Does gastrointestinal Candida albicans prevent ubiquinone absorption?

Ubiquinones (coenzyme Qs (CoQ)) are essential for oxidative phosphorylation in yeasts and humans, although the isomers present in each are different. The human coenzyme Q, CoQ10, is administered orally for the treatment of heart disease and other disorders. Some patients, however, require much higher doses than others to attain a therapeutic CoQ10 blood level. We propose that one possible explanation for this variability is Candida colonization of the GI tract. Many common medical treatments including antibiotics and anti-hyperchlorhydric agents increase the risk of GI tract Candida colonization. Subsequent uptake and utilization of supplemental CoQ10 by the yeast could diminish availability for the human subject. Data from one patient and an in vitro pilot study using two pathogenic strains of C. albicans support this hypothesis. If C. albicans in the GI tract can hinder availability and interfere with therapeutic effects of CoQ10, it could be of clinical significance for large numbers of patients.

Cadmium in zinc-containing mineral supplements.

Seven zinc-containing dietary supplements were analyzed for zinc (Zn) and cadmium (Cd) by inductively coupled plasma/mass spectrometry (ICP/MS). Cadmium was detected in all samples; however, the amount of Cd per 15 mg Zn (the daily US Recommended Dietary Allowance) varied by over 37-fold (0.039 to 1.46 micrograms Cd/15 mg Zn). Supplements with Zn in the form of a gluconate consistently contained the lowest amounts of Cd. Because Cd is a non-essential potentially toxic element for humans, its concentration in nutritional supplements should be minimized and possibly regulated by government-established standards.

Organochlorines in stranded pilot whales (Globicephala melaena) from the coast of Massachusetts.

Pilot whales strand periodically along the U.S. coast, and these strandings offer an opportunity for the collection of tissues for biomonitoring of contaminant exposure in cetaceans, as well as for specimen archiving. Concentrations of organochlorine (OC) contaminants (e.g., PCB congeners, pesticides, DDTs) were measured in tissue samples from pilot whales that stranded in 1986 and 1990 along the Massachusetts coast. Adult and fetal samples of blubber, liver, brain, and kidney were collected, as well as ovaries from mature female whales. Many of the OCs found in maternal tissues were detected in corresponding fetal tissues indicating maternal transfer of OCs to the fetus. The concentrations of individual OCs in tissues varied considerably among the animals. Statistically significant differences were found between females and males for the concentrations of certain analytes (e.g., SigmaPCBs, p,p'-DDE) and these differences may be partially due to contaminants being transferred by the female whales during gestation and lactation. The concentrations of OCs in different tissues were similar when based on total lipid weight, except for the brain, which contained the lowest lipid-normalized OC concentrations. The low concentrations in brain may be related to the disparate lipid compositions in this tissue as well as the presence of the blood-brain barrier. The availability of data on these archived and biomonitoring samples provides a baseline for future retrospective studies.

Chemical contaminants in harbor porpoise (Phocoena phocoena) from the north Atlantic coast: tissue concentrations and intra- and inter-organ distribution.

Concentrations of chlorinated hydrocarbons (CHs), such as polychlorinated biphenyls (PCBs), were measured in subsamples taken from different anatomical locations of blubber and liver of three apparently healthy harbor porpoises (Phocoena phocoena) incidentally caught in a gill-net fishery along the northwest Atlantic coast; selected elements (e.g., mercury) were measured in subsamples of liver. The vertical distribution (skin to muscle) of contaminants within blubber was also determined. Additionally, the concentrations of CHs and elements were determined in individual samples of brain, lung, kidney, and testis to assess how the disposition of toxic chemicals may be dependent on the physiological characteristics of a specific organ. Statistical analyses of the results showed that the anatomical location of the blubber or liver sample had no significant effect on concentrations of either CHs in blubber and liver, or of selected elements in liver. However, there were statistical differences between strata of blubber (skin to muscle) for the concentrations of CHs. As expected, the results showed that the CH concentrations, based on wet weight, were considerably higher in the blubber than in the other tissues; however, the concentrations of CHs in the different tissues were more comparable when values were based on total lipid weight with the exception of the brain where lipid normalized concentrations were lower than in all other tissues: This low relative accumulation of lipophilic contaminants in the brain tissue may be due to the presence of the blood-brain barrier, or due to a lower proportion of neutral lipids, such as triglycerides, as analysis for percent lipid and for the proportion of specific lipid classes showed.

Butyltin contamination of sediments and benthic fish from the East, Gulf and Pacific coasts of the United States.

Butyltin concentrations were determined in sediments, tissues and stomach contents of fish collected in 41 embayments on the East, Gulf and Pacific coasts of the U.S.A. between 1986 and 1991 as part of the National Oceanic and Atmospheric Administration's (NOAA) National Benthic Surveillance Project (NBSP). A total of 99 sediments, 108 fish liver samples from 11 fish species, and 10 composites of fish stomach contents were analyzed for tetrabutylin, tributylin, dibutylin and monobutylin. Tributyltin (TBT) was detected (i.e. > 10 ng/g) in 38 of the sediments samples analyzed and was generally the predominant bulytin present; concentrations of total butyltins ranged from 15 to 1600 ng/g wet weight. The highest concentrations were found in sediments from urban sites, especially sites on the West coast. Many of the fish liver and stomach contents samples also contained butyltins. Tributyltin represented 83 (7.1)% [mean (SEM); n=15], 64 (6.6)% (n=12) and 36 (7.8)% (n=12) of the total butyltins in livers from white croaker, winter flounder and Atlantic croaker, respectively, suggesting possible species differences in biotransformation of TBT. The concentrations of butyltins in stomach contents indicated that diet can be a significant route of exposure of fish to butyltins. Between 1986 and 1991 butyltin concentrations in sediments and fish generally appeared to be declining; however, no statistically significant temporal trends were observed at individual sites or for the sites overall.

Mutagen formation during commercial processing of foods.

Levels of bacterial mutagenicity 3-17 times above spontaneous are generated during commercial thermal processing (canning) of foods, particularly foods high in protein. The potential for other processing operations, including pasteurization, dehydration, and concentration, to produce substances active in the Ames Salmonella assay was also examined. Two heated fish model systems, canned salmon and fried sole, were established by extracting mutagen precursors from fish tissues with water. The model system studies suggest that the limiting reactants for mutagen formation differ from one food product to another, and that Maillard type browning reactions are involved in mutagen production. Bisulfite treatment was found to inhibit mutagen formation in modal systems and whole food products. Isolation and partial characterization of the mutagens in both fried and canned pink salmon showed that at least three distinct mutagens were present. These mutagens exhibited HPLC retention time patterns on C18, cyano, and amino columns different than the major mutagens present in other cooked and grilled meats and fish.

Toxic chemicals in sediments and biota from a creosote-polluted harbor: relationships with hepatic neoplasms and other hepatic lesions in English sole (Parophrys vetulus).

High prevalences of idiopathic hepatic lesions, including neoplasms (e.g., hepatocellular carcinomas, cholangiocellular carcinomas) (27%, 20 of 75 fish) and foci of cellular alteration (putative 'preneoplastic' lesions) (44%, 33 of 75 fish), were found in English sole (Parophrys vetulus) exposed to creosote-contaminated sediments in Eagle Harbor, Puget Sound, WA. Sediments from the contaminated region of the harbor contained particularly high concentrations of aromatic hydrocarbons (e.g., benzo[a]pyrene and benz[a]anthracene), and a variety of nitrogen-containing aromatic compounds (e.g., carbazole and acridine). The composition of the aromatic compounds was characteristic of creosote. Dramatically lower concentrations of aromatic compounds were found in sediments from a reference site in which the bottom-dwelling fish examined were free of detectable neoplastic or 'preneoplastic' hepatic lesions. Food organisms in the stomachs of the English sole from Eagle Harbor contained substantially higher concentrations of aromatic hydrocarbons than comparable organisms from the reference site. The concentrations of individual aromatic hydrocarbons in muscle and liver from the Eagle Harbor fish were low; however, high concentrations of metabolites of aromatic compounds were present in the bile. The findings strongly suggest an association between exposure to creosote and the prevalence of hepatic lesions, including neoplasms, in the bottom-dwelling fish, and furthermore support the putative role of aromatic hydrocarbons in liver carcinogenesis in fish.

Occurrence of mutagens in canned foods.

Mutagens are shown to be present in a variety of commercially heat-processed foods. Since these substances are not present in the unheated raw material, it appears that they are produced during processing. Canned salmon and beef broth showed the highest mutagenicity while other canned beef and fish products yielded lower but detectable levels. These findings are significant not only because of the large proportion of the food supply which is processed by canning, but also because the mutagens in these foods exhibit chemical behaviors and Salmonella strain specificity similar to mutagens in grilled foods which have been shown to be mammalian carcinogens.

Mutagen formation during the cooking of fish.

Compounds mutagenic toward Salmonella typhimurium strains sensitive to frameshift mutation (1537, 1538 and TA98) were formed when fish flesh was fried at 190 degrees c. Four species of marine fish commonly consumed in the United States were cooked in an electric skillet and broiled beneath the elements of an electric oven. Organic extracts of the fish were tested in the Salmonella mutagenic assay using strains 1535, 1537, 1538, TA98 and TA100. Basic organic extracts of fried but not raw or broiled samples exhibited significant mutagenicity with metabolic activation. Mutagenic activity ratios ranging from 3.3 to 15.7 for the extract from 20 g of fish were observed. The mutagenicity produced during the frying of fish was dependent on time. Frying times of less than 6 min produced no mutagenic activity, while at 6 min or greater substantial mutagenicity was generated.

Effect of pH and ammonium ions on mutagenic activity in cooked beef.

Controversy surrounding the extraction procedure commonly used for isolating and concentrating mutagens from foods has resulted in a need for the re-examination of the reported mutagenicity in fried hamburgers. Using a procedure in which Na2SO4 and NaOH are substituted for (NH4)2SO4 and NH4OH respectively, mutagenic activity in extracts of hamburgers fried for 5 min appeared to be unchanged. However, when organic extractions are performed at pH conditions more moderate than those generally employed to isolate mutagens from foods, a 30-50% decrease in mutagenicity is observed.

A source of error in mutagen testing of foods.

Mutagenic compounds reported to be present in foods may be forming during the extraction process rather than during cooking or baking. In this study, the formation of mutagenic substances in biscuits was examined using in the extraction procedure either ammonium sulfate and ammonium hydroxide or sodium sulfate and sodium hydroxide. Compounds producing high mutagenic activity in Salmonella strains 1538 and TA 98 obtained from aqueous biscuit extracts containing ammonium ions. No mutagenic activity was observed in extracts from aqueous biscuit extracts containing sodium ions until some ammonium ions (NH4OH) were added. We suggest that ammonium sulfate and ammonium hydroxide not be used in the extraction procedure of food when studying mutagen formation.