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Biomedical subjects

P Kusumakumary

Publications and source records attributed to P Kusumakumary.

At least 19 recordsLinked to original sources
PubMed2005

DNA repair gene XRCC1 polymorphisms in childhood acute lymphoblastic leukemia.

Defective DNA repair has been reported to be a risk factor for various malignancies. Genetic polymorphisms of DNA repair genes are thought to result in different phenotypic features compared to the wild type. Genetic polymorphisms in XRCC1 gene could, through alteration of protein structure, lead to defective functioning of DNA Polbeta, PARP and LIG3 enzymes resulting in defective DNA repair and increased risk of childhood acute lymphoblastic leukemia (ALL). The role of DNA repair gene XRCC1 in susceptibility to childhood ALL has, however, not been widely studied and no data exists from Indian children. In this pilot study, through the use of PCR and RFLP, further confirmed by DNA sequencing, we have shown an increased risk of ALL among children with XRCC1 codons 194 and 399 variant genotypes. Among the three variants, only the association between codon 399 variant and risk of ALL appeared to be significant. The risk of ALL was higher in males with codons 194 and 399 polymorphisms than in females. However, no relation was found between the presence of these variant genotypes and treatment outcome.

Child↗
PubMed2004

Genetic polymorphism of CYP1A1, CYP2D6, GSTM1 and GSTT1 and susceptibility to acute lymphoblastic leukaemia in Indian children.

BACKGROUND: Biotransformation plays a crucial role in carcinogen activity and many genetic polymorphisms in xenobiotic metabolising enzymes have been associated with an increased risk of cancer. Such polymorphisms can lead to considerable variation in the activities of these enzymes, which are crucial in carcinogen and drug metabolism. These variations could play a role in the risk of developing paediatric acute lymphoblastic leukaemia (ALL) by their varying action on environmental carcinogens. PROCEDURE: The present study looked for two polymorphisms (m1 and m2) in the CYP1A1, CYP2D6*4 genes and deletions of the glutathione S-transferases (GSTM1 and GSTT1) in 118 paediatric ALL patients and 118 age matched control children. The polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to study gene polymorphisms. RESULTS: In children with ALL, CYP1A1 m1 polymorphism was evident in 42.4% of subjects and CYP1A1 m2 in 37.3%. These were significantly different from the results obtained for control children (20.3% for CYP1A1 m1 and 19.5% for m2). Subjects with CYP1A1 m1 homozygous variant had a sixfold risk and CYP1A1 m2 a fourfold risk. In contrast, CYP2D6*4 was more prevalent in the controls than in the cases. Subjects with GSTM1 deletions had increased risk of ALL (OR = 2.1, P = 0.009). The odds ratios for both CYP1A1 m1 and m2 homozygous polymorphisms being associated with childhood ALL was 5.67 (95% CI = 2.11-15.27). The odds ratios for both GSTM1 and GSTT1 deletions being associated with ALL was 2.78 (95% CI = 0.67-11.56). CONCLUSIONS: These results suggest that genetic polymorphisms of xenobiotic metabolising enzymes appear to influence susceptibility to childhood ALL.

Adolescent↗
PubMed2004

In vitro drug sensitivity and apoptosis induction in newly diagnosed pediatric acute lymphoblastic leukemia: correlation with overall survival.

The present study looked for any associations between in vitro drug sensitivity and clinical outcome in pediatric acute lymphoblastic leukemia (ALL) with the standard drugs used for leukemia therapy. A total of 72 samples were analyzed. In vitro sensitivity to drugs was tested by a methylthiazol-tetrazolium assay in 6 serial fold dilutions. Apoptosis was determined by TUNEL assay and apoptotic index was calculated for each sample. Patients sensitive to prednisone, asparginase, vincristine, and 6-mercapto purine had higher overall survival compared to patients whose tumor cells were resistant to these drugs (p < .01). For the other drugs tested, overall survival did not vary from that of the resistant patients. For doxorubicin, asparginase, vincristine, prednisone combination sensitivity, there was a significant worsening of prognosis from the extremely sensitive patients through an intermediate sensitive group to a most resistant group. The present study thus shows that in vitro drug-sensitivity testing provides significant prognostic information in childhood ALL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Metastatic osteosarcoma causing intussusception.

Osteosarcoma is the most common malignant bone neoplasm. It has a very high metastatic potential, and lungs are the most common site of metastasis followed by bones. Multiagent chemotherapy has been reported to alter the biological behavior of the disease so that the tumor metastasizes to more rare sites such as brain, bowel, and soft tissues. The authors report a case of jejuno-jejunal intussusception caused by metastases from osteosarcoma.

Bone Neoplasms↗
PubMed2002

Expression of folate sensitive and aphidicolin induced chromosomal fragile sites in familial neuroblastoma.

The expression of folate sensitive and aphidicolin induced fragile sites in the blood lymphocyte chromosomes of affected and unaffected members from 2 neuroblastoma families were studied. The subjects included 4 neuroblastoma patients, and 9 of their clinically healthy first degree relatives and corresponding number of age and sex matched controls. Lymphocytes cultured in folate deprived culture medium showed rare fragile sites at band p13.1 of chromosome 1, in a frequency of 3%-5% in all the 4 neuroblastoma patients. In aphidicolin treated cultures, the patients and unaffected members in neuroblastoma families, showed hypersensitivity to aphidicolin, as evidenced by the significant increase in percentage of aberration/cell (ab/c) and damaged cells (dc), over that of controls (P < 0.01). Aphidicolin induced fragile sites were more pronounced in chromosomes 1 and 2. A larger number of subjects have to be studied to prove whether altered fragile site expression may be a cytogenetic evidence for an individual or familial cancer predisposing genetic constitution.

Aphidicolin↗
PubMed2000

Mutant p53 protein, Bcl-2/Bax ratios and apoptosis in paediatric acute lymphoblastic leukaemia.

PURPOSE: The Bcl-2 family of proteins regulates a late step in the apoptosis pathway. Bcl-2 protein is believed to be involved in imparting resistance to programmed cell death or apoptosis induced by chemotherapeutic agents and radiation. The anti-apoptotic function of the Bcl-2 protein appears to be modulated by its ability to heterodimerize with other members of the gene family, predominantly Bax, a protein favouring induction of apoptosis. Susceptibility to undergoing apoptosis may, therefore, be dependent on the ratio between Bcl-2 and Bax. Both Bax and Bcl-2 are regulated by the tumour-suppressor protein p53. The present study therefore aims to study the significance of the Bcl-2:Bax ratio, p53 expression and apoptosis in paediatric acute lymphoblastic leukaemia (ALL). METHODS: Expression of Bax, Bcl-2 and p53 was determined by immunocytochemistry, and apoptosis was evaluated by an enzymatic end-labelling technique using biotin-dUTP and further confirmed by annexin binding. The presence of mutant p53 was determined using a mutant-p53-specific enzyme-linked immunosorbent assay (ELISA). RESULTS: A total of 32 cases and 20 controls were evaluated. Bcl-2 was found to be expressed in 22/32 of the ALL cases. Pretreatment (spontaneous) apoptosis was observed in 23/32 cases. The mean pretreatment apoptotic index was 11.34 +/- 2.04% with a median value of 7.5%. CONCLUSIONS: There was a positive correlation between apoptosis and Bax expression (r = 0.5044; P = 0.0038). There was good correlation between the immunoreactivity of p53 and detection of mutant p53 by ELISA (r = 0.4605; P = 0.0079). The apoptosis index showed a negative borderline correlation to the expression of Bcl-2 protein (r = -0.3181; P = 0.076). There was an inverse correlation between extent of apoptosis and the presence of mutant p53 protein (r = -0.4732; P = 0.006). p53 protein expression also showed a correlation with both Bcl-2 (r = 0.4647; P = 0.007) and Bax (r = 0.4128; P = 0.018). The Bcl-2/Bax ratio, however, showed no significant correlation with apoptosis (r = -0.3131; P = 0.08) or with p53 expression. No significant association was evident between clinical and laboratory parameters with the Bcl-2/Bax protein expression except lymphadenopathy (r = 0.5774; P = 0.03). However, Bax expression showed a borderline correlation with the immediate tumour response to chemotherapy (r = -0.338; P = 0.0628). These patients are being followed-up to look for any association between clinical outcome, Bcl-2/Bax ratio and apoptosis.

Apoptosis↗
PubMed1999

Disseminated Langerhans cell histocytosis in children: treatment outcome.

Langerhans cell histiocytosis is an interesting disorder with a variety of presentations and variable outcomes. This study evaluates response to treatment, recurrence, and survival in disseminated Langerhans cell histiocytosis treated at Regional Cancer Centre, Trivandrum, India from 1983 through 1994. Thirty-five patients with disseminated Langerhans cell histiocytosis were seen. Six had group A disease, 21 had group B disease, and eight had group C disease. In group A, five of six patients are disease free at a median follow-up of 48 months. Two had recurrence after initial treatment, which was salvaged. In group B, 13 of 15 patients had complete response after chemotherapy, nine of whom experienced recurrence later. Three of five patients who received irradiation alone experienced recurrence. One died of progressive disease. Two patients were lost to follow-up. Seventeen of 20 are alive with median follow-up of 67 months. In group C, one of eight patients are alive after multiple recurrences. Of the surviving patients, 29% had significant sequelae. In summary, group A and B patients do well with treatment, and most of the recurrences can be salvaged. A significant proportion of patients have sequelae. Newer aggressive protocols must be developed for treating group C patients. Measures to prevent sequelae must also be developed.

Adolescent↗
PubMed1998

Extragonadal germ-cell tumors: a ten-year experience.

Extragonadal germ-cell tumors (EGCT) are uncommon and biologically distinct from their gonadal counterparts. Thirty-seven patients who had EGCT were treated over a ten-year period at the Regional Cancer Centre, Trivandrum, India. There were 26 men and boys and 11 women and girls. The sites of primary tumor were mediastinum (n=18), central nervous system (n=5), sacrococcygeal region (n=4), retroperitoneum (n=2), and other sites (n=8). After combined modality therapy, 13 of 18 patients who had mediastinal EGCT--1 of 2 with retroperitoneal, 1 of 4 with sacrococcygeal, 0 of 5 with central nervous system, and 2 of 8 patients with tumor in other sites-were alive with no evidence of disease at a median follow-up of 16 months. The overall 5-year survival rate was 40%. Histologic subtype and elevated marker levels were the significant prognostic factors on univariate analysis.

Adolescent↗
PubMed1998

Bcl-2 protein and apoptosis in pediatric acute lymphoblastic leukemia.

Many chemotherapeutic agents are thought to exert their genotoxic effects through induction of programmed cell death (PCD) (apoptosis) in tumor cells. The bcl-2 is an anti-apoptotic oncoprotein and can confer a survival advantage to tumor cells by preventing apoptosis. Overexpression of bcl-2 may therefore be implicated in resistance to chemotherapy. We studied the significance of bcl-2 expression and the PCD index in pediatric acute lymphoblastic leukemia. Evaluation of bcl-2 by immunocytochemistry and PCD by an enzymatic end labelling technique using biotin-dUTP was carried out in a total of 55 cases and 40 controls. Bcl-2 was found to be expressed in 47% (26/55) of the acute lymphoblastic leukemia cases. The positive cells varied from 0-49% among individual samples. Pre-treatment (spontaneous) apoptosis was observed in 62% (34/55) cases. The mean pre-treatment PCD index was 8.27 1.3%, while the median PCD index was 5. The PCD value for the leukemic samples analyzed were then classified as either high apoptosis values ( 5) and low apoptosis values (<5). PCD index was high in 53% (29/55) and low in 47% (26/55). However, 23% (13/55) of cases did not show presence of either apoptosis or bcl-2. There was no association between clinical and laboratory parameters with the apoptotic index or bcl-2 protein expression. However, evaluation of apoptotic index and bcl-2 expression on day 7 of induction chemotherapy showed a borderline correlation between these markers and initial WBC count, presence of mediastinal mass and hepatosplenomegaly. Follow-up of these patients is being done to look for any association between treatment response and apoptosis.

Antineoplastic Agents↗
PubMed1998

Pattern and outcome of neuroblastoma. A 10 year study.

OBJECTIVE: To determine the clinical pattern and outcome of children with neuroblastoma. DESIGN: Retrospective analysis. SETTING: Hospital based information from the case sheets. SUBJECTS: 91 children with age upto 14 years treated in the Regional Cancer Center, Trivandrum. METHODS: Clinical presentation, metastatic pattern and treatment outcome were analyzed. RESULTS: Median age of the study group was 2.5 years with a male:female ratio of 1.6:1. Fifteen per cent children had early stage disease and 85% advanced disease. Five children with stage III and 22 with stage IV disease did not receive may active treatment. The remaining 64 children were evaluated for this analysis with a survival rate of 25%. Two of the four (50%) stage I, four of the six (83.3%) stage II, five of the 18 (27.7%) stage III, three of the 32 (9%) stage IV and two of the four (50%) stage IVs patients are long term survivors. CONCLUSIONS: Majority of the children (> 80%) presented with advanced disease and outcome remained poor. Only 27% of stage III and 9% of stage IV patients are long term survivors in our series. In future, approaches to detect disease at an early stage and aggressive therapeutic strategies in selected patients may improve survival.

Adolescent↗
PubMed1997

Late recurrence of clear cell sarcoma of the kidney.

Clear cell sarcoma of the kidney (CCSK) is a rare pediatric neoplasm with particular propensity for bone metastasis that requires aggressive therapy. We report a patient with CCSK who was misreported as having Wilm's tumour at the time of initial diagnosis and received only minimal therapy. The disease recurred locally-after 8 years, with no evidence of distant metastasis. Important clinical and histologic features of CCSK are described, along with a review of the literature.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Increased levels of mutagen-induced chromosome breakage in Down syndrome children with malignancy.

Even though an association between Down syndrome (DS) and malignancies has been established, the mechanism behind this is still unclear. We therefore investigated constitutional chromosomal abnormalities and bleomycin-induced chromosome sensitivity in 12 DS children, 8 DS children with malignancies, and 10 normal controls to explore whether these factors play any role in cancer predisposition. Trisomy 21 was the only constitutional cytogenetic abnormality observed in all the DS children. But there was significant variation between the patients and controls with regard to bleomycin sensitivity. Compared to the normal controls, all the DS patients expressed significantly higher chromosomal breaks per cell (b/c) values indicating sensitivity to bleomycin. Furthermore, DS children with malignancies demonstrated significantly higher b/c values than DS children with malignancies. These results permit us to assume that DS children showing mutagen hypersensitivity may be having defective DNA repair competence and hence may be predisposed to malignancies.

Child, Preschool↗
PubMed1996

Argyrophilic nuclear organizer regions (AgNORs) in pediatric acute lymphoblastic leukemia.

Nuclear organizer regions (NORs) code for ribosomal RNA and are associated with non-histone nucleoproteins which can be identified by silver staining (AgNORs). AgNORs have been correlated to proliferative activity of tumors and hence may be prognosis-related. The present study evaluates the possible prognostic importance of the AgNORs in tumor cells of patients with pediatric acute lymphoblastic leukemia (ALL). A significant increase in AgNOR counts was observed in ALL patients as compared to normal controls. Further, a significant positive correlation was observed between AgNOR counts and total WBC count at diagnosis. A negative correlation was also observed between AgNOR counts and age of the patients. Logistic regression analysis revealed further correlation between AgNOR counts and disease with an odds ratio of 1.29 (P = 0.03) as compared to normal controls. These results therefore suggest that AgNOR counts may be significant in the evaluation of pediatric ALL.

Case-Control Studies↗