Chlorinated hydrocarbon solvents: Substituting our way toward human carcinogenicity

A discussion of the history of substitutions in industrial solvent use is presented, and animal carcinogenicity studies with certain chlorinated hydrocarbon solvents are reviewed. The present knowledge on the association between occupational exposure to chlorinated hydrocarbon solvents and human carcinogenicity is summarized, including a critical review of 23 studies pertaining to human carcinogenicity. Several deficiencies are identified in these studies that make interpretation of the results uncertain, including poor characterization of exposures in qualitative and quantitative terms, the small numbers of deaths or cases, and short follow-up periods. Despite these weaknesses, we conclude that, when viewed collectively, the evidence strongly suggests that occupational exposures to chlorinated hydrocarbon solvents are associated with an excess human cancer risk. The literature supports an association between occupational exposures to chlorinated hydrocarbons and elevated risks of leukemia, lymphoma, and urinary tract cancer. Parental occupational exposures are consistently associated with an elevated childhood cancer risk in the offspring. © 1993 Wiley-Liss, Inc.     

Relationship between levels of chlorinated hydrocarbon insecticides in human milk and serum

Summary Simultaneous chlorinated hydrocarbon insecticide analyses were performed on milk and serum from twentyeight lactating women living in three widely scattered cities in Texas. No correlation could be established between milk and serum levels of p,p-DDE, p,p-DDT, dieldrin, or BHC. It was concluded that breast milk insecticide levels do not have the epidemiologic significance that the serum levels suggest.     

Chlorinated hydrocarbon solvents and biliary-pancreatic cancer: Report of three cases

This paper describes three men, aged 45 years or younger, who developed cholangio, ampullary, and pancreatic cancer after prolonged heavy exposure to trichlorinated hydrocarbon solvents. Two of these patients had exposure to other potential carcinogens, and one had a strong family history of cancer. The association between chlorinated hydrocarbons and biliary-pancreatic cancer has also been suggested by other reports in the recent literature. Exposure to trichlorinated hydrocarbon solvents is a risk factor for the development of biliary and pancreatic cancer. © 1996 Wiley-Liss, Inc.     

Chlorinated hydrocarbon insecticide residues in tennessee honey and beeswax

Several samples of commercial grade honey collected from different parts of Tennessee during the summer of 1973 were analyzed for chlorinated hydrocarbon insecticide (CHI) residues. A Modified Mill's Procedure was used to cleanup the samples prior to gas Chromatographic analysis using electron capture (EC) detection. The presence of CHI residues was confirmed by analysis on three different columns of widely varying polarity. Most of the samples contained CHI residues at 0.01—0.30 parts per billion (ppb) level. Beeswax produced during the same season contained several times higher levels of the residue than the honey samples. Recoveries of CHI residues varied from 81–95 percent by the procedure employed.     

Evaluation of fasting serum insulin levels among Japanese school-age children

We examined the physical constitution, serum lipids, fasting serum insulin (IRI), food intake, and physical activity in 1,330 children in three age groups (6-7, 9-10, and 12-13) in Nagao village for the period 1994-1996. Serum total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) levels were positively correlated, and HDL-C and TG were negatively correlated in all age groups. IRI was significantly higher among the elder children, and it was also higher in girls than in boys. IRI was positively correlated with the body mass index (BMI) and triceps skinfold thickness in ages 9-10 and 12-13, but no significant correlation was noted with waist/hip ratio (W/H ratio). In ages 12-13, IRI was positively correlated with TC and TG and negatively correlated with HDL-C. In high-IRI children (above 11.4 microU/mL) ages 12-13, the high-fat diet (fat-energy ratio above 30%) and low physical activity children (physical activity score below 10 points) were more frequent, and the mean levels of triceps skinfold were higher. The positive correlation between TC and HDL-C was not significant among high-IRI children. We concluded that a high-fat diet, low physical activity, and body fat accumulation influence the IRI level, which is closely related to serum lipid levels.     

Effects of feeding oyster,Crassostrea gigas,on serum and liver lipid levels in rats

The effects of feeding dietary and defatted oyster meat on lipid metabolism were investigated in rats by comparing measurements with those of casein and soybean protein. In the first experiment, male rats were fed 0.1% and 1% cholesterol-supplemented diets containing casein, oyster or soybean protein under the same dietary level of protein (20%). The concentrations of serum and liver cholesterol in the oyster group were significantly lower than those in the casein group for both the 0.1% and 1% cholesterol-supplemented diets. The cholesterol-lowering effect of oyster meat was more predominant than that of soybean protein. Feeding oyster meat significantly decreased the serum triglyceride concentration as compared to feeding casein for the 0.1% cholesterol-supplemented diets, and it reduced hepatic triglyceride concentration in both groups fed the 0.1% and 1% cholesterol-supplemented diets. The excretion of fecal total steroids was higher in the rats fed oyster meat than those fed casein or soybean protein for both the 0.1% and 1% cholesterol-supplemented diets. In the second experiment, the effects of defatted oyster on lipid metabolism were compared with casein and soybean protein in diets supplemented with cholesterol. The serum cholesterol concentration in the defatted oyster group was comparable to that in the other two groups, but the ratio of high-density lipoprotein-cholesterol to total cholesterol was higher in the defatted oyster group. The feeding of defatted oyster induced a lower liver cholesterol concentration as compared to casein and soybean protein. Serum and liver triglyceride levels were lower in the defatted oyster group than in the casein group. Defatted oyster accelerated the fecal excretion of both neutral and acidic steroids as compared to casein. Our results suggest that the feeding of oysters exerts a more potent hypolipidemic activity than soybean protein, and the effect may be ascribed to both lipid and non-lipid fractions in oyster.     

Effects of dietary fat quantity and composition on fasting and postprandial levels of coagulation factor VII and serum choline-containing phospholipids

Dietary fat influences plasma levels of coagulation factor VII (FVII) and serum phospholipids (PL). It is, however, unknown if the fat-mediated changes in FVII are linked to PL. The present study aimed to investigate the effects of dietary fat on fasting and postprandial levels of activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII protein (FVIIag) and choline-containing PL (PC). In a randomized single-blinded crossover-designed study a high-fat diet (HSAFA), a low-fat diet (LSAFA), both rich in saturated fatty acids, and a high-fat diet rich in unsaturated fatty acids (HUFA) were consumed for 3 weeks. Twenty-five healthy females, in which postprandial responses were studied in a subset of twelve, were included. The HSAFA diet resulted in higher levels of fasting FVIIa and PC compared with the LSAFA and the HUFA diets (all comparisons P< or =0.01). The fasting PC levels after the LSAFA diet were also higher than after the HUFA diet (P<0.001). Postprandial levels of FVIIa and PC were highest on the HSAFA diet and different from LSAFA and HUFA (all comparisons P< or =0.05). Postprandial FVIIa was higher on the HUFA compared with the LSAFA diet (P<0.03), whereas the HUFA diet resulted in lower postprandial levels of PC than the LSAFA diet (P<0.001). Significant correlations between fasting levels of PC and FVIIc were found on all diets, whereas FVIIag was correlated to PC on the HSAFA and HUFA diet. The present results indicate that dietary fat, both quality and quantity, influences fasting and postprandial levels of FVIIa and PC. Although significant associations between fasting FVII and PC levels were found, our results do not support the assumption that postprandial FVII activation is linked to serum PC.     

Continuous nasoenteral feeding: inverse relation between infusion rate and serum levels of bilirubin

The relation between nasoenteric formula caloric infusion rate and the serum bilirubin level was examined in 15 healthy subjects. The study protocol spanned 3 days and included fasting studies on day 1, continuous maintenance nasogastric feeding of a formula diet on day 2, and continuous feeding at a rate twice the maintenance level on day 3. Blood studies were performed in the early morning of each day. Fifteen subjects underwent the fasting measurements and the maintenance infusion, while 11 underwent all 3 days of the protocol. With the maintenance infusion serum bilirubin fell from the fasting value of (X +/- SD) 0.77 +/- 0.53 to 0.63 +/- 0.49 mg/dl for a reduction of 18% (p less than 0.05). For the subgroup of 11 subjects receiving two levels of formula infusion, fasting and maintenance serum bilirubin levels were 0.81 +/- 0.57 and 0.65 +/- 0.47 mg/dl, respectively, (p less than 0.05). With the twice maintenance infusion the plasma bilirubin decreased further to 0.46 +/- 0.29 mg/dl, a decrement of 43% relative to fasting (p less than 0.01). No other significant changes were detected during the protocol in the standard blood chemical and hematologic studies. Thus, the serum level of bilirubin is inversely related to the formula caloric infusion rate during continuous nasoenteric feeding.