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1.
Histopathology ; 49(1): 45-51, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16842245

ABSTRACT

AIMS: A substantial minority of intestinal metaplasia (IM)-associated stomach cancers express a gastric product-pepsinogen group II (PGII). The aim of this study was to examine PGII expression as it relates to IM and to tumour heterogeneity. METHODS AND RESULTS: The extent of IM was divided into four levels: none, minimal, moderate, extensive. Stomach specimens (N = 165) were stained for PGII and two tumour markers, epidermal growth factor receptor (EGFr) and p53. PGII was more likely to be expressed with moderate or extensive IM than with minimal or no IM (P = 0.05). Cancers that expressed PGII were more likely to be of high stage than those that did not (P = 0.035). Of 25 cases that expressed all three markers (PGII, EGFr, p53), 20 (80%) had stage 3 or 4 disease, compared with 11 (37%) advanced cancers expressing none of the markers (P = 0.001). Cancers expressing one or two markers were between these extremes. CONCLUSIONS: PGII+ cancers in IM-associated gastric cancers may derive from residual gastric glands, or may arise from postinduction reversion to a gastric phenotype from intestinalized cells. This is supported by the more frequent association of PGII expression with the most extensive degrees of IM and its association with high-stage cancers that display heterogeneity in tumour marker expression.


Subject(s)
Gastric Mucosa/enzymology , Gastric Mucosa/pathology , Pepsinogen C/metabolism , Stomach Neoplasms/enzymology , Stomach Neoplasms/pathology , Biomarkers, Tumor/metabolism , ErbB Receptors/metabolism , Humans , Immunohistochemistry , Male , Metaplasia , Risk Factors , Stomach Neoplasms/etiology , Tumor Suppressor Protein p53/metabolism
3.
Hum Mutat ; 21(3): 258-70, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12619111

ABSTRACT

In this article, we survey the major p53 (TP53) alterations identified in gastric carcinomas and their precursors. These include p53 expression, mutations, and loss of heterozygosity (LOH). Not only are the various abnormalities summarized, but in addition there is a survey of the literature with respect to the impact of these changes on patient prognosis and treatment response. The majority of published studies involve the immunohistochemical detection of the protein. These use different antibodies, different detection techniques, and different methods of interpretation. Therefore not surprisingly, the results of many of the studies are contradictory with one another. Overall, however, it appears that p53 alterations occur early in the development of gastric carcinoma, being present even in the nonneoplastic mucosa and they increase in frequency as one progresses along the pathway of gastric carcinoma development. p53 immunoreactivity is seen in 17%-90.7% of invasive gastric carcinomas. p53 alterations occur much more commonly in proximal lesions than in distal ones, suggesting that the molecular events leading to the development of gastric carcinoma may be very different in proximal vs. distal tumors. p53 mutations occur in 0%-77% of gastric carcinomas. The mutations are distributed widely across the gene from exons 4-11 with hot spots of mutation at codons 175, 248, 273, 282, 245, and 213. G:C>A:T transitions at CpG sites are the commonest type of mutation. At least 60% of carcinomas with mutations also exhibit p53 LOH.


Subject(s)
Stomach Neoplasms/genetics , Tumor Suppressor Protein p53/genetics , Gene Expression Regulation, Neoplastic , Humans , Loss of Heterozygosity , Mutation
4.
N Engl J Med ; 345(10): 725-30, 2001 Sep 06.
Article in English | MEDLINE | ID: mdl-11547741

ABSTRACT

BACKGROUND: Surgical resection of adenocarcinoma of the stomach is curative in less than 40 percent of cases. We investigated the effect of surgery plus postoperative (adjuvant) chemoradiotherapy on the survival of patients with resectable adenocarcinoma of the stomach or gastroesophageal junction. METHODS: A total of 556 patients with resected adenocarcinoma of the stomach or gastroesophageal junction were randomly assigned to surgery plus postoperative chemoradiotherapy or surgery alone. The adjuvant treatment consisted of 425 mg of fluorouracil per square meter of body-surface area per day, plus 20 mg of leucovorin per square meter per day, for five days, followed by 4500 cGy of radiation at 180 cGy per day, given five days per week for five weeks, with modified doses of fluorouracil and leucovorin on the first four and the last three days of radiotherapy. One month after the completion of radiotherapy, two five-day cycles of fluorouracil (425 mg per square meter per day) plus leucovorin (20 mg per square meter per day) were given one month apart. RESULTS: The median overall survival in the surgery-only group was 27 months, as compared with 36 months in the chemoradiotherapy group; the hazard ratio for death was 1.35 (95 percent confidence interval, 1.09 to 1.66; P=0.005). The hazard ratio for relapse was 1.52 (95 percent confidence interval, 1.23 to 1.86; P<0.001). Three patients (1 percent) died from toxic effects of the chemoradiotherapy; grade 3 toxic effects occurred in 41 percent of the patients in the chemoradiotherapy group, and grade 4 toxic effects occurred in 32 percent. CONCLUSIONS: Postoperative chemoradiotherapy should be considered for all patients at high risk for recurrence of adenocarcinoma of the stomach or gastroesophageal junction who have undergone curative resection.


Subject(s)
Adenocarcinoma/surgery , Antimetabolites, Antineoplastic/therapeutic use , Esophagogastric Junction/surgery , Fluorouracil/therapeutic use , Stomach Neoplasms/surgery , Adenocarcinoma/drug therapy , Adenocarcinoma/mortality , Adenocarcinoma/radiotherapy , Adult , Aged , Aged, 80 and over , Antimetabolites, Antineoplastic/adverse effects , Combined Modality Therapy , Disease-Free Survival , Female , Fluorouracil/adverse effects , Gastrectomy , Humans , Leucovorin/therapeutic use , Lymph Node Excision , Male , Middle Aged , Radiation Dosage , Stomach Neoplasms/drug therapy , Stomach Neoplasms/mortality , Stomach Neoplasms/radiotherapy , Survival Rate
5.
Comp Med ; 50(5): 511-5, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11099134

ABSTRACT

Mice lacking the NHE2 Na+/H+ gene develop gastritis of the glandular mucosa as early as the tenth day of life, achieving maximal intensity of inflammation from 17 to 19 days after birth and maximal atrophy at one year. We assessed the effects of this process in such mice to 16 months of age. The stomach of NHE2 null mutants was examined at 10, 17 to 20, 24 to 35 and 49 to 70 days, and at 12 to 16 months. The NHE2 wild-type (+/+) and NHE2 heterozygous (+/-) mice were compared with the NHE2 homozygous mutant mice (-/-). The stomach of the mutant mice at all ages was characterized by a substantially reduced number of parietal cells. The 10-day-old mouse stomach had a transmural infiltrate of primarily neutrophils. With increasing age, neutrophils were replaced by lymphocytes and plasma cells in the glandular mucosa of the mutant mice. Young adult 49- to 70-day-old mice had surface cell hyperplasia and expansion of the replicating cell population. Hyperplasia of enterochromaffin-like cells and antral gastrin cells accompanied profound fundic gland and surface cell hyperplasia, and became progressively more severe with increasing age of the NHE2-/- mice. Neoplasms were not found in the mutant or control mice. This gastritis differs from that of autoimmune gastritis in that it is transmural, begins in infancy, and is associated with a predominantly neutrophilic infiltrate in its early stages. Some of the histologic changes in the adult mice can be explained on the basis of prolonged achlorhydria. This mouse may be a suitable model for prolonged effects of achlorhydria.


Subject(s)
Gastric Mucosa/pathology , Gastritis, Atrophic/veterinary , Mice, Knockout/physiology , Rodent Diseases/pathology , Sodium-Hydrogen Exchangers/physiology , Stomach/pathology , Age Factors , Animals , Disease Models, Animal , Female , Gastritis, Atrophic/genetics , Gastritis, Atrophic/pathology , Immunohistochemistry/veterinary , Male , Mice , Rodent Diseases/genetics , Sodium-Hydrogen Exchangers/genetics
6.
Cancer Epidemiol Biomarkers Prev ; 9(9): 883-7, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11008904

ABSTRACT

It is suspected that selenium is protective against prostate cancer. To test this hypothesis, we conducted a nested case-control study in a cohort of 9345 Japanese-American men examined between 1971 and 1977. At the time of examination, a blood specimen was obtained, and the serum was frozen. After a surveillance period of more than 20 years, 249 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 249 matched controls were measured for selenium levels. Odds ratios for prostate cancer, based on quartiles of serum selenium levels, were determined using the General Estimating Equations approach. The multivariate odds ratio for the highest quartile was 0.5 (95% confidence interval, 0.3-0.9) with a two-sided P for trend of 0.02. The inverse association was more notable for cases with advanced disease and for cases diagnosed 5-15 years after phlebotomy. However, the association was mainly present in current or past cigarette smokers rather than nonsmokers, which leads to caution in the interpretation of the results.


Subject(s)
Prostatic Neoplasms/blood , Selenium/blood , Aged , Case-Control Studies , Hawaii/epidemiology , Humans , Incidence , Male , Middle Aged , Odds Ratio , Prostatic Neoplasms/epidemiology , Prostatic Neoplasms/etiology , Risk Factors , Smoking/adverse effects , Smoking/blood
7.
Gastroenterology ; 118(6): 1039-44, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10833478

ABSTRACT

BACKGROUND & AIMS: Our long-term goal was to evaluate the role of p53 in the prognosis of gastric cancer. We previously showed a discrepancy between p53 expression and the presence of mutations when only exons 5-9 were examined. We then evaluated exon 4. METHODS: DNA was sequenced from 217 gastric cancers to detect exon 4 alterations. Codon 72 was examined by restriction enzyme digestion. RESULTS: Mutations were present in 3.2% of tumors. In addition, 2 polymorphic sites were found at codons 36 and 72. Polymorphisms at codon 36 were only found in 2 patients. In contrast, the codon 72 polymorphism was very frequent. The genotype frequency was arg/arg (54%), arg/pro (33%), and pro/pro (14%). The genotype of the polymorphic site varied with race (P = 0.001): 64% of whites had the arg/arg genotype, compared with 24% of blacks. The difference in genotype by site, sex, or histological tumor type was not statistically significant (P = 0.067). CONCLUSIONS: There are several exon 4 alterations in gastric cancers. These include the rare mutations and the very rare codon 36 polymorphism. The most common change is the codon 72 polymorphism, the genotype of which differs significantly with race. The more common arg/arg genotype in whites may explain why whites are more prone to develop cardiac cancer, whereas the more common proline allele in blacks may explain why they are more prone to develop antral cancers. Further studies are required to determine whether the codon 72 polymorphism affects patient predisposition to gastric cancer.


Subject(s)
Carcinoma, Medullary/genetics , Exons/genetics , Gene Expression Regulation, Neoplastic , Stomach Neoplasms/genetics , Tumor Suppressor Protein p53/genetics , Adenocarcinoma, Mucinous/ethnology , Adenocarcinoma, Mucinous/genetics , Apoptosis/genetics , Asian People/genetics , Black People/genetics , Carcinoid Tumor/ethnology , Carcinoid Tumor/genetics , Carcinoma, Medullary/ethnology , DNA-Binding Proteins/genetics , Female , Frameshift Mutation , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Male , Point Mutation , Polymorphism, Genetic , Stomach Neoplasms/ethnology , Transcription, Genetic/genetics , White People/genetics
8.
Cancer Epidemiol Biomarkers Prev ; 8(12): 1111-4, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10613345

ABSTRACT

The aim of this study was to determine whether EBV associates with esophageal squamous cell carcinoma (ESCC), the most common malignancy in some parts of northern China, because these tumors frequently have an intense lymphocyte infiltrate. Fifty-one paraffin-embedded samples of ESCC from a high-risk area of North China were studied. The tumors included 9 well-differentiated, 31 moderately differentiated, and 11 poorly differentiated tumors. The cancer tissues and their nonmalignant adjacent mucosa (16 dysplastic and 42 normal) were evaluated by in situ hybridization using an antisense EBV-encoded RNA-1 probe and PCR amplification for EBV BamHI W fragment. In all cases, EBV was negative by both in situ hybridization and PCR. Our study suggests that EBV does not play a role in the carcinogenesis of ESCC in the geographic region.


Subject(s)
Carcinoma, Squamous Cell/epidemiology , Carcinoma, Squamous Cell/etiology , Epstein-Barr Virus Infections/complications , Esophageal Neoplasms/epidemiology , Esophageal Neoplasms/etiology , Adult , Age Distribution , Aged , Carcinoma, Squamous Cell/pathology , China/epidemiology , DNA, Viral/analysis , Esophageal Neoplasms/pathology , Female , Herpesvirus 4, Human/genetics , Humans , In Situ Hybridization , Male , Middle Aged , Polymerase Chain Reaction , Risk Factors , Sex Distribution
9.
Cancer Causes Control ; 10(3): 227-31, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10454068

ABSTRACT

OBJECTIVES: We investigated p53 gene mutations in advanced gastric cancers by direct DNA sequencing, in order to determine the frequency of mutations in gastric cancers having different epidemiological backgrounds, tumors of the cardia were compared with those arising in the antrum or corpus. Intestinal type cancers were compared with diffuse or other histologic types. We have chosen to assess the frequency of mutations solely based on DNA sequencing. METHODS: Paraffin embedded tissues from 100 gastric cancers were evaluated. The mutational status of the p53 gene in exons 5 through 9 were determined by direct sequencing of PCR products. RESULTS: Mutations in exons 5, 6, 7 and 8 were found in 35 of 100(35%)stomach cancers. One tumor had mutations in both exons 5 and 8. No mutations were detected in exon 9. p53 gene mutations were significantly more frequent in cancers of the cardia (19/35; 54%) than the antrum and corpus (16/65 (25%)) (p < or = 0.005). p53 mutations were more frequent in intestinal type cancers (28/67; 42%) than diffuse cancers or other histologic types of cancer (7/33; 21%), but the difference was not statistically significant. CONCLUSIONS: Cancers of the cardia more frequently contain p53 mutations than do antral and corpus cancers, suggesting that cancers in the proximal and distal stomach evolve through different molecular pathways.


Subject(s)
DNA, Neoplasm/analysis , Genes, p53/genetics , Stomach Neoplasms/genetics , Base Sequence , DNA Mutational Analysis , Humans , Molecular Sequence Data , Phenotype , Polymerase Chain Reaction , Stomach/pathology , Stomach Neoplasms/pathology
10.
Mod Pathol ; 12(1): 54-60, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9950163

ABSTRACT

The intent of this study was to investigate the ability of p53 expression and single-strand conformational polymorphism analysis (SSCP) to predict p53 mutational status in archival, paraffin-embedded tissues of gastric cancer. We evaluated paraffin-embedded tissues from 78 patients with advanced gastric cancer. The mutational status of the p53 gene (exons 5-9) was examined by SSCP analysis and by direct sequencing. These results were compared with p53 expression as assessed by immunohistochemical analysis (IHC). We graded p53 expression on a scale from 0 to 8 on the basis of both the intensity and the number of cells staining. Overall, we detected p53 immunoreactivity in 75.6% of the gastric cases; 19 (32.2%) of these cases scored from 1 to 4, and 40 (67.8%) cases scored from 5 to 8. p53 gene mutations were detected in 18 cases (23.1%) by SSCP and in 28 cases (36%) by direct sequencing. Thus, SSCP failed to detect 38% of the mutations found by sequencing. The majority of missed mutations involved exons 7 and 8. The concordance between IHC and SSCP was 37%, and the concordance between IHC and direct sequencing was 50%. Forty-five percent of cases positive by IHC failed to show mutations in exons 5 through 9. Five percent of cases negative by IHC (4 cases) contained mutations. One had a 1-base pair insertion; one had a mutation that resulted in a stop codon; the third had a mutation in exon 8; and the fourth had a mutation in both exons 5 and 8. Our findings indicate that p53 immunoreactivity correlates with the presence or absence of gene mutations in 50% of advanced gastric cancers when exons 5 through 9 are examined and that IHC cannot be reproducibly used as a marker of mutation in the most commonly mutated exons of the p53 gene. Furthermore, the sensitivity of SSCP for detecting mutations is only 62%. Thus, SSCP analysis cannot be used reliably to screen for p53 mutations.


Subject(s)
DNA, Single-Stranded/genetics , Mutation/genetics , Polymorphism, Genetic/genetics , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Base Sequence/genetics , Forecasting , Gene Frequency , Humans , Immunohistochemistry , Molecular Conformation , Polymorphism, Single-Stranded Conformational
11.
Gastroenterology ; 116(1): 58-63, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9869603

ABSTRACT

BACKGROUND & AIMS: Colorectal cancer is one of the most frequent cancers in humans. Recently, a germline missense mutation, I1307K, was identified in the adenomatous polyposis coli (APC) gene that was suggested to increase cancer predisposition in Ashkenazi Jews. However, a second study indicated that the I1307K mutation did not contribute greatly to the risk of colon cancer in Ashkenazi breast-ovarian cancer families, and a role of mismatch repair deficiency was suggested. This study investigated the frequency of the I1307K mutation in several non-Ashkenazi Jewish populations. We also compared the distribution and frequency of APC mutations from colon tumors that were positive and negative for the I1307K mutation. Finally, the association between the presence of mutations in the I1307K region and mismatch repair deficiency was studied. METHODS: We tested for I1307K in 345 patients who were not Ashkenazi Jews using a heteroduplex screen. We also performed an extensive mutational analysis in this region of the APC gene on DNA extracted from 240 Italian, Finnish, and Hawaiian-Japanese colon tumors and determined replication error status. RESULTS: The I1307K mutation was not found among 345 non-Ashkenazis. Somatic mutations occurred at a lower frequency and were more randomly distributed when the I1307K allele was not present. The most common characteristic somatic mutation occurring around codon 1307 in I1307K-positive patients did not occur in tumors negative for the I1307K mutation. An association between mutations in the region around APC codon 1307 and mismatch repair deficiency was not found. CONCLUSIONS: Our findings support the hypothesis that the I1307K mutation is unique to the Ashkenazi Jews, contributes to tumor predisposition in colorectal cancer, and is unrelated to mismatch repair deficiency.


Subject(s)
Colorectal Neoplasms/genetics , Cytoskeletal Proteins/genetics , Genes, APC , Polymorphism, Genetic/genetics , Adenomatous Polyposis Coli Protein , Amino Acid Sequence , Base Sequence , Codon/genetics , Colorectal Neoplasms/ethnology , DNA/genetics , DNA Repair/genetics , Genetic Testing , Humans , Jews , Molecular Sequence Data , Mutation , Polymerase Chain Reaction
12.
Cancer Causes Control ; 9(4): 425-32, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9794175

ABSTRACT

OBJECTIVES: Because several serum studies of vitamin D metabolites have produced equivocal results on their relation to prostate cancer risk, the purpose of this study is to evaluate this association further. METHODS: A nested case-control study in a cohort of 3,737 Japanese-American men examined from 1967 to 1970 was conducted in Hawaii (United States). At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of over 23 years, 136 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 136 matched controls were measured for the following: 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, calcium, phosphorus, and parathyroid hormone. RESULTS: There were no notable differences between cases and controls in their median serum levels of the five laboratory measurements. Odds ratios (OR) for prostate cancer, based on the quartiles of serum levels in controls, were also determined. The ORs for the highest quartiles relative to the lowest were 0.8 (95 percent confidence interval [CI] = 0.4-1.8) for 25-hydroxyvitamin D and 1.0 (CI = 0.5-2.1) for 1,25-dihydroxyvitamin D. CONCLUSION: It is possible that the lack of sufficient numbers of study subjects with low vitamin D levels affected the results. Nonetheless, the findings suggest that there is a lack of a strong association between vitamin D and prostate cancer.


Subject(s)
Biomarkers, Tumor/analysis , Prostatic Neoplasms/blood , Prostatic Neoplasms/epidemiology , Vitamin D/blood , Age Distribution , Aged , Case-Control Studies , Cohort Studies , Hawaii/epidemiology , Humans , Incidence , Japan/ethnology , Male , Middle Aged , Odds Ratio , Population Surveillance , Risk Factors , Vitamin D/metabolism
13.
Hum Pathol ; 29(9): 992-9, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9744317

ABSTRACT

Carcinoid tumors are potentially malignant neoplasms that arise in various body sites, including the lung and gastrointestinal tract. Those that appear cytologically atypical are more likely to behave aggressively than more typical carcinoid tumors. However, in the absence of cytological atypia or large tumor size, it is difficult to predict the biology of an individual tumor, because some lesions metastasize, whereas others do not. This study had four aims: (1) To study the expression pattern of p53, Ki-67, NCAM, and S-100 in carcinoid tumors and to relate these expression patterns to classical histopathologic features and to tumor location. (2) To identify nonhistological markers that might more accurately predict the early behavior of carcinoid tumors. (3) To determine whether sustentacular cells are present in carcinoid tumors arising in tissues derived from different embryological derivatives. (4) To determine the synaptophysin and chromogranin immunoreactivity in neuroendocrine tumors arising in various locations. The immunostaining reactions were quantitatively scored by three observers. Only 3 of the 39 tumors (all histologically atypical) were strongly positive for Ki-67; two of these were also strongly p53 immunoreactive. NCAM immunostaining differed according to the site of origin: 76.5% of foregut lesions, 58% of the midgut lesions, and 20% of hindgut lesions were positive. S-100 immunostaining ranged from 41% in foregut lesions to 50% in both the hindgut- and midgut-derived tumors. S-100-positive sustentacular cells were present in 20.5% of carcinoid tumors. All tumors stained with antibodies against synaptophysin. In contrast, 100% of midgut, 60% of hindgut, and 88% of foregut tumors were chromogranin positive. Carcinoid tumors tend to have low proliferative rates. p53 immunostaining tends to be strongly positive in tumors that are histologically atypical, but it is negative in typical carcinoid tumors arising in the gastrointestinal tract and lungs. Immunostaining reactions with antibodies to NCAM, S-100, and chromogranin differ depending on the site of origin. Synaptophysin stains 100% of carcinoid tumors regardless of their site of origin. In contrast, antibodies to chromogranin fail to stain 40% of hindgut tumors and 12% of foregut carcinoid tumors. S-100-positive sustentacular cells are present in foregut and midgut tumors but not in hindgut tumors.


Subject(s)
Carcinoid Tumor/metabolism , Gastrointestinal Neoplasms/metabolism , Lung Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Carcinoid Tumor/pathology , Chromogranins/metabolism , Female , Gastrointestinal Neoplasms/pathology , Humans , Immunohistochemistry , Ki-67 Antigen/metabolism , Male , Middle Aged , Neoplasm Metastasis , Neural Cell Adhesion Molecules/metabolism , S100 Proteins/metabolism , Synaptophysin/metabolism , Tumor Suppressor Protein p53/metabolism
14.
Anticancer Res ; 18(4B): 2811-4, 1998.
Article in English | MEDLINE | ID: mdl-9713466

ABSTRACT

A one-page family history questionnaire was validated in two European areas covered by population-based cancer registries. Information on malignant tumor occurrence in first degree relatives was collected from 193 cancer patients in Trieste, Italy and from 64 in Basel, Switzerland. They were then compared with the corresponding data stored in the registries' files. The sensitivity of the questionnaire was 85% (Trieste) and 74% (Basel), the specificity was 97% in both studies and the overall accuracy 95% (Trieste) and 94% (Basel). The questionnaire is recommended for use in different geographical areas covered by population based registries for comparative analyses of cancer related family histories.


Subject(s)
Family Health , Neoplasms/epidemiology , Surveys and Questionnaires , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Pilot Projects , Reproducibility of Results , Sensitivity and Specificity
15.
J Clin Invest ; 101(6): 1243-53, 1998 Mar 15.
Article in English | MEDLINE | ID: mdl-9502765

ABSTRACT

Multiple isoforms of the Na+/H+ exchanger (NHE) are expressed at high levels in gastric epithelium, but the physiological role of individual isoforms is unclear. To study the function of NHE2, which is expressed in mucous, zymogenic, and parietal cells, we prepared mice with a null mutation in the NHE2 gene. Homozygous null mutants exhibit no overt disease phenotype, but the cellular composition of the oxyntic mucosa of the gastric corpus is altered, with parietal and zymogenic cells reduced markedly in number. Net acid secretion in null mutants is reduced slightly relative to wild-type levels just before weaning and is abolished in adult animals. Although mature parietal cells are observed, and appear morphologically to be engaged in active acid secretion, many of the parietal cells are in various stages of degeneration. These results indicate that NHE2 is not required for acid secretion by the parietal cell, but is essential for its long-term viability. This suggests that the unique sensitivity of NHE2 to inhibition by extracellular H+, which would allow upregulation of its activity by the increased interstitial alkalinity that accompanies acid secretion, might enable this isoform to play a specialized role in maintaining the long-term viability of the parietal cell.


Subject(s)
Acids/metabolism , Parietal Cells, Gastric/cytology , Parietal Cells, Gastric/metabolism , Sodium-Hydrogen Exchangers/genetics , Sodium-Hydrogen Exchangers/physiology , Adenosine Triphosphatases/metabolism , Amino Acid Sequence , Animals , Blotting, Northern , Cell Survival/genetics , Cell Survival/physiology , Cells, Cultured , Chromosome Mapping , Cloning, Molecular , DNA/analysis , DNA/genetics , DNA/metabolism , Female , Gastric Mucosa/cytology , Gastric Mucosa/metabolism , Gastrins/analysis , Gastrins/metabolism , Intestinal Mucosa/metabolism , Isomerism , Kidney/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Inbred ICR , Mice, Knockout , Molecular Sequence Data , Mutagenesis , Parietal Cells, Gastric/ultrastructure , Pepsinogens/metabolism , Polymerase Chain Reaction , Potassium/metabolism , Pregnancy , Protons , RNA, Messenger/analysis , RNA, Messenger/metabolism , Recombination, Genetic , Sequence Analysis, DNA , Sodium-Hydrogen Exchangers/metabolism , Stem Cells/metabolism
16.
Cancer Epidemiol Biomarkers Prev ; 6(7): 487-91, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9232334

ABSTRACT

Numerous dietary studies and several serum micronutrient studies have produced equivocal results on the relation of vitamins A and E to prostate cancer risk. To evaluate this association further, we conducted a nested case-control study in a cohort of 6860 Japanese-American men examined from 1971 to 1975. At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of more than 20 years, 142 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 142 matched controls were measured by high-performance liquid chromatography for the following: total carotenoids, lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, total retinoids, retinol, total tocopherols, alpha-tocopherol, delta-tocopherol, and gamma-tocopherol. Odds ratios for prostate cancer, based on quartiles of serum micronutrient levels, were determined using conditional logistic regression analysis. The odds ratio for the highest quartiles were 1.8 (95% confidence interval, 0.9-3.9) for beta-cryptoxanthin, 1.6 (0.8-3.5) for beta-carotene, 0.8 (0.4-1.5) for retinol, and 0.7 (0.3-1.5) for gamma-tocopherol, but none of the differences was statistically significant. For the other micronutrients, the results were also unremarkable. The findings of this study indicate that none of the micronutrients is strongly associated with prostate cancer risk.


Subject(s)
Asian , Feeding Behavior , Micronutrients/adverse effects , Prostatic Neoplasms/epidemiology , Aged , Carotenoids/adverse effects , Carotenoids/analysis , Causality , Cohort Studies , Cross-Sectional Studies , Follow-Up Studies , Hawaii/epidemiology , Humans , Incidence , Male , Micronutrients/analysis , Middle Aged , Odds Ratio , Population Surveillance , Prostatic Neoplasms/blood , Prostatic Neoplasms/etiology , Risk Factors , Vitamin A/adverse effects , Vitamin A/analysis , Vitamin E/adverse effects , Vitamin E/analysis
17.
Cancer Epidemiol Biomarkers Prev ; 6(6): 407-12, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9184773

ABSTRACT

Numerous dietary studies have found that vegetables and fruits protect against upper aerodigestive tract cancer. To evaluate the role of beta-carotene and other specific carotenoids, a nested case-control study using prediagnostic serum was conducted among 6832 American men of Japanese ancestry examined from 1971 to 1975. During a surveillance period of 20 years, the study identified 28 esophageal, 23 laryngeal, and 16 oral-pharyngeal cancer cases in this cohort. The 69 cases were matched to 138 controls. A liquid chromatography technique, designed to optimize recovery and separation of the individual carotenoids, was used to measure serum levels of lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, retinol, retinyl palmitate, and alpha-, delta-, and gamma-tocopherol. With adjustment for cigarette smoking and alcohol intake, we found that alpha-carotene, beta-carotene, beta-cryptoxanthin, total carotenoids and gamma-tocopherol levels were significantly lower in the 69 upper aerodigestive tract cancer patients than in their controls. Trends in risk by tertile of serum level were significant for these five micronutrients. These significant trends persisted in cases diagnosed 10 or more years after phlebotomy for the three individual carotenoids and total carotenoid measurements. The odds ratios for the highest tertile were 0.19 (95% confidence interval, 0.05-0.75) for alpha-carotene, 0.10 (0.02-0.46) for beta-carotene, 0.25 (0.06-1.04) for beta-cryptoxanthin, and 0.22 (0.05-0.88) for total carotenoids. When the cases were separated into esophageal, laryngeal, and oral-pharyngeal cancer, both alpha-carotene and beta-carotene were consistently and strongly associated with reduced risk at each site. The findings suggest that alpha-carotene and other carotenoids, as well as beta-carotene, may be involved in the etiology of upper aerodigestive tract cancer.


Subject(s)
Diet/adverse effects , Esophageal Neoplasms/blood , Laryngeal Neoplasms/blood , Pharyngeal Neoplasms/blood , Trace Elements/blood , Aged , Case-Control Studies , Chromatography, High Pressure Liquid , Esophageal Neoplasms/ethnology , Fruit , Hawaii , Humans , Japan/ethnology , Laryngeal Neoplasms/ethnology , Male , Middle Aged , Pharyngeal Neoplasms/ethnology , Prospective Studies , Trace Elements/deficiency , Vegetables
18.
Cancer Epidemiol Biomarkers Prev ; 6(12): 1087-93, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9419408

ABSTRACT

Black patients with colon cancer in the Black/White Cancer Survival Study were found to have a poorer survival than white patients. More advanced-stage disease at diagnosis was the primary determinant, accounting for 60% of the excess mortality. After adjusting for stage, factors such as poverty, other socioeconomic conditions, and treatment did not further explain the remaining survival deficit. This study examined the aggressiveness of colon tumors in blacks and whites to explore its role in the racial survival differences. Tumor characteristics of 703 cases of newly diagnosed invasive colon adenocarcinoma were centrally evaluated by a gastrointestinal pathologist, blinded in regard to the age, race, and sex of the patients. Blacks were less likely to have poorly differentiated (grade 3) tumors [odds ratio (OR), 0.44; 95% confidence interval, 0.22-0.88] and lymphoid reaction (OR, 0.49; 95% confidence interval, 0.26-0.90) when compared with whites. These black/white (B/W) differences remained statistically significant after adjusting for age, sex, metropolitan area, summary stage, socioeconomic status, body mass index, and health care access and utilization. In addition, blacks were less likely to have high-grade (grade 3) nuclear atypia, mitotic activity, and tubule formation, although these ORs did not reach a statistical significance level of 0.05. Similar B/W differences were observed for patients with advanced disease but not with early stage. Comparison by anatomical subsite showed that blacks had statistically significantly better differentiated tumors for cancers of the proximal and transverse colon but not for the distal. No racial differences were found for blood vessel and lymphatic invasion, necrosis, fibrosis, and mucinous type of histology. The findings, therefore, are the opposite of those hypothesized. After adjusting for stage, more aggressive tumor characteristics do not explain the adverse survival differential in blacks. This suggests that there may be racial differences in environmental exposure, and that the intensity and mode of delivery of carcinogen insult as well as host susceptibility may differ by race and anatomical subsite. Future studies should explore the B/W differences in tumor biology using molecular markers that precede the conventional histological parameters evaluated here.


Subject(s)
Black or African American , Carcinoma/pathology , Colonic Neoplasms/pathology , White People , Adult , Black or African American/statistics & numerical data , Aged , Carcinoma/epidemiology , Carcinoma/ethnology , Carcinoma/etiology , Carcinoma/mortality , Colonic Neoplasms/epidemiology , Colonic Neoplasms/ethnology , Colonic Neoplasms/etiology , Colonic Neoplasms/mortality , Disease Progression , Female , Humans , Male , Middle Aged , Neoplasm Staging , Odds Ratio , Socioeconomic Factors , White People/statistics & numerical data
20.
Cancer Epidemiol Biomarkers Prev ; 5(8): 621-5, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8824364

ABSTRACT

It is suspected that male hormones are associated with the risk of prostate cancer. To test this hypothesis, we conducted a nested case-control study in a cohort of 6860 Japanese-American men examined from 1971 to 1975. At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of more than 20 years, 141 tissue-confirmed incident cases of prostate cancer were identified, and their stored sera and those of 141 matched controls were assayed for total testosterone, free testosterone, dihydrotestosterone, 3-alpha-androstanediol glucuronide, androsterone glucuronide, and androstenedione. Odds ratios for prostate cancer, based on quartiles of serum hormone levels, were determined using conditional logistic regression methods. The odds ratios for the highest quartiles were 1.37 (95% confidence interval, 0.73-2.55) for 3-alpha-androstanediol glucuronide and 1.24 (95% confidence interval, 0.62-2.47) for androstenedione, but none of the differences was statistically significant. The results were unremarkable for the other four hormonal measurements. In addition, the patients and controls were compared by hormonal ratios (i.e., total testosterone:dihydrotestosterone), but the results were also unremarkable. The findings of this study indicate that none of these androgens is strongly associated with prostate cancer risk.


Subject(s)
Androgens/blood , Neoplasms, Hormone-Dependent/blood , Prostatic Neoplasms/blood , Aged , Analysis of Variance , Asian , Case-Control Studies , Humans , Logistic Models , Male , Middle Aged , Proportional Hazards Models , Prostatic Neoplasms/ethnology , Risk Factors
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