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Biomedical subjects

M Tuncer

Publications and source records attributed to M Tuncer.

At least 37 records · Page 2Linked to original sources
PubMed2003

Serum zinc and alkaline phosphatase values in pediatric bone marrow transplantation patients.

Zinc (Zn) plays an important role in the maintenance of immune functions, including cellular/humoral immunity, and in the prevention of oxidative injury. Therefore, the maintenance of a normal Zn status may be important in bone marrow transplantation (BMT) patients. Serum Zn levels were determined in 35 children during the BMT period. In addition, as Zn-related factors, serum Cu levels and alkaline phosphatase (AP) activity were also measured. There was a significant decrease in Zn and AP values during the immediate post-transplant period (lowest at day +7) when compared to pre-BMT levels (p <.01). The patients who developed hypozincemia were more likely to be transplanted for a diagnosis of malignant disorder and were younger, and adverse events appeared to occur more frequently. This preliminary study suggests that maintaining a normal Zn status may be important in BMT patients and that Zn deficiency may be a risk factor for adverse events.

Adolescent↗
PubMed2002

Degradation of lignocellulose by extracellular enzymes produced by Thermomonospora fusca BD25.

Degradation products from the addition of extracellular enzymes from Thermomonospora fusca BD25 to ball-milled wheat straw, oat spelt xylan and solubilised kraft pulps were characterised by HPLC and TLC. Overall, a high percentage hydrolysis of oat spelt xylan (28.9%) occurred after 26 h incubation. However, the rates of hydrolysis of ball-milled wheat straw and kraft pulp were approximately 4-6-fold less than xylan hydrolysis, although the total percentage hydrolysis of available substrate was similar (22.2% and 25.9% respectively). Incubation of kraft pulp and ball-milled wheat straw by crude extracellular enzymes of T. fusca BD25 resulted in the detection of aromatic compounds at concentrations of 0.6 microg ml(-1) and 8.7 microg ml(-1), respectively. Hydrolysis of oat spelt xylan by T. fusca BD25 extracellular enzymes yielded a mixture of xylose, xylotriose and putative substituted-xylotriose, while the products of ball-milled wheat straw hydrolysis were xylose, glucose and a small oligomer present in the digest. The results highlight the ability of culture supernatant from T. fusca to release both simple sugars and aromatic compounds from lignocellulosic substrates and suggest a role for this organism in the biobleaching of pulp.

Actinomycetales↗
PubMed2002

Impact of chronic renal failure and peritoneal dialysis fluids on advanced glycation end product and iNOS levels in penile tissue: an experimental study.

OBJECTIVES: To investigate the impact of chronic renal failure (CRF) on advanced glycation end product and inducible nitric oxide synthase (iNOS) in penile tissue, we examined the advanced glycation end product 5-hydroxy methyl furfural (5-HMF) content and iNOS expression in rats in which uremia had been produced by greater than 85% nephrectomy. In addition, the contribution of peritoneal dialysis (PD) fluids to the elevation of penile tissue 5-HMF levels and iNOS staining scores has been investigated. METHODS: Adult male Wistar rats, aged between 10 and 12 weeks and weighing 200 to 330 g, were divided into five groups that each included 6 animals. The first group served as a control group. In the second group, CRF was induced and a peritoneal catheter was implanted, but PD was not performed. In group 3, CRF was induced and PD was performed using dialysis fluids containing 1.36% glucose and icodextrin. In group 4, CRF was also induced and PD was performed using 3.86% glucose and icodextrin. Finally, in group 5, without CRF, an indwelling catheter was implanted, and the PD procedure was performed using dialysis fluids containing 3.86% glucose and icodextrin. RESULTS: The elevation in 5-HMF levels and iNOS staining scores in penile tissue from groups 2, 3, 4, and 5 was significant compared with group 1 (P <0.05). The elevation in 5-HMF levels and iNOS staining scores was also significant between groups 2 and 3, 2 and 4, 3 and 4, 3 and 5, and 4 and 5 (P <0.05). Moreover, the correlation between the 5-HMF levels and iNOS staining scores was statistically significant (r = 0.525, P = 0.003). CONCLUSIONS: In the present experimental study, we found that 5-HMF levels and iNOS staining scores were significantly elevated in rat penile tissue in which uremia had been produced compared with the groups without CRF. Additionally, PD fluids containing glucose had an effect on the elevation of penile tissue 5-HMF levels and iNOS staining scores.

Animals↗
PubMed2001

The analysis of eosinophil and lymphocyte phenotype following single dose of high-dose methylprednisolone in two siblings with marked hypereosinophilia.

The effect of single high-dose methylprednisolone (HDMP) on eosinophil and lymphocyte phenotype in two siblings with marked hypereosinophilia was investigated. Since conventional dose steroids failed to produce a haematological and clinical response in case one, both children were given HDMP (20 mg/kg/day). Eosinophils and lymphocytes showed an activated state before treatment, characterized by marked expression of CD11b, CD18, CD45RO on eosinophils and increased HLA-DR, CD95, CD18, CD38 on lymphocytes. Twenty-four hours after administration of HDMP a dramatic reduction in peripheral blood eosinophil count was observed in both patients associated with phenotypic changes characterized by decreased expression of CD11b, CD18, CD13 and increased CD95 expression in one. Furthermore, HDMP treatment induced a drop in the expression of CD95 and CD18 on lymphocytes. These changes may suggest a suppressive role for HDMP on eosinophil and lymphocyte activation which may have contributed to the haematological and clinical response.

Antigens, CD↗
PubMed2001

Clinical importance of serum vascular endothelial and basic fibroblast growth factors in children with acute lymphoblastic leukemia.

The aim of this study is to evaluate, for the first time serum levels of vascular endothelial growth factor (s-VEGF), and basic fibroblast growth factor (s-b FGF) in children with acute lymphoblastic leukemia (ALL), and its relation to clinical manifestations of the disease. Although VEGF and b FGF have been suggested to be reliable prognostic indicators and important tools for treatment approach in malignant haematopoietic and solid tumours, experience in childhood ALL has been limited to only one study on angiogenesis and urine b FGF. All 31 ALL patients included in the present study at the time of diagnosis and in remission, and all 10 control children had detectable serum levels of VEGF and b FGF. The median level of s-VEGF at the time of diagnosis was significantly lower than in the control group and at the time of remission (respectively p = 0.005, p = 0.0001). Twenty six of 31 patients had an increasing trend of s-VEGF levels in remission reaching control values compared with the levels obtained at diagnosis. S-b FGF median levels at the time of diagnosis were the same as those of the control group, significantly lower than the median s-b FGF values in remission (p = 0.001). In patients with lower platelet counts (< 50 x 10(9)/L) growth factors (VEGF and b FGF) were lower than in patients with higher platelet counts (p = 0.0009 and p = 0.002 respectively). In patients with hepatosplenomegaly (longitudinal size > 3 cm) b FGF levels were higher than patients without hepatosplenomegaly (P = 0.003). We concluded that the increment in both s-VEGF and s-b FGF in patients in remission may be related to the renewal of normal haematopoiesis. The increase in s-VEGF values in 26 out of 31 patients in remission compared to normal control values, may also suggest that there is clinical significance in ALL patients.

Adolescent↗
PubMed2001

Evaluation of children with myelodysplastic syndrome: importance of extramedullary disease as a presenting symptom.

Thirty-three children diagnosed with primary myelodysplastic syndrome (MDS) in a single institution over an 8 year period were evaluated with special emphasis on children who presented with extramedullary disease (EMD). EMD was present at diagnosis in 12 (36%) of the 33 children with MDS. Three patients with juvenile myelomonocytic leukemia (JMML) and 2 patients with chronic myelomonocytic leukemia (CMML) presented with pleural effusion. Pericardial effusion was present in 3 of these patients, two of whom also had thrombosis. Pyoderma gangrenosum, relapsing polychondritis were the initial findings in another two cases with JMML. Lymphadenopathy (n=1), gingival hypertrophy (n=2), orbital granulocytic sarcoma (n=1) and spinal mass (n=1) were the presenting findings in 5 patients with refractory anemia with excess of blasts in transformation. Since high-dose methylprednisolone (HDMP, 20-30 mg/kg/day) has been shown to induce differentiation and apoptosis of myeloid leukemic cells in children with different morphological subtypes of acute myeloid leukemia in vivo and in vitro, 25 children with de novo MDS were treated with combined HDMP and cytotoxic chemotherapy. Dramatic improvement of EMD and decrease in blast cells both in the peripheral blood and bone marrow were obtained following administration of short-course HDMP treatment alone as observed in children with AML. HDMP, combined with low-dose cytosine arabinoside and mitoxantrone were used for the remission induction. Remission was achieved in 8 (80%) of 10 children who presented with EMD and in 9 (60%) of 15 children without EMD. Long-term remission (>6 years) was obtained in 4 (two with JMML and two with CMML), three of whom presented with EMD. In conclusion EMD can be a presenting finding in childhood MDS as observed in adults. In addition, the beneficial effect of HDMP combined with more intensive chemotherapy should be explored as alternative therapy in children with MDS not suitable for bone marrow transplantation.

Adolescent↗
PubMed2001

Protective effect of lisinopril against ischemia-reperfusion injury in isolated guinea pig hearts.

BACKGROUND: In order to determine whether angiotensin-converting enzyme inhibitors (ACEI s) attenuate ischemia-reperfusion injury, we investigated and compared the effects of lisinopril via different routes of administration in an isolated guinea pig heart model of ischaemia reperfusion. METHODS: The effect of lisinopril cardioplegia, oral pretreatment with lisinopril and lisinopril enriched reperfusion solution on myocardium after a normothermic global ischemia of 90 minutes and 30 minutes of reperfusion in the modified Langendorff model was randomly studied in 4 groups (n=8 in each). In all groups, cardioplegic arrest was achieved by administering St. Thomas Hospital Cardioplegic Solution (STHCS). The first group was utilized as the control. In the second group, hearts were arrested with lisinopril (1 micromol/L) enriched STHCS. In the third group, animals were pretreated with oral lisinopril (0.2 mg/kg/twice a day) for ten days. In the last group hearts were again pretreated with oral lisinopril (like in Group 3) and the heart were reperfused with lisinopril enriched (1 micromol/L) Krebs-Henseleit solution during the reperfusion period. RESULTS: Contractility, which was expressed as contractile force (g contractility/g heart weight), was preserved better in the study groups. In the last group, the hearts had the best left ventricular contractile function, where contractile force was 58.4%+/-4.82% of the preischaemic values. In Group I, Group II and Group III they achieved 29.5%+/-5.6%, 41.9%+/-4.9%, and 55.3%+/-5.8% of their preischaemic contractile force values respectively. Creatine kinase leakage was significantly lower and also post- ischaemic coronary flows were significantly higher in the 4th group. Coronary flow after reperfusion increased from 48.0+/-6.2 to 68.0+/-4.51 ml/min.g.heart, in Group IV (p<0.05). CONCLUSIONS: Myocardial MDA and GSH contents showed that there was a correlation between the depletion of myocardial GSH content and increased lipid peroxidation. The myocardial GSH content indicates that the best results were obtained in the last group as compared to the other groups. These preliminary results showed that oral preconditioning improved postischaemic myocardial function and decreased myocardial injury. Because the best results were achieved in the last group, it can be suggested that lisinopril may also play a protective role against reperfusion injury.

Administration, Oral↗
PubMed2001

Relaxation induced by serotonin and sumatriptan in isolated guinea pig gallbladder strips.

The effects of 5-hydroxytryptamine (5-HT) and sumatriptan were investigated on isolated guinea pig gallbladder strips. While 0.1 microM-50 mM of 5-HT exhibited contractile and/or relaxant effects in quiescent preparations, the same concentrations of sumatriptan did not. On the other hand, carbachol-precontracted tissues were relaxed by the same amounts of 5-HT and sumatriptan in a concentration-dependent manner. The relaxant responses to 5-HT were not antagonized or changed by tetrodotoxin, indomethacin, capsaicin, NG-nitro-L-arginine (L-NOARG), GR55562 [(+/-)-propranolol, 3-[3-(N,N-dimethylamino)propyl 1-4-hydroxy-N-[4-(pyridin-4-yl)phenyl]benzamide , S(-)-propranolol, methysergide, ketanserin. tropisetron, GR 113808 ([1-[2-(methylsulphonylamino)ethyl -4-piperidinyl]methyl-1-methyl-1H-indole-3-carboxylate maleate salt). pargyline, and fluvoxamine. The relaxant responses to sumatriptan were antagonized by GR55562 but not by S(-)-propranolol. These results suggest that 5-HT and sumatriptan cause relaxation in carbachol-precontracted isolated guinea pig gallbladder strips by yet undefined mechanisms.

Adrenergic beta-Antagonists↗
PubMed2001

[Blindness as a complication of hepatic encephalopathy].

Hepatic (portal-systemic) encephalopathy is a complex neuropsychiatric syndrome characterized by disturbances in consciousness and behaviour, personality changes, fluctuating neurologic signs, asterixis or "flapping tremor" and distinctive electroencephalographic changes (11). We report a case of hepatic-encephalopathy accompanied by transient cortical blindness.

Adult↗
PubMed2000

T-ALL with monoclonal gammopathy and hairy cell features.

The presented case is a boy with T-cell acute lymphoblastic leukemia (ALL) with hairy cell (HC) features and monoclonal gammopathy. The disease process had an acute onset and followed a rapid, progressive course. The patient had minimal splenomegaly and bicytopenia, but the bone marrow displayed increased numbers of reticulin fibers. The blasts were positive for tartrate-resistant acid phosphatase (TRAP) and CD11c. Molecular analysis revealed rearrangement of immunoglobulin heavy chain genes and a rearranged T-cell receptor (TcRbeta) beta gene. The patient responded to conventional ALL therapy. Acute T-cell ALL with HC features in childhood has not been reported previously, either alone or in association with monoclonal gammopathy. We propose "T-ALL with hairy cell features" to describe this case.

Adolescent↗