The role of single nucleotide polymorphisms of the ERCC1 and MMS19 genes in predicting platinum-sensitivity, progression-free and overall survival in advanced epithelial ovarian cancer.

OBJECTIVE: This study aims to assess the role of polymorphisms in DNA repair genes, excision repair cross-complementation group 1 (ERCC1) and methyl-methanesulfonate sensitivity 19 (MMS19), in tumor response to platinum-based chemotherapy and survival in advanced epithelial ovarian cancer (EOC). METHODS: Single nucleotide polymorphism (SNP) analysis was performed on the paraffin-embedded tumor tissue of women with advanced EOC, treated with platinum-based chemotherapy at the University of Oklahoma Health Sciences Center. Polymorphisms from two ERCC1 (codon-118 and C8092A) and three MMS19 (rs2211243, rs2236575 and rs872106) gene loci were evaluated by real time PCR Allelic Discrimination Assay. RESULTS: Genotyping was performed in 107 patients, 45 platinum-sensitive and 62 platinum-resistant. ERCC1, codon-118 and C8092A genotyping was evaluable in 98 and 106 patients respectively and in all 107 patients for MMS19 polymorphisms. No differences were observed in genotype between platinum-sensitive and platinum-resistant patients. Polymorphisms in the ERCC1, codon-118 and MMS19 genes did not correlate with overall survival (OS), although a trend toward improved progression free survival (PFS) was observed in patients expressing the minor (GG) alleles of the rs872106 MMS19 gene. Women homozygous for the ERCC1-C8092A minor (AA) alleles had a significant increase in PFS compared to AC and CC patients and both AA and AC genotypes conferred improved survival over the major (CC) genotype. CONCLUSIONS: Polymorphisms in ERCC1, codon-118 and MMS19 genes are not associated with clinical response to platinum or survival. The ERCC1-C8092A genotypes containing an "A" allele were associated with significant improvement in PFS and OS strengthening the value of this specific genotype in survival.

Self-harm in the UK military.

BACKGROUND: Self-harm in the UK military has variously been estimated at 1-5.6% compared with 4.9% in the general UK population. AIMS: To establish the overall prevalence of self-harm within the UK military, to establish the association between deployment and self-harm and to identify sociodemographic and social factors associated with self-harm within the UK military. METHODS: A cross-sectional postal survey of UK military personnel. RESULTS: There were 9803 respondents. The overall prevalence of self-harm was 2.3% in the UK military. Self-harm was not associated with deployment but was significantly associated with being discharged, separated, of lower rank, female and younger age, reporting no close friends or family, reporting fewer social activities, having spent time in local authority care as a child, and having adversity in family relationships as a child. CONCLUSIONS: Contrary to predictions, self-harm in the UK military is not associated with deployment. It is linked to available social support in childhood and adulthood.

A pair of functionally redundant yeast genes (PPZ1 and PPZ2) encoding type 1-related protein phosphatases function within the PKC1-mediated pathway.

The PKC1 gene of Saccharomyces cerevisiae encodes a homolog of mammalian protein kinase C that is required for yeast cell growth. Loss of PKC1 function results in cell lysis due to an inability to remodel the cell wall properly during growth. The PKC1 gene has been proposed to regulate a bifurcated pathway, on one branch of which function four putative protein kinases that catalyze a linear cascade of protein phosphorylation culminating in the activation of the mitogen-activated protein kinase homolog, Mpk1p. Here we describe two genes whose overexpression suppress both an mpk1 delta mutation and a pkc1 delta mutation. One of these genes is identical to the previously identified PPZ2 gene. The PPZ2 gene is predicted to encode a type 1-related protein phosphatase and is functionally redundant with a closely related gene, designated PPZ1. Deletion of both PPZ1 and PPZ2 resulted in a temperature-dependent cell lysis defect similar to that observed for bck1 delta, mkk1,2 delta, or mpk1 delta mutants. However, ppz1,2 delta mpk1 delta triple mutants displayed a cell lysis defect at all temperatures. The additivity of the ppz1,2 delta defect with the mpk1 delta defect, combined with the results of genetic epistasis experiments, suggested either that the PPZ1- and PPZ2-encoded protein phosphatases function on a branch of the PKC1-mediated pathway different from that defined by the protein kinases or that they play an auxiliary role in the pathway. The other suppressor gene, designated BCK2 (for bypass of C kinase), is predicted to encode a 92-kDa protein that is rich in serine and threonine residues. Genetic interactions between BCK2 and other pathway components suggested that BCK2 functions on a common pathway branch with PPZ1 and PPZ2.

Role of endocytosis and lysosomal pH in uptake of N-(phosphonacetyl)-L-aspartate and its inhibition of pyrimidine synthesis.

The mechanism of uptake and retention of N-(phosphonacetyl)-L-aspartate (PALA) was examined. Uptake of [3H]PALA by Ehrlich ascites tumor cells appeared to be biphasic. A small, variable quantity of PALA associated with cells within 5 min; the significance of this rapid uptake component is unclear. Between 15 min and 5 h, uptake was linear and consistent from experiment to experiment. The properties of the slow phase of PALA uptake are consistent with fluid-phase endocytosis. The intracellular PALA concentration approached the extracellular level very slowly, at a rate of approximately 1%/hr. The velocity of PALA uptake in these cells was proportional to the concentration in the media from 10(-6) to 10(-2) M. Uptake of PALA was identical to that of the extracellular marker inulin. Uptake of both PALA and inulin was inhibited by colchicine and stimulated by phorbol myristate acetate. The microtubule antagonist and the phorbol ester are known to, respectively, inhibit and stimulate endocytosis in other cell types. Phorbol myristate acetate enhanced the ability of PALA to inhibit incorporation of [14C]bicarbonate into pyrimidine nucleotides, presumably through an increase in PALA uptake. This inhibitory action of PALA was almost completely blocked by two agents known to neutralize lysosomal pH, NH4Cl and methylamine. These results suggest that intracellular PALA is initially compartmentalized in a pinosomal vesicle which may later fuse with cellular lysosomes. Neutralization of lysosomal pH prevents the protonation of some or all of the four negatively charged groups found in the structure of PALA which may be necessary for its diffusion across the lysosomal membrane and eventual inhibition of aspartate transcarbamylase in the cytoplasm. Since partitioning of the fully charged molecule into the lipid phase of the plasma membrane for diffusion out of the cell should be minimal, the effects of PALA on cellular metabolism are expected to be prolonged.

Role of uridine triphosphate in the phosphorylation of 1-beta-D-arabinofuranosylcytosine by Ehrlich ascites tumor cells.

Pyrimidine nucleotide pools were investigated as determinants of the rate of phosphorylation of 1-beta-D-arabinofuranosylcytosine (ara-C) by Ehrlich ascites cells and cell extracts. Cells were preincubated for 2 h with 10 microM pyrazofurin, 10 mM glucosamine, 50 microM 3-deazauridine, or 1 mM uridine in order to alter the concentrations of pyrimidine nucleotides. Samples of the cell suspensions were taken for assay of adenosine 5'-triphosphate (ATP), uridine 5'-triphosphate (UTP), cytidine 5'-triphosphate, guanosine 5'-triphosphate, deoxycytidine 5'-triphosphate (dCTP), and deoxythymidine 5'-triphosphate; then 1 microM [3H]ara-C was added and its rate of intracellular uptake was measured for 30 min. 3-Deazauridine lowered dCTP and stimulated ara-C uptake; however, pyrazofurin and glucosamine were potent inhibitors of ara-C uptake although they also decreased dCTP levels. Uridine stimulated ara-C uptake despite an increase in dCTP. A crude cytoplasmic extract was prepared by a procedure which permitted results of ara-C kinase assays to be expressed as pmol per min per 10(6) cells as in the cellular uptake studies. When assayed in the presence of mixtures of ribo- and deoxyribonucleoside triphosphates at concentrations close to their cellular levels, ara-C kinase activity closely approximated the cellular uptake rate for the five incubation conditions. Deletion of cytidine 5'-, guanosine 5'-, or deoxythymidine 5'-triphosphate from the assay mixture had little effect, while deletion of dCTP increased kinase activity 9-fold. Elimination of ATP also did not alter kinase activity in the presence of the remaining five ribo- and deoxyribonucleoside triphosphates; however, deletion of UTP reduced activity to 22% of the rate with the control mixture. When ara-C kinase was assayed with only 3 mM ATP, dCTP was a very potent inhibitor (50% inhibition concentration = 0.4 microM). Inhibition was complete at 10 microM dCTP, a concentration below the intracellular dCTP level in control cells (25 microM). With 0.9 mM UTP, enzyme activity was 2-fold greater in the absence of dCTP and the dCTP was 15-fold less potent as an inhibitor (50% inhibition concentration = 6 microM). We conclude that the actual phosphate donor for the phosphorylation of 1 microM ara-C in Ehrlich cells is UTP and not ATP. These observations suggest that successful combination protocols aimed at stimulating ara-C uptake by means of a decrease in dCTP levels must simultaneously preserve or increase UTP pools.

Inhibition of 1-beta-D-arabinofuranosylcytosine transport and net accumulation by teniposide and etoposide in Ehrlich ascites cells and human leukemic blasts.

The interactions of the epipodophyllotoxins, teniposide (VM-26) and etoposide (VP-16), with the nucleoside carrier were examined with emphasis on their effects on 1-beta-D-arabinofuranosylcytosine (ara-C) transport and net accumulation. VM-26 inhibited ara-C transport by Ehrlich ascites cells within 1 min of exposure, and inhibition was only partially reversed after 45 min in VM-26-free medium. ara-C transport was slowed by 50% by 7 microM VM-26 or by 35 microM VP-16. Since epipodophyllotoxins were noncompetitive inhibitors, fractional inhibition was independent of the ara-C concentration. Analysis of ara-C transport kinetics revealed only a single saturable transport route, and there was no indication of VM-26-insensitive transport. VM-26, VP-16, and ara-C were competitive inhibitors of the specific binding of nitrobenzylthioinosine to the nucleoside carrier with Ki values of 7.4 microM, 23 microM, and 2.2 microM, respectively. The rate of dissociation of nitrobenzylthioinosine (t 1/2 = 20.6 min) was accelerated by 5 microM ara-C (t 1/2 = 18.5 min) but slowed by 100 microM VM-26 (t 1/2 = 34.6). By these criteria, the interaction of VM-26 with the nucleoside carrier was qualitatively similar to that of dipyridamole. Although VM-26 inhibited ara-C transport, it did not significantly slow the rate of net intracellular accumulation of ara-C by Ehrlich cells, presumably because transport capacity far exceeds the capacity for phosphorylation in these cells. In freshly isolated human leukemic blasts, which have far less nucleoside transport activity, inhibition of ara-C accumulation by VM-26 was dependent on the ara-C concentration. At 1 microM ara-C, a concentration where transport was rate limiting for net uptake, VM-26 inhibited accumulation of ara-C over a 60-min time course. At 50 microM ara-C, transport was in excess, and VM-26 did not slow ara-C metabolism.

A prospective study of the effect of alcohol consumption and ADH3 genotype on plasma steroid hormone levels and breast cancer risk.

One suggested mechanism underlying the positive association between alcohol consumption and breast cancer risk is an influence of alcohol on steroid hormone levels. A polymorphism in alcohol dehydrogenase type 3 (ADH3) affects the kinetics of alcohol oxidation and thereby could influence the effect of alcohol consumption on hormone levels. We investigated the ADH3 polymorphism, alcohol intake, and risk of breast cancer in a nested case-control study. Among women in the Nurses' Health Study who gave a blood sample in 1989-1990, 465 incident breast cancer cases were diagnosed before June 1994 and were matched to 621 controls. Using conditional logistic regression, we calculated relative risks and confidence intervals to assess breast cancer risk for ADH3 genotype. Among postmenopausal controls not using hormones at time of blood collection, partial Pearson correlation coefficients were calculated to assess the association between alcohol intake and plasma hormone levels according to ADH3 genotype. No association was observed between ADH3 genotype and overall breast cancer risk (relative risk = 0.9 for slow oxidizers compared with fast; 95% confidence interval = 0.6-1.3). Among postmenopausal women, ADH3 genotype did not modify the weak association observed between alcohol intake and breast cancer risk (P for interaction = 0.45). Statistically significant trends in the relationship between alcohol consumption and hormone level dependent on oxidative capacity (ADH3 genotype) were observed for dehydroepiandrosterone sulfate and sex hormone-binding globulin (P < 0.05). These data suggest that the ADH3 polymorphism modestly influences the response of some plasma hormones to alcohol consumption but is not independently associated with breast cancer risk and does not modify the association between alcohol and breast cancer risk.

Methylation of hamster DNA by the carcinogen N-nitroso-bis (2-oxopropyl)amine.

The alkylation of hamster liver, lung and pancreas DNA by [1-14C]- and [2,3-14C]N-nitrosobis (2-oxopropyl) amine (BOP) has been examined. The specific activity of pancreas DNA after [2,3-14C]BOP administration was only 2% of that when [1-14C]BOP was given. 7-Methylguanine, but not O-6-methylguanine, was found in hydrolysates of liver and pancreas DNA. Nearly equal amount of alkylation were produced in the liver when [1-14C]- and [2,3-14C]BOP were given. At least one-half of the radioactivity in the liver was associated with N-alkylated purines, whereas only 20% was in this form in the pancreas.

Binding of radiolabeled N-(phosphonacetyl)-L-aspartate to aspartate transcarbamylase from Ehrlich ascites tumor cells.

Binding of N-(phosphonacetyl)-[3H]L-aspartate (PALA) to aspartate transcarbamylase (ATCase, EC 2.1.3.1) in crude extracts from Ehrlich ascites tumor cells was examined. At pH 7.4, the dissociation constant was 1.39 +/- 0.22 nM; the maximal binding capacity indicated an average intracellular ATCase concentration of 0.13 microM. The presence of phosphate, MgCl2, or CaCl2 increased the apparent dissociation constant for [3H]PALA without altering the maximal binding capacity. Phosphate, a product of the ATCase reaction, probably acts as a competitor for the PALA binding site; Mg2+ and Ca2+ may inhibit [3H]PALA binding by forming a chelate which reduces the effective concentration of the free [3H]PALA. Carbamyl phosphate was a relatively weak inhibitor of [3H]PALA binding in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffer alone. Addition of NaF, an inhibitor of nonspecific phosphatases, decreased the carbamyl phosphate "Ki" as an inhibitor of [3H]PALA binding to 7 microM, a value close to the Km. NaF appears to act as an inhibitor of carbamyl phosphatase activity present in the cell extract. A first-order dissociation rate constant of 0.050 +/- 0.004 min-1 (T1/2 = 14 min) was determined by following displacement of [3H]PALA with excess unlabeled PALA. The dissociation rate was strongly temperature dependent. A second-order rate constant of 3.6 X 10(7) liters mol-1 min-1 was calculated from this rate constant and the dissociation constant. Using these kinetic constants, a simple computer model predicted that PALA binding to ATCase is 95% complete within 14 min under the conditions of the assay; at intracellular ATCase concentrations, binding is slightly faster. These results are discussed in the context of both the kinetics of inhibition and the reversal of inhibition of pyrimidine synthesis within the intact cell.

The persistence of DNA damage in the pancreas of syrian golden hamsters treated with N-nitrosobis(2-oxopropyl)-amine.

DNA damage was estimated in the liver, pancreas and salivary gland of Syrian hamsters given N-nitrosobis(2-oxopropyl)amine (BOP) by alkaline sucrose gradient centrifugation. A single BOP dose (10 mg/kg) produced in all 3 tissues extensive DNA damage that was largely repaired in the salivary gland by 4 weeks, while in the liver and pancreas, some DNA damage persisted until 4 weeks. When higher BOP doses (20 and 40 mg/kg) were used, considerable DNA damage was still evident in the pancreas, but not in the liver at 6 weeks. Greater damage persisted in hamsters given 40 mg/kg, compared with those administered 20 mg/kg.

Effects of the lipophilic anticancer drug teniposide (VM-26) on membrane transport.

The epipodophyllotoxin glucopyranosides have previously been shown to interact with membrane lipids and to alter the activity of several lipid-embedded membrane proteins. To determine if these agents are acting as general membrane perturbants, we have further examined their effects on membrane processes in Ehrlich ascites tumor cells. [3H]VM-26 and [3H]VP-16 were taken up rapidly and concentrated within the cells in proportion to their lipophilicity. Neither agent was found to have any significant effect on the influx of L-[3H]leucine or alpha-[3H]aminoisobutyric acid. Likewise, these drugs had no significant effects on the hexose transporter. The nucleoside transporter, which is structurally and functionally similar to the hexose transporter, was dramatically affected, however. VM-26 was a non-competitive inhibitor of equilibrium-exchange influx of cytosine arabinoside in Ehrlich cells with a Ki of 15 microM. Equilibrium-exchange influx increased with temperature in control cells (Q10 = 2) but not in VM-26-treated cells; thus, VM-26 was a more potent inhibitor at higher temperatures. VM-26 also significantly reduced zero-trans influx in Ehrlich, P388, L5178Y, and ML-1 cells, and these effects were immediate in onset. VM-26 inhibited high-affinity binding of the nucleoside transport inhibitor nitrobenzylmercaptopurine riboside (NBMPR), but VM-26 enhanced non-specific NBMPR binding to Ehrlich cells. The apparent specificity of the epipodophyllotoxins for the nucleoside transporter is discussed.

10 years' experience treating pancreatic and periampullary cancer.

The records of 136 patients with periampullary and pancreatic carcinoma were reviewed and the information compared with other reported series. The clinical presentation with jaundice without other manifestations is associated with the greatest number of potentially curable tumors. The majority of patients were treated by palliative bypass or had exploration and biopsy only. A tissue diagnosis is not imperative before radical excision, providing a systematic preoperative and operative evaluation indicates tumor. Ligation of the pancreatic duct with external drainage results in low morbidity and mortality and good functional results. Radical pancreaticoduodenectomy done in 21 per cent of our patients offers the best palliation and the only hope for cure.

Community people-pet programs that work.

Excellent models exist for people-pet programs in institutions and in the community. Veterinarians should assess the needs of their local communities and adapt a model program to fit these needs.

Our professional responsibilities relative to human-animal interactions.

An interesting area with great potential for benefiting and enriching the lives and conditions of people and animals is opening to us in research, service and teaching. By working with colleagues in other disciplines, we can develop new and creative ways to realize the great promise inherent in people-animal interactions properly studied and utilized.Veterinarians who understand that a strong human-companion animal bond can augment people's mental and physical states will help develop sound and effective companion animal programs for individuals who are lonely or handicapped and for persons in the school systems of the community, as well as its hospices, nursing and convalescent homes, prisons and other institutions. Children experiencing the deep satisfaction of interacting with animals while young will more likely become responsible pet owners and advocates as adults. The image of the profession is enhanced when children and adults see veterinarians as concerned teachers and compassionate health professionals.We as professionals will be required not only to update our knowledge and skills, but to acquire new knowledge in fields of animal and human behavior, psychology and sociology. We are needed on interdisciplinary research teams to study human-animal interactions. We will also be asked to commit time and personal energies in community programs, sometimes with no remuneration. But if skilled health professionals like veterinarians do not take the lead in establishing sound, long-term companion animal programs in their own communities, everyone will suffer including the animals. How we, as individual professionals, respond will be an important reflection of our compassion and our humanity.

Evaluation of Pharmacy and Therapeutic (P&T) Committee member knowledge, attitudes and ability regarding the use of comparative effectiveness research (CER) in health care decision-making.

BACKGROUND: Comparative effectiveness research (CER) is a constellation of research methods designed to improve health care decision making. Educational programs that improve health care decision makers' CER knowledge and awareness may ultimately lead to more cost-effective use of health care resources. OBJECTIVES: This study was conducted to evaluate changes in CER knowledge, attitudes, and ability among Pharmacy and Therapeutics (P&T) Committee members and support staff after attending a tailored educational program. METHODS: Physicians and pharmacists from two professional societies and the Indian Health Service who participated in the P&T process were invited via email to participate in this study. Participants completed a questionnaire, designed specifically for this study, prior to and following the 4-hour live, educational program on CER to determine the impact on their related knowledge, attitudes, and ability to use CER in decision-making. Rasch analysis was used to assess validity and reliability of subsections of the questionnaire and regression analysis was used to assess programmatic impact on CER knowledge, attitude, and ability. RESULTS: One hundred and forty of the 199 participants completed both the pre- and post-CER session questionnaires (response rate = 70.4%). Most participants (>75%) correctly answered eight of the ten knowledge items after attending the educational session. More than 60% of the respondents had a positive attitude toward CER both before and after the program. Compared to baseline (pretest), participants reported significant improvements in their perceived ability to use CER after attending the session in these areas: using CER reviews, knowledge of CER methods, identifying problems with randomized controlled trials, identifying threats to validity, understanding of evidence synthesis approaches, and evaluating the quality of CER (all P values < 0.001). The questionnaire demonstrated acceptable reliability and validity evidence (limited evidence of construct under-representation and construct irrelevant variance). CONCLUSIONS: The CER educational program was effective in increasing participants' CER knowledge and self-perceived ability to evaluate relevant evidence. Improving knowledge and awareness of CER and its applicability is a critical first step in improving its use in health care decision making.