Biomedical subjects

G Bjarnason

Publications and source records attributed to G Bjarnason.

4 recordsLinked to original sources

PubMed2003

It is time for chronotherapy!

The EORTC Chronotherapy Group (CTG) stemmed from the International Organisation for Cancer Chronotherapy(IOCC) in 1996. The IOCC was the first to initiate large scale multicentre international chronotherapy trials, for the purpose of investigating the relevance of chronomodulated or timed administration of cancer therapy based on biological rhythms. Programmable pumps for cytotoxic chronodelivery and actigraph devices to monitor circadian rhythm alterations linked to cancer were also developed. The unique expertise of the IOCC with regard to cancer chronotherapy furthered its development within the EORTC. EORTC offers broad expertise in clinical cancer research and opportunities for scientific recognition, inter-group collaborations and translational research. Over the past 5 years, EORTC CTG has grown from 16 to 48 centres in 12 different countries. It is currently conducting seven multicentre chronotherapy trials, which test the relevance of adapting cancer treatment delivery to circadian rhythms. The group aims at developing multiple collaborations to establish a chronotherapy network involving institutions with expertise ranging from experimental chronobiology to new drug testing, disease-specific management and quality of life or survival issues.

Antineoplastic Agents↗

PubMed2001

[Hirschprung' disease in Iceland 1969-1998.].

INTRODUCTION: Hirschprung s disease (HD) is a congenital disease characterized by the absence of myenteric and submucosal ganglion cells in the distal alimentary tract and results in decreased motility in the affected bowel segment. The purpose of this study was to review the incidence, presentation, treatment and operative results in children with Hirschprung's disease in Iceland. MATERIAL AND METHODS: Thirteen infants with Hirschprung s disease (11 boys and two girls) were treated in Landspítalinn University Hospital between January 1969 and December 1998. The records of these patients were reviewed retrospectively. RESULTS: The incidence of Hirschprung's disease in Iceland is 1/10,000 and 85% of those are boys. All the infants were born full term. No family history and no associated abnormalities were noted. The mean age at first admission was 20 (1-136) days and mean age at diagnosis was 166 (5-623) days. Swenson's pull-through (two- or three-stage procedure) was carried out in all patients at the mean age of 18.6 months. The extent of aganglionosis was rectosigmoid colon in 10 patients (77%) and one patient had total colonic aganglionosis. Postoperative complications occurred in seven patients (53%), adhesion ileus being the most common complication. Long term bowel function was satisfactory in 85% of the patients. CONCLUSIONS: The incidence of Hirschprung's disease in Iceland is low. Mean age at diagnosis is six months. Sixty percent of the children are discharged with a wrong diagnosis after first admission to hospital and this could be improved by diagnosing the disease at an earlier stage. Postoperative complications are common but no deaths occurred. Bowel function following definitive correction is good compared to other studies.

English Abstract↗

PubMed1998

Scoring oral mucositis.

Oral mucositis is a common, dose limiting and potentially serious complication of both radiation and chemotherapy. Both these therapies are non-specific, interfering with the cellular homeostasis of both malignant and normal host cells. An important effect is the loss of the rapidly proliferating epithelial cells in the oral cavity, gut and in the bone marrow. Within the mouth, the loss of these cells leads to mucosal atrophy, necrosis and ulceration. Although post-treatment healing is generally uneventful, severe mucositis can be life threatening, especially if complicated by dehydration or secondary infection. Accurate and reproducible evaluation of oral mucositis is important in order to monitor patient toxicity during therapy, to document the toxicity of conventional therapy and to critically assess the effects of alternative therapies. A number of oral toxicity scoring systems have been described, but direct comparisons have rarely been undertaken and little data exist regarding inter- and intra-user reliability. This paper reviews a number of oral mucositis scoring systems that are commonly used and will also discuss, briefly, the biological basis of its development and management.

Antineoplastic Agents↗

PubMed1993

Phase I pharmacokinetic study of cyclosporin A combined with doxorubicin.

We performed a phase I trial of cyclosporin A (CsA) in combination with doxorubicin (dox) to determine the maximally tolerated dose (MTD) of the combination in man, to define the quantitative and qualitative toxicities of the combination, and to determine the pharmacokinetics of the two drugs when used together. CsA was administered as a continuous infusion for 6 days, and dox was administered as a single 10-min infusion 24 h after the initiation of CsA. The starting CsA infusion rate was 5 micrograms/kg/min, and the dox starting dose was 30 mg/m2. Courses were administered every 4 weeks with first CsA and then dox being escalated in consecutive cohorts of patients until the MTD was determined. Twenty-three patients and 40 courses were evaluable for toxicity. Pharmacokinetic analysis was performed in 23 patients on the first course for whole blood CsA and plasma dox and doxorubicinol. The MTD of CsA was 6 micrograms/kg/min, and for dox it was 45 mg/m2. Dose-limiting toxicity was neutropenia. Serum creatinine and creatinine clearance did not change over the infusion period. Bilirubin increased from a median of 10 mumol/liter at the initiation of the infusion to a median of 40.4 mumol/liter at the end of the infusion but returned to normal before the next cycle of therapy. Nausea and vomiting were common and marked, whereas thrombocytopenia was mild. Two patients, one with small cell lung cancer and one with breast cancer, had stable disease while receiving treatment for 5 and 6 months, respectively. Mean whole blood steady state concentrations of CsA were 2210 ng/ml during the infusion with total body clearance of 0.177 liter/h/kg. The area under the concentration x time curve (AUC) increased linearly with dose of dox, and total body clearance was independent of dose. The mean total body clearance was 2.46 liters/h/m2, and terminal half-life was 49.6 h. The AUC for dox was greater and clearance was less than has been previously reported at the doses administered in this study. The ratio of AUC for doxorubicinol to AUC for dox was less than expected, suggesting that the metabolism and/or excretion of dox was decreased when administered with CsA. We conclude that dox can be combined with infusioned CsA but at a lower dose than when given alone. This may be due to altered metabolism and/or excretion of dox or increased bone marrow stem cell sensitivity to dox.

Adult↗