Search PubMed⌕ Search

Biomedical subjects

J Yamada

Publications and source records attributed to J Yamada.

At least 451 records · Page 25Linked to original sources
PubMed1983

Effects of omega-aminosulfonic acids on lipid metabolism in dietary hyperlipidemic rats.

The effects of 2-aminoethanesulfonic acid (taurine) and its structural analogs, 3-aminopropanesulfonic acid (homotaurine) and 4-aminobutanesulfonic acid (ABSA), on lipid metabolism were investigated in rats with dietary hyperlipidemia. The serum cholesterol levels increased approximately five-fold in rats fed a diet containing 0.5% cholesterol and 1% cholic acid for 10 d. omega-Aminosulfonic acids dissolved in water were orally administered for 10 d concurrently with the 0.5% cholesterol diet. Taurine suppressed elevation in serum cholesterol levels by 46.9 and 63.9% at doses of 250 and 500 mg/kg, respectively. Serum triglycerides levels, however, were not significantly altered by taurine. Both homotaurine and ABSA, 500 mg/kg each, inhibited the elevation in serum cholesterol levels to an extent, namely, 32.0 and 22.3% lower than that of the controls, respectively. Treatment with homotaurine in doses of 250 and 500 mg/kg significantly increased serum triglycerides levels by 37.6 and 35.9%, respectively, and ABSA (500 mg/kg) also revealed a tendency to raise these levels. All the sulfonic acids (500n mg/kg each) reduced cholesterol levels in the liver similarly, while changes in triglycerides levels in the liver were insignificant. Both taurine and homotaurine (t00 mg/kg each) inhibited intestinal absorption of cholesterol. The inhibitory effect of homotaurine was as great as 31.5% and greater than that of taurine. No influence of taurine (500 mg/kg) was observed in lipoprotein lipase activity in the epididymal fat tissue, but the activity did appear to be inhibited by homotaurine (500 mg/kg).

Adipose Tissue↗
PubMed1983

Polymorphism in Pg-1 (urinary pepsinogen-1) locus in the rat and its linkage analysis.

Cramer (1981) reported that Pg-1 (urinary pepsinogen) in the rat was loosely linked with albinism in the linkage group I. We performed a three point test on the loci of pg-1, c, and Hbb. We could reconfirm that pg-1 was autosomal trait with two co-dominant alleles of pg-1a and pg-1b. But in progeny of ((WF X IS) X WF) backcross, pg-1 was linked to neither c nor Hbb, while a close linkage between c and Hbb was detected. Also pg-1 was not linked to Mup-1 (LG II), a (LG IV), Es-3 (LG V), and h (LG VI). pg-1 will be one of the most valuable genetic markers of the rats, since pg-1 was highly polymorphic among inbred strains of rats, and not linked to LG I, II, IV, V, and VI.

Animals↗
PubMed1983

A light microscopic study of the gastro-entero-pancreatic endocrine cells of the mink (Mustela vison).

Endocrine cells in the stomach, intestine and pancreas of the mink were investigated, using silver impregnation and immunohistochemical methods, and the following results were obtained. The stomach of the mink possesses a well-developed acid-secreting region which occupies about 70% of the gastric mucosa. Half of Brunner's glands whose excretory duct empties in the most proximal duodenum are located in the duodenal submucosa with the remainder in the pyloric submucosa. The area covered by the glands is 7.5 mm long in rostrocaudal direction. Endocrine cells are numerous in Brunner's glands, in the pyloric gland region and in the duodenum, while they are few in the colorectum. Somatostatin-immunoreactive cells are distributed throughout the whole GEP system, while gastrin-immunoreactive cells are located mainly in the pyloric gland region. Secretin-, motilin- and neurotensin-immunoreactive cells are found in the duodenum, jejunoileum and lower jejunoileum, respectively. Glucagon-immunoreactive cells are located mainly in the pancreatic islet and are distributed scarcely in the fundic gland region. A few glucagon-immunoreactive cells are also found in the middle portion of the jejunoileum. In addition to the somatostatin-immunoreactive cells, argentaffin, glucagon- and glicentin-immunoreactive cells in the fundic gland region and argentaffin and gastrin-immunoreactive cells in the pyloric gland region extend cytoplasmic processes along the basement membrane. This suggests a paracrine secretion of these cell types. A few open type cells which are stained with Hellerström-Hellman's or Sevier-Munger's method or are reactive to the somatostatin antiserum are found in the fundic gland region. A possible relation between the present observation of the endocrine cells and the eating habits of the mink is discussed.

Animals↗
PubMed1983

An immunohistochemical and ultrastructural study of Segi's cap, a large aggregation of gut endocrine cells, in bovine fetuses.

Segi's cap, a large aggregation of basal-granulated cells at the top of the intestinal villus, was studied in the proximal small intestine of bovine fetuses by histological, immunohistochemical and ultrastructural techniques. 1) Typical Segi's caps were seen in the duodenum and proximal jejunum in bovine fetuses. 2) Smaller groups of basal-granulated cells were found in the villous and partly also in the cryptal epithelium, as well as in the subepithelial lamina propria. The possible mechanism for their occurrence was discussed in connection with the fate of the cap. 3) Segi's caps were present in a neonatal calf before the suckling stage, but not in 3 or 4 week-old calves. The process of and reason for this abrupt disappearance of the caps are unknown. 4) The Segi's cap in bovine fetuses consisted mainly of argyrophil cells as demonstrated by Grimelius' and Hellerström-Hellman's silver methods. Only a few argentaffin cells were found in fetal caps using a modified Masson-Hamperl's silver method. 5) Immunohistochemically, somatostatin-, gastrin-, motilin- and secretin-immunoreactive cells were identified. 6) Four different endocrine cell types could be distinguished in the bovine Segi's cap on the basis of the ultrastructural appearance of their secretory granules.

Animals↗
PubMed1983

Progression of congenital kyphosis in Ishibashi rats.

The development of congenital kyphosis was studied radiographically and histologically in 32 female and 34 male Ishibashi rats between the fourth and thirty-sixth week after birth. The major congenital spinal anomalies were defects of segmentation in the lumbar area. The malformation was classified into four groups according to the state of non-segmentation seen in radiographs. The progression of kyphosis was closely related to various changes at intervertebral spaces. The spinal deformity resulting from narrowing of the intervertebral spaces without bony fusion did not progress with growth, and the epiphyseal plates remained relatively intact unrelated to the existence of disc tissue. The deformity resulting from ventral bony fusion without radiographic bony anomalies showed histologically dysplastic epiphyseal plates on the ventral side. Progression of the kyphosis occurred in this type of deformity. The kyphosis resulting from bony fusion and ventral wedge-vertebrae progressed in the males. Progressive kyphosis appeared to be due to a difference in growth potential between the ventral and dorsal epiphyseal plates.

Animals↗
PubMed1982

Vasoactive intestinal polypeptide (VIP) immunoreactivity of endocrine-like cells in the feline pyloric mucosa.

Immunoreactivity to VIP by endocrine-like cells in the feline pyloric mucosa was examined by using three kinds of region-specific anti-porcine VIP sera. VIP-immunoreactive endocrine-like cells were detected clearly with all of the VIP antisera used. They were located mainly around the neck of the pyloric glands. Some of these endocrine-like cells showed dilution-dependent immunoreactivity against VIP antisera. The immunostaining intensity of VIP-immunoreactive endocrine-like cells showing dilution-independence could not be distinguished from those of nerve elements. The present results suggest that the immunoreactivity with properties very similar to those of authentic VIP may be present in the endocrine-like cells of the feline pyloric glands.

Animals↗
PubMed1982

Genetical studies of low plasma alkaline phosphatase (ALP) activity in the IS strain of rats.

The low plasma alkaline phosphatase (ALP) activity of the IS strain of rats was genetically analyzed by using the cross matings with the BN strain. In the F1 hybrids, the ALP activities were intermediate but largely biased to the low activity. In the (F1 x BN) back-cross progeny, the distributions of plasma ALP activities were apparently bimodal in both sexes. Alp-2 locus with two alleles of Alp-2h and Alp-2l is tentatively proposed. Alp-2 locus did not link to the rat linkage group (LG) I, II, IV, V, and LGs containing Amy-1 and Cs-1. In the (F1 x IS) back-cross progeny, the plasma ALP activities were not different from that of the F1 hybrids and the distribution was not bimodal. Alp-2l may be dominant over Alp-2h. One third of the back-cross progeny showed vertebral anomalies and the difference of plasma ALP activities was not detected between the rats with and without vertebral anomalies.

Alkaline Phosphatase↗
PubMed1981

Intranuclear filamentous inclusions in the gastro-entero-pancreatic (GEP) endocrine cells of birds.

Intranuclear filamentous inclusions were found in the normal endocrine cells of the avian stomach and pancreas. These inclusions were composed of a bundle of closely packed filaments (6-8 nm in diameter), being ultrastructurally similar to those found in the nucleus of various neurons. Most of them appeared as single rod- or spindle-shaped bodies; aggregations of two or more inclusions were rarely seen within a single nucleus. Cells with an intranuclear inclusion often contained a cytoplasmic fibrillar bundle similar to the intranuclear inclusion.

Animals↗