Glutathione S -transferase T1 polymorphisms are associated with outcome in colorectal cancer

Colorectal cancer (CRC) remains a significant cause of mortality accounting for approximately 10% of all deaths from malignancy in the western world. Polymorphism in the glutathione S-transferase GSTT1 gene has been associated with CRC risk in some but not all studies. In this study, we examined associations between GSTT1 genotypes and CRC risk, and prognosis in 361 cases and 881 unrelated controls. GSTT1 null was associated with a small but significant increase in risk (P = 0.0006, odds ratio (OR) = 1.65, 95% confidence interval (CI) = 1.22-2.24). GSTT1 null was also associated with a significantly younger age at diagnosis (mean 65.2 years) compared with GSTT1 A (mean 67.6 years, P = 0.031). There were no significant associations between GSTT1 genotypes and clinical factors (e.g. Dukes stage, differentiation and tumour node metastasis classification) in the total case group. However, following stratification by age (<70 versus > or =70 years at diagnosis), in the patients diagnosed <70 years of age, GSTT1 null was more common in Dukes grade A/B tumours (P = 0.046), stage T1/T2 tumours (P = 0.053) and those with a pushing margin (P = 0.066). We also identified associations between GSTT1 null and increased prevalence of host lymphocyte response, particularly in the younger patients (P = 0.036). Furthermore, GSTT1 null was associated with improved survival in younger patients (P = 0.017, hazards ratio (HR) = 0.52, 95% CI = 0.31-0.89) but poorer survival in older patients (P = 0.017, HR = 1.89, 95% CI = 1.12-3.20). We proposed a model based on the dual functionality of GSTT1 to explain these contrasting results. We suggest that the null genotype is associated with improved immune response in younger patients, but poorer detoxification in older patients. These findings may also provide an explanation for the contrasting finding of other studies on the role of this gene in CRC.

A phase II study of G17DT in gastric carcinoma

PURPOSE

G17DT is a gastrin immunogen, raising antibodies that blockade gastrin-stimulated growth. The aim of the study was to characterise antibody response and assess safety and tolerability of G17DT given to patients with gastric cancer.

EXPERIMENTAL DESIGN

G17DT was administered to 52 patients with gastric adenocarcinoma at weeks 0, 2 and 6 by intramuscular injection at doses of 10, 100 and 250 microg. Antibody levels were measured by an ELISA assay. A radioligand displacement assay determined the ability of G17DT-immunised patients' sera to inhibit binding of 125IG17 to cholecystokinin (CCK)-2 receptors.

RESULTS

By week 12 of the study, 6/12 evaluable stage I-III patients achieved an antibody response in the 10 microg group, 7/11 in the 100 microg group, and 11/12 in the 250 microg group. Stage IV patients dosed at 250 microg achieved a similar response rate to stage I-III patients dosed at 10 or 100 microg. G17DT was well tolerated in 47/52 patients. Two patients suffered significant adverse reactions including injection site pain and abscess. G17DT antibodies displaced iodinated gastrin from CCK-2 receptors, with the level of displacement correlating with antibody titre.

CONCLUSIONS

G17DT immunisation is a well-tolerated method of raising functional antibodies to 17 amino acid gastrin forms in patients with gastric carcinomas.

Subcellular localisation of cyclin D1 protein in colorectal tumours is associated with p21(WAF1/CIP1) expression and correlates with patient survival

We investigated the expression of the cell cycle regulatory proteins cyclin D1 and p21(WAF1/CIP1) (p21) in human colorectal carcinomas using immunohistochemistry. Cyclin D1 was not detected in normal colonic epithelium; however, expression was observed in 74/126 (58.7%) of the tumour samples studied. Protein was detected in the nucleus in 22/126 (17.4%) and exclusively in the cytoplasm in 52/126 (41.3%) tumours. Nuclear expression of cyclin D1 was associated with poorly differentiated tumours (p = 0.035) and was more common in right- than in left-sided tumours (p = 0.005). Tumours displaying either, expression of cytoplasmic, (p = 0.05, HR 0.56, 95% CI 0.31-1.0) or nuclear (p = 0.021, HR 0.24, 95% CI 0.07-0.81) cyclin D1 were associated with improved patient survival compared with tumours negative for cyclin D1. p21 protein was strongly expressed mainly in the upper crypts of normal colonic epithelial cells, but in 63/126 (50%) of the tumour samples studied p21 expression was absent. Patients with tumours in which >50% of cells expressed p21 had improved survival compared to patients whose tumours were negative or had < or =50% of cells expressing p21 (p = 0.06, HR 0.33, 95% CI 0.1-1.0). We also observed a significant association between cyclin D1 subcellular localisation and p21 expression: 21/22 (95.5%) tumours expressing cyclin D1 in the nucleus also expressed p21, whereas only 17/52 (32.7%) of the tumours displaying exclusive cytoplasmic cyclin D1 staining were positive for p21 (p < 0.001). These data highlight the significance of exclusive cytoplasmic expression of cyclin D1 in colorectal cancer and lend support to recent in vitro studies suggesting that p21 protein may modulate the subcellular localisation of the cyclin D1 protein. Thus, deregulated expression of the cyclin D1 and p21 proteins are important in colorectal tumourigenesis and have implications for patient prognosis.

Promoting sun safety among zoo visitors

BACKGROUND

Each year, millions of children visit zoological parks, where they are exposed to long bouts of ultraviolet radiation (UVR). We conducted a study in the winter and replicated it in the summer to evaluate an intervention for reducing UVR exposure during the zoo visit.

METHODS

Each study used a nonequivalent control group design: one zoological site received the intervention and a second received evaluation only. Key outcome measures consisted of observed prevalence of hat use by exiting children (N = 8,721 and 8,524, respectively, in winter and summer studies) and purchase rates of sunscreen and hats in zoo gift shops. Intervention consisted of tip sheets for parents, children's activities, prompts, and discounts off the price of sunscreen and sun-protective hats.

RESULTS

In the summer study, sales of both sunscreen and target hats increased significantly at the intervention site relative to the control site, whereas in the winter study, only sunscreen sales at the intervention site had a significant (relative) increase. Children's hat use increased significantly at the intervention site, but only in the winter study.

CONCLUSIONS

The multicomponent program was effective in promoting purchases of sun-safe items, but its impact on children's hat use was inconclusive.

Epidermal growth factor receptor structure, regulation, mitogenic signalling and effects of activation

The biological effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are mediated by an interaction with a specific cell surface receptor having both intra- and extracellular domains. The structure of the intracellular domain can be closely aligned with retroviral protein tyrosine kinases. Upon ligand-binding there is a change in conformation of the extracellular domain, the receptor being converted to dimeric. Dimeric receptor has a higher rate of catalysis than monomeric and rapidly becomes phosphorylated. This form of the receptor now associates with and phosphorylates enzymes such as phospholipase-C, altering their catalytic activity and subcellular distribution This system appears to stimulate the effects of epidermal growth factor receptor(EGFr) activation, notably proliferation, morphology, paracrine effects and differentation.

[Analysis of the publicity campaign of the tobacco brand Fortuna in 1999-2000]

The majority of tobacco advertisement in Spain is directed at youth. This advertisement, carried out on several fronts, is particularly effective with young people. In the present work we analyze different advertising efforts involved in the ad campaign carried out by Fortuna-brand (a product of the company Tabacalera S.A., and sector leader of sales in Spain) in 1999 and 2000. In terms of their marketing strategy, we can conclude that Fortuna's principal commercial objective is presenting tobacco as intrinsically associated with being young. Both the indirect promotion of its products through activities and its commercials, are aimed towards developing the image that tobacco symbolizes the series of core values more appreciated by youth. Relevant legislation will have to be adapted to this reality in order to control specifically the manner in which publicity such as that promoted by Fortuna is directed to the population.

Exposure to immunization media messages among African American parents

BACKGROUND

African Americans have low immunization rates, yet little is known about their immunization knowledge, attitudes, and practices or about the effect of outreach to this audience. In Spring 1997, the California Department of Health Services (CDHS) launched a statewide culturally sensitive and ethnically specific media campaign directed toward African Americans. This campaign was preceded by a major Los Angeles County Department of Health Services media campaign.

OBJECTIVES

The objectives of this study were to (a) estimate exposure to immunization media messages among African Americans; (b) determine sources of immunization information; and (c) assess various immunization attitudes and beliefs in order to refine future outreach efforts.

METHODS

Following the CDHS media campaign, a random digit dial survey was conducted with 801 African American families with children under age 10. The sample was drawn from the four California regions with the highest African American birth rates. It included all zip codes in these regions with greater than 150 African American births per year. Lower bound response rates ranged from 62.5 to 76.1%. Higher income and education levels were overrepresented. Results were weighted to adjust for this.

RESULTS

Over 88% remembered seeing or hearing some form of immunization information. Exposure to television ads was reported by 63% followed by billboards (51%) and radio (42%). Sixty-two percent thought mild disease was possible after shots; 27% feared HIV from needles and 19% thought pain was a barrier. Respondents who cited money as a barrier (26%) were less likely to believe that shots were available for free (P = 0.02).

CONCLUSIONS

Media advertising is an effective tool for reaching African Americans. Addressing specific concerns (e.g., clarification of the circumstances and likelihood of getting a mild case of the disease following an immunization, availability of free shots, and risk of HIV) may contribute to increased immunization rates for this population.

[Legal framework and strategy of the tobacco industry in relation to tobacco advertising in Spain]

Publicity is legally regulated in Spain, in order to avoid its misuse. Tobacco publicity is also under those regulation, having had the companies operating in this sector to adapt themselves through new strategies. In this work, the legal restrictions existing in Spain regarding publicity are analyzed, together with some of the strategies developed by tobacco companies in order to elude them. In this sense, and despite of the existing legal framework, it should be noticed that tobacco companies are cleverly taking advantage of the existence of legal loopholes in tobacco publicity to promote their products.

A pilot study investigating the role of NAT1 and NAT2 polymorphisms in gastric adenocarcinoma

In humans, aromatic and heterocyclic amine carcinogens may be acetylated by the expression products of either of the N-acetyltransferase genes, NAT1 or NAT2. This conjugation reaction can result in either activation or detoxication of these carcinogens depending on the tissue involved. Recent studies suggest that polymorphisms in NAT1 or NAT2 may modulate cancer risk. To determine if genetic differences in NAT1 and NAT2 could alter risk of gastric cancer, we tested for the presence of polymorphic N-acetyltransferase alleles (both NAT1 and NAT2) in a preliminary study of 94 gastric adenocarcinoma patients and 112 control subjects from North Staffordshire, England. We used established PCR protocols to genotype for NAT2 and NAT1 alleles (NAT2*4, NAT2*5, NAT2*6, NAT2*7, NAT2*14; NAT1*3, NAT1* 4, NAT1*10, and NAT1*11), and implemented an oligonucleotide ligation assay (OLA) to test for low-activity NAT1 alleles [NAT1*14 (G560A), NAT1*15 (C559T), and NAT1*17 (C190T)]. No significant increased risk was observed for NAT2 acetylation genotypes. However, among all cases, we found that individuals inheriting a variant NAT1 allele, NAT1*10, have a significantly elevated risk for gastric cancer (OR = 2.2, 95% CI 1. 2-3.9, P < 0.01). Interestingly, the risk observed for NAT1*10 appears to be solely associated with advanced-stage tumors (OR = 4.8, P < 0.001), suggesting a possible role in progression to advanced disease. This preliminary finding needs confirmation in a larger, detailed epidemiological study.

Blood perfusion of subcutaneous tumours in mice following the application of low-level direct electric current

Electrotherapy with low-level direct electric current has been proved to be an effective local treatment of solid tumours. In the presented study an attempt was made to evaluate the effect of a single treatment with electrotherapy on blood perfusion of solid subcutaneous fibrosarcoma Sa-1 tumours in A/J mice. The tissue-staining method with Patent blue-violet dye, the rubidium extraction technique, and the noninvasive near-infrared spectroscopy method were used for this purpose. Results of all methods indicate that perfusion and subsequently oxygenation of tumours were reduced due to application of electrotherapy.

Alterations in classical cadherins associated with progression in ulcerative and Crohn's colitis

Human colitis is a condition associated with a spectrum of altered morphologic changes and cellular adhesion. The role of cadherins, which are powerful morphoregulatory cell adhesion molecules, in colitis is provocative and as yet unknown. Herein, we present results that suggest a strong correlation between the deregulation of two cadherin molecules, E- and P-cadherins, and the progression of human colitis. We examined the expression and structural integrity of E- and P-cadherins in inflamed, dysplastic, or neoplastic human ulcerative colitis (UC) (n=58), human Crohn's colitis (n = 30), and normal tissue (n = 20) to assess cadherin function in normal and abnormal epithelium. E-cadherin is strongly expressed in normal colorectal epithelium, whereas in left-sided UC it is either down-regulated or has a single-base pair mutation in exon 4 resulting in an amino acid alteration (6 of 58 UC cases). By contrast, P-cadherin is dramatically up-regulated in both Crohn's disease and ulcerative colitis and especially in dysplastic ulcerative tissue. In vitro transfected SW-480 colorectal cells containing E-cadherin mutations identical to those in vivo were associated with increased spontaneous disaggregation compared with cells transfected with wild-type E-cadherin. Based on this evidence, we hypothesize that a small subset of colorectal cells expressing mutant E-cadherin are associated with widespread ulceration, whereas those expressing P-cadherin are associated with a rapidly dividing immature phenotype that includes dysplasia. The differential expression of mutated and wild-type cadherins examined herein are associated with a broad spectrum of abnormal epithelial phenotypes, lymphocyte integrin binding, and resistance to denudation, as is seen in the colitis adenocarcinoma sequence.

Retroviral-mediated expression of FIV envelope/Rev induces CD8+ CTL responses in mice

Recombinant retroviral vectors that express the Env and Rev proteins of feline immunodeficiency virus (FIV) were prepared and analyzed in a mouse model system for their ability to induce antigen-specific CD8+ CTL (cytotoxic T lymphocyte) responses. The ultimate goal of these studies is to develop effective immunogens for CTL induction in the cat. Recombinant Env/Rev retroviral vectors were used to transduce mouse fibroblasts and these cells were then inoculated intraperitoneally into syngeneic BALB/c mice. FIV Env-specific CTL responses were obtained. The potent ability of recombinant retroviral vector-transduced cells to elicit cell-mediated immunity in the mouse model offers the possibility that such delivery systems may serve as therapeutic and/or prophylactic treatments against FIV infection in the cat.

Heparin-binding ligands mediate autocrine epidermal growth factor receptor activation In skin organ culture

Exogenous EGF and TGF-alpha accelerate wound healing, but treatment effects are often modest. Using short-term human skin organ culture, we found that autocrine EGF receptor activation could account for this observation. Amphiregulin and heparin-binding EGF-like growth factor (HB-EGF) transcripts were rapidly and markedly induced, whereas EGF and TGF-alpha mRNAs were undetectable or only slightly increased. Vascular permeability factor and keratin 6 transcripts were also strongly induced, albeit with a >/= 3 h delay relative to HB-EGF and amphiregulin. All four transcripts were upregulated in actual healing skin wounds, HB-EGF and keratin 6 being the most prominent. The highly EGF receptor-specific tyrosine kinase inhibitor PD153035 strongly inhibited induction of all four transcripts in organ culture, as well as release of immunoreactive HB-EGF into the medium. These effects were confirmed using the anti-EGF receptor mAb 225 IgG. Neither PD153035 nor 225 IgG was toxic to keratinocytes, as judged by calcein-AM uptake. PD153035 completely abrogated the proliferative phase of keratinocyte outgrowth in skin explant cultures, whereas it had no effect on the antecedent migratory phase. Based on these results, we conclude that EGF receptor activation by highly inducible, keratinocyte-derived heparin-binding ligands is an important mechanism for amplification and transmission of the cutaneous wound healing signal.

The effects of the Child and Adolescent Trial for Cardiovascular Health upon psychosocial determinants of diet and physical activity behavior

BACKGROUND

The Child and Adolescent Trial for Cardiovascular Health is a multisite study of a school-based intervention to reduce or prevent the development of risk factors for cardiovascular disease. The purpose of this paper is to present the evaluation results of the 3-year intervention, focusing upon the psychosocial variables conceptualized as determinants of dietary and physical activity behaviors.

METHODS

A total of 96 schools across four study sites (California, Louisiana, Minnesota, and Texas) were randomized to two treatment conditions: intervention and control. Pre- and postmeasurements on the health behavior questionnaire were collected from over 6,000 students. The data analyses utilized a nested design approach in which schools served as the primary unit of analysis. Repeated-measures multivariate analyses were applied to investigate effect sizes for each determinant and to explore theoretical relationships among the determinants over time.

RESULTS

The findings indicated sustained significant effects in improved knowledge, intentions, self-efficacy, usual behavior, and perceived social reinforcement for healthy food choices (P < 0.0001 for these five variables) after 3 years. Intermittent effects were observed for perceived support and self-efficacy for physical activity. No gender by determinant interaction effects were observed, and girls reported significantly greater perceived reinforcement for healthy eating than did boys.

CONCLUSION

The CATCH program was effective in changing the psychosocial variables likely to influence a reduction in behavior for cardiovascular disease. The study is significant in that it demonstrates the viability and effectiveness of a sustained multifaceted intervention in a preadolescent population. The results point to a need for greater understanding of adolescent developmental issues and the role of community environment (particularly social support) in creating effective curricula.

Glutathione S-transferase GSTT1 genotypes and susceptibility to cancer: studies of interactions with GSTM1 in lung, oral, gastric and colorectal cancers

Allelism in glutathione S-transferase GSTM1 and GSTT1 has been suggested as a risk factor in various cancers. Accordingly, we describe a group of case-control studies carried out to identify associations between GSTT1 genotypes and susceptibility to lung, oral, gastric and colorectal cancers. The frequencies of the putatively high risk GSTT1 null genotype were not increased in the lung, oral or gastric cancer cases compared with controls but the frequency of this genotype was significantly increased (P = 0.0011, odds ratio = 1.88) in the colorectal cancer cases. No significant interactions between the GSTT1 and GSTM1 null genotypes types were identified in the cancer groups studied. Indeed, no significant associations between GSTM1 genotypes and susceptibility were identified though further evidence was obtained that the protective effect of GSTM1*A and GSTM1*B is not equal. The data complement studies showing that GSTT1 null is associated with an increased susceptibility to total ulcerative colitis and suggests that this enzyme is important in the detoxification of unidentified xenobiotics in the large intestine.

Helicobacter pylori gastritis and serum pepsinogen levels in a healthy population: development of a biomarker strategy for gastric atrophy in high risk groups

This study aimed to estimate the prevalence and type of chronic gastritis in an asymptomatic working population and to determine whether a combination of serum pepsinogen levels and Helicobacter pylori serology could be used to identify a subgroup with atrophic gastritis at elevated risk of gastric carcinoma. A 10% subsample of 544 male volunteer factory workers aged 18-63 years and participating in a larger study underwent endoscopy and biopsy. Of these men, 29 were seropositive for Helicobacter pylori; all but three (89.7%) had chronic gastritis. Serum pepsinogen A levels increased with progression from a corpus predominant pattern of gastritis through pangastritis to an antral predominant pattern. Nine subjects had corpus atrophy, which was in most cases accompanied by fasting hypochlorhydria and hypergastrinaemia. A combination of pepsinogen A below 80 ng ml-1 and Helicobaceter pylori seropositivity detected corpus atrophy with sensitivity 88.9% and specificity 92.3%. A second screening stage, using a pepsinogen A/C ratio of below 2.5 as a cut-off, resulted in a reduction in numbers requiring further investigation but with some loss of sensitivity (77.8%). Application of this two-stage screening programme to the original sample of 544 workers would have resulted in 11 (2.2%) men being selected for follow-up, excluding 25 (5.1%) false negatives. Our results suggest that a combination of serum pepsinogen levels and Helicobacter pylori serology could be useful as a biomarker strategy for detection of individuals at increased risk of gastric carcinoma and for non-invasive investigation of the natural history of Helicobacter pylori gastritis.

A histopathological comparison of the uvula between snorers and non-snorers

Snoring is a very common problem but there are few publications on the histological findings of the soft palate/uvula and these lack consistency. The relative proportions of tissue types in the base of the uvula removed from 17 adults who underwent uvulopalatopharyngoplasty for heavy snoring were therefore compared with 14 cadaveric specimens. The mean percentage of muscle from the snoring group was 12.1% compared with 7.2% in the control group (P < 0.05). The percentage of fibrous tissue was greater in the cadavers (52.8% vs 45.5% in the snorers, P < 0.05). The percentage of muscle was inversely related to the percentage of fibrous tissue in the snoring group (P < 0.02). We hypothesize that these changes are a consequence of the repetitive forces on the soft palate during snoring rather than being related to the pathogenesis of snoring.