Demethylation of methylmercury and the enhanced production of formaldehyde in mouse liver.

Methylmercury (MeHg) is gradually changed to inorganic Hg after demethylation in animal tissues, and a selective quantification of inorganic Hg in the tissues is necessary to detect the reaction. We detected inorganic Hg formation in liver and kidney of mouse as early as 24 hr after MeHg injection. As an example of biological demethylation, the cytochrome P450 (P450)-mediated N-demethylation of drugs has been well documented, and formaldehyde was detected as a reaction product.

Preventive effects of Chlorella on skeletal muscle atrophy in muscle-specific mitochondrial aldehyde dehydrogenase 2 activity-deficient mice.

Background: Oxidative stress is involved in age-related muscle atrophy, such as sarcopenia. Since Chlorella, a unicellular green alga, contains various antioxidant substances, we used a mouse model of enhanced oxidative stress to investigate whether Chlorella could prevent muscle atrophy.

Methods: Aldehyde dehydrogenase 2 (ALDH2) is an anti-oxidative enzyme that detoxifies reactive aldehydes derived from lipid peroxides such as 4-hydroxy-2-nonenal (4-HNE).

The influence of chlorella and its hot water extract supplementation on quality of life in patients with breast cancer.

A self-control, randomized, and open-label clinical trial was performed to test the effects of the unicellular green algae Chlorella and hot water extract supplementation on quality of life (QOL) in patients with breast cancer. Forty-five female patients with breast cancer who were living at home and not hospitalized were randomly assigned to 3 groups receiving vitamin mix tablet (control), Chlorella granules (test food-1), or Chlorella extract drink (test food-2) daily for one month. The Functional Assessment of Cancer Therapy-Breast (FACT-B), the Izumo scale for abdominal symptom-specific QOL, and a narrative-form questionnaire were used to determine outcomes.

Beneficial effects of Chlorella on glucose and lipid metabolism in obese rodents on a high-fat diet.

Background: Obesity-induced glucose and lipid metabolism disorders have become risk factors for lifestyle diseases. Powderized Parachlorella beijerinckii (BP) and its hot water extract (BCEx) are believed to be useful for preventing common diseases such as hypertension, arteriosclerosis, and hyperlipidemia. The present study investigated how chlorella components influence common diseases in obese mice and rats on a high-fat diet.

Chlorella suppresses methylmercury transfer to the fetus in pregnant mice.

To investigate the effects of chlorella on methylmercury (MeHg) transfer to the fetus during pregnancy, female C57BL/6N mice (aged 10 weeks) were housed for 7 to 8 weeks, from 4 weeks before mating to birth, with diets containing 0% or 10% chlorella powder (CP) and MeHg-containing drinking water (2 µg Hg/ml). The consumption volume of the MeHg-containing water was limited to 15 ml/mouse/week throughout the experiment. Distilled water and a basal diet (0% CP) was given to control mice.

Enhanced elimination of tissue methylmercury in Parachlorella beijerinckii-fed mice.

To investigate the influence of Chlorella (Parachlorella beijerinckii) on the excretion and tissue accumulation of methylmercury (MeHg), we orally administered 5 mg/kg of MeHg chloride (4 mg Hg/kg) to female C57BL/6N mice (aged 10 weeks). The mice were housed in metabolism cages to collect urine and feces for 3 weeks with diets containing 0%, 5%, or 10% P. beijerinckii powder (BP) in a basal diet (CE-2).

The influence of Parachlorella beyerinckii CK-5 on the absorption and excretion of methylmercury (MeHg) in mice.

Chlorella (Parachlorella beyerinckii CK-5), previously identified as Chlorella vulgaris CK-5, is a unicellular green algae that has for many years been used as a nutritional supplement. In order to investigate the effects of methylmercury (MeHg) detoxification by Chlorella, we examined the absorption and excretion of MeHg in mice. Female C57BL/6N mice were randomly divided into three groups of five, and were housed in metabolism cages.

Parachlorella beyerinckii accelerates lead excretion in mice.

The effect of Parachlorella beyerinckii CK-5, previously identified as Chlorella vulgaris, on gastrointestinal absorption of lead was investigated in mice. Female ICR mice aged 7 weeks were orally administered lead acetate solution at doses of 20 mg and 40 mg of lead per mouse, with or without 100 mg of P. beyerinckii powder (BP).

Direct cytopathic effects of particular hepatitis B virus genotypes in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mouse with human hepatocytes.

Background & Aims: Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes.

Methods: Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera.

Molecular epidemiology and interferon susceptibility of the natural recombinant hepatitis C virus strain RF1_2k/1b.

Background: Hepatitis C virus (HCV) genotype is an important determinant of virological response to antiviral therapies. Currently, there are no data available on the molecular epidemiology and interferon susceptibility of the natural intergenotypic recombinant RF1_2k/1b (RF1) strain.

Methods: Genotyping and RF1-PCR screening were performed on samples from 604 HCV RNA-positive individuals from 7 countries.

Early dynamics of hepatitis B virus in chimeric mice carrying human hepatocytes monoinfected or coinfected with genotype G.

Unlabelled: Of the 8 genotypes of HBV (genotypes A-H), genotype G is unique in that it has an insertion in the core gene and two stop codons in the precore region preventing the synthesis of hepatitis B e antigen. Most individuals with genotype G are coinfected with other genotypes, typically genotype A. Mice with severe combined immunodeficiency disease carrying human hepatocytes were infected with HBV particles propagated in Huh7 cells in culture.

Activation of the CKI-CDK-Rb-E2F pathway in full genome hepatitis C virus-expressing cells.

Hepatitis C virus (HCV) causes persistent infection in hepatocytes, and this infection is, in turn, strongly associated with the development of hepatocellular carcinoma. To clarify the mechanisms underlying these effects, we established a Cre/loxP conditional expression system for the precisely self-trimmed HCV genome in human liver cells. Passage of hepatocytes expressing replicable full-length HCV (HCR6-Rz) RNA caused up-regulation of anchorage-independent growth after 44 days.

Induction of hepatic injury by hepatitis C virus-specific CD8+ murine cytotoxic T lymphocytes in transgenic mice expressing the viral structural genes.

In the present study, we generated killer cells specific for hepatitis C virus (HCV) structural protein by re-stimulation of immune spleen cells from H-2(d) haplotype transgenic (Tg) mice, expressing the core, E1, E2, and NS2 genes of HCV regulated by the Cre/loxP switching system. The generated killer cells were conventional CD8(+)L(d) class-I MHC molecule-restricted cytotoxic T lymphocytes (CTLs) and specific for the HCV E1 structural protein. Because the CTLs could also kill hepatocytes from the Tg mice expressing HCV structural proteins in vitro, we attempted to transfer those CTLs intravenously into interferon regulatory factor-1 (IRF-1) negative, CD8-deficient Tg mice representing the HCV structural genes on hepatocytes to examine whether the inoculated CD8(+) CTLs can eliminate hepatocytes expressing the HCV genes in vivo.

Two low-temperature-inducible Chlorella genes for delta12 and omega-3 fatty acid desaturase (FAD): isolation of delta12 and omega-3 fad cDNA clones, expression of delta12 fad in Saccharomyces cerevisiae, and expression of omega-3 fad in Nicotiana tabacum.

In an attempt to clarify the involvement of fatty acid desaturases (FADs) in the freezing tolerance of Chlorella vulgaris IAM C-27, developed by hardening, we have isolated cDNA clones for two types of FADs from the Chlorella strain, based on the sequence information of genes for delta12 and omega-3 FADs, respectively desaturating oleic acid (18:1) to linoleic acid (18:2) and linoleic acid (18:2) to linolenic acid (18:3). The deduced amino acid sequence of the first clone, designated CvFad2, showed about 66% similarity to the microsomal delta12 FADs from several higher plants and this gene had delta12 FAD activity when expressed in Saccharomyces cerevisiae. The predicted protein encoded by a second gene, designated CvFad3, showed about 60% similarity to the microsomal and plastidial omega-3 FADs from several higher plants.

Occurrence of Cobalamin Coenzymes in the Photosynthetic Green Alga, Chlorella vulgaris.

To analyze cobalamin metabolism in photosynthetic green algae, the effects of cobalamin on growth of Chlorella vulgaris C-30 were studied and the algal cobalamin contents were assayed. Cobalamin significantly stimulated growth of the Chlorella cells, but biologically inactive cobalamin analogues did not. Chlorella grown in a cobalamin-free medium (control) contained cobalamin coenzymes, 5'-deoxyadenosylcobalamin (7.