PubMed Health⌕ Search

Biomedical subjects

N Olgun

Publications and source records attributed to N Olgun.

At least 19 recordsLinked to original sources
PubMed2001

A rare tumor of craniofacial bones in children: a pediatric chondroblastic osteosarcoma case with diagnostic and therapeutic problems.

Osteosarcoma of the cranial facial region is uncommon and only rarely involves the ethmoid or sphenoid bones. The authors report on an unusual case of a 17-year-old male presenting with chondroblastic osteosarcoma of the maxillary, ethmoid, and sphenoid sinuses who remains well and disease-free at 46 months. He was treated with anterior craniofacial resection followed by postoperative radiotherapy to the sight of the primary tumor. He did not receive chemotherapy because of emerging hepatitis-B infection and vasculitis. The literature on extragnathic craniofacial osteosarcomas is reviewed with particular emphasis on treatment options of this rare tumor.

Adolescent↗
PubMed1998

Platelet activation during the early neonatal period.

The first week of life is a time when hereditary or more frequently acquired factors lead to some important differences in the hemostatic mechanism of the newborn. It has been well known that ill neonates are prone to both hemorrhage and thrombosis. The aim of this study was to answer the question of whether there is a difference in platelet activation in healthy neonates during the first days of life that may contribute to both hemorrhage and thrombosis in the presence of additional pathologic insults. Platelet activation was determined with flow cytometry using monoclonal antibodies in 63 healthy children (29 neonates, 17 infants, and 17 older children). There was no significant difference in platelet activation among these three age groups (p > 0.05). In addition, platelet activation did not show any significant relationship to age, sex, mode of delivery, or blood bilirubin concentration (p > 0.05). It has been previously reported that platelet activation occurs at the time of birth. We could not find any evidence that healthy newborns during the first 3 days of life exhibit increased platelet activation. Further studies on platelet activation in ill neonates will help to clarify whether platelet activation plays a role in the pathogenesis of thrombotic and/or hemorrhagic disorders.

Antibodies, Monoclonal↗
PubMed1997

Posterior fossa pseudotumour due to viral encephalitis in a child.

A 14-year-old boy had a 1-month history of diplopia (due to a VI nerve palsy), motor ataxia and dizziness. Brain MRI showed a 1.5-cm mass posterior to the pons. Histopathological examination of a biopsy specimen showed the lesion to be of viral origin. After 3 months, the ataxia and dizziness had resolved and the MRI findings returned to normal. By 5 months the abducens paralysis had also resolved. Viral encephalitis should be considered in the differential diagnosis of posterior fossa tumours.

Adolescent↗
PubMed1997

Platelet activation in congenital heart diseases.

The research presented here investigated platelet activation in cyanotic and acyanotic congenital heart diseases (CHD). Children with cyanotic CHD are prone to both thrombosis and hemorrhage. However, patients with acyanotic CHD may also have a mild bleeding disorder. The platelet activation in CHD was investigated in support of a hypothesis that platelet activation may play a role in the hemostatic abnormalities reported in these patients. Platelet activation was determined by using flow cytometry with anti-CD62 monoclonal antibody (mAb), which has been shown to be a specific marker of platelet activation. Thirteen children with cyanotic CHD, 33 children with acyanotic CHD and 17 healthy children serving as controls were studied. Platelet activation was significantly higher in the cyanotic group and also in the acyanotic group compared with the healthy children (P = 0.0000 and P = 0.019, respectively). In the cyanotic group, platelet activation showed a direct correlation with arterial O2 saturation (SaO2) (P = 0.014). There was no correlation between platelet activation and erythrocyte related parameters in either group. Platelet activation occurs in CHD, particularly in patients with cyanotic CHD (even in patients with no evidence of clinical thrombosis) and it may play a role in the pathogenesis of thrombotic disorders seen in these patients.

Child, Preschool↗
PubMed1995

Atypical hemolytic uremic syndrome.

The pathogenesis of atypical uremic syndrome (HUS), which is rarely encountered in childhood, is poorly understood and its mortality and morbidity rates are high. A wide variety of therapeutic approaches has been attempted and the literature contains numerous conflicting reports about the results of these approaches. In a case diagnosed as recurrent atypical HUS, pulse methyl prednisolone, fresh frozen plasma infusions and plasma exchange transfusion were used at different stages of the disease with satisfactory response.

Child↗
PubMed1995

Relationship between serum unconjugated bilirubin levels and the autofluorescence of white blood cells in neonatal jaundice.

In this study, using flow cytometry, we investigated the autofluorescence emitted by lymphocytes, monocytes and neutrophils exposed to different unconjugated bilirubin concentrations and investigated the relationship between these parameters. Different unconjugated bilirubin concentrations were prepared from a newborn serum with an unconjugated bilirubin concentration of 800 m mumol/l. The same concentrations of unconjugated bilirubin have been prepared from pure bilirubin. 10 microliters of cord blood were incubated at room temperature for 15 min with 90-microliter solutions with different bilirubin concentrations prepared from both serum and pure bilirubin. After incubation, cells were washed three times with PBS, erythrocytes were lysed by lysing buffer and run through flow cytometry immediately. Autofluorescence was measured by recording mean fluorescence channels for lymphocytes, monocytes and neutrophils. There was a good correlation between serum concentrations of unconjugated bilirubin that cells were exposed to and the autofluorescence intensity of neutrophils (r = 0.904, p < 0.005), monocytes (r = 0.759, p < 0.05) and lymphocytes (r = 0.766, p < 0.01). Results obtained with pure bilirubin were also similar. Autofluorescence emitted by lymphocytes was lower than that of monocytes (p < 0.01) or neutrophils (p < 0.0005).

Bilirubin↗
PubMed1993

Nutrition, immunity and infections: T lymphocyte subpopulations in protein--energy malnutrition.

Protein energy malnutrition (PEM) is one of the most frequent causes of secondary immune deficiency states. Alterations either in cellular or humoral immune mechanisms increase the susceptibility to infections in the malnourished organism. Infections aggravate the interrelationship of malnutrition to immune deficiency and infections, resulting in future adverse effects of malnutrition on humoral and cellular immune systems, IgG, IgM, IgA, C3, and T lymphocyte subpopulations were identified in 29 patients with PEM and 15 healthy infants serving as the control group, ranging between 3 and 24 months of age. Patients with PEM demonstrated elevated levels of IgG, IgM and IgA when compared to the control group (P < 0.01, P < 0.01, P < 0.01), C3 levels were significantly lower than the values of the control group (P < 0.01).

Antibodies, Monoclonal↗
PubMed1993

Diffuse erythrodermic cutaneous mastocytosis with bone marrow infiltration.

We report a case of diffuse erythrodermic cutaneous mastocytosis with bone marrow infiltration. An 11-month-old female patient was referred to our hospital for intermittent flushing, fever, intense itching, erythematous rash and bullous lesions. Cutaneous biopsy demonstrated diffuse cutaneous mastocytosis. The bone marrow aspirate revealed mast cell infiltration. Ketotifen treatment was very effective.

Biopsy↗
PubMed1992

Pulmonary blastoma: a rare case of childhood malignancy.

A case of pulmonary blastoma is presented with review of the radiographic, ultrasonographic and CT appearances of this rare malignant tumor of children. Pulmonary blastoma arises from primitive lung mesenchyma and histologically resembles fetal lung. The clinical presentation is usually respiratory distress. The prognosis of the disease is poor even if surgical resection, supplemental chemotherapy and radiation therapy are performed. We present a case of pulmonary blastoma who died two days after surgical resection.

Child, Preschool↗
PubMedDate not supplied

Assessment of clinical impact and predisposing factors for neonatal thrombocytopenia.

Thrombocytopenia is a common hemostatic abnormality in the newborn infant. The early diagnosis of thrombocytopenia and the underlying primary pathology process play an important role in reducing the risk of severe complications and mortality. We performed a 2-year prospective study of 643 neonates admitted to our neonatology unit to determine the frequency, predisposing factors, and clinical impact of thrombocytopenia. Thrombocytopenia developed in 18.2% of the preterm neonates and 0.8% of the term neonates. Prematurity, sepsis, hypoxia, intrauterine growth retardation, and disseminated intravascular coagulation were identified as predisposing factors for thrombocytopenia. The incidence of complications and mortality were higher in thrombocytopenic infants. Especially the prognosis was worse in cases who had mucosal hemorrhage, without a relation with the degree of thrombocytopenia. The thrombocytopenia occurred by day 2 in 43% of the infants, and resolved by day 8 in 61%. The platelet count nadir occurred by day 2. Since thrombocytopenic infants are at greater risk for bleeding, and the thrombocytopenia itself may have contributed to the high mortality, predisposing factors such as prematurity, infections, hypoxia must be eliminated by providing better care, giving adequate hygiene of both mother and the baby during the prenatal, natal, and neonatal period.

Causality↗
PubMedDate not supplied

A case with extraosseous Ewing's sarcoma: a late effect related to bone marrow transplantation for thalassemia or a component of a familial cancer syndrome?

Allogeneic bone marrow transplantation has proved to be a radical form of cure in patients with beta-thalassemia major who have a human leukocyte antigen identical donor. Although malignant neoplasms are serious late complications of bone marrow transplantation, very few reports describing the development of malignant tumors after allografting for thalassemia appeared in the literature. A case is presented here of extraosseous Ewing's sarcoma that developed 8 years after allogeneic bone marrow transplantation performed for beta-thalassemia major. The phenotypic features of the patient's family fulfill the criteria for Li-Fraumeni syndrome. The patient was treated with chemotherapy and radiotherapy and died with recurrent disease. To the authors' knowledge, this is the first case of extraosseous Ewing's sarcoma after bone marrow transplantation for thalassemia. The possible contribution of transplantation procedure and the genetic factors as well as the primary genetic hemoglobinopathy to the development of this malignant tumor are discussed.

Adult↗
PubMedDate not supplied

High-dose oral methylprednisolone therapy in childhood hemangiomas.

The authors report their experience with high-dose oral methylprednisolone therapy (HDMP) in 15 infants with complicated hemangiomas. The starting dose for methylprednisolone was 30 mg/kg/day for 5 days, then the dose was tapered gradually every 5 days to 20, 10, 5, 2.5, and finally to 1 mg/kg/day. Therapy was then stopped and the patients were followed. An initial response was evident in 12 patients. Nine out of 12 responders showed regrowth signs. After regrowth, 4 cases received prednisolone at doses between 1 to 5 mg/kg/day and 3 patients received a second course with HDMP as additional corticosteroid therapy. Overall, 9 out of 15 cases were responders; very good and good responses were obtained in 5, partial response in 4, and therapy failure in 5 cases. One child was not available for evaluation of response. A very rapid initial response was observed in subglottic and periocular hemangiomas. Side effects were not serious and resolved after discontinuation of treatment. Although the number of patients is small in this study, overall response rate with HDMP regimen seems not to be superior to the regimens that use lower doses (5 mg/kg/day), but it provides a high initial response rate and the duration of therapy is short. Therefore, it may be useful for treating hemangiomas that fail to respond with low doses, especially in centers with limited resources where other treatment modalities cannot be used at the moment.

Administration, Oral↗
PubMedDate not supplied

Hyperglycemia and acute parotitis related to L-asparaginase therapy.

In a boy with non-Hodgkin's lymphoma (NHL), two different complications developed concurrently associated with L-asparaginase (L-ASP) therapy. A non-ketotic hyperglycemic state was observed simultaneously with bilateral acute parotitis after the patient was subjected to L-ASP. The hyperglycemia with normal insulin levels and the absence of plasma and urine ketones was controlled with insulin therapy and no residual impairment of glucose tolerance was demonstrated later. Bilateral acute parotitis, which is a rare complication associated with L-ASP, resolved spontaneously within a week after cessation of L-ASP. The rarely observed toxic effects of L-ASP, such as parotitis, should be recognized as promptly as the better-known complications, e.g., hyperglycemia, to avoid the continuation of this antineoplastic agent.

Acute Disease↗