Search PubMed⌕ Search

Biomedical subjects

E Kane

Publications and source records attributed to E Kane.

At least 19 recordsLinked to original sources

Diesel exhaust particle-induced alterations of pulmonary phase I and phase II enzymes of rats.

Although diesel exhaust particles (DEP) are known to produce pulmonary disorders, the xenobiotic metabolic pathways associated with DEP detoxification and bioactivation remain unclear. In this study, the effect of acute exposure of DEP on phase I and phase II enzymes of rat lung was investigated. Intratracheal administration of DEP produced an induction of cytochrome P-450 (CYP) 1A1 enzyme protein and activity at 1 d postexposure, with the enzyme level returning to control at 5 d postexposure. On the other hand, carbon black (CB), a particle control, did not show any induction of CYP1A1 protein or enzyme activity. However, both DEP and CB significantly decreased CYP2B1 protein and enzyme activity at 1 d postexposure. The decrease in CYP2B1 enzyme protein and activity by DEP or CB treatment was observed up to 7 d postexposure. DEP and CB treatments also significantly attenuated glutathione S-transferase (GST)-pi protein at 1 d postexposure. Both DEP and CB at 35 mg/kg significantly decreased the activities of GST and catalase at 1 and 7 d postexposure. DEP, but not CB, significantly induced quinone reductase (QR) activity at 7 d postexposure. This study suggests that DEP may induce CYP1A1 and QR enzymes via a chemical effect, while the carbonaceous core may be involved in the attenuation of CYP2B1, GST, and catalase proteins and enzyme activities.

Animals↗

Low NAD(P)H:quinone oxidoreductase 1 activity is associated with increased risk of acute leukemia in adults.

NAD(P)H:quinone oxidoreductase 1 (NQO1) is an enzyme that detoxifies quinones and reduces oxidative stress. A cysteine-to-threonine (C --> T) substitution polymorphism at nucleotide 609 of the NQO1 complementary DNA (NQO1 C609T) results in a lowering of NQO1 activity. Individuals homozygous for this mutation have no NQO1 activity, and heterozygotes have low to intermediate activity compared with people with wild type. DNA samples from 493 adult de novo acute leukemia patients and 838 matched controls were genotyped for NQO1 C609T. The majority of cases were diagnosed as acute myeloid leukemia (AML) (n = 420); 67 as acute lymphoblastic leukemia (ALL); and 6 as other forms of acute leukemia. The frequency of cases with low or null NQO1 activity (heterozygote + homozygous mutant) was significantly higher among total acute leukemia case subjects compared with their matched controls (odds ratio [OR] = 1.49; 95% confidence interval [CI], 1.17-1.89). Both ALL (OR = 1.93; 95% CI, 0.96-3.87) and AML case subjects (OR = 1.47; 95% CI, 1.13-1.90) exhibited a higher frequency of low or null NQO1 genotypes than controls. For de novo AML, the most significant effect of low or null NQO1 activity was observed among the 88 cases harboring translocations and inversions (OR = 2.39; 95% CI, 1.34-4.27) and was especially high for those harboring inv(16) (OR = 8.13; 95% CI, 1.43-46.42). These findings were confirmed in a second group of 217 de novo AML cases with known cytogenetics. Thus, inheritance of NQO1 C609T confers an increased risk of de novo acute leukemia in adults, implicating quinones and related compounds that generate oxidative stress in producing acute leukemia.

Acute Disease↗

Epstein-Barr Virus and HLA-DPB1-*0301 in young adult Hodgkin's disease: evidence for inherited susceptibility to Epstein-Barr Virus in cases that are EBV(+ve).

Cases of Hodgkin's disease (HD) may be distinguished by whether they do [EBV-positive ((+ve)) cases] or do not [EBV-negative ((-ve)) cases] have evidence of EBV DNA in the Reed-Sternberg cells. Only one study has attempted to distinguish epidemiological risk factors for EBV(+ve) and EBV(-ve) HD, and none have compared inherited susceptibility. The present study involves a population-based case series of HD, diagnosed in patients between 16-24 years of age in the United Kingdom (n = 118), of whom 87% were classified by EBV status (EBV(+ve), 19, EBV(-ve), 84). History of infectious illness, EBV antibody titers, and HLA-DPB1 type have been compared in EBV(+ve) and EBV(-ve) cases. Reported infectious mononucleosis was more frequent in EBV(+ve) cases (odds ratio (OR), 5.10; 95% confidence interval (CI), 1.12-24.4). EBV antibody titers to viral capsid antigen were significantly higher in EBV(+ve) cases (P for trend = 0.02). Higher proportions of EBV(+ve) (43%) than EBV(-ve) (31%) cases typed positive for HLA-DPB1*0301, but this was not statistically significant; the association of infectious mononucleosis with EBV(+ve) cases was stronger in this HLA subgroup (OR, 17.1; 95%CI, 1.06-1177) than in other cases (OR, 1.24; 95% CI, 0.02-15.4). Although these results are based on small numbers of HD cases, they provide suggestive evidence that the etiology of EBV(+ve) HD may involve inherited susceptibility to EBV.

Adolescent↗

Risk factors for Hodgkin's disease by Epstein-Barr virus (EBV) status: prior infection by EBV and other agents.

A UK population-based case-control study of Hodgkin's disease (HD) in young adults (16-24 years) included 118 cases and 237 controls matched on year of birth, gender and county of residence. The majority (103) of the cases were classified by Epstein-Barr virus (EBV) status (EBV present in Reed-Stenberg cells), with 19 being EBV-positive. Analyses using conditional logistic regression are presented of subject reports of prior infectious disease (infectious mononucleosis (IM), chicken pox, measles, mumps, pertussis and rubella). In these analyses HD cases are compared with matched controls, EBV-positive cases and EBV-negative cases are compared separately with their controls and formal tests of differences of association by EBV status are applied. A prior history of IM was positively associated with HD (odds ratio (OR) = 2.43, 95% confidence interval (CI) = 1.10-5.33) and with EBV-positive HD (OR = 9.16, 95% CI = 1.07-78.31) and the difference between EBV-positive and EBV-negative HD was statistically significant (P = 0.013). The remaining infectious illnesses (combined) were negatively associated with HD, EBV-positive HD and EBV-negative HD (in the total series, for > or =2 episodes compared with < or =1, OR = 0.45, 95% CI = 0.25-0.83). These results support previous evidence that early exposure to infection protects against HD and that IM increases subsequent risk; the comparisons of EBV-positive and EBV-negative HD are new and generate hypotheses for further study.

Adolescent↗

Polymorphic variation within the glutathione S-transferase genes and risk of adult acute leukaemia.

Polymorphisms within the phase II metabolizer enzymes GST T1, GST M1 and GST P1 affect the body's ability to detoxify a range of potential leukaemogens encountered in the environment. Using PCR, GST T1, GST M1 and GST P1 genotypes were determined in 557 adults with acute leukaemia and 952 age, sex and geographically matched controls. The strongest association with acute leukaemia was observed for the GST T1 null genotype, which occurred among 19% of cases and 14% of controls [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.09-1.93]. A slightly higher proportion of cases (53%) than controls (49%) displayed the GST M1 null genotype, although the difference was not statistically significant (OR 1.22, 95% CI 0.98-1.52). No effect was observed for the GST P1 genotype and no interaction between the GST T1 and GST M1 genotypes was evident. Acute myeloid leukaemia (AML) was weakly associated with both GST T1 null (OR 1.32, 95% CI 0.97-1.79) and GST M1 null (OR 1. 24, 95% CI 0.98-1.56), whereas acute lymphoblastic leukaemia (ALL) was associated with GST T1 null (OR 3.28, 95% CI 1.31-8.26). No associations between smoking and disease risk in relation to GST T1 and GST M1 polymorphic status were found.

Adolescent↗

Poor metabolizers at the cytochrome P450 2D6 and 2C19 loci are at increased risk of developing adult acute leukaemia.

We have genotyped over 550 cases of acute leukaemia and 950 matched controls from a population-based case-control study, to investigate the impact cytochrome P450s 2D6, 2C19 and 1A1 have on susceptibility to adult acute leukaemia. Analysis included potential associations between polymorphic status and acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL), plus the FAB and cytogenetic subtypes therein. A significant increased risk was found for CYP2D6 poor metabolizer phenotype and acute leukaemia [odds ratio (OR) = 1.69, 95% confidence interval (CI) 1.17-2.43], a risk also found in AML and ALL. No interaction was found with smoking. However, a significant age-related association between CYP2D6 polymorphism and acute myeloid leukaemia implied that the excess risk was confined to persons aged 40 years and over (OR 2.38, 95% CI 1.53-3.71). Amongst AML cases, increased odds ratios were observed in both de-novo (OR 1.54, 95% CI 1.02-2.32) and secondary leukaemia (OR 2.83, 95% CI 0.91-8.77), and among patients with a chromosomal abnormality (OR 2.00, 95% CI 1.11-3.61). An increased risk was found for the CYP2C19 poor metabolizer phenotype (OR 1.68, 95% CI 0.97-2.92) which was also present in AML and ALL. For this CYP450 locus, an increased risk was suggested in secondary leukaemia (OR 2.67, 95% CI 0.44-16.3) and amongst AML cases with a chromosomal abnormality (OR 6.72, 95% CI 2.22-20.4). No difference in CYP1A1 genotype distribution was found for acute leukaemia, AML, ALL or any other diagnostic classification group used. No significant interactions between CYP2D6, CYP2C19 or CYP1A1 were found.

Acute Disease↗

Polymorphisms in the methylenetetrahydrofolate reductase gene are associated with susceptibility to acute leukemia in adults.

Reduction of 5,10-methylenetetrahydrofolate (methyleneTHF), a donor for methylating dUMP to dTMP in DNA synthesis, to 5-methyltetrahydrofolate (methylTHF), the primary methyl donor for methionine synthesis, is catalyzed by 5,10-methylenetetrahydrofolate reductase (MTHFR). A common 677 C --> T polymorphism in the MTHFR gene results in thermolability and reduced MTHFR activity that decreases the pool of methylTHF and increases the pool of methyleneTHF. Recently, another polymorphism in MTHFR (1298 A --> C) has been identified that also results in diminished enzyme activity. We tested whether carriers of these variant alleles are protected from adult acute leukemia. We analyzed DNA from a case-control study in the United Kingdom of 308 adult acute leukemia patients and 491 age- and sex-matched controls. MTHFR variant alleles were determined by a PCR-restriction fragment length polymorphism assay. The MTHFR 677TT genotype was lower among 71 acute lymphocytic leukemia (ALL) cases compared with 114 controls, conferring a 4.3-fold decrease in risk of ALL [odds ratio (OR = 0.23; 95% CI = 0.06-0.81]. We observed a 3-fold reduction in risk of ALL in individuals with the MTHFR 1298AC polymorphism (OR = 0.33; 95% CI = 0.15-0.73) and a 14-fold decreased risk of ALL in those with the MTHFR 1298CC variant allele (OR = 0.07; 95% CI = 0.00-1.77). In acute myeloid leukemia, no significant difference in MTHFR 677 and 1298 genotype frequencies was observed between 237 cases and 377 controls. Individuals with the MTHFR 677TT, 1298AC, and 1298CC genotypes have a decreased risk of adult ALL, but not acute myeloid leukemia, which suggests that folate inadequacy may play a key role in the development of ALL.

Acute Disease↗

Epstein-Barr virus and Hodgkin's disease: further evidence for the three disease hypothesis.

The epidemiology of Hodgkin's disease suggests that it is a heterogeneous condition comprising more than one disease entity. The Epstein-Barr virus (EBV) is present in the Reed-Sternberg cells of a proportion of cases and is likely to play a role in the pathogenesis of these cases. In this study we show that EBV association rates vary with age at diagnosis. We suggest that Hodgkin's disease can be divided into three disease entities on the basis of EBV association and age, thereby providing biological support for the multiple aetiology hypothesis proposed by MacMahon (Cancer Res 1966; 26: 1189-1290).

Adolescent↗

Determination of HLA-A*02 antigen status in Hodgkin's disease and analysis of an HLA-A*02-restricted epitope of the Epstein-Barr virus LMP-2 protein.

There is good evidence for an association between Epstein-Barr virus (EBV) and Hodgkin's disease (HD). In approximately one-third of cases, the EBV genome is detectable in Reed-Sternberg (RS) cells and there is expression of the viral nuclear antigen EBNA-1 and the latent membrane protein LMP-1. Expression of LMP-2 has been demonstrated at the mRNA level, and it is presumed that the protein is expressed alongside LMP-1. The LMP-2 protein is known to contain an epitope presented to cytotoxic T-cells which is restricted through the HLA class I antigen A*0201 in healthy seropositive individuals. Since most HLA-A*02-positive Caucasians are HLA-A*0201-positive, it was hypothesized that HLA-A*02-positive individuals would be under-represented among Caucasians with EBV-associated HD. HLA-A*02 status was determined, using flow cytometry and/or the polymerase chain reaction, for 276 individuals including 176 cases of HD. There was no significant difference between the frequency of HLA-A*02 positivity in HD cases and controls, and between EBV-associated and non-associated cases of HD. The A*02 alleles of 14 cases of EBV-associated HD were further subtyped using nested PCR; all except one case were found to be A*0201-positive. We therefore investigated whether there was any evidence for mutation of the epitope representing amino acids 426-434 of LMP-2a which is restricted through HLA-A*0201. In 10/11 cases the nucleotide sequence encoding this epitope was identical to the published sequence; in the remaining case there was a mutation which would not be expected to alter the conformation of the epitope. Overall, our data suggest that other mechanisms of immune escape must be operative in EBV-associated HD.

Adolescent↗

Infusion pumps for systemic and intra-arterial chemotherapy of colorectal liver metastases.

Over a 12 month period, we prospectively evaluated the use of an ambulatory infusion pump for intra-arterial and intravenous chemotherapy in patients with colorectal liver metastases. In all, 274 separate infusions were given with minor complications occurring on six occasions. Administering treatment on an outpatient basis rather than as an inpatient has resulted in savings of over Pounds 17000 in the first year.

Adult↗

Anatomical basis of intra-arterial chemotherapy for patients with locally advanced breast cancer.

Twenty-eight patients with locally advanced breast cancer received four doses of regional chemotherapy via angiographically placed percutaneous catheters into the internal mammary artery (IMA) and lateral thoracic artery. Patent blue dye was injected to outline the relative contribution to perfusion of each of these vessels. The IMA was found to perfuse 67 (range 20-95) per cent of the breast and the lateral thoracic artery 15 (range 0-35) per cent. In 33 per cent of patients the lateral thoracic artery did not contribute to breast perfusion and a large area of the lateral aspect of the breast was perfused from a further branch of the subclavian or axillary artery. The blood supply to the breast is extremely variable and must be determined in each patient before delivering regional chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

Rectal expulsion of a hepatic artery catheter.

The outlook for patients with colorectal liver metastases remains poor, survival in our hospital being only 6 months. The results of conventional treatment are disappointing. With the advent of implantable silicone catheters and small portable pumps, regional chemotherapy is more frequently administered, although complications relating to the catheter do occur. We describe a patient who expelled his hepatic artery catheter rectally, following removal of the catheter port for sepsis.

Aged↗

A phase II study of regional 5-fluorouracil infusion with intravenous folinic acid for colorectal liver metastases.

Regional chemotherapy, delivered via the hepatic artery, may significantly increase tumour response rates in patients with colorectal liver metastases. However, survival is limited by extrahepatic disease progression. We have developed a novel therapeutic approach for patients with metastases confined to the liver. In order to achieve high local response rates and also inhibit extrahepatic progression, 5-fluorouracil (5-FU) was infused intra-arterially at a dose previously calculated to achieve both high-dose regional therapy and adequate systemic levels. To enhance efficacy further, 5-FU was combined with high-dose systemic folinic acid (FA). Thirty-one patients were evaluated in a phase II study. 5-FU (1.5 g m2) was infused via a surgically implanted hepatic artery catheter over a 24 h period; FA (total 400 mg m-2) was infused intravenously during the initial and final 2 h. Treatments were given weekly for cycles of 6 weeks' duration. To date, median duration of treatment is 6 months and the median follow-up period is 17 months. The overall response rate was 48% with two complete and 13 partial responses. Predicted median time to progression is 8 months. The site of first progression was hepatic in 10 (42%) and extrahepatic in 14 (58%) patients. Seven patients developed local complications; one required emergency surgery. Side-effects were limited to grade 3 toxicity (four patients) or less. Predicted median survival is 19 months. This approach, which is associated with a high response rate and low systemic toxicity, warrants further evaluation. A phase III study is planned.

Adult↗