Saccharification of cellulose by dry pyrolysis

Pyrolysis of cellulose was studied for the purpose of practical production of 1,6-anhydro-β-D-glucopyranoside (levoglucosan, LG). To minimize secondary degradation of levoglucosan, two methods were examined: (1) conductive heating by glass bottle, and (2) radiation heating from the surface by CO₂ laser beam, both under vacuum and in a nitrogen atmosphere. Glass-bottle pyrolysis under vacuum gave levoglucosan yield of 50%–55% in the optimum temperature range of 350°–410°C, where placing the cold trap in the vicinity of heated area was effective in improving the yield. In contrast, glass-bottle pyrolysis under nitrogen gave low yields of 17%–20%, probably due to slower diffusion of pyrolysis product from hot region. The CO₂ laser pyrolysis under vacuum gave the product as aerosol (white smoke), causing difficulty in recovery of the product, and the maximum yield was 5%–17%. In this case the treatment under nitrogen flow was effective for recovery of aerosol, and the maximum yield reached approximately 25%.     

Spontaneous extraskeletal osteosarcoma in the stomach of an aged f344 rat

Extraskeletal osteosarcoma is a very rare tumor in humans and animals including rats. This paper describes a case of extraskeletal osteosarcoma observed in the glandular stomach of an aged female Fischer 344 rat. Grossly, a whitish solid mass was observed at the greater curvature of the glandular stomach. Histologically, the tumor consisted of both atypical polygonal and pleomorphic spindle-shaped cells, with pleomorphic nuclei, and it contained variable amounts of osteoids and small clumps of mature bone tissue. In addition, mitotic figures were frequently observed. Neither invasion of the muscle layer or vessels in the stomach nor metastasis to distant organs was detected. There were no skeletal tumors in the body. Immunohistochemically, the tumor cells were positive for osteocalcin, osteonectin, vimentin and S-100 protein. Judging from these results, the present tumor was diagnosed as extraskeletal osteosarcoma. This is the first report of spontaneous extraskeletal osteosarcoma arising from the stomach in a rat.     

Seasonal variations in and effect of incubation water temperature on vertebral number in naturally spawning chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>

Seasonal variations and reaction norms for vertebral number (V _N) in response to incubation water temperature were estimated in adult and juvenile naturally spawning chum salmon Oncorhynchus keta. The mean V _N of adults varied according to spawning time; the early-spawning population had higher V _N values than the late-spawning population. Moreover, the mean V _N values in the early-spawning population decreased with seasonal changes, whereas V _N values in the late-spawning population remained stable. Chum salmon embryos in three full-sib families were incubated at five different temperatures until hatching, and the V _N values of the resulting juveniles were analyzed. The V _N reaction norm to incubation water temperature showed a V-shaped curve that was lowest at an intermediate temperature. The mean V _N at the same incubation temperature varied among the three families. These results suggest that V _N values in chum salmon are influenced by genetic components and incubation water temperatures. V _N may be a useful parameter for estimating the environmental conditions during ontogenesis and the genetic background by detecting population changes.     

Detection of QTLs for white-back and basal-white grains caused by high temperature during ripening period in japonica rice

There is increasing evidence that global warming affects the development of rice. High temperatures during ripening increase the ratio of undesirable chalky grains followed by deteriorating grain appearance quality. In order to detect quantitative trait loci (QTLs) controlling the occurrence of white-back and basal-white chalky grains of brown rice, QTL analysis was performed using recombinant inbred lines derived from a cross between two strains, ‘Tsukushiroman’ (sensitive to heat stress) and ‘Chikushi 52’ (tolerant of heat stress). The F₇ and F₈ lines were exposed to heat stress during the ripening period in two locations, Fukuoka and Kagoshima, in Japan. QTLs for white-back grains and basal-white grains were detected on chromosomes 1, 3, and 8, and those for basal-white grains were detected on chromosomes 2, 3, and 12. QTLs on chromosome 8 for white-back grains were shared in the plants grown in both locations. Near-isogenic lines (NILs), which harbored a segment from ‘Chikushi 52’ on chromosome 8 with the genetic background of ‘Tsukushiroman’, showed relatively lower ratios of white-back grains than ‘Tsukushiroman’. Therefore, insertion of the ‘Chikushi 52’ genomic region of the QTL on chromosome 8 can improve the quality of rice when it is grown under heat stress conditions.     

Multiple taste functions of the umami substances in muscle extracts of yellowtail and bastard halibut

Boiled muscle extracts obtained from yellowtail Seriola quinqueradiata and bastard halibut Paralichthys olivaceus were treated with two kinds of purified enzymes (acid phosphatase and glutamate decarboxylase), and the change in contents of nucleotides, related compounds, and free amino acids was examined. The change in taste qualities was also investigated by a taste test. The enzyme treatment resulted in a marked decrease in the contents of such umami substances as inosine 5′-monophosphate (IMP) and glutamic acid (Glu). The taste test revealed that the treatment of these fish muscle extracts with both or either of the enzymes caused a sharp decrease in umami intensity and also an increase in sourness but not a change in pH. The treatment also effected marked decreases in thickness and overall taste intensity. These findings suggest that IMP and Glu function not only to intensify the thickness and overall taste as well as the umami, but also to repress the sourness sensation elicited by the fish muscle extracts.     

Atrial natriuretic peptide in the dog with mitral regurgitation.

The concentration and molecular form of the plasma atrial natriuretic peptide (ANP) in dogs with mitral regurgitation was investigated. Plasma ANP concentration in dogs with mitral regurgitation was significantly increased (29.4 +/- 1.88 pmol litre-1, n = 40) compared to that in the controls (14.5 +/- 0.62 pmol litre-1, n = 20, P less than 0.01). Molecular forms of plasma ANP were determined by the gel permeation chromatogram. A single peak corresponding to alpha-ANP was detected in the plasma from the controls. However, a peak corresponding to beta-ANP and, or, gamma-ANP was detected in the plasma of the dogs with mitral regurgitation in addition to alpha-ANP. These results suggest that the process of ANP synthesis was altered and excretion of ANP from the heart was enhanced in dogs with mitral regurgitation.     

Regulation of LH synthesis and release by GnRH and gonadal steroids in masu salmon

The roles of salmon GnRH (sGnRH) and gonadal steroid hormones in regulation of LH synthesis and release were examined in primary pituitary cell cultures of masu salmon (Oncorhynchus masou). Pituitaries were taken from fish at four reproductive stages: in March (initiation of sexual maturation); May (early maturation); July (pre-spawning); and September (spawning period). Amounts of LHβ subunit mRNA in the pituitary cells were determined by real-time PCR, and LH levels in the medium were determined by RIA. sGnRH and gonadal steroids including estradiol-17β (E2), testosterone (T) and 11-ketotestosterone (11-KT) were added to the cultures to examine their direct effects on LH response. sGnRH had no significant effect on LHβ mRNA levels at any stages, although a stimulatory trend was noted in March. In contrast, E2 and T considerably increased LHβ subunit mRNA levels in March and May during initial stages of maturation, and the effects were less pronounced in July and September. On the other hand, sGnRH stimulated LH release at all stages in the males and the effects were most prominent in July and September. E2 and T also stimulated LH release in July and September, but their effects were weaker than that of sGnRH. The present results indicate that sGnRH and gonadal steroids directly regulate LH synthesis and release in masu salmon pituitary cells: sGnRH mainly stimulates LH release in the late stage of sexual maturation; whereas, E2 and T are effective in stimulating LH synthesis at earlier stages of maturation.     

Polar cardenolide monoglycosides from stems and twigs of Nerium oleander and their biological activities

Twelve polar cardenolide monoglycosides, 1, 2, 4?C13, and oleagenin (3) were isolated from the methanol extract of stems and twigs of Nerium oleander. Among these, oleagenin (3) and cardenolide monoglycosides named cardenolide B-1 (1) and cardenolide B-2 (2) were isolated from natural sources for the first time. The in vitro antiinflammatory activity of compounds 1?C13 was examined on the basis of inhibitory activity against the induction of the intercellular adhesion molecule-1 (ICAM-1). Compounds 4?C7 were active at an IC₅₀ value of less than 0.4 ??M. The cytotoxic activity of compounds 1?C13 was evaluated against three human cell lines: normal human fibroblast cells (WI-38), malignant tumor cells derived from WI-38 (VA-13), and human liver tumor cells (HepG2). Compounds 4, 6, and 7 were active toward these three cell lines at IC₅₀ values of less than 0.7 ??M, and compounds 5 and 8 were active toward the cell lines at IC₅₀ values of less than 1.5 ??M. The multidrug resistance (MDR) cancer-reversal activity of compounds 1?C13 was evaluated on the basis of the amount of calcein accumulated in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compound 1 and 12 showed significant effects on calcein accumulation.     

Superelastic effect in polycrystalline ferrous alloys

In superelastic alloys, large deformation can revert to a memorized shape after removing the stress. However, the stress increases with increasing temperature, which limits the practical use over a wide temperature range. Polycrystalline Fe-Mn-Al-Ni shape memory alloys show a small temperature dependence of the superelastic stress because of a small transformation entropy change brought about by a magnetic contribution to the Gibbs energies. For one alloy composition, the superelastic stress varies by 0.53 megapascal/°C over a temperature range from -196 to 240°C.     

High-speed atomic force microscopy reveals rotary catalysis of rotorless F₁-ATPase

F(1) is an adenosine triphosphate (ATP)-driven motor in which three torque-generating β subunits in the α(3)β(3) stator ring sequentially undergo conformational changes upon ATP hydrolysis to rotate the central shaft γ unidirectionally. Although extensive experimental and theoretical work has been done, the structural basis of cooperative torque generation to realize the unidirectional rotation remains elusive. We used high-speed atomic force microscopy to show that the rotorless F(1) still "rotates"; in the isolated α(3)β(3) stator ring, the three β subunits cyclically propagate conformational states in the counterclockwise direction, similar to the rotary shaft rotation in F(1). The structural basis of unidirectionality is programmed in the stator ring. These findings have implications for cooperative interplay between subunits in other hexameric ATPases.