PubMed Health⌕ Search

Biomedical subjects

A De Groot

Publications and source records attributed to A De Groot.

10 recordsLinked to original sources
PubMed1998

Synthesis and antiviral activity of 7-O-(omega-substituted)-alkyl-3-O-methylquercetin derivatives.

3',4'-Di-O-benzyl-3-O-methylquercetin (2), the precursor in the synthesis of an important antivirally active flavone 3-O-methylquercetin (1), was regioselectively alkylated at the 7-OH position by a series of 1,omega-dihaloalkanes and omega-bromoalkanols. Dimerization of the flavone had to be avoided by applying strict reaction conditions. Subsequent debenzylation was carried out by catalytic transfer hydrogenolysis, affording quantitatively the 7-O-(omega-haloalkyl)-3-O-methylquercetin (11-14) and 7-O-(omega-hydroxyalkyl)-3-O-methylquercetin derivatives (15, 16). All compounds were tested for their antiviral activity against poliomyelitis- and HIV-viruses.

Animals↗
PubMed1997

Cranial irradiation is the major cause of learning problems in children treated for leukemia and lymphoma: a comparative study.

Prophylactic treatment of the central nervous system (CNS) in childhood leukemia and non-Hodgkin lymphoma (NHL) has negative effects on intelligence. We investigated the clinical significance of this finding by comparing the effect of different types of CNS prophylaxis on the survivor's learning capabilities. To isolate the effect of different types of CNS prophylaxis from other treatment and disease variables on learning problems, children treated for leukemia or NHL who received CNS prophylaxis with cranial irradiation (n = 30) or without cranial irradiation (n = 36) were compared with children treated for solid tumors who received systemic chemotherapy without any CNS treatment (n = 30) and with matched healthy controls (n = 265). The identification of learning problems was based on the school system's assessment. Parents and teachers reported on the child's educational status in a standardized way. Learning problems were found in 80% of children who received CNS prophylaxis with cranial irradiation. This was significantly higher than the 14% found in children treated with CNS prophylaxis without cranial irradiation (P < 0.000). The prevalence of learning problems in this latter group did not differ significantly from that in childhood cancer survivors without any form of CNS prophylaxis (20%) and in healthy matched controls (17%). We conclude that the high prevalence of learning problems in survivors of childhood leukemia and NHL is directly related to CNS prophylaxis with cranial irradiation and not to CNS prophylaxis per se or to other treatment and disease variables.

Central Nervous System↗
PubMed1995

Streptozotocin-induced toxicity in CHO-9 and V79 cells.

The cytotoxicity of streptozotocin (STZ) was investigated in Chinese hamster fibroblast lines (CHO-9 and V79) in comparison to two other alkylating agents, methylnitrosourea (MNU) and ethylnitrosourea (ENU), using cell survival as the endpoint. It was found that V79 cells were far more resistant to methylation induced by STZ and MNU than CHO-9 cells (20 and four times, respectively) but equally sensitive to the ethylating agent ENU. The extent of STZ-induced DNA methylation was estimated by analyzing the extent of O6-metG and N7-metG adducts in the DNA of treated cells through high-performance liquid chromatography (HPLC) with electrochemical detection. The number of adducts as well the efficiencies of their removal from the DNA were similar in both cell lines. The response of these cells to the presence of DNA damage was evaluated by analysis of STZ effects on DNA replication and cell cycle progression. Measurement of [3H]-thymidine incorporation showed a similar pattern of response at the level of inhibition of DNA synthesis in both cell lines. However, analysis of metaphase cells 36 hr after STZ exposure showed an accumulation of cells in the second cycle in the CHO-9 line, indicating induction of a cell cycle arrest. Only a slight effect was observed on cell cycle progression in V79 cells, indicating that the methylation resistance of these cells could be related to their ability to progress through the cell cycle despite the presence of DNA lesions.

Animals↗
PubMed1995

Siblings of childhood cancer survivors: how does this "forgotten" group of children adjust after cessation of successful cancer treatment?

Siblings of childhood cancer patients are labelled the "forgotten children" because they experience significant psychosocial distress and are isolated from support systems inside and outside the family. This study investigates the late consequences of the cancer experience for siblings. 60 siblings of cancer survivors were compared with control subjects on measures of psychosocial adjustment. No differences were found between siblings of cancer survivors and controls on emotional and behavioural problems and competence, suggesting that siblings adjust well to the period after cessation of treatment. The effect of demographic, family and disease-related characteristics on the siblings' psychosocial adjustment was limited. Whereas during treatment many psychosocial problems for siblings have been reported, this does not result in a heightened risk of psychological disturbance for siblings as a late effect. The implications for patient care are discussed.

Adolescent↗
PubMed1995

Late psychosocial consequences for parents of children who survived cancer.

Investigated late psychosocial sequelae in 133 parents of children who survived cancer, using questionnaires developed to measure the specific impact of the disease. Childhood cancer had distinct and persistent late psychosocial effects on parents of survivors. Uncertainty and loneliness were the most reported problems. Demographic and situational characteristics such as being a mother, low SES, no religious affiliation, chronic disease in a family member other than the child surviving cancer, and concurrent stresses increased the risk of reporting late problems. Treatment itself had little or no effect on reported problems. However, when treatment led to long-term sequelae in the child, a significant and specific effect on parental problems was observed. No decline of problems over time was found, which has implications for patient care.

Adaptation, Psychological↗
PubMed1995

Obesity after successful treatment of acute lymphoblastic leukemia in childhood.

Early and late effects of treatment for acute lymphoblastic leukemia (ALL) on weight was retrospectively investigated in 113 children in continuous first remission. Weight was examined at diagnosis up to 10 y after cessation of treatment. There was an increased prevalence of overweight after treatment for ALL which persisted over time. All treatment regimens included corticosteroid therapy, and 52 patients received additional cranial irradiation. Patients treated with and without cranial irradiation did not differ in weight gain, indicating that not cranial irradiation but corticosteroid therapy might explain weight gain in children treated for ALL. Dexamethasone was associated with a significant increase of weight at cessation of treatment. Patients treated with a combination of prednisone and dexamethasone had as a late effect the highest prevalence of obesity (44%). Gender or age at diagnosis were not related to weight gain.

Adolescent↗
PubMedDate not supplied

Impact of childhood leukemia on family planning.

Clinical experiences have indicated that family planning is affected by childhood leukemia. To investigate this issue, 130 mothers and fathers of 68 families with a long-term disease-free survivor were studied using interviews and questionnaires concerning the effects of childhood cancer on family planning. In one third of the families, either one or both partners reported that their child's disease affected their reproductive planning in various ways. The most extreme variations included having completed the family before diagnosis but still having another child versus not having completed the family before diagnosis but refraining from further progeny. More than half of the affected families refrained from having further offspring, delineating psychological motives for their decision. For parents whose family planning is affected by their experiences with childhood leukemia, the decision-making process is an extra burden. Therefore we advocate that support for the parents of a child with cancer should include counseling on progeny, in which both genetic and psychological information should be provided.

Adolescent↗