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Biomedical subjects

A Akdas

Publications and source records attributed to A Akdas.

At least 19 recordsLinked to original sources
PubMed2002

The efficacy of neoadjuvant chemotherapy in invasive bladder cancer.

Radical cystectomy is the gold standard in the treatment of invasive bladder cancer. However, five-year disease-free survival is low most probably due to micrometastatic disease at the time of surgery. The neoadjuvant chemotherapy may be performed as the first line management for invasive bladder tumors in order to treat micrometastases found at the diagnosis and improve resectability of larger neoplasms. A total of 43 patients diagnosed with invasive bladder tumors and 11 patients received neoadjuvant chemotherapy. The mean age of patients was 64 (43-74) years, and mean follow-up period was 52 months (12-114). Neoadjuvant chemotherapy protocol consisted of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) or cisplatin, methotrexate, and cisplatin (CMV). All patients in neoadjuvant chemotherapy group underwent radical cystectomy. There was no significant difference between the groups with respect to disease-free survival time and overall survival time. In patients who received neoadjuvant chemotherapy, the respective disease-free and overall survival times were 31 months and 36 months versus 30 months and 35 months in patients who were treated with surgery only (p > 0.05). Five-year survival rates were 36% and 31% in the chemotherapy and no-chemotherapy groups, respectively. In the present study, 5-year survival rate was not affected by neoadjuvant chemotherapy in invasive bladder tumor. Complete pathological remission (stage p0) was found in 28% and pathological downstaging (stage < T2) was seen in 9% of patients in the neoadjuvant chemotherapy group. Five-year survival rates were 75% and 14.2% in patients who responded to chemotherapy, and in patients with no response, respectively (p < 0.05). The most favorable prognostic factor in this study was the response to neoadjuvant chemotherapy revealed as complete remission or pathological downstaging. The most important issue remains the prediction of patients who would respond and benefit from neoadjuvant chemotherapy.

Adult↗
PubMed1999

Effect of urinary stone disease and extracorporeal shockwave lithotripsy on excretion of glycosaminoglycans.

BACKGROUND AND PURPOSE: The effect of glycosaminoglycans (GAGs) in urinary crystal inhibition has been shown in vitro, but their inhibitor role in vivo has not been precisely determined in stone-forming patients. The aim of this study was to compare the levels of total GAGs and their components in primary stone-forming patients and a healthy control group and to investigate the impact of shockwave lithotripsy (SWL). PATIENTS AND METHODS: Thirty-eight patients with primary kidney stones and 31 healthy controls were included in this prospective study. Total urinary GAG concentrations were determined by the dimethylene blue assay (DMB), and GAG fractions (chondroitin sulfate, heparan sulfate, and dermatan sulfate) were studied by cellulose acetate electrophoresis. Analysis was repeated after SWL in the stone patients. RESULTS: Chondroitin sulfate was the major component secreted in the urine of the control subjects. Heparan sulfate was the major component in the urine of the stone patients with less chondroitin sulfate and dermatan sulfate (48%, 35%, 16.5%, respectively). Our study showed a significant increase in total urinary GAGs (4.75 v. 7.43 microg/mg of creatinine; P<0.0001) after SWL. Dermatan sulfate was the main component in this group (P<0.0001). The total urinary GAG concentrations remained high for at least 2 days after SWL. CONCLUSION: The elevation in total GAGs after SWL indicates the presence of tissue injury, which also renders dermatan sulfate the principal excreted component. Studies with longer follow-up periods are needed to determine whether these changes in the excretion of GAG components persist.

Adult↗
PubMed1998

[Comparison among patients considered candidates for radical prostatectomy in academic institutes in different countries].

OBJECTIVE: Radical prostatectomy is performed in potentially curable prostatic cancers, but surgical indication might somehow depend on the idiosyncrasies of a population. Herein we compare the characteristics of patients undergoing radical prostatectomy in teaching University Hospitals of different countries. METHODS: We conducted a retrospective review on 250 consecutive patients who underwent radical prostatectomy before January 1997 in five teaching University Hospitals in Europe (Spain, Sweden, Switzerland, Turkey) and the United States (Detroit, MI). Clinicopathological data were recorded and compared, and a questionnaire investigated whether patient and physician attitudes towards surgery differed. RESULTS: The number of surgeries per month at each institution ranged from 0.9 to 10 and the proportion of newly diagnosed patients that undergo surgery from 0.14 to 0.36. The Kruskal-Wallis test revealed both median age and preoperative prostate-specific antigen (PSA) levels were different between groups. Similarly, despite standardized surgery and histologic work-up, differences in the detection of extracapsular invasion and the rate of detectable PSA after surgery were observed between institutions. Diagnosis in the Swedish and Swiss groups was more often based on digital rectal examination, while the rest were more confident with transrectal ultrasound. Doctors at some institutions were more inclined to recommend radical surgery, either by not mentioning or disapproving other therapeutic strategies. The proportion of patients who said they would elect surgery again ranged from 72% to 92%, and the proportion of doctors who said they would perform surgery again ranged from 78% to 100%. Patients' and doctors' degree of satisfaction with the decision made were also different. CONCLUSIONS: (i) Candidates for radical prostatectomy in teaching hospitals of several countries are different. Might therefore have practical implications on the design of clinical trials and the interpretation of the results of treatment. (ii) Patient and physician acceptance of surgery varies according to countries and is more established firm in those countries where it is more frequently performed.

Adult↗
PubMed1997

The role of free prostate-specific antigen in the diagnosis of prostate cancer.

OBJECTIVE: To determine whether the free/total prostate-specific antigen (PSA) ratio can discriminate between patients with prostate cancer or benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: A prospective study was conducted using free and total PSA assays in patients who underwent transrectal-ultrasound guided biopsies indicated by a total serum PSA level of > 4 ng/mL and/or a positive digital rectal examination. Sixty-nine men (median age 68 years, range 57-86) who presented to our out-patient department with symptoms of prostatism were included in the study. Blood samples were drawn from all patients before biopsy. RESULTS: Histopathological examination detected prostate cancer in 17 of 69 (25%) patients and 13 of these 17 patients had a free/total PSA ratio of < 0.15; only 12 of 52 (23%) patients with BPH had a ratio of < 0.15. Receiver operating characteristic analysis indicated a threshold free/total PSA ratio of < or = 0.15 was the optimum discriminatory level. In the whole study group, this threshold had sensitivity, specificity, positive- and negative-predictive values of 76%, 77%, 52% and 91%, respectively. There were 40 patients with serum PSA levels of 4-10 ng/mL and 17.5% (7/40) of these were diagnosed with cancer. Using a free/total PSA ratio of 0.15 would have failed to diagnose two patients of seven with prostate cancer but 30 patients would have avoided a biopsy. In this subgroup, the threshold ratio of 0.15 had sensitivity, specificity, positive- and negative-predictive values of 71%, 85%, 50% and 93%, respectively. The rates for a PSA density (PSAD) at a threshold of > or = 0.15 were 71%, 76%, 38%, 93%, respectively. CONCLUSION: These results indicate that using the free/total PSA ratio gives a significant improvement over PSAD and total PSA values alone in the diagnosis of prostate cancer: its use may also enhance the diagnostic accuracy in patients with intermediate PSA levels.

Aged↗
PubMed1997

Nuclear accumulation of mutant p53 protein: a possible predictor of failure of intravesical therapy in bladder cancer.

OBJECTIVE: To investigate the expression and importance of the nuclear accumulation of p53 in superficial transitional cell carcinoma (TCC) of the bladder and its role as a predictor of response to treatment. PATIENTS AND METHODS: Tumour samples from 30 patients (two women and 28 men, mean age 60.1 years, range 44-75) with pTa/pT1 tumours were assessed immunohistochemically using the Pab1801 monoclonal antibody and standard avidin-biotin peroxidase staining for p53 protein. RESULTS: Tumours from six patients (20%) showed nuclear accumulation of p53; five of these patients failed intravesical therapy with bacille Calmette-Guèrin (BCG) and progressed to muscle invasive and/or metastatic disease, in contrast to six of 24 patients with no detectable nuclear oncoprotein. CONCLUSIONS: The nuclear accumulation of p53 appears to be a prognostic indicator of tumour unresponsive to intravesical treatment, even with the most potent agent (BCG). Therefore, early radical treatment modalities must be seriously considered in this group of patients.

Administration, Intravesical↗
PubMed1997

Evaluation of prostate specific antigen density and transrectal ultrasonography-guided biopsies in 100 consecutive patients with a negative digital rectal examination and intermediate serum prostate specific antigen levels.

BACKGROUND: This study was undertaken to assess the importance of prostate biopsies in patients with a negative digital rectal examination (DRE) and elevated prostate specific antigen (PSA) levels and to investigate the role of PSA density (PSAD) and hypoechoic lesions on transrectal ultrasound (TRUS) in increasing the diagnostic sensitivity and specificity for prostate cancer (PCa). METHODS: One hundred patients with varied initial symptoms who had a negative DRE and a PSA level between 4 and 20 ng/mL underwent TRUS-guided systematic and, if present, lesion-directed biopsies. RESULTS: PCa was detected in 11 patients (11%). TRUS examinations revealed hypoechoic lesions in 31 patients. Lesion-directed biopsies revealed PCa in 13% (4/31) of patients with abnormal TRUS whereas, 7% (5/69) of patients with negative TRUS findings had PCa. Additional systematic biopsies detected PCa in 2 patients where lesion-directed biopsies were negative. None (0/19) of the lesions smaller than 0.2 mL on TRUS had PCa whereas, 33% (4/12) of patients with lesions greater than 0.2 mL had PCa. When the subgroup of patients with negative TRUS and PSA levels between 4 and 10 ng/mL were considered, 25% (1/4) of cases with PCa would have been missed if 0.15 was used as the cut-off point for PSAD, however, this would save 61% (30/49) of unnecessary biopsies. The positive predictive value of PSA (cut-off level 10 ng/mL), PSAD (cut-off level 0.15), and hypoechoic lesions on TRUS were found to be 11.5%, 33%, and 13%, respectively. When hypoechoic lesions greater than 0.2 mL were taken as the positive finding, the positive predictive value and specificity rates of TRUS increased to 33% and 91%, respectively, without any change in the sensitivity. CONCLUSIONS: In patients with a negative DRE and intermediate PSA levels, the application of PSAD would have saved 49% of study patients with BPH from a biopsy, but would have missed 27% of PCa cases. By ignoring lesions smaller than 0.2 mL on TRUS, a very high specificity of 91% was achieved with a sensitivity of 36%. Thus, further investigations aimed at defining a better mode of diagnosis of PCa are warranted.

Biopsy↗
PubMed1996

The impact of prostate-specific antigen density in predicting prostate cancer when serum prostate-specific antigen levels are less than 10 ng/ml.

OBJECTIVE: To evaluate the impact of prostate-specific antigen density (PSAD) when serum levels of prostate-specific antigen (PSA) are less than 10 ng/ml. METHODS: We retrospectively analyzed 134 patients who underwent transrectal ultrasound (TRUS)-guided prostate biopsies according to Cooner's algorithm. RESULTS: Histopathological examination revealed prostate cancer (PCa) in 22 (16%) and benign prostatic hypertrophy (BPH) in 112 (84%) patients. Five patients (23%) with PCa had PSAD < 0.15 of whom 3 had PSA < 4 ng/ml and 2 had PSA between 4 and 10 ng/ml. In the BPH group, 60 patients (54%) had PSAD below 0.15 whereas 52 patients (46%) had PSAD over 0.15. With 0.15 as the cutoff level of PSAD, the sensitivity and specificity of PSAD was found as 77 and 54%, respectively. In this patient population, PSA with the cutoff level of 4 ng/ml has sensitivity and specificity levels of 77 and 33%, respectively. According to these results, a statistically significant difference was found between PSA and PSAD only in terms of diagnostic specificity (chi-square, p < 0.05). There were 29 patients with negative digital rectal examination (DRE) and TRUS and PSA 4-10 ng/ml who underwent biopsy because of PSAD > 0.15. No cancer was detected in this group of patients, suggesting that biopsy in this subgroup may be unnecessary. CONCLUSION: Although PSAD seemed to increase the specificity without any decrease in sensitivity in the diagnosis of prostate cancer, it did not bring any practical advantage in our selected population since all PCa cases had abnormal DRE and/or TRUS findings.

Aged↗
PubMed1995

When should one perform shockwave lithotripsy for lower caliceal stones?

Extracorporal shockwave lithotripsy of lower caliceal stones is often unrewarding because of the difficulty of passing stone fragments. We report our results in SWL of lower pole stones in 219 patients and compare them with the results of SWL of middle (82 patients) and upper pole (85 patients) stones. The stone-free rate of SWL monotherapy was found to be 59%, 77%, and 64% in lower, middle, and upper caliceal stones, respectively. In lower pole stones, SWL was unsuccessful in 41% of the patients, of whom 9% had minimal residual asymptomatic stones (less than 4 mm in greatest diameter). In comparison with the results of percutaneous nephrolithotomy (PCN) of lower pole urolithiasis in the literature, SWL was unsuccessful in large stones, with stone-free rates of 13% and 0 when the stone size was 3 to 4.9 cm2 and > 5 cm2, respectively. A stone-free rate of 82% when the stone burden was < 1 cm2 is similar to the PCN results of other centers, suggesting that SWL may be the first choice of treatment in lower pole stones of this size. We achieved a stone-free rate of 59% when the stone size was between 1 and 3 cm2, which is lower than the stone-free rates of PCN in the literature. In spite of its lower stone-free rates, SWL, with its lower morbidity, may still be considered an acceptable treatment modality in this range of moderate stone burden, especially when there is a patient desire for conservative treatment.

Adolescent↗
PubMed1995

The diagnostic accuracy of digital rectal examination, transrectal ultrasonography, prostate-specific antigen (PSA) and PSA density in prostate carcinoma.

OBJECTIVE: To evaluate the efficacy of digital rectal examination (DRE), transrectal ultrasonography (TRUS), prostate-specific antigen (PSA) and PSA density (PSAD) in the diagnosis of prostate cancer (CaP). PATIENTS AND METHODS: Retrospective data were analysed from a selected population of 159 patients (mean age 66.7 years, range 50-83), 56 with histologically diagnosed CaP and 103 with benign prostatic hyperplasia (BPH). RESULTS: Among the four methods, DRE was found to have accuracy, sensitivity and specificity rates of 79.9, 91 and 73.8% respectively. The most common clinical practice, the combination of PSA (> 4 ng/mL), DRE and TRUS, showed a higher accuracy, a similar specificity rate, but a lower sensitivity (84.2, 91.2 and 71.4%, respectively). Rates from the combination of PSAD (> 0.15 ng/mL/cm3) with DRE and TRUS were not significantly different from those obtained using the combination of PSA, DRE and TRUS. CONCLUSION: PSAD alone or in combination did not improve the diagnostic value of PSA. We cannot claim DRE was the best method for the diagnosis of CaP, because this study group did not represent a true screening population. However, this study revealed that DRE should not be omitted from the physical examination of patients and, despite technological developments, it remains a major tool in the diagnosis of CaP.

Aged↗
PubMed1994

Nuclear casein kinase 2 (CK-2) activity in human normal, benign hyperplastic, and cancerous prostate.

In previous work, we had observed that chromatin-associated nonhistone protein phosphorylation, catalyzed by intrinsic protein kinase reaction in chromatin preparations from human benign prostatic hyperplasia (BPH) prostate samples was markedly elevated, compared with the normal prostate chromatin samples [Rayan et al: Cancer Res 45:2277-2282, 1985]. The properties of this protein kinase reaction were suggestive of the involvement of casein kinase(s). By employing the specific synthetic substrate for casein kinase 2 (CK-2) for assays in cellular fractions, we have shown that this protein kinase is present in human prostate chromatin. Its activity is increased in BPH chromatin by about 25-fold, as compared with its activity in the normal prostate chromatin. This suggests that CK-2 is a possible mediator of the enhanced phosphorylation of chromosomal proteins in BPH chromatin. By comparison, CK-2 activity in chromatin preparations from prostatic carcinoma samples was markedly less elevated than that of the BPH chromatin. Immunohistochemical analysis of the enzyme in human frozen sections of prostate tissue samples showed that the enzyme immunostaining was diffuse in the cytoplasm, but more intense in the nucleus, especially in the nucleoli. In general, the staining corresponded with the enzymic data. However, sections from prostatic carcinoma samples appeared to show differential staining, depending on the Gleason's grade of the sample. The samples with higher Gleason's grade showed less intense immunostain in the nucleus, compared with samples of lower Gleason's grade. Further, regions of sections in samples with higher Gleason's grade did not show any immunostaining. These differences in the characteristics of CK-2 expression in prostatic carcinoma samples may be potentially significant, but need to be evaluated further for their significance to the pathobiology of prostatic neoplasia.

Amino Acid Sequence↗
PubMed1993

Extracorporeal shock wave lithotripsy monotherapy of staghorn calculi with Dornier MFL 5000.

A retrospective study was conducted of the efficacy of extracorporeal shock wave lithotripsy (SWL) monotherapy for the management of 31 patients with staghorn calculi (mean size 5.2 cm2). Five patients were lost to follow-up, 10 were stone-free in the end, and 11 had effective disintegration with small residual fragments. The remaining five patients required open surgery because of insufficient stone fragmentation. According to our data, SWL monotherapy is not sufficient for achieving stone-free status in patients with staghorn calculi, but it relieves obstruction and decreases the stone bulk in the majority of them.

Adult↗
PubMed1992

High-dose epirubicin in chemotherapy refractory non-seminomatous germ cell cancer: a phase II study. EORTC Genito-Urinary Tract Cancer Co-operative Group. EORTC Early Clinical Trials Group.

Eighteen patients with progressive disseminated, platinum-resistant germ cell tumors were treated with epirubicin 135 mg/m2, every 3 weeks. One patient had stable disease, 17 developed progression. Myelosuppression was dose-limiting. One patient died of neutropenic septicemia. High-dose epirubicin is not active against platinum-resistant germ cell cancer.

Adolescent↗
PubMed1992

Preliminary results of transurethral microwave thermotherapy in the treatment of benign prostatic hyperplasia in Turkey.

This prospective study was conducted in order to evaluate the efficacy of transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia (BPH). A single TUMT session of 55 min was delivered as an ambulatory procedure without anesthesia to 180 patients. 20 (69%) of the 29 patients who were catheterized due to urinary retention prior to the treatment were able to urinate freely after the treatment. In 91 patients with a follow-up of 3 months, the mean maximum flow rate (MFR) was 7.9 ml/s prior to the treatment and 12.1 ml/s after the treatment (p less than 0.02). The mean residual urine after voiding (PVR) of these patients was 104 and 54 ml before and after TUMT, respectively (p = 0.0001). The mean Madsen symptom score (SS) was 14 before and 7.5 after the treatment (p = 0.0001). The patients with pretreatment MFR higher than 7.0 ml/s, PVR less than 150 ml and SS lower than 15 benefited better from TUMT. As the findings indicated, TUMT is an alternative treatment modality in BPH in selected cases, although the number and the follow-up of our series are insufficient to draw a precise conclusion yet.

Aged↗
PubMed1990

The relation of prostatic acid phosphatase and prostate specific antigen with tumour grade in prostatic adenocarcinoma: an immunohistochemical study.

This study examines the relationship between the presence of prostatic acid phosphatase (PAP) and prostate specific antigen (PSA) in tissue, the serum PAP and PSA levels and tumour grade in prostatic adenocarcinoma. Thirty-three tumours were studied by the indirect immunoperoxidase method for PAP and PSA production. Thirty-one of them were stained positive for both markers. The remaining two which previous histopathological studies suggested were transitional cell carcinoma, stained negative. In primary tumours there was a weak trend for poor immunoreactivity in high grade neoplasms but the correlation was not significant. The elevated serum PAP and PSA levels did not correlate with the intensity of staining in the tissue.

Acid Phosphatase↗