapamil) used. EGF-R expression status was investigated in each group by immunohistochemistry on paraffin sections. Overall expression of EGF-receptor was detected in 8 (22.8%) kidneys. In terms of localization of EGF-receptor expression cortical tubular staining was detected in 8 (100%) kidneys, medullar tubular staining in (62.5%) kidneys and glomerular mesangial staining in 5 (62.5%) kidneys. There was no difference between various ischaemia times and different calcium channel blockers used. It has been concluded that hypoxia and cold ischaemia causes widespread down-regulation of EGF-receptor expression in renal tissue regardless of treatment with calcium channel blockers.

Animals↗

PubMed1999

Clinical significance of nuclear p53 protein accumulation in bladder cancer.

OBJECTIVES: To investigate the correlation of nuclear p53 accumulation with disease outcome in a cohort of patients with transitional cell carcinoma of the bladder. METHODS: A total of 90 patients (11 female, 79 male) with transitional cell carcinoma of the bladder were included in this study. Tumour samples from the primary tumour were analysed by immunohistochemistry for nuclear accumulation of p53 protein. Outcome of each patient was recorded and investigated for a possible relation with p53 status. RESULTS: Nuclear p53 deposition was determined in 22 specimens. The nuclear p53 deposition was seen in less than 20% of the nuclei examined in 13 and more than 20% in 9 cases. No stromal staining was observed. Nuclear p53 deposition was present in 15.2% (7/46) of grade 2 tumours, and 34% (15/44) of grade 3 tumours (p=0.037). Stage distribution revealed 15.5% (5/33) positivity in stage pTa, 25.8% (8/31) in pT1 and 34% (9/26) in stage pT2-3 tumours. Tumours with p53 nuclear accumulation had a higher rate of recurrence and progression and shorter survival. CONCLUSION: Results of the current study indicate p53 as an important factor in determination of biological behaviour of bladder cancer.

Carcinoma, Transitional Cell↗

PubMed1999

Prognostic significance of p53 protein accumulation in stage pT1 transitional cell carcinoma of the bladder.

OBJECTIVE: Mutations in the tumour suppressor gene p53 results in the production of a mutant type, dysfunctional p53 protein which can readily be detected in the cell nucleus by immunohistochemical staining. This study aims to investigate the association of nuclear p53 protein accumulation with the clinical outcome of stage pT1 transitional cell carcinoma of the bladder which is renowned for high rates of recurrence and progression. METHODS: TUR samples of the tumours from fifty-two patients with primary stage T1 bladder cancer were analyzed immunohistochemically using the standard avidin-biotin peroxidase method for nuclear p53 accumulation. Status of p53 immunostaining was correlated with tumour recurrence, disease progression and three-year survival of each patient. RESULTS: The rate of tumour recurrence in pT1 bladder cancer was 36% in patients with tumours stained negatively for p53 protein and 78% in patients with tumours stained positively for p53 protein. Disease progression was seen in 15% of p53 (-) patients and in 56% of p53 (+) patients. CONCLUSIONS: In stage pT1 bladder tumours p53 nuclear accumulation indicates higher rates of tumour recurrence and disease progression. Accordingly, in patients who have pT1 bladder tumours with nuclear p53 accumulation, institution of more aggressive therapy should be considered and early radical therapeutic modalities should be offered to these patients.

Adult↗

PubMed1998

Bcl-2 and p53 overexpression as associated risk factors in transitional cell carcinoma of the bladder.

Bcl-2 and p53 genes are implicated in cell cycle regulation with roles on programmed cell death. Consequently, presence of Bcl-2 and nuclear accumulation of p53 were proposed to confer a growth advantage tumour cells. We have investigated their role as prognostic factors in fresh tumour samples from a cohort of twenty patients with transitional cell carcinoma of the bladder by immunohistochemical analysis in paired specimens. Expression of Bcl-2 was observed in 11 cases (69%) and nuclear p53 accumulation in 9 (45%). In the presence of Bcl-2 protein expression, tumours showed a slightly higher rate of recurrence (55% vs. 40%) and significantly more progression (36% vs. 0%). Recurrence and progression rates were not significantly different in tumours with and without nuclear p53 overexpression (recurrence rates 56% vs. 55% and progression rates 33% vs. 27%, respectively). Grade and stage appeared as important prognosticators since 75% of grade 3 tumours showed recurrence and 50% progressed in contrast to 44% and 13%, respectively, of grades 1 and 2 tumours. Similarly, 50% of Ta-T1 tumours recurred and 20% progressed, while these rates were 75% and 75% for T2-T3 tumours. Also, expression of Bcl-2 and nuclear accumulation of p53 correlated with grade. In grade 3 tumours, 75% showed nuclear p53 overexpression and 80% cytoplasmic Bcl-2 protein. These figures were 25% and 64% for grades 1 and 2 tumours. In conclusion, Bcl-2 protein expression in transitional cell carcinoma appears to be associated with a poorer prognosis and together with nuclear p53 overexpression they are associated with tumour de-differentiation.

Carcinoma, Transitional Cell↗

PubMed1998

Impact of the expression of epidermal growth factor, transforming growth factor alpha, and epidermal growth factor receptor on the prognosis of superficial bladder cancer.

OBJECTIVES: To investigate the correlation of epidermal growth factor receptor (EGFR) expression and its ligands EGF and transforming growth factor-alpha (TGF-alpha) with disease outcome in a cohort of patients with superficial bladder cancer. METHODS: Tumor samples of 21 patients with transitional cell carcinoma of the bladder were analyzed by immunohistochemistry for expression of EGFR, EGF, and TGF-alpha. Disease-related events were recorded during a routine clinical follow-up and analyzed for possible correlation with the expression status of the above-mentioned proteins. RESULTS: All Stage pT1 transitional cell carcinomas expressed EGFR, and 10 of 21 (48%) tumors showed focal areas of strong EGF and/or TGF-alpha expression. Of these, 80% with EGF positivity (8 of 10) had recurrences, whereas only 9% of patients without EGF staining (1 of 11) did so. The same pattern was observed with TGF-alpha. A strong association was confirmed between EGF/TGF-alpha positivity and tumor recurrence (P <0.005). We also found that EGF and TGF-alpha were expressed in stroma and/or around the vessels of tumor tissue in 48% and 38% of the tumors, respectively. No association was found between the recurrence rate/vascular invasion and the stromal/vascular wall expression of the growth factors. CONCLUSIONS: Expression of EGF and TGF-alpha is correlated with tumor recurrence. Also, there is the ability of vessel walls to express EGF and TGF-alpha in superficial bladder cancer. Further clarification of the impact of this expression on angioinvasion of tumor cells may be helpful in understanding the nature of local invasion and metastasis.

Adult↗

PubMed1998

The role of in vitro chemosensitivity tests to predict the clinical efficacy of antineoplastic agents in genito-urinary tumors.

OBJECTIVE: To develop an in vitro screening system to predict the response to treatment of common malignancies of the genito-urinary tract. MATERIAL AND METHODS: Flow cytometric analysis and cytotoxicity assays (trypan blue and lactic dehydrogenase colorimetric tests) were performed on hormone resistant prostate cancer cell line PC-3 and primary transitional cell carcinoma samples treated with different antineoplastic agents and their combinations. Apoptosis induced by different agents was also investigated by previously established criteria. RESULTS: There were 9 bladder tumors (47.4%) in the study group that displayed drug resistance to at least one antineoplastic agent. When the drugs were examined individually, there was resistance to cis-platinum in 3 patients (15.8%), methotrexate in 6 (31.6%), vinblastine in 7 (36.8%), epirubicin in 2 and adriamycin in 2 patients (10.5%). Stratification of patients according to the stage of the tumor revealed statistically significant difference between the superficial and invasive tumors in terms of drug resistance (p < 0.05). In prostate cancer cell line vinblastine treatment resulted in a significant increase in S phase fraction. Percent cytotoxicity by trypan blue exclusion test was 26.1% and was significantly higher than the control group (8.7%, p < 0.002). Also, an increase in apoptotic index after the treatment was observed (44.4% and 12.1%, respectively; p < 0.0001). CONCLUSION: Both toxicity assays showed a very good correlation (p < 0.005) and can be used to evaluate the effects of different antineoplastic agents on individual tumors.

Adult↗

PubMed1998

Role of apoptosis in testicular tissue damage caused by varicocele.

OBJECTIVE: Histomorphological changes reported in patients with varicocele (so-called stress pattern) have some degree of resemblance to the ones observed during apoptosis of various cell types due to a variety of reasons. In order to further clarify a possible role of apoptosis in impaired spermatogenetic activity associated with varicocele, we have investigated the presence of this specific type of cell death in testicular tissue. MATERIAL AND METHODS: Surgical specimens were obtained after the completion of ligation and division of the spermatic vein(s) in patients with varicocele associated with infertility and testicular tissue obtained by scrotal orchiectomy for hormonal ablation treatment in prostate cancer patients served as the control group. Terminal deoxynucleotidyl transferase end labeling (TUNEL) technique was utilized in paraffin-embedded tissue specimens to demonstrate the presence of apoptosis. RESULTS: Data obtained from 29 samples (varicocele, 24 patients; control, 5 patients) revealed that apoptosis was quite rare in testicular tissue of control group. Mean percentage of apoptotic cells per high power field (x400 magnification) was 2% for the control group and 14.7% for varicocele patients. CONCLUSION: In light of our data, it appears that apoptosis may have a significant role in spermatogenetic dysfunction associated with varicocele.

Adolescent↗

PubMed1997

The impact of prostate-specific antigen, its density and the Gleason score in the prediction of extracapsular disease in prostate carcinoma.

OBJECTIVE: To evaluate the effectiveness of serum prostate-specific antigen (PSA). PSA density (PSAD), the preoperative Gleason score of transrectal-ultrasonography (TRUS)-guided needle biopsies and the Gleason score of the final histological examination in predicting extracapsular disease in prostate cancer (PCa). MATERIAL AND METHODS: We retrospectively analyzed 32 patients who underwent radical retropubic prostatectomy as the primary treatment for their clinically localized disease. RESULTS: Extracapsular extension was found in 21 patients. In a comparison of different cutoff levels, the best positive predictive values were found for PSA of 20 ng/ml, PSAD of 0.2 and 0.3, a Gleason score of TRUS-guided biopsies of 5 and one of the prostatectomy specimens of 7 with 100, 80 (both), 74 and 95%, respectively, A PSA value higher than 20 ng/ml and a preoperative Gleason score of 7 or higher predicted extracapsular disease with specificity rates of 100 and 91%, respectively. It was noteworthy that there was a statistically significant undergrading in the extracapsular group in the Gleason scores of TRUS-guided biopsies compared to the prostatectomy specimens. CONCLUSION: PSA levels above 20 ng/ ml and/or Gleason scores of 7 or higher in TRUS-guided biopsies are strong indicators of extracapsular extension of PCa.

Aged↗

PubMed1997

Reactive oxygen species production by the spermatozoa of patients with idiopathic infertility: relationship to seminal plasma antioxidants.

PURPOSE: We attempted to determine reactive oxygen species production by the spermatozoa of patients with idiopathic infertility and healthy donors, and observe whether increased production was due to decreased seminal plasma reactive oxygen species scavengers. MATERIALS AND METHODS: Reactive oxygen species production by spermatozoa and seminal plasma antioxidants was assayed in 18 patients with idiopathic infertility and 10 controls. Reactive oxygen species formation and seminal plasma antioxidants were measured by luminol and lucigenin dependent chemoluminescence, and enzymatic methods, respectively. RESULTS: Higher reactive oxygen species production was observed in 16 of the 18 patients (88.8%, p < 0.0001 versus controls). Seminal plasma superoxide dismutase, catalase, glutathione peroxidase and total sulfhydryl group levels in infertile patients were significantly lower than in controls. CONCLUSIONS: Decreased seminal plasma antioxidant activity and increased reactive oxygen species production can be responsible for idiopathic male infertility.

Acridines↗

PubMed1996

Spontaneous fracture of indwelling ureteral stents in patients treated with extracorporeal shock wave lithotripsy: two case reports.

Placement of indwelling ureteral stents adjunctive to ESWL treatment has been a widespread practice. We herein present two cases of spontaneous breakage of double pigtail ureteral stents and their management. Prevention of this complication may be possible by careful examination of the stents prior to insertion, by following the instructions of manufacturers on maximum time limits and by using stent logs to keep track of patients.

Combined Modality Therapy↗

PubMed1996

The effectiveness of imaging modalities in clinical staging of localized prostatic carcinoma.

Findings on transrectal ultrasonography (TRUS), computerized tomography (CT), and magnetic resonance imaging (MRI) in local staging of prostatic carcinoma (PCa) were compared with the final pathological staging in 30 patients who underwent radical prostatectomy. We found TRUS and MRI to have the same accuracy rate (53%) in local staging, whereas CT revealed a lower accuracy rate with 47%. TRUS revealed the highest accuracy rate in detecting seminal vesicle invasion with 70%, and MRI in invasion of periprostatic tissue with 67%. Although it revealed similar efficiency as MRI, TRUS should be considered as the first line modality in local staging of PCa in light of its relatively high accuracy rate, cost effectiveness and case in performance.

Aged↗

PubMed1996

Volume determinations by transrectal ultrasonography in patients with benign prostatic hyperplasia: correlation with removed prostate weight.

Estimation of prostate gland volume with transrectal ultrasonography (TRUS) provides important information in the evaluation of benign and malignant prostate disease. We evaluated 119 patients with clinically benign prostatic hyperplasia (BPH) by TRUS. Sixty-eight of these underwent transurethral resection of the prostate (TUR-P), and 51 patients underwent open prostatectomy. In both groups the estimated weight correlated well with the removed prostatic weight (r = 0.643, p < 0.0001 in TUR-P and r = 0.729, p < 0.0001 in open prostatectomy). We found that TRUS is a valuable method for estimation of prostatic volume in patients with BPH.

Aged↗

PubMed1996

Economics of different treatment options of benign prostatic hyperplasia in Turkey.

Benign prostatic hyperplasia (BPH) has an important impact on the national health economics and can be managed in a large spectrum of modalities from simple follow-up to surgery. In this study, we aimed to compare different treatment options of BPH in terms of cost effectiveness in Turkey. The first evaluation of a BPH patient has a cost of $200. The cost of TURP or open prostatectomy (OP) in our hospital including all the expenses is $740. Finasteride has an annual cost nearly equal to TURP and OP. Considering the expenses of the close follow-up studies and regular visits, one-year lasting Finasteride treatment is two times more expensive than surgery. In comparison with medical treatment options, TURP as the gold standard of treatment of BPH is cost effective when long-term expenses are considered.

Cost-Benefit Analysis↗

PubMed1996

Enzymatic treatment of ileal segments used for urinary tract reconstruction.

Urinary tract reconstruction by using various gastrointestinal segments is not devoid of complications which may hamper to a great extent the beneficial effects of the procedure. Intestinal mucosa is the primary site responsible for these complications and any procedure aiming at the prevention of untoward effects of intestinal interposition should abolish the absorptive and secretory functions of the mucosa. Augmentation cystoplasties by ileal segments were performed on 24 male albino Wistar rats. In 12 animals de-epithelialization of the mucosa with an enzymatic cock-tail, consisting of type I and type V collagenases and trypsin, preceded the cystoplasty. The functional capacity of the epithelium was determined by a simplified glucose absorption test in the third postoperative week. Morphological examination before the absorption test did not reveal any fibrosis or shrinkage of the ileal segments. Complete elimination of the absorptive capability in enzyme treated mucosa was found during the glucose absorption test, while a rapid and highly effective absorption was observed in the control group (p < 0.05). As a result, it seems possible to obtain intestinal segments covered with a mucosa which acquired similar characteristics to uro-epithelium, therefore closely resembling the original urinary tissues.

Anastomosis, Surgical↗

PubMed1996

Correlation of transrectal ultrasonography and core biopsies with pathology results in radical prostatectomy specimens.

BACKGROUND: We compared preoperative tumor location, as identified by transrectal ultrasonography (TRUS), and TRUS-guided core biopsies with the final histopathological examination of radical prostatectomy specimens. METHODS: Thirty patients who had radical retropubic prostatectomy after evaluation with TRUS are included in the study. Diagnosis of prostate cancer was established with TRUS-guided systematic (3 cores from base, mid and apex of the peripheral zone, and 1 core from the transition zone of each side of the prostate) and lesion-directed core biopsies in all cases. Each prostate gland was halved for histopathological examination and results are reported in terms of "sides". RESULTS: Histopathological examination of the prostatectomy specimens revealed prostate cancer bilaterally in 29 glands (58 sides) and unilaterally in 1 gland. Preprostatectomy TRUS examinations missed cancer in 29 sides, and core biopsies were negative for cancer in 14 sides. CONCLUSION: This study revealed that 49% of prostate cancer lesions (n = 29 sides) were not recognized on TRUS and 52% of those (n = 15 sides) were diagnosed only by additional systematic biopsies. Furthermore, even with TRUS-guided systematic core biopsies, failure to detect the prostate cancer lesions may be as high as 24% (n = 14 sides).

Biopsy↗

PubMed1996

Short-term effect of digital rectal examination on serum prostate-specific antigen levels. A prospective study.

OBJECTIVE: Prostate-specific antigen (PSA) is widely used as a tumor marker in the early detection of prostate cancer. However, its value is limited by several factors such as not being specific for the cancer tissue, diurnal variations of the secretion, and changes in the serum levels observed following rectal manipulations. The effect of digital rectal examination (DRE) on serum PSA levels is still debatable. METHODS: A prospective study is conducted by utilizing the IRMA count (monoclonal) PSA assay in order to determine the effect of DRE on PSA serum levels. A total of 50 men (median age 61, range 42-75 years) who presented to our outpatient clinic for the first time with lower urinary tract outflow obstruction symptoms were included in this study. Further evaluation revealed prostate cancer in 5 patients (10%) and benign prostate hyperplasia in the others. Blood samples were drawn for a PSA assay from all patients prior to and 30 min and 24 h following DRE (PSA 1-3). RESULTS: The mean PSA values prior to and 30 min and 24 h following DRE were 4.09 +/- 0.67 range 0.2-19.47) ng/ml, 4.50 +/- 0.63 (0.15-17.75), and 4.28 +/- 0.68 (0.23-24.12) ng/ml, respectively. The median PSA levels for PSA 1, PSA 2, and PSA 3 were 2.49 +/- 4.74, 3.22 +/- 4.48, and 2.62 +/- 4.82 ng/ml, respectively. Although, there was a statistically significant increase in serum PSA levels 30 min after DRE, the clinical significance of this increase in PSA values with a mean difference of 0.4 ng/ml remains to be clarified. CONCLUSION: Although the effect of DRE on PSA levels does not appear to be clinically significant, in order to prevent any confusion, it may be the best approach to perform DRE after obtaining serum for PSA analysis.

Humans↗

PubMed1996

Glutathione S-transferase and multidrug-resistant phenotype in transitional cell carcinoma of the bladder.

OBJECTIVE: To asses the role of expression of resistance phenotypes in treatment failure in patients with invasive transitional cell carcinoma of the urinary bladder, since P-glycoprotein and glutathione S-transferase pi (GST) expression are implicated in resistance to various chemotherapy agents in different tumors. METHODS: Tumor samples from P-glycoprotein and GST-pi were analyzed by immunohistochemistry. RESULTS: P-glycoprotein and GST-pi were found in 35.7 and 42.9% of the samples, respectively. In 21.4% of the samples there was simultaneous expression of both proteins. No significant impact on prediction of tumor behavior was evident on statistical analysis by any one of the protein expressions. CONCLUSION: Drug resistance in transitional cell carcinoma may be through different mechanisms. Although the small sample size of this study precludes firm conclusions, the assessment of P-glycoprotein or GST-pi expression appears to be of little value as a predictor of response to chemotherapy in this group of tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗