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Biomedical subjects

A Yildiz

Publications and source records attributed to A Yildiz.

At least 55 records · Page 3Linked to original sources
PubMed2001

The volume effect of the stomach on intestinal activity on same-day exercise--rest Tc-99m tetrofosmin myocardial imaging.

PURPOSE: The aim of this study was to investigate quantitatively the volume effect of the stomach on the prevention of intestinal artifacts in the rest phase on same-day exercise--rest Tc-99m tetrofosmin myocardial perfusion scintigraphy. MATERIALS AND METHODS: The study was performed in 81 consecutive patients (43 men, 38 women; mean age, 57 +/- 9 years) who were referred for routine Tc-99m tetrofosmin exercise--rest SPECT myocardial perfusion imaging with normal scintigrams or completely normal inferior wall perfusion on visual assessment of SPECT images. Group A (control group, n = 41) and group B (n = 40) were given 200 ml milk to enhance the hepatobiliary clearance of tetrofosmin 30 minutes before the exercise SPECT acquisition study and just after the injection for the rest SPECT acquisition study. For the rest SPECT acquisition study, patients in group B were given, in addition to milk, a standard solid and fluid meal to enhance the volume of the stomach after the injection of Tc-99m tetrofosmin. In all patients, both exercise and rest SPECT acquisitions were started 45 minutes after the injection of Tc-99m tetrofosmin. Myocardial and abdominal activity were assessed on three separate views in the rest phase of the study, and the mean myocardium-to-abdomen count ratios were calculated. In addition, the presence of interfering intestinal activity was assessed visually on SPECT images. Infracardiac activity was described as absent when it was equal to lung background. RESULTS: The myocardial-to-abdominal ratios were 1.38 +/- 0.05 and 1.95 +/- 0.04 in groups A and B, respectively (P < 0.0001). Interfering intestinal activity with varying degrees of intensity was seen in 20 patients in group A (49%) and in 5 patients in group B (13%; P < 0.001). CONCLUSIONS: These results suggest that filling of the stomach with some fluid and solid food before rest acquisition on the same-day stress--rest protocol, because of its volume effect, may provide a high target-to-nontarget ratio for myocardial imaging and thus may reduce the frequency of intestinal artifacts.

Artifacts↗
PubMed2001

Gamma probe-guided resection and scanning with TC-99m MIBI of a local recurrence of follicular thyroid carcinoma.

A 30-year-old woman underwent two operations for multinodular goiter and follicular thyroid carcinoma. The residual thyroid tissue was ablated by I-131 therapy. After 7 years of follow-up, Tc-99m MIBI and I-131 scintigraphy were performed, because her serum thyroglobulin level was much higher compared with the control analysis performed in the sixth year. Tc-99m MIBI showed pathologic accumulation, which could be consistent with a local recurrence, whereas the results of I-131 scintigraphy were negative. The locally recurring follicular thyroid carcinoma was resected using a gamma probe and Tc-99m MIBI. The thyroglobulin level decreased to a normal level after surgery. This case shows that the intraoperative use of a gamma probe with Tc-99m MIBI allows localization of recurrent thyroid tissue in the scarred area in patients with increased radionuclide accumulation, and scanning of the affected area using the gamma probe may be helpful in determining whether resection is complete.

Adenocarcinoma, Follicular↗
PubMed2001

The evaluation of sacroiliitis using 99mTc-nanocolloid and 99mTc-MDP scintigraphy.

The role of imaging studies in the evaluation of patients with sacroiliitis is controversial. We aimed to evaluate the role of nanocolloid and bone scintigraphy in patients with sacroiliitis and to investigate the clinical relevance of imaging findings. Thirty-two patients with clinically sacroiliac disease (nine females, 23 males, aged 22-47 years) underwent scintigraphic and radiographic examinations and all imaging studies were performed within 2 weeks. Twenty-five subjects were also included as a control group (10 females, 15 males, aged 20-51 years) for quantitative analysis of the bone scan. The quantitative analysis was done by using regions of interest drawn over the right and left sacroiliac (SI) joint and sacrum (S) and SI/S ratios were calculated. Abnormal uptake was defined as an uptake higher than the mean +/- 2 SD of the control SI/S values. Bone scintigraphy was performed using a three-phase technique and single photon emission computed tomography (SPECT). Nanocolloid scintigraphy (NS) was performed 1 h later, after administration of 370 MBq 99mTc-nanocolloid, and evaluated visually. Each of the scintigraphic examinations was performed on separate days within the same week. Sensitivity values were 25%, 47%, 69% and 97%, and specificity values were 80%, 90%, 95% and 90% in quantitative bone scanning (QBS), 99mTc-NS, planar and SPECT bone imaging, respectively, when the clinical findings were considered as the 'gold standard'. Our results showed that bone SPECT scanning was more sensitive than planar imaging, but planar imaging was the most specific method. SPECT was also the most associated technique with clinical findings. 99mTc-NS was neither specific nor sensitive enough in the detection of sacroiliitis although it could be helpful for the confirmation of inflammation.

Adult↗
PubMed2001

The outcome of patients presenting with crush syndrome after the Marmara earthquake.

In this study, we evaluated the clinical and laboratory data of the patients presenting after the Marmara earthquake. Crush syndrome was diagnosed in 60 patients (30 M, 30 F, mean age: 31.3+/-13.8 years). They were buried under the rubble for a mean period of 12.3+/-15.1 hours. On admission, 27 patients were oligoanuric and the mean serum creatinine, creatinine phosphokinase and potassium levels were 4.4+/-3.2 mg/dl, 18453.1+/-24527.2 IU/L, and 4.9+/-1.7 mEq/L, respectively. The most frequent site of trauma was the lower extremity. Dialysis treatment was initiated in 40 patients (19 M, 21 F; mean age: 32.7+/-13.0 years). Mean number of hemodialysis sessions/patient was 8.9+/-6.8. Nine (23%) patients among the dialyzed and 4 (20%) among the non-dialyzed died leading to an overall mortality of 21.6%. This low mortality rate suggests that the death rate from acute renal failure due to crush syndrome could be decreased by extensive follow-up.

Acute Kidney Injury↗
PubMed2000

Immunization of renal transplant recipients with pneumococcal polysaccharide vaccine.

BACKGROUND: Streptococcus pneumoniae, a common pathogen leading to pneumonia, is a cause of morbidity and mortality in immunosuppressed patients. Vaccination against this agent can be recommended for immunosuppressed patients, including those with chronic renal failure, nephrotic syndrome and renal transplant recipients; however, a diminished immune response and loss of protective antibodies have been observed. PATIENTS AND METHODS: In our prospective study, the efficacy and side effects of polyvalent pneumococcal vaccination were investigated in renal transplant recipients. A total of 21 patients (6 female, 15 male) with well-functioning renal allografts, who had transplant surgery at least 2 months before, were included in the study. The patients were stratified according to the immunosuppressive protocol and 8 received double, while 13 received triple, immunosuppressive agents. After obtaining basal serum samples, all cases were vaccinated with the 0.5 mL intramuscular administration of polyvalent polysaccharide pneumococcal vaccine (Pneumo 23 Pasteur Merieux, lot No: K 1131). RESULTS: Following a mean of 6 wk in all patients and also a mean of 12 wk in 12 patients, serum samples were again obtained to measure pneumococcal antibodies. Antibody titers following 6 and 12 wk of vaccination were significantly higher, as compared with basal values in all patients, except one. These titers did not show any statistically significant difference between double and triple therapies. There was no significant difference between the 12th and 6th wk postvaccination antibody titers. No systemic or local adverse effects were observed. CONCLUSION: Pneumococcal vaccination is safe and effective in patients with well-functioning renal allografts, at least in the short term. This vaccination policy may be useful for preventing invasive pneumococcal disease in immunosuppressed patients.

Adult↗
PubMed2000

Effects of alendronate and hormone replacement therapy, alone or in combination, on bone mass in postmenopausal women with osteoporosis: a prospective, randomized study.

The effectiveness of hormone replacement therapy (HRT) and alendronate, alone and in combination, was evaluated in 120 postmenopausal patients with osteoporosis with bone mineral density (BMD) measurements at least 2 SD below the mean value for young premenopausal subjects. They had no contra-indications to HRT or alendronate use and were randomized to three different treatment groups. Group I was treated with micronized 17 beta-oestradiol 2 mg and norethisterone acetate 1 mg/day per os, group II received alendronate 10 mg/day per os and group III received micronized 17 beta-oestradiol 2 mg, norethisterone acetate 1 mg/day per os and alendronate 10 mg/day per os for 1 year. Elementary calcium 1500 mg/day was supplied to patients in all three groups. Spinal and femoral neck BMD and markers of bone mineral metabolism were measured on each patient before treatment and 6 and 12 months after treatment in 95 patients. At the end of the 12th month, significant increases in spinal and femoral neck BMD were found in all groups. Increases in spinal BMD were significantly higher in patients treated with alendronate and alendronate with HRT when compared with patients treated with HRT only. No significant difference was found in femoral neck BMD changes between the groups. Significant decreases in bone resorption and markers of bone formation were observed in all groups. Alendronate was found to be more effective than HRT and could have a very beneficial effect when added to the HRT regimen in patients with postmenopausal osteoporosis. Alendronate might also be used in postmenopausal patients with osteoporosis when HRT is contra-indicated or when there is reluctance to use hormonal treatment.

Alendronate↗
PubMed2000

Correlation of thallium-201 uptake with proliferating cell nuclear antigen in brain tumours.

The aim of this study was to assess the correlation between thallium-201 (201Tl) uptake and proliferative activity measured using the proliferating cell nuclear antigen labelling index (PCNA-LI) in brain tumours. Twenty-nine patients with brain tumours were included in this study. Of these, seven were diagnosed with meningioma, 13 had high grade glioma (HGG) and nine had low grade glioma (LGG). A 210Tl single photon emission computed tomography study was performed on all patients before operation, and 201Tl uptake index (UI) and retention index (RI) values were calculated. Cell proliferation was determined by PCNA. While all of the HGGs and meningiomas showed intense 201Tl accumulation on visual interpretation, eight of the nine LGGs did not show accumulation of 210Tl at the tumour site. 201Tl UI values were 3.23+/-0.89 and 2.67+/-0.66 in HGG, 1.27+/-0.18 and 1.23+/-0.09 in LGG, and 4.35+/-1.60 and 2.52+/-0.78 in meningioma on early and delay images, respectively. There was a statistical difference between the 201Tl UI in HGG and LGG. PCNA-LI values were 16.72+/-6.15%, 1.63+/-0.81% and 2.00+/-1.88% in HGG, LGG and meningioma, respectively. The PCNA-LI in HGG was significantly higher than in LGG and meningioma. While the correlation coefficient between the 201Tl UI and the PCNA-LI was 0.94 in gliomas (n=22), there was no correlation in meningiomas. No statistically significant correlation was found between the RI and the PCNA-LI in gliomas. The presence of a strong positive correlation between 201Tl uptake and PCNA-LI indicates that 201Tl uptake can predict the proliferative activity of the glioma.

Adult↗
PubMed2000

Regional cerebral blood flow in schizophrenia before and after neuroleptic medication.

In order to investigate cerebral perfusion changes induced by neuroleptic drugs, we performed 99Tc(m) hexamethyl propyleneamine oxime (HMPAO) single-photon emission computed tomography (SPET). Fifteen patients (nine drug naive, six non-naive) diagnosed by using the DSM-III-R criteria, and 10 right-handed age and sex matched normal volunteers were included in this study. The SPET study was performed with 740 MBq 99Tc(m)-HMPAO by using a 128 x 128 matrix, 30 s/frame for a total 64 view over 360 degrees before and after 1 month of neuroleptic treatment. A semiquantitative method was used for the analysis. Patients were clinically assessed using the Brief Psychiatric Rating Scale (BPRS). There was no significant regional cerebral blood flow (rCBF) difference between the patient group and control group in whole-brain regions except in the left temporal lobe. Although clinical scores of the patients improved after neuroleptic treatment no statistically significant difference was found in the rCBF between pre- and post-treatment. Moreover, there was no statistically significant correlation between the rCBF and BPRS in any region. These results suggest that there was a discrepancy between the clinical situation and rCBF in schizophrenia and the lateralized temporal lobe blood flow, which may have important implications for the evaluation of patients with schizophrenia.

Adult↗
PubMed2000

No association between deletion-type angiotensin-converting enzyme gene polymorphism and left-ventricular hypertrophy in hemodialysis patients.

Left-ventricular hypertrophy (LVH), a bad prognostic sign, is a common finding in hemodialysis patients. The aim of the study was to analyze factors, including angiotensin-converting enzyme (ACE) genotype that may have an effect on the development of LVH in hemodialysis patients. Seventy-nine hemodialysis patients (42 males, 37 females, mean age 37.7 +/- 13.1 years) and 82 age- and sex-matched normotensive healthy controls (40 males, 42 females, mean age 35.6 +/- 5.7 years) were included. Left-ventricular mass index (LVMI) was higher in the hemodialysis group compared to controls (170.1 +/- 69.3 versus 84.9 +/- 15.7 g/m(2), p < 0.001). Fourty-three hypertensive patients in the hemodialysis group had an increased LVMI compared to 36 normotensive hemodialysis patients (194.2 +/- 75.5 versus 141.2 +/- 48.0 g/m(2), p < 0.001). On univariate analysis, LVMI was found to be correlated with blood pressure (r = 0.38, p < 0.001), time spent on dialysis (r = 0.22, p = 0.02) and hemoglobin levels (r = -0.21, p = 0.03). No correlation was found between LVMI and age (r = 0.09, p = 0.22), predialytic creatinine (r = 0.09, p = 0.21) and albumin (r = -0.10, p = 0.18). On multivariate analysis for the predictors of LVMI, blood pressure, time spent on dialysis and hemoglobin levels were also found to be significant. LVMI in DD, ID and II genotypes were 155.0 +/- 71.2, 181.6 +/- 60.6, and 163.6 +/- 83.4 g/m(2), respectively (p > 0.05). No association between LVMI and DD genotype was found. ACE genotype distribution was similar in hemodialysis patients and healthy controls. It was concluded that LVH in hemodialysis patients was mainly related to hypertension, anemia and time spent on dialysis and the DD genotype had no effect on LVMI in hemodialysis patients.

Adult↗
PubMed2000

Comparison of different treatment modalities for postmenopausal patients with osteopenia: hormone replacement therapy, calcitonin and clodronate.

OBJECTIVE: To evaluate the effectiveness of hormone replacement therapy (HRT), clodronate, calcitonin and a clodronate plus calcitonin combination in postmenopausal patients with osteopenia. METHODS: One hundred postmenopausal patients with osteopenia, with bone mineral density (BMD) measurements at least one standard deviation below the mean value for young premenopausal subjects (T score < -1), were studied. They had no contraindications to HRT, clodronate or calcitonin use and were randomized to four different treatment groups. Patients in group I were treated with transdermal estradiol 50 micrograms/day and oral medroxyprogesterone acetate 10 mg/day during the last 12 days of the month; group II received oral clodronate 400 mg/day for 1 month out of every 3 months; group III received calcitonin nasal spray 100 IU/day; and patients in group IV were treated with oral clodronate 400 mg/day for 1 month out of every 3 months plus calcitonin nasal spray 100 IU/day. Elementary calcium 1000 mg/day was supplemented to patients in all groups. Spinal and femoral neck BMD measurements and markers of bone mineral metabolism were measured in each patient before treatment and 6, 12 and 18 months after treatment in 86 patients. RESULTS: Significant increases in mean lumbar spine BMD were found in the group receiving HRT, and at the end of 18 months there was a 2.69 +/- 0.76% increase, compared with baseline. Mean femoral neck BMD also increased by 2.22 +/- 0.57% in the HRT group; this was significantly different from baseline, resulting in a higher bone mass gain than in the other three groups. Increases in both lumbar spine and femoral neck BMD were found in patients treated with clodronate, although the only significant increase was observed in lumbar spine BMD at the end of 18 months. The mean changes in BMD were not significantly different, compared with the other groups, and at the end of 18 months there was a 2.20 +/- 0.58% increase at the lumbar spine. The mean vertebral and femoral neck BMD did not change significantly throughout the study period in patients receiving calcitonin. At the end of 18 months, there was a 0.13 +/- 0.52% decrease and a 0.11 +/- 0.49% increase in mean lumbar spine and femoral neck BMD, respectively, compared with baseline. The combination of clodronate plus calcitonin increased mean lumbar spine and femoral neck BMD by 2.08 +/- 1.05% and 1.46 +/- 1.09%, respectively, at the end of 18 months, but these increases were not significantly different from those in the groups where these agents were used alone. Significant decreases in bone resorption and in markers of bone formation were observed in all groups. CONCLUSION: HRT was found to be the most effective treatment regimen in postmenopausal patients with osteopenia, compared with clodronate, calcitonin and a clodronate plus calcitonin combination. Clodronate or calcitonin might be alternatives when HRT is contraindicated or refused by the patient; although calcitonin was found to be less effective. The clodronate plus calcitonin combination was not superior to either of these agents when used alone.

Adult↗
PubMed1999

Tuberculosis in renal transplant recipients.

BACKGROUND: Tuberculosis is an important cause of morbidity and mortality in renal transplant recipients, but there are insufficient data regarding the efficacy and complications of therapy and of INH prophylaxis. METHODS: This study is a retrospective review of the records of 880 renal transplant recipients in two centers in Turkey. RESULTS: Tuberculosis developed in 36 patients (4.1%) at posttransplant 3-111 months, of which 28 were successfully treated. Eight patients (22.2%) died of tuberculosis or complications of anti-tuberculosis therapy. Use of rifampin necessitated a mean of 2-fold increase in the cyclosporine dose, but no allograft rejection occurred due to inadequate cyclosporine levels. Hepatotoxicity developed in eight patients during treatment, two of whom died due to hepatic failure. No risk factor, including age, gender, renal dysfunction, hepatitis C, or past hepatitis B infection, was found to be associated with development of hepatic toxicity. A subgroup of 36 patients with a past history of or radiographic findings suggesting inactive tuberculosis, was considered to be at high risk for developing active disease, of whom 23 were given isoniazid (INH) prophylaxis. None versus 1 of 13 (7.7%) of cases with and without INH prophylaxis, respectively, developed active disease (P>0.05). None of the patients receiving INH had hepatic toxicity or needed modification of cyclosporine dose. CONCLUSIONS: These data show that tuberculosis has a high prevalence in transplant recipients, that it can effectively be treated using rifampin-containing antituberculosis drugs with a close follow-up of serum cyclosporine levels, and that INH prophylaxis is safe but more experience is needed to define the target population.

Adult↗
PubMed1999

No relation of tuberculin reactivity with quantitative analysis of peripheral blood lymphocyte subsets in haemodialysis patients.

Anergic response to tuberculin (PPD) is well known in haemodialysis patients (HDp). This cross-sectional controlled study was conducted to analyse the correlation of PPD response with demographical features, nutritional parameters and the distribution of peripheral blood lymphocyte (PBL) subtypes. In this study 29 HDp (17 men, 12 women; mean age 30.9 +/- 9.5 years) and 13 controls (eight men, five women; mean age 29.2 +/- 6.4 years) were included. The mean time spent on dialysis was 20.5 +/- 17.4 months. The mean PPD response was lower in HDp than controls (7.5 +/- 8 mm vs. 15 +/- 4 mm, P = 0.001). Fourteen patients (48%) were PPD (-) (eight men, six women; mean age 34.1 +/- 11.1 years) and 15 were PPD (+) (normergic) (nine men, six women; mean age 26.8 +/- 3.4 years). No difference was observed between PPD (-) and (+) groups for age, sex and time spent on dialysis. As nutritional parameters, body mass index, serum albumin, creatinine and cholesterol levels were measured and no differences were found between controls and the PPD (-) and (+) groups. Absolute lymphocyte counts were lower in HDP compared to controls (1290 +/- 296 vs. 1570 +/- 307 cells ml-1; P = 0.01). PBL subtype percentages and absolute counts (CD3, CD4, CD8, CD4/CD8, HLADR+CD3+, CD16+56+, CD19) were also similar between PPD(-) and (+) HDp. It was concluded that PPD response cannot be predicted by the distribution of PBL subtypes. The most probable cause of this observation is regulation of PPD reactivity by in situ immune cells whose composition is not reflected in the distribution of PBL.

Cross-Sectional Studies↗
PubMed1999

The prognostic importance of severity and type of post-transplant proteinuria.

Proteinuria, developing after renal transplantation may influence allograft and patient outcomes. This study aimed to investigate the effect of proteinuria on patient and allograft survival. Among 514 patients, 56 (11%) patients with good allograft function and proteinuria were evaluated retrospectively. Patients with proteinuria were classified as group P (20 patients with permanent proteinuria, Male/Female: 16/4) and group T (36 patients with temporary proteinuria, M/F: 29/7) according to the type of proteinuria. Also, considering the amount of proteinuria, patients were classified as group M (32 patients with massive proteinuria, M/F: 29/3) and group NM (24 patients with non-massive proteinuria, M/F: 16/8). The mean time interval between transplantation and appearance of proteinuria was 23.7 months (range 0-121 months) and no difference was found between groups. Two- and 5-yr allograft survival rates were found to be 85 and 80% in group M, and 95 and 82% in group NM. respectively (p = 0.24). In terms of type of proteinuria, 2- and 5-yr allograft survival rates were found to be 70 and 58% in group P and 92 and 87% in group T, respectively. The difference between groups P and T was found to be statistically significant (p = 0.02). Most (85%) of the patients with permanent proteinuria also had massive proteinuria. In conclusion, we found a significant relation between type and severity of proteinuria. The type of post-transplant proteinuria had a stronger effect on allograft outcome than the severity of proteinuria.

Adult↗
PubMed1999

Helicobacter pylori antibodies in hemodialysis patients and renal transplant recipients.

In this cross-sectional, controlled study, Helicobacter pylori (H. pylori) infection, a probable factor in the development of gastrointestinal problems, was investigated in dialysis patients and renal transplant recipients. Forty-seven dialysis patients (22 male, 25 female, mean age of 36.6 +/- 15 yr (range 18-83 yr)), 57 renal transplant recipients (39 male, 18 female, mean age of 36.8 +/- 10 yr (range 19-60 yr)) and 55 healthy individuals (34 male, 21 female, mean age of 33.4 +/- 9.6 yr (range 21-58 yr)) were included and no significant difference was found in the study groups. The mean time spent on dialysis in the hemodialysis group was 32.5 +/- 27.7 months (range 1-100 months). H. pylori antibodies were detected in 22 of 57 (38.6%) patients in the transplantation group, 31 of 47 (65.9%) patients in the dialysis group and 39 of 55 (72.5%) in the control group. No correlation was found between H. pylori infection and age, sex, primary disease, frequency of dialysis, duration and type of transplantation and the immunosuppressive therapy. However, patients with H. pylori antibodies spent a shorter time on dialysis compared to patients without the antibodies (26.6 +/- 23.5 vs 44.1 +/- 32.1 months, p = 0.038). The frequency of H. pylori infection in the transplantation group was significantly lower than the control and dialysis groups (p < 0.01). This finding may be explained on the basis of decreased humoral antibody response to H. pylori infection, secondary to immunosuppressive therapy rather than decreased incidence of infection in the transplantation group. Finally, we concluded that the value of the serological test for diagnosis of H. pylori infection should be interpreted cautiously in these patient groups.

Adolescent↗
PubMed1999

Immune response to Haemophilus influenzae type B vaccination in renal transplant recipients with well-functioning allografts.

BACKGROUND: Haemophilus influenzae infection is a mild and self-limited disease in the healthy population. However, it may show an aggressive course in the immunocompromised state which underlines the importance of vaccination against this agent. On the other hand, posttranplant immunosuppression may impair immune responses and thus the efficacy of the vaccination. METHODS: Forty-three renal transplant recipients with well-functioning allografts were immunized with H. influenzae type b vaccine in order to investigate the immune response. The patients received a double or a triple immunosuppressive protocol. Seven healthy members of the dialysis unit served as controls. After obtaining basal serum samples, the patients and the control subjects were immunized with H. influenzae type b conjugate vaccine. After 6 and 12 weeks, serum samples obtained again to determine H. influenzae type b antibody titers. RESULTS: The antibody titers 6 and 12 weeks after vaccination were significantly higher as compared with the basal values, similar to those of the control subjects. These titers did not show statistically significant differences between the double and triple immunosuppressive therapy groups. After 12 weeks of vaccination, the antibody titers did not show a statistically significant difference as compared with those obtained after 6 weeks. CONCLUSION: H. influenzae type b vaccination is safe and effective in patients with well-functioning renal allografts and should be recommended to renal transplant recipients who may have the risk of invasive disease on the basis of the immunosuppressive state.

Adolescent↗