Structure-activity and structure-metabolism relationships of HIV protease inhibitors containing the 3-hydroxy-2-methylbenzoyl-allophenylnorstatine structure

A series of peptidomimetic human immunodeficiency virus (HIV) protease inhibitors containing substituted all-phenylnorstatine [APNS: (2S,3S)-3-amino-2-hydroxy-4-phenylbutyric acid] were designed and synthesized. From the structure-metabolism relationship of this type of HIV protease inhibitors, the compounds having para substitution of the phenyl ring of Apns and/or 2,6-disubstitution of the P2' benzylamine were found to be able to avoid the P2 phenol glucuronidation that occurs with SM-319777 (formerly named JE-2147, KNI-764); one of the main metabolic pathways of SM-319777. These new analogues, such as SM-322377, had more desirable pharmacokinetic profiles and more potent antiviral activity against not only wild type HIV-1 but also the multi-drug-resistant HIV-1 than SM-319777.     

Label-retaining cells in the rat submandibular gland.

To identify stem cells in salivary glands, label-retaining cells (LRCs) were established in rat submandibular glands. Developing and regenerating glands were labeled with bromodeoxyuridine (BrdU). To cause gland regeneration, the glands were injured by duct obstruction. BrdU LRCs were observed in all the parenchymal structures except for the acinus of the glands labeled during regeneration. Among these LRCs, a few, but not many, expressed neither keratin18 (K18; an acinar/duct cell marker) nor alpha-smooth muscle actin (alphaSMA; a myoepithelial cell marker), and thus were putative stem cells. These (K18 and alphaSMA)(neg) LRCs were invariably observed in the intercalated duct and the excretory duct. In the intercalated duct, they were at the proximal end bordering the acinus (the neck of the intercalated duct). Next, to test the above identification, gland extirpation experiments were performed. LRCs were established by labeling developing glands with iododeoxyuridine (IdU) in place of BrdU. Removal of one submandibular gland forced the IdU-LRCs in the remaining gland to divide. They were labeled with chlorodeoxyuridine (CldU). The (K18 and alphaSMA)(neg) LRCs in the neck of the intercalated duct and in the excretory duct did not change in number or in IdU label. The CldU label appeared in these cells and then disappeared. These results indicate that the (K18 and alphaSMA)(neg) LRCs have divided asymmetrically and are thus considered salivary gland stem cells.     

Partial purification of a morphological transforming factor from pig brain.

A protein that changes one type of embryonic rat brain cell in culture from a primitive morphology to one resembling mature glial cell has been purified 400-fold from pig brain. The procedure includes differential centrifugation, ethanol treatment, trypsin digestion and column chromatography with Sephadex G-200 and Sepharose 4B. Although not completely homogeneous, the protein is biologically active at a concentration of 1-10(-8) M. It has a molecular weight of 350 000 and is heat labile. It is inactivated by the extremes of pH and by 8 M urea. The isoionic point is lower than neutrality. The activity is resistant to DNAase, RNAase, periodate and trypsin, but is susceptible to pronase digestion.     

Permeability increase in black lipid membrane induced by compound 4880

When compound $\text{48}\text{80}$, a potent histamine liberator, was added in the aqueous phase facing the black lipid membrane, the conductivity of the membrane was remarkably increased. Although valinomycin displayed a distinct selectivity for K⁺ movement, such selection for ionic permeability was not observed in the case of compound $\text{48}\text{80}$.     

ORIGIN OF APOMICTIC RED ALGAE: OUTCROSSING STUDIES OF DIFFERENT STRAINS IN CALOGLOSSA MONOSTICHA (CERAMIALES,RHODOPHYTA)1

Various red algae lack sexual reproduction and propagate by spore recycling, but it is still unknown how apomixis originates. In previous crossing experiments, we obtained an unusual hybrid of Caloglossa monosticha M. Kamiya through the outcrossing between a male from Australia and a female from Indonesia. This hybrid was morphologically identical to a normal tetrasporophyte, but its tetraspores grew into tetrasporophytes and repeated tetraspore recycling. During 5 years of culture, no sexual reproductive structures have formed on the tetrasporelings from this hybrid or its progenies. Further hybridization experiments revealed that all the five female strains from Indonesia successfully crossed with the male strain from the East Alligator River, Australia, and most of the F₁ sporophytes demonstrated tetraspore recycling, though the germination rates of these tetraspores were quite low. The ploidy level of the hybrid tetrasporophyte was similar to the normal tetrasporophyte, rather than the parental gametophyte, based on the comparison of relative DNA contents of their nuclei. Single strand conformation polymorphism (SSCP) and sequence analyses of the internal transcribed spacer 1 (ITS1) region indicated that the alleles from both parents were present in all the hybrid tetrasporophytes examined. These results suggest that this hybrid does not carry out meiosis during sporogenesis, and heterozygous diploid sporophytes arose from tetraspores. Therefore, we believe that obligate apomixis was generated through outcrossing between genetically different entities of C. monosticha.     

Design and synthesis of regioisomerically pure unsymmetrical xanthene derivatives for staining live cells and their photochemical properties

We have demonstrated the synthesis of regioisomerically pure unsymmetrical xanthene derivatives consisting of three units which can be independently modified to control their physical properties. The photochemical properties of the synthetic unsymmetrical xanthene derivatives were investigated in solution by UV–vis absorption and fluorescence measurements, and their cell imaging properties were examined by confocal laser-scanning microscopy.     

Basic study on radon effects and thermal effects on humans in radon therapy

Because most of the diseases to which radon (222Rn) therapy is applied are related to activated oxygen, in this study the effect of the radioactivity of radon and the thermal effect were compared under a room or a hot spring condition with the same chemical component using as the parameters the activity of superoxide dismutase (SOD), which is an oxidation inhibitor, and lipid peroxide and low density lipoprotein (LDL)-cholesterol, which are closely involved in arteriosclerosis. Results show that the SOD activity was significantly increased, and the lipid peroxide and LDL-cholesterol levels were significantly decreased on days 6 and 7 of study. The results were about 2-fold larger in the radon group than in the thermo group. This suggests that the anti-oxidation function was more enhanced by radon therapy than by thermo therapy, and suggests that radon therapy may help to prevent the causes of life style-related diseases such as arteriosclerosis. These findings are important in understanding the mechanism of diseases in which radon therapy is used as treatment, and most of which are called activated oxygen-related diseases.     

Speciation and biogeography of the<Emphasis Type="Italic"> Caloglossa leprieurii</Emphasis> complex (Delesseriaceae,Rhodophyta)

Studies on the morphology, reproductive compatibility, life cycle and molecular phylogeny of the euryhaline red alga Caloglossa provide insights into the speciation events and biogeographic patterns. The C. leprieurii complex is separated into three morphotypes based on the number of cell rows at nodes and the blade width. The three morphotypes are reproductively incompatible with each other, and furthermore many mating groups are recognized within the morphotypes. Incomplete reproductive isolation is occasionally seen between geographically distant mating groups, whereas no sexual compatibility occurs between sympatrically or parapatrically distributed mating groups. In the molecular phylogenetic analyses, the C. leprieurii complex is resolved as two clusters that phenotypically correspond to the single and multiple cell row types, respectively. The strains belonging to the same mating group are closely related to each other, without exception, while the mating groups showing incomplete reproductive reactions do not always make a clade. The genetic distance is generally not correlative to the geographic distance, and this is also suggested by the morphological data and crossability. These results indicate that allopatric speciation has frequently occurred in this species complex, although there is some evidence of long-distance dispersal.M. Kamiya is the recipient of the Botanical Society Award for Young Scientist, 2002.     

Non‐monophyly of Bostrychia simpliciuscula (Ceramiales,Rhodophyta): Multiple species with very similar morphologies,a revised taxonomy of cryptic species

The discovery of a plethora of cryptic species in many algal groups has led to speculation as to the causes of this observation and has affected taxonomy, with reluctance to give names to species that look identical. While this is defensible for monophyletic cryptic species complexes, both our understanding of similar morphologies (crypsis) and nomenclature is challenged when we encounter non‐monophyletic ‘cryptic’ species. Bostrychia simpliciuscula is a wide‐ranging species in which multiple cryptic species are known. Our increased sampling shows that this species consists of four lineages that do not form a clade, but lineages are sister to species with different morphologies. Careful morphological examination shows that characters, especially branched monosiphonous laterals and rhizoid morphology in haptera, are able to distinguish these four lineages into two groups, that are still not monophyletic. The similar morphologies in these lineages could be due to convergence, but not developmental constraints or lack of time to diverge morphologically; or possibly maintenance of a generalized body plan. These lineages appear to have specific biogeographic patterns and these will be used to propose a new taxonomy. B. simpliciuscula is now confined to the tropics. Another of these lineages matches a previously described species, B. tenuissima, that was synonymized with B. simpliciuscula and is from cold temperate Australasia, and is resurrected. Another lineage is found in Japan in which a previous name is also available, B. hamana‐tokidae; the last lineage is found in central New South Wales, morphologically it resembles B. tenuissima, with which it overlaps in distribution around Sydney, and is named as a new species, B. kingii sp. nov.