Coupling of remote sensing, field campaign, and mechanistic and empirical modeling to monitor spatiotemporal carbon dynamics of a Mediterranean watershed in a changing regional climate.

The aim of this study was to simulate impacts of regional climate change in the 2070s on carbon (C) cycle of a Mediterranean watershed combining field measurements, Envisat MERIS and IKONOS data, and the Carnegie Ames Stanford Approach model. Simulation results indicated that the present total C sink status (1.36 Mt C year(-1)) of Mediterranean evergreen needleleaf forest, grassland and cropland ecosystems is expected to weaken by 7.6% in response to the climate change in the 2070s (Mt=10(12) g). This decreasing trend was mirrored in soil respiration (R H), aboveground and belowground net primary production (NPP), NEP, and net biome production (NBP). The decrease in NEP in the 2070s was the highest (21.9%) for mixed forest where the smallest present C sink of 0.03 Mt C year(-1) was estimated. The average present net ecosystem production (NEP) values were estimated at 110±15, 75±19, and 41±25 g C m(-2) years(-1) in forest, grassland, and cropland, respectively, with a watershed-scale mean of 95±30 g C m(-2) years(-1). The largest present C sink was in grassland, with a total C pool of 0.55 Mt C year(-1), through its greater spatial extent.

The efficiency of different chemoradiotherapy regimens in patients with paediatric nasopharynx cancer: review of 46 cases.

The purpose of this study was to evaluate the role of combined modality treatment in patients with paediatric nasopharynx cancer (NPC). Forty-six patients with paediatric NPC were retrospectively analysed. Forty-four of 46 patients received combined modality treatment. Five-year overall survival and progression-free survivals were 70% and 72% for the whole group, and only three of 46 patients had loco-regional relapse. Complete remission was obtained in 18 of 45 patients (40%), and the overall survival (94% vs. 62% and 19%, p = 0.0009) and disease-free survivals (93% vs. 70% and 16%, p = 0.0002) were significantly better in complete responders when compared with the patients who had partial response or stable disease. The 5-year overall survival and disease-free survivals of the patients who received neoadjuvant chemotherapy (CT) and radiotherapy (RT) followed by CT were superior to the other groups (77% and 80%, respectively). The number of total CT cycles (p = 0.0001), nodal stage (p = 0.05) and treatment response (p = 0.0009) were significant prognostic factors for overall survival. The treatment type (p = 0.02), the number of total CT cycles (p = 0.0006), nodal stage (p = 0.05) and treatment response (p = 0.0002) were found as significant prognostic factors for disease-free survival. The survival of patients receiving six or more CT cycles was also significantly better than that of patients receiving less than six cycles (p = 0.0001). In patients with locally advanced paediatric NPC, CT should be added to RT to improve outcome. However, a standard protocol is yet to be identified, and further studies evaluating the addition of interferon or immunotherapy to CT and RT shall be performed.

Coastal flood risk analysis using landsat-7 ETM+ imagery and SRTM DEM: a case study of Izmir, Turkey.

The Intergovernmental Panel on Climate Change (IPCC) reports an acceleration of the global mean sea-level rise (MSLR) in the twentieth century in response to global climate change. If this acceleration remains constant, then some coastal areas are most likely to be inundated by the year 2100. The ability to identify the differential vulnerability of coastlines to future inundation hazards as result of global climate change is necessary for timely actions to be taken. Yildiz et al. (Journal of Mapping, 17, 1-75, 2003) reported that the local MSLR in the city of Izmir rose at a rate of 6.8 +/- 0.9 mm year(-1) between 1984 and 2002. In this study, the spatial distribution of the coastal inundation hazards of Izmir region was determined using not only land-use and land-cover (LULC) types derived from the maximum likelihood classification of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) multi-spectral image set but also the classification of the digital elevation model (DEM) acquired by the shuttle radar topography mission (SRTM). Coastal areas with elevations of 2 and 5 m above mean sea-level vulnerable to inundation were found to cover 2.1 and 3.7% of the study region (6,107 km(2)), respectively. Our findings revealed that Menemen plain along Gediz river, and the settlements of Karsiyaka, Alacati, Aliaga, Candarli and Selcuk are at high risk in order of decreasing vulnerability to permanent and episodic inundation by 2100 under the high MSLR scenarios of 20 to 50 mm year(-1).

Environmental monitoring of land-use and land-cover changes in a Mediterranean region of Turkey.

Unprecedented rates of human-induced changes in land use and land cover (LULC) at local and regional scales lead to alterations of global biogeochemical cycles. Driving forces behind LULC changes mainly include rapid growth rates of population and consumption, lack of valuation of ecological services, poverty, ignorance of biophysical limitations, and use of ecologically incompatible technologies. One of the major ecological tragedies of the commons in a Mediterranean region of Turkey is the loss of Lake Amik at the expense of increasing the area of croplands, which used to provide vital ecosystem goods and services for the region. In this study, we aimed at quantifying the effects of past land-use transitions on soil organic carbon (SOC) pools (0-20 cm) in a Mediterranean region of 3930 km(2), between 1972 and 2000. LULC changes were quantified from a time series of satellite images of Landsat-MSS in 1972, Landsat-5 TM in 1987, and Landsat-7 ETM+ in 2000 using geographic information systems. The study showed that the increase in croplands between 1972 and 1987 took place at the expense of the irreversible losses of Lake Amik and its related wetlands of over 53 km(2). In the period of 1972 to 2000, croplands, settlements, and evergreen forests increased by 174%, 106%, and 14%, respectively. The increase in settlements occurred mostly to the detriment of croplands. Given the average rates of all the land-use transitions, and associated changes in SOC density for the study region of 3930 km(2), total SOC pool was estimated to decrease by 14.1% from 130.1 Mt in 1972 to 111.7 Mt in 2000.

Nasopharyngeal carcinoma in Turkish children: review of 33 cases.

A retrospective and prospective analysis is reported of epidemiological, clinical, and therapeutic aspects of 33 children with nasopharyngeal carcinoma who were treated in a single institution over a period of 10 years. Twenty-three male and 10 female children ranging from 9 to 17 years were referred to our center. Histopathology was WHO type 3 carcinoma in 21, WHO type 2 in 8, WHO type 1 in 1, and unclassified in 3 patients. Disease extent was T2a (n = 15), T2b (n = 2), T3 (n = 11), and T4 (n = 5); N1 (n = 5), N2 (n = 12), and N3a (n = 16). Five patients had base of skull invasion. Four patients had M1 disease on admission. Four patients were treated with irradiation only. Three patients received neoadjuvant, 4 patients received adjuvant, and 22 patients received neoadjuvant + adjuvant 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 of cisplatin, fluorouracil or Adriamycin, vincristine, and cyclophosphamide. Twenty-nine patients (88%) attained locoregional control. Overall, 10 patients died with progressive disease or infectious complications, and 2 patients are still receiving therapy. Three patients are still living with multiple metastases and stable disease. Eight patients were lost to follow-up. Twelve patients are alive without relapse 3 and 63 months from diagnosis. Seven patients had 6 relapses at distant and 1 relapse at local site. The median time for first relapse was 8 months. Overall, the 5-year survival rate was 63% and disease-free survival rate was 53%. Although the locoregional control rate is high, long-term survival rates will be the real test of the impact of chemotherapy. Further studies are needed to confirm the optimal combination of effective chemotherapeutic agents and radiotherapy.

Subcutaneous sacrococcygeal myxopapillary ependymoma.

We report an 8-year-old boy with a primary subcutaneous sacrococcygeal ependymoma, a rare tumor that is thought to arise in embryologic rests. The lesion was completely removed in our patient, who has been followed without recurrence for 20 months. Our experience, together with that of the other 15 cases in the world literature, supports surgical excision as the mainstay of treatment.

Osteoblastoma response to radiotherapy and chemotherapy.

Osteoblastoma is a rare primary bone tumor that is curable by complete excision. There are few data about the effectiveness of chemotherapy or radiotherapy in the treatment of recurrent osteoblastoma. We report a 13-year-old girl wit recurrent osteoblastoma who, after in complete surgical excision, responded to treatment with radiotherapy and later with chemotherapy. Surgery remains the treatment of choice for osteoblastoma. Radiotherapy and chemotherapy either alone or together may be useful in selected patients with recurrent, aggressive tumor or in patients with surgically unresectable disease.

Successful treatment of intracaval and atrial extension of Wilms' tumour by chemotherapy.

A patient presenting with advanced Wilm's tumour was diagnosed as having inferior vena cava involvement with tumour thrombus extending up to the right atrium, and was treated with preoperative chemotherapy (vincristine, actinocymin D, epirubicin). Atrial and inferior vena cava thrombus disappeared and he underwent a successful nephrectomy.

The seroprevalence of hepatitis B, hepatitis C and human immunodeficiency virus infections in paediatric oncology patients in Turkey.

One hundred and two newly diagnosed children with malignancy followed up at the Pediatric Oncology Department of Ankara Oncology Hospital were investigated for hepatitis B, hepatitis C and human immunodeficiency virus markers. The ages ranged between seven months and 17 years with a median of 10 years; 62 were male. Twenty-four patients had Hodgkin's disease, 11 had non-Hodgkin's lymphoma and 67 patients had other solid tumours. Four patients had positive HBs-Ag, 15 developed immunity against hepatitis B and had anti-HBs antibodies. One patient had a previous infection with positive anti-HBc. Hepatitis C virus antibodies were positive in only one patient. HIV serology was negative in all patients. These results show the high prevalence of hepatitis B virus infection in paediatric oncology patients. In countries where hepatitis B is endemic, strict screening of blood donors, usage of disposable equipment and vaccination of patients is recommended. Although the incidence of hepatitis C and human immunodeficiency virus infections are rising, infection with hepatitis B is still by far the most common.

Carcinoma of the colon in children.

The symptoms, histology, extent and course of disease in 16 adolescents with colorectal carcinoma who were admitted to Hacettepe University Children's Hospital between 1972 and 1990 are presented. Most patients presented with vague abdominal complaints. Twelve of the 16 patients had mucin-producing adenocarcinoma. Extensive disease at diagnosis and unresponsiveness to medical management were determined. Only one patient survived free of disease four years after diagnosis. Nine of the patients died between one day and one year following the initial surgery. The remaining six patients were very ill when they were discharged from the hospital, after which time no information was received concerning them.

Nonlymphoid gastrointestinal malignancies in Turkish children.

Nonlymphoid gastrointestinal malignancies are not frequently encountered malignant tumors of childhood. From 1972 to 1994, at Hacettepe University Children's Hospital, there were 6,774 malignant tumors encountered in patients from birth to age 17. Thirty-five of them (0.5%) originated from the gastrointestinal tract. There were five carcinoid tumors, four pancreas tumors (two were solid-cystic tumors), four APUD-omas, three leiomyosarcomas, one mesothelioma, two carcinomas of the stomach and duodenum, and 16 colon and rectum carcinomas (12 were mucin-producing). These rare tumors are discussed according to the characteristics of the patients, therapy modalities applied, and outcome of the patients.

Prevention of emesis by tropisetron in children receiving combined chemotherapy with cisplatin.

We evaluated the antiemetic efficacy of tropisetron, a 5-HT3 receptor antagonist, during its use in 15 children with malignant disease who received cisplatin (CDDP) either alone (1/15) or in combination (14/15) with other cytostatic drugs. Tropisetron was given to 15 children (8 boys and 7 girls, ranging from 6 months to 17 years of age) with miscellaneous neoplasms. Generally, tropisetron (5 mg/m2/day, maximum 5 mg/day) was administered intravenously the first day of CDDP-based chemotherapy and orally for 4 subsequent days of chemotherapy. The dose of tropisetron was reduced to 0.2 mg/kg/day in children less than 1 year of age and/or those weighing less than 10 kg. Vomiting and nausea were controlled completely in 8 of 15 (53.3%) children on day 1 with a single intravenous infusion of tropisetron. Partial control was observed in 40% of patients on day 1. Complete control of delayed nausea and vomiting ranged between 40% and 80% in patients over days 2 to 5. The results obtained during administration of tropisetron confirm that it is a valid, safe, and manageable antiemetic for the treatment of malignant disease in pediatric patients.

Methotrexate-induced leukoencephalopathy. A case report.

A six-year-old girl with non-Hodgkin's lymphoma who was treated with both intravenous (IV) and intrathecal (IT) methotrexate and developed brain damage secondary to the cytostatic drug is described. This patient displayed hypertension, hypothermia/hyperthermia, lethargy, deterioration and coma as clinical findings, and bilateral, focal white matter hyperintensities in the occipital lobes were seen in her magnetic resonance imaging (MRI). Treatment-related leukoencephalopathy is one such adverse effect of IT methotrexate administration on the central nervous system and usually appears in a generalized form.

Immune thrombocytopenic purpura in a child with Hodgkin's disease.

The occurrence of immune thrombocytopenic purpura (ITP) in Hodgkin's disease is uncommon. This report describes a patient who developed ITP twice before splenectomy, and for the third time several years later, preceding an abdominal relapse of the disease. We suggest that patients with a history of Hodgkin's disease undergo diligent searches for active disease when ITP is diagnosed. ITP may be the only manifestation of active disease and may precede histologic documentation of Hodgkin's disease by months or years.

Skin involvement in children with non-Hodgkin's lymphoma.

This study was performed to present our clinical experience with patients with cutaneous malignant lymphoma. Eight of 856 (1%) patients admitted to Hacettepe University Pediatric Oncology Department were diagnosed with skin involvement of non-Hodgkin's lymphoma between November 1971 and December 1992. At the time of diagnosis, the mean patient age was 9.5 years (range 4-15). The male-to-female ratio was 1.7:1. Three of the eight cases had primary cutaneous lymphoma, four had non-Hodgkin's lymphoma (NHL) with skin involvement and one case cutaneous lymphoma as a part of advanced stage NHL. According to Murphy's clinical classification, three cases with primary cutaneous lymphoma were in stage I E, two of the remaining five patients were in stage III and three patients with organ involvement were in stage IV. All eight patients' skin lesions were 6 to 10 cm in diameter, hyperemic, firm and nodular. The skin of the head and neck region, especially the right cheek, was the most involved area. In primary cutaneous lymphomas, the duration between involvement and diagnosis was two to six months. All but two patients received the LSA2 L2 protocol. The other two were treated with the COP protocol and a modified COMP protocol. Three patients in stage I E are now living disease-free. One of the two patients in stage III is disease-free, and the other is in the fifth month of therapy with very advanced disease and is lost to follow-up. Among the three patients in stage IV, one was living disease-free for 38 months after diagnosis, while the other two patients are still under therapy without disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B vaccination in children with cancer.

Between September 1991 and April 1993 the hepatitis B vaccination with recombinant hepatitis B vaccine was administered in 41 cancer patients following first diagnosis. All patients were under 16 year of age, with negative hepatitis B virus (HBV) serology and normal hepatic function. They received 40 micrograms of vaccine by injection into the deltoid muscle at 0, 1, and 2, months, with a fourth dose planned at the 4th month for nonresponders. At 1 year a booster dose was given. All the patients began vaccination within 1 month following diagnosis, and periodic serologic follow-up was performed immediately after each vaccination and also in the 6th, 9th, and 12th months after vaccination. Patients with production of anti-HBs at a titer equal to or greater than 10 mIU/L were considered seropositive. The seroconversion rates were 12.4%, 21.9%, 41.0%, and 48.7% after the first, second, third, and fourth monthly doses, respectively. Seroconversion rates were 56.0% at 6 months, 67.5% at 9 months, and 70.5% at 12 months. Geometric mean antibody titers were 212 and 373 mI U/L at 9 and 12 months, respectively. No serious side effects were observed. HBV vaccination is recommended for pediatric cancer patients.