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Biomedical subjects

I Ayan

Publications and source records attributed to I Ayan.

At least 19 recordsLinked to original sources
PubMed2001

Randomized comparison of cefepime versus ceftazidime monotherapy for fever and neutropenia in children with solid tumors.

BACKGROUND: With the availability of new broad-spectrum antibiotics, initial therapy with a single agent has become an alternative to classic combinations, especially beta-lactam antibiotics plus aminoglycosides, in the management of febrile neutropenic cancer patients. PROCEDURE: Since January 1994, monotherapy has been used for empiric initial treatment at our center. The aim of this prospective randomized study is to compare the efficacy of cefepime (CFP), a new fourth-generation cephalosporin, and ceftazidime (CFZ) as empirical monotherapy of febrile neutropenic patients with solid tumors. From January 1998 to November 1998, 63 episodes of fever and neutropenia occurring in 33 children with solid tumors including lymphomas, were randomized to receive treatment with either CFP or CFZ. The patients were analyzed for leukocyte count and absolute neutrophil count (ANC) at entry, days in fever, neutropenia and hospitalization, and side effects of drugs. Success with or without modifications of the initial antibiotic was defined as survival through neutropenia; failure was death due to infection. RESULTS: In our study group, with a median age of 7 [(1/12)-14] years, CFP was administered in 32, and CFZ in 31 episodes. An infection was documented microbiologically in eight episodes (25%) in the CFP arm and in nine episodes (29%) in the CFZ arm. The success rate with initial empiric monotherapy was 62.5% in the CFP arm and 61.3% in the CFZ arm respectively (P > 0.05). The total success rate (success with or without modification) was 100% in both arms. No major adverse effects were observed in either groups. CONCLUSION: CFP is as effective and safe as CFZ for the empirical treatment of febrile episodes in neutropenic patients with solid tumors.

Adolescent↗
PubMed2000

Seroprevalence of hepatitis B, hepatitis C, and human immunodeficiency virus infections in children with cancer at diagnosis and following therapy in Turkey.

BACKGROUND: Children with cancer receiving intensive chemotherapy require multiple transfusions and are at increased risk for blood transmittable diseases such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections. PROCEDURE: Sera from 50 children (24 female, 26 male) admitted between January, 1994, and December, 1995, with solid tumors receiving intensive chemotherapy and multiple transfusions were investigated for HBsAg, anti-HBs, anti-HBc, anti-HCV, and anti-HIV by ELISA at diagnosis and at the end of therapy. RESULTS: HBsAg, HBV, HCV, and HIV seropositivities were 0%, 4%, 2% and 0% at diagnosis and 10%, 20%, 14% and 0% at the end of therapy, respectively. CONCLUSIONS: The high seroprevalence of HCV may be due to the lack of anti-HCV screening of blood products in the blood banks during the study period. Although the HBV seroprevalance of 20% found in this study is much lower than the value of 56% found in a previous study conducted during 1986-1989 in a similar patient population and a similar setting, it is still high. Children infected with HBV during immunosuppressive therapy are at greater risk of becoming chronic carriers and precautions must be taken for immunization of these children.

Adolescent↗
PubMed2000

Non-resective management of pineoblastoma.

The results of a non-resective treatment approach for pineoblastoma comprising stereotactic biopsy, cerebrospinal fluid diversion, and fractionated radiotherapy in six patients over a period of six years are presented. There were three male and three female patients, with a median age at diagnosis of 20 years. Magnetic resonance imaging of the spine, ventricular cerebrospinal fluid cytology, and tumour markers in cerebrospinal fluid were negative. Tumour response to initial radiotherapy was complete in three patients and partial in three patients. Recurrences were treated with interstitial irradiation with iodine-125 seeds in four instances, repeat radiotherapy when time elapsed was more than five years in one instance, with surgical resection in two instances, and chemotherapy in two instances. The diagnostic and therapeutic effectiveness of this management strategy is assessed. There were no complications related to surgical procedures. The median follow-up time was 48 months (range 14-70 months). Five patients were alive at 14, 45, 51, 57, and 70 months of follow-up. One patient died of disease at 28 months following diagnosis. The overall survival rate was 80 % +/- 17.89 % at 28 months. The results of this study suggest that this non-resective treatment approach is acceptable as an initial treatment alternative to radical surgical resection of pineoblastomas.

Adolescent↗
PubMed2000

P53 overexpression in normal oral mucosa of heavy smokers.

The observation that p53 alterations are early events in the tumorigenesis of head and neck cancer and the association with cigarette smoking have prompted us to search for p53 overexpression in the oral mucosa of heavy smokers who have no overt precancerous or cancerous lesions. Formalin-fixed paraffin embedded tissue sections, obtained from oral mucosa of 30 otherwise healthy heavy smokers, were evaluated for tobacco related changes, and immunostained with a mouse monoclonal antibody p53-DO7 for p53 immunoreactivity. Histopathological evaluation revealed hyperplastic changes in twenty eight samples (93%), eight of which also demonstrated dysplastic changes. Positive immunoreaction for p53 was detected in six (20%) of the tissue samples. The study provided significant information about the frequency of hyperplasia, dysplasia, and p53 overexpression in individuals who were heavy smokers. It is suggested, also, that chemoprevention might have some impact in this particular group of individuals.

Adult↗
PubMed1998

Extracranial neuroblastomas and neurological complications.

Between October 1989 and March 1997, 25 pediatric inpatients were treated for primary extracranial neuroblastoma (NB; n=20) or ganglioneuroblastoma (GNB; n=5) at the University of Istanbul, Institute of Pediatric Oncology, and these children were the subjects of this retrospective study. Seventeen (68%) of these patients experienced 19 neurological complications during the course of their disease. Fourteen had nervous system metastases or invasion. Nonmetastatic complications, including CNS infections (n=3) and new onset of seizures (n=2) secondary to metabolic encephalopathy were seen in 5 cases. By the time of the final analysis of the results, 8 of the 17 patients with neurological complications had died, 7 had either been lost to follow-up (n=4) or were in the terminal stage of their disease (n=3), and 2 were in remission. Both of the patients who were in remission had dumbbell neuroblastoma (DNB), and 1 of them, with congenital DNB, also had neurological sequelae, characterized by paraplegia and neurogenic bladder. Neurological complications occurred in 68% of NB and GNB cases. Metastatic complications were more common than nonmetastatic complications and had a poor prognosis. Neurological complications were the primary cause of mortality in this study, mortality being related to neurological complications in 63% of cases, and the final outcome was worse than expected. However, regardless of any differences in social, economic and geographic factors and different treatment protocols for NB in different pediatric oncology institutions, neurological complication rates in pediatric NB are similar in all.

Adolescent↗
PubMed1998

Prognostic value of proliferating cell nuclear antigen immunostaining in pediatric rhabdomyosarcomas.

BACKGROUND: The levels of proliferating cell nuclear antigen (PCNA) are almost negligible in long-term quiescent cells and increase dramatically during the cell cycle. Recently, the monoclonal antibodies to PCNA have been used to demonstrate the proliferative component of paraffin-embedded tumor tissues. It has been shown to be available as a simple histological marker of proliferative activity and the PCNA labeling index has been correlated with the prognosis of several malignant neoplasms. METHODS: Formalin fixed, paraffin embedded tissue specimens of 29 primary pediatric rhabdomyosarcomas were immunostained by using an anti-PCNA monoclonal antibody (DAKO PCNA PC10). The relationship between the PCNA index and prognosis, clinicopathological features and survival were assessed retrospectively. RESULTS: The mean PCNA index for the whole series was 54%. There was no correlation between PCNA index and any of the clinicopathological characteristics. However, patients having tumors with a high (> 54%) PCNA index demonstrated significantly lower survival rates than tumors with a low (< 54%) PCNA index (P = 0.01). Moreover, there were significantly more patients with relapse or progressive disease in the high PCNA index group (P = 0.005). CONCLUSION: The PCNA labeling index can be a useful prognostic factor and a good indicator of recurrence and/or survival in patients with rhabdomyosarcoma.

Adolescent↗
PubMed1998

Germline mutations of the p53 gene in children with malignant solid tumors.

Although somatic mutations of p53 are the most common genetic changes observed to date, the frequency of germline p53 mutations is found to be very low in sporadic malignant tumors. It has been postulated that de novo germline p53 mutations may occur in a substantial population of patients in pediatric age group, who die of their disease and do not propagate the mutation. To determine the frequency and type of p53 germline mutations in pediatric patients, we screened 65 children who were consecutively admitted with primary malignant solid tumors.

Child↗
PubMed1997

Microscopic local leptomeningeal invasion at diagnosis of medulloblastoma.

PURPOSE: To document the incidence and outcome of patients with microscopic local leptomeningeal invasion at presentation, children with medulloblastoma were reviewed. METHODS AND MATERIALS: Nineteen patients (1-12 years of age), who had surgical resection (14 total, 5 subtotal) and were diagnosed as medulloblastoma, were evaluated for disease extent by pre- and postoperative computerized tomography/magnetic resonance imaging, histopathologic evaluation of leptomeninges adjacent to the resected tumor tissue, myelography/magnetic resonance of the entire spine, and analysis of cerebrospinal fluid cytology. Patients were also reviewed for disease outcome. RESULTS: Staging revealed one T2, nine T3a, eight T3b, and one T4 disease. There were 10 M0, 2 M1, 2 M2, 2 M3, and 3 Mx patients according to Chang's classification. Ten out of 19 patients (52.6%) demonstrated microscopic local leptomeningeal invasion. When only the 10 patients with M0 disease were considered, three out of five patients with microscopic local leptomeningeal invasion was found to have one or more relapses. The five other M0 patients without microscopic local invasion were in complete remission at the time of analysis. CONCLUSION: The incidence of microscopic local leptomeningeal invasion in patients with medulloblastoma is high. Whereas the impact on survival remains to be determined in larger series, data suggests prognostic role for isolated microscopic local leptomeningeal invasion, thus validity for inclusion in the future staging system.

Cerebellar Neoplasms↗
PubMed1997

Hypertrophic osteoarthropathy and intrathoracic Hodgkin disease of childhood.

BACKGROUND: Hypertrophic osteoarthropathy (HOA), well known in adults, is rarely encountered in children. The clinical features include clubbing of the fingers and toes, arthritis, and painful periosteal new bone formation of the tubular bones. The association of malignant disorders with HOA is more common in adults than in children. CASE: In this paper, a 12-year-old boy with intrathoracic Hodgkin disease and HOA is presented and four other children with HOA and Hodgkin disease in the literature reviewed. DISCUSSION: The presence of HOA has been thought to be a bad prognostic sign, but complete remission of Hodgkin disease and regression of clinical signs and symptoms of HOA were attained in our patient after chemotherapy and radiotherapy, and continue during 9 months post-therapy follow-up. CONCLUSIONS: HOA accompanying a malignant tumor in children is very rare. Only 5 cases have been associated with Hodgkin disease, including the present boy. It is important that patients with symptoms of HOA and an intrathoracic mass be examined carefully to rule out a malignancy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Renal dysfunctions secondary to ifosfamide treatment in children.

With the increasing use of ifosfamide in pediatric tumors, nephrotoxicity became the point of interest since it may cause chronic morbidity. In this study, the renal glomerular and tubular functions of 25 cases with solid tumors aged between 2-17 years (median 9) who were treated with ifosfamide, were investigated. For this purpose, routine blood urea, creatinine, calcium, phosphorus, electrolytes, urinary creatinine, phosphorus, glucose, protein and urinary retinol binding protein as well as microglobulin were evaluated. Except for two patients who had hypophosphatemia, phosphaturia, and proteinuria, all the cases had normal blood biochemistry, creatinine clearance, tubular phosphate reabsorption; and none had proteinuria, hematuria, or glycosuria. In spite of these findings, urine beta 2 microglobulin and retinol binding protein were found to be high in 11 patients and this elevation persisted during the following one year in 8 cases whose treatments were stopped and their levels increased in three patients who continued to receive fosfamide therapy. In correlation with the increasing cumulative dose of ifosfamide (32-126 g/m2), urinary retinol binding protein or beta 2 microglobulin of patients who are treated with ifosfamide may predict the existence of renal toxicity even if other routine renal function tests are normal. Thus, the periodic evaluation of urinary beta 2 microglobulin and retinol binding protein in patients receiving chemotherapy containing ifosfamide is recommended.

Adolescent↗
PubMed1996

Clinical and cytogenetic studies of two cases of Klinefelter syndrome with hereditary retinoblastoma and rhabdomyosarcoma.

Two children with Klinefelter syndrome (KS), one associated with bilateral hereditary retinoblastoma (RB) and the other with rhabdomyosarcoma (RMS) are reported. Both were boys and chromosomally mosaic for KS. The hereditary retinoblastoma case yielded 46,XY,del(13)(q12q14.2)/47, XXY(c),del(13)(q12q14.2) in PHA-stimulated lymphocytes. The rhabdomyosarcoma case yielded 46,XY/ 47,XXY(c) in peripheral blood cells whereas tumor revealed trisomy 8, trisomy 7, and t(7;13)(q33;q32) in addition to 46,XY/47,XXyc mosaicism.

Child, Preschool↗
PubMed1996

Nasopharyngeal carcinoma in children: retrospective review of 50 patients.

PURPOSE: To report a retrospective analysis of epidemiologic, clinical, and therapeutic aspects of 50 children with newly diagnosed nasopharyngeal carcinoma who were treated in a single institution over a period of 18 years. METHODS AND MATERIALS: Thirty-two male and 18 female children ranging from 5 to 16 years, accounted for 7.2% of all nasopharyngeal carcinoma cases and 52% of childhood nasopharyngeal malignancies. Histopathology was World Health Organization Type 3 carcinoma in 45, World Health Organization Type 2 in 4, and World Health Organization Type 1 in one patient. Two of the patients had missing information for staging and treatment evaluation. Disease extent was T1 (n = 4), T2 (n = 9), T3 (n = 21), and T4 (n = 14); N0 (n = 1), N1 (n = 6), N2 (n = 12), and N3 (n = 29). Six patients had base of skull invasion, two had cranial nerve palsies, and six had both. One patient had M1 disease on admission. Twenty-three patients were treated with irradiation only. Thirteen patients received adjuvant, and 12 had neoadjuvant chemotherapy in addition to radiotherapy. Patients received 50-72 Gy to the primary tumor and involved nodes, and 45-50 Gy to uninvolved regions. Chemotherapy consisted of combinations including cisplatin, bleomycin, epirubicin, 5-fluoroucil, and cyclophosphamide. RESULTS: Thirty-eight (79%) patients attained locoregional control. Overall, 22 patients are alive without relapse 6-195 months from diagnosis. Thirteen patients had 21 relapses, at local and/or regional sites (43%), distant sites (48%), or both (9%). The median time for first relapse was 8 months. Overall, the 5-and 10-year survival rates were 52 and 52%, respectively, and the failure-free survival rates were both 53%. The results of three distinct treatments given in subsequent time periods were not statistically different. Three second malignancies occurred 33-156 months following nasopharyngeal carcinoma diagnosis. CONCLUSION: In the current series, nasopharyngeal carcinoma patients under the age of 16 accounted for 7.2% of all nasopharyngeal carcinoma cases. Whereas the impact of chemotherapy on long-term survival remains to be determined by randomized studies, the results suggest that more effective treatment regimens and long-term follow-up are necessary for children with nasopharyngeal carcinoma.

Adolescent↗
PubMed1996

Primary spinal column sarcomas.

Five cases of primary spinal column sarcomas are presented. Sarcomas primarily originating from paravertebral soft tissues were excluded. Patients' age ranged from 1 to 14 years (mean 8.4 years). The male:female ration was 2:3. Two patients had Ewing's sarcoma (ES) originating from L5-S1 and L4-5 pedicles, respectively; two patients had mesenchymal chondrosarcoma (MCS) originating from L1-2 pedicles and L5 body, respectively; and one patient had osteogenic sarcoma (OS) of C4 body. All patients clinically presented with pain and progressive weakness of the extremities. The time that elapsed between the onset of symptoms and diagnoses ranged from one to five months. All cases were treated with chemotherapy, radiotherapy and subtotal tumour resection with spinal canal decompression. Two cases received posterior spinal fusion operations. Three patients were alive 10 to 98 months following diagnosis. Only the case with ES of L5-S1 pedicles was in complete remission and off therapy at the 98th postoperative month. The two MCS cases were in partial remission, and were receiving chemotherapy at the time of analysis. These tumours caused similar clinical findings and prognoses, and required combined treatment, which consisted of surgery, radiotherapy and chemotherapy; histologically three different types of malignant tumours are presented in the same category. We preferred surgical decompression and stabilization procedures especially for neurologically symptomatic patients, even if they had extensive tumours with high grades. By spinal canal decompression and stabilisation, we did not intend to cure the disease; however, we intended to provide neurological improvement, spinal stabilisation, improved quality of life, early mobilisation of the patient, and cytoreduction by means of surgical tumour ablation, which could render the chemotherapy more effective.

Adolescent↗
PubMed1995

Immunologic status in children with brain tumors and the effect of therapy.

The cellular and humoral immunological parameters (leucocyte, granulocyte, lymphocyte, total T, T4, T8 lymphocyte counts, lymphoproliferative response to PHA [LP-PHA], natural killer cell activity [NKCA], IgG, IgM and IgA levels) of 20 pediatric brain tumor patients were investigated before and after chemo-(CT) and radiotherapy (RT) administered according to the UIOI-PBT-91 protocol. The T4 and T8 cell percentages and the LP-PHA values before therapy were found to be significantly diminished in comparison to values obtained from 12 healthy children (p < 0.05). In patients receiving postoperative CT, all cellular immunity parameters except T8 cell number and NKCA; IgG and IgA levels were significantly decreased after two courses of CT (p < 0.05). In 7 patients given postoperative RT, a depression in all cellular immunity parameters was observed (p < 0.05). In 6 patients treated with 2 courses of postoperative CT followed by RT administered concomitantly with low dose CDDP, there was a decrease in all cellular and humoral immunity parameters, which was not found to be significant. In 5/18 patients infectious episodes in mild to moderate severity were observed, none causing mortality. It was concluded that the UIOI-PBT-91 protocol caused cellular immunosuppression both after CT and after RT and some humoral immunosuppression after CT, but was found to be tolerable in regard to acute immunological side effects.

Adolescent↗
PubMed1995

Evaluation of response to postradiation eight in one chemotherapy in childhood brain tumors.

Ten children, 3 to 15 years of age with high risk primary brain tumors were treated with postradiation 'eight in one' chemotherapy; vincristine, lomustine, procarbazine, hydroxyurea, cisplatin, cytosine arabinoside, cyclophosphamide and methylprednisolone. The tumors comprised of three medulloblastomas, two primitive neuroectodermal tumors, one ependymoblastoma and four anaplastic ependymomas. Treatment involved surgery (two total resection, six subtotal and two biopsy only) followed by conventional radiotherapy (primary tumor: 50-54 Gy, whole brain: 30-45 Gy, and spinal axis: 25-36 Gy). Objective tumor response with radiotherapy was achieved in 7 of 9 patients (78%) (6/8 patients with residual tumor and one patient with complete resection but positive cerebrospinal fluid cytology). Complete response was attained in 4 of 9 patients (44%). 'Eight in one' chemotherapy was initiated four weeks after radiation and repeated at 4 weekly intervals for 5-8 courses. Postradiation 'eight in one' failed to show any additional effect on tumor responses. Median survival was 34 months (range 9-48 months) with five of ten patients alive: four in complete and one in partial remission. All the five survivors were among the patients who had achieved response to initial treatment. This result suggested that degree of response to initial treatment might determine subsequent outcome and thus the choice of modality for initial therapy might be important.

Adolescent↗