Cancer chemotherapy and somatic cell mutation

The occurrence of a second neoplasm is one of the major obstacles in cancer chemotherapy. The elucidation of the genotoxic effects induced by anti-cancer drugs is considered to be helpful in identifying the degree of cancer risk. Numerous investigations on cancer patients after chemotherapy have demonstrated: (i) an increase in the in vivo somatic cell mutant frequency (Mf) at three genetic loci, including hypoxanthine–guanine phosphoribosyl-transferase (hprt), glycophorin A (GPA), and the T-cell receptor (TCR), and (ii) alterations in the mutational spectra of hprt mutants. However, the time required for and the degree of such changes are quite variable among patients even if they have received the same chemotherapy, suggesting the existence of underlying genetic factor(s). Accordingly, some cancer patients prior to chemotherapy as well as patients with cancer-prone syndrome have been found to show an elevated Mf. Based on the information obtained from somatic cell mutation assays, an individualized chemotherapy should be considered in order to minimize the risk of a second neoplasm.     

Apterichtus keramanus, a new snake-eel from Okinawa, southern Japan (Ophichthinae, Ophichthidae)

A new snake-eel,Apterichtus keramanus, is described on the basis of a single 276-mm TL specimen trawled from the coast of Kerama Islands, Okinawa Prefecture, Japan. The species is unique in the genus in having the posterior nostril opening entirely inside the mouth and a dark band running from the anteroventral margin of the eye to the upper lip.     

Association between light exposure at night and manic symptoms in bipolar disorder: cross-sectional analysis of the APPLE cohort

ABSTRACT

Previous studies have found that keeping the room dark at night was associated with a decrease in manic symptoms for patients with bipolar disorder (BD). However, the association between light at night of real-life conditions and manic symptoms is unclear. We investigated the association between bedroom light exposure at night and manic symptoms in BD patients. One-hundred and eighty-four outpatients with BD participated in this cross-sectional study. The average light intensity at night during sleep was evaluated using a portable photometer for seven consecutive nights. Manic symptoms were assessed using the Young Mania Rating Scale (YMRS), and scores ≥5 were treated as a “hypomanic state.” The median (interquartile range) YMRS score was 2.0 (0–5.0), and 52 (28.2%) participants were in a hypomanic state. The prevalence of a hypomanic state was significantly higher in the participants with an average light intensity at night exposure of ≥3 lux than in those with <3 lux (36.7% versus 21.9%; P = .02). In multivariable logistic regression analysis adjusted for BD type, depressive symptoms, sleep duration, and daytime physical activity, the odds ratio (OR) for a hypomanic state was significantly higher for the participants with an average light intensity at night exposure of ≥3 lux than for those with <3 lux (OR: 2.15, 95% confidence interval: 1.09–4.22, P = .02). This association remained significant at the cutoff value of YMRS score ≥6 (OR: 2.51, 95% confidence interval: 1.15–5.46; P = .02). The findings of this study indicate bedroom light exposure at night is significantly associated with manic symptoms in BD patients. Although the results of this cross-sectional investigation do not necessarily imply causality, they may serve to inform beneficial nonpharmacological intervention and personalized treatment of BD patients.     

Change of incidence of antinuclear antibodies in serum of NOD mouse with aging

Extractable nuclear antigens (ENA) were prepared from liver of C57BL/6J mouse and analyzed by SDS PAGE Western-immunoblotting techniques. Some protein components of the ENA, with molecular weights of 94 K, 65 K, 32 K, and 26 K, reacted with antinuclear antibodies in the sera of NOD mice. Incidence of antinuclear antibodies in the sera of NOD mice with aging were measured by ELISA method using the ENA as antigen. The antinuclear antibodies were not detected in young NOD mice (10 weeks old). However, the incidence increased with aging and reached 100% in the female NOD mice of 40 weeks. In the male NOD mice, the incidence of antinuclear antibodies was delayed and low in comparison with that in female.     

Detection of nuclear protein antigens to antinuclear antibodies in serum of NOD mouse

Nuclear protein antigens to the antinuclear antibodies in serum of non-obese diabetic (NOD) mice were investigated. In the serum of diabetic NOD female mice (20 weeks old), the antinuclear antibodies were detected by indirect immunofluorescence assay using frozen sections of liver of C 57 BL/6 J or NOD mice as antigen. Nuclei were separated from the liver of C 57 BL/6 J mice and solubilized. Solubilized nuclear antigens were analyzed by SDS PAGE-Western immunoblotting techniques. Nuclear protein antigens with molecular weights of 26,000, 32,000 and 65,000 showed strongly positive reactions with the antinuclear antibodies in the serum of the NOD mouse.     

The protein factor which binds to the upstream activating sequence of Saccharomyces cerevisiae ENO1 gene.

Using a gel retardation assay it was shown that the 87 bp DNA fragment (UAS87) containing the upstream activating sequence (UAS) of S. cerevisiae EN01 gene and a nuclear extract gave rise to three migration-retarded species specific to UAS87. Heat- or proteinase-treatment of the nuclear extract revealed that these species were protein-DNA complexes. The precise binding region of the protein identified by DNaseI protection analysis was found to include a CCAAACA sequence which forms a dyad-symmetrical structure. The amount of one of the three migration-retarded species significantly increased when cells were grown in medium containing a gluconeogenic carbon source. The introduction of pGCR8, a multicopy plasmid containing GCR1 gene, a regulatory gene controlling the expression of several glycolytic enzymes, showed no effect on the amount of three migration-retarded species.     

Relationship between susceptibility and immune response to staphylococcal exfoliative toxin A in mammalian species

Staphylococcal exfoliative toxin A (ETA) had a splitting effect at the granular layer of skin in humans and neonatal mice, but not in rabbits, guinea pigs, golden hamsters, or rats. Besides its splitting effect, ETA could stimulate productions of neutralizing antibody to ETA in rabbits, rats and B10D2 mice, but not in golden hamsters, guinea pigs, or ICR, HRS/J, and C57BL/10 mice. In our epidemiological investigation of human sera, the percentage of antibody to ETA in sera obtained from patients with impetigo (8%) was lower than those in sera of healthy males (23%) and females (29%). The relationship between susceptibility and immune response to ETA in these mammalians could be divided into three groups: the possession of resistant skin and high production of antibody to ETA; the possession of resistant skin and low production of antibody to ETA; the possession of sensitive skin and various titers of antibody to ETA.     

Nucleotide sequences of Saccharomycopsis fibuligera genes for extracellular beta-glucosidases as expressed in Saccharomyces cerevisiae

We isolated two genes for extracellular beta-glucosidase, BGL1 and BGL2, from the genomic library of the yeast Saccharomycopsis fibuligera. Gene products (BGLI and BGLII) were purified from the culture fluids of Saccharomyces cerevisiae transformed with BGL1 and BGL2, respectively. Molecular weights of BGLI and BGLII were estimated to be 220,000 and 200,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The two beta-glucosidases showed the same enzymatic characteristics, such as thermo-denaturation kinetics and dependencies on pH and temperature, but quite different substrate specificities: BGLI hydrolyzed cellobiose efficiently, but BGLII did not. This result is consistent with the observation that the S. cerevisiae transformant carrying BGL1 fermented cellobiose to ethanol but the transformant carrying BGL2 did not. Southern blot analysis revealed that the two beta-glucosidase genes were derived from Saccharomycopsis fibuligera and that the nucleotide sequences of the two genes are closely related. The complete nucleotide sequences of the two genes were determined. BGL1 and BGL2 encode 876- and 880-amino-acid proteins which were shown to be highly similar to each other. The putative precursors begin with hydrophobic segments that presumably act as signal sequences for secretion. Amino acid analysis of the purified proteins confirmed that BGL1 and BGL2 encode BGLI and BGLII, respectively.     

Phosphorylation in the carboxyl-terminal domain of the capsid protein of hepatitis B virus: evaluation with a monoclonal antibody.

The capsid protein of hepatitis B virus (p21c) is made of 183 amino acids coded for by the C gene. By using p21c isolated from Dane particles (hepatitis B virus) as an immunogen, a monoclonal antibody (no. 2212) which recognized an epitope dependent on the phosphorylation of p21c was raised. The binding of no. 2212 antibody to authentic p21c was completely inhibited by a synthetic undecapeptide with a sequence of RRRSQSPRRRR, representing amino acids 165 to 175 of p21c, only when the peptide was phosphorylated. Either or both of Ser-168 and Ser-170 were phosphorylated in p21c in vivo, therefore, and contributed to the manifestation of the epitope. No. 2212 antibody bound to p21c from core particles derived from Dane particles or hepatocellular carcinoma tissues (PLC/342) propagated in nude mice but did not bind to p21c from core particles expressed in Escherichia coli or yeast cells, indicating different states of phosphorylation in them. Nonphosphorylated p21c showed a higher affinity for the viral DNA than did phosphorylated p21c. Since the serum from an asymptomatic carrier, with a high titer for antibody to hepatitis B core antigen, specifically bound to phosphorylated undecapeptide (amino acids 165 to 175), the epitope would stimulate humoral antibody responses in the human host.     

Nucleotide sequences of Saccharomycopsis fibuligera genes for extracellular beta-glucosidases as expressed in Saccharomyces cerevisiae.

We isolated two genes for extracellular beta-glucosidase, BGL1 and BGL2, from the genomic library of the yeast Saccharomycopsis fibuligera. Gene products (BGLI and BGLII) were purified from the culture fluids of Saccharomyces cerevisiae transformed with BGL1 and BGL2, respectively. Molecular weights of BGLI and BGLII were estimated to be 220,000 and 200,000 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The two beta-glucosidases showed the same enzymatic characteristics, such as thermo-denaturation kinetics and dependencies on pH and temperature, but quite different substrate specificities: BGLI hydrolyzed cellobiose efficiently, but BGLII did not. This result is consistent with the observation that the S. cerevisiae transformant carrying BGL1 fermented cellobiose to ethanol but the transformant carrying BGL2 did not. Southern blot analysis revealed that the two beta-glucosidase genes were derived from Saccharomycopsis fibuligera and that the nucleotide sequences of the two genes are closely related. The complete nucleotide sequences of the two genes were determined. BGL1 and BGL2 encode 876- and 880-amino-acid proteins which were shown to be highly similar to each other. The putative precursors begin with hydrophobic segments that presumably act as signal sequences for secretion. Amino acid analysis of the purified proteins confirmed that BGL1 and BGL2 encode BGLI and BGLII, respectively.