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Biomedical subjects

K Takehana

Publications and source records attributed to K Takehana.

86 records · Page 5Linked to original sources

Carbohydrate histochemistry of bovine duodenal glands.

The complex carbohydrates in the bovine duodenal glands were examined histochemically using 5 peroxidase-labeled lectins to achieve a better knowledge of their glycoprotein profiles. The presence of at least 2 different cell types and secretion of neutral mucin were observed in the bovine duodenal glands. The duodenal gland cells located in the central area of the lobules contained neutral glycoproteins with different saccharide residues as beta-D-gal-(1-3)-D-galNAc, alpha-D-galNAc, beta-(1-4)-D-glcNAc, NeuNAc and D-galNAc. The other cell types located in the peripheral area of the lobules contained alpha-L-Fuc, alpha-D-galNAc, beta-(1-4)-D-glcNAc, NeuNAc and D-galNAc. These findings seemed to be characteristic of a unique digestive process of the ruminant.

Animals↗

Anomalous caudal vena cava passing through the vertebral canal in a calf.

A 15-day-old female Holstein-Friesian calf with an anomalous caudal vena cava was examined macroscopically, roentgenologically, and histologically. The calf, weighing 43 kg, had severe scoliosis. A common renal vein merged into a single venous trunk formed by the union of the left and right common iliac veins. The trunk entered the vertebral canal through the left intervertebral foramen formed by the last (13th) thoracic and the first lumbar vertebrae. The trunk continued along the ventral side of the narrowing spinal cord inside the canal, and then ran out the left intervertebral foramen formed by the 8th and 9th thoracic vertebrae and emptied via the right azygos vein into the cranial vena cava. In contrast, the hepatic vein passed through the foramen vena cava independently of the trunk and entered the right atrium directly. The pathogenesis of the present anomaly may be explained as follows: The right subcardinal vein, failing to make connection with the liver, shunted directly into the right azygos vein derived from the right supracardinal vein. The body axis began to curve before ossification of the vertebrae occurred. Consequently, the developing right supracardinal vein, located close to the spinal cord, is thought to have become enclosed in the vertebrae with the spinal cord during the early fetal stages.

Animals↗

Seven-legged calf--dipygus with an extra foreleg at the pelvic region.

A male Holstein-Friesian calf with seven legs was examined macroscopically and radiographically. External features included two normal forelimbs, two normal hindlimbs (lateral hindlimbs), and two abnormal hindlimbs (medial hindlimbs) which were underdeveloped. Also, a rudimentary forelimb, which was attached to the pelvic region, was observed between both the medial hindlimbs. It consisted of an underdeveloped humerus, a duplicated ulna, several carpal bones, a partially duplicated metacarpal bone and three digits with three hoofs. This leg was connected with two sets of coxae by a irregular-shaped bone considered the vestigial vertebrae and ribs. Two penises and scrotums, three kidneys and testes were also observed. This calf is the first case of dipygus associated with pygopagus parasiticus in cattle. Based on these findings, the pathogenesis of this rare anomaly was briefly discussed from an embryological point of view.

Abnormalities, Multiple↗

Scanning electron microscopic studies on the red pulp of the mink spleen.

In order to obtain three-dimensional information on the fine architecture of the red pulp of the mink spleen, especially the circulation pattern in the red pulp, perfusion-fixed and freeze-cracked specimens were examined with a scanning electron microscope. A latticework was formed by elongated endothelial cells (rod cells) with side processes and the spongy reticular tissue. The outer surface of the sinus was covered with fine processes of reticular cells. Numerous sheathed arteries were found in the splenic cord. The sheath was composed of a few layers of flat reticular cells. The arterial capillaries of the red pulp opened directly into the cordal space. No evidence could be detected to prove or suggest any direct continuity between arterial capillaries and splenic sinuses. These results strongly support the concept of "open circulation", at least in the red pulp of the mink spleen, with the possibility of a "functionally closed circulation" under some physiological conditions.

Animals↗

Histochemistry of complex carbohydrates in the horse duodenal gland.

Complex carbohydrates were examined in glandular cells of the horse duodenal gland by using lectin histochemical techniques. In the horse, the duodenal gland was distributed in the area from the uppermost part of the small intestine to a point about 6m caudal to the pylorus. It consisted of two types of cells, mucous and serous cells. The former was found in glands distributed almost all over this part, but the latter was present in glands distributed restrictedly to the uppermost part of the small intestine at a point about 10 cm caudal to the pylorus. The cytoplasm of the mucous cell contained neutral glycoproteins with different saccharide residues as alpha-D-mannose, N-acetyl-beta (1----4)-D-glucosamine, galactose, alpha-galactose, alpha-N-acetylglucosamine, beta-D-Gal (1----3)-D-GalNAc, alpha-L-fucose and sialic acid. On the other hand, the serous cell contained neutral and acid glycoproteins with different residues such as alpha-D-mannose, alpha-D-glucose, beta-D-galactose(1----3)-D-N-acetylgalactose, alpha-L-fucose, N-acetyl-alpha-D-galactosamine, N-acetyl-beta (1----4)-D-glucosamine, galactose, alpha-galactose, alpha-N-acetylglucosamine and sialic acid. It is also elucidated in the present study that lipase, an enzyme for digestion, is contained in the serous cell of the equine duodenal gland.

Animals↗

Small-square (SS) net exists in trout muscle.

The small-square-net form (with the large-square-net form) was clearly observed in brown trout muscle in cross-square-net-section. Fresh adductor mandibularis and dorsal muscle strips, isometrically clamped to prevent contraction, were prefixed in 3% glutaraldehyde, 0.1 M cacodylate, pH 7.4, and post-fixed in 1% osmium tetroxide in veronal acetate buffer at 2 degrees C. The samples were dehydrated, embedded in epon-araldite, cross-sectioned, and stained with uranyl acetate and lead citrate for electron microscopic observation. The sections provided the first clear evidence of the small-square-net form, coexisting with the basket-weave pattern, in fish muscle. In previous experiments, we could not demonstrate the small-square-net pattern convincingly with guppy tissue (Yamaguchi et al., 1985a) which may be more susceptible to chemical or physical stress than is trout tissue. The existence of the diverse structural patterns in cross-sections of some, if not all, vertebrate striated muscle must be derived from a basic unit which although it may vary in size among species is structurally identical. The findings agreed with our unified model of narrow and wide Z-line structure (Yamaguchi et al., 1980; Yamaguchi et al., 1985a; Yamaguchi et al., 1985b).

Animals↗

[A possible circadian rhythm of susceptibility to thiamylal].

A circadian rhythm of the susceptibility to thiamylal was evaluated in 30 patients. They were divided into two groups; 15 patients were induced around 9 AM (Morning-group) and the rest were in the early afternoon (Afternoon-group). The induction was performed by intravenous administration of thiamylal sodium. Parameters measured were the time and doses of thiamylal sodium to obtain the loss of consciousness and the loss of eyelash reflex. The results were as follows; the doses of thiamylal sodium to obtain the loss of consciousness were 3.5 +/- 0.6 mg.kg-1 (mean +/- SD) in Morning-group, and 4.1 +/- 0.4 mg.kg-1 in Afternoon-group, respectively. Thus, larger doses of thiamylal were necessary to obtain the loss of consciousness in Afternoon-group than in Morning-group (P less than 0.01). The doses of thiamylal sodium to obtain the loss of eyelash reflex were 4.4 +/- 0.8 mg.kg-1 in Morning-group and 5.0 +/- 0.6 mg.kg-1 in Afternoon-group, respectively. Also, larger doses of thiamylal were necessary to obtain the loss of eyelash reflex in Afternoon-group than in Morning-group (P less than 0.05). This study suggests that a circadian rhythm of the susceptibility to thiamylal exists in humans.

Adult↗

Molecular cloning and characterization of cellular genes whose expression is repressed by the adenovirus E1a gene products and growth factors in quiescent rat cells.

Several cDNA clones of cellular genes, whose expression is repressed by the adenovirus type-12 E1a gene products, were isolated from a rat 3Y1 cell cDNA library by differential plaque hybridization with labeled cDNA probes prepared from 3Y1 and the derivative cell line expressing the E1a gene constitutively. The changes in the levels of these gene transcripts during cell-cycle progression from G0 to G1 to S phase were analyzed with 3Y1 cells and gMA cell lines, derived from 3Y1 cells, in which the expression of the E1a gene or its 13S, 12S cDNA can be switched on by the addition of dexamethasone. Quantitation of the transcripts by Northern-blot hybridizations and by nuclear run-on experiments revealed the following. (i) The level of clone-53 mRNA (which turned out to be the fibronectin (FN)-coding mRNA) is very high in resting gMA cells and decreased rapidly after switching on of the E1a gene or its 13S, or 12S cDNA. (ii) The addition of serum or platelet-derived growth factor to resting 3Y1 cells also resulted in a rapid decrease in the FN mRNA level, but the addition of epidermal growth factor (EGF) had little or no effect. (iii) The level of clone-56 mRNA in gMA cells was not affected by the induction of the E1a gene expression; however, the addition of EGF to resting gMA or 3Y1 cells resulted in a decrease of this mRNA after a 12- to 16-h lag period. Induction of the E1a gene expression in gMA cells treated with EGF shortened the lag period. The addition of serum to resting 3Y1 cells decreased the clone-56 mRNA level without a significant lag period.

Adenoviridae↗

Effect of beta-aminopropionitrile and hyaluronic acid on repair of collagenase-induced injury of the rabbit Achilles tendon.

Collagenase was injected into the Achilles tendon of both hind legs of 10 clinically normal adult male New Zealand white rabbits. One month after induction of the injury, beta-aminoproprionitrile (BAPN) or hyaluronic acid (HA) was injected into the tendon core of the right hind leg of each rabbit, the left hind leg being left untreated. The treatment effects were evaluated by electron microscopy and analysis of the glycosaminoglycan (GAG) content of samples at 2 and 6 months post-treatment. At 2 months, collagen fibrils in tendons from both hind legs were relatively small in diameter, irregularly arranged, and interspersed with abundant active tenocytes as compared with those in normal tendon uninjured by collagenase. In the matrix, the amount of HA increased, but chondroitin-6-sulphate was eliminated. At 6 months, BAPN-treated tendons had small-diameter, regularly arranged collagen fibrils. HA-treated tendons, on the other hand, had large diameters, as well as regularly arranged collagen fibrils by comparison with non-treated tendon. The results suggest that HA, unlike BAPN, promoted healing.

Achilles Tendon↗

Tc-99m sestamibi defect magnitude predicts the amount of viable myocardium after coronary reperfusion despite the presence of severe residual stenosis.

BACKGROUND: Whether technetium-99m-labeled methoxyisobutyl isonitrile (Tc-99m sestamibi) imaging early after reperfusion can detect the amount of salvaged viable myocardium in the presence of a severe residual stenosis remains controversial. METHODS AND RESULTS: Nine dogs underwent total left anterior descending coronary artery (LAD) occlusion for 40 to 180 minutes followed by reperfusion through a flow-limiting stenosis. They were divided into 2 groups based on infarct size (group 1, <15% of risk area; group 2, > or =15%). Triphenyl tetrazolium chloride infarct size was measured by planimetry, and regional flow was quantified by radiolabeled microspheres. Mean infarct size was 9.3% +/- 3.0% of risk area in group 1 versus 51.1% +/- 4.8% in group 2 (P <.01). Tc-99m sestamibi was injected 30 minutes after reperfusion, when the LAD flows were comparable for group 1 (9 +/- 2 mL. min(-1)) and group 2 (9 +/- 1 mL. min(-1)). Left circumflex coronary artery flows were 33 +/- 5 and 32 +/- 9 mL. min(-1) for groups 1 and 2, respectively. Despite administration of Tc-99m sestamibi during diminished residual LAD flow after reperfusion, defect magnitude on ex vivo images in group 1 was significantly less severe than that in group 2, which had larger infarcts (0.71 +/- 0.02 vs 0.42 +/- 0.05, P <.01). This reflects greater salvage and more viability in group 1. CONCLUSION: Resting perfusion imaging with Tc-99m sestamibi accurately determined viability of the infarct zone despite reperfusion through a residual stenosis. Tc-99m sestamibi imaging may prove useful in the clinical setting for the prediction of the amount of salvaged myocardium.

Animals↗

Gene defect of dermatan sulfate proteoglycan of cattle affected with a variant form of Ehlers-Danlos syndrome.

A defect of the core protein of dermatan sulfate proteoglycan was suspected in a Holstein calf affected with a variant form of Ehlers-Danlos syndrome. The mutation was a guanine-to-adenine transition at nucleotide position 254, which resulted in a serine-to-asparagine substitution of the bovine proteoglycan core protein. This substitution occurred in the serine-glycine dipeptide repeat that was suspected to be the binding portion of dermatan sulfate. This point mutation in the genome was also detected by the use of restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) methods. The results of the RFLP and PCR indicated that the calf was a heterozygote of an abnormal gene and a normal gene of the core protein. The interpretation of these data revealed that the functional abnormality in cutaneous tissues of the calf was caused by an abnormal gene of the proteoglycan core protein, which induced a substitution of amino acid.

Amino Acid Sequence↗

Immunolocalization of cyclins D and E and cyclin dependent kinase (cdk) 2 and 4 in human breast carcinoma.

We studied the immunolocalization of cyclins D1 and E and their corresponding partner cyclin dependent kinases (cdk), cdk4 and cdk2 in 41 cases of human breast malignancy (21 invasive ductal carcinomas and 19 invasive lobular carcinomas) and examined the correlation of the labeling indexes among these cyclins, cdks, Ki67, estrogen receptor (ER) and progesterone receptor (PR). Cyclin D1 immunoreactivity was observed exclusively in the nuclei of tumor cells in 27/41 (65%) of the cases examined. Immunoreactivity for cyclin E and cdk2 was detected in all the cases and observed in the nuclei of both carcinoma and non-carcinoma cells. cdk4 immunoreactivity was detected in 39/41 (95%) cases and found in carcinoma and non-carcinoma cells. In all carcinomas examined, a significant correlation was observed only between Ki67 and cyclin D1 (p = 0.0037). However, when examining only invasive ductal carcinomas, a significant correlation was detected between Ki67 and cyclin D1 (p = 0.0069), Ki67 and cdk2 (p = 0.0043) and cyclin D1 and cdk4 (P = 0.0024). Only cyclin D1 correlated with the pathologic stages of the disease and histological grades of invasive ductal carcinoma. Among these cyclins and cdk, overexpression of cyclin D1 is considered to play an important role in the development of human breast malignancy through abnormal proliferation. No significant correlation was observed between steroid receptor status and any of cyclins and cdks examined. Cyclin D1 and cdk2 expression correlated with cell proliferation (Ki67) and cyclin D1 expression with expression of cdk4 in invasive ductal carcinoma but not invasive lobular carcinoma. Cyclin E expression did not correlate with cell proliferation, cyclin D1 or cdks possibly due to deregulation of its expression. These results also indicate different patterns of cyclin D1, cyclin E, cdk2 and cdk4 expression between invasive ductal and lobular carcinoma of human breast.

Breast Neoplasms↗