Physiological Studies on Thiobacilli

The electrophoretically pure preparation of cytochrome c from Thiobacillus thiooxidans was obtained. The absorption spectrum exhibited maxima at 415, 521 and 550 mμ in reduced form. The various properties of the cytochrome were very close to these of mammalian cytochrome c, i. e., absorption spectrum, electrophoretic pattern, isoelectric point and E₀′.

Electrophoretically homogenous preparation of NADPH-cytochrome c oxidoreductase was isolated from the soluble fraction of Thiobacillus thiooxidans. The purification of the enzyme was carried out using the fractionation with ammonium sulfate, the treatment with Amberlite IRC-50 and the disk electrophoresis.     

Validity of ultrasound muscle thickness measurements for predicting leg skeletal muscle mass in healthy Japanese middle-aged and older individuals

Background

The skeletal muscle mass of the lower limb plays a role in its mobility during daily life. From the perspective of physical resources, leg muscle mass dominantly decreases after the end of the fifth decade. Therefore, an accurate estimate of the muscle mass is important for the middle-aged and older population. The present study aimed to clarify the validity of ultrasound muscle thickness (MT) measurements for predicting leg skeletal muscle mass (SM) in the healthy Japanese middle-aged and older population.

Findings

MTs at four sites of the lower limb and the bone-free lean tissue mass (LTM) of the right leg were determined using brightness-mode ultrasonography and dual-energy X-ray absorptiometry (DXA), respectively, in 44 women and 33 men, 52- to 78-years old. LTM was used as a representative variable of leg skeletal muscle mass. In the model-development group (30 women and 22 men), regression analysis produced an equation with R² and standard error of the estimate (SEE) of 0.958 and 0.3 kg, respectively: LTM (kg) = 0.01464 × (MT_SUM×L) (cm²) - 2.767, where MT_SUM is the sum of the product of MTs at four sites, and L is length of segment where MT is determined. The estimated LTM (7.0 ± 1.7 kg) did not significantly differ from the measured LTM (7.0 ± 1.7 kg), without a significant systematic error on a Bland-Altman plot. The application of this equation for the cross-validation group (14 women and 11 men) did not yield a significant difference between the measured (7.2 ± 1.6 kg) or estimated (7.2 ± 1.6 kg) LTM and systematic error.

Conclusion

The developed prediction equation may be useful for estimating the lean tissue mass of the lower extremity for the healthy Japanese middle-aged and older population.     

Establishment and characterization of a novel ovarian clear cell carcinoma cell line,TU-OC-2, with loss of ARID1A expression

A new cell line of human ovarian clear cell carcinoma (CCC), TU-OC-2, was established and characterized. The cells were polygonal in shape, grew in monolayers without contact inhibition and were arranged in islands like pieces of a jigsaw puzzle. The chromosome numbers ranged from 41 to 96. A low rate of proliferation was observed and the doubling time was 37.5 h. The IC₅₀ values of cisplatin, 7-ethyl-10-hydroxycamptothecin (SN38), which is an active metabolite of camptothecin, and paclitaxel were 7.7 μM, 17.7 nM and 301 nM, respectively. The drug sensitivity assay indicated that TU-OC-2 was sensitive to SN38, but resistant to cisplatin and paclitaxel. Mutational analysis revealed that TU-OC-2 cells have no mutations of PIK3CA in exons 9 and 20 and of TP53 in exons 4–9. We observed the loss of ARID1A protein expression in TU-OC-2 cells by western blot analysis and in the original tumor tissue by immunohistochemistry. This cell line may be useful for studying the chemoresistant mechanisms of CCC and exploring novel therapeutic targets such as the ARID1A-related signaling pathway.     

Differences in flowering phenology,architecture, sexual expression and resource allocation between a heavily haired and a lightly haired nettle population: relationships with sika deer

Plant Ecology - Japanese stinging nettles, Urtica thunbergiana, in Nara Park (660 ha), central Japan, where several hundred sika deer Cervus nippon have been protected for...     

Evaluation of the allergenicity of ω5-gliadin-deficient Hokushin wheat (1BS-18) in a wheat allergy rat model

We previously developed Hokushin wheat line as a hypoallergenic wheat lacking ω5-gliadin (1BS-18), a major allergen for wheat-dependent exercise-induced anaphylaxis. However, the allergenicity of 1BS-18 has not been understood completely. In this study, we evaluated the allergenicity of 1BS-18 such as anaphylactic elicitation ability and sensitization ability using rats sensitized with ω5-gliadin or glutens prepared from Hokushin (Hokushin gluten) or 1BS-18 (1BS-18 gluten). Rats were sensitized by intraperitoneal administration of ω5-gliadin, Hokushin gluten or 1BS-18 gluten. Immunoglobulin E-mediated systemic anaphylaxis was evaluated by measuring changes in rectal temperature for 30 min after intravenous challenge with ω5-gliadin or the test glutens in unsensitized rats or rats sensitized with ω5-gliadin or the test glutens. In ω5-gliadin-sensitized rats, intravenous challenge with ω5-gliadin or Hokushin gluten significantly decreased the rectal temperature at 30 min after challenge while challenge with 1BS-18 gluten did not reduce the rectal temperature. Furthermore, intravenous challenge with ω5-gliadin significantly decreased the rectal temperature in rats sensitized with Hokushin gluten or 1BS-18 gluten. However, the reduced degree observed in 1BS-18 gluten-sensitized rats was smaller than that in Hokushin gluten-sensitized rats. In conclusion, 1BS-18 elicited no allergic reaction in ω5-gliadin-sensitized rats and had less sensitization ability for ω5-gliadin than that of Hokushin wheat.     

Epithelial-vascular cross talk mediated by VEGF-A and HGF signaling directs primary septae formation during distal lung morphogenesis

There is increasing evidence that epithelial-vascular interactions are essential for tissue patterning. Here we identified components of the molecular cross talk between respiratory epithelial cells and pulmonary capillaries necessary for the formation of the gas exchange surface of the lung. Selective inactivation of the Vegf-A gene in respiratory epithelium results in an almost complete absence of pulmonary capillaries, demonstrating the dependence of pulmonary capillary development on epithelium-derived Vegf-A. Deficient capillary formation in Vegf-A deficient lungs is associated with a defect in primary septae formation, a morphogenetic process critical for distal lung morphogenesis, coupled with suppression of epithelial cell proliferation and decreased hepatocyte growth factor (Hgf) expression. Lung endothelial cells express Hgf, and selective deletion of the Hgf receptor gene in respiratory epithelium phenocopies the malformation of septae, confirming the requirement for epithelial Hgf signaling in normal septae formation and suggesting that Hgf serves as an endothelium-derived factor that signals to the epithelium. Our findings support a mechanism for primary septae formation dependent on reciprocal interactions between respiratory epithelium and the underlying vasculature, establishing the dependence of pulmonary capillary development on epithelium-derived Vegf-A, and identify Hgf as a putative endothelium-derived factor that mediates the reciprocal signaling from the vasculature to the respiratory epithelium.     

The sex-determining locus in the tiger pufferfish, Takifugu rubripes

The tiger pufferfish (fugu), Takifugu rubripes, is a model fish that has had its genome entirely sequenced. By performing genomewide linkage analyses, we show that the sex of fugu is determined by a single chromosomal region on linkage group 19 in an XX-XY system.     

Synergism of accessory factors in functional expression of mammalian odorant receptors

The discovery of odorant receptors led to endeavors in matching them with their cognate ligands. Although it has been challenging to functionally express odorant receptors in heterologous cells, previous studies have linked efficient odorant receptor expression with N-terminal modifications and accessory proteins, including the receptor-transporting proteins (RTPs) and Ric8b. Here we have shown that a shorter form of RTP1, RTP1S, supports robust cell-surface and functional expression of representative odorant receptors. Using a combination of accessory proteins, including RTP1S, Ric8b, and G(alphaolf), a diverse set of untagged odorant receptors were successfully expressed heterologously due to the synergistic effects among the various accessory proteins. Furthermore, the addition of an N-terminal rhodopsin tag to the odorant receptors, along with the same set of accessory proteins, exhibits an additional level of synergism, inducing enhanced odorant receptor responses to odorants and thus defining a more efficient heterologous expression system. We then showed that the presence or absence of different N-terminal tags has little effect on the ligand specificity of odorant receptors, although the amount of receptor expressed can play a role in the ligand response profile. The accuracy of the odorant receptor heterologous expression system involving tagged odorant receptors and various accessory proteins promises success in high throughput de-orphaning of mammalian odorant receptors.