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Biomedical subjects

Y Takada

Publications and source records attributed to Y Takada.

At least 505 records · Page 28Linked to original sources
PubMed1990

Fluid-path in the mandible and maxilla.

We examined fluid-paths in the maxilla and mandible of the dog, and compared them with Kihara's extravascular fluid-path-system. Areolar tissue is formed in the walls of the Volkmann's and Haversian canals. This tissue is composed of collagenous and reticular fibers. Kihara confirmed the collagenous fibers were encircled, however we could not ascertain whether they were encircled or not. We have compared the paths in the walls of the Volkmann's and Haversian canals with Kihara's fluid paths, and found the paths in the bone do not belong to the category of Kihara's paths. Namely, the term "extravascular fluid path" should not be applied to the areolar tissue in the bone. We suggest the term "fluid path" for this tissue in the bone. The areolar tissue in the walls of the Volkmann's and Haversian canals and endosteum communicate with one another. We call them collectively endosteum. Yoshikawa called the areolar tissue in the Volkmann's and Haversian canals perivasculäre lymsphräume. However, this designation is inadequate considering the actual characteristics of this tissue.

Animals↗
PubMed1990

Comparative histology and histochemistry of the gastric glands of cats and dogs.

We performed histological and histochemical investigations on the gastric glands of cats and dogs. So-called cardiac glands in the cat and dog have a small number of the parietal cells and the PAS-positive glandular cells in the base of these glands contain fine pepsinogen granules. Consequently, we consider them as undifferentiated gastric glands, and can find no differences between these glands in both animals. The immature chief cells in the cat gastric glands are distributed not only in the glandular body but also in the base of the glands and contain sialomucin, and weak and strong acid mucopolysaccharides. The mature chief cells in cat and dog gastric glands contain weak and strong acid mucopolysaccharides. The gastric gland region of the dog is divided into clear and dark zones, and structural differences between the two zones are recognizable. Namely, the chief cells in the glandular base in the clear zone are somewhat undifferentiated, while the chief cells in the middle and lower parts of the glandular body and those in the glandular base in the dark zone are perfectly differentiated. The structure of the gastric glands in the fundic and greater and lesser curvature regions in the cat is very similar.

Animals↗
PubMed1990

Do the cardiac glands exist? 7. The cow.

The glands distributed in the narrow region of the abomasum contiguous to the omasum of the cow have been described as cardiac glands. We doubted this assertion and therefore performed histological and histochemical investigations of the glands to clarify their characteristics. 1. All glandular cells except the parietal cells in a few glands contiguous to the omasum react strongly to PAS, AB(pH 2.5), and PAS-AB(pH 2.5) staining, and moderately to AB(pH 0.5) staining. 2. Glandular cells at the base of these glands contain fine pepsinogen granules and a few parietal cells are distributed in these glands, indicating that they are undifferentiated gastric glands and that the so-called cardiac glands do not exist in the cow stomach. 3. Glandular cells in undifferentiated gastric glands are filled with PAS, AB(pH 2.5 and 0.5) and PAS-AB(pH 2.5) positive substances. Which gradually decrease and finally disappear with differentiation, remaining only in the neck (mucous neck cells) and the cells in the upper part of the glandular body (immature chief cells), in mature gastric glands. 4. Mature chief cells in differentiated gastric glands are distributed in the middle and lower bodies and base of the glands and contain a number of PAS and PAS-AB(pH 2.5) positive granules and a large number of coarse pepsinogen granules, while pepsinogen granules in the mucous neck cells and immature chief cells are finer. 5. In the cow the region in which undifferentiated gastric glands are located is very narrow. 6. Parietal cells in the cow stomach are numerous.(ABSTRACT TRUNCATED AT 250 WORDS)

Abomasum↗
PubMed1990

Construction of chimeric insecticidal proteins between the 130-kDa and 135-kDa proteins of Bacillus thuringiensis subsp. aizawai for analysis of structure-function relationship.

Eight chimeric insecticidal protein (IP) genes were constructed between the 130-kDa and 135-kDa IP genes of Bacillus thuringiensis subsp. aizawai, and expressed in Escherichia coli JM103 cells. The characterization of the produced chimeric IPs indicated that the variable region (VR1) in the amino-terminal half of the IPs is responsible for the insecticidal activity against larvae of Spodoptera litura and Plutella xylostella. The carboxy-terminal half of VR1 was important for the formation of the 60-kDa active fragment in the gut juice of S. litura larvae. Also, combination of the other two variable regions (VR2 and VR3), which were in the central and carboxy-terminal portions of the IPs, appeared to be related to the solubility of the IPs in the gut juice.

Animals↗
PubMed1990

[Treatment and prognosis of retinoblastoma from 1975 to 1987].

Among 21 cases of retinoblastoma (28 eyes) treated during the past 14 years in our clinic, 14 cases were unilateral, and 7 were bilateral. The average ages at the first visit were 27 months in unilateral cases and 7.2 months in bilateral cases. In all unilateral cases, in all of which the tumors were large (over group III according to Reese's classification), we removed the affected eye, and all patients survived without any evidence of metastasis or recurrence during a 5-year follow-up period. In bilateral cases, we removed the advanced eyes in which the tumors were large (over group III according to Reese's classification) in all cases, and the contralateral eyes underwent conservative treatment by radiotherapy, photocoagulation or chemotherapy. When tumors in contralateral eyes were small (Group I or II in Reese's classification), tumors of the retina subsided and all patients survived without recurrence or metastasis. However, when the tumors were large (group V), tumors of retina did not subside and survival was very poor. Our results show that the prognosis for survival in bilateral cases depends mainly upon the size of the tumor in the remaining eye.

Child↗
PubMed1990

Augmentation of antiproliferative activity of recombinant human tumor necrosis factor by delta 12-prostaglandin J2.

The effects of tumor necrosis factor (TNF) and cyclopentenone prostaglandins (PGA2 and delta 12-PGJ2), singly and in combination, against proliferation in three human gynecologic tumor cell lines (HeLa S3, HHUA, and CAOV-3) were examined in vitro. The HeLa S3 and CAOV-3 cells were unresponsive to TNF, and the HHUA cells exhibited a minimal degree of responsiveness to TNF. The HeLa S3 and HHUA cells were responsive dose-dependently to PGA2, and the CAOV-3 cells were slightly responsive to PGA2. All three cell lines were highly responsive to delta 12-PGJ2. The synergistic antiproliferative effect of TNF and delta 12-PGJ2 appeared in all three cell lines. Pretreatment with delta 12-PGJ2 enhanced the effectiveness of TNF in these cell lines, but not vice versa. A synergistic interaction between TNF and PGA2 was absent in these three cell lines. These results suggest that a combined treatment with TNF and delta 12-PGJ2 could provide a new approach to obtaining increased responses in clinical trials.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Urinary UK, t-PA and urinary trypsin inhibitor in health and glomerular diseases.

The concentrations of two different plasminogen activators(PAs), urokinase (UK), tissue-type plasminogen activator (t-PA) and urinary trypsin inhibitor (UTI) were determined in the urine and blood from 48 normal subjects and 92 patients with glomerulonephritis using highly sensitive enzyme immunoassay (EIA). The values of UK clearance were approximately 1.5-fold larger than those of creatinine clearance and at least 60.8% of UK was reabsorbed in the renal tubules, which suggest that one of major secretion site of UK is located in the outer region of the glomerular basement membrane (GBM), that is glomerular epithelium. Decreased urinary excretion of UK was observed in the glomerular disease depending on their severity and correlated with the increasing degree of FDP D-dimer excretion. On the other hand, the values of t-PA clearance were quite smaller than those of creatinine clearance, which suggest that urinary t-PA originated from the blood circulation or the inner side of the GBM (possibly glomerular endothelium) and filtrated from the GBM. Like UK, urinary t-PA also decreased in glomerular diseases. UTI which is highly anionic and has a comparable size with albumin was excreted increasingly in glomerulo-nephritis due to loss of the anionic charge barrier of the GBM. No significant correlations were noted between UTI excretion and UK or t-PA excretion.

Adolescent↗
PubMed1989

Stimulation of plasmin catalyzed conversion of single-chain to two-chain urokinase-type plasminogen activator by sulfated polysaccharides.

Influence of heparin, chondroitin sulfate C and dextran sulfate (MW 3,500 and 7,000) on plasmin catalyzed conversion of single-chain (scu-PA) to two-chain (u-PA) urokinase-type plasminogen activator and generation of plasmin in mixtures of scu-PA and Glu-plasminogen (Glu-plg) was investigated. Conversion of scu-PA to u-PA catalyzed by plasmin was enhanced by chondroitin sulfate C and heparin, maximally by 10-fold and 3-fold, respectively. Sulfated polysaccharides potentiated generation of plasmin in mixtures of Glu-plg and scu-PA, as well as enhanced plasminogenolytic activity of u-PA. The possible role of these interactions is discussed.

Catalysis↗
PubMed1989

Inhibition by tranexamic acid of the conversion of single-chain tissue plasminogen activator to its two chain form by plasmin: the presence on tissue plasminogen activator of a site to bind with lysine binding sites of plasmin.

The addition of tranexamic acid inhibited the conversion of single chain tissue plasminogen activator (sct-PA) to its two chain form (tct-PA) by plasmin. Increase in the concentrations of tranexamic acid resulted in more inhibition of the conversion, with 50% inhibition being obtained at 0.251 mM of the concentration of tranexamic acid. The addition of the fragments of plasminogen such as kringle 1 to 3 (K1-3), and K4 resulted in the facilitation of the conversion of sct-PA to tct-PA by plasmin. The addition of tranexamic acid to the mixture of sct-PA and K4 inhibited the rate of the conversion of sct-PA by plasmin. These results suggest that binding of lysine binding sites of plasmin or plasminogen with sct-PA enhanced its conversion to tct-PA by plasmin, and that there is a site on a t-PA molecule to bind to plasminogen or plasmin.

Animals↗
PubMed1989

Plasma levels of t-PA free PAI-1 and a complex of t-PA with PAI-1 in human males and females at various ages.

The concentration of tissue plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1) and the complex of t-PA and PAI-1 (t-PA-PAI-1 complex) were measured using an enzyme immunoassay, where the first antibody was monoclonal antibody against PAI-1 and the second one was polyclonal anti-t-PA Fab' antibody. Plasma levels of t-PA and t-PA-PAI-1 complex increased with increase in age in the total population of males and females, but there was no age related change in free and total PAI-1. Plasma levels of t-PA antigen were higher in males than in females, and those in females gradually increased with increase in age, reaching the same levels as those of males at their 60s. Plasma levels of t-PA-PAI-1 complex were also higher in males than in females, but the difference was low at their 50s and no difference was observed at their 60s. Plasma levels of free PAI-1 were higher in males than in females, but those of males declined at age group higher than their 50s. At their 60s plasma levels of free PAI-1 were higher in females than in males. These results indicate that fibrinolytic parameters such as t-PA and PAI-1 were balanced at higher levels in plasma in males than in females.

Adult↗
PubMed1989

Source of increased plasminogen activators during pregnancy and puerperium.

We investigated the increase of plasminogen activators (tPA and uPA) in the plasma during pregnancy. Both tPA and uPA antigens were found to increase after the third trimester of pregnancy and high levels of PAs persisted through the first stage of labor. The tPA antigen levels rose further for the first few hours post-partum, while the level of uPA antigen returned to normal immediately following childbirth. To clarify whether the uterus and/or placenta are involved in the increased levels of plasma PAs, the levels were measured in uterine venous blood in cases of caesarean sections. During the ante-partum period, the level of uPA antigen in the uterine venous blood was higher than that in the peripheral venous blood, while there was no significant difference between the levels of tPA antigen in peripheral blood and uterine venous blood. The level of tPA antigen in the uterine venous blood rose after delivery. In contrast, the level of uPA antigen declined immediately after delivery. These results suggest that (1) the placenta is the major source of the increased uPA antigen during pregnancy, (2) entire vascular system is involved in the increased tPA antigen during pregnancy, (3) a further increase in tPA after delivery is due to the release of this enzyme from the involuting uterus.

Antigens↗
PubMed1989

The conversion of streptokinase-plasminogen complex to SK-plasmin complex in the presence of fibrin or fibrinogen.

When equimolar amounts of Glu-plasminogen (Glu-plg) and streptokinase (SK) were mixed in the presence of S-2251, SK-plg complex was formed and only gradually converted to SK-plasmin complex. When equimolar amounts of Glu-plg and SK were mixed with fibrinogen or fibrin, Glu-plg was converted faster to plasmin suggesting that Glu-plg molecule in the complex was converted to plasmin. It is thus concluded that SK-plg complex is converted to SK-plasmin complex slowly in the absence of fibrin or fibrinogen. When SK-plg-fibrin(ogen) complex was formed, plasminogen moiety was converted to plasmin faster inside a trimolecular complex of SK, plasminogen and fibrin(ogen).

Autoradiography↗
PubMed1989

Absence of synergism between tissue-type plasminogen activator and urokinase on plasminogen activation rate in plasma.

Effects of tissue-type plasminogen activator (t-PA), urokinase (u-PA) and their combinations on plasminogen activation rate (PAR) in plasma, in vitro were investigated. T-PA and u-PA over concentrations range of 10 U/ml to 50 U/ml induced a linear, concentration dependent increase in PAR. Combinations of t-PA and u-PA in ratios of 3/1, 1/1 and 1/3 induced additive but not synergistic effect in the activation of plasminogen. We conclude, therefore, that t-PA and u-PA do not act synergistically in the activation of plasminogen in plasma in vitro.

Chromogenic Compounds↗