Growth changes of the collagen content and architecture in the pectoralis and iliotibialis lateralis muscles of cockerels

1. Growth changes of the collagen content and architecture in the pectoralis (PT) and iliotibialis lateralis (ITL) muscles were examined using cockerels from 1 to 14 weeks of age. 2. Total collagen content in PT muscle showed little change, but in ITL muscle reached a maximum at 5 weeks and thereafter decreased slightly until 14 weeks. The collagen content was markedly larger in ITL muscle after 5 weeks. Pyridinoline content of collagen increased abruptly from 5 to 14 weeks in both muscles, but no difference between muscle types was detected. 3. The cell size of the endomysial honeycombs increased with the development of myofibres, and the mesh size of the perimysium around the honeycombs enlarged. 4. In both muscles endomysia were an incomplete network of collagen fibrils with many foramina at one week, became a very thin membrane of felt-like fabric in 2 to 5 weeks and thereafter increased in thickness until 11 to 14 weeks. 5. Perimysial width around the secondary fasciculus differed between the muscle types after 5 weeks. In the wider perimysium of ITL muscle, the collagen fibres increased in number and size to make a stack of collagen bands around the fasciculus. In the narrower perimysium of PT muscle, a few platelets of collagen fibres also developed. 6. The perimysial collagen fibre at 1 to 2 weeks had a smooth surface and appeared to be composed of fine collagen fibrils. The fibre at 11 to 14 weeks showed a rugged surface and was composed of coarser collagen bundles that combined with each other into a net-like configuration with very slim meshes. 7. Our results showed that the collagenous components of chicken intramuscular connective tissue changed markedly during the early period of muscle growth in distribution, architecture and quality but with little difference in quantity.     

Fixation to the canine bone of artificial implant with new surface structure

Screw and laser (SL) column by making screw threads and forming small holes using laser irradiation on the base metal and conventional beads coating (BC) columns were embedded into the shaft of canine femurs, and compared the implant fixation to the host bone. The interfacial strength in SL columns was almost equivalent as BC columns, and bone-column contact rate was higher than BC columns significantly at twelve weeks after implantation. The newly devised SL surface had almost equivalent bone fixation strength comparable to the conventional BC surface. Also, this surface should provide a useful porous surface for use in artificial joints since there is no risk of surface structure detachment.     

Distributive and phagocytic characteristics of hepatic macrophages in five cetaceans belonging to Delphinidae and Ziphiidae

Details of morphology and distribution of hepatic macrophages in cetaceans were investigated using the immunohistochemistry with an antibody (SRA-E5) generated against human macrophage scavenger receptor antigen. Liver samples were obtained from five species of cetaceans (Baird's beaked whales, short-finned pilot whales, Risso's dolphins, bottlenose dolphins, and pantropical spotted dolphins). Except for two species of whales, the number of SRA-E5-positive Kupffer cells was greatest in the perivenous zone (zone 3), followed by the mid-zonal (zone 2) and periportal (zone 1) zones; this distribution pattern was different from that in cattle examined here and previously reported rodents with the highest number in zone 1. The frequency of Kupffer cell in each of zones was significantly different among species, and interestingly, the total mean of the Kupffer cell number in three zones increased as the body-length of species was small. In cetaceans, Kupffer cells in zone 1 appeared larger and more stellate in shape, whereas those in zone 3 were smaller and rounder. All cetaceans but Baird's beaked whales had the black pigment-containing Kupffer cells, with the greatest number in zone 3, and macrophages with the similar pigments were also seen in the hepatic intermediate septa, indicating an active phagocytosis. Most of the black pigments were considered to be lipofuscin and such pigments were not seen in the bovine livers. These results indicate that cetacean hepatic macrophages show differences in the distribution and phagocytosis among hepatic lobular zones, or between cetacean species and terrestrial animals.     

Establishment and characterization of four canine melanoma cell lines

Four canine melanoma cell lines were established from the subcutaneous, oral gingival and mucosal melanoma tissues at the primary and metastatic sites. These cell lines were designated as CMeC-1, CMeC-2, KMeC and LMeC. The cells were spindles in shape, similar to that of primary tumor cells. The doubling times of these cells ranged from 34.1 +/- 5.61 to 57.9 +/- 3.28 hr and their chromosome number ranged from 46 to 80. When transplanted into nude mice, CMeC-1 and LMeC produced tumors, whereas CMeC-2 and KMeC did not. The morphology of the tissue formed by xenotransplantation of these cells was similar to their primary tumors.     

Design of hammerhead ribozymes that cleave murine Sry mRNA in vitro and in vivo

As the first step in investigating the possiblity of applying ribozyme technology to artificial control of the sex ratios at birth in farm animals, where the demand for females exceeds that for males, we designed a hammerhead ribozyme (HHRz) and 2 tRNA(val)-hammerhead ribozyme complexes (tRNARz3 and tRNARz4), and examined their effects upon murine Sry mRNA in vitro and in cells. We demonstrated that HHRz and tRNARz3 could effectively cleave the target Sry mRNA in vitro. For the purpose of experiments in vivo, HHRz was cloned into the highly efficient pUC-CAGGS mammalian expression vector (pCAG/HHRz), and the tRNA ribozyme complexes were cloned into the pol III promoter-driven pPUR-KE vector (pPUR/tRNARz3 and pPUR/tRNARz4); the ribozyme vectors were co-transfected with the target vector (pCAG/Sry). A suppressive action (up to approx. 60%) was confirmed for pCAG/HHRz and pPUR/tRNARz3 upon the transiently expressed exogenously introduced Sry in M15 cultured cells.     

Rapamycin-induced insulin resistance is mediated by mTORC2 loss and uncoupled from longevity

Rapamycin, an inhibitor of mechanistic target of rapamycin complex 1 (mTORC1), extends the life spans of yeast, flies, and mice. Calorie restriction, which increases life span and insulin sensitivity, is proposed to function by inhibition of mTORC1, yet paradoxically, chronic administration of rapamycin substantially impairs glucose tolerance and insulin action. We demonstrate that rapamycin disrupted a second mTOR complex, mTORC2, in vivo and that mTORC2 was required for the insulin-mediated suppression of hepatic gluconeogenesis. Further, decreased mTORC1 signaling was sufficient to extend life span independently from changes in glucose homeostasis, as female mice heterozygous for both mTOR and mLST8 exhibited decreased mTORC1 activity and extended life span but had normal glucose tolerance and insulin sensitivity. Thus, mTORC2 disruption is an important mediator of the effects of rapamycin in vivo.     

A tripartite standards regime analysis of the contested development of a sustainable agriculture standard

As concerns over the negative social and environmental impacts of industrial agriculture become more widespread, efforts to define and regulate sustainable agriculture have proliferated in the US. Whereas the USDA spearheaded previous efforts, today such efforts have largely shifted to Tripartite Standards Regimes (TSRs). Using a case study of the Leonardo Academy’s initiative to develop a US sustainable agriculture standard, this paper examines the standards-development process and efforts by agribusiness to influence the process. Specifically, we analyze how politics operate in seemingly “depoliticized” TSRs, and how agribusiness and the USDA use “framing practices” and procedural complaints to influence the standard-development process. We contend that although governance mechanisms are a potentially powerful tool for advocates of alternative agrifood, their efficacy may be constrained by science-based requirements, an agribusiness countermovement, and a captured state.