Dissolved organic carbon concentration of a natural water body and its relationship to water color in Central Kalimantan, Indonesia

In Central Kalimantan, Indonesia, the water of lakes and rivers showed high dissolved organic carbon (DOC) concentration, 5-50mgC/l. There was a clear relationship between DOC concentration and pH. DOC also contributed to low water transparency in the studied lakes. Water colors measured by spectrophotometer showed a strong relationship with DOC concentration, indicating high applicability of water color measurement for estimation of DOC. The development of a simple but quick estimation of DOC will contribute to understanding the seasonal dynamics of DOC, which might regulate both abiotic and biotic conditions in aquatic ecosystems in this area.     

Sister-chromatid exchanges in lymphocytes of workers exposed to trichloroethylene

To detect mutagenic effects of trichloroethylene (TCE) on humans, sister-chromatid exchanges (SCEs) were analyzed in lymphocytes of 22 workers occupationally exposed to TCE and 22 matched controls. Although urinalysis in the workers revealed their obvious exposure to TCE, no increase in SCE frequencies was found in lymphocytes of the workers. SCE analysis in lymphocytes could not detect mutagenic effects by occupational exposure to TCE on humans.     

Both low and high concentrations of staurosporine induce G1 arrest through down-regulation of cyclin E and cdk2 expression

Staurosporine has been reported to cause arrest of cells in G1 phase at low concentration and in G2 phase at high concentration. This raises the question of why the effects of staurosporine on the cell cycle depend on the applied concentration. In order to verify these multiple functions of staurosporine in Meth-A cells, we used cyclin E as a landmark of G1/S transition, cyclin B as a landmark of G2/M transition and MPM2 as a hallmark of M phase. We found that staurosporine arrested cells in G1 phase at a low concentration (20 nM) and in G2/M phase at a high concentration (200 nM). However, 200 nM staurosporine increased the expression of cyclin B and cdc2 proteins, suggesting that the cells progressed through the G2/M transition, and increased the expression of MPM2 protein, indicating that the cells entered M phase. Moreover, 200 nM staurosporine increased the expression of p53 and p21 proteins and inhibited the expression of cyclin E and cdk2 proteins, suggesting that the cells were arrested in the G1 phase of the next cycle. Morphological observation showed similar results as well. These data suggest that the G2/M accumulation induced by 200 nM staurosporine does not reflect G2 arrest, but rather results from M phase arrest, followed by progression from M phase to the G1 phase of the next cycle without cytokinesis, and finally arrest of the cells in G1 phase.     

Preparation of (2S,4R)‐2,4‐thiazolidinedicarboxylic acid by separation of diastereoisomeric salts with organic amines

L ‐Cysteine was condensed with glyoxylic acid monohydrate in acetic acid at 30°C to give (4R)‐2,4‐thiazolidinedicarboxylic acid [(4R)‐TDA] as a mixture of two diastereoisomers, (2R,4R)‐ and (2S,4R)‐TDA. An attempt was made to separate (2S,4R)‐TDA from the diastereoisomeric salts of (4R)‐TDA with 1‐propylamine, 2‐methyl‐2‐propylamine, benzylamine, and (R)‐ and (S)‐1‐phenylethylamines [(R)‐ and (S)‐PEA]. The salts of (2S,4R)‐TDA were preferentially crystallized as less soluble diastereoisomeric salts. When the salt with (R)‐PEA was employed, the separation was successfully achieved to afford optically pure (2S,4R)‐TDA in a yield of 41%, based on the starting amount of the diastereoisomeric mixture of (4R)‐TDA. Chirality 11:326–329, 1999. © 1999 Wiley‐Liss, Inc.     

Essential structure of orexin 1 receptor antagonist YNT-707, part III: Role of the 14-hydroxy and the 3-methoxy groups in antagonistic activity toward the orexin 1 receptor in YNT-707 derivatives lacking the 4,5-epoxy ring

Morphinan derivatives lacking the 4,5-epoxy ring were synthesized to examine the participation of the 14-OH group, the 3-OMe group, and the aromaticity of the A-ring in the activity and selectivity for the orexin 1 receptor (OX₁R). The assay results and the conformational analyses of the 14-dehydrated and 14-H derivatives suggested that the orientations of the 6-amide side chain and the 17-benzenesulfonyl group would play important roles in the activity for OX₁R. In the 6β-derivatives, removal of the 3-OMe group and the reduction of the A-ring significantly decreased the activity toward the OX₁R, but these changes did not affect the 6α-derivatives. These results indicate that the 3-OMe group and the A-ring would be essential structural moieties for the 6β-derivatives.     

Establishment and characterization of human uterine cervical epidermoid carcinoma cell line HHUS containing HPV 59 DNA

The cell line designated HHUS was established from human uterine cervical keratinizing squamous cell carcinoma. The HHUS cell line was subcultivated more than 70 times within 3 years. The cultured cells, polygonal or spindle, with neoplastic and pleomorphic features, appeared epithelial in shape, with a pavement-like arrangement and grew in multi-layers without contact inhibition. The chromosome number was varied from 40 to 88, and the modal number was stable in diploid range. The cultured cells produced keratinizing squamous cell carcinomas by heterotransplantation into the subcutis of nude mice. The HHUS cells were characterized as producing large amounts of SCC, in vitro and possessing HPV-59 DNA genomes.     

Pheromone-gland-specific fatty-acyl reductase in the adzuki bean borer,Ostrinia scapulalis (Lepidoptera: Crambidae)

The adzuki bean borer moth, Ostrinia scapulalis, uses a mixture of (E)-11- and (Z)-11-tetradecenyl acetates as a sex pheromone. At a step in the pheromone biosynthetic pathway, fatty-acyl precursors are converted to corresponding alcohols by an enzyme, fatty-acyl reductase (FAR). Here we report the cloning of FAR-like genes expressed in the pheromone gland of female O. scapulalis, and the characterization of a single pheromone-gland-specific FAR (pgFAR) and its functional assay using an insect cell expression system. As many as thirteen FAR-like genes (FAR-I–FAR-XIII) were expressed in the pheromone gland of O. scapulalis; however, only one (FAR-XIII) was pheromone-gland-specific. The deduced amino acid sequence of FAR-XIII predicted a 462-aa protein with a conserved NAD(P)H-binding motif in the N-terminal region, showing overall identity of 34% with the pgFAR of Bombyx mori. A functional assay using Sf9 cells transfected with an expression vector containing the open reading frame of the FAR-XIII gene has proven that FAR-XIII protein has the ability to convert a natural substrate, (Z)-11-tetradecenoic acid, to a corresponding alcohol, (Z)-11-tetradecenol.     

Protective Role of Fas-FasL Signaling in Lethal Infection with Herpes Simplex Virus Type 2 in Mice

Herpes simplex virus type 2 (HSV-2) induces acute local infection followed by latent infection in the nervous system and often leads to the development of lethal encephalitis in immunocompromised hosts. The mechanisms of immune protection against lethal HSV-2 infection, however, have not been clarified. In this study, we examined the roles of Fas-Fas ligand (FasL) signaling in lethal infection with HSV-2 by using mice with mutated Fas (lpr) or FasL (gld) in C57BL/6 background. Both lpr and gld mice exhibited higher mortality than wild-type (WT) C57BL/6 mice after infection with virulent HSV-2 strain 186 and showed significantly increased viral titers in the spinal cord compared with WT mice 9 days after infection, just before the mice started to die. There were no differences in the numbers of CD4⁺ and CD8⁺ T cells infiltrated in the spinal cord or in the levels of HSV-2-specific gamma interferon produced by those cells in a comparison of lpr and WT mice 9 days after infection. Adoptive transfer studies demonstrated that CD4⁺ T cells from WT mice protected gld mice from lethal infection by HSV-2. Furthermore, CD4⁺ T cells infiltrated in the spinal cord of HSV-2-infected WT mice expressed functional FasL that induced apoptosis of Fas-expressing target cells in vitro. These results suggest that FasL-mediated cytotoxic activity of CD4⁺ T cells plays an important role in host defense against lethal infection with HSV-2.Fas-Fas ligand (FasL) signaling-induced apoptotic cell death has pleiotropic roles in T-cell-mediated host defense mechanisms. First, Fas and FasL are expressed on activated T cells and thereby limit their number by inducing suicide or fratricide. It is generally accepted that Fas-mediated activation-induced cell death plays a predominant role during chronic infection, whereas starvation-induced cell death mediated by the proapoptotic BH3-only subgroup of the Bcl-2 protein family is the main mechanism for T-cell death during termination of immune responses in acute infection (30). Fas-FasL signaling might also play a role in T-cell development, as suggested by an accumulation of T-cell receptor αβ-positive (TCR αβ⁺) CD4⁻ CD8⁻ T cells expressing B220 in lymphoid organs of mice with mutated Fas (lpr) or FasL (gld) although the origin and functions of such double-negative T cells are still a matter of debate (21). Lastly, Fas-FasL interaction can be directly involved in host defense by inducing apoptosis of infected cells to facilitate pathogen clearance (23). Therefore, the roles of Fas-FasL signaling in immune responses for host defense might vary depending on the pathogen.Herpes simplex virus type 2 (HSV-2) is an alphaherpesvirus that causes genital herpes, the most common viral sexually transmitted disease (29). After initial infection in the vaginal epithelium, HSV-2 invades local nerve termini, travels via retrograde axonal transport to neuronal cell bodies in sensory ganglia, and establishes latent infection (13). However, especially in neonates and immunocompromised hosts, HSV-2 can cause lethal central nervous system (CNS) infection, which indicates the importance of immune systems in limiting the pathogenicity of HSV-2. Immune responses against HSV-2 have been studied in various murine models using different strains of virus and routes of inoculation, with or without vaccination with an attenuated strain of HSV-2. In such vaccination models, CD4⁺ T cells producing gamma interferon (IFN-γ) predominantly conferred protection against challenge with a virulent strain of HSV-2 (11, 19), whereas various subsets of lymphocytes, including NK cells, NK T cells, and TCR γδ T cells as well as CD4⁺ T cells were reported to be involved in host defense against primary infection with virulent HSV-2 (3, 15, 24), in which IFN-γ also played an important role (9). Fas-FasL signaling was shown to be dispensable for the clearance of an attenuated strain of HSV-2, which lacks thymidine kinase and causes only transient mild vaginal pathologies but not neurologic diseases (6, 16). Similarly Fas-mediated apoptosis was not involved in the vaccination effect of the attenuated HSV-2 (11). However, the roles of Fas-FasL signaling in host defense against a virulent strain of HSV-2 have not been clarified.In this study, we examined the roles of Fas-FasL signaling in a murine model of HSV-2 infection by using a highly virulent HSV-2 strain 186 with lpr and gld mice. We found that FasL-Fas signaling plays an important role in host defense against lethal HSV-2 infection.     

Synthesis and properties of bifunctional chloroalkyl nitrosamines with an intercalating moiety

Three N-nitroso-N-(arylcarbonyloxymethyl)-3-chloropropylamines were synthesized, and their chemical and biological properties were studied. All arylcarboxylates intercalated with double-stranded DNA, and their mutagenicity and DNA cross-linking activity were affected by their ring structure. The DNA interstrand cross-link formation increased dose dependently after treatment with the acridine analog. The anthraquinone analog showed the highest bacterial mutagenicity among the three nitrosamines in Salmonella typhimurium TA100, while in Salmonella typhimurium TA92, which can detect cross-linking agents, the acridine analog showed the highest mutagenicity. This agreed with the result of a cross-linking assay. These results suggest that the three-ring aromatic moiety gives DNA-intercalating ability to cross-linkable chloropropyl nitrosamine, and the acridine analog is considered as a possible new antitumor lead compound.     

"Aqua-space", a new headspace method for isolation of natural floral aromas using humidified air as a carrier gas

A new method called "Aqua-space" was developed for the isolation of the natural fragrances of plants. Living flowers were enclosed in a space under simulated natural conditions, and humidified air was pumped into the space as a fragrance carrier. In a comparison among three isolation methods, i.e., Aqua-space, headspace, and solvent extraction, the Aqua-space method proved to be the most effective in retaining natural fragrances with abundant oxygenated components key to floral fragrances.