Biomedical subjects

Ihsan Karadogan

Publications and source records attributed to Ihsan Karadogan.

4 recordsLinked to original sources

PubMed2006

rHuG-CSF increases the platelet-neutrophil complex formation and neutrophil adhesion molecule expression in volunteer granulocyte and stem cell apheresis donors.

Several reports have shown that granulocyte colony-stimulating factor (G-CSF) administration induces a transient, mild hypercoagulable state, which might predispose certain donors to thrombotic complications. In the present study, changes in the expression of neutrophil adhesion molecules (CD11b/CD18, CD62L) and platelet-neutrophil complex formation following rHuG-CSF administration were investigated in normal granulocyte and stem cell donors. For granulocyte apheresis (N = 10), rHuG-CSF (5 microg/kg) was given subcutaneously every 12 h three times and apheresis was carried out two hours after the last dose. For stem cell apheresis (N = 8), rHuG-CSF (10 microg/kg/day) was given subcutaneously for 5 days and apheresis was carried out when peripheral CD34+ cell counts exceeded 20 cell/microL. Expression of neutrophil adhesion molecules (CD11b/CD18, CD62L) and platelet-neutrophil complex formation following rHuG-CSF administration were investigated in donors by a flow cytometric method. A significant increase in neutrophil counts (P < 0.001), and decreases in platelet counts (P < 0.01) and hemoglobin levels (P < 0.01) occurred following G-CSF administration. The expression of CD11b/CD18 significantly increased (P < 0.001) over pretreatment values with G-CSF administration and returned to baseline 1 week after stopping the drug. In contrast, CD62L expression was decreased (P < 0.01) with G-CSF and returned to normal after cessation of the drug. rHuG-CSF caused more than a two-fold increase (from 0.3 to 7.0 x 10(9)/L) in circulating platelet-neutrophil complexes (P < 0.01), which returned to normal after 1 week. Although clinical significance of these laboratory changes is not clear, the occurrence of neutrophil activation and increased platelet-neutrophil complex formation might predispose certain donors or patients to thrombotic complications following G-CSF administration.

Adult↗

PubMed2006

Cytomegalovirus antigenemia and outcomes of patients undergoing allogeneic peripheral blood stem cell transplantation: effects of long-term high-dose acyclovir prophylaxis and preemptive ganciclovir treatment.

Cytomegalovirus (CMV) disease is a frequent cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation. In order to investigate the relationships between antigenemia, high-dose acyclovir (HDACV) prophylaxis, preemptive ganciclovir (GCV) therapy, and outcomes, we analyzed the records of 105 patients, including both pediatric and adult populations, who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) and who were at risk for CMV reactivation and disease (both recipient and donor seropositive). All received HDACV until neutrophil engraftment, but prophylaxis was continued till post-transplant day 180 only in pediatric patients in conjunction with weekly CMV pp65 antigenemia monitoring. Antigenemia-guided preemptive strategy with GCV was used for all patients. CMV antigenemia developed in 45 patients (42.9%) and CMV disease in 13 (12.4%). The frequencies for antigenemia were 31.3 and 63.2% in pediatric and adult groups (P = 0.002). All CMV diseases were in the adult group (P<0.001). Age at transplantation, underlying disease, long-term HDACV prophylaxis and acute graft versus host disease (aGVHD) were all found to be a significant risk factors for antigenemia. All of these factors other than aGVHD and conditioning regimen were also the significant risk factors for CMV disease. However, when we analyzed the pediatric and adult patients separately, dropping "long-term HDACV prophylaxis," none of these parameters were significant risk factors for CMV disease. In conclusion, we hypothesize that long-term HDACV prophylaxis in the GCV era results in a low incidence of CMV reactivation and disease in patients undergoing PBSCT.

Acyclovir↗

PubMed2004

Peritoneal macrophages function modulation by L-carnitine in aging rats.

BACKGROUND AND AIMS: The aging process is associated with a progressive decline in physiological functions involving immune response in most species. The aim of the present study was to determine the effect of L-carnitine on impaired macrophages function in aged rats. METHODS: Superoxide anion production, chemotaxis and phagocytic activity were studied in peritoneal macrophages obtained from young (2 months old) and aged (24 months old) rats. L-carnitine (50 mg/kg bw) or control vehicle was orally gavaged into young and aged rats for 30 consecutive days. RESULTS: The peritoneal macrophages of the aged rats exhibited an increase in superoxide anion generation and a decline in chemotaxis and phagocytic index by comparison with the young rats. Superoxide anion production in aged rats was significantly reduced by L-carnitine treatment, as accompanied by a significant enhancement of chemotactic activity, which was restored to control levels observed in young rats. The age-related reduction in phagocytic index was only slightly, but not significantly, restored by L-carnitine administration, however. CONCLUSION: The findings suggest that L-carnitine administration may be useful in reversing some age-related changes.

Aging↗

PubMed2002

Apoptosis of cord blood neutrophils and their response to colony-stimulating factors.

Neutrophil production and functions are immature in newborns. Although neutrophil kinetics during neonatal period have been widely studied, little is known about the effect of apoptosis on these defects. In this study, we examine the apoptosis of neonatal neutrophils and the effects of colony-stimulating factors (CSF) on this process. The study was performed using three different methodologies (morphological analysis, surface Fas expression, and mitochondrial 7A6 antigen expression) and the results were compared with adult controls. Neonatal neutrophils more rapidly underwent apoptosis in comparison to adult neutrophils. The above-mentioned three different methods gave similar results. Granulocyte-CSF (G-CSF) and granulocyte-macrophage CSF (GM-CSF) decreased the apoptosis of neutrophils in newborns and adults. This effect was significantly more pronounced in adults than newborns in morphological analysis. Increased apoptosis may contribute to qualitative and quantitative defects of neutrophils during neonatal period and may be an explanation for the proneness of newborn to develop neutropenia during systemic infections.

Adult↗