Mitogenesis in response to PDGF and bombesin abolished by microinjection of antibody to PIP2

The turnover of phosphatidylinositol 4,5-bisphosphate (PIP2) is believed to constitute a crucial step in the signaling pathways for stimulation of cells by a variety of bioactive substances, including mitogens, but decisive evidence for the idea has not been obtained. In the present study, a monoclonal antibody to PIP2 was microinjected into the cytoplasm of NIH 3T3 cells before or after exposure to mitogens. The antibody completely abolished nuclear labeling with [3H]thymidine induced by platelet-derived growth factor and bombesin, but not by fibroblast growth factor, epidermal growth factor, insulin, or serum. The findings strongly suggest that PIP2 breakdown is crucial in the elicitation and sustaining of cell proliferation induced by some types of mitogens such as platelet-derived growth factor and bombesin.     

Propolypeptide of von Willebrand factor circulates in blood and is identical to von Willebrand antigen II

The generally mild bleeding disorder of von Willebrand disease is associated with abnormalities of two distinct plasma proteins, the large multimeric von Willebrand factor (vWF), which mediates platelet adhesion, and von Willebrand antigen II (vW AgII), which is of unknown function. The two proteins were found to have a common biosynthetic origin in endothelial cells and megakaryocytes, which explains their simultaneous absence in the severe form of this hereditary disease. Shared amino acid sequences from a 100-kilodalton plasma glycoprotein and from vW AgII are identical to amino acid sequences predicted from a complementary DNA clone encoding the 5' end of vWF. In addition, these proteins have identical molecular weights and immunologic cross reactivities. Monoclonal antibodies prepared against both proteins recognize epitopes on the pro-vWF subunit and on a 100-kilodalton protein that are not present on the mature vWF subunit in endothelial cell lysates. In contrast, polyclonal antibodies against vWF recognize both pro-vWF and vWF subunits. Thus, the 100-kilodalton plasma glycoprotein and vW AgII are identical proteins and represent an extremely large propolypeptide that is first cleaved from pro-vWF during intracellular processing and then released into plasma.     

Immune response during the onset of coliform mastitis in dairy cows vaccinated with STARTVAC®

The immune response during the onset of coliform mastitis in vaccinated cows was investigated by measuring lactoferrin (LF), interleukin-8 ( IL-8), and interleukin-1β (IL-1β) concentrations and somatic cell counts in 28 milk samples at the onset of acute coliform mastitis (ACM) and 73 milk samples at the onset of peracute coliform mastitis (PCM). Vaccinated ACM, unvaccinated ACM, and vaccinated PCM showed significantly higher values for LF and IL-1β levels than unvaccinated PCM (p < .01). The IL-8 concentration was lower in vaccinated PCM than in unvaccinated PCM (p < .05). There was no significant difference in somatic cell counts for each parameter. There were no significant differences in the parameters between vaccinated and unvaccinated ACM cows, or vaccinated ACM and PCM cows. From the above results, it is suggested that mastitis vaccination improved the early immune response, particularly at the onset of PCM, and played a large role in host defense against the initial infection.     

Comparative pathogenicity study on antigenically variant strains of Enterococcus seriolicida

Enterococcus seriolicida strains were divided into two groups, agglutinating and nonagglutinating, by a slide agglutination test using antiserum against the YT-3 strain. Intraperitoneal injection of agglutinating and nonagglutinating strains into yellowtail, Seriola quinqueradiata Temminck & Schlegel, revealed that nonagglutinating strains were more virulent than agglutinating strains. Two nonagglutinating and highly pathogenic strains SS91–014 and SS91–092 were subcultured 30 times in brain heart infusion broth, and the agglutination titres of 50 colonies from subcultures 1, 2, 3, 4, 5, 6, 11, 16, 21, 26 and 30 against anti-YT-3 serum were determined. Transformation from a nonagglutinating (1:<4) to an agglutinating (1: ≥4) pattern was first observed at the sixteenth subculture, and the ratio of agglutinating to nonagglutinating substrains rose until the thirtieth subculture. At this time, 70% of the SS91–014 population and 52% of the SS91–092 population were transformed to an agglutinating pattern. When the pathogenicity of four transformed substrains with different agglutination titres was tested in yellowtail, the nonagglutinating substrain showed higher pathogenicity than the agglutinating substrains, but no relationship between LD₅₀ values and the agglutination titres of transformed substrains was observed. The pathogenicity of E. seriolicida appears to be related to the agglutination pattern, although it was not demonstrated that this property is solely responsible for pathogenicity.     

Establishment and characterization of two new cell lines derived from flounder, Paralichthys olivaceus (Temminck & Schlegel)

Two new cell cultures from flounder, Paralichthys olivaceus (Temminck & Schlegel), flounder fin (FFN) cells from fin tissue and flounder spleen (FSP) cells from spleen tissue, were established and characterized. The cells multiplied well in Eagle's minimum essential medium, supplemented with 10% foetal bovine serum, and have been subcultured more than 100 times, becoming continuous cell lines. Modal diploid chromosome number of FFN and FSP cells was 64 and 62, respectively. Polymerase chain reaction products were obtained from FFN and FSP cells with primer sets ofmicrosatellite markers of flounder. Optimal growth temperature was 20 degrees C and consisted of epithelioid cells. FFN and FSP cells showed cytopathic effects after inoculation of infectious pancreatic necrosis virus, marine birnavirus, chum salmon virus, infectious haematopoietic necrosis virus, spring viraemia of carp virus and hirame rhabdovirus. Thus these new cell lines may be useful for studying a wide range of fish viruses.     

Modeling of a cylindrical laminated veneer lumber I: mechanical properties of hinoki (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>) and the reliability of a nonlinear finite elements model of a four-point bending test

The use of low-grade logs to build spirally wound laminated veneer lumber (LVL) has been studied and improved from the point of view of the gluing process, fiber orientation angle, and end joint of the LVL. The butt joint appears to be the fracture point when the column is submitted to a compressive or bending load. Owing to the complexity of cylindrical LVL, we used a finite element method to simulate the mechanical behavior of part of its wall. This part was small enough to be considered flat but was representative of the structure, especially in the area of the butt joint. This allowed us to test the validity of different settings of the parameters involved in the manufacturing process. To feed data for this model, we used the results established for the linear and nonlinear behavior of raw hinoki in Part I of this series of articles. We then used this numerical model to improve the quality of the butt joint by testing different settings of the joint. We show that reducing the butt joint gap under 0.5 mm, which requires only a few changes in the production line, provides an important increase in the modulus of upture and nonnegligible improvement of the modulus of elasticity compared to that for a ≥ 1 mm butt joint gap.     

Modeling of a cylindrical laminated veneer lumber II: a nonlinear finite element model to improve the quality of the butt joint

The use of low-grade logs to build spirally wound laminated veneer lumber (LVL) has been studied and improved from the point of view of the gluing process, fiber orientation angle, and end joint of the LVL. The butt joint appears to be the fracture point when the column is submitted to a compressive or bending load. Owing to the complexity of cylindrical LVL, we used a finite element method to simulate the mechanical behavior of part of its wall. This part was small enough to be considered flat but was representative of the structure, especially in the area of the butt joint. This allowed us to test the validity of different settings of the parameters involved in the manufacturing process. To feed data for this model, we used the results established for the linear and nonlinear behavior of raw hinoki in Part I of this series of articles. We then used this numerical model to improve the quality of the butt joint by testing different settings of the joint. We show that reducing the butt joint gap under 0.5 mm, which requires only a few changes in the production line, provides an important increase in the modulus of upture and nonnegligible improvement of the modulus of elasticity compared to that for a ≥ 1 mm butt joint gap.     

A Case Study on Estimation of Dry Deposition of Sulfur and Nitrogen Compounds by Inferential Method

In order to estimate dry deposition, deposition velocity calculation and concentration measurement were carried out in Niigata, Japan. Deposition velocities of SO₂ and HNO₃ for some surfaces such as coniferous forest, deciduous forest, agricultural land, and water were calculated taking into account diurnal variations of meteorological elements using routine meteorological data. Deposition velocities of fine and coarse aerosols were also estimated respectively. Concentrations of SO₂, HNO₃, sulfate and nitrate in fine and coarse aerosols respectively were measured from July to December in 1998 using filter pack and denuder methods. The results indicate that HNO₃ dry deposition for the high aerodynamic roughness surfaces such as forests is quite large. It is suggested that sulfate and nitrate aerosols depositions as well as the gases depositions should be taken into account to estimate dry deposition of sulfur and nitrogen compounds. It is also indicated that dry depositions of sulfur and nitrogen compounds are unable to ignore compared with their wet depositions.     

Altered leukocyte responsiveness in dairy cows with naturally occurring chronic Staphylococcus aureus mastitis

Changes in inflammatory parameters, leukocyte surface markers, functional responses and cytokine mRNA expression of leukocytes of dairy cows with naturally occurring chronic Staphylococcus aureus (S. aureus) mastitis and healthy cows were determined to elucidate the leukocyte responses to S. aureus infection of the mammary gland. Increased values in inflammatory parameters and matrix metalloproteinase activities in milk revealed the characteristics of cows with chronic mastitis. Expression of L-selectin and CD18 molecules on neutrophils and proportion of CD8 cells in milk from cows with S. aureus mastitis were significantly (P<0.05) increased compared with those found in healthy cows. The FcR-stimulated CL response of blood neutrophils was significantly (P<0.05) decreased in cows with S. aureus mastitis. Significantly (P<0.05) decreased mitogenic responses of lymphocytes were found in cows with S. aureus mastitis; however, the values were not restored to those of healthy cows when stimulated with both mitogens and the cytokine IL-1β. The mRNA expression of TNF-α, IL-1β and IL-8 on milk leukocytes from cows with S. aureus was found to be increased compared with that of healthy cows. The changes of immune responses found in cows with S. aureus mastitis appear to be influenced by the severity and duration of inflammation in infected quarters. The down-regulation of the leukocyte functions found in cows with S. aureus mastitis appears to be associated with the progress of the chronic stage of S. aureus mastitis.     

Effects of high ambient temperature on urea‐nitrogen recycling in lactating dairy cows

Effects of exposure to hot environment on urea metabolism were studied in lactating Holstein cows. Four cows were fed ad libitum a total mixed ration and housed in a temperature‐controlled chamber at constant moderate (18°C) or high (28°C) ambient temperatures in a cross‐over design. Urea nitrogen (N) kinetics was measured by determining urea isotopomer in urine after single injection of [¹⁵N₂]urea into the jugular vein. Both dry matter intake and milk yield were decreased under high ambient temperature. Intakes of total N and digestible N were decreased under high ambient temperature but urinary urea‐N excretion was increased. The ratio of urea‐N production to digestible N was increased, whereas the proportion of gut urea‐N entry to urea‐N production tended to be decreased under high ambient temperature. Neither return to the ornithine cycle, anabolic use nor fecal excretion of urea‐N recycled to the gut was affected by ambient temperature. Under high ambient temperature, renal clearance of plasma urea was not affected but the gut clearance was decreased. Increase of urea‐N production and reduction of gut urea‐N entry, in relative terms, were associated with increased urinary urea‐N excretion of lactating dairy cows in higher thermal environments.