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Biomedical subjects

A Celik

Publications and source records attributed to A Celik.

At least 37 records · Page 2Linked to original sources
PubMed2001

Laparoscopic management of a giant adrenal cyst: case report.

A 22-cm left adrenal cyst in a 30-year-old woman was laparoscopically drained and then excised. The main symptom was dull left-upper-quadrant pain. Operative time was 95 minutes, and the hospital stay was 1 day. The patient returned to normal activity 7 days after surgery. Histology revealed a benign adrenal cyst. At the 3-month follow-up, ultrasonography showed the absence of any cystic recurrence, and adrenal endocrine function was normal. The advantages and disadvantages of this modality for the management of adrenal gland cysts are discussed.

Adrenal Gland Diseases↗
PubMed2001

Acute renal failure following latrodectism.

Latrodectism is considered dangerous for human beings. Acute renal failure after envenomation is not common and usually results from prerenal failure. We report a 59-y-o man with acute oliguric renal failure due to a combination of prerenal and renal causes after being bitten by a black Latrodectus spider. He had the characteristic anxiety, severe hypertension, tremor, facial edema, and generalized diaphoresis. The patient recovered within a week without sequelae. Clinicians should not overlook the possibility of acute renal failure in latrodectism.

Acute Kidney Injury↗
PubMed2000

Catalytic oxidation of p-cresol by ascorbate peroxidase.

Transient and steady state kinetics, together with a range of chromatographic and spectroscopic techniques, have been used to establish the mechanism and the products of the H(2)O(2)-dependent oxidation of p-cresol by ascorbate peroxidase (APX). HPLC, GC-MS, and NMR analyses are consistent with the formation of 2, 2'-dihydroxy-5,5'-dimethylbiphenyl (II) and 4alpha,9beta-dihydro-8, 9beta-dimethyl-3(4H)-dibenzofuranone (Pummerer's ketone, III) as the major products of the reaction. In the presence of cumene hydroperoxide, two additional products were observed which, from GC and MS analyses, were shown to be 1,1-dimethylbenzylalcohol (IV) and bis-(1-methyl-1-phenyl-ethyl)-peroxide (V). The product ratio II:III was dependent on enzyme concentration: at low concentrations Pummerer's ketone (III) predominates and at high concentrations formation of the biphenyl compound (II) is favored. Steady-state data showed a sigmoidal dependence on [p-cresol] that was consistent with the presence of 2.01 +/- 0.15 binding sites for the substrate (25.0 degrees C, sodium phosphate, pH 7.0, mu = 2.2 mM) and independent of ionic strength in the range 2.2-500 mM. Single turnover kinetic experiments (pH 7.0, 5.0 degrees C, mu = 0.10 M) yielded second-order rate constants for Compound I reduction by p-cresol, k(2), of 5.42 +/- 0.10 x 10(5) M(-1) s(-1), respectively. Rate-limiting reduction of Compound II by p-cresol, k(3), showed saturation kinetics, giving values for K(d) = 1.54 +/- 0.12 x 10(-3) M and k(3) = 18.5 +/- 0.7 s(-1). The results are discussed in the more general context of APX-catalyzed aromatic oxidations.

Ascorbate Peroxidases↗
PubMed2000

Serum immunoglobulins and immunoglobulin G subclasses with recurrent wheezing.

In this study serum immunoglobulins (Ig) and IgG subclasses were measured in 42 patients (ranging 9 month-6 year) with recurrent wheezing and in 37 healthy children determined the relationship between serum Igs and recurrent wheezing. Patients were divided into two groups according to the age [9 month-2 year (n: 15), and 2-6 year (n: 27)]. In the patients placed in 9-24 month age group, serum IgG4 level was found to be lower than controls (p < 0.05). But there was not a significant difference in mean serum concentrations of total IgG, IgA, IgM, IgE, IgG1, IgG2 and IgG3 subclasses between the groups (P > 0.05). In the 25 month-6 year age group the mean IgE level was increased compared to the control while IgG3 and IgG4 levels were decreased (p < 0.05). On the other hand, in the 9-24 month age group there was no significant difference between the patients and controls for IgG subclasses deficiency (P > 0.05). However, significant difference in IgG subclasses deficiency was present between the patients and controls in the 25 month-6 year group (P < 0.001). In conclusion, our findings suggest that wheezing in childhood may be associated with low IgG3 and/or IgG4, and in older children high IgE level may be a part of pathogenetic mechanism in patients with recurrent wheezing.

Child↗
PubMed2000

Results of rhabdomyosarcoma treatment in a developing country.

Fifty-one children (median age: 4.5 years; 4 months-16 years) diagnosed with rhabdomyosarcoma were treated in our center between 1980-1999. The primary sites were head and neck in 31.4%, the genito-urinary system in 21.6%, and extremities in 9.8% of the patients. The histopathologic subtypes were embryonal in 80.4%, alveolar in 9.8%, and undifferentiated in 9.8%. The majority of the patients were considered group III (47%) and group IV (25.5%) according the criteria of the Intergroup Rhabdomyosarcoma Study (IRS). Primary total tumour resection was performed in only 27.5% of the patients. The patients were treated with assigned regimens of IRS II and IRS III protocols. Radiotherapy was applied to 92.1% of the patients. Thirty-four patients (66.7%) were lost to follow up, and of the remaining 17 patients, 7 patients (41.2%) died, relapse occurred in 9 patients (52.9%) and 10 patients (58.8%) are alive. The percentage of cases lost to follow up during the first 10 years and the following 9 years of the study were 77.4% and 50%, respectively. In compliance with cancer treatment remains a major problem in developing countries.

Adolescent↗
PubMed2000

[Gastritis localization and GERD incidence in patients with Cag A(+) and Cag A(-) Helicobacter pylori infection].

The relationship between Helicobacter pylori (HP) and gastroesophageal reflux disease (GERD) is very complex and still not well understood. However, many issues, even those as basic as whether HP induces or protects against GERD, are still controversial. The gastritis location could play also a role in the induction of GERD. Some investigators suggested that infection by the Cag A strain of HP seems to have a positive association with reflux esophagitis. Therefore, the aim of this study was to investigate the relationship between GERD, gastritis location, HP infection and Cag A positivity.

Adolescent↗
PubMed1999

Regional cerebral blood volume: a comparison of the dynamic imaging and the steady state methods.

Accurate assessment of regional cerebral blood volume (rCBV) is of critical importance in the study of cerebrovascular disease and other disorders of the central nervous system. Currently, magnetic resonance imaging (MRI) is able to measure rCBV non-invasively with two commonly used methods: the dynamic imaging (DI) and steady state (SS) approaches. In this study, two questions were investigated. First, how do partial volume effects between gray matter (GM) and white matter (WM) and between epicortical vessels and brain parenchyma affect the estimation of rCBV when using the SS approach? Second, how comparable are the ratios of rCBV in GM to rCBV in WM (rCBV GM/WM) obtained with the two methods? We used a paramagnetic contrast agent, OPTIMARK (Mallinckrodt, St. Louis, MO), at a dose of 0.2 mmol/kg in anesthetized pigs (n = 6) to obtain rCBV maps using both methods. When a 10% rCBV threshold was used to minimize effects from large epicortical vessels, and tissue segmentation was used to separate GM from WM, rCBV values of 4.8 +/- 0.3% and 3.3 +/- 0.5% were obtained for GM and WM, respectively, with the SS approach. Significantly higher rCBV values for both GM (P < 0.001) and WM (P < 0.01) were observed when the contribution from large epicortical vessels was not removed. When tissue segmentation and rCBV thresholding were used on SS data, an rCBV GM/WM ratio of 1.5 +/- 0.2 was obtained. This value did not differ significantly from the rCBV GM/WM ratio of 1.8 +/- 0.6 obtained using the DI approach.

Animals↗
PubMed1999

Primary torsion of the omentum in a 6-year-old boy: report of a case.

In the absence of any pathological condition in the pelvis of children who present with acute abdomen, the observation of serosanguineous intraabdominal fluid should prompt the surgeon to investigate the omentum. A 6-year-old boy who was admitted with a clinical picture of acute appendicitis, and was later diagnosed during a laparotomy to have primary torsion of the omentum, is reported. Obesity, exercise, and the presence of a bifid omentum were confirmed to be the predisposing factors.

Child↗
PubMed1999

Safer circumcision in patients with haemophilia: the use of fibrin glue for local haemostasis.

OBJECTIVE: To evaluate the efficacy and the reduced costs of factor concentrates in circumcision by using fibrin glue in patients with haemophilia. PATIENTS AND METHODS: Eleven patients with haemophilia (age range 6-14 years, 10 with haemophilia A, one with haemophilia B) were circumcised using fibrin glue for local haemostasis and to reduce the duration of clotting factor replacement after surgery. Circumcision was carried out under general anaesthesia; the prepuce was incised circumferentially and excised using the Gomco clamp technique. Haemophiliac patients were divided into two groups: in group 1 (four patients, three with haemophilia A and one with haemophilia B) the factor levels were assessed every 8 h and bolus injections of factor repeated during the first 4 days after surgery; in group 2, the seven remaining haemophilia A patients received a postoperative bolus injection and approximately 4 U/kg per hour of factor substitution for the first 2 days after surgery by continuous infusion. Eleven other patients with haemophilia A underwent circumcision using same surgical procedure but were given only factor substitution without fibrin glue, and served as a control group (group 3). RESULTS: None of the patients had significant bleeding or complications. The total costs were significantly reduced, to $8898 per patient in group 1 and $4866 per patient in group 2, when compared with $12875 per patient in group 3 (both P<0.05). CONCLUSION: Fibrin glue is a useful treatment for circumcision in patients with haemophilia; it lessens the need for factor substitution after circumcision and thus reduces the high cost of treatment.

Adolescent↗
PubMed1999

Quantitative magnetic resonance imaging in experimental hypercapnia: improvement in the relation between changes in brain R2 and the oxygen saturation of venous blood after correction for changes in cerebral blood volume.

Acute hypercapnia simultaneously induces increases in regional cerebral blood volume (rCBV) and the oxygen saturation of cerebral venous blood (Yv). Changes in both physiologic parameters may influence the changes in R2 (deltaR2) that can be measured in the brain with gradient echo magnetic resonance imaging. The authors examined the effect of incorporating independent measurements of the change in rCBV (deltarCBV) on the fidelity of the relation between deltaR2 and deltaYv in the setting of experimental hypercapnia. A two-dimensional T2-weighted gradient echo sequence was used to measure deltaR2 in the brain parenchyma of anesthetized rats in response to hypercapnia with respect to the control state. In parallel, estimates of rCBV were obtained using a three-dimensional steady-state approach in conjunction with a paramagnetic contrast agent during both control and hypercapnic states so that a deltarCBV could be calculated. Regional CBV values of 2.96 +/- 0.82% and 5.74 +/- 1.21% were obtained during the control and hypercapnic states, respectively, and linear relations between rCBV and CO2 tension in both arterial (r = 0.80) and jugular venous (r = 0.76) blood samples were obtained. When correlating deltaR2 directly with deltaYv, no clear relation was apparent, but a strong linear relation (r = 0.76) was observed when correction for deltarCBV was incorporated into the data analysis. These results are consistent with the current understanding of the mechanisms of blood oxygen level-dependent (BOLD) contrast and underscore the potential importance of taking into account deltarCBV when quantitative estimates of deltaYv from the "BOLD effect" are intended.

Animals↗
PubMed1999

Increased-contrast, high-spatial-resolution, diffusion-weighted, spin-echo, echo-planar imaging.

An insertable head gradient coil with a maximum gradient amplitude of 45 mT/m and a rise time of 150 musec along all three major axes was used to collect high-spatial-resolution, single-shot, spin-echo, echo-planar, diffusion-weighted magnetic resonance images with b values ranging from 0 to 2,200 sec/mm2. Improvements in spatial resolution allowed better visualization of large white matter tracts and their relation to adjacent anatomic structures. Excellent contrast and anatomic detail were revealed for most structures in the brain when a sufficient number of acquisitions were collected.

Adult↗
PubMed1998

Experimental hypoxemic hypoxia: changes in R2* of brain parenchyma accurately reflect the combined effects of changes in arterial and cerebral venous oxygen saturation.

A two-dimensional T2*-weighted gradient-echo sequence was used to image the rat brain before and during graded hypoxemia. Changes in R2* (deltaR2*) with respect to the control state were calculated for brain parenchyma and were compared with changes in hemoglobin saturation measured from both arterial and jugular venous blood samples. DeltaR2* was first correlated with the changes in arterial (deltaYa) and venous (deltaYv) hemoglobin saturations individually. Although a general trend toward a linear relationship with deltaR2* was observed for both deltaYa and deltaYv, neither alone was strong (correlation coefficients r=0.71 and 0.75 for deltaYa and deltaYv, respectively, and standard errors of the regression (SER)=0.52 and 0.48 for deltaYa and deltaYv, respectively). However, when an "effective" cerebral blood hemoglobin saturation change (deltaYb) was constructed that takes into account the approximate weighting of the contributions from the arterial and venous phases of the circulation (deltaYb = 0.75 x deltaYv + 0.25 x deltaYa), a stronger correlation with deltaR2* was obtained and there was less variance (r=0.87 and SER=0.35). It is concluded that an appropriate weighting of the contributions of arterial and venous phases of the circulation must be taken into account in modeling the volume susceptibility effects of deoxyhemoglobin on R2* of brain parenchyma. In this way, a more accurate relationship between deltaR2* and deltaYb can be obtained.

Analysis of Variance↗
PubMed1998

Effects of acute normovolemic hemodilution on T2*-weighted images of rat brain.

Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-2.2% to 33.4+/-2.1%) and moderate (Hct reduced from 44.6+/-2.7% to 26.2+/-1.7%). A two-dimensional gradient-echo sequence was used to monitor signal changes with high temporal resolution before, during, and after HD protocols. The time course of signal intensity change was closely related to that of changes in Hct. Corresponding changes in R2* (deltaR2*) with respect to the pre-HD state were calculated for the brain parenchyma. Average deltaR2* values of -0.24+/-0.06 s(-1) and -0.40+/-0.07 s(-1) were obtained for the mild and moderate HD groups, respectively, during the final 2 min of MR imaging (proximal to correlative measurements of Hct). MR measured deltaR2* values were in close agreement with the expected changes in R2* predicted from theory when the measured changes in Hct were used as independent variables. These data are in good agreement with the current understanding of the effects of changes in the intravascular concentration of deoxyhemoglobin on induced magnetic susceptibility and hold promise for quantitative measurement of brain oxygenation in vivo.

Analysis of Variance↗