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Altan Yildiz

Publications and source records attributed to Altan Yildiz.

At least 19 recordsLinked to original sources
PubMed2006

Biomechanical evaluation in osteoporosis: ovariectomized rat model.

The aim of our study was to investigate the effects of ovariectomy on rat femur biomechanical parameters. Bone mineral density (BMD) and histological investigation were also evaluated. Fourteen female Sprague-Dawley rats (seven ovariectomized, seven control) were used. BMD was measured by dual-energy X-ray absorbsiometry. Bone biomechanical parameters were measured in femoral midshaft with tensile test using a biomaterial testing machine and maximum load, stiffness, energy absorption capacity (structural properties), ultimate stress, ultimate strain, and elastic modulus (material properties) were calculated. Diaphyseal cortical bone thickness was measured by using histological method. The ovariectomized (OVX) rat femur's BMD was 14% lower than control rats (p=0.006). Mean maximum load was 55% less than the control group's (p=0.0001). Stiffness was 72% less in OVX rats (p=0.05). Femurs of rats with OVX had 32% less absorbed energy than controls (p=0.09). From the stress-strain curve ultimate stress, ultimate strain and elastic modulus was calculated. Elastic modulus was 53% less than controls (p=0.05). Ultimate stress decreased 21% in OVX rats (p=0.097). Ultimate strain was 25% less than controls in OVX rats. Cortical thickness was significantly decreased in OVX rats than in controls (p<0.05). In conclusion, femur biomechanical parameters are decreased in osteoporosis.

Animals↗
PubMed2006

Low-exposure cadmium is more toxic on osteoporotic rat femoral bone: mechanical, biochemical, and histopathological evaluation.

This study aimed to investigate the effects of low-exposure Cd on normal and osteoporotic bone. For this purpose, 12-week-old Sprague-Dawley female rats were assigned randomly to a control group, a Cd group, and an ovariectomy (OVX)+Cd group. OVX+Cd rats underwent bilateral ovariectomy via ventral incision. Twelve weeks after ovariectomy, cadmium chloride (CdCl(2)) was given to rats (Cd and OVX+Cd groups) as intraperitoneal (ip) injection of 0.5mg/kg three times a week for 18 weeks and distilled water was given to control group via ip route for 18 weeks. Bone mineral density (BMD) was measured at mid-diaphysis femoral region by dual-energy X-ray absorbsiometry. Cross-sectional area of the femoral shaft was evaluated by computerized tomography. Biomechanical measurements were performed at the mid-diaphysis of the left femur. Collagen fibers were evaluated at light microscopic level. BMD, cortical thickness, cortical area, and femur length were not changed in Cd and OVX+Cd groups in comparision to controls. In the OVX+Cd group, strength, displacement, energy, stress, strain, and toughness were significantly lower than those of the control group. The Cd concentration of bone was significantly increased in the OVX+Cd group compared to that in the control group. Collagen fiber intensity was decreased in all groups except control group. The results of the present study indicate that the administration of low-dose Cd does not affect normal bone biomechanical parameters, but it has a significant effect on osteoporotic bone.

Animals↗
PubMed2005

Inspiratory and expiratory HRCT findings in Behçet's disease and correlation with pulmonary function tests.

PURPOSE: The purpose of our study was to describe the pulmonary parenchymal changes of Behçet's disease using high-resolution computed tomography and to correlate them with pulmonary function tests. MATERIALS AND METHODS: Thirty-four patients with Behçet's disease (18 men, 16 women), 3 of whom were symptomatic, were included as the study group. Four of 34 patients were smokers. Twenty asymptomatic volunteers (12 men, 8 women), 4 of whom were smokers, constituted the control group. The pulmonary function tests and high-resolution computed tomography were performed for both groups. RESULTS: Inspiratory high-resolution computed tomography findings were abnormal in nine patients (26.5%) of the study group. In eight patients, there were multiple abnormalities, whereas one patient had only one abnormality. Pleural thickening and irregularities, major fissure thickening, emphysematous changes, bronchiectasis, parenchymal bands, and irregular densities, and parenchymal nodules were the encountered abnormalities. Inspiratory high-resolution computed tomography scans were normal in the control group. On expiratory scans, there was statistically significant difference between study group and control group when air trapping, especially grades 3 and 4, was compared (P<0.01). Pulmonary function tests of both the study and the control groups were in normal ranges, and there was no statistically significant difference between the two groups according to pulmonary function tests (P>0.05). DISCUSSION AND CONCLUSION: High-resolution computed tomography is sensitive in the demonstration of pulmonary changes in patients with Behçet's disease. End-expiratory high-resolution computed tomography examination is very useful and necessary to show the presence of air trapping, thus the presence of small airway disease, even if the patient is asymptomatic or has normal pulmonary function tests.

Adolescent↗
PubMed2004

Actinomycosis of the middle turbinate: an unusual cause of nasal obstruction.

Actinomycosis is a rare chronic infectious disease caused by Actinomyces israelii, which is an anaerobic filamentous, gram-positive saprophyte organism of the oral cavity. Historically, these bacteria were known as fungi because of their light microscopic appearance. Actinomycosis consists of three different forms: cervico-facial (the most common form), abdominal and pulmonothoracic. It commonly involves the head and neck region including the mandible, paranasal sinuses, lacrimal gland, parotid gland and orbit. Poor oral hygiene and dental diseases have been known to be the source of actinomycosis. Actinomycosis is diagnosed with positive culture or detecting actinomyces colonies and sulfur granules in histopathologic specimens. The treatment of choice is surgical excision of the lesion and long-term penicillin therapy. Actinomycosis of the internal nose is extremely rare. There was only one nasal septum actinomycosis reported in the English literature, but there was no lateral nasal wall actiomycosis regarding the turbinate. Therefore, actinomycosis should not be overlooked for the differential diagnosis of intra-nasal lesions for the initiation of appropriate and early treatment.

Actinomyces↗
PubMed2004

Two episodes of anuria and acute pulmonary edema in a losartan-treated patient with solitary kidney.

Atherosclerotic renal artery stenosis (RAS) is an increasingly important cause of end-stage kidney disease, and may cause hypertension, progressive renal failure, and recurrent pulmonary edema. Herein, we report two episodes of anuria and acute pulmonary edema associated with losartan treatment in a hypertensive patient with preexisting severe renal artery stenosis in a solitary kidney. After successful percutaneous renal balloon angioplasty procedure, urine flow was started immediately, despite 10 days of anuria. Blood pressure measurements were still at acceptable levels with a low dose Beta blocker, and serum creatinine levels were normal even after eight months. PTRA should be done in such patients, even with prolonged anuria. Physicians who recommend angiotensin receptor blockers in patients with RAS, especially in patients wih hypovolemia or a solitary kidney, should be careful about this complication.

Adult↗
PubMed2004

Diagnostic value of renal parenchymal density difference on unenhanced helical computed tomography scan in acutely obstructing ureteral stone disease.

OBJECTIVES: To evaluate the diagnostic value of the renal parenchymal density difference, detected using unenhanced helical computed tomography, as a secondary sign of acute obstruction due to a ureteral stone. METHODS: Fifty-five patients with acute flank pain, in whom a ureteral stone was detected on the symptomatic side using unenhanced helical computed tomography, and 22 control subjects with no urinary stone disease were included in this prospective study. Computed tomography was performed, starting from the upper poles of the kidneys down to the base of the urinary bladder. The renal parenchymal density was measured in the upper, middle, and lower portions of each kidney, and a mean value was calculated. The difference between the mean values of the two kidneys was used to predict the presence of an acutely obstructing ureteral stone. RESULTS: In 49 patients with a ureteral stone (89.1%), the difference between the parenchymal densities of the obstructed and nonobstructed kidneys was 5 Hounsfield units (HU) or greater and was lower on the obstructed side. In the remaining 6 patients (10.9%), the density difference was less than 5 HU but was still lower on the obstructed side. All subjects in the control group had a density difference of less than 5 HU. A renal parenchymal density difference of 5.0 HU or greater had 89.1% sensitivity, 100% specificity, 100% positive predictive value, 85.7% negative predictive value, and 93.4% accuracy in predicting the presence of an acute obstructing ureteral stone. CONCLUSIONS: These data suggest that the renal parenchymal density difference may be a valuable secondary sign of acute obstructing ureteral stone disease.

Acute Disease↗
PubMed2004

HRCT evaluation of the accessory fissures of the lung.

INTRODUCTION: The purpose of this study was to classify the accessory fissures of the lung and to assess their frequency by using high-resolution CT. METHODS AND PATIENTS: HRCT scans of 115 patients were prospectively reviewed. 1 mm thin sections were obtained at 10 mm intervals with a scan time of 1.9 s. The fissure and its relationship to the segmental bronchovascular structures were then evaluated on transverse sections. RESULTS: Forty-four accessory fissures were detected in 35 of 115 patients. The most common accessory fissure was the inferior accessory fissure (12%). The second most common accessory fissure was the left minor fissure (8%). The right superior accessory fissure (5%), the accessory fissure between the medial and lateral segments of the right middle lobe (5%), and the accessory fissure between the superior and inferior segments of the lingula (5%) were seen in equal frequencies. Also, intersegmental accessory fissures, namely the fissure between the anterobasal and laterobasal of both the right (1%) and the left (2%) lower lobes were detected. We found only one subsegmental accessory fissure. DISCUSSION AND CONCLUSION: The inferior accessory fissure and the left minor fissure were the most common accessory fissures in our study.

Adolescent↗
PubMed2004

The anterior center edge angle: a study of 102 volunteers.

OBJECTIVES: To measure the anterior center edge (VCE) angle that reflects anterior coverage of the femoral head. PATIENTS AND METHODS: False profile views of both hips of 102 volunteers, 23 male and 79 female, were taken between October 2000 and October 2001. Radiographs with evidence of degenerative hip disease and those with poor image quality were excluded from the study. This left 181 radiographs. RESULTS: An orthopedic surgeon and a radiologist used a standard protractor to examine each of the 181 radiographs twice, at an interval of 24 h. The mean VCE angle was 49.27 +/- 7.77 degrees (range, 24.75-68.75), a value different from those found in previous studies. No significant intraobserver or interobserver differences were found. CONCLUSIONS: Our findings may contribute to the determination of a new parameter for evaluating anterior femoral head covering. In patients with acetabular dysplasia and deficient anterior coverage, this parameter may prove useful for selecting patients for surgery, planning the procedure, and evaluating postoperative results.

Acetabulum↗
PubMed2003

A case of missing mitral valve leaflet: radiological detection.

Intravascular foreign bodies may be introduced into the circulation as a complication of minimally invasive or interventional techniques, or during cardiac valve surgery. Prosthetic heart valve leaflets have been rarely described as intravascular foreign bodies. Herein we report a case of prosthetic heart valve leaflet embolization to the aortic bifurcation with computed tomography and ultrasonography findings, and the importance of radiographic imaging in the localization of missing leaflet fragment is pointed out.

Aorta, Abdominal↗
PubMed2003

Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium.

The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case.

Amnesia↗
PubMed2003

Arachnoid granulations in the transverse sinuses of a patient with ocular melanoma.

Arachnoid granulations show typical imaging features that allow their distinction from dural sinus thrombosis and intrasinus tumor. These features include a mid-lateral transverse sinus location, focality, common adjacent entering superficial veins, origin of attachment, low density on computed tomography (CT), isointensity-hypointensity on T1-weighted magnetic resonance imaging (MRI) and hyperintensity on T2-weighted MRI. We report the CT and MRI findings of incidentally detected bilateral arachnoid granulations in the transverse sinuses of a patient with ocular melanoma.

Aged↗
PubMed2003

Involvement of the proximal tibiofibular joint in osteoarthritis of the knee.

This study was performed to evaluate the possible involvement of the proximal tibiofibular joint in primary osteoarthritis of the knee. A total of 40 patients with primary osteoarthritis of the knee who had magnetic resonance imaging scans were reexamined for proximal tibiofibular joint involvement. The patient was questioned if pain was present in the proximal tibiofibular joint while at rest, when walking and climbing stairs. Symptoms were evaluated by applying moderate compression over the proximal tibiofibular joint during active ankle and knee motions. Magnetic resonance imaging scans were reexamined by two radiologists. Three of the 40 patients had minimal or moderate pain in the proximal tibiofibular joint during stair-climbing and on clinical examination. Magnetic resonance imaging scans of these three patients revealed osteophyte or subchondral cyst formation, or both. Degenerative changes in the proximal tibiofibular joint may be evident in association with osteoarthritis of the knee and may result in lateral-sided pain at the knee.

Bone Cysts↗
PubMed2003

Diagnostic value of sonohysterography in the evaluation of submucosal fibroids and endometrial polyps.

AIMS: To evaluate the diagnostic value of sonohysterography in the evaluation of submucosal fibroids and endometrial polyps. METHODS: Thirty-two women whose preliminary transvaginal ultrasound suggested endometrial abnormality underwent sonohysterography. The findings were then compared with histopathological results. RESULTS: The sonohysterographic diagnosis was fibroid in seven patients, endometrial polyp in 23 patients and simple hyperplasia in two patients. Histopathological findings confirmed our diagnosis in all except three patients with endometrial polyps, who had normal secretory endometrium. Sonohysterography was found to have a sensitivity of 100%, a positive predictive value of 90% and diagnostic accuracy of 90.6%. CONCLUSION: Sonohysterography is a useful, minimally invasive and accurate technique to evaluate the pathologies involving endometrium and uterine cavity.

Adult↗
PubMed2003

Antrolithiasis: a retrospective study.

In this retrospective study, the computed tomography (CT) archives of paranasal sinus examinations were reviewed and three cases of antroliths are presented. The archives of paranasal sinus CT studies of 1957 patients (1023 females, 934 males, mean age 36.5 years) were surveyed. CT studies were performed using 3 mm collimation and interval in the coronal, axial or both coronal and axial planes. Three out of 1957 patients demonstrated antroliths, all in the left maxillary sinus. Associated sinusitis was detected in all three patients. Only one patient was operated. The chemical analysis of the antrolith revealed it to be a calcium oxalate stone. All the relevant literature is reviewed and only 25 other cases of true antrolithiasis were encountered. The clinical and radiological features of antroliths, as well as differential diagnosis were discussed. Antrolithiasis should be considered in any case of sinusitis, that does not respond to appropriate medical therapy.

Adult↗
PubMed2002

Disseminated pneumocephalus secondary to an unusual facial trauma.

Pneumocephalus can be secondary to a postintrathecal procedure, sinus fracture, basilar skull fracture, congenital skull defect, neoplasm, gas producing organism, barotrauma, neurosurgery, paranasal sinus surgery, mask or nasal continuous positive-airway pressure. Unusual facial traumas can also be rare causes of pneumocephalus. Here, we present such a case in whom an air compressor tip injury to both eyes led to the disseminated pneumocephalus. We report this rare case with the computed tomography findings and try to explain the possible mechanism of the pnemocephalus.

Adolescent↗
PubMed2002

Primary diffuse tracheobrochial amyloidosis: case report.

Respiratory amyloidosis is a rare disease that occurs in three forms: tracheobronchial, nodular parenchymal and diffuse parenchymal involment. Tracheobronchial amyloidosis is characterized by focal or diffuse deposition of amyloid in the submucosa of the trachea and proximal bronchi. Herein, we report a case of diffuse tracheobronchial amyloidosis with plain radiography and thorax computed tomography findings.

Amyloidosis↗
PubMed2002

Inferomedially projecting pneumatised secondary middle turbinate.

Secondary middle turbinate (SMT), a rare variation of the nasal cavity, is a bony projection covered by soft tissue that arises from the lateral nasal wall. It is almost always bilateral and usually projects superomedially without any ostiomeatal unit obstruction. Herein, we report a case of bilateral inferomedially projecting secondary middle turbinates, one of which is pneumatised and hypertrophied, resembling a large ethmoid bulla extending into the middle meatus. The recognition of this variation is important since it may predispose to inflammatory sinus disease, by narrowing the ostiomeatal unit.

Humans↗