Naturwissenschaften
September 2022
Many small pelagic fishes obligately form schools; some of these schools reach remarkable sizes. Although the school is a fundamental and important ecological unit and is the site of biological interactions such as competition and predation, information on schooling processes in the field remains scarce. Here, we examined the quantitative relationships between population density and school size, the number of schools, and other school characteristics (i.
View Article and Find Full Text PDFWe investigated chronological changes in immunohistochemical phenotyping in the thymus and spleen in Crl:CD rats up to the age of about one year. In the thymus, T cells increased markedly from 3 to 4 weeks of age. Proliferating cells also increased markedly at these points.
View Article and Find Full Text PDFPorencephaly was observed in a female cynomolgus monkey (Macaca fascicularis) aged 5 years and 7 months. The cerebral hemisphere exhibited diffuse brownish excavation with partial defects of the full thickness of the hemispheric wall, and it constituted open channels between the lateral ventricular system and arachnoid space. In addition, the bilateral occipital lobe was slightly atrophied.
View Article and Find Full Text PDFSevere bilateral cataract was found in a 7 year-old naïve female cynomolgus monkey (Macaca fascicularis) 3 months before necropsy. During macroscopic examination, severe opacity and thinning of the lens were observed in both eyes. Histopathology revealed that the lens nuclei and majority of cortex lens fibers had disappeared and become excavated, while the lens fibers in the subcapsular area were swollen and distorted.
View Article and Find Full Text PDFTwo cases of spontaneous focal hepatic hyperplasia were observed in young female cynomolgus macaques (Macaca fascicularis). Grossly, a single raised nodule was observed in the left hepatic lobe. Histopathologically, the nodule compressed surrounding normal tissue; however, the hepatic cords within the nodule continued to those in the nor mal area except in part.
View Article and Find Full Text PDFTo clarify the morphological characteristics of the cynomolgus monkey immune system, we analyzed quantitative data on their lymphoid organs. Spleens, major lymph nodes and Peyer's patches were sampled from cynomolgus monkeys, and the lymphoid follicle and germinal center areas and percentages of CD3- and CD20-positive areas were calculated. All the organs analyzed showed large interindividual variations in the sizes of lymphoid follicles and germinal centers.
View Article and Find Full Text PDFTo elucidate the effect of a large dose of di (2-ethylhexyl) phthalate (DEHP), a plasticizer and peroxisome proliferator-activated receptor-α (PPARα) agonist, on hepatic peroxisomes, we orally administered 1,000 mg/kg/day, once daily, to 3 male and 4 female cynomolgus monkeys for 28 days consecutively. Light-microscopic and electron microscopic examinations of the liver were carried out in conjunction with measurement of the hepatic fatty acid β-oxidation system (FAOS), carnitine acetyltransferase (CAT) and carnitine palmitoyltransferase (CPT) activities, which are peroxisomal and/or mitochondrial enzyme activities. Electron microscopically, enlargement of the mitochondria was observed with lamellar orientation of the cristae along the major axis.
View Article and Find Full Text PDFIn a seven-year-old male cynomolgus monkey, erythema of the upper eyelid and forehead and corneal opacity, edema and conical protrusion in the eye were observed. At necropsy, ophthalmological and serological examinations revealed binocular corneal opacity and conical protrusion and a high IgE level, respectively. Thinning of the epithelium and stroma of the cornea were noted histopathologically.
View Article and Find Full Text PDFCS-1008, a humanized monoclonal antibody that is agonistic to human death receptor 5, was intravenously administered to cynomolgus monkeys twice a week for 13 weeks at 3 different dose levels (5, 15 and 42 mg/kg) in order to evaluate its potential toxicity. A control group received phosphate buffered saline containing 0.01% polysorbate 80.
View Article and Find Full Text PDFAlzheimer's disease (AD) in humans is a progressive neurogenic disease that can be linked with such characteristic pathological findings in the cerebrum as senile plaques (SPs), neurofibrillary tangles (NFTs), cerebral amyloid angiopathy (CAA), and neuronal loss. In the present study, the authors investigated the age-related morphological changes in 12 middle-aged and 12 young cynomolgus monkeys. Low numbers of neurons and astrocytes in the hippocampal region in cynomolgus monkeys accompanied ageing, and there was a high number of microglial cells; however, no clearly neurotoxic abnormalities due to beta-amyloid were noted before the age of 20 years.
View Article and Find Full Text PDFA solid mass arising from the mammary gland was found in a 7-year-old female cynomolgus monkey. Histologically, the mass consisted of 2 components: spindle-shaped or ovoid sarcomatous cells and squamous epithelial cells. Metastatic nodules noted in the lung, liver and the gallbladder had the same histological features as the mammary mass.
View Article and Find Full Text PDFThe expression and localization of glial cell line-derived neurotrophic factor (GDNF) and its receptor GFR alpha1 in the testis were examined, because the blood-testis barrier is a well-known tissue barrier and we previously reported that GDNF reduced the endothelial permeability of the blood-brain barrier (BBB). Five minutes after intravenous injection of Evans blue (molecular weight, 960.6) or fluorescent dextran (molecular weight 10000 and 70000), Evans blue was observed outside microvessels of the testis, whereas the fluorescent dextran was not.
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