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Biomedical subjects

S Ozdemir

Publications and source records attributed to S Ozdemir.

At least 19 recordsLinked to original sources
PubMed2003

Vegetable oils used as vitamin E vehicle affect the electrical activity of the rat heart.

The aim of this study is to define the possible effects of vegetable oils used as vitamin E vehicle on the electrical activity of the rat heart. To test the possible effects of vitamin E vehicles we studied the effect of i.p. injected corn oil, hazelnut oil or peanut oil on the action potential parameters recorded in both papillary and left atrial muscle strips. Four experimental groups were used. The control group was injected (i.p.) with distilled water, while the three remaining groups received injections of corn oil, hazelnut oil, or peanut oil for five weeks (in a dose of 0.4 ml/kg/day--minimum amount of oil in which vitamin E could be dissolved). We used borosilicated (15-20 megaohms) capillary electrodes and intracellular action potentials (AP) were recorded in isolated papillary and left atrium muscle strips. While administration of three different types of vegetable oil had no significant effect on AP parameters of papillary muscle, they significantly prolonged the repolarization phase of AP in atrial strips. These results show that vegetable oils used as vitamin E vehicles may alter the electrical activity of the heart in a tissue-dependent manner. The present data indicate that the possible effect of vegetable oil vehicles should be kept in mind while evaluating the possible effects of in vivo vitamin E administration.

Action Potentials↗
PubMed2002

Comparison of long-term quality of life after laparoscopic and open cholecystectomy.

BACKGROUND: Although many studies have compared open and laparoscopic procedures, showing many advantages in favor of the laparoscopic technique during the early postoperative period, only a limited number of reports in the literature compare the two techniques during the later follow-up period with regard to quality of life. This study aimed to compare the effects of these two cholecystectomy techniques on the quality of life and clinical outcome of the patients during long-term follow-up evaluation. METHODS: This study evaluated 200 patients who underwent cholecystectomy operations with either technique between 1993 and 1999 in our department. There were 100 patients in each group. Both groups were similar with respect to age, gender, body mass indexes, American Society of Anesthesiology (ASA) scores, and indications for surgery. The Medical Outcome Study Short Form 36 Health survey (SF-36), which includes 36 items, was used for evaluating the quality-of-life index. In addition to this, a system-specific instrument for gastrointestinal diseases was used to investigate clinical outcome. RESULTS: The mean administration time for the questionnaire was 46.8 +/- 18.7 months in the laparoscopic cholecystectomy (LC) group and 41.5 +/- 16 months in the open cholecystectomy (OC) group. Statistically significant differences were noted in the scores for all eight SF = 36 health status domains in favor of laparospopic surgery. No statistically significant difference was found for abdominal pain, location of the pain, referral to a doctor for the pain, accompanying symptoms, relieving factors for the pain, distention, and dyspeptic complaints, usage of antacid therapy, weight changes, changes in bowel habit, need for a special diet, or sexual functions between the two groups. CONCLUSIONS: The gastrointestinal clinical symptoms were similar in the two groups during the long-term follow-up evaluation, but laparoscopic cholecystectomy was found to be significantly superior to the open technique with respect to the quality of life over the long term.

Abdominal Pain↗
PubMed2002

Laparoscopic renal biopsy in bilateral pelvic kidney with chronic glomerulonephritis.

Percutaneous needle biopsy under the guidance of ultrasound or computerized tomography is the most valuable method in the diagnosis of parenchymal kidney diseases. However, sometimes it can be difficult to perform in the presence of certain anomalies, anatomic variations, or medical problems. In the presence of bilateral pelvic kidney, which is a rare anomaly, laparoscopy can be used to obtain biopsy. Biopsy of kidney was planned in a 26-year-old woman who presented with a history of hypertension for 7 years and proteinuria with the diagnosis of nephrotic syndrome. For the biopsy, the laparoscopic approach was chosen since the patient had bilateral pelvic kidneys. Under general anesthesia, using three port sites, the right kidney was reached, which was located more anterior than the left one. Three biopsy specimens for histologic evaluation were taken with a Tru-Cut biopsy needle. No complications were encountered during or after the operation. The patient was ceased from urological follow-up after performing an ultrasound on the first postoperative day. This is the first case of pelvic kidney with chronic glomerulonephritis reported in the literature in which the histologic diagnosis was made with the help of laparoscopy. Laparoscopic kidney biopsy is a minimally invasive technique that can be done in cases with anatomic variations, making percutaneous needle biopsy impossible.

Adult↗
PubMed2002

Mapping the mesoscale interface structure in polycrystalline materials.

A new experimental approach to the quantitative characterization of polycrystalline microstructure by scanning electron microscopy is described. Combining automated electron backscattering diffraction with conventional scanning contrast imaging and with calibrated serial sectioning, the new method (mesoscale interface mapping system) recovers precision estimates of the 3D idealized aggregate function G(x). This function embodies a description of lattice phase and orientation (limiting resolution approximately 1 degree) at each point x (limiting spatial resolution approximately 100 nm), and, therefore, contains a complete mesoscale description of the interfacial network. The principal challenges of the method, achieving precise spatial registry between adjacent images and adequate distortion correction, are described. A description algorithm for control of the various components of the system is also provided.

Journal Article↗
PubMed2002

Effects of excessive copper intake on hematological and hemorheological parameters.

Copper plays an important role in the structure and function of metalloproteins and in the absorption of iron. The present study deals with the effects of excessive copper intake on hematological and hemorheological parameters. Drinking water containing 250 microg/mL copper for a period of 9 wk, Wistar albino rats showed increased erythrocyte count, blood viscosity, and hematocrit values (p<0.05) and lower hemoglobin (p<0.05) than controls fed a normal diet. The two groups also had differences in the erythrocyte deformability index. The results suggest that excessive copper intake results in hematological and hemorheological changes affecting both the protein content of the erythrocyte membrane and heme synthesis.

Animals↗
PubMed2002

Plasmapheresis: an effective therapy for refractory hyperthyroidism in the elderly.

Hyperthyroidism in the elderly often presents diagnostic challenges. Elderly patients rarely present with classical signs and symptoms of hyperthyroidism. More commonly, their presentation is ayical which leads to a delay in making a diagnosis. Such delays can sometimes decrease the functional capacity of the affected patient and reduce their chance for recovery. Herein we report a 66-year-old woman whose diagnosis of hyperthyroidism was delayed. Standard therapies were ineffective. Plasmapheresis was performed to control the manifestations of the hyperthyroid state, resulting in improvement in the patient's condition.

Aged↗
PubMed2001

Orthotopic liver transplantation for Wilson's disease: a single-center experience.

BACKGROUND: Wilson's disease is an inherited disorder of copper metabolism characterized by reduced biliary copper excretion, which results in copper accumulation in tissues with liver injury and failure. Orthotopic liver transplantation (OLT) can be lifesaving for patients with Wilson's disease who present with fulminant liver failure and for patients unresponsive to medical therapy. The aim of this study is to review our experience with OLT for patients with Wilson's disease. METHODS: Between 1988 and 2000, 21 OLTs were performed in 17 patients with Wilson's disease. Patient demographics, pre-OLT laboratory data, operative data, and early and late postoperative complications were reviewed retrospectively. One-year patient and graft survival was calculated. RESULTS: Eleven patients had fulminant Wilson's disease; in six patients the presentation was chronic. Mean patient age at presentation was 28 years (range 4-51 years); mean follow-up was 5.27 years (range 0.4-11.4 years). Neurologic features of Wilson's disease were not prominent preoperatively and did not develop post-OLT except in one patient who developed acute neuropsychiatric illness and seizure. Renal failure, present in 45% of patients with fulminant Wilson's disease, resolved post-OLT with supportive care. One-year patient and graft survivals were 87.5% and 62.5%, respectively. Fifteen survivors have remained well with normal liver function and no disease recurrence. CONCLUSION: Liver transplantation for hepatic complications of Wilson's disease cures and corrects the underlying metabolic defect and leads to long-term survival in patients who present with either acute or chronic liver disease. Acute renal failure develops frequently in patients with fulminant Wilsonian hepatitis and typically resolves postoperatively.

Adult↗
PubMed1999

A case of fibrosing mediastinitis with obstruction of superior vena cava and downhill esophageal varices: a rare cause of upper gastrointestinal hemorrhage.

Fibrosing mediastinitis (FM) is an excessive fibrotic reaction that occurs in the mediastinum and may lead to compression of mediastinal structures (especially vascular or bronchial). In the present study we describe the first case report of FM, in a patient who developed downhill esophageal varices and bleeding, which was secondary to superior vena cava obstruction.

Administration, Oral↗
PubMed1998

Antineutrophil cytoplasmic antibodies in childhood systemic lupus erythematosus.

We aimed to evaluate the presence of peripheral antineutrophil cytoplasmic antibodies (p-ANCA) and cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA) in children with SLE and to correlate its association of laboratory findings. Twenty-one children with SLE were studied. Serum samples in patients were tested by indirect immunofluorescence (IIF) slide kit (INOVA) for c-ANCA and p-ANCA and by ELISA for myeloperoxidase (MPO-ANCA) and proteinase 3 (PR3-ANCA). All the patients but two were quiescent for lupus at the time of sampling. Sixteen of 21 patients showed positive IIF staining whereas only 5 had MPO-ANCA and 2 of nine PR3-ANCA. The data suggests that SLE may be associated p-ANCA directed against additional target antigens rather than MPO and may be implicated in the pathogenesis of SLE or may be only non-specific antibodies developed in lupus.

Adolescent↗
PubMed1998

A rare complication of renal biopsy in a child with membranoproliferative glomerulonephritis.

Percutaneous renal biopsy is essential for the definitive diagnosis of chronic glomerulonephritis. Large arteriovenous fistula (AVF) which is a rare complication of native renal biopsy is generally diagnosed in the first weeks after the procedure. We present a childhood membranoproliferative glomerulonephritis case with an enormous AVF presenting with severe hypertension 15 months after the biopsy that was successfully embolized. In conclusion, AVF must be considered in children having chronic glomerulonephritides even if hypertension appears late after the renal biopsy.

Aneurysm, False↗
PubMed1998

The flow of excitation energy in LHCII monomers: implications for the structural model of the major plant antenna.

Spectral and kinetic information on energy transfer within the light-harvesting complex II (LHCII) monomer was obtained from this subpicosecond transient absorption study, by using selective excitation (663, 669, 672, 678, and 682 nm) of various Chl a absorption bands and detecting the induced changes over the entire Qy region (650-700 nm). It is shown that transfer from the pigment(s) absorbing around 663 nm to the low energy ones occurs in 5 +/- 1 ps, whereas the 670-nm excitation is delivered to the same "destination" in two phases (0.30 +/- 0.05 ps, and 12 +/- 2 ps), and a fast equilibration (lifetime 0.45 +/- 0.05 ps) takes place within the main absorption band (675-680 nm). From comparison with results from similar time-resolved measurements on trimeric samples, it can be concluded that the intramonomeric energy transfer completely determines the spectral equilibration observed in native LHCII complexes. To correlate the measured lifetimes and their associated spectra with the pigment organization within the available structural model of LHCII (. Nature. 367:614-621), extensive but straightforward theoretical modeling was used. Thus it is demonstrated that the pigment assignment (Chl a or Chl b) given by Kuhlbrandt and co-workers cannot simultaneously describe the dichroic spectra and the transient absorption results for the rather homologous LHCII and CP29 proteins. A more recent assignment for CP29, in which a Chl b molecule ("Chl b5") is identified as a Chl a (Dr. R. Bassi, personal communication), leads to a much better description of both CP29 and LHCII. Furthermore, the orientations of the transition dipole moments, which have not been obtained in the crystal structure, are now assigned for most of the Chl's.

Biophysical Phenomena↗
PubMed1998

Nutritional assessment of children on haemodialysis: value of IGF-I, TNF-alpha and IL-1beta.

BACKGROUND: Protein-energy malnutrition (PEM) is associated with increased morbidity and mortality in haemodialysis (HD) patients. Insulin-like growth factor I (IGF-I) has proved to be a sensitive marker of malnutrition, while interleukin-1 (IL-1beta) and tumour necrosis factor (TNF) have been found to be raised in catabolic states. METHODS: We have investigated the nutritional status of 17 chronic renal failure (CRF) paediatric patients (8 boys, 9 girls) on maintenance HD. Eight predialysis CRF children (5 boys and 3 girls; mean creatinine 5.1+/-3.2 mg/dl) and 10 healthy children served as control groups. PEM was defined according to anthropometric measurements (triceps skinfold thickness (TST), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC)). These were correlated with serum IGF-I, IL-1, TNF-alpha, transferrin, and albumin (all sampled before the HD session). RESULTS: In the HD group, TST was reduced in 41.2% of the patients, whereas MAC and MAMC were reduced in 82.4 and 76.5% respectively. TST was depleted in only one of the predialysis CRF children. The degree of reduction in MAC and MAMC were 62.5 and 62.5% respectively. Median serum IGF-I level was decreased in both HD and predialysis CRF patients (205.1 interquartile range (IQR) 194.4 microg/l and 258.8 IQR 155.0 microg/l respectively) compared to the healthy children (418.0 IQR 310.5 microg/l) (P=0.0009 and P=0.01 respectively). Within the HD group, IGF-I levels were lower in patients with malnutrition defined according to TST (145.0 IQR 125.5 microg/l) compared to children with normal TST (301.2 IQR 218.8 microg/l) (P=0.05). IGF-I levels of the HD patients with malnutrition according to TST was also lower than the predialysis CRF patients and healthy children (P=0.04 and P=0.002 respectively). Serum IL-1beta was undetectable in all groups. Median serum TNF-alpha levels were higher in HD and predialysis CRF patients compared to healthy children, albeit statistically insignificant. There was no correlation between TNF-alpha, transferrin or albumin and anthropometric parameters. CONCLUSIONS: Our results support the high prevalence of malnutrition in CRF children, which becomes more pronounced when treatment by HD is initiated. We suggest that determination of IGF-I levels in childhood HD patients in conjunction with anthropometric measurements is useful for identification of malnutrition. We have not been able to demonstrate the catabolic effects of cytokines on this state of protein energy malnutrition.

Adolescent↗