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Biomedical subjects

U Yilmaz

Publications and source records attributed to U Yilmaz.

At least 19 recordsLinked to original sources
PubMed2006

Lamivudine therapy in kidney allograft recipients who are seropositive for hepatitis B surface antigen.

BACKGROUND: There are numerous recent reports on the use of lamivudine for hepatitis B virus (HBV) infection after renal transplantation. However, the optimal strategy (prophylactic, preemptive, or salvage approach) for starting lamivudine treatment in this patient group has not been determined. The aim of this study was to assess how the timing of lamivudine therapy affected the HBV serological status and the transaminase levels in renal allograft recipients with chronic HBV infection. METHODS: We investigated outcomes for patients who were seropositive for hepatitis B surface antigen (HBsAg) and underwent transplantation before or after October 2004 (the date our institution implemented a prophylactic lamivudine treatment strategy against HBV). The data included serum liver enzyme levels and polymerase chain reaction (PCR) screening results for HBV-DNA in serum. RESULTS: Fifteen patients (11 before October 2004, four after October 2004) were included in the study. Preoperatively all patients had normal transaminases levels and 2 of 15 patients had detectable HBV-DNA on PCR. Eight of the 15 total HBsAg-positive patients in our series were not placed on lamivudine at the time of renal transplantation. Half of those who were not treated initially showed transaminase elevations in the first year of follow-up requiring lamivudine therapy at that time. In contrast, all seven individuals who received lamivudine at the time of transplantation were negative for HBV-DNA throughout the follow-up. CONCLUSION: To prevent viral replication in HBsAg-positive patients who are scheduled for renal transplantation, it is best to initiate lamivudine therapy before or immediately after transplantation.

Antiviral Agents↗
PubMed2006

Venous complications after orthotopic liver transplantation.

We report venous complications, including portal vein and hepatic vein stenoses, that required interventional radiological treatment in three pediatric and two adult living related liver transplant recipients. Between April 2001 and April 2005, 81 liver transplantations were performed at our hospital. Sixty-two grafts were from living donors. During follow-up, three portal vein stenoses were identified in three pediatric recipients, and two hepatic vein stenoses in two adult patients. In the children, two had received left lateral segment grafts, and one had received a right lobe graft from two mothers and one father, respectively. The etiologies of liver failure were Alagille syndrome, biliary atresia, and fulminant Wilson's disease. Portal vein stenoses were identified at 8, 11, and 12 months after transplantation; all three patients underwent percutaneous transhepatic portal venous angioplasty with a success rate of 100%. The mean follow-up was 102 days; no recurrence has occurred. In contrast, hepatic venous stenoses were diagnosed in two adult recipients. One of them was a 24-year-old woman with autoimmune hepatitis and the other a 43-year-old man with cryptogenic cirrhosis. Hepatic vein stenoses were diagnosed at 3 and 4 months after transplantation. Both hepatic vein stenoses were dilated with balloon angioplasties via the transjugular route. Venous complications identified by Doppler ultrasonography were confirmed by computerized tomographic angiography. Angioplasty represents an effective and safe alternative to reconstructive surgery in the treatment of venous complications after liver transplantation.

Adolescent↗
PubMed2006

Safety of multidetector computed tomography in calculating liver volume for living-donor liver transplantation.

Living-related liver transplantation was developed to overcome the organ shortage for both children and adults with end-stage liver disease. Because impaired liver function after resection and transplantation is caused by insufficient liver volume, the reliable volumetric assessment of the hepatic segments of potential living donors is a critical element in preoperative evaluation. In this study, we compared the results of multidetector computed tomographic (CT) volumetry with the intraoperative findings from 80 liver transplantations performed at our center. Resection borders were determined preoperatively with the aid of CT by manual delineation in which the hepatic vessels were used as guides. Resected liver grafts were weighed intraoperatively, and the calculation of their volume was based on the specific weight of 1 g/mL. Statistical analyses were performed with Pearson's correlation test; P < .05 was considered significant. The study subjects consisted of 48 women and 32 men (mean age, 35.6 +/- 9.7 years; range, 23-56 years). Forty-one donors underwent right lobectomy, 22 underwent left lobectomy, and 17 underwent left lateral segmentectomy. Manual volumetric measurement was completed within 15 minutes. No significant differences were found between the results of preoperative volumetry and the intraoperative measurement. We therefore concluded that manual CT volumetric calculation is a reliable method of calculating liver volume for living-donor liver transplantation.

Algorithms↗
PubMed2006

Bax, bcl-2 and c-kit expression in non-small-cell lung cancer and their effects on prognosis.

In non-small-cell lung cancer (NSCLC), stage of the disease is still the most important prognostic factor. Other than stage, many biological markers and many other prognostic factors are studied to define their effects on prognosis of lung cancer. In this study, we aimed to evaluate the expressions of Bax and bcl-2 genes which are important in apoptosis and c-kit, which is a tyrosine kinase transmembrane receptor, as well as searched their response to treatment modalities and effects on survival. Sixty-nine NSCLC cases' pathological samples were stained with specific Bax, bcl-2 and c-kit dyes by immunohistochemical (IHC) methods. IHC evaluation was done by the semichantitative method according to the distribution and intensity of the staining. Twelve of 69 cases (17.4%) were stage I, 28 (40.5%) were stage II, 17 were (24.6%) stage IIIA, nine cases were (13.1%) stage IIIB and three cases (4.4%) were stage IV patients. Their histological subtypes were as follows: of 69 cases, 36 (52.2%) were squamous cell carcinoma, 28 (40.6%) were adenocarcinoma, five (7.2%) were adenosquamous cell carcinoma (two patients) and large-cell carcinoma (three patients). The positive immunostaining rates for Bax and bcl-2 in whole group, squamous cell carcinoma and adenocarcinoma groups were 40.6%/36.2%, 55.6/69.4% and 25.0/0.0%, respectively. The positive immune staining rates for c-kit in whole group, squamous cell carcinoma and adenocarcinoma groups were 7.2, 5.6 and 7.1%, respectively. We didn't find any correlation with Bax, bcl-2 and c-kit expressions and clinicopathological parameters such as age, tumour size, lymph node involvement, smoking, stage of the disease, response to radiotherapy and chemotherapy. Results are interpreted according to survival; bax and bcl-2 expressions were not so effective both in whole group and histologically subgrouped patients. C-kit expression was also found not related with survival in whole group whereas found as a bad prognostic factor in patients with squamous cell carcinoma. These findings could indicate that the expression of apoptotic pathway markers and c-kit may have a role in the prognosis of early stage NSCLC, especially with squamous cell carcinoma subtype.

Apoptosis↗
PubMed2005

The role of early colonoscopy in CMV colitis of transplant recipients.

Cytomegalovirus (CMV)-associated diseases remain a major problem in transplant recipients. Early diagnosis is critical. Presentation of early CMV colitis can be mild and nonspecific in transplant recipients. Although serology is helpful in the diagnosis, sometimes it is inadequate. Because the endoscopic features of CMV colitis are specific, colonoscopy facilitates the histopathologic examination. We present the clinical properties and advantages of early colonoscopy in transplant recipients with CMV colitis. The study group included seven patients (six men, one woman of mean age, 36.7 years (range, 22 to 64 years) whose mean transplant duration was 12.3 months (range, 1 to 72 months). Six of the seven patients experienced an acute graft rejection treated with high doses of steroids; one patient had a herpes simplex virus infection. All patients were on steroid treatment with a various combinations of immunosuppressive agents, including cyclosporine, mycophenolate mofetil, and tacrolimus. All patients presented with mild diarrhea without any blood or mucous discharge. Four patients had fever exceeding 38 degrees C; two had abdominal pain. Stool examinations revealed normal findings in six patients, while one patient had white blood cells and amoebic cysts. Serum CMV IgM and CMV pp65 antigenemia were negative in five of seven patients and two had positive results. All patients showed typical colonoscopic and histopathologic findings compatible with CMV colitis. Standard ganciclovir treatment was successful in all patients. Early and rapid colonoscopy is beneficial for the early diagnosis and management of CMV colitis in transplant recipients.

Adult↗
PubMed2005

CT in differential diagnosis of benign and malignant pleural disease.

BACKGROUND: CT plays a valuable role in assessment of patients with a wide variety of diseases of the pleura, and pulmonologists should be aware of the significance of different CT findings for the differential diagnosis of benign and malignant pleural diseases. METHODS: 155 patients with pleural disease who had undergone CT scans of the lungs and thorax before treatment were enrolled. We retrospectively reviewed CT findings in 146 patients with proven pleural disease. RESULTS: Fifty-nine of the cases were malignant, 87 of them had benign pleural diseases. CT findings that were helpful in distinguishing malignant from benign pleural disease were: 1) pleural nodularity; 2) rind; 3) mediastinal pleural involvement; and 4) pleural thickening greater than 1 cm. The sensitivities and specificities were 37%/97%, 22%/97%, 31%/85%, 35%/87%, respectively. CT findings differentiating malignant pleural mesothelioma from metastatic pleural disease were identified. Findings for malignant mesothelioma were as follows: 1) involvement of interlobar fissure (sensitivity 30%, specificity 92%), 2) pleural thickening greater than 1 cm (sensitivity 60%, specificity 77%). Whereas, findings for metastatic pleural disease were mediastinal/hilar lymph node enlargement and lung parenchymal involvement (P < .05). CONCLUSION: CT is helpful in the differential diagnosis of pleural diseases, particularly in differentiating malignant from benign conditions and metastatic pleural disease from malignant mesothelioma.

Chi-Square Distribution↗
PubMed2004

Role of penile electrodermal activity in the evaluation of autonomic innervation of corpus cavernosum.

Electrodiagnostic tests measuring the activities of cavernous smooth muscle and sudomotor structures of penile skin are used in order to evaluate autonomic innervation of the penis. Owing to closeness of these tissues, the interference of sympathetic activity during recording is a possibility. In this study, we investigated this possibility in 10 patients whose cavernosal tissues were destroyed during penile prosthesis implantation by comparing the pre- and postoperative penile skin electrodermal activities. Penile electrodermal activities were recorded with surface electrodes before and after the operation. All of the patients had spontaneous and evoked penile electrodermal activity (EDA). The mean amplitude of evoked EDA decreased from 2159+/-700 to 1413+/-515 microV following penile prosthesis surgery (P=0.017). The decrease in the amplitude of penile-evoked EDA following penile prosthesis implantation suggests the contribution of cavernous smooth muscle activity to the sudomotor responses prior to operation. Although corpus cavernosum sympathetic activity contributes to the penile skin recordings, these recordings are mostly the result of penile skin sudomotor sympathetic activity. Therefore, surface potentials recorded from penile skin should not be used for the evaluation of autonomic innervation of corpus cavernosum.

Adult↗
PubMed2004

Acute pancreatitis due to ramipril therapy.

Few data exist about the incidence of drug induced acute pancreatitis in the general population. Drugs are related to the aetiology of pancreatitis in about 1.4%-2% of cases. Although angiotensin converting enzymes are generally well tolerated, acute pancreatitis has been reported in a few subjects treated with captopril, enalapril, and lisinopril. A 85 year old man with a long standing history of hypertension, who was treated with ramipril 5 mg once daily, presented with acute pancreatitis. Other causes of the disease were ruled out. After cessation of ramipril his condition improved and amylase level decreased. This was his third episode of acute pancreatitis since ramipril was started in 2000. To the authors' knowledge ramipril induced pancreatitis has not previously been reported.

Acute Disease↗
PubMed2001

Evrim Bougie: a new instrument in the management of urethral strictures.

BACKGROUND: In this study a new instrument and technique is described for the endoscopic treatment of complete posterior urethral strictures, which may result in serious complications and sometimes require troublesome treatments. METHODS: Three patients with complete posterior urethral obstruction were treated endoscopically with the guidance of a new instrument: Evrim Bougie. Evrim Bougie looks like a Guyon Bougie, has a curved end, which facilitates getting into the bladder through the cystostomy tract and with a built in channel of 1.5 mm in diameter for a sliding needle exiting at its tip. Having confirmed fluoroscopically and endoscopically that the sliding needle had passed across the strictured segment, the strictured segment was incised with internal urethrotomy, distal to the strictured segment, and urethral continuity was accomplished. At the end of the operation a Foley urethral catheter was easily placed into the bladder per urethra. Patients were instructed in self-catheterization after removal of the urethral catheter. All patients achieved normal voiding at postoperative 7th month follow-up evaluation. CONCLUSION: Internal urethrotomy could be performed under the guidance of the sliding needle of Evrim Bougie advanced from above the posterior urethral strictures, which to our knowledge was described for the first time in the English literature. We also believe that there may be other possible indications of Evrim Bougie for different procedures in urethral surgery.

Adult↗
PubMed2001

Auditory event-related potentials in patients with premature ejaculation.

OBJECTIVES: To investigate in a descriptive manner the P300 component of the event-related potential (ERP), which is related to aspects of cognitive processing, in patients with premature ejaculation (PE) to determine whether there is a cognitive alteration in this condition. Recent studies with short latency evoked potentials such as cortical somatosensory evoked potentials have indicated that afferent sensory inputs from the genital area to the nervous system are increased in PE. However, the cortical neural process of ejaculation has remained poorly understood. METHODS: We performed ERPs in 20 patients with PE and in 20 age-matched healthy subjects. ERPs were evoked by an auditory oddball paradigm consisting of 150 tone bursts (80% 1 kHz; 20% 2 kHz). The latencies of the N200 and the P300 waves and the amplitude of the P300 wave were measured. RESULTS: The mean latencies of the N200 and P300 waves were significantly longer in the patients with PE than in the controls (P <0.04 and <0.03, respectively). No significant difference was found in the P300 amplitude between the controls and patients (P >0.05). CONCLUSIONS: These data indicate that the greater cortical representation of sensory stimuli from the genital areas that has been shown with somatosensory evoked potential studies might be related to a cognitive/neurobehavioral dysfunction. The dysfunction involves an increased time to evaluate and categorize the stimuli in the central nervous system, with no change in the quality of cognition and neural disinhibition by the prefrontal cortex to early sensory processing in subcortical or primary cortical regions, which are cognitive neural processes underlying ERP generation.

Adult↗
PubMed2001

Endoscopic management of a duodenal duplication cyst associated with biliary obstruction in an adult.

Duodenal duplication cysts are distinctly uncommon and most often present in infancy or early childhood. The clinical presentation is generally duodenal obstruction, hemorrhage, or pancreatitis. Duodenal duplication cysts rarely cause biliary obstruction in adults. So far, duodenal duplication cysts have been almost exclusively treated by surgical intervention. This report describes both endoscopic diagnosis and treatment of a large periampullary duodenal duplication cyst associated with biliary obstruction in an adult patient.

Adult↗
PubMed2000

Does pleurodesis for pleural effusions give bright ideas about the agents for hydrocele sclerotherapy?

OBJECTIVE: Evaluation of the effectiveness of rifampicin and some agents used in the pleurodesis of pleural effusions, such as autologous blood and purified mineral talc. PATIENTS AND METHODS: A total of 56 hydroceles were treated by sclerotherapy, in a random fashion, using purified mineral talc, rifampicin and autologous blood as sclerosant agents. The control group of patients were handled with aspiration only. RESULTS: The cohort of patients in the blood group had a success rate comparable to the control group (p > 0.05). the rifampicin group did better than both control and blood groups (p < 0.05) but not better than the talc group (p < 0.01). Success rate was highest in the talc group of patients who needed no re-sclerotherapy procedures. CONCLUSION: Purified mineral talc was shown to be potentially the best sclerosant for the sclerotherapy of hydroceles and epididymal cysts.

Adult↗
PubMed2000

The effectiveness of tenoxicam vs isosorbide dinitrate plus tenoxicam in the treatment of acute renal colic.

OBJECTIVE: To determine the effectiveness of isosorbide dinitrate in combination with tenoxicam compared with tenoxicam alone for the relief of acute renal colic. PATIENTS AND METHODS: Fifty patients with acute renal colic were randomly and in a double blind fashion divided into two treatment groups of 25 each. Group 1 received tenoxicam (40 mg intravenously) and group 2 received tenoxicam (40 mg intravenously) plus sublingual isosorbide dinitrate (5 mg). The patients were compared for visual pain scores, heart rate and blood pressure between and within the groups before and after treatment. RESULTS: Comparing the groups, group 2 had significantly lower pain scores after treatment (P < 0.05) but no other variables were significantly different (P > 0.05 for each). Within the groups the pain scores were significantly lower after treatment in both groups (P < 0.05). Group 2 also had a significantly lower heart rate and blood pressure after treatment (P < 0.05). There were no side-effects caused by tenoxicam and isosorbide dinitrate in either group. CONCLUSION: The use of tenoxicam alone or combined with isosorbide dinitrate was effective in relieving of renal colic, but the relief obtained with the combination was significantly greater than tenoxicam alone.

Acute Disease↗
PubMed2000

The postejaculatory refractory period: a neurophysiological study in the human male.

OBJECTIVE: To investigate changes in the penile sensory threshold, and the variables of cortical somatosensory evoked potential and sacral evoked response tests in the early postejaculatory period in the human male. SUBJECTS AND METHODS: Twenty healthy volunteers (mean age 25.3 years, range 17-32) were evaluated before and after ejaculation for penile sensory threshold values, and the variables of sacral evoked response and cortical somatosensory evoked potential tests. RESULTS: Three subjects were excluded from the statistical analyses because there were significant differences among the repeated tests. In the remaining 17 subjects the penile sensory threshold was significantly greater in the postejaculatory period (P < 0.05). There were no significant changes in the other variables of both the sacral evoked response and cortical somatosensory evoked potential tests after ejaculation (P > 0.05). CONCLUSION: The postejaculatory refractory period in the human male is accompanied by a greater penile sensory threshold but with no change in the values of the sacral evoked response and cortical somatosensory evoked potential.

Adolescent↗
PubMed1999

The effects of fluoxetine on several neurophysiological variables in patients with premature ejaculation.

PURPOSE: Fluoxetine, a selective serotonin re-uptake inhibitor, has been shown to increase the intravaginal latency of patients with premature ejaculation. We demonstrated the effects of fluoxetine on intravaginal latency, penile sensory threshold, and variables of sacral evoked response and cortical somatosensorial evoked potential in patients with premature ejaculation. MATERIALS AND METHODS: Of 48 patients 40 who presented to our clinic with premature ejaculation met the study criteria, gave written or oral consent, and were divided randomly in a double-blind fashion into 2 groups of 20 patients. The study group received 20 mg. fluoxetine daily and the control group received placebo for 1 month. The patients were evaluated during visits before and after treatment for intravaginal latency, penile sensory threshold values, and the variables of sacral evoked response and cortical somatosensory evoked potential tests. RESULTS: Patient ages, intravaginal latencies, penile sensory threshold values, and amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential tests in both groups were not significantly different at the beginning of treatment (p >0.05). At the end of treatment intravaginal latencies and penile sensory threshold values were increased in the study group compared to before treatment and the control group (p <0.05). No change was observed in either group for the amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential tests (p >0.05). CONCLUSIONS: These findings suggest that fluoxetine is effective treatment for premature ejaculation probably due to its effect of increasing the penile sensory threshold, without changing the amplitudes and latencies of sacral evoked response and cortical somatosensory evoked potential.

Adult↗
PubMed1999

Visual symptoms and G-LOC in the operational environment and during centrifuge training of Turkish jet pilots.

BACKGROUND: High-performance fighter aircraft produce high-sustained +Gz forces with rapid onset rates. Because of this G-producing capability, military jet pilots are subjected to physiological stress, which may lead to visual disturbances and G-induced loss of consciousness (G-LOC). Although visual disturbances are very common in jet flights, G-LOC is relatively rare but more dangerous. The frequency and causes of G-LOC need to be determined in the interest of flight safety. METHODS: Part I. A survey was conducted on Turkish jet pilots to reveal the incidence of symptoms due to +Gz acceleration. Anonymous questionnaires were given to F-16, F-4, and F-5 pilots. They consisted of inquiries about the occurrence of visual symptoms and/or G-LOC during +Gz acceleration in the operational environment. Part II. During the years 1992-1996, 486 F-16, 801 F-4, and 256 F-5 fighter pilots underwent high "G" training at Turkish Aerospace Medical Center and they were assessed in terms of G-LOC rates. RESULTS: Part I. A total of 325 pilots who flew T-37 in undergraduate pilot training (UPT) answered the questionnaire. The pilots were divided into 3 groups according to the types of aircraft, which they fly now: 116 F-16, 182 F-4, and 27 F-5 pilots. A total of 311 pilots (95.7%) reported having experienced greyouts and/or blackouts. With 25 pilots (7.7%) experiencing G-LOC, the G-LOC frequency according to the type of aircraft was: 5.2% (T-37) [in UPT]; 4.3% (F-16), 1.6% (F-4), and 0% (F-5). Part II. In centrifuge training, the incidence of G-LOC in pilots of the various types of aircraft were: 12% (F-16), 6.4% (F-4), and 8.6% (F-5). CONCLUSIONS: Centrifuge training reduces G-LOC rates of subsequent centrifuge training; and it is hoped might reduce the G-LOC rate in the operational environment. Almost all jet pilots reported having experienced +Gz related visual symptoms, but G-LOC seems to be a more common problem for pilots who fly rapid onset rate aircraft than pilots who fly high "G" capable but lower G onset rate aircraft.

Acceleration↗