Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
1.
Acta Diabetol ; 2024 May 26.
Article in English | MEDLINE | ID: mdl-38796828

ABSTRACT

INTRODUCTION: Type 1 and type 2 diabetes mellitus (DM) are often accompanied by mild forms of pancreatic exocrine insufficiency (PEI). The prevalence rates of PEI in diabetic patients are unclear and variable depending on the testing modality and the studies published. The clinical consequences of PEI in diabetics are also not well defined. AIM: We aimed to determine the prevalence of PEI in a diabetic cohort using the faecal elastase-1 (FE-1) assay as a screening test and to validate a patient-reported symptom-based scoring system, the (PEI-S) for diagnosing PEI within this patient population. METHODS: Two hundred and three diabetic patients attending diabetic and gastroenterology outpatients of a university hospital without previously known PEI were recruited for the study. Demographic parameters, PEI score (PEI-S), and glycated hemoglobin (HBA1c) were documented in standardized data sheets, and a stool sample was obtained. A FE-1 value < 200 µg/g and or a PEIS of > 0.6 was used as the screening cut-off for PEI. RESULTS: One hundred sixty-six patients returned faecal samples. The prevalence of PEI, as measured by low FE-1, was 12%. Smoking was associated with an increased risk of developing PEI in this diabetic population. No other independent risk factors were identified. The PEI-S system did not differentiate between people with diabetes having a normal and low FE1. CONCLUSION: 12% of this mixed, real-life cohort of type 1 and 2 DM patients had undiagnosed PEI, as defined by an FE-1 score of less than 200 µg/g. While this may appear low, given the rising prevalence of type 2 DM worldwide, there is likely an unrecognized burden of PEI, which has long-term health consequences for those affected. The PEI-S, a symptom-scoring system for patients with PEI, did not perform well in this patient group.

2.
Digestion ; 95(4): 288-292, 2017.
Article in English | MEDLINE | ID: mdl-28511171

ABSTRACT

INTRODUCTION: The finding of a raised intraepithelial lymphocytes (IELs) count with normal villous architecture is of sufficient clinical importance to be reported in routine duodenal biopsies. AIM: To study the clinical and demographic data of patients with isolated increased IELs on duodenal biopsy. METHODS: A single-tertiary-centre retrospective study was carried out with a review of medical records of patients with increased IELs. Patients from 2012 to 2014, >18 years with at least one biopsy from the second part of the duodenum with increased IELs; defined as >25 IELs/100 enterocytes, with preserved villous architecture were identified from our histopathology database with exclusion of patients with coeliac disease (CD).Clinical and demographic data were recorded following a chart review. CD was diagnosed by the attending physician based on the Physician Global Assessment. Data was compared between groups using a Student t test and ORs were calculated as appropriate. Statistical significance was set a priori at p < 0.05. RESULTS: Over 24 months, 6,244 patients were found to have duodenal biopsies and 114 (1.8%) had isolated increased IELs. Of the patients with increased IELs, the mean age was 50 years and 34 (30%) were male. Follow-up was available in 75 (65%) of these and CD was subsequently diagnosed in 32% (n = 24). CD was associated with the female gender (22 out of 24 vs. 39 out of 51, OR 7.5, older age 55 vs. 41 years, p < 0.04), and higher IEL count with an IEL of >40 in 11 out of 24 (46%) with CD vs. 12 out of 51 (24%) without CD, p = 0.0006. CONCLUSION: It is a non-specific but important finding, as it can have clinical implications.


Subject(s)
Celiac Disease/immunology , Duodenum/immunology , Intraepithelial Lymphocytes , Adult , Aged , Aged, 80 and over , Biopsy , Duodenum/pathology , Female , Humans , Male , Middle Aged , Retrospective Studies , Young Adult
4.
Aliment Pharmacol Ther ; 33(12): 1261-72, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21521250

ABSTRACT

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at increased risk of osteoporosis. A number of studies have emerged in recent years indicating that tumour necrosis factor (TNF) blockade appears to have a beneficial effect on bone mineral density (BMD) in IBD patients. AIMS: To provide a review of the available data regarding the effect of the currently licensed anti-TNF-α therapies on bone metabolism and BMD in IBD patients. METHODS: A Medline search was performed using the search terms 'infliximab', 'bone metabolism', 'IBD', 'BMD', 'bone markers', 'adalimumab', 'bone disease', 'Crohn's disease' and 'ulcerative colitis'. RESULTS: Infliximab has a beneficial effect on bone turnover markers in Crohn's disease (CD) patients in the short term. The longest study to date comprising 24 CD patients showed an overall improvement in two bone formation markers - b-alkaline phosphatase (P = 0.022) and osteocalcin (P = 0.008) at 4 months post-treatment. Moreover, the largest study to date comprising 71 CD patients showed significant improvement in sCTx, a bone resorption marker (P = 0.04) at week-8 post-treatment. There is little data looking at the effect of anti-TNF-α therapy on bone metabolism in ulcerative colitis. Moreover, the long-term effects of anti-TNF-α therapy on bone structure and fracture risk in IBD patients are currently not known. The effect of cessation of anti-TNF-α therapy on bone metabolism is also unknown. CONCLUSION: Properly controlled long-term trials are needed to fully evaluate the impact of TNF blockade on bone mineral density.


Subject(s)
Adrenal Cortex Hormones/adverse effects , Antibodies, Monoclonal/therapeutic use , Bone Density/drug effects , Fractures, Bone/prevention & control , Inflammatory Bowel Diseases/drug therapy , Osteoporosis/drug therapy , Tumor Necrosis Factor-alpha/therapeutic use , Antibodies, Monoclonal/pharmacology , Female , Fractures, Bone/chemically induced , Humans , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/metabolism , Infliximab , Male , Osteoporosis/chemically induced , Tumor Necrosis Factor-alpha/pharmacology
5.
J Crohns Colitis ; 3(4): 282-6, 2009 Dec.
Article in English | MEDLINE | ID: mdl-21172288

ABSTRACT

UNLABELLED: Video capsule endoscopy is an invaluable tool for examining the small bowel. It is non-invasive and generally well tolerated, however its role in the assessment of the severity and extent of small bowel Crohn's disease has not, to date, been adequately evaluated. METHODS: All capsule endoscopies performed over a two year period in a tertiary referral centre in subjects with known or suspected Crohn's disease were reviewed. RESULTS: Twenty-six capsule endoscopy studies in total were included. These were performed in 15 cases of known Crohn's disease, 5 cases of suspected Crohn's disease, 3 cases of endoscopically diagnosed non-specific terminal ileal inflammation and finally 3 post colectomy cases of indeterminant being considered for IPAA formation. Ten patients known to have small bowel Crohn's disease were prospectively recruited; of 3 with normal small bowel follow through or CT exams, one had an abnormal capsule endoscopy. The other 7 patients had small bowel follow through or abdominal CT scans consistent with small bowel Crohn's disease; additional mucosal abnormalities were detected by capsule endoscopy in 6 cases with capsule retention in the stomach in one. Of 5 with colonic Crohn's disease normal small bowel imaging corresponded with normal capsule endoscopy in all but one. A diagnosis of Crohn's disease was made in 2 out of 5 cases of suspected Crohn's disease on the basis of the capsule endoscopy findings. Three patients with non-specific acute terminal ileal inflammation at ileocolonoscopy were confirmed to have ongoing inflammation. The capsule was retained in four subjects beyond 24 h. CONCLUSION: Capsule endoscopy more accurately determines the severity and extent of the Crohn's disease in the small bowel than traditional imaging modalities.

6.
Ann Oncol ; 19(6): 1075-81, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18238782

ABSTRACT

ADAM-17 is a matrix metalloproteinase-like enzyme involved in the release of several ligands that have been shown to promote both cancer formation and progression. These ligands include transforming growth factor-alpha, amphiregulin, heparin-binding epidermal growth factor, epiregulin and tumor necrosis factor-alpha. In this investigation, we measured the expression of total ADAM-17 by enzyme-linked immunosorbent assay in 153 invasive breast cancers. We also measured the precursor and active forms by western blotting in 140 invasive breast cancers. Expression of ADAM-17 was significantly increased in high-grade compared with low-grade tumors and was independent of tumor size, lymph node metastasis and estrogen receptor status. Patients with high expression of ADAM-17 had a significantly shorter overall survival compared with those with low expression. Significantly, the prognostic impact of ADAM-17 was independent of conventional prognostic factors for breast cancer. Our results are further evidence that ADAM-17 is involved in breast cancer progression and thus provides further impetus for exploiting ADAM-17 as new target for cancer treatment.


Subject(s)
ADAM Proteins/biosynthesis , Breast Neoplasms/enzymology , ADAM17 Protein , Breast Neoplasms/mortality , Disease Progression , Enzyme-Linked Immunosorbent Assay , Female , Humans , Middle Aged , Prognosis
7.
Ann Oncol ; 17(4): 597-604, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16403812

ABSTRACT

BACKGROUND: Survivin, a novel inhibitor of apoptosis, is one of the most cancer-specific proteins identified to date. In this study we (a) evaluated the association between survivin and HER2, vascular endothelial growth factor (VEGF) and uPA/PAI-1 expression and (b) defined its effect on clinical outcome in a large breast cancer patient cohort. PATIENTS AND METHODS: Survivin expression was measured by ELISA in primary breast cancer tissue extracts from 420 patients with long-term clinical follow-up. RESULTS: Survivin was detected in 378 (90%) of the 420 primary breast cancer cases. Increased survivin levels were significantly associated with high nuclear grade (P < 0.0001), negative hormone receptor status (P = 0.0028), HER2 overexpression (P = 0.0094), VEGF expression (P < 0.0001), high uPA (P = 0.0002) and PAI-1 levels (P = 0.0002). Using the 25th percentile (1.4 ng/mg) as a cut-off point, patients expressing elevated survivin had a significantly worse disease-free survival (DFS: P = 0.0007, RR 1.97) and overall survival (OS: P = 0.0009, RR 2.11) compared with patients expressing lower levels of survivin. In multivariate analysis, this prognostic value of survivin was independent of both traditional and novel clinicopathologic factors for both DFS (P = 0.0076, RR 1.72) and OS (P = 0.0155, RR 1.76). CONCLUSIONS: The independent prognostic relevance of survivin, when combined with previous data from model systems implicating survivin in the inhibition of apoptosis, suggests that survivin may be a suitable target for future therapeutic strategies.


Subject(s)
Breast Neoplasms/metabolism , Microtubule-Associated Proteins/metabolism , Neoplasm Proteins/metabolism , Plasminogen Activator Inhibitor 1/metabolism , Receptor, ErbB-2/metabolism , Treatment Outcome , Urokinase-Type Plasminogen Activator/metabolism , Vascular Endothelial Growth Factor A/metabolism , Cohort Studies , Female , Humans , Inhibitor of Apoptosis Proteins , Survivin
8.
Eur J Gastroenterol Hepatol ; 17(4): 463-6, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15756102

ABSTRACT

We describe a patient with chylous ascites, who was extensively investigated for the cause. No malignant or lymphatic disease could be found, but a liver biopsy revealed liver cirrhosis. The chylous ascites was unsuccessfully treated with a sodium restriction diet, diuretics and a medium chain triglyceride diet. After the placement of a transjugular intrahepatic portosystemic shunt the ascites disappeared.


Subject(s)
Chylous Ascites/surgery , Liver Cirrhosis/surgery , Portasystemic Shunt, Transjugular Intrahepatic , Aged , Chylous Ascites/etiology , Chylous Ascites/pathology , Humans , Liver/pathology , Liver Cirrhosis/complications , Liver Cirrhosis/pathology , Male , Triglycerides/analysis , Triglycerides/blood
9.
Aliment Pharmacol Ther ; 20(8): 851-7, 2004 Oct 15.
Article in English | MEDLINE | ID: mdl-15479356

ABSTRACT

BACKGROUND AND AIMS: Patients with Crohn's disease are at increased risk of osteoporosis. Disease activity and circulating proinflammatory cytokines are thought to play a role in this process. Infliximab, a chimaeric antitumour necrosis factor-alpha antibody is effective in the treatment of Crohn's disease. The aim of this study was to investigate the impact of treatment with infliximab on bone turnover in Crohn's disease patients. METHODS: This was a prospective trial. Twenty-four patients with active Crohn's disease were treated with infliximab (5 mg/kg). Bone markers were assayed pre- and post-treatment. Bone formation was measured using serum bone-specific alkaline phosphatase and total osteocalcin and bone resorption using serum N-telopeptide cross-linked type 1 collagen. RESULTS: Infliximab therapy caused a significant increase in both markers of bone formation in patients with active Crohn's disease. No significant change in the bone resorption marker serum N-telopeptide cross-linked type 1 was found. CONCLUSION: Infliximab therapy had a significant beneficial effect on bone metabolism in patients with active Crohn's disease. These findings further support the theory that active ongoing inflammation and high levels of circulating cytokines play a pivotal role in the pathogenesis of bone loss in patients with Crohn's disease.


Subject(s)
Antibodies, Monoclonal/adverse effects , Bone Remodeling/drug effects , Crohn Disease/drug therapy , Gastrointestinal Agents/adverse effects , Adult , Aged , Biomarkers/blood , Female , Humans , Infliximab , Male , Middle Aged , Prospective Studies
10.
Am J Gastroenterol ; 98(8): 1682-7, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12907319

ABSTRACT

Inflammatory bowel disease (IBD) is associated with an increased risk of developing intestinal cancer at sites of chronic inflammation. Aminosalicylates, including both sulfasalazine and mesalamine, are the most commonly prescribed anti-inflammatory agents prescribed in IBD. On balance, the body of literature to date suggests that aminosalicylates confer some protection against the development of colonic neoplasia in patients with IBD and in a variety of models, including in the noninflamed gut. This latter observation implies that aminosalicylates may be of chemopreventive value in normal as well as IBD individuals. The current review examines and gives an overview of the evidence from a variety of sources, including epidemiological, in vivo and in vitro studies that have investigated the potential anticancer effects of aminosalicylates.


Subject(s)
Aminosalicylic Acids/therapeutic use , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Anticarcinogenic Agents/therapeutic use , Colorectal Neoplasms/prevention & control , Inflammatory Bowel Diseases/drug therapy , Animals , Colorectal Neoplasms/etiology , Evaluation Studies as Topic , Humans , Inflammatory Bowel Diseases/complications
12.
Gut ; 52(3): 358-62, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12584216

ABSTRACT

BACKGROUND AND AIMS: The majority of patients with inflammatory bowel disease (IBD) have a normal life expectancy and therefore should not be weighted when applying for life assurance. There is scant literature on this topic. In this study our aim was to document and compare the incidence of difficulties in application for life and medical insurance in a population based cohort of IBD patients and matched population controls. METHODS: A population based case control study of 1126 IBD patients and 1723 controls. Based on a detailed questionnaire, the frequency and type of difficulties encountered when applying for life and medical insurance in matched IBD and control populations were appraised. RESULTS: In comparison with controls, IBD patients had an 87-fold increased risk of encountering difficulties when applying for life assurance (odds ratio (OR) 87 (95% confidence interval (CI) 31-246)), with a heavily weighted premium being the most common problem. Patients of high educational status, with continuous disease activity, and who smoked had the highest odds of encountering such problems. Medical insurance difficulties were fivefold more common in IBD patients compared with controls (OR 5.4 (95% CI 2.3-13)) although no specific disease or patient characteristics were identified as associated with such difficulties. CONCLUSIONS: This is the first detailed case control study that has investigated insurance difficulties among IBD patients. Acquiring life and medical insurance constituted a major problem for IBD patients in this study. These results are likely to be more widely representative given that most insurance companies use international guidelines for risk assessment. In view of the recent advances in therapy and promising survival data on IBD patients, evidence based guidelines for risk assessment of IBD patients by insurance companies should be drawn up to prevent possible discriminatory practices.


Subject(s)
Inflammatory Bowel Diseases/economics , Inflammatory Bowel Diseases/rehabilitation , Insurance Coverage/statistics & numerical data , Insurance Selection Bias , Insurance, Health/statistics & numerical data , Insurance, Life/statistics & numerical data , Registries , Adolescent , Adult , Case-Control Studies , Educational Status , Female , Humans , Logistic Models , Male , Middle Aged , Netherlands , Odds Ratio , Prejudice , Prognosis , Risk Factors , Smoking
13.
Gut ; 52(1): 101-8, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12477769

ABSTRACT

BACKGROUND AND AIMS: Mutant tumour derived DNA has been detected in the sera of colorectal cancer patients. We investigated if mutant serum KRAS2 was detectable preoperatively in a large group of patients with colorectal neoplasia. A prospective study of 94 patients who underwent putative curative resection for colorectal carcinoma (CRC) was performed to ascertain if serum mutant KRAS2 could be used postoperatively as a disease marker. METHODS: Preoperative sera from 78 patients were analysed (group A). Sera from 94 patients were obtained three monthly for up to three years during the postoperative period (group B). Codon 12 and 13 KRAS2 mutations were analysed in matched tumour and serum samples. RESULTS: In the preoperative group (group A), KRAS2 mutation was found in 41/78 (53%) tumours and in 32/78 (41%) preoperative sera. Of 41 tumour KRAS2 mutation positive cases, 31/41 (76%) had an identical serum mutation detectable. In group B, the postoperative follow up group, 60/94 cases were primary tumour KRAS2 mutation positive. Of these 60, 16/60 (27%) became persistently serum mutant KRAS2 positive postoperatively. Ten of 16 (63%) of these developed a recurrence compared with only 1/44 (2%) patients who remained serum mutant negative (odds ratio 71.7 (95% confidence interval 7.7-663.9; p=0.0000). None of 34 tumour mutation negative cases became serum mutant KRAS2 positive postoperatively, despite recurrence in 9/34 patients. The relative hazard of disease recurrence in postoperative serum mutant KRAS2 positive patients was 6.37 (2.26-18.0; p=0.000). CONCLUSIONS: Serum mutant KRAS2 can be detected preoperatively in all stages of colorectal neoplasia. Postoperatively, serum mutant KRAS2 is a strong predictor of disease recurrence, stronger even than Dukes' stage of disease, and thus shows potential for use in clinical practice as a marker of preclinical disease recurrence.


Subject(s)
Colorectal Neoplasms/blood , Colorectal Neoplasms/genetics , DNA, Neoplasm/blood , Neoplasm Recurrence, Local/blood , Proto-Oncogene Proteins/blood , Proto-Oncogene Proteins/genetics , Aged , Biomarkers/blood , Carcinoembryonic Antigen/blood , Colorectal Neoplasms/mortality , DNA Mutational Analysis , Epidemiologic Studies , Female , Humans , Male , Middle Aged , Prognosis , Proto-Oncogene Proteins p21(ras) , ras Proteins
14.
Eur J Clin Microbiol Infect Dis ; 21(1): 27-34, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11913498

ABSTRACT

The bactericidal activities and post-antibiotic effects of BMS-284756 (T-3811ME), levofloxacin, and ciprofloxacin were evaluated against a methicillin-susceptible and a methicillin-resistant Staphylococcus aureus strain. Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, post-antibiotic effects, and post-antibiotic sub-MIC effects were determined and time-kill studies were performed for BMS-284756, levofloxacin, and ciprofloxacin. At 4-times and 10-times the MIC, time-kill kinetics over 3 h and over 24 h were similar for all three quinolones when effects were considered as multiples of the MIC. All three quinolones achieved a 3 log10 reduction in cfu/ml within 2 h. At 10-times the MIC, the post-antibiotic effects of BMS-284756, levofloxacin, and ciprofloxacin were 1.6-2.6 h for the methicillin-susceptible Staphylococcus aureus strain and 1.5-1.9 h for the methicillin-resistant Staphylococcus aureus strain. When actual concentrations were considered, BMS-284756 achieved results comparable to levofloxacin and ciprofloxacin at concentrations nearly 10-fold less. When relating the pharmacokinetic properties of the three quinolones to their in vitro activities, the resulting Cmax/MIC and AUC/MIC ratios were. respectively, 120-240.7 and 1,321.7-2,643 for BMS-284756, 22.8 and 190 for levofloxacin, and 5.9-11.9 and 54.8-109.6 for ciprofloxacin. The greater in vitro activity and favorable human pharmacokinetics of BMS-284756 may translate to improved clinical effectiveness of this agent compared to currently marketed quinolones.


Subject(s)
Anti-Infective Agents/pharmacology , Ciprofloxacin/pharmacology , Fluoroquinolones , Indoles , Levofloxacin , Methicillin Resistance , Ofloxacin/pharmacology , Quinolones , Staphylococcus aureus/drug effects , Blood Bactericidal Activity , Drug Resistance, Microbial , Humans , Methicillin/pharmacology , Microbial Sensitivity Tests , Sensitivity and Specificity
15.
Br J Cancer ; 85(10): 1499-503, 2001 Nov 16.
Article in English | MEDLINE | ID: mdl-11720435

ABSTRACT

The incidence of oesophageal adenocarcinoma is rising; to date, no susceptibility genes have been identified. p73, a novel p53 homologue, maps to chromosome 1p36, a region commonly deleted in oesophageal cancers. p73 shares some p53-like activity, but in addition, may also play a role in gastrointestinal epithelial inflammatory responses. A non-coding p73 polymorphism (denoted AT or GC) may be functionally significant. We investigated whether this polymorphism might play a role in the aetiopathogenesis of oesophageal cancer. This was a case-control, retrospective study. 84 cases of oesophageal cancer (25 squamous and 59 adenocarcinoma) and 152 normal population controls were genotyped for this polymorphism. Informative cases were examined for p73 LOH within the tumour. AT/AT homozygotes were significantly less prevalent in the oesophageal cancer population (1/84 = 1.2%) compared to controls (15/152 = 9.9%) (P < 0.02), corresponding to an odds ratio of 0.11 (95% C.I. 0.02-0.6, P < 0.02), or 9-fold reduced risk. Moreover, AT/AT homozygotes were significantly less frequent in the cancer population than would be expected under the Hardy-Weinberg hypothesis (P = 0.0099). LOH at the p73 locus was observed in 37.8% (14/37) of the AT/GC heterozygotes studied; in all cases there was loss of the AT allele. Our findings indicate that p73 AT/AT homozygotes appear to be protected against the development of oesophageal cancer. Clinically, this observation could have implications in aiding identification of high-risk Barrett's oesophagus patients.


Subject(s)
Carcinoma/genetics , DNA-Binding Proteins/genetics , Esophageal Neoplasms/genetics , Genetic Predisposition to Disease , Nuclear Proteins/genetics , Polymorphism, Genetic , Adenocarcinoma/epidemiology , Adenocarcinoma/genetics , Adult , Aged , Carcinoma/epidemiology , Carcinoma, Squamous Cell/epidemiology , Carcinoma, Squamous Cell/genetics , Case-Control Studies , Esophageal Neoplasms/epidemiology , Female , Gene Frequency , Genes, Tumor Suppressor , Genotype , Humans , Incidence , Loss of Heterozygosity , Male , Middle Aged , Retrospective Studies , Tumor Protein p73 , Tumor Suppressor Proteins
16.
J Lab Clin Med ; 138(3): 164-76, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11528369

ABSTRACT

The purpose of this review is to outline the principal mechanisms involved in folate metabolism and how they may relate to the pathogenesis of colorectal cancer (CRC). In recent years, mild folate depletion (low normal level) has been associated with an increased risk of developing certain cancers, in particular colorectal neoplasia. The epidemiologic and mechanistic evidence linking folate deficiency with carcinogenesis is reviewed, with a particular emphasis on colorectal neoplasia. Methylenetetrahydrofolate reductase (MTHFR) is a critical folate metabolizing enzyme, and a functional polymorphic variant of this enzyme, the so-called thermolabile variant, caused by a C677T transition in the MTHFR gene, is common in the general population. This review critically examines the evidence that suggests that carriers of this C677T variant may be at increased risk of developing colorectal neoplasia. Although folate depletion may predispose to the initiation of the neoplastic process, folate supplementation, on the other hand, might potentiate the progression of an already established early neoplastic clone (eg, a colorectal adenoma). This could have potential public health implications, given an increasingly widespread policy of folate supplementation of food staples.


Subject(s)
Adenoma/metabolism , Colorectal Neoplasms/metabolism , Folic Acid/metabolism , Vitamin B 12/metabolism , Adenoma/genetics , Adenoma/pathology , Animals , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , DNA Methylation , DNA, Neoplasm/biosynthesis , Dietary Supplements/adverse effects , Folic Acid/administration & dosage , Folic Acid Deficiency/metabolism , Humans , Methylenetetrahydrofolate Reductase (NADPH2) , Oxidoreductases Acting on CH-NH Group Donors/genetics , Oxidoreductases Acting on CH-NH Group Donors/metabolism
17.
Int J Toxicol ; 20(3): 121-42, 2001.
Article in English | MEDLINE | ID: mdl-11488554

ABSTRACT

This study evaluated the potential reproductive toxicity of phenol in a rat two-generation reproduction study, which included additional study endpoints, such as sperm count and motility, developmental landmarks, histological evaluation of suspect target organs (liver, kidneys, spleen, and thymus), weanling reproductive organ weights, and an immunotoxicity screening plaque assay. Phenol was administered to 30 Sprague-Dawley rats/sex/group in the drinking water at concentrations of 0, 200, 1000, or 5000 ppm. Parental (P1) animals were treated for 10 weeks prior to mating, during mating, gestation, lactation, and until sacrifice. The F1 generation (P1 offspring) was treated using a similar regimen, while the F2 generation was not treated. After mating, 10 P1 males/group were evaluated using standard clinical pathology parameters and an immunotoxicity screening plaque assay. Significant reductions in water and food consumption were observed in the 5000-ppm group in both generations; corollary reductions in body weight/body weight gain were also observed. Mating performance and fertility in both generations were similar to controls, and no adverse effects on vaginal cytology or male reproductive function were observed. Vaginal opening and preputial separation were delayed in the 5000-ppm group, and were considered to be secondary to the reduction in F1 body weight. Litter survival of both generations was reduced in the 5000-ppm group. Absolute uterus and prostate weights were decreased in the F1 generation at all dose levels; however, no underlying pathology was observed and there was no functional deficit in reproductive performance. Therefore, these findings were not considered to be adverse. No evidence of immunotoxicity was noted in the 5000-ppm group. The effects noted at the high concentration were presumed to be associated with flavor aversion to phenol in the drinking water. Based on a comprehensive examination of all parameters, the no-observable-adverse-effect level (NOAEL) for reproductive toxicity of phenol administered in drinking water to rats is 1000 ppm. The corresponding daily intake of phenol for an adult rat at the NOAEL of 1000 ppm is equivalent to about 70 mg/kg/day for males and 93 mg/kg/day for females.


Subject(s)
Disinfectants/toxicity , Genitalia/abnormalities , Phenol/toxicity , Prenatal Exposure Delayed Effects , Reproduction/drug effects , Administration, Oral , Animals , Body Weight , Disinfectants/administration & dosage , Eating/drug effects , Female , Male , No-Observed-Adverse-Effect Level , Phenol/administration & dosage , Pregnancy , Rats , Rats, Sprague-Dawley , Water Supply
19.
Expert Opin Investig Drugs ; 10(8): 1409-22, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11772259

ABSTRACT

Efflux is the process in which bacteria transport compounds outside the cell which are potentially toxic, such as drugs or chemicals or compounds. Efflux pumps can be identified not only by biochemical, microbiological, or molecular means but with the availability of microbial genomic sequences, by the application of bioinformatics analysis of DNA sequences for key conserved structure motifs. Efflux has been identified as a relevant contributor to bacterial resistance in the clinic and is now recognised as one of the most important causes of intrinsic antibiotic resistance in bacteria, especially in Pseudomonas aeruginosa. With the recognition of efflux as a major factor in bacterial resistance, several companies have invested in the identification and development of bacterial efflux pump inhibitors. Among those, Microcide, Pfizer, Paratek and several academic laboratories are in the process of exploring efflux pump inhibitors from synthetic, natural products and peptidomimetics. Inhibiting bacterial efflux with a non-antibiotic inhibitor would restore activity of an antibiotic subject to efflux (similar to the use of beta-lactamase inhibitors to combat beta-lactamase production by bacteria). The feasibility of such an approach has been experimentally demonstrated in vitro and in vivo for efflux reversal of levofloxacin.


Subject(s)
Bacteria/metabolism , Bacterial Toxins/metabolism , Bacteria/drug effects , Biological Transport, Active/drug effects , Drug Resistance
20.
Int J Gastrointest Cancer ; 30(3): 105-11, 2001.
Article in English | MEDLINE | ID: mdl-12540022

ABSTRACT

BACKGROUND AND AIM: Folate deficiency predisposes to sporadic colorectal cancer (CRC). Methylenetetrahydrofolate reductase (MTHFR) is a critical folate-metabolising enzyme and a polymorphism at position 677 (C677T), is associated with reduced enzyme activity. We investigated whether this functional polymorphism modulates the risk of developing CRC. METHODS: This was a retrospective case-control study. 136 unselected cases of sporadic CRC and 848 normal population controls were genotyped for the MTHFR C677T polymorphism. Tumor tissue was genotyped to assess loss of heterozygosity (LOH). RESULTS: MTHFR CT heterozygotes had a significantly increased risk of developing CRC (53.7% of CRC cases vs 38.4% of controls), odds ratio 1.86 (95% CI 1.3-2.7, p < 0.005). No increased cancer risk was observed in TT homozygotes. The MTHFR 'T' allele frequency was significantly higher in the cancer group (0.3713) as compared to controls (0.2900, p < 0.008). LOH at the MTHFR locus was observed in 18% of informative cancers, with exclusive loss of the variant 'T' allele, in all cases. CONCLUSION: In this study of a homogenous northern European population, MTHFR CT heterozygotes had an almost two-fold increased risk of developing sporadic CRC. The exclusive pattern of MTHFR allele loss in cases of LOH, suggest that functional MTHFR activity within a tumor might play an important role in the survival and progression of a colonic neoplasm.


Subject(s)
Adenocarcinoma/genetics , Colorectal Neoplasms/genetics , Oxidoreductases Acting on CH-NH Group Donors/genetics , Adenocarcinoma/enzymology , Case-Control Studies , Colorectal Neoplasms/enzymology , Disease Progression , Humans , Loss of Heterozygosity , Methylenetetrahydrofolate Reductase (NADPH2) , Polymorphism, Genetic/genetics , Retrospective Studies , Risk Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...