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Biomedical subjects

N Gökçora

Publications and source records attributed to N Gökçora.

At least 19 recordsLinked to original sources
PubMed2003

Abnormality of the left ventricular sympathetic nervous function assessed by I-123 metaiodobenzylguanidine imaging in pediatric patients with neurocardiogenic syncope.

The purpose of this study was to assess the left ventricular sympathetic nervous system function in the patients with neurocardiogenic syncope (NCS) using I-123 metaiodobenzylguanidine (MIBG) imaging of the heart, and to compare the plasma noradrenaline (NA) and MIBG results of tilt positive and tilt negative patients following a head-up tilt test (HUT). The study included 30 patients. Their physical and laboratory examinations did not show a pathology that may be the cause of their syncope. HUT test was positive in 13 patients and negative in 17 patients. Plasma NA concentrations were higher in the HUT positive than the HUT negative group at the beginning and at the 10th minute of the test. Specific I-123 MIBG uptake assessed as the cardiac to mediastinal activity ratio in the delayed image was significantly higher in HUT positive group. The higher levels of MIBG uptake and plasma NA observed in HUT positive patients may reflect the greater capacity of NA storage in cardiac adrenergic neuronal tissue in patients with NCS. The results of this study support the critical role of autonomic nervous system in the pathophysiology of NCS and the excessive sympathetic nervous stimulation as the trigger of paradox reflex.

3-Iodobenzylguanidine↗
PubMed2001

Increased accumulation of Tl-201 in monostotic Paget's disease of the patella: evaluation with quantitative analysis.

Monostotic Paget's disease of the patella was detected with Tc-99m MDP and Tl-201 scans. Diffuse intense uptake of MDP in the left patella was observed on the blood-pool and late phases of the bone scan. Tl-201 imaging was performed to differentiate a malignant process and showed diffuse marked accumulation at the same site. Semiquantitative analysis of the patella region on both Tc-99m MDP and Tl-201 scans did not support a diagnosis of cancer. Radiographs showed the features of Paget's disease of the bone. Findings of a pathologic evaluation were compatible with the diagnosis of osteitis deformans. This case represents the unusual skeletal involvement of monostotic Paget's disease of the bone in the patella. Tl-201 accumulation in the Paget's lesion was suggested to be caused by increased metabolic activity of the lesion but was not indicative of a malignant process.

Aged↗
PubMed1999

Tc-99m HMPAO brain perfusion imaging in young Down's syndrome patients.

Down's syndrome (DS) is characterized by moderate mental retardation and a variety of abnormalities involving multiple organ systems. There is a high incidence of Alzheimer's disease (AD) type dementia beyond the age of 35. In this study, single photon emission computed tomography (SPECT) brain perfusion imaging of young Down's syndrome patients was performed to define the perfusion pattern. Tc-99m HMPAO brain perfusion SPECT was performed on 17 young DS patients, aged 3-24 years (mean: 10.9+/-5.9 years). None of the patients had dementia symptoms. Brain perfusion scans were acquired 15 min after i.v. injection of 12 MBq/kg of Tc-99m HMPAO using a single head rotating gamma camera. Images were analyzed visually and semiquantitatively by defining side-to-side asymmetry index. Nine DS cases showed normal brain perfusion. Eight of the 17 cases revealed mostly unilateral parieto-temporal, parieto-occipital and frontal hypoperfusions. The side-to-side asymmetry indices for these visually interpreted regional brain perfusion abnormalities ranged from 6 to 15%. These findings revealing mostly unilateral parieto-temporal and frontal hypoperfusions may not be considered as predictive patterns of dementia related Alzheimer type perfusion deficits in DS. However, such findings may connect to other functional imaging studies related to the higher cortical dysfunction in mental retardation.

Adolescent↗
PubMed1998

Stress hyperglycemia in minimally invasive surgery.

This study examined the selected hormonal responses to, and hormone-mediated glucose metabolism during minimally invasive surgery in, patients undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Thirty-two patients with symptomatic gallstone disease were included in this study and scheduled for open or laparoscopic procedure in a randomized trial. Results are expressed as mean and standard error of the mean. Statistical evaluations were performed with Mann-Whitney U and Wilcoxon signed-rank tests. Blood cortisol, glucagon, insulin, and glucose concentrations were measured immediately in the preoperative period and 6 h after surgery. Blood cortisol, glucagon, and glucose concentrations increased significantly after open and minimally invasive surgery, while insulin levels and the insulin:glucagon ratio remained unchanged. The rise of glucagon and cortisol values was found to be significantly higher in the postoperative period of the open procedure, than in the laparoscopic approach. However, in the patients who underwent open surgery, the increase in glucose concentrations was not significantly higher in the postoperative period. Surgery-induced hormonal effects on the islets increase glucagon and suppress insulin secretion. The glucagon-mediated increase in hepatic glucose production is excluded by the posttraumatic insulin levels from the insulin-sensitive tissues. A bihormonal setting favors a greater rate of hepatic glucose production in both open and laparoscopic surgery. Hormonal changes do reflect the degree of surgical stress, but their metabolic consequences are not parallel to the grade of surgical trauma in minimally invasive surgery.

Cholecystectomy, Laparoscopic↗
PubMed1997

Comparison of indium-111 octreotide and thallium-201 scintigraphy in patients mammographically suspected of having breast cancer: preliminary results.

Indium-111 octreotide and thallium-201 scintigraphic studies were compared in 21 patients (16 with palpable and five with non-palpable lesions) suspected of having breast malignancies on the basis of mammography. Early (15 min) and late (3 h) 201Tl (111 MBq) and 4-h and 24-h 111In-octreotide (111-148 MBq) static planar anterior images (matrix 256 x 256) were obtained on separate days. Images were evaluated both visually and quantitatively. Biopsy was performed following the imaging studies. Histopathology revealed 17 breast carcinomas (15 cases of invasive ductal carcinoma, one mucinous adenocarcinoma and one intraductal carcinoma) and four benign breast lesions (two fibroadenomas, one abscess and one case of fat necrosis). The means histopathological tumour size (mean largest diameter) was 3.38 +/- 1.9 cm. 111In-octreotide detected 16 of the 17 breast cancers (94%) while 201Tl detected 13 of them (76%). Both 111In-octreotide and 201Tl missed one non-palpable carcinoma showing only an isolated cluster of microcalcifications on mammography. The smallest tumour size detected by both agents 1.5 x 1.5 cm. Of the four benign lesions, only the breast abscess revealed both 201Tl and 111In-octreotide uptake. 111In-octreotide scan also showed tracer uptake in five of the six patients with histologically proven axillary metastases, while four of these six patients showed 201Tl uptake. The tumour/background (T/B) ratios of late 111In-octreotide and 201Tl images were 1.71 +/- 0.38 and 1.46 +/- 0.30 respectively (P = 0.039). In this preliminary study, 111In-octreotide yielded more favourable results than 201Tl in the detection of breast carcinomas. However, the diagnostic efficacy of 111In-octreotide imaging needs to be investigated in larger patient series.

Breast Diseases↗
PubMed1997

Tl-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study.

PURPOSE: To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy. MATERIALS AND METHODS: Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other. RESULTS: Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases. CONCLUSIONS: In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

Adult↗
PubMed1997

Comparison of sputum and serum eosinophil cationic protein (ECP) levels in nonatopic asthma and chronic obstructive pulmonary disease.

The aim of the present study was to investigate whether sputum eosinophil cationic protein (ECP) concentrations could be a useful marker in the differential diagnosis between intrinsic asthma and chronic obstructive pulmonary disease (COPD). For this purpose total blood eosinophil counts were obtained and concentrations of serum and sputum ECP from 10 nonatopic asthmatics with a mild attack and 9 COPD patients with acute exacerbation were measured by radioimmunoassay. Mean serum ECP concentration was 54.3 +/- 23.0 micrograms/L in the asthmatic group and 83.3 +/- 79.2 micrograms/L in the COPD group (p: n.s.). In the group of asthmatics mean sputum ECP level was 984.5 +/- 1245.5 micrograms/L/g sputum and in the COPD group it was 417.5 +/- 363.5 micrograms/L/g sputum. There was no significant difference in sputum ECP levels between patients with asthma and COPD. We conclude that neither sputum nor serum ECP levels are useful markers in differential diagnosis of asthma attack and acute exacerbation of COPD.

Adult↗
PubMed1997

201Tl scintigraphy in the evaluation of palpable and nonpalpable breast lesions: correlation with mammography and ultrasonography.

AIM: Our goal was to determine the clinical usefulness of Tl-201 to identify breast cancer in patients with suspicious breast lesions on clinical examination, and/or abnormal radiologic (mammography and/or ultrasonography) findings. METHODS: Tl-201 scintigraphy were performed in sixty-eight patients with 70 breast abnormalities (51 palpable, 19 nonpalpable) and compared with mammography and ultrasonography (US). Early (15 min) and late (3 h) images of the breasts were obtained following the injection of 111 MBq (3 mCi) of Tl-201. Visual and semiquantitative interpretation was performed. RESULTS: Final diagnosis confirmed 52 malignant breast lesions and 18 benign conditions. Tl-201 visualized 47 of 52 (90%) overall malignant lesions. Thirty-eight of 40 (95%) palpable and 9 of 12 (75%) nonpalpable breast cancers were detected by Tl-201 scintigraphy. The smallest mass lesion detected by Tl-201 measured 1.5 x 1.0 cm. Eleven breast lesions were interpreted as indeterminate by mammography and/or sonography. Tl-201 scintigraphy excluded malignancy in 7 of 8 (88%) patients with benign breast lesions interpreted as indeterminate. Five of the 18 (28%) benign breast lesions showed Tl-201 uptake. None of the fibroadenoma and fibrocystic changes accumulated Tl-201. Tl-201 scintigraphy, mammography and ultrasonography showed 90%, 92%, 85% overall sensitivity and 72%, 56%, 61% overall specificity respectively. Twenty-one of the 28 (75%) axillary nodal metastatic sites were also detected by Tl-201. In malignant and benign lesions, early and late lesion/contralateral normal side (L/N) ratios were 1.58 +/- 0.38 (mean +/- SD) and 1.48 +/- 0.32 (p > 0.05), 1.87 +/- 0.65 and 1.34 +/- 0.20 (p < 0.05) respectively. The mean early and late L/N ratios of malignant and benign groups did not show statistical difference (p > 0.05). CONCLUSION: Overall, Tl-201 scintigraphy was the most specific of the three methods and yielded favourable results in palpable breast cancers, while it showed lower sensitivity in nonpalpable cancers and axillary metastases. Combined use of Tl-201 scintigraphy with mammography and US seems to be useful in difficult cases, such as dense breasts and indeterminate breast lesions.

Adult↗
PubMed1996

Effects of EGF and allopurinol on prostaglandin and lipid peroxide levels in mucosa of stomach in restraint cold stress.

The cold and restraint gastric stress models were used in rats. Mucosal levels of prostaglandins, which have a protective effect on cells, and lipid peroxidation, a possible etiological factor in stress-induced gastric mucosal injuries, were investigated. Epidermal growth factor (EGF), which protects the gastric tissue from stress-induced lesions, and allopurinol, which inhibits xanthine oxidase, were given intraperitoneally. Both EGF and allopurinol decreased lipid peroxidation at the mucosal surface of the stomach. At the same time, allopurinol increased the serum gastrin levels and decreased the mucosal prostaglandin levels. It is concluded that EGF protects the gastric mucosal surface by way of increased tissue prostaglandin levels. EGF also decreased both serum gastrin and tissue malondialdehyde, an indicator of lipid peroxidation.

Allopurinol↗
PubMed1996

The changes in serum type I and III procollagen, insulin-like growth factor-I and insulin-like growth factor binding protein-3 levels in children with chronic renal failure.

Serum levels of carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) can be used as markers of bone formation and the evaluation of children with growth disorders. We measured the serum levels of these collagens by radioimmunoassay (RIA), insulin-like growth factor I (IGF-I) (by immunoradiometric assay) and insulin-like growth factor binding protein-3 (IGFBP-3) (by RIA) levels in 24 children aged between 4 and 14 years with chronic renal failure (CRF) (n = 12 dialysis, n = 12 non-dialysis) and 12 age-matched healthy controls, to find out whether these parameters have a prognostic or therapeutic value on monitoring of growth retardation in CRF. Mean serum IGFBP-3 and PIIINP levels in the dialysis patients were higher than the control group, the difference between the groups was statistically significant (P < 0.05). It seemed that the pubertal stage of the patients did not affect the levels of PICP, PIIINP, and IGFBP-3 while serum IGF-I levels in pubertal patients were significantly higher than those in prepubertal patients (P < 0.001). There was no significant correlation between PICP and PIIINP in any patients. Neither PICP nor PIIINP correlated with height z-score, bone age, IGF-I, or IGFBP-3. It was concluded that the increased serum IGFBP-3 and PIIINP levels in chronic renal disease are poor prognostic indicators leading to progressive renal failure and end-stage renal disease (ESRD). Further investigations into the effects of these collagens on growth failure associated with CRF are needed.

Adolescent↗
PubMed1996

Effects of inhaled steroid treatment on serum eosinophilic cationic protein (ECP) and low affinity receptor for IgE (Fc epsilon RII/sCD23) in childhood bronchial asthma.

Serum eosinophilic cationic protein (ECP) and soluble low affinity receptor for IgE (Fc epsilon RII/sCD23) concentrations were measured in relation to symptom-medication scores, pulmonary function, and total IgE levels in 27 chronic allergic asthmatic children (17 boys, 10 girls), mean age 10.8 years, before and at the end of a three month inhaled corticosteroid (budesonide) treatment period. Serum ECP and sCD23 concentrations were also measured in age matched non-asthmatic controls with allergic rhinitis. All asthma patients had significantly higher serum ECP and sCD23 than the controls, whereas the mean serum IgE was not different. No correlation between total IgE concentrations and serum sCD23 could be detected in either group. At the end of the treatment period, symptom-medication scores and pulmonary function improved. Serum ECP and sCD23 concentrations were reduced; however, total IgE values did not change significantly. A significant relation was found between the improvement of symptom-medication scores and fall in both sCD23 and ECP concentrations. Although there was a significant correlation of pulmonary function values with serum ECP, no such relation was observed for sCD23. It appears that serum sCD23 and ECP concentrations could be good disease markers, particularly in asthma. Monitoring of serum inflammation markers, especially ECP, may be useful in the follow up of asthmatic children on anti-inflammatory treatment.

Adolescent↗
PubMed1996

Changes in serum type I and III procollagen levels in children with chronic renal failure.

Serum levels of carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) can be used as markers of bone formation and the evaluation of children with growth disorders. We measured the serum levels of these collagens with radioimmunoassay in 24 children aged between 4 and 14 years with chronic renal failure (CRF; n = 12 dialysis, n = 12 nondialysis) and 12 age-matched healthy controls, to find out whether these parameters have a prognostic or therapeutic value in monitoring the growth retardation in CRF. Mean serum PIIINP levels in the dialysis patients were higher than in the control group; the difference between the groups was statistically significant (p < 0.05). It seemed that the pubertal stage of the patients did not affect the levels of PICP and PIIINP. There was no significant correlation between PICP and PIIINP in any patients. Neither PICP nor PIIINP correlated with the height z-score or bone age. It was concluded that the increased serum PIIINP levels in renal patients might be accepted as a poor prognostic factor leading to progressive renal failure and end-stage renal disease. Further investigations into the effects of these collagens on growth failure associated with CRF are needed.

Adolescent↗
PubMed1995

Tumor necrosis factor-alpha (TNF-alpha) in pleural fluids.

Our study was undertaken to investigate the role of tumor necrosis factor-alpha (TNF-alpha) at the site of disease activity in tuberculous pleuritis (TP). Concentrations of TNF-alpha were measured directly by radioimmunoassay (RIA) in the pleural fluid (PF) and plasma (P) of patients with TP (n = 14), malignant effusions (n = 18) and transudates (n = 7). Among these three groups mean plasma levels of TNF-alpha were not statistically significant (P > 0.05), but in the TP group mean levels of TNF-alpha in PF were significantly higher than in the cancer and transudate groups (P < 0.001), and there was no significant difference between the cancer and transudate groups (P > 0.05). These results may indicate a local synthesis of TNF-alpha by cells within the pleural cavity in this disease.

Adolescent↗
PubMed1995

Changes in serum levels of IGF-I and IGFBP-3 in children with chronic renal failure.

The significance of serum insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3) levels in uremia is still controversial. In this study we measured serum IGF-I by immunoradiometric assay (IRMA) and IGFBP-3 levels by specific radioimmunoassay (RIA) in 28 children (aged 3-16 years) with end-stage (n = 14, on hemodialysis) and pre-terminal renal failure (n = 14) and in 15 age-matched healthy children. Thyroid function of the patients was also investigated and GH-stimulation tests with L-Dopa and insulin were performed. Neither IGF-I nor IGFBP-3 levels significantly correlated with mean height SDS for bone age or for chronological age in either non dialysis patients or pubertal (n = 10) or prepubertal patients (n = 18). These data was consistent with the concept that growth in CRF was not related to abnormalities in serum IGF-I or IGFBP-3 levels.

Adolescent↗
PubMed1994

Treatment of autonomous thyroid nodules: safety and efficacy of sonographically guided percutaneous injection of ethanol.

OBJECTIVE: We evaluated the efficacy of sonographically guided percutaneous injection of ethanol as an alternative to surgery and administration of radioiodine, which have a higher risk of complications, for treatment of autonomously functioning thyroid nodules that may develop hyperthyroidism. SUBJECTS AND METHODS: Sixteen patients between 23 and 67 years of age who had solitary autonomous thyroid nodules were included in the study. The nodules were detected and evaluated using physical examination, measurements of hormonal levels, sonography, and scintigraphy. Sonographically guided percutaneous injection of ethanol was repeated one to two times each week for a total of four to eight treatments. The amount of ethanol used was 0.5-9.0 ml per treatment, depending on the volume of the nodule. RESULTS: Patients were followed up for at least 18 months. Clinical evaluation, including laboratory tests, showed that the patients' signs and symptoms subsided and hormones returned to normal levels in all cases. Scintigrams showed that the normal thyroid tissue that was suppressed before treatment regained normal function. Sonograms showed that the volume of the nodules decreased in 13 of 16 cases. No early or late permanent complications associated with treatment were noted. CONCLUSION: Our results show that sonographically guided percutaneous injection of ethanol can be used as an alternative treatment of autonomous thyroid nodules with the aim of eliminating the possible risk factors of surgery and radioiodine. This method of treatment may be particularly desirable in patients who are poor candidates for surgery and who refuse standard treatment.

Ethanol↗
PubMed1993

Regional cerebral blood flow in Angelman syndrome.

A patient with typical features of Angelman syndrome--a genetically inherited disorder involving developmental delay, ataxia, episodes of paroxysmal laughter and brachiocephaly--was studied with single-photon emission tomography. Hypoperfusion found in the left frontal and left temporoparietal regions can provide insights into the functional cerebral pathology, which may be due to a disturbance of the developmental process related to a chromosomal abnormality.

Angelman Syndrome↗
PubMedDate not supplied

Serum levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in children with insulin-dependent diabetes mellitus.

Pubertal development has recently been evaluated from the standpoint of changes in insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) levels in healthy children. We studied puberty related changes in serum IGF-I and IGFBP-3 levels in 24 patients (11 prepubertal) with insulin dependent diabetes mellitus (IDDM) and 26 healthy subjects (14 prepubertal). Serum IGF-I and IGFBP-3 levels were assayed using immunoradiometric assays and radioimmunoassays, respectively. Serum IGF-I and IGFBP-3 levels in diabetics did not increase during puberty, as opposed to those in healthy children. Serum IGF-I and IGFBP-3 levels of diabetic patients were found to be lower than those of control subjects during puberty (p < 0.0001 and p < 0.05, respectively). Proteolysis is believed to be a general mechanism to increase IGF bioavailability in the presence of IGFBPs. Increased IGFBP-3 protease activity has been shown in sera of children with IDDM as well as a decrease in this activity in response to insulin therapy. Our data displaying low IGFBP-3 levels in diabetic children may be due to increased proteolysis, which also causes a shift in IGF-I to its lower molecular weight forms. Higher rate of clearance of the latter may be the reason for the low IGF-I levels we observed in children with IDDM. The moderate correlation between insulin dose and IGFBP-3 levels (r = 0.5, p < 0.01) may suggest insulin to be a contributing factor in the regulation of IGFBP-3 levels. We conclude that regulation of IGF-I and IGFBP-3 concentrations is disturbed in children with IDDM, in particular during adolescence.

Adolescent↗