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Biomedical subjects

M Parlak

Publications and source records attributed to M Parlak.

At least 19 recordsLinked to original sources

Effects of a soil conditioner on some physical and biological features of soils: results from a greenhouse study.

A soil amendment substance-organic bio-stimulator, Terralyt Plus (TP), was used to observe its impact on the properties of clay loam (CL), sandy clay loam (SCL) and sandy loam (SL) soils and the growth of corn (Zea mays indentata L.) and wheat (Triticum aestivum ssp./vulgare Vill. v. lutescens) under greenhouse conditions. The diluted TP solutions (1:500, 1:1000 and 1:2000) were sprayed onto the soil surfaces. The wheat growth increased for CL and SCL with the application of TP at 1:1000. The highest dry weights were detected with 1:500 TP and corn in all the soils. Penetration resistance of CL containing corn increased with increasing TP concentration. TP was also effective in improving the aggregate stability for CL but not for the other soils. Catalase enzyme activity (CEA), soil evolution (SE) and the total aerobic bacterial population (TABP) were significantly increased (P<0.05) by spraying TP at 1:1000 onto CL.

Agriculture↗

Transient splenial lesion of corpus callosum associated with antiepileptic drug: conventional and diffusion-weighted magnetic resonance images.

Transient focal lesions of splenium of corpus callosum can be seen as a component of many central nervous system diseases, including antiepileptic drug toxicity. The conventional magnetic resonance (MR) findings of the disease are characteristic and include ovoid lesions with high signal intensity at T2-weighted MRI. Limited information exists about the diffusion-weighted MRI characteristics of these lesions vanishing completely after a period of time. We examined the conventional, FLAIR, and diffusion-weighted MR images of a patient complaining of depressive mood and anxiety disorder after 1 year receiving antiepileptic medication.

Adolescent↗

Rate of metoclopramide infusion affects the severity and incidence of akathisia.

OBJECTIVE: To investigate the effect of the rate of metoclopramide infusion on akathisia incidence, severity, onset of symptoms, and duration in patients with headache, and/or nausea/vomiting in the emergency department (ED) setting. METHODS: Prospective, double blind, randomised clinical study comparing two rates of intravenous infusion of metoclopramide over a period of six months at a tertiary university hospital ED. RESULTS: A total of 300 patients presented to the ED met the inclusion criteria: 151 (50.3%) with nausea/vomiting, 108 (36%) with headache, and 41 (13.7%) with headache and nausea/vomiting. Of these, 154 patients (51.3%) were given 10 mg metoclopramide as a slow intravenous infusion over 15 minutes plus placebo (SIG group) and 146 patients were given 10 mg metoclopramide intravenous bolus infusion over two minutes plus placebo (BIG group). Nine of the 154 patients in the SIG group (5.8%) had akathisia compared with 36/146 patients (24.7%) in the BIG group (p < 0.001, OR 5.273, 95% CI 2.43 to 11.403). Severe akathisia were observed in 13/45 (28.8%). The incidence of severe akathisia was significantly higher in the BIG group (30.5%; 11/36) than in the SIG group (22.2%; 2/9), p = 0.009. Metoclopramide successfully relieved the presenting symptom(s) of 137/146 (90.8%) and 139/154 (90.2%) patients in the BIG and SIG groups, respectively. CONCLUSIONS: This study suggests that slowing the rate of infusion of metoclopramide is an effective strategy for reducing the incidence of akathisia in patients with headache, and/or nausea/vomiting in ED.

Adult↗

Glioblastoma multiforme with atypical diffusion-weighted MR findings.

The aim of this study is to review the diffusion-weighted MRI findings of glioblastomas, to investigate those with atypical characteristics and to emphasise the reasons responsible for the atypical features on diffusion-weighted MR images. 48 cases of histologically proven glioblastomas were included in this study. In addition to conventional sequences of routine tumour protocol, diffusion-weighted MRI with spin-echo echo-planar sequence was performed. The cystic-necrotic components of the lesions, according to the conventional sequences, were determined on the diffusion-weighted MR images and were classified as typical or atypical. The presence of high signal intensity was accepted as an atypical feature while low signal intensity was accepted as typical. The apparent diffusion coefficient (ADC) values of the cystic components were calculated. The statistical significance of the typical and atypical glioblastomas was evaluated with the students t-test. In six of the cases apparent high signal intensity in diffusion weighted MR images was interpreted. In three cases the high signal intensity occupied all of the cystic component and in the other three most of the cystic component. The ADC values of the lesions varied between 0.86 x 10(-3) mm(2) s(-1) and 1.39 x 10(-3) mm(2) s(-1) (mean value 1.06+/-0.17 x 10(-3) mm(2) s(-1)). In 42 of the lesions the cystic-necrotic component demonstrated low signal intensity and the ADC values varied between 1.56 x 10(-3) mm(2) s(-1) and 3.32 x 10(-3) mm(2) s(-1) (mean value 2.36+/-0.46 x 10(-3) mm(2) s(-1)). The difference between ADC values of atypical and typical lesions was statistically significant (p<0.001). The vast majority of glioblastomas do not exhibit restricted diffusion in diffusion-weighted MRI, but some of them display homogeneous or heterogeneous high signal intensity and decrease of ADC values. Diffusion-weighted MRI alone is not helpful in the differentiation of malignant tumours from abscesses with low ADC values and similar conventional MRI findings.

Adult↗

Breast conserving surgery after primary chemotherapy in locally advanced breast cancer.

PURPOSE: Primary chemotherapy is being given in the treatment of locally advanced breast cancers (LABC), but a major concern is local recurrence after therapy. The aim of this study was to assess the role of breast conserving surgery (BCS) in patients with locally advanced breast cancer. MATERIAL AND METHODS: Twenty-eight patients, presenting LABC (T any, N 012, M0) were treated with primary chemotherapy comprising of cyclophosphamide, doxorubicin and fluorouracil and then BCS followed by radiotherapy were examined between the years 1992-2002 retrospectively. Before neoadjuvant chemotherapy, seven patients (25%) were Stage IIB, 19 patients (68%) Stage IIIA and two patients (7%) Stage IIIB. Survival times and curves were established according to the Kaplan-Meier method and compared by means of the log-rank test. The chi-square test and log rank test were performed for univariate statistical analysis of each prognostic factor. P values in multivariate analysis were carried out by the Cox's proportional hazards regression model. All p values were two-sided in tests and p values <0.05 were considered significant. RESULTS: Clinical down staging was obtained in 25 (89%) of patients. Three (11%) patients had complete clinical response, 22 (78%) patients with partial response and 3 (11%) had stable disease. The primary tumour could not be palpated after chemotherapy in 6 (21%) of 28 patients presenting with palpable mass, therefore needle localization was performed for BCS. Median follow-up was 51.9 months (ranging 10 to 118 months). Local recurrence was detected in 4 (14%) patients. Distant metastasis developed in 5 (18%) patients. Three of the patients died of distant metastases and two of them are alive at 49 months. Five-year survival rate was 66%. Statistically, there were no significant factors in terms of local recurrence. Histological grade and menopause status were significantly associated with overall survival (p = 0.018) and nuclear grade was the one significant factor on distant disease-free survival in univariate analysis (p = 0.006). In multivariate analysis, there were no significant factors in terms of overall and distant disease-free survival CONCLUSIONS: Negative margin is more important than the clinical and histological parameters, such as pretreatment stage, clinical response rate, ER and PR in terms of local recurrence. BCS can be performed safely by achieving free surgical margin in patients who have small sized tumour and with either N2 axillary involvement or skin invasion.

Adult↗

Laparoscopic treatment of mesenteric cysts.

Mesenteric cysts are rare intraabdominal tumors. We review the diagnosis, laparoscopic management, patient's outcome and follow-up of evaluation for three cases of mesenteric cyst that presented to Istanbul University, Istanbul Medical School, Department of Surgery, from 1999 to 2002. All of the patients presented with nonspecific abdominal symptoms such as constipation, abdominal discomfort, and anorexia. Preoperative evaluation for differentiating mesenteric cyst from malignancy is made by abdominal ultrasound and computed tomography. The procedure was completed laparoscopically using three trocars in three patients. In one patient retroperitoneal resection was performed. There were no intraoperative or postoperative complications. The follow-up periods ranged from 6 to 36 months, and there were no recurrences. Currently, the surgical treatment of mesenteric cyst should be performed by laparoscopy, which offers significant advantages in terms of reduced morbidity and hospital stay. For appropriate cases in which cyst arises from mesenterium of colon, the retroperitoneal approach should be applied.

Adult↗

Treatment of nasolacrimal duct obstruction in adults with polyurethane stent.

PURPOSE: To evaluate the efficacy of polyurethane nasolacrimal duct stents in the treatment of epiphora resulting from primary acquired nasolacrimal duct obstruction in adults. MATERIALS AND METHODS: In 25 patients (21 women and four men with mean age of 44 years, range 20 to 74 years) with nasolacrimal duct obstruction, 28 hollow polyurethane stents designed by Song and associates were placed under fluoroscopic guidance. The obstruction was complete in 20 lacrimal drainage systems and partial in eight. The lacrimal sac size was normal or large on dacryocystogram in all lacrimal drainage systems. A Ritleng probe was introduced through the upper punctum and advanced past the obstruction. A guide wire with a flexible tip was then introduced through the probe, over which the stent was advanced in retrograde fashion and placed into the lacrimal sac and nasolacrimal duct. Clinical success was defined by the demonstration of a completely patent lacrimal drainage pathway through saline irrigation and no or minimal complaint of epiphora. RESULTS: Stent placement was technically successful in 26 of 28 lacrimal drainage systems (93%). The mean time of fluoroscopy screening was 3.2 minutes (range, 1.4 to 5.8 minutes). The overall success rate was 82% (23 of 28 lacrimal drainage systems). Two stents were completely occluded. In one lacrimal drainage system with minimal epiphora, the stented drainage pathway was partially occluded. The patients were followed up from 4 to 22 months (mean, 7.2 months). CONCLUSIONS: Retrograde placement of a hollow polyurethane nasolacrimal duct stent is a technique that is simple and well tolerated by patients. This method achieves a high success rate and may be suggested as a nonsurgical procedure for adults with primary nasolacrimal duct obstruction and proper lacrimal sac size. The Ritleng probe facilitates the procedure.

Adult↗

Treatment of obstructive epiphora in adults by balloon dacryocystoplasty.

AIMS: To determine the efficacy of dacryocystoplasty with balloon dilatation in the treatment of complete and partial obstruction of the lacrimal drainage system. METHODS: The procedure was performed on 26 patients with epiphora due to complete (n=16) or partial (n=10) obstruction of the lacrimal drainage system. A flexible tipped guide wire was introduced through the superior canaliculus into the inferior meatus and manipulated out of the nasal cavity. A 3 mm balloon was then introduced in a retrograde direction over the guide wire and dilated at the obstruction site. RESULTS: The procedure was technically successful in all patients with partial obstruction, but unsuccessful in four of 16 cases with complete obstruction. Reobstruction occurred in eight of 12 patients with complete obstruction, and in five of 10 patients with partial obstruction. The overall success rate was 25% for complete and 50% for partial obstructions. The mean follow up was 14 months (8-37 months). CONCLUSION: Although the balloon dacryocystoplasty is a simple and minimally invasive technique, the outcome from our study indicates that it is not advisable for treatment of complete obstruction of the lacrimal drainage system. Balloon dilatation may prove suitable for the treatment of patients with partial obstruction below the level of the lacrimal sac, especially in those who are poor candidates for surgery, or who do not wish to undertake dacryocystorhinostomy. Even in the partial obstruction group the success rate was only 50%, so that further modification to the technique and controlled studies are likely to be required before it could be recommended for general use.

Adolescent↗

Polyarteritis nodosa presenting with hemobilia and intestinal hemorrhage.

Polyarteritis nodosa is a multisystem disease primarily involving the small and medium-sized vessels. Prognosis depends on the presence and severity of visceral involvement. Thrombosis and aneurysm formation commonly occur in kidney and gastrointestinal tract. Although hepatic involvement is also common, hepatic aneurysmal rupture with intrahepatic or perihepatic hematoma formation is infrequent. Hemobilia secondary to aneurysmal rupture is a very rare condition. We present a case of polyarteritis nodosa accompanied by hemobilia and intestinal hemorrhage secondary to hepatic and mesenteric aneurysmal rupture.

Adolescent↗

Solid and papillary epithelial neoplasm of the pancreas: CT and MR findings.

Solid and papillary epithelial neoplasm of the pancreas is a very rare low-grade malignant neoplasm with only 126 cases reported in the literature and seen mostly in young female patients. Surgical excision means cure in cases before malignant degeneration developed. Its characteristic findings are typical location in the tail of the pancreas, peripheral capsule formation, hypodensity on CT images, and hyperintense internal signal characteristics on T1-weighted MR images secondary to hemorrhage and accumulation of methemoglobine molecule. These findings are enough for the preoperative diagnosis that may lead to early surgery and cure. We present the CT and MR findings of this very rare neoplasm in a case report.

Adult↗

Primary tonsillar tuberculosis: a case report.

A 67-year-old man with an enlarged left tonsil underwent a tonsillectomy for the suspicion of malignancy. He had had a dental extraction six months earlier. Clinical and histopathological investigations established the diagnosis of primary tonsillar tuberculosis.

Aged↗

Surgical treatment of hepatic hydatid disease.

The results of surgery in 38 patients with hepatic hydatid disease are described. Cystectomy was done in four patients with small peripheral cysts. For them the mean postoperative stay was 8.2 days. Partial cystectomy, introflexion and omentoplasty were performed in 28 patients with uncomplicated large cysts. The mean postoperative stay for these patients was 8.6 days. One patient in this group died of massive hemorrhage and disseminated intravascular coagulation. Exploration of the common bile duct and choledochoduodenostomy were required in three patients who had large cysts complicated by rupture into the biliary tree. This complication resulted in a mean postoperative stay of 11.5 days. Three patients who had cysts complicated by pyogenic infection were treated with tube drainage. They were discharged with their tubes in place after a mean hospital stay of 26.5 days. Hydrogen peroxide 10% was used as a scolicidal agent and was successful in preventing dissemination. All patients underwent ultrasonography 3 months after surgery, and 28 (74%) were followed up by annual examination. There was no recurrence after a mean follow-up of 2.7 years. The results suggest that surgical treatment of hepatic hydatid disease should be governed by the size, location and complications of the cyst. The combination of partial cystectomy, introflexion and omentoplasty was safe and effective therapy for patients with large hepatic cysts uncomplicated by pyogenic infection.

Adolescent↗

The role of sentinel lymph node biopsy with blue dye alone in breast cancer patients with excisional biopsy.

PURPOSE: Sentinel lymph node biopsy (SLNB) appears to offer an excellent alternative method to routine axillary lymph node dissection for staging patients with breast cancer. The aim of this study is to evaluate the effect of excisional biopsy on identification and false negative rate of sentinel lymph node biopsy with blue dye alone in breast cancer patients with clinically negative axilla. MATERIAL AND METHODS: From March 1998 to March 2003, 266 consecutive sentinel lymph node biopsies (SLNB) were performed using isosulfan blue dye alone. Patients were divided into two groups. One hundred and four patients (39.1%) had previously undergone an excisional biopsy (Group I); in 162 patients (60.9%), pre-operative diagnosis was obtained by either fine-needle aspiration biopsy (FNAB) or core biopsy (Group II). Following sentinel lymph node biopsy, all patients had axillary lymph node dissection (ALND). Data concerning patients, sentinel lymph nodes and the status of the axilla were collected and compared using Fisher's exact test. A p value of less than 0.05 was considered statistically significant. RESULTS: The sentinel lymph node was successfully identified by blue dye in 94.3% (251/266) of patients. Mean lymph nodes removed from the axilla was 19 (range 11-36) and the mean number of sentinel nodes was 2 (range 1-5). The identification and false negative rate were unrelated to size, type or location of the tumour, or a previous surgical biopsy. CONCLUSIONS: SLNB with blue dye for evaluation of the axilla is a rapid and accurate technique that provides increased efficacy in the detection of lymphatic metastasis when careful pathologic evaluation with serial sections is performed. The risk-benefit analysis of lymphatic mapping with blue dye provides improvement in staging, with reduced morbidity and hospital stay, and the elimination of general anaesthesia. The technique may also be used safely and accurately in breast cancer patients with excisional biopsy.

Biopsy, Needle↗