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Biomedical subjects

H Okur

Publications and source records attributed to H Okur.

At least 19 recordsLinked to original sources
PubMed2005

High cystine in platelets from patients with nephropathic cystinosis: a chemical, ultrastructural, and functional evaluation.

AIM: To investigate the morphology and function of platelets in nephropathic cystinosis (NC). METHODS: Seven patients (mean age, 6.5 years; SD, 20 months) with NC were investigated. Their platelets were examined by transmission electron microscopy (TEM) and the characteristics of the dense granules (DGs) were determined by mepacrine labelling and the uranaffin reaction. Bleeding time, turbidometric aggregation, and luminescence aggregation were studied and intraplatelet cystine was measured. RESULTS: Increased intraplatelet cystine, primary and secondary aggregation defects, and the absence of ATP release were demonstrated. TEM revealed DGs of various shapes and sizes and lamellary or amorphous cytoplasmic inclusions. Viscous material had been released into the vacuolar spaces and enlarged open canalicular system. Mepacrine labelling revealed that the numbers of DGs/platelet were comparable between the patients and the controls (mean, 2.9 (SD, 0.22) v 3.32 (0.18); p = 0.34). The uranaffin reaction revealed that the numbers of type 1, 3, and 4 DGs were comparable between the patients and the controls, but that there were fewer type 2 DGs in the patients (mean, 8.5 (SD, 1.95) v 17.22 (1.58); p = 0.01). TEM for platelet aggregation revealed a lack of induction and/or defective execution and/or delayed transmission. The patients' intraplatelet cystine concentrations were higher than the controls (mean, 1.56 (SD, 0.84) v 0.08 (0.01) nmol/mg protein; p = 0.009). CONCLUSIONS: This is the first report to demonstrate raised intraplatelet cystine, abnormal platelet ultrastructural findings, and defective aggregation in NC.

Adolescent↗
PubMed2003

The effects of high dose methylprednisolone on apoptosis in children with acute lymphoblastic leukemia.

Rapid leukemic cell kill at initial diagnosis of patients with acute lymphoblastic leukemia (ALL) has been shown to be associated with a favorable outcome. The aim of the present study was to investigate the effect of high dose methylprednisolone (HDMP) on in vivo blast cell apoptosis in children with ALL. Annexin V-binding and Fas (CD95), Fas ligand (FasL; CD95L), and Bcl-2 expression in PB blasts were determined in newly diagnosed children with ALL before and 4, 24, 96 h after initiation of HDMP treatment (n=20) or conventional dose steroids (CDS) (n=10) as the control group. A decrease in absolute blast count (from 40.8 x 09 to 21.4 x 109/l) associated with an increase in apoptosis (14.2 to 26.9%) (P < 0.05) was detected 4 h after initiation of HDMP. A significant increase in Fas and FasL expression was detected 96 h after HDMP. There was no significant change in apoptosis, Fas and FasL expression from baseline in the control group treated with CDS. The changes in Bcl-2 expression after treatment was not significant in both groups. The results of this preliminary study have shown that HDMP treatment was effective in inducing immediate (within 4 h) blast cell apoptosis. The contribution of Fas/FasL interaction in the rapid component of cell kill remains to be determined, as the increase in the expression of these molecules was evident later.

Apoptosis↗
PubMed2001

Impact of stress, gender and menstrual cycle on immune system: possible role of nitric oxide.

Stress is a factor found to be involved in the etiology of many diseases. Gender and menstrual cycle phases are other factors affecting the predisposition of individuals for certain diseases. Results from animal and human studies suggest that the distribution of immune system cells may change at different phases of the menstrual cycle. Acute mental stress in humans alters immune variables, too. The increase in the number of natural killer (NK) cells is the most consistent finding among the immune variables, though there are controversies for the other lymphocyte groups. Nitric oxide (NO) as an immune mediator has an unsettled role whether it causes the redistribution of the immune cells, or is an end product of lymphocyte activation. This study was planned to investigate the effect of mental stress on lymphocyte subtypes and the role of NO, for men and women at different phases of the cycle. For this purpose, healthy men (n = 10) and women (n = 10), during the follicular and luteal phases underwent Stroop colour-word interference and cold pressor tests. The immune system responses before and after the tests were determined by cell counts with the flowcytometer. Menstrual cycle phase was ascertained by plasma estrogen and progesterone measurements. Stress response was evaluated by blood pressure (BP) and heart rate (HR) measurements throughout the tests and plasma cortisol and urinary metanephrine and vanillylmandelic acid (VMA) measurements before and after the tests. Plasma and urinary NO determinations were performed before and after the test was completed. All the results were analysed with the appropriate statistical methods. The luteal phase differed from the other groups due to the presence of suppressed immune response to acute stress, including decreased CD4/CD8 ratio and NK cell percentage. On the other hand, acute stress caused a shift from cellular to humoral immunity in men. As indicated by these results, individual reaction towards stress is affected by gender and menstrual cycle phase. NO appears to be a possible effector molecule for these differences.

Adult↗
PubMed2000

Dysplastic changes in idiopathic thrombocytopenic purpura and the effect of corticosteroids to increase dysplasia and cause hyperdiploid macropolycytes.

This study evaluates the dysplastic hematological changes in nine patients with idiopathic thrombocytopenic purpura (ITP) in 11 attacks, before and after corticosteroid treatment. The pretreatment blood smears of patients with ITP, displayed more neutrophils with bizarre nuclei (P < 0.001), Döhle or Döhle-like inclusions (P < 0. 01), irregular distribution of granules (P < 0.05), hypo-agranulation (P < 0.05), pseudo-Pelger-Huet-like cells (P < 0. 01), and nuclei with chromatine clumping (P < 0.01) than the normal children. The eosinophils of ITP patients were also dysplastic, before treatment. The pretreatment diameter of the neutrophils and the percentage of macropolycytes were greater than those of the patients with viral infections and normal group (P < 0.05 for all). The percentage of neutrophils with bizarre nuclei and nuclei with chromatine clumping and the diameter of neutrophils and macropolycyte percentage increased with corticosteroid therapy (P < 0.01, < 0.01, < 0.01, and < 0.05, respectively). The neutrophil diameter, percentage of macropolycytes, and number of neutrophils with bizarre nuclei decreased within 1-4 weeks after the therapy was stopped. In the neutrophils of two patients, diploidy and hyperdiploidy were established before and on the last day of therapy, respectively, and diploidy reversed after therapy was stopped. In conclusion, ITP patients display dysplastic findings in both neutrophils and eosinophils before treatment and corticosteroids cause transient significant increase in some of the dysplastic changes in neutrophils.

Adolescent↗
PubMed2000

Corrosive injuries of the esophagus in newborns.

To evaluate the morbidity and mortality of corrosive esophageal injuries (CEI) in the neonatal period, the records of 184 children hospitalized following caustic ingestion over a 10-year period from January 1987 to November 1997 were reviewed. Eight (4.3%) were newborns (5 boys and 3 girls). The mean age of the newborns was 12 days (range 1-28). The ingested caustic materials were benzalkonium chloride in six patients and trichloroacetic acid in two. Oropharyngeal examination and esophagoscopy were performed for diagnosis. Hyperemia and fibrin plaques were present in the oropharynx in all patients. The management consisted of endotracheal intubation, antibiotics, corticosteroids, and total parenteral nutrition. Pneumonia and sepsis developed in three patients and one died of sepsis. Stenosis developed in two patients, who were treated three times with antegrade dilatations. The morbidity was 62.5% (five patients) and the mortality was 12.5% (one) in newborns with CEI. These results indicate that ingestion of a caustic substance results in high morbidity and mortality in newborns. Parents and nurses should be warned about this risk.

Benzalkonium Compounds↗
PubMed2000

Urolithiasis in childhood.

A retrospective review was performed of the records of 85 children with urinary-tract calculi evaluated and treated during a 12-year period. The study evaluated the patients' age, sex, initial complaints, etiology, relevant pathological factors, stone location, mode of treatment, and stone analysis. There were 68 boys and 17 girls, a ratio of 4:1. Patient age ranged from 10 months to 16 years (average 8.2 years). Flank pain was the most common manifestation. Seventy patients had calculi in the upper urinary tract and 31 in the lower urinary tract; 16 had stones in more than one site and 15 had bilateral stones. Hypercalciuria was the most common metabolic disorder. Most patients underwent open surgical procedures for removal of their calculi; 5 stones were successfully removed endoscopically. In 3 cases, the stones passed spontaneously. Calcium oxalate and calcium phosphate stones were present in 32 cases, struvite in 5, cystine in 2, and uric acid in 1 Urolithiasis is still one of the most common pediatric urologic problems in Turkey, but as living standards improve, the incidence of the disease has tended to decline in recent years. Anatomic anomalies and metabolic disorders are of great importance in the etiology of stone disease.

Adolescent↗
PubMed2000

CD34/CD117 co-expression in childhood acute leukemia.

CD117 protein is expressed by the primitive CD34 positive haemopoietic stem cells and also demonstrated on the blasts of 30-100% of AML cases, but rarely on lymphoblasts. Therefore several investigators have used CD117 expression to exclude lymphoblastic origin of blasts. However, conflicting results exist in the literature. We investigated CD34 and CD117 status at initial presentation of 232 children with acute leukemia. CD34 was commonly expressed in all types of acute leukemias, whereas CD117 molecule seemed to be a more specific marker for leukemia of myeloid origin being demonstrated on > 5% of blasts in 60 out of 73 cases of AML patients, but rarely detected in ALL (9/140 patients). Moreover, co-expression of CD34/CD117 was extremely rare on lymphoblasts with only 3/140 ALL patients demonstrating > 5% co-expression of CD34 and CD117, and therefore we suggest that it should be used in the exclusion of ALL.

Adolescent↗
PubMed1999

Effects of methylprednisolone on human myeloid leukemic cells in vitro.

We have demonstrated previously that high-dose methylprednisolone treatment induces differentiation and apoptosis of leukemic cells in patients with different morphological subtypes of acute myeloblastic leukemia (AML) in vivo. In the present study, we investigated the in vitro effects of high (10(-3) M) and low (10(-6) M) concentrations of methylprednisolone (MP) on freshly isolated bone marrow leukemic cells from nine newly diagnosed patients with AML by light and electron microscopy (EM) and agarose gel electrophoresis. A marked increase in MP-induced apoptosis of leukemic cells, with a maximum effect at 24 hr of exposure to both low and high concentrations of MP (10(-6) M and 10(-3) M), was demonstrated by light microscopy in cultures of four (three with AML-M1 and one with AML-M7) of the nine patients. In three cases, the increase in the number of apoptotic cells induced by high-concentration MP was approximately twice that observed when the lower concentration was used. A few apoptotic cells were detected in the cultures from the other five patients. However, a typical DNA ladder pattern of apoptosis was observed on gel electrophoresis of MP-treated leukemic cells from one patient (AML-M1) after 2 hr of incubation with both high- and low-MP concentrations. In two patients, a nonspecific DNA smear was observed only when high-concentration MP was used. The increase in differentiated leukemic cells induced by MP was also dose dependent, and was observed in cultures from all but one patient. Morphological features of apoptosis and differentiation were also confirmed by EM studies. The results of the present study, together with our previous clinical experience, suggest that MP, especially at high doses, could have a significant role in the treatment of some AML patients by inducing apoptosis and differentiation of leukemic cells.

Adolescent↗
PubMed1999

[Help in explaining to Turkish-speaking patients about the central affects of pharmaceuticals. Fact or fiction?].

Handouts in their mother tongue might be helpful in informing patients who do not speak German about medications that are prescribed. A survey among 97 producers of CNS active drugs used in neurology and psychiatry showed that only two patient information leaflets on preparations and nine on specific disorders are available in Germany. The producers who answered were mostly open-minded and mentioned causes like the legal situation and logistic problems.

Central Nervous System Agents↗
PubMed1999

The importance of cell size and surface marker analysis in childhood acute myeloblastic leukemia.

In order to evaluate the prognostic significance of cell size and surface marker expression, we evaluated 33 children with newly diagnosed acute myeloblastic leukemia by flow cytometry. We determined: the percentage of small, middle and large cells; large to small cell ratios (LS); large plus middle to small cell ratios (LMS); the percentage of surface markers expressed by each group of cell; the ratios of surface marker percentages expressed by the large blasts to that expressed by small blasts (LS for surface markers); and large plus middle blasts to that by small blasts (LMS for surface markers). For 'early prognosis', patients who could and could not achieve remission (n = 23 and 10) and for late prognosis, the patients who deceased or relapsed within the first 12 months of the treatment (n = 24) and who survived for more than 12 months (n = 9) were compared, in two classifications. CD3 percentages of the small cells of alive patients were significantly higher than that of dead or relapsed patients. LMS for CD3 and CD20 and LS for CD20 were higher in dead relapsed patients than that of alive patients. The total percentage of CD14 was significantly higher in dead relapsed patients than it was in the alive patients and CD3 was significantly higher in the group of patients who achieved remission than that of the patients who could not achieve remission. It was striking that, expression of CD3, CD7, CD22, CD33, CD14, CD15, CD34 increased or decreased as to cell size, whatever the prognosis. CD10, CD20 and CD13 were expressed on the large cells of the patients who could not achieve remission or died relapsed. We showed that, the blast cell size, individually does not have any prognostic significance in childhood AML and the prognostic significance of surface markers not only depends on their presence or absence but also on their relative configuration of expression by the blasts with different size.

Adolescent↗
PubMed1999

Changes of hemostatic factors in children with acute lymphoblastic leukemia receiving combined chemotherapy including high dose methylprednisolone and L-asparaginase.

In this study, protein C (PC), protein S (PS), heparin cofactor II (HCFII), prothrombin fragment 1+2 (PF 1,2), thrombin-antithrombin III complex (TAT), von Willebrand factor (vWF) and thrombomodulin (TM) were investigated in 19 patients with acute lymphoblastic leukemia, (ALL) receiving combined chemotherapy including L-asparaginase (L-ASP) and high dose methylprednisolone (HDMP). HDMP was administered in doses of 30 mg/kg/day for 7 days, and 20 mg/kg/day for another 7 days. In order to evaluate the effect of HDMP on the hemostatic system, the 8 patients studied here received HDMP (30 mg/kg/day) therapy for 4 days before the combined chemotherapy. These parameters were also studied in 12 healthy children as a control group. PC levels were normal in the patients while PS levels were decreased both before and after combined chemotherapies. Patients with ALL have laboratory signs of coagulation activation such as PF 1,2, TAT prior to initiation of chemotherapy. With combined chemotherapy, TAT levels were found to be normal while PF1,2 were not. TM levels were found to be increased both before and after therapies whereas HCFII and vWF levels were not different from those of the control group. The short course of HDMP therapy did not prominently influence these hemostatic parameters. These results indicate that both the malignant process and the drugs used in combined chemotherapy cause a decrease in natural inhibitors and an increase in procoagulant activity and endothelial injury. These hemostatic changes may contribute to a thrombotic tendency in the patients with ALL.

Adolescent↗
PubMed1998

Comparison of nitric oxide production by monocyte/macrophages in healthy subjects and patients with active pulmonary tuberculosis.

The aim of the present study was to determine the NO production by human cultured macrophages (m phi) and to compare the NO production between healthy subjects and patients with active pulmonary tuberculosis. The bioassay method was used for assessment of validation. Lipopolysaccharide (125 ng ml-1)-activated m phi from healthy and diseased subjects released a substantial amount of NO. NO synthase inhibitor, NG-nitro-L-arginine methyl ester, (0.1 mmol l-1) suppressed NO synthesis significantly in m phi of healthy subjects. Nitrite formation measured by the diazotization method in the supernatants taken from cultured m phi of tuberculous patients were significantly lower than the healthy subjects. The supernatants obtained in both subjects caused relaxation of guinea-pig aorta reversed by methylene blue (10 mumol l-1). There was a significant difference between relaxations of healthy and diseased supernatants. Nitrite formation measured by the bioassay method in the supernatants taken from cultured m phi of tuberculous patients was significantly higher than the healthy subjects. It was concluded that NO production appeared to be decreased in tuberculosis. The reason for decreased production of NO in tuberculosis may be related to the interaction of several cytokines and/or eicosanoids by means of the disease related induction of immune reactions.

Adult↗
PubMed1998

Malformation of the epididymis in undescended testis.

During a 6-year period, 312 boys (mean age 4.7 years) underwent orchidopexy for cryptorchidism. A total of 388 epididymides were examined and the configurations were recorded as a prospective trial. This study consists of 166 ectopic testes and 222 undescended testes. The observed configurations of epididymides in the ectopic testes were: type 1a in 99 cases (59.6%), type 1b in 35 (21.1%), type 2 in 24 (14.5%), type 3 in 7 (4.2%), and type 4 in 1 (0.6%). There were no patients in the study with type 5 and 6 anomalies. The configurations of epididymides in the undescended testes were: type 1a in 105 (47.3%), type 1b in 63 (28.4%), type 2 in 26 (11.7%), type 3 in 13 (5.9%), type 4 in 5 (2.3%), type 5 in 7 (3.2%), and type 6 in 3 (1.4%). The data revealed that the incidence of epididymal abnormalities in undescended testes (41%) was higher than that in the ectopic testes (25.9%) (P < 0.05).

Adolescent↗
PubMed1998

Effect of an alum-containing mouthrinse in children for plaque and salivary levels of selected oral microflora.

The purpose of the study was to assess the effect of daily supervised rinsing with a specially formulated, alum-containing mouthrinse on plaque and salivary levels of S. mutans, S. mitis and S. salivarius in caries susceptible children (12-14 years old) and to monitor the effect on the oral tissues and acceptability to subjects. Forty-five subjects were divided into 3 groups (n = 15). Group I received an experimental group with a mouthrinse containing hydrated aluminum potassium sulfate (alum). Group 2 received a vehicle control group containing the same mouthrinse, but without alum and Group 3 had a treatment control with distilled water. All subjects continued normal oral hygiene habits during the study. Salivary and plaque levels were obtained at base line, 2 weeks and 4 weeks and evaluated for microbiologic procedures. Also, potential adverse effects on oral tissues were performed during every visit. The mean plaque and salivary levels of oral Streptococcus (S. mutans, S. mitis, S. salivarius) for the experimental group were significantly reduced after 2 weeks and 4 weeks compared with baseline. The plaque and salivary levels of oral Streptococcus of experimental and vehicle control group differed statistically from each other after 4 weeks, with the strongest reduction in the experimental group and there was statistically difference between treatment control and vehicle control or experimental groups at each time interval. No evidence of deleterious effects to the oral tissues was observed. Daily use of an alum-containing mouthrinse was safe and produced significant reduction effect on plaque and salivary levels of oral Streptococcus and can be used in children for the preventive dentistry.

Adolescent↗
PubMed1997

A model of hypoxia-induced necrotizing enterocolitis: the role of distension.

BACKGROUND/PURPOSE: This study was performed to investigate additional effects of intestinal distension in the damage to the gut caused by hypoxia-reperfusion. METHODS: Five groups each consisting of ten 1-day-old Wistar albino rat pups were studied; Group 1, hypoxia-reoxygenation; Group 2, hypoxia-reoxygenation and distension; Group 3, distension and hypoxia-reoxygenation; Group 4, distension; and Group 5, control. Hypoxia was induced by placing the rat pups in a 100% carbon dioxide chamber for 5 minutes. After the hypoxia, the pups were exposed to 100% oxygen for reoxygenation for 5 minutes. The intestinal distension was carried out with a fine 21-gauge SILASTIC cannula via rectal route. The rats were killed on the third day, and all the intestine were harvested from duodenum to sigmoid colon. Malondialdehyde (MDA) levels were determined as an index of lipid peroxidation related to free radical reaction in the intestine. The histopathologic investigation was carried out by light microscopy in a blinded fashion. RESULTS: The MDA levels of Group 3 animals were significantly higher than those in Group 1, 4, and the control group (P < .05). The MDA level of Group 2 did not differ significantly from that of the Group 3 (P > .05). All MDA levels of the study groups also were significantly higher than the control group (P < .05). CONCLUSION: The results demonstrated that intestinal distension increased the damaging effects of hypoxia-reoxygenation in the gut.

3,4-Methylenedioxyamphetamine↗
PubMed1997

Role of interleukin 8 in the pathogenesis of proliferative vitreoretinopathy.

We investigated the role of interleukin 8 (IL-8) in the pathogenesis of proliferative vitreoretinopathy (PVR). The IL-8 level in the vitreous and the blood of 20 patients with PVR was measured by a specific enzyme-linked immunoassay method. Vitreous from cadaver eyes (n = 20) was used as the control. The IL-8 level in the vitreous was between 31.3 and 65 pg/ml in 40% of eyes with PVR. IL-8 was detected neither in the blood of the patients with PVR nor in the vitreous from cadaver eyes. IL-8 levels in the vitreous did not correlate with either the grade of PVR or the duration of symptoms. These results suggest that IL-8 may play a role in the pathogenesis of PVR.

Adult↗
PubMed1997

Aqueous transforming growth factor-beta-I levels in rabbit eyes after excimer laser photoablation.

Transforming growth factor beta (TGF-beta) plays an important role in anterior segment wound healing, by controlling the cell proliferation and differentiation, angiogenesis, extracellular matrix composition and mediating the immunosuppressive properties of the aqueous humor. The present study was undertaken to clarify the possible changes of aqueous humor TGF-betaI levels after excimer laser photoablation. Twenty-eight New Zealand rabbits were divided into four groups of 7 rabbits each. Group 1 served as control, the central 7 mm of corneal epithelium was removed in groups 2, 3 and 4. We performed 50-microm corneal photoablation in group 3, and 100-microm ablation in group 4. After 48 h we measured the TGF-betaI levels of the aqueous humor by ELISA method. The mean TGF-betaI value of the aqueous humor was found to be 162.94+/-13.73 pg/ml in the control group. Mechanical deepithelialization did not change the TGF-betaI levels of the aqueous humor (p > 0.05). There was no significant difference between the 50-microm photoablated group and the controls (p > 0.05), but the TGF-betaI levels of the 100-microm photoablated group were found to be significantly higher than those of both the control group and 50-microm photoablated group (p < 0.05). Many factors and cytokines may induce corneal haze and myopic regression after excimer laser photoablation; our study demonstrated that TGF-betaI is one of these factors and there is a positive correlation between the depth of corneal photoablation and aqueous TGF-betaI concentrations.

Animals↗