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Biomedical subjects

S Erdem

Publications and source records attributed to S Erdem.

At least 37 records · Page 2Linked to original sources
PubMed1998

Subclinical cerebral involvement in Behcet's disease: a SPECT study.

Neurologic involvement has been reported in Behcet's disease (BD) with prevalence rates of 4-49%. Involvement of the central nervous system (CNS) usually follows systemic manifestations of BD by months to years, but as the initial future in only 5% of cases. The variance of the prevalence rates of neurologic involvement in BD raises the possibility of subclinical neurologic involvement. For the purpose of explaining the variance in the prevalence rates, 20 patients with BD, but without neurological symptoms and signs, were investigated by using cerebral single photon emission computed tomography (SPECT) which seems to be more convenient for BD than other scanners. A control group of patients with various diseases that were not expected to influence the cerebral blood flow was included. Brain magnetic resonance imaging (MRI) scans were performed in cases in which abnormal SPECT findings were obtained. Decreased and asymmetrical tracer uptakes were detected in 35% of patients with BD. MRI scans were normal in these patients. We concluded that functional imaging using SPECT may detect abnormalities at an initial stage prior to their progression to morphological damage detectable by MRI, and this imaging modality can be used even in cases which show no neurologic symptom to indicate the subclinical neurologic involvement.

Journal Article↗
PubMed1998

Fate of Schwann cells in CMT1A and HNPP: evidence for apoptosis.

The fate of Schwann cells in Charcot-Marie-Tooth (CMT) neuropathies was addressed in this study of nerve biopsies from patients with proven PMP22 duplications and deletions. In frozen sections, apoptotic nuclei were detected using the TUNEL method. In adjacent sections, anti-neurofilament 68kD antibody was used as an axonal marker, while the antibodies to NKH-1 and low-affinity nerve growth factor receptor P75NTR were used as Schwann cell markers. In addition, plastic sections were used to determine the densities of myelinated fibers and Schwann cell nuclei. In all biopsies from CMT1A, TUNEL-positive nuclei appeared in clusters. In adjacent sections, areas of TUNEL-positive nuclei matched with areas devoid of neurofilaments and NKH-1-positive Schwann cell silhouettes, suggesting that the apoptotic nuclei belonged to nonmyelinating Schwann cells. In addition, quantitative studies on plastic-embedded sections showed a significantly reduced number of total Schwann cells compared with controls, strongly favoring a loss of Schwann cell by apoptosis. In HNPP, the number of total Schwann cells was increased and a significant Schwann cell apoptosis was observed in only 2 patients. Examination of plastic sections and teased nerve preparations from these cases suggested that the Schwann cell apoptosis might be related to the regenerative state of the nerve resulting from the process of sprout pruning. No strict correlation between p75NTR expression and apoptosis was found. These studies indicate that factors regulating Schwann cell number in early postnatal development continue to be important for Schwann cell survival throughout life.

Adult↗
PubMed1997

Late onset muscular dystrophy with cerebral white matter changes due to partial merosin deficiency.

Merosin-deficient congenital muscular dystrophy (CMD) is an autosomal recessive condition usually with onset at birth or within the first months of life. Affected children are severely disabled and usually do not achieve the ability to walk without support. They invariably have white matter abnormalities on brain magnetic resonance imaging (MRI). We report a 29-year-old man with a late childhood onset limb-girdle type muscular dystrophy and cerebral white matter changes on MRI. Immunocyto-chemical studies of the patient's muscle biopsy showed a reduction in expression of the laminin alpha 2 chain of merosin. The patient had three affected siblings, and microsatellite genotyping confirmed linkage to the laminin alpha 2 locus (LAMA2) on chromosome 6q2 in this family. This case probably represents a milder allelic variant of classical merosin-deficient CMD. Merosin status should be assessed in patients with late-onset limb girdle muscular dystrophy.

Adult↗
PubMed1997

Clinical application of Tc-99m tetrofosmin scintigraphy in patients with cold thyroid nodules. Comparison with color Doppler sonography.

We prospectively studied 26 patients with cold thyroid nodules (five malignant and 21 benign nodules) on Tc-99m pertechnetate scintigraphy to investigate the diagnostic value of Tc-99m tetrofosmin scintigraphy and color-Doppler sonography in differentiating malignant from benign thyroid nodules. In each patient, Tc-99m Tetrofosmin uptake in the nodule and intranodule vascularity were assessed semiquantatively. Both the uptake and vascularity were classified as low, Iso or high. Eight out of 26 nodules showed high Tc-99m tetrofosmin uptake; five of them were malignant. Eight (including four malignant tumors) out of 26 nodules showed increased vascularity compared with normal thyroid tissue on color-Doppler sonography. In six out of eight patients with high uptake of Tc99m-tetrofosmin, increased vascularity was observed. The sensitivity, specificity, negative predictive value, and positive predictive value of Tc-99m tetrofosmin scintigraphy and color-Doppler sonography were determined to be 100% and 80%, 85% and 80%, 62% and 50%, and 100% and 94%, respectively. We conclude that color-Doppler sonography seems to have limited value in the detection of malignant thyroid nodules. However, Tc-99m tetrofosmin scintigraphy is a sensitive method to use in diagnosing malignant nodules, although it is not specific for the detection of malignant nodules.

Adenocarcinoma, Follicular↗
PubMed1996

Accumulation of 99Tcm-polyclonal immunoglobulin in different stages of infection: an experimental study.

In this experimental study, the utility of 99Tc(m)-polyclonal human immunoglobulin (99Tcm-HIG) for localizing acute and chronic phases of inflammatory lesions was investigated. Three groups of rats were inoculated with Staphylococcus aureus in the right thigh. Then, 24 h (group I, n = 12), 48 h (group II, n = 12) and 72 h (group III, n = 12) post-inoculation, the rats received 40 MBq 99Tcm-HIG into the jugular vein. In addition, two control rats were studied at 24 h after inoculation of sterile saline. Both visual and quantitative evaluations were undertaken. The acute and chronic stages of inflammation were determined by pathological examination. The mean ( +/- S.D.) lesion/contralateral uptake ratios at 4 and 24 h after 99Tcm-HIG injection were: group I, 1.22 +/- 0.1 and 2.12 +/- 0.16; group II, 1.15 +/- 0.08 and 2.25 +/- 0.16; group III, 1.06 +/- 0.09 and 2.08 +/- 0.14. In conclusion, the acute and chronic phases of infection showed non-significant differences in 99Tcm-HIG uptake ratios.

Abscess↗
PubMed1996

Is 201Tl a reliable agent in tumour imaging?

Thallium-201 (201Tl) imaging has been widely used to differentiate post-therapy reactions from residual viable tumour or local recurrence. However, the ability of 201Tl to discriminate between tumour and post-therapy changes with superimposed infection/inflammation is unclear. This experimental study investigated the localization of 201Tl in infected/inflamed tissues. Twenty-four rats infected with Staphylococcus aureus and 10 rats injected with a standard volume of saline solution (SS) into the thigh muscles were studied. Twenty-four ours after microorganism or SS administration, 18 MBq 201Tl was injected intravenously. Images were recorded at 20 min and 3 h post-injection. The increased tracer uptake was evaluated qualitatively and quantitatively by calculating the ratios (L/C) derived from regions of interest drawn over the lesion and the contralateral thigh muscle. After the imaging procedure, histopathological examination was also performed. Whereas the control group showed no abnormal accumulation of activity, the infected rats demonstrated markedly increased activity, especially on the 20 min images. The mean L/C ratios for the 20 min and 3 h images for the infected rats were 2.18 +/- 0.20 and 1.52 +/- 0.04, respectively (P < 0.0005). In conclusion, positive uptake due to an infective process may limit the use of 201Tl in studies monitoring response to tumour therapy. Although delayed imaging may help to overcome this limitation, further investigations among a large series of patients are required in order to improve the reliability of 201Tl imaging in oncology.

Animals↗
PubMed1995

Seizures with negative phenomena.

Somatic inhibitory seizures and amnesic seizures are thought to occur rarely. We describe a patient with both types of seizures who initially presented with a clinical picture of transient ischemic attack. Neuroradiological investigations revealed a lesion probably a cavernoma located above the parietooccipital sulcus in the isthmus of cingulate gyrus. Anticonvulsant therapy eliminated both types of seizure.

Adult↗
PubMed1995

Alexia without either agraphia or hemianopia in temporal lobe lesion due to herpes simplex encephalitis.

We report a case of alexia without either agraphia or hemianopia following herpes simplex encephalitis. The patient had a temporal lobe lesion with involvement of the occipitotemporal gyrus. This is an unusual cause of alexia without agraphia. The location of the lesion supports the view that transcallosal fibers from the right hemisphere to the left angular gyrus course inferior to the posterior horn of the left lateral ventricle and pass close to the left occipitotemporal gyrus.

Acyclovir↗
PubMed1994

Evaluation of palpable breast masses with 99Tcm-MIBI: a comparative study with mammography and ultrasonography.

We evaluated the feasibility of 99Tcm-methoxyisobutylisonitrile (MIBI) as a tumour localizing agent in patients with palpable breast masses in comparison with mammography and ultrasonography (US). Forty-one patients with palpable masses were studied. An additional 12 women with no palpable breast anomaly also underwent 99Tcm-MIBI breast study. Multiple views were obtained and semiquantitative evaluation was applied. Mammography and US revealed all of the malignant breast masses but differential diagnosis of fibroadenomas could not be achieved. Twenty-five of 27 breast carcinomas were detected using 99Tcm-MIBI scintigraphy. Two patients with invasive lobular carcinoma showed absent MIBI accumulation. Eight of 14 axillary lymph-node metastases showed positive uptake (57%). Twelve of 14 patients with pathologically proven benign breast lesions did not demonstrate any MIBI accumulation. Focal MIBI uptake could be observed in two fibroadenomas. The sensitivity and the specificity of semiquantitative MIBI analysis were 93 and 86%, respectively. Subjective grading offered no additional help in the further differentiation of malignant breast masses. There was no significant difference between histopathological types of breast carcinomas and uptake grades. Our results indicate that 99Tcm-MIBI scintigraphy may provide additional information in the differentiation of malignant pathologies from benign lesions in patients with palpable breast anomalies.

Adult↗
PubMed1993

The value and limitations of 201Tl scintigraphy in the evaluation of lung lesions and post-therapy follow-up of primary lung carcinoma.

In this study 201Tl planar scintigraphy and single photon emission computed tomography (SPECT) were performed in 92 patients with solitary lung lesions in order to distinguish malignant versus benign and metastatic masses and to evaluate the radiotherapy response of 15 primary lung carcinomas. Semiquantitative and quantitative analyses were carried out and the results were compared with histopathological diagnosis. The overall sensitivity, specificity and accuracy of semiquantitative analysis were 56, 71 and 58%, and quantitative evaluations were 88.8, 100 and 92%, respectively. Retention indexes (RI) derived from the early and delayed images were 2.9 +/- 1.3 for primary lung carcinomas, -2.78 +/- 0.9 for benign conditions and -2.3 +/- 1.5 for metastatic pulmonary lesions. 201Tl scintigraphy seems to be a sensitive modality for differentiating malignancies from benign conditions since the difference between those two pathologies is significant. However, this procedure has a limited value in distinguishing metastatic pulmonary lesions from benign pathologies, and in tissue characterization of primary lung carcinomas. On the other hand, a good correlation was observed between 201Tl lung scintigraphy and clinical diagnostic examination during postradiotherapy follow-up of inoperable pulmonary neoplasia.

Adenocarcinoma↗
PubMed1985

Survey on haemoglobin variants, beta thalassaemia, glucose-6-phosphate dehydrogenase deficiency, and haptoglobin types in Turks from western Thrace.

A total of 102 apparently healthy and randomly selected Turks who either immigrated from Western Thrace or were still living there were studied for haemoglobin variants, high Hb A2 beta thalassaemia, G6PD deficiency, and haptoglobin types. The incidence of haemoglobins S and O Arab were 2.9 and 3.9% respectively. The incidence of high A2 beta thalassaemia was 10.8% and that of G6PD deficiency 5%. The gene frequencies of Hp1 and Hp2 were 0.326 and 0.674, respectively.

Adult↗
PubMed1985

Haptoglobin and transferrin types in Eti-Turks.

Haptoglobin and transferrin types were examined in Eti-Turks. The Hp1 frequency was 0.26. With the exception of two individuals with transferrin D, only the transferrin C was observed. The gene frequencies were in the range of most of the Asiatic populations including Turks.

Ethnicity↗