Focus Group Abstracts

Sleep and Biological Rhythms -     

Conformation of poly(γ‐glutamic acid) in aqueous solution

Local conformation and overall conformation of poly(γ‐DL‐glutamic acid) (PγDLGA) and poly(γ‐L‐glutamic acid) (PγLGA) in aqueous solution was studied as a function of degree of ionization ε by ¹H‐NMR, circular dichroism, and potentiometric titration. It was clarified that their local conformation is represented by random coil over an entire ε range and their overall conformation is represented by expanded random‐coil in a range of ε > ε^*, where ε^* is about 0.3, 0.35, 0.45, and 0.5 for added‐salt concentration of 0.02M, 0.05M, 0.1M, and 0.2M, respectively. In a range of ε < ε^*, however, ε dependence of their overall conformation is significantly differentiated from each other. PγDLGA tends to aggregate intramolecularly and/or intermolecularly with decreasing ε, but PγLGA still behaves as expanded random‐coil. It is speculated that spatial arrangement of adjacent carboxyl groups along the backbone chain essentially affects the overall conformation of PγGA in acidic media. © 2015 Wiley Periodicals, Inc. Biopolymers 105: 191–198, 2016.     

Three new species of Kockovaella isolated from plants collected in the Ogasawara Islands

Five strains of unknown ballistoconidiogenous yeasts, which were isolated from plant leaves collected in the Ogasawara Islands, Japan, were taxonomically studied. They represent three different species of the genus Kockovaella based on morphological, physiological and biochemical characteristics, analysis of small subunit ribosomal RNA gene sequences, and DNA-DNA reassociation experiments. Three new species, Kockovaella machilophila (1 strain), Kockovaella phaffii (3 strains) and Kockovaella schimae (1 strain) are proposed for these five strains.     

CXCR4 and CCR5 Genetic Polymorphisms in Long-Term Nonprogressive Human Immunodeficiency Virus Infection: Lack of Association with Mutations other than CCR5-Δ32

Polymorphisms in the coding sequences of CCR5 and CXCR4 were studied in a group of human immunodeficiency virus (HIV)-infected long-term nonprogressors. Two different point mutations were found in the CXCR4 coding sequence. One of these CXCR4 mutations was silent, and each was unique to two nonprogressors. The well-described 32-bp deletion within the CCR5 coding sequence (CCR5-Δ32) was found in 4 of 13 nonprogressors, and 12 different point mutations were found scattered over the CCR5 coding sequence from 8 nonprogressors. Most of the mutations created either silent or conservative changes in the predicted amino acid sequence: only one of these mutations was found in more than a single nonprogressor. All nonsilent mutations were tested in an HIV envelope-dependent fusion assay, and all functioned comparably to wild-type controls. Polymorphisms in the CXCR4 and CCR5 coding sequences other than CCR5-Δ32 do not appear to play a dominant mechanistic role in nonprogression among HIV-infected individuals.     

Temporal and spatial pattern of the biochemical activation of the endosperm during and following imbibition of tomato seeds

Electron microscopic observations of the endosperm of tomato ( Lycopersicon esculentum Mill.) seeds revealed that changes in the cell wall structures along with the vacuolation of protein bodies occurred in the micropylar portion of the endosperm prior to germination. No changes were detected at that time in the rest of the endosperm. Endo‐β‐mannanase activity was restricted to the micropylar region of the endosperm prior to germination. Cell wall digestion by this pregerminative mannanase seemed to be associated with the changes in cell wall structures occurring in the micropylar region prior to germination. The protein content in the micropylar part of the endosperm began to decrease shortly after imbibition and attained about 40% of the initial level by the time of radicle protrusion (38 h after imbibition). On the other hand, only slight changes in the content were detected in the lateral endosperm during the same time; the protein content in the lateral endosperm decreased only after germination started. In conformity with the results on protein contents, proteolytic activity began to develop first in the micropylar portion prior to germination, and then in the lateral portion after germination. Thus, the timing of the biochemical activation of the endosperm after imbibition differed between the micropylar and the lateral region. Some qualitative differences in patterns of polypeptides synthesized in vivo were detected, as analyzed by pulse‐labeling and fluorography, between the micropylar and the lateral portions of the endosperm of seeds imbibed for 25 h. This suggests that processes of the biochemical activation of the endosperm may be qualitatively, as well as quantitatively, different depending on the regions of the endosperm.     

A report from Japan: choices of Japanese patients in the face of disagreement

Background: Patients in different countries have different attitudes toward self-determination and medical information. Little is known how much respect Japanese patients feel should be given for their wishes about medical care and for medical information, and what choices they would make in the face of disagreement.
Methods: Ambulatory patients in six clinics of internal medicine at a university hospital were surveyed using a self-administered questionnaire.
Results: A total of 307 patients participated in our survey. Of the respondents, 47% would accept recommendations made by physicians, even if such recommendations were against their wishes; 25% would try to persuade their physician to change their recommendations; and 14% would leave their physician to find a new one.
Seventy-six percent of the respondents thought that physicians should routinely ask patients if they would want to know about a diagnosis of cancer, while 5% disagreed; 59% responded that physicians should inform them of the actual diagnosis, even against the request of their family not to do so, while 24% would want their physician to abide by their family's request and 14% could not decide. One-third of the respondents who initially said they would want to know the truth would yield to the desires of the family in a case of disagreement.
Interpretations: In the face of disagreement regarding medical care and disclosure, Japanese patients tend to respond in a diverse and unpredictable manner. Medical professionals should thus be prudent and ask their patients explicitly what they want regarding medical care and information.     

Ramet production byMallotus japonicus, a common pioneer tree in temperate Japan

To clarify the characteristics of clonal growth ofMallotus japonicus, we excavated all roots of this species in a plot and ascertained the connections between shoots. All shoots examined were ramets that originated from roots. Young ramets grew in shady sites as well as sunnier sites, indicating that ramet production was not dependent on local light conditions.     

Endo-β-mannanases in the endosperm of germinated tomato seeds

Three forms of galactomannan-hydrolyzing enzymes (dyed galactomannan as substrate) were partially purified from germinated tomato [ Lycopersicon esculentum (L.) Mill.] seed. Two of the enzymes were of the same molecular mass, 38 kDa, as judged by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), but the points of elution from a CM-Toyopearl column by a pH-gradient were different between the two (pH 5.15 and 5.45. respectively). The molecular mass of the third form was slightly less (37.5 kDa) than that of the other two. These 3 enzymes showed no α-galactosidase (EC 3.2.1.22) or β-mannosidase (EC 3.2.1.25) activity. Thin-layer chromatography (TLC) revealed that the products of the reaction were oligosaccharides and that free galactose and mannose were not released. These results indicate that the 3 galactomannan-hydrolyzing enzymes are endo-β-mannanases (EC 3.2.1.78). Polyclonal antibodies raised against the 37.5-kDa polypeptide cross-reacted with the two 38-kDa polypeptides, indicating that the 3 endo-β-mannanases are immunologically homologous. Activity staining and immunoblotting of native PAGE of endosperm extracts revealed that only two (38-kDa. elution point pH 5.15 and 37.5-kDa proteins) of the 3 forms were major endo-β-mannanases present in the endosperm of germinated tomato seeds.     

Neonatal lethality of mouse A/J-7SM consomic strain is caused by an insertion mutation in the Dchs1 gene

Mammalian Genome - Homosomic mice of the A/J-7SM consomic mouse strain that introduced the entire chromosome 7 (Chr 7) of SM/J into the A/J strain exhibited neonatal lethality. We tentatively...     

The Activity of α-Amylase in the Shoot and its Relation to Gibberellin-induced Elongation

The activity of α-analyses in various plant organs was examined and the relation- ship between the enzyme activity and the leaf sheath elongation of dwarf mutants of maize was investigated. It has been shown that α-amylase exists in various plant organs. Especially high activity was detected in the bean hypocotyl. The regional activity of a-amylase in the epicotyl of the pea and the hypocotyl of the morning glory was examined. Higher activity was observed in the regions closer to the cotyledons. In the first leaf sheath of d₅ mutants of maize, GA₃-treatment resulted in the promotion of α-amylase activity, and there was a parallelism between GA₃-induced elongation and α-amylase activity. Removal of the endosperm from seedlings did not influence the GA₃-indnced elongation of the leaf sheath or the promotion of α-amylase activity. From these results it is concluded that at least some of the α-amylase is actually formed in the leaf sheath, and that there exists a distinct parallelism between the GA₃-induced promotion of enzyme activity and leaf sheath elongation.