Crystals from cocoons of Malacosoma neustria testacea

The crystalline material covering the cocoon of Malacosoma neustria testacea (Lasiocampidae, Lepidoptera) was analyzed physically and chemically. The mean component was identified as calcium oxalate monohydrate, and the crystals were found to be whewellite in form.     

Extension of von Bertalanffy growth model incorporating growth patterns of soft and hard tissues in bivalve molluscs

ABSTRACT:   A new practical growth model through the partial reconstruction for the von Bertalanffy function (VBF) has been proposed. In numerous studies on various species, VBF has been recognized as an appropriate function to describe growth. Here the difference in growth dynamics between soft and hard tissues is considered using VBF. A differential equation in which the growth rates of these two tissue types are described, gives a four parameter model. This advanced model showed characteristics such as: (i) S-shape curve similar to the Gompertz model; (ii) unfixed point of inflection; and (iii) definition as an implicit function. The characteristic indicated in (iii) makes it impossible to apply the method of least squares to data analysis. Therefore, a solution was introduced combining Lagrange's method of indeterminate coefficients and the Newton method. Data analysis for verifying the performance of the advanced model was conducted on published data on growth of the bivalve Spisula sachalinensis . As a result of the comparison among the existing growth models, the advanced model produced the minimum value of Akaike information criterion (AIC).     

Contribution of the type II secretion system in systemic infectivity of <Emphasis Type="Italic">Ralstonia </Emphasis><Emphasis Type="Italic">solanacearum</Emphasis> through xylem vessels

Ralstonia solanacearum strain OE1-1 (OE1-1) systemically invades tobacco plants and causes bacterial wilt. A type II secretion system (T2SS)-deficient mutant of OE1-1, derived from EZ::TN<KAN-2>transposon-insertion, retained the ability of the parent strain to produce exopolysaccharide in vitro and grow in intercellular spaces immediately after invasion of host plants, but lost the ability to systemically infect the host. With transmission electron microscopy, the mutant was not observed in xylem vessels. These findings suggest that the T2SS contributes to systemic infection by enabling the bacteria to invade xylem vessels.     

Adsorption of OP<Subscript>1</Subscript>-related bacteriophages requires the gene encoding a TonB-dependent receptor-like protein in <Emphasis Type="Italic">Xanthomonas</Emphasis><Emphasis Type="Italic">oryzae</Emphasis> pv. <Emphasis Type="Italic">oryzae</Emphasis>

Xanthomonas oryzae pv. oryzae strain T7174R is lysed by bacteriophage OP_1h and OP_1h2. Three mutants tolerant to both OP_1h and OP_1h2 were isolated by transposon mutagenesis. The mutants had an insertion of the transposon in XOO1687, which is predicted to encode a TonB-dependent receptor gene. Plasmid pHMIroNB that contained XOO1687 of T7174R was constructed, and the mutant was transformed with the plasmid. The transformant recovered sensitivity to OP_1h and OP_1h2. Electron microscopic analysis demonstrated that OP_1h and OP_1h2 can adsorb to the wild type and the transformant, but they could not adsorb to the phage-tolerant mutant. These results suggest that the TonB-dependent receptor gene relates to adsorption and infection of T7174R by OP_1h2 and OP_1h. Y. Inoue and S. Tsuge have contributed equally to this work.     

Pulmonary vascular proliferation and lungworm (Stenurus ovatus) in a bottlenose dolphin (Tursiops turncatus)

A female adult bottlenose dolphin suddenly died at 17 days after the capture. Macroscopically, severe pulmonary congestive edema was found. Histopathology revealed many lungworms in the bronchioli and the worms were identified as Stenurus ovatus. Variously sized vessels proliferated around the lesioned bronchioli. Based on these findings, chronic bronchopneumonia due to the lungworm was diagnosed and vascular proliferation was similar to angiomatosis recently reported in Atlantic bottlenose dolphin.     

Chemical-induced lung tumor in Tg-rasH2 mice: a novel mouse tumor model to assess immune checkpoint inhibitors combined with a chemotherapy drug

In subcutaneous tumor models, changes in the tumor microenvironment can lead to differences in therapeutic treatment responses between the subcutaneous and parent tumors. Accordingly, we generated a lung carcinogenesis model that combines genetically modified mice (Tg-rasH2 mice) with two-stage chemical carcinogenesis as an alternative to the subcutaneous tumor model. In this model, Tg-rasH2 mice were treated with 1-ethyl-1-nitrosourea, followed by butylhydroxytoluene. Mice developed lung adenomas five weeks after treatment initiation. Subsequently, anti-mouse PD-1 antibody (α-mPD-1) or isotype control was administered intraperitoneally twice a week for 4 weeks. Tumor growth was examined by measuring the relative tumor area in serially sliced lung histopathological specimens. No statistically significant differences were observed in the relative lung tumor areas between treated and control groups. A second experiment then examined the antitumor efficacy of α-mPD-1 combined with gemcitabine in a mouse model. Mice were treated identically as in Experiment 1, except that the treated group received once-weekly intraperitoneal injections of 10 mg/kg gemcitabine. In contrast to Experiment 1, the combined treatment significantly reduced the relative tumor areas in the lungs. This result also resembles that of a phase III clinical trial (ORIENT-12), showing that patients with non-small-cell lung carcinoma benefited from combination treatment with gemcitabine and the anti-human PD-1 antibody sintilimab. Thus, this mouse model could be a feasible means to preclinically evaluate the antitumor efficacy of different immunotherapy and chemotherapy drug combinations.     

Detection of lipid peroxidation catalyzed by chelated iron and measurement of antioxidant activity in wine by a chemiluminescence analyzer.

We measured directly the reactive oxygen generated from a peroxide-free reaction system when a ferrous complex with nitrilotriacetic acid was oxidized to the ferric complex. Further, it was observed by a measurement of chemiluminescence that peroxidation of a lipid substrate added in the system is initiated by the Fe(3+)-type of reactive oxygen generated. Antioxidant activity can be estimated by contrasting the reaction rates of lipid peroxidation between the systems with and without a putative antioxidant sample. By this method, the antioxidant activity, expressed as catechin equivalent, of red wines for linoleic acid peroxidation was shown to be higher than those of rosé and white wines (189-311, 84, and 37 microM for red, rosé, and white wines, respectively) because of a higher concentration of polyphenols such as flavanol and anthocyanin in red wines. The chemiluminescence measurement would be a promising method for evaluating the antioxidant potential because of its highly specific and sensitive detection of the hydroperoxide and for monitoring in situ peroxidation reaction.     

Phylogenetic relationships among cultivated types of <Emphasis Type="Italic">Brassica rapa</Emphasis> L. em. Metzg. as revealed by AFLP analysis

The cultivated types of Brassica rapa L. em. Metzg. consist of morphologically distinct subspecies such as turnip, turnip rape, Chinese cabbage, pak choi and pot herb mustard which are classified as ssp. rapa, ssp. oleifera, ssp. pekinensis, ssp. chinensis and ssp. nipposinica (syn. ssp. japonica), respectively. We attempted to elucidate the phylogenetic relationships among the cultivated types of B. rapa. Thirty-two accessions from the Eurasian Continent were analyzed using AFLP markers with a cultivar of B. oleracea as an outgroup. In total, 455 bands were detected in the ingroup and 392 (86.6%) were polymorphic. The Neighbor-Joining tree based on the AFLP markers indicated that the accessions of B. rapa were congregated into two groups according to geographic origin. One group consisted of ssp. rapa and ssp. oleifera of Europe and Central Asia and the other included all the subspecies of East Asia. Our results suggest that cultivars from East Asia were probably derived from a primitive cultivated type, which originated in Europe or in Central Asia and migrated to East Asia. This primitive cultivated type was probably a common ancestor of ssp. rapa and ssp. oleifera. The Neighbor-Joining tree also shows that leafy vegetables in East Asia such as ssp. pekinensis, ssp. chinensis and ssp. nipposinica were differentiated several times from the distinct cultivars of ssp. oleifera in East Asia.     

Phylogenetic position of east Tibetan natural populations in Tartary buckwheat (Fagopyrum tataricum Gaert.) revealed by RAPD analyses

Phylogenetic relationships among cultivated landraces and natural populations of wild subspecies of Tartary buckwheat were investigated by constructing an NJ tree based on RAPD markers focussing on east Tibetan natural populations. Ten plants from three cultivated landraces and 29 plants from five natural populations of wild subspecies in eastern Tibet were used for RAPD analyses. The wild subspecies from eastern Tibet was classified into three types; (1) same type as cultivated landraces; (2) closely related to natural populations of northwestern Yunnan; and (3) an exceptional population, Zhuka, which was closely related to Sichuan populations. Since the type (2) is considered as the wild ancestral type of cultivated Tartary buckwheat, we conclude that eastern Tibet too may be one of the center of origin of this crop.     

Genetic relationships among cultivated types of Perilla frutescens and their weedy types in East Asia revealed by AFLP markers

AFLP markers were employed to detect genetic diversity in two cultivated Perilla frutescens (i.e. var. frutescens and var. crispa) and their weedy types and to assess their genetic relationships. Analysis of 60 Perilla accessions from China, Korea and Japan by seven AFLP primer combinations identified a total of 125 fragments, of which 80 (64%) were polymorphic at the species level. The phenotypic diversity meassured by Shannon's index of information for the cultivated type of var. frutescens, the weedy type of var. frutescens, the cultivated type of var. crispa and the weedy type of var. crispa were on average 1.07, 2.23, 1.24 and 1.75, respectively. The weedy types exhibited high within-type variation in spite of a small number of samples. In the neighbor joining tree, two major clusters were recognized: (1) cultivated type of var. frutescens, (2) weedy type of var. frutescens, and cultivated and weedy types of var. crispa. The cultivated types of var. frutescens and of var. crispa were sharply separated by AFLPs. However, there remained ambiguities in regard to the intraspecific relaltionships, due to the clustering of the weedy types which occured in each of the clusters of the cultivated types. Two cultivated types of P. frutescens and their weedy types should be taxonomically considered as a P. frutescens complex. The present AFLP data are consistent with the hypothesis that China is the original place of cultivation of var. frutescens and Korea is a secondary center of diffusion of var. frutescens.