Biomedical subjects

A Imamoğlu

Publications and source records attributed to A Imamoğlu.

10 recordsLinked to original sources

PubMed2001

Controlling photons using electromagnetically induced transparency.

It is well known that a dielectric medium can be used to manipulate properties of light pulses. However, optical absorption limits the extent of possible control: this is especially important for weak light pulses. Absorption in an opaque medium can be eliminated via quantum mechanical interference, an effect known as electromagnetically induced transparency. Theoretical and experimental work has demonstrated that this phenomenon can be used to slow down light pulses dramatically, or even bring them to a complete halt. Interactions between photons in such an atomic medium can be many orders of magnitude stronger than in conventional optical materials.

Journal Article↗

PubMed2000

Effects of cisapride on ventricular repolarization in children.

Life-threatening ventricular dysrhythmias mainly attributed to QTc prolongation have been reported in adults and children who were using cisapride, a prokinetic agent that facilitates gastrointestinal motility. Recent adult and paediatric case reports have suggested an association of malignant ventricular dysrhythmias with administration of cisapride in conjunction with drugs that inhibit its cytochrome P-450 metabolism. Therefore, to analyse the time- and dose-related effects of cisapride on ventricular repolarization, we prospectively studied infants and children receiving cisapride with no concomitant medications. Standard 12-lead resting ECGs were obtained from 38 patients (mean age: 6.6 +/- 4.4 y) before the first dose of cisapride (0.8-1.2 mg/kg/d) therapy, and 3 d, 7 d and 1 mo after the first dose of continuing cisapride therapy. The corrected QT interval (QTc), dispersion of QT and QTc (QTD, QTcD) were calculated. Patients were divided into two groups according to dose of cisapride: Group 1 (n = 22) (0.8 mg/kg/d), Group 2 (n = 16) (1.2 mg/ kg/d). Data obtained from these patients were compared with a control group consisting of 372 normal children. No clinical adverse effects such as palpitations, presyncope or syncope were noted during the study. Baseline QTc, QTD and QTcD measurements of the study group were not different from those of the control group. Mean QTc values of the study group on days 7 and 30 of cisapride therapy were found to be significantly higher than those of the control group (p < 0.001 and <0.0001, respectively). Mean QTc values of the study group on days 7 and 30 of therapy were also significantly higher than those of baseline value (p < 0.01 and <0.001, respectively). Mean QTD and mean QTcD values that were recorded throughout the cisapride treatment in the study group were not found to be different from the baseline values and the values of the controls. Mean QTD and QTcD were also not found to be different between Groups 1 and 2. However, mean QTc was found to be more significantly increased from baseline at the first month of therapy in Group 2 (p < 0.05). The results of this study suggest that cisapride treatment cause prolongation of ventricular repolarization without causing increased heterogeneity of repolarization (QT dispersion). However, the clinical significance of this effect is unclear, because all the patients in this study group remained asymptomatic, without signs of dysrhythmia.

Action Potentials↗

PubMed1999

Relation of mass/volume ratio to ECG abnormalities and symptoms in children with aortic stenosis/insufficiency.

In this study, to determine whether symptoms and ECG abnormalities relate to left ventricular (LV) mass, volume, and mass/volume (M/V) ratio in children with aortic stenosis (AS) and/or insufficiency (AI), the authors examined 23 patients with echocardiography. LV volumes and mass were calculated with echocardiography. Also, the peak and mean gradients across the aortic valve and left ventricular meridional wall stress (ESWS) were determined by use of echo Doppler techniques. Fourteen patients (mean age 5.84+/-3.49 years) had AS alone. Of these, 14 had symptoms and seven had abnormal-appearing ECGs. Nine patients (mean age 6.91+/-4.35 years) had AS/AI. Of these nine, four had symptoms and two had ECG abnormalities. The authors observed that the incidences of symptoms and ECG abnormalities were higher in the patients with AS than in those with AS/AI. There was no significant correlation between symptoms and ECG abnormalities with peak gradient, mean gradient, valve area, LV mass, volume, and mass/volume ratio in patients with AS/AI. However, significant correlation was found between symptoms and ECG abnormalities and ESWS in AS/AI patients. In conclusion, ECG abnormalities and symptoms do not always indicate the severity of AS and AS/AI.

Adolescent↗

PubMed1998

Congenital isolated apical ventricular septal defects.

The diagnosis of apical ventricular septal defects (VSDs) is difficult and the ratio of spontaneous closure is not well known. At the Ankara University Pediatric Cardiology Department, between the years 1992 and 1997, 33 patients were identified by color-flow Doppler (CFD) imaging as having a small defect at the apical portion of the ventricular septum. The age range was 1 day to 13 years. All patients were asymptomatic with normal telecardiograms and electrocardiograms. There were grade 2-3/6, pansystolic murmurs at the apex or closer to the apex in 19 patients. In 30 patients, narrow and short colored jets were seen at the apex of the heart, distal to the moderator band. The jets were wide in three patients. These defects were difficult to image and required specific angulation of the transducer. Of the 23 patients who had follow-up examinations, at 3 months to 3.5 years, there was spontaneous closure in ten (43.5%). To the authors' knowledge, this report is the largest series of isolated apical trabecular ventricular septal defects (t-VSDs). In their experience, color-flow imaging is more sensitive in detecting a small apical VSD. They conclude that although the closure of apical VSD is not the rule, the prognosis is excellent.

Adolescent↗

PubMed1998

Congenital complete atrioventricular block in an infant with long QT syndrome.

A three months old patient with congenital complete atrioventricular block and prolonged QT interval syndrome is presented. Before admission she had had two syncopal attacks. During hospitalization she had an episode of torsade de pointes which was followed by ventricular fibrillation. After a successful cardiopulmonary resuscitation, a permanent epicardial ventricular pacemaker was implanted and she was discharged on propranolol therapy. She is now free of symptoms and doing well, 16 months after discharge.

Adrenergic beta-Antagonists↗

PubMed1993

Congenital heart disease and Robinow syndrome.

We present a 6-month-old infant with Robinow syndrome and tricuspid atresia (type Ia). Up to now, at least 67 cases of Robinow syndrome have been published including nine cases with a congenital heart defect (CHD). As in our case, the majority of the CHD were right ventricular outflow obstruction. Robinow syndrome with CHD is not rare and in all cases of Robinow syndrome detailed cardiologic evaluation and echocardiography should be performed.

Abnormalities, Multiple↗

PubMed1990

The effects of caffeine and theophylline on the triple adenosine triphosphatase enzyme activities of spermatozoa from males with oligoasthenospermia.

The triple ATPase activities of washed spermatozoa of oligoasthenospermic men (but not of normals) were enhanced by the addition of caffeine and theophylline, which are known to have a stimulating effect on sperm motility. The biochemical mechanism of action of caffeine and theophylline on sperm homeostasis is discussed.

Adenosine Triphosphatases↗

PubMed1989

Hepatoma with right atrial extension.

The case is described of a 14-year-old boy who had a hepatoma with a right atrial extension. He presented with edema, abdominal pain, and ascites. Two-dimensional echocardiography showed a right atrial tumor that had invaded from the inferior vena cava as an extension into the right atrium of the hepatoma.

Adolescent↗

PubMed1989

The effect of spermine, spermidine and kallikrein on the triple adenosine triphosphatase enzyme activity of spermatozoa in males with oligoasthenozoospermia.

Unknown factors in the seminal plasma of normal semen that affect the motility of spermatozoa have a positive effect on adenosine triphosphatase (ATPase) enzyme activity. In an attempt to produce such an effect, spermine, spermidine and kallikrein were added to the incubation media in which spermatozoal ATPase enzyme activity was determined. These seminal substances increased the triple ATPase enzyme activity of spermatozoa from oligoasthenozoospermic men. We propose that the ATPase enzyme activity of spermatozoa may indicate sperm motility as a biochemical test.

Adenosine Triphosphatases↗

PubMedDate not supplied

Poststreptococcal reactive arthritis: clinical course and outcome in 15 patients.

Patients with Group A beta-hemolytic streptococcal infection and articular disease, who do not fulfill the modified Jones criteria for diagnosis of acute rheumatic fever (ARF), have been classified as having poststreptococcal reactive arthritis (PSRA). We reviewed the clinical characteristics, laboratory findings and outcome of 15 patients with PSRA. None of these patients had clinical evidence of carditis. The pattern of joint involvement was variable and included arthritis in five patients and arthralgia in the remaining ten patients. Nine patients were treated with salicylates for one to 16 weeks; the others recovered spontaneously. Usually, the patients with arthralgia responded promptly to salicylates, while the response was poor in patients with arthritis. One patient with monoarthritis developed carditis nine months after his first arthritis attack. Another patient presenting with monoarthritis later had two additional episodes of poststreptococcal reactive arthralgia. It seems there is a wide spectrum of poststreptococcal rheumatic diseases, and patients with PSRA are also at risk for cardiac disease; therefore, prophylactic antibiotic therapy should be considered in these patients.

Anti-Bacterial Agents↗