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1.
Gastrointest Endosc ; 2021 Jan 25.
Article in English | MEDLINE | ID: mdl-33508302

ABSTRACT

BACKGROUND/AIMS: Pancreatic cystic fluid (PCF) analysis is useful to distinguish between different cyst types and guide management. The aim of our study was to compare the diagnostic accuracy of glucose level with carcinoembryonic antigen (CEA) in PCF for mucinous cyst diagnosis. METHODS: We identified studies with PCF obtained by EUS before surgery, with cysts classified as mucinous and nonmucinous according to surgical specimens. A random effects model was used for quantitative meta-analysis. Pooled sensitivities, specificities, and summary receiver operating characteristic (SROC) curve analysis were conducted. RESULTS: For CEA, we included 31 studies with 5268 patients, of which 2083 were referred for surgery and for glucose we included 5 studies with 460 patients, of which 275 were referred for surgery. Glucose performed better than CEA for mucinous cysts diagnosis (premalignant and malignant) with sensitivities of 0.91 (95% CI, 0.86-0.94) and 0.67 (95% CI, 0.65-0.70), specificities of 0.75 (95% CI, 0.68-0.82) and 0.80 (95% CI, 0.76-0.83), and areas under the ROC curve (AUC) of 0.95 and 0.79, respectively. Glucose had a higher sensitivity (91%), with uncommon false negative results, making it an excellent biomarker to exclude a mucinous cyst. Sensitivity analysis demonstrated that the findings of the current meta-analysis are robust. CONCLUSION: Glucose level in PCF is more accurate than CEA for preoperative diagnosis of mucinous cysts. It may become a useful first line test, particularly in small cysts with limited volume of PCF. Larger studies are awaited to confirm glucose as the single test for mucinous cyst diagnosis.

2.
Ecotoxicol Environ Saf ; 140: 103-108, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28254719

ABSTRACT

Nanomaterials (NM) exhibit unique properties due their size and relative area, but the mechanisms and effects in the living organisms are yet to be unfold in their totality. Potential toxicity mechanisms concerning NM as carbon nanotubes include oxidative stress generation. Several fluorimetric and colorimetric methods have been systematically used to measure NM toxicity, and controversial results have been reported. One of the problems can be related to the interference effects induced by NM, leading to artifacts that can lead to misleading conclusions. In present study, it was performed in vitro assays with two aquatic species: the zebrafish Danio rerio and the polychaete Laeonereis acuta to evaluate the potential interference capacity of single-wall carbon nanotubes (SWCNT) in a fluorometric method (TBARS assay) to measure lipid peroxidation. Obtained results indicated that gills and brain of zebrafish presented a lowered fluorescence only at extremely high concentrations (50 and 500mg/L). Determinations in anterior, middle, and posterior body regions of L. acuta showed a quite different pattern: high fluorescence at low SWCNT concentrations (0.5mg/L) and lowering at the highest (500mg/L). To eliminate matrix effect of biological samples, tests employing the standard for TBARS assay, 1,3,3-tetramethoxipropane, were run and the results showed again higher fluorescence values at low concentrations (0.5-5mg SWCNT/L), a technique artifact that could lead to misleading conclusions since higher fluorescence values implicate higher TBARS concentration, implying oxidative stress. Using the colorimetric FOX assay with cumene hydroperoxide as standard presented remarkable better results since no artifacts were observed in the same SWCNT concentration range that employed with the TBARS technique.


Subject(s)
Aquatic Organisms/drug effects , Artifacts , Lipid Peroxidation/drug effects , Nanotubes, Carbon/toxicity , Thiobarbituric Acid Reactive Substances/analysis , Water Pollutants, Chemical/toxicity , Animals , Aquatic Organisms/metabolism , Brain/drug effects , Brain/metabolism , Dose-Response Relationship, Drug , Fluorometry , Gills/drug effects , Gills/metabolism , Oxidative Stress/drug effects , Particle Size , Polychaeta/drug effects , Polychaeta/metabolism , Spectrum Analysis, Raman , Surface Properties , Zebrafish/metabolism
3.
Br J Dermatol ; 172(2): 513-21, 2015 Feb.
Article in English | MEDLINE | ID: mdl-24935194

ABSTRACT

The development of high-grade lymphoma in patients with chronic lymphocytic leukaemia is known as Richter syndrome (RS) and is associated with a grave prognosis, with a mean survival of 8 months despite treatment. Cutaneous RS has been described in a handful of cases and may be associated with a better outcome than the more common extracutaneous variants. We review the literature with particular emphasis on pathogenesis, treatment and survival of RS. We postulate that the absence of B symptoms and a normal lactate dehydrogenase level, presumably reflecting localized or limited disease, and a lower tumour burden, may explain the apparently better survival in some patients with cutaneous RS than with extracutaneous variants.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Skin Neoplasms/drug therapy , Aged , Antibodies, Monoclonal, Murine-Derived/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Female , Humans , Male , Prednisone/administration & dosage , Rituximab , Syndrome , Treatment Outcome , Vincristine/administration & dosage
4.
Pharmacoepidemiol Drug Saf ; 19(5): 499-510, 2010 May.
Article in English | MEDLINE | ID: mdl-20306455

ABSTRACT

PURPOSE: To estimate inflammatory bowel disease (IBD) prevalence in Portugal from 2003 to 2007, and to obtain disease, sex and age specific estimates. METHODS: A pharmaco-epidemiological approach based on intestinal anti-inflammatory (IAI) drugs consumption was used. Proportion of patients taking IAI drugs and mean prescribed daily dose (PDD) were estimated from a sample of 513 IBD patients. Assumptions were made about unknown parameters and sensitivity analysis performed: drug compliance (80% in base case; range 70-85%) and proportion of sulphasalazine used in IBD (52%; range 40-80%). Sex and age specific estimates were based on a proposed methodological extension and results from a nationwide (n = 5893) cross-sectional study. RESULTS: IBD prevalence increased from 86 patients per 100 000 in 2003 to 146 in 2007. Regions more affected were Lisboa and Porto (173 and 163 per 100 000 in 2007, respectively). Prevalence increased from 42 and 43 per 100 000 in 2003 to 71 and 73 in 2007, respectively for ulcerative colitis (UC) and Crohn's disease (CD). In 2007, prevalence was higher in the 40-64 age stratum for UC (99 per 100 000) and in the 17-39 stratum for CD (121). Prevalence was consistently higher in females. CONCLUSIONS: Portugal is half way between countries with the highest and lowest IBD prevalence, but is steeply making the road to the highest-level group. Despite limitations of the proposed methods, assumptions were reasonable and estimates seem to be valid. Feasibility and comparability of this methodology makes it an interesting tool for future studies on IBD epidemiology.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Gastrointestinal Agents/adverse effects , Inflammatory Bowel Diseases/epidemiology , Pharmacoepidemiology/methods , Adult , Age Factors , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Cross-Sectional Studies , Female , Gastrointestinal Agents/administration & dosage , Gastrointestinal Agents/therapeutic use , Humans , Male , Mesalamine/administration & dosage , Mesalamine/adverse effects , Mesalamine/therapeutic use , Patient Compliance/statistics & numerical data , Pharmacoepidemiology/statistics & numerical data , Portugal/epidemiology , Prevalence , Sex Factors , Sulfasalazine/administration & dosage , Sulfasalazine/adverse effects , Sulfasalazine/therapeutic use
5.
Clin Exp Dermatol ; 35(6): 627-30, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20184614

ABSTRACT

A 57-year-old man presented with a 2-year history of bilateral erosive lesions on the inguinal region, and erythematous, brown and crusted papules over the trunk. Histological examination of one lesion in conjunction with immunohistochemical study and electron microscopy led to the diagnosis of Langerhans' cell histiocytosis. After a thorough examination, the only associated findings were retroperitoneal fibrosis and hypergonadotrophic hypogonadism with a granulomatous testicular infiltrate. The patient was treated with oral acitretin for 1 year (with a topical corticosteroid for the inguinal lesions), resulting in clearing of the cutaneous lesions. He underwent placement of bilateral double-J ureteral catheters and was started on hormone replacement therapy. At follow-up 1 year after treatment with acitretin ceased, the patient remained free of cutaneous lesions and his overall condition, including the retroperitoneal fibrosis, had improved. This case had an uncommon combination of features, with a good response to acitretin.


Subject(s)
Acitretin/therapeutic use , Adrenal Cortex Hormones/therapeutic use , Histiocytosis, Langerhans-Cell/drug therapy , Keratolytic Agents/therapeutic use , Drug Therapy, Combination , Groin , Histiocytosis, Langerhans-Cell/pathology , Humans , Male , Middle Aged , Time Factors , Treatment Outcome
6.
Clin Genet ; 76(3): 242-55, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19793053

ABSTRACT

Patients presenting familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP) or multiple colorectal adenomas (MCRAs) phenotype are clinically difficult to distinguish. We aimed to genetically characterize 107 clinically well-characterized patients with FAP-like phenotype, and stratified according to the recent guidelines for the clinical management of FAP: FAP, AFAP, MCRA (10-99 colorectal adenomas) without family history of colorectal cancer or few adenomas (FH), MCRA (10-99) with FH, MCRA (3-9) with FH. Overall, APC or MUTYH mutations were detected in 42/48 (88%), 14/20 (70%) and 10/38 (26%) of FAP, AFAP and MCRA patients, respectively. APC and MUTYH mutations accounted for 81% and 7% of FAP patients and for 30% and 40% of AFAP patients, respectively. Notably, MCRA patients did not present APC mutations. In 26% of these patients, an MUTYH mutation was identified and the detection rate increased with the number of adenomas, irrespectively of family history, being significantly higher in MCRA patients presenting more than 30 adenomas [7/12 (58%) vs 2/14 (14%), p = 0.023]. We validate the recently proposed guidelines in our patient's cohort and show that APC or MUTYH germline defects are responsible for the majority of clinically well-characterized patients with FAP and AFAP phenotype, and patients with more than 30 colorectal adenomas. The different mutation frequencies according to family history and to the number of adenomas underscore the importance of an adequate familial characterization, both clinically and by colonoscopy, in the management of FAP-like phenotypes. The phenotypes of the mutation-negative patients suggest distinct etiologies in these cases.


Subject(s)
Adenoma/enzymology , Adenoma/genetics , Adenomatous Polyposis Coli Protein/genetics , Adenomatous Polyposis Coli/enzymology , Adenomatous Polyposis Coli/genetics , DNA Glycosylases/genetics , Mutation/genetics , Adolescent , Adult , Aged , Alleles , Cohort Studies , Colorectal Neoplasms/genetics , DNA Mutational Analysis , Family , Genetic Testing , Humans , Middle Aged , Phenotype
7.
Dig Dis Sci ; 54(12): 2671-9, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19130226

ABSTRACT

The purpose of this study was to conduct a survey examining the impact of inflammatory bowel disease (IBD) on patients' and their caregivers' daily activities. Questionnaires were distributed to patients registered in the APDI (Portuguese Association for IBD) database and their respective caregivers in 2007. Of 422 patient respondents, 251 had Crohn's disease (CD) and 171 had ulcerative colitis (UC), with the majority of patients being women (58.1%) and aged over 40 years (37.4%). The number of disease flares experienced by IBD patients was slightly higher for patients with CD than for patients with UC (2.64 vs. 2.34), and surgery was more often required in CD patients as compared to UC patients (42.4 vs. 7%). Sixty percent (60%) of patients reported having no problems with mobility, daily activities, or personal hygiene; however, over half of all patients experienced some pain and anxiety. Adult patients and children and adolescents respectively experienced time off work or school due to their disease but caregivers were not affected in this regard. The caregivers life (N=324) was affected by anxiety, with the major concern reported as the risk of the patient developing cancer. Both IBD patients and caregivers thought that the provision of information on new drugs and contact time with a doctor would have the biggest impact on improving care. The symptoms and complications of IBD have a considerable impact on the lives of patients and their caregivers, and several actions could be taken to improve their care.


Subject(s)
Activities of Daily Living , Caregivers/psychology , Colitis, Ulcerative/psychology , Crohn Disease/psychology , Quality of Life , Adaptation, Psychological , Adult , Anxiety/etiology , Colitis, Ulcerative/complications , Colitis, Ulcerative/therapy , Cost of Illness , Crohn Disease/complications , Crohn Disease/therapy , Drug Information Services , Employment , Female , Health Knowledge, Attitudes, Practice , Health Surveys , Humans , Hygiene , Male , Mobility Limitation , Pain/psychology , Patient Education as Topic , Physician-Patient Relations , Portugal , Quality of Health Care , Registries , Surveys and Questionnaires , Young Adult
8.
J Eur Acad Dermatol Venereol ; 23(6): 678-82, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19298487

ABSTRACT

BACKGROUND: Sarcoidosis is a granulomatous disease of uncertain aetiology in which the skin is frequently involved. Naked sarcoidal granulomas are the characteristic histological feature in specific lesions of sarcoidosis. OBJECTIVE: This study aims to describe the histological findings in a population of patients with cutaneous sarcoidosis. MATERIALS AND METHODS: This study is a retrospective analysis of 31 biopsies of specific lesions of cutaneous sarcoidosis, corresponding to 30 patients. RESULTS: Typical naked granuloma was found in the majority of cases (71%). In 9 cases (29%), granulomas had a significant number of lymphocytes. Necrosis was found in two cases (6%). Periadnexal distribution (mostly perisudoral) was found in 32% of cases. Interstitial distribution of granulomas was observed in five cases (16%). Foreign material was detected in 13% of cases (without the use of polarized light microscopy). Epidermal changes were found in 55% of cases, with atrophy and parakeratosis being the most frequent alterations. CONCLUSIONS: Although typical naked sarcoid granulomas are the most common features of cutaneous sarcoidosis, the dermatopathologist must be aware of possible atypical findings, which are more common than previously expected, because of the differential diagnosis with other causes of cutaneous granulomas, namely infectious diseases.


Subject(s)
Sarcoidosis/pathology , Skin Diseases/pathology , Adult , Aged , Biopsy , Female , Humans , Male , Middle Aged , Retrospective Studies
9.
Acta Gastroenterol Belg ; 82(3): 389-395, 2019.
Article in English | MEDLINE | ID: mdl-31566326

ABSTRACT

BACKGROUND AND AIM: Preoperative biliary drainage (PBD) in patients with pancreatic cancer remains debatable. The aim of this study was to analyse the indications for PBD in patients performing pancreaticoduodenectomy (PD) and to evaluate the impact of this procedure on postoperative outcome. METHODS: Observational retrospective cohort study of patients undergoing PD for pancreatic cancer. Clinical data and postoperative outcome, namely complications and 90-day mortality, were prospectively collected and compared between patients performing PBD or direct surgery (DS). RESULTS: Eighty-two patients were included: 40 underwent PBD and 42 performed DS. Major complications (27.5% vs 33.3%, P=0.156) and 90-day mortality (10% vs 16.7%, P=0.376) were similar between the two groups. There was a trend for higher mean total bilirubin in patients with PBD (P=0.073). The indication for PBD was suspicion of cholangitis/choledocholithiasis or need to perform neoadjuvant chemotherapy in 24 (60%) patients. In the remaining, elevated bilirubin was probably the only reason to perform PBD. Length of hospital stay was longer in PBD group (P=0.003). On multiple logistic regression, 90-day mortality was not related with preoperative bilirubin levels, biliary drainage or its indication, but solely with age (OR 1.15, 95%CI 1.05-1.31, P=0.008). CONCLUSIONS: PBD is often performed in patients undergoing PD without a formal indication, mainly due to high bilirubin levels. No increased morbidity/mortality was observed but length of hospital stay was prolonged in patients performing PBD.


Subject(s)
Drainage/adverse effects , Pancreaticoduodenectomy/methods , Postoperative Complications/prevention & control , Preoperative Care/methods , Bilirubin/blood , Drainage/methods , Humans , Pancreaticoduodenectomy/adverse effects , Retrospective Studies , Treatment Outcome
10.
J Crohns Colitis ; 13(11): 1387-1393, 2019 Oct 28.
Article in English | MEDLINE | ID: mdl-30989180

ABSTRACT

BACKGROUND AND AIMS: Golimumab has an established exposure-response relationship in patients with ulcerative colitis [UC]. However, the association of serum golimumab trough levels [TL] with objective markers of disease activity, such as endoscopic and histological activity scores and concentrations of biomarkers, remains less understood. This report describes the relationship of serum golimumab TL at the end of the induction period [Week 6] with clinical, endoscopic, histological, and biomarker parameters. METHODS: This was an open-label, uncontrolled, prospective and interventional study. Moderate to severely active UC patients naïve to biologic therapy were treated with golimumab. Serum golimumab TL and faecal calprotectin levels were measured at baseline [Week 0 of induction] and Week 6. RESULTS: A total of 34 patients completed the induction phase [Week 6] and were included in this analysis. Overall, 47.1% and 14.7% of patients achieved clinical response and remission with significantly higher serum golimumab TL in patients with early response or remission [3.7 µg/mL vs 1.3 µg/mL, p = 0.0013; and 3.1 µg/mL vs 1.7 µg/mL, p = 0.0164, respectively]. In addition, golimumab TL were significantly higher in patients achieving histological remission [4.2 µg/mL vs 1.7 µg/mL, p = 0.0049]. Week 6 golimumab TL were inversely correlated with the total Mayo score [rs = -0.546; p = 0.0008], the Mayo endoscopic subscore [rs = -0.381; p = 0.0262], the Geboes histological activity score [rs = -0.464; p = 0.0057], and faecal calprotectin levels [rs = -0.497; p = 0.0044]. CONCLUSIONS: A higher early exposure to golimumab is associated with a better objective response in active UC patients and appears to drive the outcome at Week 6.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/blood , Colitis, Ulcerative/drug therapy , Adult , Biomarkers/analysis , C-Reactive Protein/analysis , Colitis, Ulcerative/pathology , Dose-Response Relationship, Drug , Drug Administration Schedule , Drug Therapy, Combination , Endoscopy, Gastrointestinal , Feces/chemistry , Female , Gastrointestinal Agents/administration & dosage , Gastrointestinal Agents/blood , Glucocorticoids/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Leukocyte L1 Antigen Complex/analysis , Male , Portugal , Prospective Studies , Remission Induction
11.
United European Gastroenterol J ; 6(1): 112-122, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29435321

ABSTRACT

BACKGROUND: Patients with primary sclerosing cholangitis associated with inflammatory bowel disease (PSC-IBD) have a very high risk of developing colorectal neoplasia. Alterations in the gut microbiota and/or gut bile acids could account for the increase in this risk. However, no studies have yet investigated the net result of cholestasis and a potentially altered bile acid pool interacting with a dysbiotic gut flora in the inflamed colon of PSC-IBD. AIM: The aim of this study was to compare the gut microbiota and stool bile acid profiles, as well as and their correlation in patients with PSC-IBD and inflammatory bowel disease alone. METHODS: Thirty patients with extensive colitis (15 with concomitant primary sclerosing cholangitis) were prospectively recruited and fresh stool samples were collected. The microbiota composition in stool was profiled using bacterial 16S rRNA sequencing. Stool bile acids were assessed by high-performance liquid chromatography tandem mass spectrometry. RESULTS: The total stool bile acid pool was significantly reduced in PSC-IBD. Although no major differences were observed in the individual bile acid species in stool, their overall combination allowed a good separation between PSC-IBD and inflammatory bowel disease. Compared with inflammatory bowel disease alone, PSC-IBD patients demonstrated a different gut microbiota composition with enrichment in Ruminococcus and Fusobacterium genus compared with inflammatory bowel disease. At the operational taxonomic unit level major shifts were observed within the Firmicutes (73%) and Bacteroidetes phyla (17%). Specific microbiota-bile acid correlations were observed in PSC-IBD, where 12% of the operational taxonomic units strongly correlated with stool bile acids, compared with only 0.4% in non-PSC-IBD. CONCLUSIONS: Patients with PSC-IBD had distinct microbiota and microbiota-stool bile acid correlations as compared with inflammatory bowel disease. Whether these changes are associated with, or may predispose to, an increased risk of colorectal neoplasia needs to be further clarified.

13.
Cancer Res ; 52(18): 5002-6, 1992 Sep 15.
Article in English | MEDLINE | ID: mdl-1516055

ABSTRACT

In patients with ulcerative colitis, epidemiological work has suggested an association between low folate status and an increased risk of colonic neoplasia. The aim of the present study was to determine if experimental folate deficiency increases the likelihood of developing neoplasia in rats treated with the carcinogen dimethylhydrazine. Weanling male Sprague-Dawley rats were fed with an amino acid-defined diet containing either 8 or 0 mg/kg folic acid. After 5 weeks of defined diet, weekly s.c. injections of dimethylhydrazine (20 mg/kg) were administered to both groups. Serum, whole blood, liver, and colonic folate concentrations at the time of sacrifice were significantly lower in folate-depleted animals (P less than 0.001). There were significant differences in the incidence of colonic neoplasia between the two groups after 20 weeks of dimethylhydrazine exposure: folate-deficient rats had a greater incidence of dysplasia (6 of 7 versus 2 of 7 animals; P less than 0.05) and carcinoma (6 of 7 versus 1 of 7 animals; P less than 0.01). Furthermore, a significantly greater proportion of folate-replete rats than folate-deficient rats were free of neoplastic lesions (5 of 7 versus 0 of 7 animals; P less than 0.05). These results suggest that, in this animal model, folate deficiency increases the risk of malignancy when there is an underlying predisposition to colorectal cancer.


Subject(s)
Colonic Neoplasms/chemically induced , Folic Acid Deficiency/complications , Animals , Body Weight/drug effects , Dimethylhydrazines , Male , Rats , Rats, Inbred Strains
14.
Eur J Hum Genet ; 8(1): 49-53, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10713887

ABSTRACT

Mutation searching was performed in the hMSH2 and hMLH1 genes in 20 Portuguese families representing 124 registered affected individuals. Of the 20, 16 fulfilled the classic 'Amsterdam' criteria for HNPCC, whereas the remaining four families satisfied a modified set of criteria. These criteria required a CRC diagnosed before age 50 years and cancers diagnosed in two other relatives within the HNPCC spectrum. A multi-method approach was performed using the protein truncation test (PTT), single strand conformation polymorphism (SSCP) with two different sets of conditions, heteroduplex analysis (HA) and denaturing gradient gel electrophoresis (DGGE). Putative phenotype-genotype correlations were also explored. Ten different germline mutations were identified. Six of these were found in hMLH1 in seven families and four in hMSH2 in four families. SSCP and DGGE had the highest diagnostic yields with the percentage of variants detected above 67% and together HA and PTT had the lowest. No single technique detected all variants. Trends for the absence of extracolonic manifestations were observed in families carrying hMLH1 germline mutations (four of seven in hMLH1 vs one of four in hMSH2). Most of the families with rectal cancer were associated with hMLH1 (six of seven in hMLH1 vs two of four in hMSH2). A multi-technique approach is necessary to identify a high percentage of germline mutations. Seven novel mutations were found in this Portuguese population.


Subject(s)
Base Pair Mismatch , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , DNA Repair , DNA-Binding Proteins , Neoplasm Proteins/genetics , Proto-Oncogene Proteins/genetics , Adaptor Proteins, Signal Transducing , Carrier Proteins , DNA/analysis , DNA/blood , DNA Mutational Analysis/methods , Female , Humans , Male , MutL Protein Homolog 1 , MutS Homolog 2 Protein , Nuclear Proteins , Polymorphism, Single-Stranded Conformational , Portugal , RNA/analysis , RNA/blood
15.
Am J Clin Nutr ; 53(6): 1450-54, 1991 Jun.
Article in English | MEDLINE | ID: mdl-2035472

ABSTRACT

In this study the deoxyuridine suppression test (dUST) was performed on isolated rat colonocytes to establish its value as an indicator of folate status in the colonic epithelium. [3H]thymidine incorporation into DNA was suppressed greater than 90% by deoxyuridine (dU) concentrations greater than 2.5 mumol/L. Preincubation of cells with 5-fluorouracil (1-100 mumol/L) but not methotrexate (10-100 mumol/L) resulted in a significant decrease in the degree of suppression. The dUST performed on colonocytes from folate-deficient animals displayed less suppression than on colonocytes from folate-replete animals (P less than 0.05). The abnormal degree of suppression was corrected by adding 100 mumol folinic acid/L. There was a negative correlation between the degree of suppression and the folate concentration of the colonic epithelium (P less than 0.001). These data indicate that the dUST is useful for detecting folate deficiency in the colonic epithelium and may therefore be valuable in assessing a deficiency state localized to that epithelium.


Subject(s)
Colon/chemistry , Deoxyuridine , Folic Acid/analysis , Animals , Cells, Cultured , Colon/cytology , DNA/metabolism , Epithelium/chemistry , Fluorouracil/metabolism , Male , Rats , Rats, Inbred Strains , Thymidine/metabolism
16.
Am J Clin Nutr ; 61(5): 1083-90, 1995 May.
Article in English | MEDLINE | ID: mdl-7733033

ABSTRACT

Global and gene-specific DNA hypomethylation is considered to be an important early epigenetic event in several human neoplasms. A growing body of evidence has suggested that DNA methylation can be altered by dietary manipulation of methyl group donors. This study investigated whether moderate depletion of folate, a dietary component needed for the synthesis of methyl groups, would cause decreased hepatic and colonic S-adenosylmethionine concentrations, and thereby lead to global and/or protooncogene-specific DNA hypomethylation. Weanling rats were fed an amino acid-defined diet containing either 0 or 8 mg folate/kg diet for 15 or 24 wk. Significantly lower systemic, hepatic and colonic folate concentrations were observed in the moderately folate-depleted rats than in controls at both 15 and 24 wk (P < 0.005). Although hepatic S-adenosylmethionine was significantly lower in the moderately folate-depleted rats than in controls at the two time points (P < 0.03), colonic S-adenosylmethionine concentrations were not significantly different between the two groups at either time point. No significant differences between the folate-depleted and control animals could be detected with regard to global DNA methylation in the liver or colonic mucosa. Furthermore, c-myc protooncogene-specific DNA methylation in the colonic mucosa was not significantly different between these two groups of animals. These results indicate that moderate folate depletion does not cause a significant reduction in global DNA methylation in liver or colonic mucosa or in c-myc-specific colonic mucosal DNA methylation in this rat model.


Subject(s)
Colon/chemistry , DNA/metabolism , Folic Acid Deficiency/metabolism , Genes, myc/genetics , Liver/chemistry , Animals , Body Weight , Colon/metabolism , Colorectal Neoplasms/etiology , Colorectal Neoplasms/genetics , DNA/analysis , Folic Acid/pharmacology , Folic Acid Deficiency/physiopathology , Gene Expression Regulation, Neoplastic , Liver/metabolism , Male , Methionine/metabolism , Methylation , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Random Allocation , Rats , Rats, Sprague-Dawley , S-Adenosylmethionine/analysis , S-Adenosylmethionine/metabolism
17.
Am J Clin Nutr ; 63(2): 220-4, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8561063

ABSTRACT

Serum homocysteine concentrations have been shown to be a sensitive functional indicator of intracellular folate, vitamin B-12, and vitamin B-6 status. Chronic alcoholism is known to interfere with one-carbon metabolism, for which the above vitamins serve as coenzymes. In the present study, these vitamins were assessed in 32 chronic alcoholics and 31 healthy volunteers by measuring blood vitamin concentrations as well as serum homocysteine concentrations. In chronic alcoholics, serum pyridoxal 5'-phosphate and red blood cell folate concentrations were significantly lower than in the control subjects (P < 0.001 and P = 0.008, respectively). Mean serum homocysteine was twice as high in chronic alcoholics than in nondrinkers (P < 0.001). Beer consumers had significantly lower concentrations of homocysteine compared with drinkers of wine or spirits (P = 0.05). These results suggest that by interfering with folate or vitamin B-6 metabolism, chronic alcohol intake may impair the disposal of homocysteine through the transmethylation or transsulfuration pathways.


Subject(s)
Alcoholism/blood , Folic Acid/blood , Homocysteine/blood , Pyridoxine/blood , Vitamin B 12/blood , Adult , Blood Cell Count , Erythrocyte Indices , Female , Humans , Male , Middle Aged , Nutritional Status
18.
Cancer Genet Cytogenet ; 111(2): 152-6, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10347554

ABSTRACT

Germ-line mutations in the adenomatous polyposis coli (APC) gene are responsible for familial adenomatous polyposis (FAP). In the present study, we have used the protein truncation test to screen for mutations in exon 15 and exons 1-14 of the APC gene and denaturing gradient gel electrophoresis to analyze exons 1-14. We have studied nine unrelated FAP kindreds, eight with the classical phenotype and one with an atypical phenotype, with several family members exhibiting fewer than 50 colonic polyps. The combined use of these two methodologies allowed the identification of seven novel mutations, with two unrelated families sharing the same mutation. All mutations were chain terminating: six resulted from small deletions, one from a small insertion, and one was a point mutation, resulting in a premature stop codon. Seven mutations were located in exon 15 of the APC gene, one was in exon 10, and the remaining one, which corresponded to the kindred with an atypical phenotype, was located in exon 4.


Subject(s)
Adenomatous Polyposis Coli/genetics , Cytoskeletal Proteins/genetics , Genes, APC , Mutation , Adenomatous Polyposis Coli Protein , Cytoskeletal Proteins/metabolism , DNA Mutational Analysis , Electrophoresis/methods , Female , Humans , Male , Pedigree , Phenotype , Portugal
19.
Eur J Cancer Prev ; 3(6): 473-9, 1994 Nov.
Article in English | MEDLINE | ID: mdl-7858479

ABSTRACT

Several studies have suggested that DNA hypomethylation is an early step in colorectal carcinogenesis. However, it is not clear at which stage in carcinogenesis this hypomethylation occurs, what promotes it, the extent to which it can be reversed and the consequences of such reversal in affecting tumour development. In an attempt to address some of these questions, we studied three groups of subjects with similar age and gender distributions: a group of 12 patients with colorectal carcinomas; a group of 12 patients with colorectal adenomas; and a group of eight healthy control subjects. Two experimental protocols were employed. In the first protocol, intrinsic DNA methylation was evaluated in neoplastic and in normal-appearing rectal mucosa of patients with colonic carcinomas or adenomas, compared with a group of healthy controls. In the second protocol, we examined, in a prospective and controlled fashion, the effect of folic acid supplementation (10 mg/day) on the degree of DNA methylation of rectal mucosa from those same patients after removal of the neoplasms. The degree of intrinsic DNA methylation was assessed on the basis of the capacity of the DNA isolates to serve as methyl acceptors in in vitro incubations that contained DNA methylase and [3H-methyl] S-adenosylmethionine. Intrinsic DNA methylation was significantly lower in carcinomas than in adenomas (P < 0.005). In addition, normal-appearing rectal mucosa from patients with carcinomas was significantly less methylated than in healthy controls (P < 0.005); the mean value found in the latter was also greater than the value observed in patients with adenomas, but not significantly so (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Adenoma/diagnosis , Carcinoma/diagnosis , Colorectal Neoplasms/diagnosis , DNA/metabolism , Folic Acid/therapeutic use , Adenoma/metabolism , Adenoma/prevention & control , Adult , Aged , Biomarkers, Tumor , Carcinoma/metabolism , Carcinoma/prevention & control , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/prevention & control , Female , Humans , In Vitro Techniques , Intestinal Mucosa/metabolism , Male , Methylation , Middle Aged , Prospective Studies
20.
J Neurosurg ; 49(3): 425-8, 1978 Sep.
Article in English | MEDLINE | ID: mdl-682004

ABSTRACT

An unusual case of infection of the central nervous system by Paracoccidioides braziliensis, presenting as posterior fossa tumor, is discussed and the pertinent literature reviewed.


Subject(s)
Brain Diseases/diagnosis , Paracoccidioidomycosis/diagnosis , Skull Neoplasms/diagnosis , Brain Diseases/surgery , Cranial Fossa, Posterior , Diagnosis, Differential , Humans , Male , Middle Aged , Paracoccidioidomycosis/surgery
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