Is gastric cancer part of the tumour spectrum of hereditary non-polyposis colorectal cancer? A molecular genetic study.

BACKGROUND: Gastric cancer is the second most common extracolonic malignancy in individuals with hereditary non-polyposis colorectal cancer (HNPCC)/Lynch syndrome. As gastric cancer is relatively common in the general population as well, it is not clear whether or not gastric cancer is a true HNPCC spectrum malignancy. AIM: To determine whether or not gastric cancer is a true HNPCC spectrum malignancy. SUBJECTS AND METHODS: The molecular and clinicopathological profiles of gastric cancers (n = 13) from HNPCC mutation carriers were evaluated and compared with the profiles of sporadic gastric cancers (n = 46) stratified by histology and microsatellite instability (MSI) status. RESULTS: This study on sporadic and HNPCC gastric cancers revealed several important universal associations. Loss of heterozygosity in the adenomatous polyposis coli (APC) region was associated with intestinal histology regardless of the MSI (p = 0.007). KRAS-mutations (p = 0.019) and frameshift mutations in repeat tracts of growth-regulatory genes (p<0.001) were associated with MSI tumours being absent in microsatellite stable (MSS) tumours. The average number of methylated tumour suppressor gene loci among the 24 genes studied (methylation index) was higher in MSI than in MSS tumours regardless of histology (p<0.001). Gastric cancers from HNPCC mutation carriers resembled sporadic intestinal MSI gastric cancers, except that MLH1 promoter methylation was absent (p<0.001) and the general methylation index was lower (p = 0.038), suggesting similar, but not identical, developmental pathways. All these lacked the mismatch repair protein corresponding to the germline mutation and displayed high MSI. CONCLUSION: The present molecular evidence, combined with the previous demonstration of an increased incidence relative to the general population, justify considering gastric cancers as true HNPCC spectrum malignancies.

Gramine and free amino acids as indicators of fluoride-induced stress in barley and its consequences to insect herbivory.

Barley leaves were sprayed with aqueous NaF, which caused accumulation of fluoride in the foliage, but no visible symptoms were detectable. No significant correlation was observed between foliar fluoride concentration and content of the indole alkaloid gramine after exposure to fluoride levels of 20 to 60 mg F liter-1. Fluoride exposure did not explicitly affect the performance of Carausius morosus or Rhopalosiphum paid on barley. After exposure to fluoride levels of 100 and 200 mg F liter-1, as NaF, fluoride treatment had a significant effect on gramine concentration of the first leaf of barley, being highest at a fluoride treatment of 200 mg liter-1, and there was a slight, but significant positive correlation between the log-transformed foliar fluoride concentration and log-transformed gramine concentration of the first leaf. Fluoride treatment increased levels of some individual free amino acids in barley foliage. Exposure of young barley to NaF in aqueous form caused accumulation of fluoride in barley foliage and resulted in increased levels of gramine in the first leaf and levels of some free amino acids in foliage. It is possible that the fluoride-induced concurrent increase in gramine concentration in barley leaves could override the eventual increase in nutritive value to herbivorous insects after fluoride exposure. More detailed biochemical studies of the induction of gramine production are needed to understand the fluoride effects in secondary metabolism of barley.

Deposition of motor vehicle emissions and winter maintenance along roadside assessed by snow analyses.

A vertical snow-sampling method, where a sample was taken throughout the snowpack, was used to estimate the pollutant load on a roadside where average daily traffic density was about 9100 motor vehicles. The snow samples were collected at two sites, forest and open field, at two distances of 10 and 30 m from the road. The concentrations of inorganic anions (Cl(-), NO(-)(3), SO(2-)(4)), total N, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated phenols (PCPhs) were analysed. The results suggest that on roadsides there is a deposition caused by road traffic emissions and winter maintenance which exceeds normal background deposition. Inorganic anions mainly in particle form, originating from winter maintenance, are deposited near the road. PAHs with low molecular weight (

On the Relationships of Net CO(2) Assimilation and Leaf Expansion to Vegetative Growth in Lycospersicum esculentum, var Jubilee.

Relationships between net plant CO(2) exchange rate (CER) and canopy development were examined in ;jubilee' tomato over the initial 4 weeks of vegetative growth. A comparison was made between two plant groups that were alternatively exposed to 200 or 800 microeinsteins per square meter per second midday irradiation to establish a differential in net CER. Plants exposed to higher irradiation demonstrated a 2- to 4-fold greater net photosynthetic rate per leaf area and 100% average higher net CO(2) assimilation rate/plant. day. However, leaf-stem growth differed by <50% suggesting a poor relationship to CER. Leaf area growth rate (LAGR) of individual leaves appeared closely related to CER during initial leaf expansion but a greater function of order of emergence in successive leaf growth. LAGR on a per plant basis increased linearly with leaf dry weight but appeared more limited by factors determining maximum leaf enlargement and rate of new leaf development. Net CO(2) assimilation/leaf area and leaf starch consistently declined with time while net CO(2) assimilation plant/day approached a constant rate following 2 to 3 weeks growth. Composite results suggested a simple relationship for sucessive growth where accumulated leaf carbohydrate in excess of 200 milligrams/plant.day could be expected to be partitioned to other plant segments.

Odor as an aid to chemical safety: odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution.

The body of information in this paper is directed to specialists in industrial health and safety, and air and water pollution, who need quantitative data on the odor thresholds of potentially hazardous chemical vapors and gases. The literature, largely unorganized, has been reviewed for 214 compounds and condensed into tables based on consistent units. Data on the volatility, solubility, ionization and water-air distribution ratio at 25 degrees C are included. From the currently recommended threshold limit value (TLV), a safe dilution factor and an odor safety factor are calculated for each compound. The equivalent data are presented for both air and water dilutions of the chemicals. Available data are summarized on the variability of odor sensitivities in the population, and the increased odor concentrations that are required to elicit responses from persons whose attention is distracted, or who are sleeping. This information is reduced to calibration charts that may be used to estimate the relative detectability, warning potential and rousing capacity of the odorous vapors. Each compound has been assigned a letter classification, from A to E, to indicate the margin of safety, if any, that may be afforded by the odor of the compound as a warning that its threshold limit value is being exceeded.

Relationships among crude fiber, neutral detergent fiber, in vitro dietary fiber, and in vivo (rats) dietary fiber in wheat foods.

The in vivo dietary fiber contents of wheat milling fractions and wheat foods, determined in rat feeding experiments, were compared with dietary fiber values determined in vitro with pronase alpha-amylase digestion. Both types of dietary fiber values were compared with crude fiber and neutral detergent fiber values in the same materials. Regression analyses indicated close correlation amongst all values determined. It appears that laboratory analysis for crude fiber, neutral detergent fiber, or in vitro dietary fiber accurately predicts in vivo dietary fiber (rats) for wheat milling fractions when the laboratory result is adjusted by means of an appropriate regression equation.