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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 577 records · Page 32Linked to original sources

Pathology of anomalous junction of the pancreaticobiliary ductal system: mutagenicity of the contents of the biliary tract and nuclear atypia of the biliary epithelium.

Congenital biliary dilatation is frequently complicated by biliary tract cancer, and anomalous junction of the pancreaticobiliary ductal system, a major factor constituting the pathology of this disease, is considered to be important as a background for carcinogenesis in the biliary tract. To clarify the mechanism of carcinogenesis in the biliary tract under the circumstance of anomalous junction, we evaluated the mutagenicity of the contents of the biliary tract in patients with congenital biliary dilatation and analyzed the nuclear atypia of the biliary epithelium by fluorocytometry. A mutagenicity test using Bacillus subtilis showed positive results in 6 of 12 patients. Since mutagenicity correlates well with carcinogenicity, these results suggest the necessity of separation surgery between the bile and pancreatic ducts in patients with anomalous junction regardless of the presence or absence of biliary dilatation. On the other hand, DNA histograms of the nuclei of gallbladder epithelial cells produced by fluorocytometry in 4 patients revealed a high incidence of polyploid DNA in 2 patients with marked hypertrophic changes. These patients were also positive for mutagenicity of the contents of the biliary tract, suggesting that mutagens are involved in the atypia at the cellular and nuclear levels.

Adolescent↗

Adhesion mechanism of polyelectrolyte cements to tooth structure--polyelectrolyte behavior of the cement polymers obtained by potentiometric titration in the presence of calcium ion.

Potentiomeric titration of aqueous solutions of polyacrylic acid and commercial polyelectrolyte cement polymers with sodium hydroxide solution was carried out in the presence of different concentrations of Ca2+. Polyelectrolytes all behave as weak acids without the coexisting Ca2+. However, in the presence of Ca2+, in amounts over one-half of the equivalent amount to the carboxyl group in the polymer, they have a strong acid-like behavior. This means that the carboxyl groups in the polymer chain tend to react strongly with coexisting Ca2+ as they are partially neutralized by the alkaline solution. This is also strong evidence supporting polyelectrolyte cement as an adhesion mechanism to tooth structure during cementation.

Acrylic Resins↗

[A clinicopathological study of early mucinous adenocarcinoma of the stomach].

From 1963 to 1986, 1126 cases (1300 lesions) of early gastric carcinoma were treated at Fukui Prefectural Hospital. Mucinous adenocarcinomas comprised 16 lesions in this series. These cases of mucinous adenocarcinoma were younger than all the other early carcinomas of the stomach and they often were locted in the lower third of the stomach. Macroscopically, most were types "Iia + IIc". Dividing them into 3 grouping: papillary, tubular, and signet ring cell types, depending on the microscopic appearance of the intramucosal carcinoma, the signet ring cell group differed from the other two as to age, macroscopic appearance, and region it occupied. An immunochemical study showed that CA19-9 stained positively in a mucous lake, much like a carcinoma cell, but that CEA stained little.

Adenocarcinoma↗

In vitro study on the corrosion behavior of three commercial Ag-Pd-Cu-Au alloys in Ringer's and 0.1%Na2S solutions.

The corrosion resistance of three commercial Ag-Pd-Cu-Au alloys was estimated in Ringer's and 0.1% Na2S solutions by electrochemical techniques and surface analyses. In Ringer's solution, the three alloys showed high corrosion resistance and there was no significant difference in the anodic polarization characteristics of the three alloys. In the 0.1% Na2S solution, the Alloy A which had the lowest noble metal content (Au + Pd) exhibited the highest anodic reactivity with the largest amount of corrosion product on the alloy surface. It was determined that the Ag-rich phase of Ag-Pd-Cu-Au alloy was preferentially attacked to form Ag2S corrosion product. The polarization resistance data showed that the corrosion rate for Alloy A in 0.1% Na2S solution was determined to be 500 times higher than that in Ringer's solution. The corrosion rate of the alloy in the freely corroded condition can be estimated quantitatively and precisely by measuring the polarization resistance.

Copper↗

[Severe postoperative pulmonary hypertensive crisis in a case of ventricular septal defect with Down's syndrome].

We encountered the episode of severe postoperative pulmonary hypertensive crisis in a case of ventricular septal defect with Down's syndrome. A 1 year 11 month old female with ventricular septal defect and pulmonary hypertension underwent open heart surgery. On the operative day after tracheal suction she experienced bradycardia, hypotension and pulmonary hypertension followed by shock condition. In spite of vigorous medical therapy clinical aspects were not improved. But only blood transfusion directly into the left atrium and administration of tolazoline hydrochlorides through pulmonary artery were very effective to improvement of hemodynamics and reduction of pulmonary hypertension. Moreover, after this episode pulmonary artery pressure showed elevation at the tracheal suction and the weaning from the respirator. We discussed the cause and treatment of postoperative pulmonary hypertensive crisis.

Down Syndrome↗

[Effects of combined instillation of dapiprazole and epinephrine on human anterior chamber depth, intraocular pressure and pupil diameter].

Pilocarpine, a first choice drug for primary angle closure glaucoma (PACG), is reported to produce shallow anterior chamber and posterior synechia and consequently a small immobile pupil. In this paper, dapiprazole, a newly synthesized alpha 1 blocker, was given topically in combination with epinephrine eye drops to 15 healthy volunteers and 10 patients with PACG. In both volunteers and patients, the treated eyes revealed deeper anterior chambers, thinner lenses and significant IOP reduction after the combined instillation of dapiprazole and epinephrine. Though light reaction was preserved, mild miosis was observed in volunteers, but no pupillary change in patients. The conjunctival hyperemia induced by dapiprazole was reversed by additional instillation of epinephrine. Burning sensation was the only side effect observed after instillation of dapiprazole. In conclusion, the combined instillation of dapiprazole and epinephrine appears to be a good choice for the therapy of PACG.

Adrenergic alpha-Antagonists↗

[Prolymphocytic leukemia associated with serum hypo IgA].

A 69-year-old man was admitted for the evaluation of leukocytosis with atypical cells. Physical examination revealed marked hepatosplenomegaly. The peripheral blood demonstrated Hb 10.1 g/dl, platelet 13.6 x 10(4)/microliters, and WBC 14200/microliters with 76% lymphoid cells. Bone marrow showed 52.4% lymphoid cells. These cells had a nucleus which was relatively large with a coarse chromatin structure and one prominent nucleolus. Under electron microscopy, these cells had a narrow cytoplasm containing a few mitochondria with some microvilli. The surface of these cells was positive for Ia, B1, B2, C3R, and had markedly elevated IgM-K and IgD-K surface immunoglobulins. Levels of IgG, IgA and IgM were 1140 mg/dl, 53 mg/dl, and 198 mg/dl respectively. He was diagnosed as having B-PLL, and was treated with vincristine, cytarabine and prednisolone. Since B-CLL frequently in accompanied by reduced levels of one or several immunoglobulins, and the most significant is the decrease of IgA, it is speculated from our case that B-PLL is very similar to B-CLL in the abnormalities of B cell function.

Agammaglobulinemia↗

[Aortic aneurysm associated with coarctation of the aorta].

An 8-year-old female of coarctation of the aorta associated with thoracic aortic aneurysm is reported. Under cardiopulmonary bypass, a 7 cm section of the aorta containing the aneurysm and coarctation was resected and replaced by a 16 mm woven Dacron tube. The postoperative recovery was complicated by chylothorax treated by thoracic aspiration. She is doing well 3 months after the operation. Histologic sections of the resected portions of the thoracic aorta revealed intimal hyperplasia, medial fibrosis and decrease of elastic fibers, especially in the aneurysm.

Aorta, Thoracic↗

[Analysis of mediastinal lymphadenopathy in sarcoidosis with transesophageal ultrasonic endoscopy; influences on cardiovascular system].

We studied influences of mediastinal lymphadenopathy on cardiovascular system in nine cases of sarcoidosis with transesophageal ultrasonic endoscopy. Chest x-ray films revealed bilateral hilar lymphadenopathy in all cases, whose diagnoses were made histologically with biopsies of peripheral lung through flexible fiber optic bronchoscope and/or of lymph nodes. These findings were typical in this disease. Many compartments of cardiovascular system in mediastinal and hilar regions were visible with this technique in all subjects. And enlarged lymph nodes changed dimensions in these compartments, especially in main pulmonary arteries, left atria, pulmonary veins and aorta. Furthermore, these phenomena were seen in azygos vein and superior caval vein in some cases. It is suggested that these lymph nodes may influence hemodynamics in above-mentioned compartments of cardiovascular system, if this phenomenon deteriorates more progressively.

Adolescent↗

[Early carcinoma of the gastric remnant: pathological features relating to the interval between the initial and second surgery].

Twenty cases of early carcinoma of the gastric remnant have been treated at our hospital and examined clinico-pathologically. In 11 cases, the interval after the initial gastrectomy, due to the gastric carcinoma, was done was short compared with length of the interval of 9 cases after a gastrectomy for a benign gastric disease. There were two types of gastric remnant carcinomas in cases in which the interval extended 10 years. The first type developed at the site of the gastro-intestinal anastomosis, especially when the anastomosis was found to be joined by the Billroth II method, and the carcinoma was associated with a gastritis cystica polyposa (GCP). The other type showed a polypoid appearance except for the stomal site.

Adenocarcinoma↗

[Amygdaloid kindling in weanling rat and rekindling upon maturization].

To understand the epileptic phenomenon in the immature brain and to investigate whether or not the epileptogenesis acquired in young age is retained after maturation, we carried out the amygdaloid kindling preparation (AM-K) on rat. Ten 3-week-old Wistar rats (3-week-old group) and ten 10-week-old rats (10-week-old group) were stimulated every 2 hours during 09:00-17:00, from five days after operation (Experiment 1). Nine kindled weanling rats (K-group) and ten weanling rats with no stimulation only electrodes implantation (non-K-group) were rekindled upon maturization (Experiment II). Stages of AM-K were classified according to the criteria of Racine. The results obtained were as follows: 1) The 3-week-old group needed significantly fewer stimulations and a shorter AD-durations during early stages (C0-2) of amygdaloid kindling, in comparison with the 10-week-old group. However, there was no significant difference between the two groups as to stimulations and AD-duration during later stages (C3-4) of the kindling. 2) The K-group were rekindled significantly fewer stimulations and a shorter AD-durations than non-K group during early stages. On the other hand, there was not significant difference between the two groups as to stimulation and AD-duration during later stages of the kindling. From the results, the following conclusions were made; The seizure susceptibility of weanling rat's limbic system is high and the epileptogenesis in the limbic system can be maintained even up to adulthood.

Age Factors↗

RS-5186, a novel thromboxane synthetase inhibitor with a potent and extended duration of action.

RS-5186, sodium 6-[2-[1-(1H)-imidazolyl]methyl-4,5-dihydrobenzo[b]thiophene]- carboxylate, inhibited platelet thromboxane A2 (TXA2) synthetase with IC50 values of 6 nM and 13 nM for human and rabbit microsomes, respectively. It had a selectivity for TXA2 synthetase 10(5)-fold greater than that for cyclooxygenase, PGI2 synthetase, 5-lipoxygenase and phospholipase A2. When administered orally or intravenously to dogs at 1 mg/kg, RS-5186 suppressed serum TXB2 levels almost completely with sustained duration of action: the suppression during 0.5 hr to 8 hr after dosing was more than 90%, and was 70-80% at 24 hr. Similar suppression of serum TXB2 levels was observed in rats and rabbits. Such suppression by RS-5186 was more potent than that by OKY-046 and CV-4151. Serial administration of RS-5186 (0.1 mg/kg/day p.o.) to dogs for 7 days decreased the serum TXB2 levels constantly during the medication, and no rebound phenomenon was observed after the medication was stopped. In a thrombotic model induced by sodium arachidonate injection in rabbits, RS-5186 at 1 mg/kg p.o. completely protected against sudden death (ED50 = 0.12 mg/kg, 1 hr after dosing) and this protective effect extended over 8 hr. All these results show that RS-5186 is a potent and highly selective TXA2 synthetase inhibitor with a long duration of action, and suggest that the compound could be useful in diseases where TXA2 is involved.

Animals↗

Immunochemical characteristics of hepatitis B e antigen subspecificities, HBeAg/1 and HBeAg/2.

The molecular interrelation between hepatitis B e Ag 1 (HBeAg/1) and HBeAg/2 was examined immunochemically. Major polypeptides with m.w. around 17,000 (P17) and one minor polypeptide with m.w. 18,000 (P18) that had HBeAg activity were consistently detected in 12 different serum samples by immunoblotting analysis. To examine the polypeptide composition of HBeAg/1 and HBeAg/2, precipitin lines of HBeAg/1-anti-HBeAg/1 and HBeAg/2-anti-HBeAg/2 were separately cut from the agarose gel and analyzed by immunoblotting. HBeAg/1 and HBeAg/2 showed similar P17 and P18 compositions. Monomeric forms of P17 and P18 in a solution of 0.1% SDS showed HBeAg/1 activity, whereas polymeric forms of these polypeptides showed HBeAg/2 activity. The stability of HBeAg subspecificities to SDS and 2-ME was examined. When HBeAg was incubated in a buffer containing 0.1% SDS and 0.1% 2-ME, only the HBeAg/2 precipitin line disappeared in agarose gel concurrently with the conversion of HBeAg molecules to a monomeric from a polymeric form. In contrast, neither monomerization nor the disappearance of HBeAg/2 was seen when SDS or 2-ME was used by itself. These results indicate that hydrophobic forces and disulfide bonds may be involved in the association of P17 and P18 in serum and that HBeAg/2 activity depends upon association of HBeAg-polypeptides but that HBeAg/1 activity does not. The possibility that the epitopes of HBeAg/2 are specific for the conformation of polymerized molecules is discussed.

Electrophoresis, Polyacrylamide Gel↗

Gene structure of the human mitochondrial adenosine triphosphate synthase beta subunit.

The mitochondrial ATP synthase beta subunit is encoded by a nuclear gene and assembled with the other subunits encoded by both mitochondrial and nuclear genes. As the next step in the analysis of the molecular mechanisms coordinating the two genetic systems, the gene for the human beta subunit was cloned, and its structure was determined. The gene contains 10 exons, with the first exon corresponding to the noncoding region and most of the presequence which targets this protein to the mitochondria. Eight Alu repeating sequences including inverted repeats were found in the 5' upstream region and introns. An S1 nuclease protection experiment revealed two initiation sites for the transcription. A typical TATA box was not present at about 30 base pairs upstream from either initiation site. Three CAT boxes (CCAAT) were found between the two initiation sites. In addition, one CAT box was found 41 base pairs upstream from the first initiation site. Two GC boxes (potential Sp1 binding sites) were located in the 5' upstream region, one of them linked to Alu repeating sequences. For determination of the promoter activity, fragments of various length from the 5' upstream region were fused to a chloramphenicol acetyltransferase gene and transfected into cultured cells. This experiment showed the existence of an enhancing, structure(s) for transcription between nucleotide -400 and -1100 in the upstream region.

Amino Acid Sequence↗