Tissue culture of feline normal mammary gland

To study the growth and morphology of feline mammary epithelial cells in vitro, normal feline mammary tissues as well as cells collected from feline milk were cultured and examined using phase-contrast microscopy and immunohistochemistry. The method employed was a modification of Hiratsuka et al., and was found to be useful for the culture of dissociated feline mammary tissue. Small polygonal cells and large spindle-shaped cells that were positively stained with anti-keratin and anti-actin antibodies formed colonies with a pavement-like structure in culture of mid-pregnant mammary gland. Cultures of involuting mammary gland were composed mainly of small spindle-shaped cells, which were negative for keratin immunostaining and thought to be fibroblasts. Myofibroblasts, which participate in feline mammary carcinogenesis, and show keratin negative, actin positive, were not encountered in the present culture system of normal mammary gland. The cells from milk formed small colonies, but did not grow to reach confluent monolayer.     

Studies on wetting phenomena on plant leaf surfaces. 3: A retention model for droplets on solid surfaces

To investigate the factors governing retention of pesticidal spray solutions on plant surfaces, a new retention model for droplets on solid surfaces has been introduced as where ΔΘ = Θ_a – Θ_r. The minimum sliding volumes (MiSV) of surfactant aqueous solutions (2 g litre^?-1; surface tensions; 28·5 – 72·5 mN m^?-1) on smooth surfaces of paraffin wax and polymer sheets were measured and the validity of the above retention equation was verified on combinations of these solutions and surfaces. A concept of the specific adhesional force (F_a) of a droplet was defined as which was the maximum adhesional force on a unit length of the width of the contact circle of a droplet, and F_a values of the solutions on the surfaces were compared. The predominant factors for droplet retention are discussed on the basis of this model.     

Photosynthetic induction responses to variable light under field conditions in three species grown in the gap and understory of a Fagus crenata forest

Photosynthetic induction responses to abrupt increases in photon flux density (PFD) to 800 and 1500 &mgr;mol m(-2) s(-1) from either darkness or 100 &mgr;mol m(-2) s(-1) were examined in situ in leaves of Fagus crenata Blume, Daphniphyllum humile Maxim., and Acer rufinerve Siebold & Zucc. growing in a gap and the understory of an F. crenata forest. Among the species studied, F. crenata exhibited the highest assimilation rate (A(100)), stomatal conductance (g(s100)) at the background PFD of 100 &mgr;mol m(-2) s(-1), and A(100)/A(max) (A(max) = maximum assimilation rate), in both the gap and the understory. Time required for full induction depended on both background PFD and maximum PFD. The induction period was 2-4-fold shorter at a background PFD of 100 &mgr;mol m(-2) s(-1) than in darkness. For the three understory species, time required to full induction was 2-3-fold longer when irradiance was increased from darkness to 800 &mgr;mol m(-2) s(-1) than when irradiance was increased from darkness to 1500 &mgr;mol m(-2) s(-1). Acer rufinerve showed higher initial stomatal conductance (g(s0)) and a shorter induction period in the understory than in the gap. Fagus crenata exhibited a similar g(s0) and induction period in both habitats. Daphniphyllum humile demonstrated lower g(s0) and a longer induction period in the understory than in the gap. These findings indicate that initial stomatal conductance is closely correlated with the photosynthetic induction response. We conclude that the photosynthetic induction response is affected by the light conditions experienced by plants before the sudden increase in irradiance and by the extent of the increase in irradiance.     

Low molecular weight silicic acid – inorganic compound complex as wood preservative

A new wood preservative containing low molecular weight and low-toxicity silicic acid (LWSA) was investigated. To prevent environmental pollution with the wood preservative, a silicic acid monomer aqueous solution (SAMS) or colloidal silicic acid solution (CSAS) was combined with various metal compounds or boric acid. Agents where SAMS or CSAS was combined with boric acid gave good protection against decay caused by the brown-rot fungus Fomitopsis palustris, the treated wood (Cryptomera japonica D. Don) specimens after the leaching test maintained a high resistance to decay. The leaching and decay tests revealed high quantities of chemicals leaching from wood treated with SAMS-metal agents. However, when wood was treated with SAMS-boric acid, there was little leaching of agent in either test. The mechanism of resistance of wood, which was treated with boric acid mixed with CSAS or SAMS, to the brown-rot fungus F. palustris were investigated. When the concentration of boric acid was high, mycelial growth was inhibited completely and no protein production was detected. When the amount of boric acid was low, the xylanase, mannase and cellulase activities were lower than with control wood powder. When powdery boric acid was combined with CSAS, it was considered that the treated woods have higher anti-weather properties than when boric acid-methanol solution was mixed with CSAS. The agent-preparation method adopted should be considered carefully after taking the treatment process and the intended use of the preservative-treated wood into account. Received 26 September 2000 This study was supported by a Grant-in-Aid (09460079) for Scientific Research from the Ministry of Education, Science, and Culture of Japan.     

Influence of coating properties on paper-to-paper friction of coated paper

Coated paper-to-coated paper friction properties were examined in relation to printing runnability difficulties like erroneous double feeding of paper sheets. Higher ratios of precipitated calcium carbonate (PCC) to clay in mixed pigment coatings resulted in higher static and kinetic coefficients of friction (COFs). Microroughness in the order of pigment particle size is considered to relate to COF, because cube-shaped particles of PCC resist sliding. Calendering decreased COF at larger amounts of PCC, but did not change COF of the sole clay formulation at all. Addition of ground calcium carbonate (GCC) decreased COF. The rate of decrease in kinetic COF with increasing number of sliding for the GCC-rich formulation was higher than that for the PCC-rich formulation, presumably because protruding parts, characteristic of the GCC-rich formulation, on the surface were selectively flattened. Addition of styrene-butadiene (SB)-latex up to 14pph decreased COF, but static COF had the highest value at 18pph. The antislip property (as a rubber) of SB-latex developed only in the static mode. Among lubricants formulated, the wax type decreased COF the most remarkably with more effect on kinetic COF than on static COF. Part of this report was presented at the 11th International Printing and Graphic Arts Conference, Bordeaux, France, October 2002     

Effect of Japan Sea climate on geographic distribution ofCastanopsis sieboldii andC. cuspidata

The geographic distributions ofCastanopsis sieboldii andCastanopsis cuspidata overlap each other on the Pacific coast of Japan, but on the Japan Sea coastC. sieboldii tends to dominate at similar temperatures. The authors attempted to explain this phenomenon by analyzing the effects of climatic factors. Nuts were collected from the Pacific and Japan Sea coasts of the Kinki and Chugoku districts, and the nut characteristics and the number of layers of epidermis in the leaves of the seedlings were investigated. The distribution ofC. sieboldii andC. cuspidata was satisfactorily explained by a multiple regression equation that was developed using three climatic factors: maximum snow depth in winter, lowest temperature in the coldest month, and annual mean temperature, out of fourteen such factors that were considered. The estimated distribution ofC. sieboldii andC. cuspidata from the multiple regression equation agreed with 66.2% of the actual observations.     

A dwarf bamboo (<Emphasis Type="Italic">Pleioblastus chino</Emphasis>) and winter browsing by Japanese hare (<Emphasis Type="Italic">Lepus brachyurus</Emphasis>) combine to limit establishment of transplanted native tree seedlings in an abandoned agricultural field

Natural forest recovery on abandoned farmland is hindered by a variety of factors and active restoration plays an important role when quick afforestation is desired. We investigated seedling survival of four transplanted native tree species (Quercus myrsinifolia, Quercus serrata, Aphananthe aspera, and Rhus sylvestris) by experimentally manipulating the vegetation cover, which was mainly dominated by dwarf bamboo (Pleioblastus chino), and herbivore access to the planting sites on farmland that had been abandoned for 15 years at the start of the study. Few transplanted seedlings of any species survived under intact vegetation cover, irrespective of herbivore presence. In gaps in the vegetation cover, winter browsing by Japanese hare (Lepus brachyurus) damaged all species. However, lower browsing frequency and higher resprouting ability after grazing of the seedlings enabled both Quercus species to survive better than the other species. These results indicate that dwarf bamboo and the hare jointly limit the establishment of native trees in old fields. If active afforestation by transplanting seedlings at sites dominated by dwarf bamboo is planned, a combination of vegetation removal, selection of suitable species, and temporary seedling protection will be most effective.     

Simultaneous analysis of catechins, gallic acid, strictinin, and purine alkaloids in green tea by using catechol as an internal standard

We developed a high-performance liquid chromatography-based method for simultaneous analysis of nine catechins, gallic acid, strictinin, caffeine, and theobromine in green tea by using catechol as an internal standard. Although the high cost and instability of the catechin reference standards limit the application of this method, the addition of ascorbic acid to the standard stock solution preserved the stability of the reference standards in the solution for 1 year when stored at -30 degrees C. Furthermore, we found that the slopes of the calibration curves plotted were stable for a run time of 2000 h. Our method proved to be appropriate for quantification and yielded good correlation coefficients, detection levels, repeatability, reproducibility, and recovery rates. Quantitative data revealed that the contribution of only 200 mL of brewed tea to the total dietary catechins was approximately 220-420 mg, while that of 500 mL of bottled tea was approximately 170-900 mg.     

Analysis of acrylamide in green tea by gas chromatography-mass spectrometry

Optimization of the solid-phase extraction cleanup procedure enabled the GC-MS analysis of acrylamide in tea samples without the interference of bromination by tea catechins. Although polyvinylpolypyrrolidone (PVPP) is available for removing tea catechins from tea extract, the peaks derived from PVPP had the same retention time as brominated acrylamide in mass chromatograms obtained by GC-MS. A considerable amount of acrylamide was formed at roasting temperatures of > or =120 degrees C; the highest acrylamide level was observed when tea samples were roasted at 180 degrees C for 10 min. Higher temperatures and longer processing times caused a decrease in the acrylamide content. Furthermore, an analysis of 82 tea samples showed that rather than the reducing sugar content, the asparagine content in tea leaves was a significant factor related to acrylamide formation in roasted products. The acrylamide level in roasted tea products was controlled by asparagine in the presence of reducing sugars.     

Cellular localization of IL-18 and IL-18 receptor in pig anterior pituitary gland

Pro-inflammatory cytokine interleukin 18 (IL-18) has been proposed to have a role in modulating immuno-endocrine functions. Our previous study showed that IL-18 and IL-18 receptor (IL-18R) colocalized in somatotrophs of the bovine anterior pituitary gland, and the possibility that IL-18 acts on somatotrophs as an autocrine factor. In the present study, we investigated the localization of IL-18 and IL-18R in the pig anterior pituitary gland. RT-PCR analysis showed the expression of IL-18 and IL-18R mRNAin the pig anterior pituitary gland. Immunohistochemistry of IL-18 and specific hormones revealed the presence of IL-18 in somatotrophs, mammotrophs, thyrotrophs and gonadotrophs. IL-18R was localized in somatotrophs and thyrotrophs. Furthermore, the somatotrophs immunoreactive for IL-18 did not contain IL-18R. Thus, IL-18R and IL-18 were not colocalized in an identical somatotroph. These findings suggest that the localization of IL-18 in pig somatotrophs is different from that in bovine somatotrophs, although IL-18 closely associates with somatotrophs in the anterior pituitary glands in both species.