Shigeto Yamashiro

Nickel sulphide-induced rhabdomyosarcomata in rats.

Fifty‐nine Fischer rat tumors and eleven Hooded rat tumors induced by intramuscular injection of Ni3S2 were examined and their histopathologic and cytologic characteristics studied. Nine out of eleven Hooded rat tumors metastasized whereas 15 out of 59 Fischer rat tumors metastasized within 30 days. Histopathological characterization of the Ni3S2‐induced tumors was made according to their preponderant cellular constitution. They were grouped into six types: well‐differentiated rhabdomyosarcomas, poorly‐differentiated rhabdomyosarcomas, embryonal rhabdomyosarcomas, mesenchymal tumors, leiomyosarcoma‐like tumors and fibrosarcoma‐like tumors. Forty‐seven of total of 70 were rhabdomyosarcomas. Tumors with shorter latent periods in Fischer rats and tumors with fleshy and soft texture demonstrated a higher incidence of metastases.

MRI study of the inhibitory effect of new spin traps on in vivo CCl4-induced hepatotoxicity in rats

Acute CCl4 hepatotoxicity is thought to occur as a result of free radicals generated from the metabolism of CCl4 in the liver. With the use of MRI it is possible to detect in vivo a CCl4-induced localized edematous region surrounding the major branch of the hepatic portal vein in the right lobe. Inhibition of the CCl4-induced response has been obtained by pretreatment with the spin trap, PBN, 30 min prior to CCl4 exposure. The inhibitory effect of two new spin traps, M3PO or methyl-DMPO, and PhM2PO or phenyl-DMPO, on in vivo CCl4-induced acute hepatotoxicity was investigated. Both PhM2PO and M3PO were found to inhibit the CCl4-induced response at lower concentrations (0.35 M/kg body weight) than PBN (0.70 M/kg body weight). However, both M3PO and PhM2PO were also found to induce an edematous response at the same concentrations used for the PBN studies (0.70 M/kg body weight). PhM2PO, at a concentration of 0.35 M/kg body weight, was 93% as efficient as PBN, at a concentration of 0.70 M/kg body weight; whereas M3PO, at a concentration of 0.35 M/kg, was 89% as efficient as PBN at 0.70 M/kg body weight. Electron micrographs were obtained from small liver sections taken in proximity to the major branch of the hepatic portal veins of all treatment groups. The electron microscopy investigations support the MRI findings.

Small intestine histomorphometry of beef cattle with divergent feed efficiency.

BackgroundThe provision of feed is a major cost in beef production. Therefore, the improvement of feed efficiency is warranted. The direct assessment of feed efficiency has limitations and alternatives are needed. Small intestine micro-architecture is associated with function and may be related to feed efficiency. The objective was to verify the potential histomorphological differences in the small intestine of animals with divergent feed efficiency.MethodsFrom a population of 45 feedlot steers, 12 were selected with low-RFI (superior feed efficiency) and 12 with high-RFI (inferior feed efficiency) at the end of the finishing period. The animals were processed at 13.79 ± 1.21 months of age. Within 1.5 h of slaughter the gastrointestinal tract was collected and segments from duodenum and ileum were harvested. Tissue fragments were processed, sectioned and stained with hematoxylin and eosin. Photomicroscopy images were taken under 1000x magnification. For each animal 100 intestinal crypts were imaged, in a cross section view, from each of the two intestinal segments. Images were analyzed using the software ImageJ®. The measurements taken were: crypt area, crypt perimeter, crypt lumen area, nuclei number and the cell size was indirectly calculated. Data were analyzed using general linear model and correlation procedures of SAS®.ResultsEfficient beef steers (low-RFI) have a greater cellularity (indicated by nuclei number) in the small intestinal crypts, both in duodenum and ileum, than less efficient beef steers (high-RFI) (P < 0.05). The mean values for the nuclei number of the low-RFI and high-RFI groups were 33.16 and 30.30 in the duodenum and 37.21 and 33.65 in the ileum, respectively. The average size of the cells did not differ between feed efficiency groups in both segments (P ≥ 0.10). A trend was observed (P ≤ 0.10) for greater crypt area and crypt perimeter in the ileum for cattle with improved feed efficiency.ConclusionImproved feed efficiency is associated with greater cellularity and no differences on average cell size in the crypts of the small intestine in the bovine. These observations are likely to lead to an increase in the energy demand by the small intestine regardless of the more desirable feed efficiency.

GROWTH AND CYTOGENETIC CHARACTERISTICS OF NICKEL SULPHIDE-INDUCED RHABDOMYOSARCOMAS IN RATS

Rhabdomyosarcomas induced by single intramuscular injections of nickel sulphide (Ni3S2) in Fischer and Hooded rats were cultured in vivo and and in vitro to study their growth characteristics and chromosomal constitution. The tumor cell suspensions cultured in vitro exhibited more myogenic differentiation on the coverslips than those cells grown in vivo in diffusion chambers. A characteristic feature of in vivo cultures was the appearance of microclusters which resembled the primary tumors.

Additional vitamin E required in milk replacer diets that contain canola oil.

Abstract It is known that ingestion of oils containing polyunsaturated fatty acids (PUFA) of the n-3 and n-6 series results in a high degree of unsaturation in membrane phospholipids which in turn may increase lipid peroxidation, cholesterol oxidation, free radical accumulation and membrane damage. Vitamin E is a powerful inhibitor of lipid peroxidation induced by free radical damage to cell membranes and is an essential component of milk replacers. In the experiments reported here, neonatal piglets raised on canola oil based milk replacer diets supplemented according to NRC regulations, and with an α-tocopherol (mg) to PUFA (g) ratio of 0.49:1, had low α-tocopherol levels in their tissues. Depending on the quantity of iron administered, the piglets showed signs of vitamin E deficiency which ranged from acute, with high mortality, to mild, with only microscopic evidence of hepatocyte dissociation. Piglets raised on a soybean oil based milk replacer diet, supplemented with the same amount of α-tocopherol, and with a ratio of α-tocopherol to PUFA of 0.21:1, showed no signs of vitamin E deficiency and had significantly higher tissue levels of vitamin E than the piglets raised with the canola oil milk replacer. The factor(s) present in canola oil which increased the demand for vitamin E are unknown.

Ultrastructural Study of Ni3S2-Induced Tumors in Rats

An ultrastructural study was conducted on a total of 24 tumors selected from 70 tumors Induced by intramuscular injection of Ni3S2 in Fischer and Hooded rats. Well differentiated rhabdomyosarcomas were predominantly composed of strap‐like cells containing numerous myofilaments occasionally forming S‐line‐like structures, whereas poorly differentiated rhabdomyosarcomas were made up mainly of round or oval cells with abundant cytoplasm. Embryonal rhabdomyosarcomas contained cells resembling the mast cells in myxomatous areas as well as spindle‐shaped myoblast‐like cells. Mesenchymal tumors exhibited morphological characteristics of the lymphoid cells. The tumor cells from leiomyosarcoma‐like tumors showed myoblast‐like appearance. Tumors diagnosed as fibrosarcoma‐like tumors at the light microscopic level demonstrated the ultrastructural characteristics of fibrosarcomas. The possibility of a multicentric origin of the tumor cells in Ni3S2‐induced tumors has been discussed.

Platelet alterations in porcine stress syndrome

Platelets in blood collected from pigs identified as normal (21) or stress susceptible (25) on the basis of their response to halothane challenge, were subjected to electron microscopic examination in order to test whether the ultrastructural features of stress susceptible pigs exhibit any deviation from those of normal. The most striking feature of the platelets from stress susceptible pigs was the extent of dilatation of the open canalicular system (OCS). The difference in platelet morphology between normal and stress susceptible pigs was consistent regardless of the anticoagulants used for blood collection indicating that the platelet alteration may be an inherent component of the porcine stress syndrome.

Erratum to: Liver morphometrics and metabolic blood profile across divergent phenotypes for feed efficiency in the bovine

© The Author(s) 2017. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Erratum to: Acta Vet Scand (2017) 59:24 DOI 10.1186/s13028‐017‐0292‐1 After publication of the original article [1] it was brought to our attention that author Brenda Lynn Coomber was incorrectly included as Brenda Lee Coomber. The correct spelling of the name is included in the author list of this erratum and updated in the original article.

Chromosomes of chicken-pheasant hybrids

a majority of the embryos carry a haploid set each of chicken and pheasant chromosomes. Three of the male embryos resulting from chicken female-pheasant male crosses were cytogenetically indistinguishable from male domestic chicken whereas two embryos obtained from a similar cross, were chimeras composed of chicken cells and hybrid cells. The presence of hybrid embryos of chicken karyotype is attributable either to parthenogenesis in the hens or to fertilization of the hens ovum by rooster spermatozoa from previous matings, surviving in the female reproductive tract. It is postulated that the chimeric hybrids may be the result of double fertilization of the ovum and its retained polar body, and that the spermatozoa from the semen invested during this investigation and the rooster spermatozoa remaining viable in the hens oviduct from previous matings, were probably involved in this process.

Inhibitory effect of phenyl N-terf-butyl nitrone on Kupffer cell phagocytosis.

Light microscopy studies of rat liver were conducted after injection of India ink. The data indicated that Kupffer cell phagocytosis was inhibited by C-phenyi-N-tert-butyl nitrone (PBN), as well as by the Kupffer cell antagonist gadolinium chloride.