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Biomedical subjects

K Baysal

Publications and source records attributed to K Baysal.

At least 37 records · Page 2Linked to original sources
PubMed1991

Regulation of the mitochondrial Na+/Ca2+ antiport by matrix pH.

The effect of matrix pH (pHi) on the activity of the mitochondrial Na+/Ca2+ antiport has been studied using the fluorescence of SNARF-1 to monitor pHi and Na(+)-dependent efflux of accumulated Ca2+ to follow antiport activity. Heart mitochondria respiring in a KCl medium maintain a large delta pH (interior alkaline) and show optimal Na+/Ca2+ antiport only when the pH of the medium (pH0) is acid. Addition of nigericin to these mitochondria decreases delta pH and increases the membrane potential (delta psi). Nigericin strongly activates Na+/Ca2+ antiport at values of pH0 near 7.4 but inhibits antiport activity at acid pH0. When pHi is evaluated in these protocols, a sharp optimum in Na+/Ca2+ antiport activity is seen near pHi 7.6 in the presence or absence of nigericin. Activity falls off rapidly at more alkaline values of pHi. The effects of nigericin on Na+/Ca2+ antiport are duplicated by 20 mM acetate and by 3 mM phosphate. In each case the optimum rate of Na+/Ca2+ antiport is obtained at pHi 7.5 to 7.6 and changes in antiport activity do not correlate with changes in components of the driving force of the reaction (i.e., delta psi, delta pH, or the steady-state Na+ gradient). It is concluded that the Na+/Ca2+ antiport of heart mitochondria is very sensitive to matrix [H+] and that changes in pHi may contribute to the regulation of matrix Ca2+ levels.

Acetates↗
PubMed1991

Diagnostic value of integrated ultrasonic backscatter in congestive cardiomyopathy.

Congestive cardiomyopathy is a fatal myocardial disease which can be diagnosed by clinical findings, electrocardiography, roentgenography and echocardiography. Tissue characterization and pathology have been determined recently using histogram methods to analyze ultrasonographs. In this study ultrasonic backscatter analysis for differentiation of normal and diseased myocardium was tested. Two-dimensional echo data and radio frequency signals of long-axis views of the left ventricular posterior wall of 10 healthy children and 14 patients with congestive cardiomyopathy in systolic and diastolic phase were digitized online into the computer memory. Cyclic variation was obtained in the control group but no variation was detectable in myopathic hearts.

Cardiomyopathy, Dilated↗
PubMed1991

[The value of laboratory tests for the early diagnosis of newborn sepsis].

In our study, laboratory tests were evaluated in the early diagnosis of newborn sepsis. The study consisted of 53 newborn infants with the diagnosis of suspected sepsis. Of the 53 newborn infants twenty seven were excluded from the study, because of negative blood culture. Remaining 26 newborns with positive blood culture and 15 healthy newborns comprised the study (sepsis group) and control group respectively. Total mature neutrophil count, immature/total neutrophil and immature/matür neutrophil ratio, toxic granulation changes, serum level of C-reactive protein and haptoglobin were found statistically higher in sepsis group than control group. Thrombocyte count and serum level of IgG were significantly lower in sepsis group. Average total white blood cell count, result of nitroblue tetrazolium tests erythrocyte sedimentation rate and serum level of IgM was similar in both groups. We emphasized that hematological scoring system, serum level of C-reactive protein and haptoglobins can be used in the early diagnosis of newborn sepsis.

Bacteremia↗
PubMed1989

Liver gamma-glutamyl transpeptidase activity following chronic treatment with acetylsalicylic acid in rats.

In the present study, rats were administered acetylsalicylic acid (ASA), at low and high doses, by means of a gastric tube for 30 days. Chronic administration of a high dose of ASA (200 mg/kg body weight) resulted in a significant increase in liver plasma membrane gamma-glutamyl transpeptidase activity, cholesterol, and phospholipid levels. The enzymatic activity and lipid levels appeared not to be affected by ASA when given at a lower dose (50 mg/kg body weight). The changes in the enzymatic activity of plasma membrane were positively correlated to membrane cholesterol content. These findings suggest that the hepatotoxicity of high doses of ASA should not be overlooked during clinical use of the drug.

Animals↗
PubMed1988

Balloon atrial septostomy using echocardiographic monitoring.

Six patients with d-transposition of the great arteries and 1 patient with tricuspid atresia were diagnosed echocardiographically. Balloon atrial septostomy (BAS) was performed successfully in all cases with the aid of two-dimensional echocardiography. Echocardiography may be superior to fluoroscopy during BAS because it permits easy detection of spontaneous passage of the inflated catheter into the left ventricle spontaneously through the mitral valve (like a left atrial myxoma). With the visualization of related cardiac structures during BAS, obstruction of the IVC with the balloon was also prevented. Using this method, bedside application of BAS is possible.

Catheterization↗
PubMedDate not supplied

Two-dimensional ultrasonographic findings of atelectatic lung segments.

Thirteen cases with pulmonary atelectasis were examined by two-dimensional sonography in our clinics between October 1990 and April 1993. Patients' ages ranged from 2 to 16 years. Five patients revealed atelectasis with pleural effusion and eight patients had only atelectasis. Two-dimensional sonography showed a solid mass indistinguishable from lung parenchyma in patients with atelectatic lung segment without pleural effusion while atelectatic segment was readily identified in those with pleural effusion. We conclude that sonography is a useful and non-invasive technique in differentiating cardiac from extracardiac masses, because atelectatic lung segment with moderate to large pleural effusion may mimic intrapericardial masses.

Adolescent↗
PubMedDate not supplied

High association of congenital heart disease with indirect inguinal hernia.

We evaluated 103 patients with indirect inguinal hernia (IIH) for the association of congenital heart disease by echocardiography. Congenital cardiac abnormalities were recognized in 32% of patients with inguinal hernia, which is significantly higher than that reported in a population-based study in Turkey and other population-based studies. Ventricular septal defect and valvular anomalies are the most frequently detected malformations. Our findings suggest that screening for congenital hearth disease is necessary in children with indirect inguinal hernia.

Child, Preschool↗
PubMedDate not supplied

Cardiac functions in children with vitamin D deficiency rickets.

Nutritional deficiency of vitamin D is common in developing countries as a result of both inadequate diet and exposure to ultraviolet light. The most striking biochemical finding in this illness is hypocalcemia. Reduction in serum calcium level may affect ventricular contraction. The purpose of this study was to evaluate prospectively left ventricular function in a group of 27 infants diagnosed as having rickets. Electrocardiograms and echocardiographic studies were undertaken in all patients. A group of ten healthy infants was used as a control for the echocardiographic examinations. Patients were divided into three groups according to the biochemical classification of rickets. There were eight patients in group I, nine in group II, and ten in group III. Abnormal electrocardiographic findings were noted in four infants in group I, three in group II, and six in group III before treatment of the rickets. These changes resolved following treatment. Echocardiographic studies revealed left ventricular dysfunction in the pretreatment stage. The most striking echocardiographic finding is the increase in the ratio of interventricular septal thickness to left ventricular posterior wall thickness in eight patients from group III. This returned to normal after treatment of the rickets. This study has demonstrated echocardiographic evidence of left ventricular dysfunction in children with rickets. These abnormalities were not, however, sufficiently severe to be associated with clinical signs of cardiac failure. Cardiomyopathy may develop in rickets, especially in the third stage of the disease, and this finding may return to normal following adequate treatment of the rickets.

Chi-Square Distribution↗
PubMedDate not supplied

Magnetic resonance imaging of proximal aortopulmonary window.

Aortopulmonary window was prospectively diagnosed by magnetic resonance imaging in a 9-month-old boy. The diagnosis was confirmed by cardiac catheterization, angiocardiography, two-dimensional and color doppler echocardiography. Spin-echo T1-weighted axial and coronal magnetic resonance images show a large windowlike communication between left ascending aorta and right wall of the main pulmonary arterial trunk. To our knowledge, this is the first time that the diagnosis of the aorticopulmonary window was achieved by magnetic resonance imaging.

Angiography↗
PubMedDate not supplied

Oestrogen receptors and cardiovascular disease.

1. Animal and human studies indicate that female sex hormones are protective against the development of coronary atherosclerosis. 2. Experiments on vascular smooth muscle cells suggest a direct effect of oestrogen on vascular tissue. Although oestrogen receptors (ER) in vascular tissues and an association between ER stimulation and physiological effects have been demonstrated, the cellular mechanisms underlying the effects of oestrogen on the arterial wall remain to be defined. 3. Elucidation of the cellular mechanism underlying the effects of oestrogen on vascular smooth muscle will provide insights into coronary atherosclerosis and will provide an opportunity to apply the protective effects of oestrogen to women in older age groups and to the male population.

Animals↗
PubMedDate not supplied

Ophthalmic and central retinal artery flow velocities in patients with Behçet's disease.

Vascular involvement is a well known manifestation of Behçet's disease (BD) and may effect systemic and regional circulation in patients with BD. We evaluated ophthalmic and central retinal artery flow velocities in these patients. Mean ophthalmic and central retinal artery flow velocities were lower in patients with BD than in healthy controls, but the cause and significance of these findings remain to be defined.

Adolescent↗
PubMedDate not supplied

Extrapontine myelinolysis in a nine-year-old child.

Extrapontine myelinolysis in the pediatric age group is very rare. We report a nine-year-old girl with the classical clinical syndrome of pontine and extrapontine myelinolysis following liver trauma due to a traffic accident. She was referred to our hospital for further investigation of convulsions due to severe postoperative hyponatremia. She had no hypoxic event or other identifiable cause for the neurological symptoms. Neurological deterioration began about two days after correction of hyponatremia and followed a period of temporary improvement in hyponatremic encephalopathy. Diagnosis of extrapontine myelinolysis was confirmed with the identification of typical features on magnetic resonance imaging. The rapid correction of hyponatremia seemed the most likely cause since other biochemical tests including liver function tests were all within normal ranges. The long term clinical outcome was good. It is important to carefully monitor the rate of correction in electrolyte disturbances, and to consider the individual variation in response to therapy.

Accidents, Traffic↗
PubMedDate not supplied

Atrial septal aneurysm in children.

Atrial septal aneurysm (ASA) has rarely been described in children. In this study, we evaluated the incidence and natural course of this anomaly in children. ASA was found in 30 patients (1%); 16 patients had type 1R and 14 patients had type 2L ASA. Twenty patients with ASA were followed: in four the ASA disappeared and in three patients with type 2L an atrial septal defect (ASD) developed during follow-up. The most common associated lesion was patent foramen ovale (PFO). We conclude that ASAs in children are not rare lesions, and that these aneurysms, particularly type 2L aneurysms, should be followed for occurrence of ASD.

Child↗
PubMedDate not supplied

Effect of acetylsalicylic acid on liver plasma membrane Ca2+ ATPase activity.

In the present study, the effects of low- and non-toxic high doses of acetylsalicylic acid (ASA) on liver plasma membrane Ca2+ ATPase activity and also on some membrane lipid components were investigated in rats. ASA was administered to rats by means of a gastric tube at doses of 50 mg/kg and 200 mg/kg, daily, for 30 days. Chronic oral administration of high dose of ASA resulted in significant increases in liver plasma membrane cholesterol and phospholipid levels, whereas the membrane lipids appeared not to be affected by low dose of ASA. Liver plasma membrane Ca2+ ATPase activity was found to be significantly inhibited following high dose of ASA treatment. Low dose of ASA administration caused a slight, but non-significant decrease in enzyme activity. It is concluded that the inhibition of Ca2+ ATPase activity produced by high dose of ASA treatment may be expected to cause Ca2+ accumulation in liver cells, thereby leading to the cell injury.

Animals↗
PubMedDate not supplied

Percutaneous transluminal balloon pulmonary valvuloplasty: immediate and medium-term results.

Ten patients with pulmonary stenosis, (six males and four females) whose ages ranged between five and ten years (mean age 7 years) underwent cardiac catheterization and balloon valvuloplasty. Right ventricular systolic pressure before valvuloplasty ranged from 90 to 200 mm Hg (mean 133.5 +/- 33.3 mm Hg). It fell to 50-90 mm Hg (mean 64.5 +/- 13.8 mm Hg) immediately after the procedure. The peak systolic gradient across the pulmonary valve before valvuloplasty ranged from 70 to 180 mm Hg (mean 114.5 +/- 35.4 mm Hg) and decreased significantly to 30-70 mm Hg (mean 43.0 +/- 13.8 mm Hg) immediately after dilation. Doppler echo studies confirmed these results. At repeat cardiac catheterization in three patients, five to 15 months after valvuloplasty, restenosis was noted in one patient while there was no change in the others. All patients had been followed up by Doppler echocardiography. Patients with isolated valvular pulmonary stenosis can be adequately and safely treated with balloon valvuloplasty which results in excellent immediate and medium-term results.

Catheterization↗
PubMedDate not supplied

Peripheral vein contrast echocardiography in atrial septal defect.

This study was carried out on 233 children suspected clinically of having atrial septal defect with the aim of investigating the diagnostic capability of peripheral venous contrast echocardiography. The transfer of contrast material from the right atrium into the left atrium was evaluated as "positive contrast", while noncontrast blood, passing from the left atrium into the right atrium was termed "negative contrast". Positive contrasts were quantitated in four grades. A significant negative contrast effect was graded 3- or 4-. Three positive, 4+ and/or 3-, 4- contrast effects were considered definite evidence of an atrial septal defect. Among the cases with the above findings 92 underwent surgical closure of atrial septal defect. The procedure was successful in all patients operated; the size of the defect was large. This result demonstrates that the method applied is a safe and reliable one. However, in a group of cases without the above echocardiographic findings the presence of an atrial septal defect was detected by cardiac catheterization and angiocardiography. Therefore, we can conclude that the method applied is not a sensitive, but a specific one, for definite detection of atrial septal defect.

Adolescent↗