Determination of the period for establishment of a liver network echogenic pattern in Schistosoma japonicum infection

Schistosomiasis is caused by infection with Schistosoma haematobium, S. mansoni, S. japonicum, or S. mekongi. S. japonicum infection results in liver cirrhosis at the final stage. A "network" (NW) echogenic pattern on hepatic ultrasonography appears to be specific to S. japonicum infection. The principal aim of the present study was to determine the exact year(s) or even month(s) required for the establishment of the liver NW echogenic pattern from the initial infection in young patients with schistosomiasis japonica since there are few data on this important point. We conducted yearly ultrasonographic, serologic, coprologic, and physical examinations of schistosomiasis patients in the Philippines from 1996 up to the present. During that period, the total number of patients examined was approximately 2,000, among whom we selected 2 patients for determination of the duration required for NW establishment, when they were 10 years old. Although the exact time of initial exposure to schistosomes cannot be determined, the duration for the establishment of NW was definitively confirmed in patient no. 1 to be between 19-24 months based on the results of serologic and coprologic examinations. For patient no. 2, the circumstantial evidence suggested that the establishment of a NW might require 5 to 6 years at maximum. To the best of our knowledge, this is the first evidence-based report on the determination of the period required for the establishment of a liver NW echogenic pattern in S. japonicum infection in the Philippines.     

Fecal microbial diversity in a strict vegetarian as determined by molecular analysis and cultivation

Fecal microbial diversity in a strictly vegetarian woman was determined by the 16S rDNA library method, terminal restriction fragment length polymorphism (T-RFLP) analysis and a culture-based method. The 16S rDNA library was generated from extracted fecal DNA, using bacteria-specific primers. Randomly selected clones were partially sequenced. T-RFLP analysis was performed using amplified 16S rDNA. The lengths of T-RF were analyzed after digestion by HhaI and MspI. The cultivated bacterial isolates were used for partial sequencing of 16S rDNA. Among 183 clones obtained, approximately 29% of the clones belonged to 13 known species. About 71% of the remaining clones were novel "phylotypes" (at least 98% similarity of clone sequence). A total of 55 species or phylotypes were identified among the 16S rDNA library, while the cultivated isolates included 22 species or phylotypes. In addition, many new phylotypes were detected from the 16S rDNA library. The 16S rDNA library and isolates commonly included the Bacteroides group, Bifidobacterium group, and Clostridium rRNA clusters IV, XIVa, XVI and XVIII. T-RFLP analysis revealed the major composition of the vegetarian gut microbiota were Clostridium rRNA subcluster XIVa and Clostridium rRNA cluster XVIII. The dominant feature of this strictly vegetarian gut microbiota was the detection of many Clostridium rRNA subcluster XIVa and C. ramosum (Clostridium rRNA cluster XVIII).     

Urinary and serum titanium: assessment as an indicator of exposure to ammonium citratoperoxotitanate (IV) and its influence on renal function

Ammonium citratoperoxotitanate IV (TAS-FINE) is a water-soluble titanium complex used to synthesize a photocatalytic titanium(IV) oxide film. This study was aimed to investigate the LD50, dose-response, time-course response, and renal toxicity of TAS-FINE using an animal model. Serum titanium (S-Ti) and its 24-h urinary excretion (U-Ti) were determined by inductively coupled plasma-argon emission spectrometry (ICPAES) after a single oral TAS-FINE administration to male Wistar rats. The LD50 of TAS-FINE was 7.97 g/kg body weight in 24 h, and its half-life was 3.78+/-1.28 d for S-Ti and 2.19+/-0.09 d for U-Ti. Although TAS-FINE was not easily absorbed in the gastrointestinal tract, it was distributed into the bloodstream in a dose-dependent manner. Within 24 h, 0.189% of administrated Ti was excreted via urine. It was speculated that TAS-FINE formed conjugates with serum constituents that resulted in nephrotoxicity resulting from an allergic reaction. The observed indices in this study were revealed to be good indicators for TAS-FINE exposure. The analytical method and animal model described in this study will help to further elucidate details about human exposure to TAS-FINE, which in recent times has become an occupational and environmental toxicant of concern.     

Copper and zinc fractions affecting microorganisms in long-term sludge-amended soils

The influences of Zn and Cu on soil enzyme activities (acid phosphatase, alkaline phosphatase, arylsulfatase, cellulase, dehydrogenase, protease (z-FLase), urease, beta-D-glucosidase and beta-D-fructofuranosidase (invertase)) and microbial biomass carbon were investigated in agricultural soils amended with municipal sewage sludge or compost since 1978. The trace metals in the soils were fractionated using a sequential extraction method. Long-term application of the sewage sludge and composts caused accumulations of Cu and Zn in the soils, ranging from 140 to 144 and from 216 to 292 mg kg(-1), respectively. The percentage of Cu was highest in the NaOH- and HNO3-extractable fractions (44-51% and 38-46%, respectively), while the percentage of Zn was highest in the HNO3- and EDTA-extractable fractions (65-83% and 11-32%, respectively). Although the percentage of the bioavailable fractions (sum of KNO3 + H2O-, NaOH-, and EDTA-extractable amounts) of Cu (53-64%) was higher than that of Zn (15-37%), the percentage of the most labile fractions (KNO3 + H2O) of Zn (2.1-5.9%) was larger than that of Cu (1.1-2.4%). The size of the microbial biomass carbon increased with the application of sewage sludge or compost. For some enzymes, however, the ratio of the enzyme activity to microbial biomass was lower in the soils amended with sewage sludge or compost than that in the control soil. The soil enzyme activities were more adversely affected by Zn than by Cu. From a multiple regression analysis, it was found that dehydrogenase, urease, and beta-D-glucosidase activities were reduced by the KNO3 + H2O-extractable fraction of Zn in the soils. These microbial activities seem to be sensitive to Zn stress, indicating the possibility that they might be useful bioindicators for evaluation of the toxic effects of Zn on microorganisms in the soils.     

Adaptive response of Schizosaccharomyces pombe to hydrogen peroxide

Abstract Schizosaccharomyces pombe becomes resistant to killing by high concentration of hydrogen peroxide and other severe stresses including oxidants, high temperature and high concentration of ethanol when pretreated with nonlethal levels of hydrogen peroxide. In the presence of the protein synthesis inhibitor, cycloheximide, during hydrogen peroxide pretreatment, the cell obtained partial resistance to a higher level of hydrogen peroxide. The partial resistance to hydrogen peroxide in the presence of cycloheximide was acquired within 30 min of pretreatment but complete resistance obtained with de novo protein synthesis was not attained before 45 min of pretreatment. During adaptation to hydrogen peroxide, at least 15 polypeptides are induced, as analyzed by two-dimensional gel electrophoresis. Catalase activity is induced eight-fold by treatment with a nonlethal level of hydrogen peroxide.     

Type V collagen in splenic reticular fibers of the macaque monkey

The distribution of type I, III and V collagens in the monkey spleen was examined by indirect immunofluorescent microscopy and immunoelectron microscopy, and compared with that of reticular fibers revealed by a silver impregnation method. Type I collagen was localized on reticular fibers in the white pulps and on coarse reticular fibers in the splenic cords. Type III collagen was localized on the reticular fibers in the white pulps, and on the coarse reticular fibers and a limited number of fine reticular fibers, in the splenic cords. The anti-type V collagen antibody reacted with annular reticular fibers around the splenic sinuses, as well as with the reticular fibers in the white pulps and with the coarse and fine reticular fibers in the splenic cords. Thus, the distribution pattern of fibers that reacted with the anti-type V collagen antibody was very similar to that of the reticular fibers revealed by the silver impregnation method. Electron-microscopically, the fine reticular fibers in the splenic cords were composed of collagen fibrils, 30-50 nm in diameter, and amorphous substances. They were covered by reticular cell processes. By immunoperoxidase labeling with the anti-type V collagen antibody, electron-dense reaction products were found over the collagen fibrils with a banding pattern. These results indicate that type V collagen is an indispensable component of the reticular fibers.     

Control of angiotensinogen production by H4 rat hepatoma cells in serum-free culture

Summary A serum-free, hormone and attachment factor supplemented culture for rat H4 hepatoma cells was established. In the defined medium (Dulbecco's Modified Eagle's +Ham's F12+insulin, transferrin, fibronectin liver cell growth factor, and sodium selenite), H4 cells grew equally well as in 10% fetal bovine serum supplemented medium. H4 cells in either defined or serum-containing culture conditions produce transferrin but not albumin or alpha-fetoprotein. In this paper we have studied the effect of various hormones and pressor peptides on the production of angiotensinogen by H4 cells cultured in defined conditions. Only glucocorticoid hormone had a significant effect on the production of angiotensinogen, whereas other hormones previously reported to exert their effect on angiotensinogen production had little or no effect. This work was supported by grant P01 CA37589 from the National Institutes of Health, Bethesda, MD.