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Biomedical subjects

M Takayama

Publications and source records attributed to M Takayama.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Isolation and purification of pregnancy-associated plasma protein A].

We tried to purify pregnancy-associated plasma protein A (PAPP-A) from normal term maternal serum in this study by means of a three step chromatographic procedure. At first 30 ml of maternal serum samples were applied to a column for sieve chromatography and eluted according to molecular weight. PAPP-A was detected in the high molecular weight fraction area by radioimmunoassay for PAPP-A, and 91% of the total amount of PAPP-A in the maternal samples was recovered. Secondary PAPP-A containing fractions were applied to a Heparin-Sepharose column and eluted by a stepwise increase in NaCl 0.15, 0.30 and 0.60 M in 0.05 M Tris-HCl buffer, pH 7.8. Ninety-three percent of PAPP-A in applied samples was recovered under the 0.6 M NaCl condition. Thirdly the pooled fractions which contained PAPP-A after Heparin-Sepharose affinity chromatography were applied to DEAE-Sephacel Chromatography and eluted by a stepwise increase in NaCl 0.15, 0.30 and 0.45 M in 0.01 M acetate buffer, pH 5.5. Ninety-one percent of PAPP-A in applied samples was recovered under the 0.3 M NaCl condition. Finally PAPP-A containing fractions were concentrated 10 times and 3.8 IU (1.7 mg) of PAPP-A was isolated. The purification schedule removed approximately 99% of total protein in the maternal serum while 74% of PAPP-A was recovered. The purification factor (fold), which was calculated as the increase in specific activity (mIU:PAPP-A/mg:protein) in comparison with the starting value in the maternal serum, was 526. And the purity (mg:PAPP-A/mg:protein) of the final product was 68.4%. Analysis of the final purified material by SDS-PAGE showed a single band of 200kDa, and western blot analysis showed that the main purified protein was PAPP-A. The immunological identity of the PAPP-A purified in this study to the PAPP-A donated by Teisner et al., was recognized by crossed immunoelectrophoresis and tandem crossed immunoelectrophoresis. We hope that the new PAPP-A purified in this study can be utilized for the development of a sensitive and convenient assay for PAPP-A and its standard material, and also for basic study to clarify the biological function of PAPP-A in the human body.

Blotting, Western↗
PubMed1996

[Usefulness of newly developed subcutaneous one point lifting method in gynecological laparoscopic operation].

We first introduced the abdominal wall lifting method in gynecological laparoscopic operations in 1994. Now we have developed a new one-point lifting technique (Tokyo Medical College method) that enables gynecological laparoscopic operations to be performed more safely, easily and economically. 1. The TMC method provides a sufficiently spacious operative field in the same way as artificial pneumoperitoneum and can overcome the negative influence of obesity on the operative field. 2. Because the abdominal wall is lifted up by means of a single stainless steel wire passed under the skin in this method, the limitations of previous methods are completely overcome. Furthermore setting up for this method is very easy and can be completed in a short time. 3. Because the aperture for the Surgigrip made in the abdominal wall is short and has a large internal diameter, we can manipulate operative instruments freely. Especially suturing and ligation can be carried out simply and accurately. 4. We were able to continue irrigation and suction without deterioration of the operative field and to easily remove resected tissue from the abdominal cavity. 5. The frequency of intracorporeal suture and ligation in this method increased significantly compared with the pneumoperitoneum method in cases of ovarian diseases. As a result, most operative procedures in ovarian diseases became cystectomies, preserving the healthy part of the ovary. This also reduced operative cost by avoiding expensive autosuture equipment. 6. There were no complications such as subcutaneous bleeding with this method. There was no significant difference between this method and pneumoperitoneum in terms of postoperative pain. The TMC method is a new laparoscopic operative technique that allows procedures to be performed under conditions close to laparotomy procedures and solves most of the problems of the pneumoperitoneum method.

Abdominal Muscles↗
PubMed1996

[Measurement of serum tissue polypeptide antigen (TPA) in patients with malignant tumor using prolifigen TPA-M "Daiichi" kit].

Serum tissue polypeptide antigen (TPA) was measured using a newly developed Prolifigen TPA-M "Daiichi" kit in 1,236 healthy subjects, 2,867 patients with malignant tumors, and 901 with benign diseases. Because 94.0% of healthy subjects had serum TPA under 70 U/l, the cut-off value was set at 70 U/l. Serum TPA was elevated in more than 50% of patients with head and neck cancer, lung cancer, liver cancer, gallbladder or bile duct cancer, pancreatic cancer, colorectal cancer, ovarian cancer, and prostate cancer. The overall positive rate in malignant tumors was 55.5%. Serum TPA was higher in advanced cancer than in earlier stage cancer, and decreased after the resection of the tumor. The false positive rate in benign diseases was 31.3%. ROC analysis revealed the usefulness of TPA as a tumor marker in many cancers. The correlation coefficient between TPA and CYFRA 21-1, and between TPA and TPSA, was 0.747 and 0.694, respectively. In conclusion, measurement of serum TPA using the new kit is useful in the management of patients with various malignant tumors.

Antigens, Neoplasm↗
PubMed1996

Hyaluronic acid increases proteoglycan synthesis in bovine articular cartilage in the presence of interleukin-1.

Osteoarthritis is a common joint disorder in humans. Although intra-articular injection of hyaluronic acid (HA) is in widespread clinical use, there are limited data on the effect of HA on degenerated cartilage. When bovine articular cartilage is degraded with interleukin-1, HA penetrates the cartilage and accumulates in the pericellular matrix of chondrocytes. HA also enhances proteoglycan synthesis that has been reduced by interleukin-1. Thus HA seems to have anabolic effects on degraded cartilage.

Animals↗
PubMed1996

[Analysis of the mechanism of trophoblast infiltration].

A cytotrophoblast (CT) infiltrates into the stroma, forming an extravillous trophoblast (EVT) in the placenta early in gestation and the phenomenon is strictly controlled, differing from the infiltration of cancer cells. The expression of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9), which deeply involve infiltrative metastasis of cancer, and the reactivity to transforming growth factor beta 1 (TGF beta 1), which controls the expression of these MMPs and inhibits the growth of epithelial cells, were investigated in CT derived from villi at normal gestational week 6 (early CT) and CT derived from villi at normal gestational week 37 (full-term CT), and also the choriocarcinoma cell line BeWo (BeWo). The ability of normal epithelial cells and BeWo cells to proliferate and infiltrate were evaluated in vitro by northern blotting, gelatin zymography, and invasion assay. It was revealed that early CT had a higher capacity for infiltration than full-term CT as well as BeWo. MMP2 and MMP9 appeared in the early CT, whereas only MMP9 was observed in the full-term CT. MMP2 and MMP9 were more abundantly observed in the early CT and the full-term CT rather than in BeWo. In uterine stroma-derived cells, membrane type matrix metalloproteinase (MT-MMP), which activates MMP2, was observed. These results indicated that the motility of normal villous cells was higher in the early CT than in the full-term CT. The expression of MMP2 in the early CT, which was not observed in the full-term CT, was thought to be related to this difference in motility. As for the responsiveness to TGF beta 1, which is a growth inhibiting factor for epithelial cells, the villous carcinoma cell line was insensitive to the growth inhibiting effect of TGF beta 1, but the early CT was sensitive to this effect. When TGF beta 1 was added, MMP2 and MMP9 increased in the early CT. This response was also seen in BeWo. That is, it was assured that the growth capacity was not inhibited in BeWo, but was certainly inhibited in the early CT. The overall results of these evaluations indicated that the development to EVT by infiltration of the early CT was associated with the increase in the mobility of cells caused by MMP2 and the increase in amounts of MMP2 and MMP9 caused by TGF beta 1, and the predominant inhibitory effect of TGF beta 1 on the growth of normal epithelial cells could explain why normal epithelial cells do not grow as cancer cells do.

Animals↗
PubMed1996

[Combined effects of sizofiran and rG-CSF on myelosuppression in cancer chemotherapy].

A combination of the antitumor polysaccharide Sizofiran and rG-CSF was investigated for its effects on peripheral blood counts in ovarian cancer patients undergoing chemotherapy. We performed the analysis by using variations in peripheral blood counts and the duration of treatment as variables. In the analysis, effects on decreases in both neutrophils and platelets and their recoveries could be assessed. As a result, the decrease in neutrophils was inhibited and its recovery was promoted, suggesting that the combined use of the drugs may be useful for myelosuppression by chemotherapy for ovarian cancer.

Adult↗
PubMed1995

Enhanced effect of epidermal growth factor on pulmonary metastasis and in vitro invasion of rat mammary carcinoma cells.

We examined the effects of epidermal growth factor (EGF) on metastatic and in vitro invasive capacity of weakly malignant ER-1 cells derived from a rat mammary carcinoma cell line, c-SST-2. EGF enhanced the metastatic capacity and in vitro invasiveness to reconstituted basement membrane, Matrigel, of ER-1 cells in a dose-dependent fashion. EGF-stimulated invasiveness was inhibited by anti-EGF antibody, which is able to neutralize the binding of EGF to EGF receptor, in the invasion assay system. EGF stimulated chemotactic migration toward fibronectin, laminin or newborn rat fibroblast-conditioned medium which was used as a chemoattractant in the in vitro invasion assay, but showed neither adhesion to Matrigel nor production of gelatinase and plasminogen activators. These results suggested that the increased metastatic and invasive capacity of ER-1 cells by EGF might be due to the increase in cell motility.

Animals↗
PubMed1995

Zonal differences in nitric oxide synthesis by bovine chondrocytes exposed to interleukin-1.

To determine the role of nitric oxide (NO) in the inhibition of aggrecan synthesis, we measured levels of NO produced by bovine chondrocytes from different layers of articular cartilage in the presence of interleukin-1 (IL-1). Chondrocytes from the superficial layer showed a large increase in NO synthesis in response to IL-1. Although chondrocytes from the deep layer also produced NO in response to IL-1, the amount was less than that from the superficial layer. Enhanced NO production evoked by IL-1 was accompanied by a significant inhibition of aggrecan synthesis. These data suggest that chondrocytes in both superficial and deep layer of articular cartilage inhibit aggrecan synthesis with IL-1 via NO production. In addition, superficial layer cells respond to lower amounts of IL-1 with respect to NO-production and inhibition of proteoglycan synthesis.

Animals↗
PubMed1995

Appearance of free radicals in the guinea pig inner ear after noise-induced acoustic trauma.

The emergence of superoxide anion radicals (O2-) in the guinea pig inner ear following acoustic trauma was investigated by histochemical methods. Five minutes after exposure to sound at 120-125 dB SPL for 3 h, an O2- reaction product was detected in the cochlea along the luminal membrane of the marginal cells of the stria vascularis. This reaction product could not be found at 30 min, but reappeared at 2 h. The first appearance of O2- is not explainable by our studies, but the second appearance may be related to recirculation of strial blood flow after blood flow stasis. The present observations raise the possibility that free radicals are produced in the inner ear after acoustic trauma and lead to inner ear damage.

Animals↗
PubMed1995

Cyclic change in 3 alpha-hydroxysteroid dehydrogenase in rat ovary during the estrous cycle.

3 alpha-Hydroxysteroid dehydrogenase (3 alpha-HSD) activity and content in the rat ovary were measured at various stages of the estrous cycle, and the enzyme protein in the ovary was localized by immunohistochemistry. The cyclic change of ovarian 3 alpha-HSD activity towards 5 alpha-dihydrotestosterone (5 alpha-DHT) as a substrate was characterized by two peaks. The first peak occurred at 0800 h on proestrus; then the reductase activity decreased and reached its minimum at 2000 h on proestrus. Thereafter, it gradually increased, reaching the second peak (170% of the value at 2000 h on proestrus) at noon of estrus. Quantitative analysis by immunoblotting revealed that the alteration in 3 alpha-HSD content in the rat ovary during the estrous cycle was essentially similar to that in 5 alpha-DHT reductase activity. Changes in the reductase activities towards 5 alpha-androstane-3,17-dione and 5 alpha-DHT and in the dehydrogenase activity towards androsterone in the ovary were entirely different from those in the 5 alpha-DHT reductase activity and 3 alpha-HSD content; on the other hand, the change in carbonyl reductase activity towards p-nitroacetophenone was similar to changes in 5 alpha-DHT reductase activity and 3 alpha-HSD content. Therefore, p-nitroacetophenone may be a useful substrate, instead of 5 alpha-DHT, for detection of 3 alpha-HSD activity at a high sensitivity, since the p-nitroacetophenone reductase activity was 10-fold higher than the 5 alpha-DHT reductase activity. The enzyme was primarily localized in the granulosa cells and CL cells. At 2000 h on proestrus, however, the overall intensity of immunostaining in the granulosa cells of the Graafian follicles was markedly diminished. In addition, immunoreactivity in the CL cells at 0800 h on estrus was observed only in the cells outlining the CL in some cases.

3-Hydroxysteroid Dehydrogenases↗
PubMed1995

Accumulation of glutamate by osmotically stressed Escherichia coli is dependent on pH.

In the present study, we measured the accumulation of glutamate after hyperosmotic shock in Escherichia coli growing in synthetic medium. The accumulation was high in the medium containing sucrose at a pH above 8 and decreased with decreases in the medium pH. The same results were obtained when the hyperosmotic shock was carried out with sodium chloride. The internal level of potassium ions in cells growing at a high pH was higher than that in cells growing in a neutral medium. A mutant deficient in transport systems for potassium ions accumulated glutamate upon hyperosmotic stress at a high pH without a significant increase in the internal level of potassium ions. When the medium osmolarity was moderate at a pH below 8, E. coli accumulated gamma-aminobutyrate and the accumulation of glutamate was low. These data suggest that E. coli uses different osmolytes for hyperosmotic adaptation at different environmental pHs.

Adaptation, Biological↗
PubMed1995

Immunohistochemical localization of V2 vasopressin receptor along the nephron and functional role of luminal V2 receptor in terminal inner medullary collecting ducts.

We investigated immunohistochemical localization of V2 vasopressin receptor along the nephron using a specific polyclonal antibody. Staining was observed in some of thick ascending limbs and all of principal and inner medullary collecting duct (IMCD) cells. Not only basolateral but also luminal membrane was stained in collecting ducts, especially in terminal IMCD (tIMCD). To learn the functional role of luminal V2 receptor in tIMCD, we studied the luminal effects of arginine vasopressin (AVP) on osmotic water permeability (Pf), urea permeability (Pu), and cAMP accumulation using isolated perfused rat tIMCD. In the absence of bath AVP, luminal AVP caused a small increase in cAMP accumulation, Pf and Pu, confirming the presence of V2 receptor in the lumen of tIMCD. In contrast, luminal AVP inhibited Pf and Pu by 30-65% in the presence of bath AVP by decreasing cAMP accumulation via V1a or oxytocin receptors and by an unknown mechanism via V2 receptors in the luminal membrane of tIMCD. These data show that V2 receptors are localized not only in the basolateral membrane but also in the luminal membrane of the distal nephron. Luminal AVP acts as a negative feedback system upon the basolateral action of AVP in tIMCD.

Amino Acid Sequence↗
PubMed1995

Presence and regulation of Raf-1-K (Kinase), MAPK-K, MAP-K, and S6-K in rat nephron segments.

Renal nephron segments are heterogeneous, and receptors for endothelin (ET)-1, ET-3, Angiotensin II (AII), epidermal growth factor (EGF), and insulin-like growth factor I distribute differently along the nephron segments. Recently, growth factors and vasoactive substances are reported to stimulate mitogen-activated protein kinase (MAP-K). In this study, we showed that mRNA and proteins of MEK-K, Raf-1-K, MAPK-K, MAP-K (p42 and p44), and S6-K are expressed ubiquitously in intact nephron segment. We demonstrated that four tiers of a cascade composed of the Raf-1-K, MAP-K, MAP-K, and S6-K are stimulated by ET-1 and ET-3 in rat intact glomeruli (Glm) via primarily B-type ET receptors and PKC. The stimulatory effect of EGF and IGF-I to MAP-K activity is inhibited by a tyrosine kinase inhibitor in Glm. IGF-I significantly stimulates MAP-K activity and EGF and All moderately stimulate MAP-K activity in the proximal convoluted tubule (PCT). EGF significantly increased MAP-K cascades and ET-1 and ET-3 slightly increased MAP-K cascades in the medullary thick ascending limb (MTAL). EGF significantly stimulated MAP-K cascades, and ET-1 and ET-3 moderately stimulate MAP-K cascades in the outer medullary collecting duct (OMCD) and the inner medullary collecting duct (IMCD). MAPK-K and S6-K are similarly stimulated by these agonists in each segment. This study shows that MAP-K cascades are expressed in every nephron segment. ET-1, ET-3, All, EGF, and IGF-I stimulate MAP-K cascades heterogeneously along the nephron segment. It was concluded that MAP-K cascades play an important role in the regulation of renal function.

Animals↗
PubMed1995

Mechanical properties of human round window, basilar and Reissner's membranes.

In order to measure the mechanical strength of small and delicate biological specimens, a microtesting system was developed. We measured the mechanical properties of the round window, basilar and Reissner's membranes taken from the autopsied cases. The testing method was a displacement of the specimen by a force sensor needle until rupture. A load-displacement curve was then drawn and the mechanical value of each specimen was calculated. Reissner's membrane was the weakest, though it showed a measurable strength. From the load-displacement curve of the basilar membrane, it could be displaced by a smaller force than the rupture strength of Reissner's membrane. Speculation about the concept of a negative summating potential in Meniere's disease is therefore theoretically possible from a mechanical point of view.

Aged↗
PubMed1995

The emergence of free radicals after acoustic trauma and strial blood flow.

The effect of acoustic trauma on cochlear strial circulation was investigated immunohistologically in the guinea pig. Kanamycin was used as a tracer of blood flow. Moreover, histochemical examinations were made to reveal the emergence of free radicals in the cochlea following acoustic trauma. At 5 min (5 min after intense sound exposure 120-125 dB SPL, 3 h) the blood flow in the stria vascularis was greatly diminished. At 2 h the strial blood flow started to recirculate and at 6 h it appeared to have returned to normal. Superoxide anion radicals (O2-) emerged along the luminal membrane of the marginal cells of the stria vascularis at 5 min. O2- disappeared at 30 min, but reappeared at 2 h. The cause of its emergence at 5 min was obscure. However, the strange phenomenon that O2- emerged again at 2 h seemed ascribable to the re-circulation of strial blood flow after sound exposure.

Animals↗
PubMed1995

[Superselective local infusion therapy with tissue-plasminogen activator for acute massive pulmonary thromboembolism: preliminary clinical experience].

Three cases of acute massive pulmonary thromboembolism were treated with the superselective infusion of tissue-plasminogen activator. Superselective pulmonary angiography immediately after administration of tissue-plasminogen activator demonstrated angiographic improvement in all patients. No complications were encountered during or after the procedure. It is considered that superselective infusion of tissue-plasminogen activator can be an effective therapy for massive pulmonary thromboembolism.

Acute Disease↗