Ability of salmon growth hormone to accelerate somatic growth of juvenil abalone Haliotis discus hannai

ABSTRACT:   The ability of salmon growth hormone (sGH) to accelerate the somatic growth of juvenile abalone Haliotis discus hannai by immersion was examined. After immersion for one hour into a sGH-rich solution at a concentration of 30 mg/L, the sGH immunoreactivity in the body fluid of abalone was maximal after one day, and levels were still detectable at two days. No immunoreactivity was observed in the control group. Following immersion for one hour at one or two-week intervals for 120 weeks into the sGH-rich solution at 30 mg/L, the sGH-immersed abalone exhibited a significant increase in shell length and body weight. On the other hand, abalone immersed into a salmon prolactin (sPRL)-rich solution at 30 mg/L for one hour showed a lower increase in both shell length and body weight than the sGH-immersed abalone. No increases in shell length and body weight were observed in either the bovine serum albumin-immersed abalone or untreated controls. These results provide evidence that sGH can be transported from ambient water into the circulatory system of abalone, and can subsequently improve the somatic growth of juveniles.     

Concentrations and specific antibodies to staphylococcal enterotoxin-C and toxic shock syndrome toxin-1 in bovine mammary gland secretions,and inflammatory response to the intramammary inoculation of these toxins

To investigate the pathological role of staphylococcal enterotoxins (SEs) and toxic shock syndrome toxin-1 (TSST-1) in bovine mastitis, the production of SEs and TSST-1 was investigated in staphylococci isolated from 120 mammary gland secretions (MGS, 51 from no clinical sign-mammary glands and 69 from staphylococcal mastitic-mammary glands) collected from dairy farms where staphylococcal mastitis frequently occurred in Miyagi and Yamagata prefectures from 1997 to 1998. Concentrations of these toxins and specific antibody titers in each MGS were also measured. Furthermore, SEC and TSST-1 were inoculated into lactating mammary glands and inflammatory responses were analyzed. A high percentage of staphylococci including Staphylococcus aureus and coagulase-negative staphylococci isolated from both no clinical sign- and mastitic-MGS produced both SEC and/or TSST-1. The concentration of SEC increased with the severity of the mastitis, and was significantly higher (P<0.05) in acute mastitic-than in no clinical signs-MGS. Titers of specific antibodies to TSST-1 in MGS were significantly higher (P<0.05) than those to SEC, regardless of whether or not the cows were lactating or mastitic. Specific antibodies purified from MGS neutralized each toxin in vitro. A significant increase (P < 0.05) in somatic cell counts was induced by the intramammary inoculation of SEC but not TSST-1. These findings indicated that SEC rather than TSST-1 plays an important role in the pathology of staphylococcal bovine mastitis. The inflammatory activity of TSST-1 was probably neutralized by specific antibodies in MGS.     

Age trends in the genetic parameters of wood density and the relationship with growth rates in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66. Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth rate because rapid growth will result in a low-density wood product, especially in the early growth period.     

Fundamental studies on wood/cellulose-plastic composites: effects of composition and cellulose dimension on the properties of cellulose/PP composite

Although wood/cellulose-plastic composites (WPC) of low wood/cellulose content have been more accepted worldwide and are promoted as low-maintenance, high-durability building products, composites containing high wood/cellulose content are not yet developed on an industrial scale. In this study, flow properties, mechanical properties, and water absorption properties of the compounds of cellulose microfiber/polypropylene (PP) and maleic anhydride-grafted polypropylene (MAPP) were investigated to understand effects of the high cellulose content and the dimensions of the cellulose microfiber. The molding processes studied included compression, injection, and extrusion. It was found that fluidity is not only dependent on resin content but also on the dimension of the filler; fluidity of the compound declined with increased fiber length with the same resin content. Dispersion of the composite was monitored by charge-coupled device (CCD) microscope. Increasing the plastic content in the cellulose-plastic formulation improved the strength of mold in addition to the bond development between resin and filler, and the tangle of fibers. The processing mode affected the physicomechanical properties of the cellulosic plastic. Compression-molded samples exhibited the lowest modulus of rupture (MOR) and modulus of elasticity (MOE) and the highest water absorption, while samples that were injection-molded exhibited the highest MOR (70 MPa) and MOE (7 GPa) and low water absorption (2%).     

Endothelin: a novel peptide in the posterior pituitary system

Endothelin (ET), originally characterized as a 21-residue vasoconstrictor peptide from endothelial cells, is present in the porcine spinal cord and may act as a neuropeptide. Endothelin-like immunoreactivity has now been demonstrated by immunohistochemistry in the paraventricular and supraoptic nuclear neurons and their terminals in the posterior pituitary of the pig and the rat. The presence of ET in the porcine hypothalamus was confirmed by reversed-phase high-pressure liquid chromatography and radioimmunoassay. Moreover, in situ hybridization demonstrated ET messenger RNA in porcine paraventricular nuclear neurons. Endothelin-like immunoreactive products in the posterior pituitary of the rat were depleted by water deprivation, suggesting a release of ET under physiological conditions. These findings indicate that ET is synthesized in the posterior pituitary system and may be involved in neurosecretory functions.     

Autoimmune disease and impaired uptake of apoptotic cells in MFG-E8-deficient mice

Apoptotic cells expose phosphatidylserine and are swiftly engulfed by macrophages. Milk fat globule epidermal growth factor (EGF) factor 8 (MFG-E8) is a protein that binds to apoptotic cells by recognizing phosphatidylserine and that enhances the engulfment of apoptotic cells by macrophages. We report that tingible body macrophages in the germinal centers of the spleen and lymph nodes strongly express MFG-E8. Many apoptotic lymphocytes were found on the MFG-E8-/- tingible body macrophages, but they were not efficiently engulfed. The MFG-E8-/- mice developed splenomegaly, with the formation of numerous germinal centers, and suffered from glomerulonephritis as a result of autoantibody production. These data demonstrate that MFG-E8 has a critical role in removing apoptotic B cells in the germinal centers and that its failure can lead to autoimmune diseases.     

Effect of dietary addition of seaweed and licorice on the immune performance of pigs

In pig production, dietary additive antibiotics are usually used for growth stimulation and disease prevention, although there is public concern about the increased incidence of resistant antibiotics and food safety. It is possible that such antibiotics might be replaced by naturally derived products such as seaweed and licorice. In this study, we evaluated the effect of dietary addition of seaweed and licorice on enhancing the immune function in swine. The animals of each group (eight animals per group) were sensitized at day 42 and 49, and the immunoglobulin production and the expression of cytokines were detected by the ELISA and real‐time PCR. As the results, saliva IgA production of the seaweed‐treated group increased around five times compared to that of control (day 56). Delayed hypersensitivity reaction and IgG production of the seaweed‐treated group increased around 1.8–2.0 times. In addition, enhanced saliva IgA production was detected at day 50 (around two times) and day 51 (around five times) by the licorice treatment, and lower expression level of tumor necrosis factor‐α messenger RNA at day 51 (around 1/25) was observed in the licorice treatment. We conclude that the replacement of antibiotics by naturally derived dietary additives might be feasible for immune system enhancement.     

The effect of pretreatment with different doses of GnRH to synchronize follicular wave on superstimulation of follicular growth in dairy cattle

The objective of this study was to evaluate the efficiency of gonadotropin releasing hormone (GnRH) and GnRH doses in synchronizing follicular wave emergence as a pretreatment for superovulation in cattle. Fourteen Holstein-Friesian cows 6 days from estrus were randomly assigned to receive 100 microg (n=4), 50 microg (n=5), or 25 microg (n=5) of GnRH. Superovulation was induced with injections of porcine FSH (pFSH) twice daily, decreasing the dose (total 42 AU) over 5 days beginning 2.5 days after receiving GnRH. On the 7th and 8th injections of pFSH, 750 microg of PGF(2alpha) was also given. With the exception of one cow that was given 50 microg of GnRH, ovulation was induced in all cows from the three groups and the new follicular wave emergence was observed. The total number of follicles for the 25 microg GnRH group was less than that observed for the 100 microg GnRH group (P<0.05), although there were no differences between the 100 microg, 50 microg and 25 microg GnRH groups with respect to the number of preovulatory follicles (>or=10 mm) and CL. The numbers of normal embryos were greater for the 25 microg GnRH group than the 100 or 50 microg GnRH groups (P<0.01); however, the numbers of ova/embryos did not differ significantly between the three groups. These results suggest that 25 microg of GnRH was sufficient to induce ovulation and follicular wave emergence. On day 6 of the estrous cycle, a reduction of the dose of GnRH to synchronize follicular wave emergence as a pretreatment for superstimulation promotes transferable embryos.     

Small molecule lactoferrin with an inflammatory effect but no apparent antibacterial activity in mastitic mammary gland secretion

We have identified various lactoferrin (Lf) molecules in mastitic mammary gland secretions (MGSs), and these Lf molecules were examined for their physiological function in MG. These Lf molecules were isolated by Con A affinity chromatography, and then analyzed by various electrophoresis methods and N-terminal amino acid sequencing. The low Con A affinity Lf was found to have low molecular peptides as compared with the 86 kDa of the high Con A affinity Lf, which is usually detected in healthy MGSs. The N-terminal amino acid sequence of each of the small molecular Lfs were confirmed as fragments of 86 kDa Lf. This low Con A affinity Lf stimulated spleen adherent cells to produce more O(2)(-) than 86 kDa Lf. Furthermore, the low Con A affinity Lf showed low antibacterial activity against E. coli and S. aureus, and had decreased iron-binding capacity in comparison with 86 kDa Lf. Moreover, the 86 kDa Lf could stimulate bovine T cells or macrophages to produce IFN-gamma, IL-4, IL-6, and IL-1alpha. However low Con A affinity Lf induced the production of TNFalpha, but not physiological T cell or macrophage cytokines. It was also found that when the healthy MGs of dry cows were injected with the low Con A affinity Lf, there was an increase in polymorphonuclear cells together with TNFalpha, MCP-1, and IL-8 production. These results suggested that low Con A affinity Lf in mastitic MGSs differed from 86 kDa Lf in physiological characteristics, and, that it induced an inflammatory reaction in MGs.