Spontaneous ovarian choriocarcinoma in a young ICR mouse

This paper describes the spontaneous ovarian choriocarcinoma observed in a young female Crl:CD1 (ICR) mouse. The mouse was sacrificed at 8 weeks of age after oral administration of a compound for 2 weeks. The left ovary was found to be cystically enlarged with dark red hemorrhaging. The cystic mass contained abundant blood plasma and erythrocytes. At the peripheral regions of the mass, large pleomorphic tumor cells with bizarre shaped nuclei were detected. Tumor cells contained a single large nucleus and abundant eosinophilic to amphophilic cytoplasm. Histopathology of the tumor cells resembled that of trophoblastic giant cells. Therefore, the observed ovarian lesion was diagnosed as a choriocarcinoma. No microscopic lesions were observed in the right ovary or other reproductive organs. Ovarian choriocarcinoma was considered to be of non-gestational origin. This is the first report of ovarian choriocarcinoma in a young ICR mouse.     

Determination of acetamiprid,imidacloprid, and nitenpyram residues in vegetables and fruits by high-performance liquid chromatography with diode-array detection

Determination of 3 neonicotinoid insecticides, nitenpyram, imidacloprid, and acetamiprid, was studied. Vegetables and fruits were extracted with acetonitrile. The crude extract was passed through a weak anion-exchange cartridge (PSA). The effluent was subjected to silica gel cartridge. Imidacloprid and acetamiprid were eluted with 10 mL of 4:6 (v/v) acetone/hexane, followed by nitenpyram with acetone (20 mL). Pesticides were determined by HPLC with a C-18 column and diode-array detection system. Imidacloprid and acetamiprid were recovered at about 90% at the spike levels with 0.2 and 2 mg/kg in cucumber, potato, tomato, eggplant, Japanese radish, and grape. Nitenpyram was recovered at 64-80%. Relative standard deviations were less than 10% throughout all the recovery tests. In the residue analysis, agriculturally incurred pesticides at 0.08-0.14 mg/kg were designated with UV spectra compared with respective reference standards.     

Simultaneous liquid chromatographic determination of water-soluble vitamins, caffeine, and preservative in oral liquid tonics

A rapid, simple, and reliable liquid chromatographic method has been developed for the simultaneous determination of nicotinamide (niacinamide), thiamine, riboflavin, riboflavin sodium phosphate, pyridoxine, caffeine, and sodium benzoate in commercial oral liquid tonics. The 7 components are separated on a reverse phase C18 column using a mobile phase of acetonitrile-0.01M potassium dihydrogen phosphate-triethylamine (8 + 91.5 + 0.5 v/v/v) containing 5mM sodium octanesulfonate and adjusted to pH 2.8 with phosphoric acid. Components are detected at 254 nm with attenuation 0.02 AUFS. Acetanilide is used as an internal standard. In addition to the 7 components mentioned, nicotinic acid (niacin), cyanocobalamin, and folic acid are also separated under the same conditions. Sample preparation involves only addition to internal standard solution and dilution with mobile phase and then filtration. Recoveries of the 7 components and cyanocobalamin from spiked preparations ranged from 97 to 104% with coefficients of variation of 0.9-4.2%.     

Novel approach for large-scale, biocompatible, and low-cost fractionation of peptides in proteolytic digest of food protein based on the amphoteric nature of peptides

A large-scale, biocompatible, and low-cost procedure for peptide fractionation based on the amphoteric nature of peptide is developed. A sample cell (120 x 100 x 50 mm) with four joint tubes (17 mm i.d. and 20 mm in length) on the front and back was prepared. On the end of the joint tubes, a nylon screen (100 mesh)-supported agarose gel layer was formed. Five or nine of the sample cells were connected. A tryptic digest of casein (2.0-3.6 L) was applied to the sample cells. At each end of the sample cell apparatus, an additional cell filled with 0.1 M H(3)PO(4) or NaOH was connected and used as anode and cathode compartments, respectively. Reproducible fractionation of peptide could be achieved by collecting fractions with specific pH values when voltage reached a plateau by applying direct current at constant power. Running time necessary for fractionation of peptide was inversely proportional to electric power and directly proportional to sample volume.     

Proton Budget for a Japanese Cedar Forest Ecosystem

The proton budget for a Japanese cedar (Cryptomeria japonica) forest in Gunma Prefecture, Japan, was studied by estimating biogeochemical fluxes. The proton budgets were estimated for three individual compartments of the ecosystem: vegetation canopy, and the upper (O horizon + 0–10 cm) and lower (10–100 cm) soil layers. The dominant proton sources in the compartments were atmospheric deposition (1.2 kmol ha^?1 yr^?1), nitrification (5.1 kmol, ha^?1 yr^?1) and base-cation uptake by vegetation (8.0 kmol, ha^?1 yr^?1) respectively. These proton sources were neutralized almost completely within the individual compartments mainly by base-cation release from the canopy or the soil. The sum of internal proton sources was five times as large as that of external ones. Nitrogen input from the atmosphere was 2.2 kmol ha^?1 yr^?1, whereas its output from the lower soil layer was 3.9 kmol ha^?1 yr^?1, indicating that a net loss of nitrogen occurred in the ecosystem. However, this did not cause the acidification of soil leachates because of a sufficient release rate of base cations from the soil.     

Degradation and metabolism of a fungicide, 2,4,5,6-tetra-chloroisophthalonitrile (TPN) in soil

Summary Degradation of a fungicide, 2,4,5,6-tetrachloroisophthalonitrile (TPN) in soil was studied under laboratory conditions. TPN degraded more rapidly under 60% WHC conditions than at 20%, 40% and 100% WHC, while its degradation was rapid at temperatures of 25°C-30°C, evidently due to the microbial degradation. TPN degraded mainly through dechlorination and partly a substitution reaction. The degradation products identified by gas chromatographic analyses were: 2,4,5-trichloroisophthalonitrile (abbreviated as 2,4,5-Cl₃-IPN), 2,4,6-Cl₃-IPN, 2,4-Cl₂-lPN, 2,5-Cl₂-IPN, 4-Cl-IPN, 5-Cl-IPN, IPN, 2,5,6-Cl₃4-(OH)-IPN and 2,5,6-Cl₃-4-(OCH₃)-IPN. Peaks with longer retention times than that of TPN were not identified. Tentative degradation pathways were proposed on the basis of the identified degradation products. About 90% of the bacterial strains isolated from the soil to which TPN had been added degraded TPN, suggesting enrichment of the soil with TPN-degrading bacteria.Japanese International Cooperation Agency     

Determination of p-hydroxybenzoic acid esters in cosmetics by liquid chromatography with ultraviolet and fluorescence detection

A simple, precise, and accurate liquid chromatographic method with both ultraviolet (UV) and fluorescence detection is described for the determination of methyl, ethyl, propyl, and butyl p-hydroxybenzoates (PHBA-esters) in cosmetics. sec-Butyl p-hydroxybenzoate is added to the sample as an internal standard. Then the PHBA-esters are extracted with ether, the ether is evaporated to dryness, and the residue is dissolved in 60% (v/v) acetonitrile. The acetonitrile solution is passed through a Sep-Pak C18 cartridge to remove co-extracted lipids. PHBA-esters are determined by reverse-phase liquid chromatography with UV detection at 254 nm and fluorescence detection at ex 280 nm, em 305 nm. The mobile phase is acetonitrile-water (35 + 65). The method was linear over the concentration range of 0.005-0.15 mg/mL. Mean recoveries of each PHBA-ester were 98.9-102.7% (coefficients of variation less than or equal to 2.0%).     

High-fat diet enhances the accumulation of hexachlorobenzene (HCB) by pregnant rats during continuous exposure to HCB

To investigate the influence of a high-fat diet on HCB distribution and accumulation, pregnant rats in study 1 were fed a high-fat or control diet containing HCB, and, in study 2, pregnant rats were given a single HCB dose by intragastric gavage and HCB-free high-fat or control diet. In study 1, the high-fat diet group had higher HCB concentrations in fat tissues and liver than did the controls. In study 2, although the total amounts of HCB in the fat tissue and liver were greater in the high-fat diet group than in the controls, no significant differences in HCB concentration were observed between the two groups. The high-fat diet group also showed more fecal excretion of HCB. Therefore, HCB accumulation in rats fed a high-fat diet was enhanced more by continuous exposure to HCB than by administration of a single dose.     

Survival of inoculant Bradyrhizobium japonicum in an Andosol

The survival of an antibiotic-resistant mutant of a commercial inoculant Bradyrhizobium japonicum strain, A1017ks, was studied in a volcanic ash soil (Andosol) in comparison with a non-volcanic ash soil (Fluvisol) over a period of 84 days. In a non-sterile soil system, the population decline in the Andosol (15% or 1.2 log units) was larger than in the Fluvisol (6% or 0.54 log units). In both soils, however, the inoculant bradyrhizobium survived at fairly high population levels after the period of incubation [10⁶ and 10⁷ colony-forming units (CFU) g^-1 dry soil in the Andosol and Fluvisol, respectively]. In sterile control soil, viable bradyrhizobium cells could not be detected after 1 week of incubation in the Andosol, whereas in the Fluvisol population of introduced bradyrhizobium was maintained throughout the period of incubation. Overall changes in the population of indigenous bacteria and fungi were also monitored. However, no clear pattern of interaction between the inoculant Bradyrhizobium japonicum and the indigenous microbes could be identified. The antibiotic-resistant mutant maintained its resistance in the Fluvisol throughout the 3-month period of incubation, making it a useful model for conducting ecological studies in the soil.