Immunohistochemical characterization of canine neuroepithelial tumors.

The expression of cell differentiation and proliferation markers of canine neuroepithelial tumors was examined immunohistochemically to identify the histogenesis of these tumors. Astrocytomas (n = 4) consisted of cells positive for glial fibrillary acidic protein (GFAP) and nestin and a few cells positive for doublecortin (DCX). Immunoreactive cells for receptor tyrosine kinases (epidermal growth factor receptor and c-erbB2) and their downstream molecules (phospho-extracellular signal-regulated kinase 1/2 and phospho-Akt) were often detected in astrocytomas, especially in medium- and high-grade tumors. Gliomatosis cerebri (n = 3) consisted of cells positive for ionized calcium-binding adaptor molecule 1 and GFAP, including a minor population of cells positive for nestin, DCX, and beta III tubulin, suggesting their glial differentiation. In choroid plexus tumors (n = 4), most tumor cells were positive for cytokeratins AE1/AE3 and 18, and few were positive for GFAP. The majority of cells of oligodendrogliomas (n = 5) were DCX positive, but the tumors also contained minor populations of cells positive for GFAP, nestin, or beta III tubulin. Primitive neuroectodermal tumors (PNETs; n = 2) consisted of heterogeneous cell populations, and the tumor cells were positive for nestin, beta III tubulin, and DCX, suggesting glial and neuronal differentiation. The major population of neuroblastoma cells (n = 3) were positive for beta III tubulin and DCX, suggesting single neuronal differentiation. As for antiapoptotic cell death molecules, most tumor cells in the choroid plexus tumors, PNETs, and neuroblastomas were intensely positive for Bcl-2 and Bcl-xL, whereas those in gliomatosis cerebri were almost negative. In astrocytomas, Bcl-xL-positive cells predominated over Bcl-2-positive cells, but the opposite was observed in oligodendrogliomas. The immunohistochemical results were analyzed by hierarchical clustering, and the constructed dendrogram clearly indicated a novel position of oligodendrogliomas: the primitive glial and neuronal differentiation.

Complementary distributions of amyloid-beta and neprilysin in the brains of dogs and cats.

Neprilysin is an amyloid-beta-degrading enzyme localized in the brain parenchyma. The involvement of neprilysin in the pathogenesis of Alzheimer's disease has recently received much attention. We examined the localization of neprilysin and amyloid-beta, as well as the activity of neprilysin, in the brains of dogs and cats of various ages to clarify the relationship between neprilysin activity and amyloid-beta deposition. The distribution of neprilysin was almost identical in dogs and cats, being high in the striatum, globus pallidus, and substantia nigra, but very low in the cerebral cortex. The white matter and hippocampus were negative. Neprilysin activity in the brain regions in dogs and cats was ranked from high to low as follows: thalamus/striatum > cerebral cortex > hippocampus > white matter. Amyloid-beta deposition was first detected at 7 and 10 years of age in dogs and cats, respectively, and both the quantity and frequency of deposition increased with age. In both species, amyloid-beta deposition appeared in the cerebral cortex and the hippocampus. In summary, the localization of neprilysin and neprilysin activity, and that of amyloid-beta, were complementary in the brains of dogs and cats.

Fractal analysis of senile plaque observed in various animal species.

In the present study, the fractal dimension (FD), a concept to determine morphological complexity, was applied to morphological estimation of animal and human senile plaque using a computer-aided method. The FDs of mature plaque in a 17-year-old dog were significantly higher than those of diffuse plaque in 11- to 16-year-old dogs. In both types of plaque, the FD tended to increase as the size expanded and there was a significant difference between the slope values of the approximate line for diffuse and mature plaque. In humans, there was also a significant difference in FD value between diffuse and mature plaque. No significant differences were observed between the two types of plaque in a bear or a cynomolgus monkey. The FD of feline diffuse plaque was significantly lower than that of a camel, bear and monkey. These results indicated that the diffuse and mature plaque of the dog might form in a different manner, and similar events may occur in human senile plaque formation. In addition, specific shapes and different FD values of the diffuse plaque among animals suggested that the original conditions for plaque formation would be different.

[Evaluation of the entrance examination for baccalaureate nursing program].

The purpose of this study was to examine the relationship among the variables of the entrance examination for baccalaureate nursing program, records from senior high school, and records of the courses during nursing program. The variables of the entrance examination were the scores obtained by subjects on their entrance examination which included Japanese, English, Chemistry, short essay examination, and interview. Senior high school records included grade-point-average, Japanese, Social Studies, Mathematics, Science, Health Science, Arts, English and Home Economics. The variables of records during nursing program were achievement scores of the essential courses which taken by all subjects. The data were attained from records of 551 baccalaureate program graduates (graduates from 1982 to 1991, 61 students with recommendation entrance included) from one of the urban colleges of nursing in Japan. Peason product moment correlations and stepwise multiple regression analyses were used to identify the relationship between variables. As results, there were no relationship between entrance examination records and senior high school records except English (r = .47, p < .001). There was moderate relationship between entrance examination English and English during nursing program. Between senior high school record and nursing program records, there was a weak relationship between English & Foreign languages, Health Sciences & Physical Exercise, Science & Natural Science. Among those courses during nursing education, there was a tendency for English scores correlated significantly high with another courses than any other subjects. These findings indicate that educators could identify students early in their college education who would have difficulty in nursing courses and assist them in their learning.

Ages at peak velocity and peak velocities for seven body dimensions in Japanese children.

Seven body dimensions of 37 Japanese children, 16 boys and 21 girls, were measured longitudinally at 6-monthly intervals from 9 through 15 years of age. Spline curves were fitted to the longitudinal data of each dimension to obtain age at peak velocity and magnitude of peak velocity for each child. Ages at peak velocity for each dimension occurred, on average, later in boys than in girls. Mean peak velocities were also larger in boys except for chest circumference. Ages at peak velocity occurred, on average, earlier in Japanese than in European and North American children.

[The secular trend of standing height in adolescent girls from longitudinal data].

In this study which is based on the longitudinal data aggregated from health examination records, the subjects consist of 287 girls who attended a private school in Tokyo. The subjects are divided into five groups according to birth year from 1950 to 1970 in order to find secular trend during twenty years with one-way analysis of variance. Age at Peak Height Velocity (APHV), Peak Height Velocity (PHV) and Height attained at Peak Height Velocity (HPHV) were computed in each height velocity curve derived from differential calculus of height distance curve. The result show that HPHV is gradually getting taller by year although APHV and PHV do not change. It may be considered that our subjects of the private school are girls of families in the relatively upper-middle class.