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Biomedical subjects

Erkan Yilmaz

Publications and source records attributed to Erkan Yilmaz.

At least 19 recordsLinked to original sources

Chemical chaperones reduce ER stress and restore glucose homeostasis in a mouse model of type 2 diabetes.

Endoplasmic reticulum (ER) stress is a key link between obesity, insulin resistance, and type 2 diabetes. Here, we provide evidence that this mechanistic link can be exploited for therapeutic purposes with orally active chemical chaperones. 4-Phenyl butyric acid and taurine-conjugated ursodeoxycholic acid alleviated ER stress in cells and whole animals. Treatment of obese and diabetic mice with these compounds resulted in normalization of hyperglycemia, restoration of systemic insulin sensitivity, resolution of fatty liver disease, and enhancement of insulin action in liver, muscle, and adipose tissues. Our results demonstrate that chemical chaperones enhance the adaptive capacity of the ER and act as potent antidiabetic modalities with potential application in the treatment of type 2 diabetes.

Adipose Tissue↗

Anomalous origin of the right vertebral artery from the ascending aorta in the presence of an aberrant right subclavian artery.

We present a case of a 63-year-old man who was admitted to the hospital due to an acute coronary syndrome. Angiographic and magnetic resonance angiography examination showed an abnormal right vertebral artery originating from the ascending aorta, just above the left coronary sinus Valsalva in addition to aberrant retro-esophageal right subclavian artery. The variations and the incidence of various abnormal origins of the right vertebral artery are also reviewed.

Angina, Unstable↗

[Pseudomonas aeruginosa colonisation in bronchiectatic patients and clinical reflections].

Bronchiectasis is characterized with irreversible dilatation according to destruction of epithelium, elastic and muscular layer. Most important cause of bronchiectasis is chronic bacterial infections. Pseudomonas aeruginosa colonisation is frequently seen in bronchiectatic patients. We aimed to find out P. aeruginosa colonisation frequency and clinical, radiological and spirometric reflections due to colonisation. We analysed 83 cases retrospectively. Mean age was 58.2 and 54.2% of them were female. Bronchiectasis were localised 19.3% in left lung, 19.3% right and 61.4% bilaterally. 29 (35.8%) normal, 28 (34.6%) obstructive, 7 (8.6%) restrictive, 17 (21%) mixed type disorders are detected in spirometric measures. Sputum culture performed in 50 cases. No microorganism colonisation determined in 30 (60%) cases, P. aeruginosa colonisation 16 (32%), Haemophilus influenzae 2 (4%), 1 (2%) Streptococcus pneumoniae and Proteus mirabilis 1 (2%) cases. P. aeruginosa colonisation determined more frequent in males (p<0.05). No significant correlation detected between colonisation and age or smoking habits (p>0.05). In cases with colonisation; clubbing and hemoptysis were significantly frequent (p<0.05). Only peribronchial thickening was significantly correlated with colonisation in radiological findings (p<0.05). In blood gase analysis PaO2, oxygen saturation were lower and PaCO2 higher in cases colonised with P. aeruginosa but it was not statisticaly significant (p>0.05). Hospitalization rate was higher in P. aeruginosa colonised cases (p>0.05). It is an important problem about mortality because of higher hemoptysis and hospitalisation requirement rate in P. aeruginosa colonised cases.

Adult↗

Endoplasmic reticulum stress links obesity, insulin action, and type 2 diabetes.

Obesity contributes to the development of type 2 diabetes, but the underlying mechanisms are poorly understood. Using cell culture and mouse models, we show that obesity causes endoplasmic reticulum (ER) stress. This stress in turn leads to suppression of insulin receptor signaling through hyperactivation of c-Jun N-terminal kinase (JNK) and subsequent serine phosphorylation of insulin receptor substrate-1 (IRS-1). Mice deficient in X-box-binding protein-1 (XBP-1), a transcription factor that modulates the ER stress response, develop insulin resistance. These findings demonstrate that ER stress is a central feature of peripheral insulin resistance and type 2 diabetes at the molecular, cellular, and organismal levels. Pharmacologic manipulation of this pathway may offer novel opportunities for treating these common diseases.

Adipose Tissue↗

The evaluation of the proximal tibiofibular joint for patients with lateral knee pain.

In contrast to important functions of the proximal tibiofibular joint (PTFJ), there appear a few clinical and radiological studies concerning the PTFJ pathologies. Although almost all of the joints have been investigated in detail by MRI, review of the literature reveals none on the pathologies of PTFJ. Thirty-eight knees of 32 patients with lateral knee pain were evaluated clinically and radiologically. All had tenderness over the PTFJ and lateral hamstring tightness. MRI examination revealed effusion of the PTFJ in 22 knees and partial ruptures of anterior or posterior tibiofibular ligament, lateral collateral ligament or biceps femoris tendon in 25 knees. All patients were treated by manipulative physiotherapy of the PTFJ and strengthening and stretching exercises of the surrounding structures. All patients were followed-up 12-36 months (mean 28 months) after the treatment protocol, and complete relief of the symptoms was recorded in 28 of the 38 knees. Although spontaneous pain was not present in five patients, there was tenderness over the PTFJ by palpation. No change in the symptoms was recorded in five patients. These results suggest that PTFJ pathologies should be kept in mind in the evaluation of lateral knee pain and MRI examination provides useful information.

Adolescent↗

A case of a bronchogenic cyst in a rare location.

Bronchogenic cysts occur as a result of a developmental fault during the division and budding of the tracheobronchial tree in the embryonic period. They are usually located in the mediastinum and intrapulmonary regions. They may cause serious respiratory distress in childhood; they present less commonly in adults and often present with a variety of symptoms, including recurrent infections. We report the case of an adult female patient who presented with recurrent pulmonary infections and swelling of the neck because of a bronchogenic cyst that was unusually located in the cervical region.

Bronchogenic Cyst↗

Familial acromegaly: a familial report and review of the literature.

Familial acromegaly without features of multiple endocrine neoplasie type 1 (MEN 1) is an exceptional clinical entity. We report in this article three cases of acromegaly due to pituitary macroadenomas without any other endocrinopathy in a family. A 31-year-old woman (subject A) and her 34-year-old sister (subject B) with elevated basal rolactin (PRL) levels, elevated growth hormone (GH) levels during the oral glucose tolerance test (OGTT) and a pituitary adenoma in Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) were diagnosed as acromegaly. Subject A was treated only with radiotherapy and Lysuride. Subject B underwent transsphenoidal microsurgical extirpation 15 years ago. 11 years later her 24-year-old son (subject C) also presented with typical signs of acromegaly, elevated basal PRL level and elevated GH levels during OGTT. A pituitary macroadenoma was identified by MRI and he also underwent transsphenoidal adenomectomy. Pathology reports confirmed the diagnosis of GH-secreting pituitary adenoma in subject B and C. Immunocytochemistry revealed that tumours of subject B (> 20% of tumour cells) and C (> 50% of tumour cells) were positive for GH. Tumours of subject B (> 10% of tumour cells) and C (> 50% of tumour cells) also exhibited immunoreactivity for PRL. On investigation of histocompatibility antigens, it was observed that the subject A, B, and C shared the same haplotypes [HLA A24(9), HLA B13(6), HLA B35, HLA DQ7(3), HLA DR13(6)] and so it is very possible that investigation of HLA antigens in patients with pituitary tumour, contributes to better identification of its familial nature and frequency. Here we describe an acromegaly family and the distributions of HLA antigens.

Acromegaly↗

Disseminated pulmonary candidiasis complicating hyperimmunoglobulin E (Job's) syndrome.

Hyperimmunoglobulin E (Job's) syndrome is a rare disease characterized by recurrent pneumonia and sinusitis, pneumatoceles, chronic dermatitis, and elevated serum levels of immunoglobulin E. In this report, the author presents a case of disseminated pulmonary candidiasis in a young man with hyperimmunoglobulin E syndrome. His chest radiograph showed reticulonodular opacities in both lungs. Computed tomography scans revealed multiple pulmonary nodules and hilar and mediastinal enlarged lymph nodes.

Adult↗

The case of a cyst hydatid localized within the interatrial septum.

The ratio of cardiac involvement of Echinoccocus granulosus is 0.02-2% and although seen rarely, involvement of the interatrial septum has also been reported in the published literature. The present case was a 19-year-old male university student admitted to hospital with complaints of headache and dizziness. Computerized tomography of the cranium revealed a cystic mass located at the frontal region and enucleation of the cyst was performed during surgery. A cystic lesion 5 x 4 cm in size was detected within the interatrial septum on two-dimensional transthoracic echocardiography during the postoperative period and the patient was referred to our clinic. Open heart surgery was performed and a hydatid cyst that involved the interatrial septum was enucleated. The cyst wall was sutured to the interatrial septum. No complications developed during the postoperative period. The patient was discharged on the fifth day of hospitalization and medical therapy was started with albendazole.

Adult↗

Tuberculous ileitis in a renal transplant recipient with familial Mediterranean fever: Gray-scale and power Doppler sonographic findings.

The ileocecal area is the most common site of involvement of intestinal tuberculosis. We report the case of a 26-year-old renal transplant recipient with familial Mediterranean fever who developed tuberculous ileitis. Gray-scale sonography and CT showed circumferential thickening of the bowel wall and enlargement of the mesenteric lymph nodes. Power Doppler sonography revealed markedly increased vascularity in the wall of the affected ileal segment and in the mesenteric nodes. Some nodes had no flow at the center owing to caseation necrosis, a finding consistent with the diagnosis of tuberculous ileitis. Colonoscopy was performed, and histopathologic examination of biopsy specimens revealed acute inflammatory changes. Cultures of the specimens confirmed the presence of Mycobacterium tuberculosis. We conclude that findings on power Doppler sonography may support a diagnosis of tuberculous ileitis and avoid clinical mismanagement.

Adult↗

The efficacy of helical CT in the diagnosis of small bowel obstruction.

OBJECTIVE: To evaluate the usefulness and reliability of helical computed tomography (CT) for patients with small bowel obstruction. METHODS AND MATERIAL: Helical CT findings of 41 patients were evaluated prospectively on the basis of the presence and the cause of obstruction, and the presence of strangulation. RESULTS: In the determination of the cause of the obstruction sensitivity and specificity of CT were 84 and 90%, respectively. Of the 19 patients undergoing surgery, 6 had strangulation and were correctly identified by CT. CONCLUSION: Helical CT is an accurate method in the detection of small bowel obstruction, especially for evaluating the cause and vascular complications of obstruction.

Contrast Media↗

The proximal tibiofibular joint: an anatomic study.

In the first stage of the current study, 14 fresh specimens from above-the-knee amputations were examined by magnetic resonance imaging arthrography. In the second part of the study, these amputation specimens and 38 embalmed knees from cadavers were dissected. The types of the joint and insertion of the biceps femoris tendon and the other structures were observed. Of 14 fresh specimens from above-the-knee amputations examined by magnetic resonance imaging arthrography, nine had a clear communication between the proximal tibiofibular joint and the knee. It was difficult to distinguish the anterior tibiofibular ligament in 30 specimens as a separate band because it was fused intimately with the biceps femoris tendon. Of these specimens, 24 had an oblique type of joint. Because of this communication, the proximal tibiofibular joint might be construed as the fourth compartment of the knee to explain subtle knee problems.

Amputation, Surgical↗

Bone mineral density reference values in the normal female and male population of Izmir, Turkey.

In this study we aimed to establish the dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) reference values of healthy Turkish women and men residing in Izmir, western Turkey. We examined 347 women and 119 men (age range 20-80 years) who did not have any known risk factor that might affect bone mass. The BMD measurements were performed by Hologic QDR 4500 W Elite DXA instrument from the lumbar spine (L1-L4) and non-dominant hip. In women the mean BMD (g/cm(2))+/-standard deviation (SD) of the normal reference group between 20 and 39 years of age was 0.963+/-0.121 g/cm(2) in the lumbar spine and 0.891+/-0.119 g/cm(2) in total femoral region. The percentages of annual and total BMD losses in women between 30 and 80 years of age were 0.74 and 29% at spinal level and 0.65 and 26% in femoral region, respectively. The average BMD of the normal men's group between 20 and 39 years of age was 0.996+/-0.111 g/cm(2) in the lumbar spine and 1.025+/-0.110 g/cm(2) in femoral region. The percentages of annual and total BMD losses were 0.33 and 13% at spinal level and 0.50 and 20% in femoral region, respectively. In conclusion, like the values reported from mid-Anatolian region of Turkey, the BMD values of Turkish women and men residing in Izmir, western Anatolia, are also lower than in most European countries with regard to US and preinstalled Hologic values.

Absorptiometry, Photon↗

An association between mesial temporal lobe epilepsy with hippocampal sclerosis and human leukocyte antigens.

PURPOSE: Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is one of the medically intractable epilepsies that may be remediable with surgery. Although the pathogenesis of HS still remains obscure, genetics may play a role as a predisposing factor, with the genetically controlled immune system as one of its aspects. Our aim in this study was to investigate whether there is any association between human leukocyte antigens (HLAs) that are related to chromosome 6 and this specific type of epilepsy. METHODS: HLA class I and II typing were performed with the microlymphocytotoxicity method on 65 Turkish patients with MTLE-HS and on 184 healthy controls. RESULTS: Our study revealed a significantly high frequency of class II antigens HLA-DQ2, -DR4, and -DR7 alleles and the combination of HLA-DR4-DQ2, and DR7-DQ2 alleles. CONCLUSIONS: The HLA alleles that occur with increased frequency in many HLA- associated conditions appear to serve as risk factors that increase susceptibility but are not essential for disease expression. Our data support the role of genetic factors in the development of HS, possibly related to early childhood events that may act as a trigger factor to initiate the cascade in genetically prone patients with specific HLA types to give rise to MTLE eventually.

Adolescent↗

Differentiation of phyllodes tumors versus fibroadenomas.

PURPOSE: To determine if mammographic and sonographic findings allow discrimination between phyllodes tumor and large sized fibroadenoma, which mimic each other in the clinical, radiologic and histopathologic appearances. MATERIAL AND METHODS: Thirty-one histopathologically proven masses including 12 phyllodes tumors and 19 fibroadenomas 3 cm or greater in diameter were compared. In total 28 women were retrospectively evaluated by mammography and pre-operative sonography. RESULTS: Mammography revealed a high-density mass compared with surrounding fibroglandular breast tissue to be present in 9 of the 12 (75%) phyllodes tumors and 7 of the 19 (37%) fibroadenomas. At sonography a mass, which had a round or lobulated shape, marked posterior acoustic enhancement and intramural cystic areas, were statistically significantly more likely to be phyllodes tumors than fibroadenomas. None of the other mammographic or sonographic characteristics proved to be useful in differentiating phyllodes tumors and fibroadenomas. CONCLUSION: Although masses of high density at mammography, circumscribed border associated with posterior acoustic enhancement and internal cystic areas at sonography should suggest the diagnosis of phyllodes tumors rather than large sized fibroadenomas, there was a substantial overlap in the mammographic and sonographic characteristics of these two tumors. Therefore, an excisional biopsy would be necessary for equivocal masses.

Adult↗