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Biomedical subjects

M Tani

Publications and source records attributed to M Tani.

At least 397 records · Page 22Linked to original sources

Evaluation of combined valvular prolapse syndrome by two-dimensional echocardiography.

The patterns of aortic and tricuspid valve motion in 50 patients with mitral valve prolapse were analyzed by wide-angle, phased-array, two-dimensional echocardiography. Twelve patients (24%) had redundant aortic leaflets bulging into the left ventricular outflow tract during diastole. Eight of 12 patients had aortic regurgitation and seven of 12 had M-mode echocardiographic evidence of aortic valve prolapse. One patient underwent mitral and aortic valve replacement, and the excised valves revealed marked myxomatous degeneration. Eight of 15 patients undergoing contrast echocardiography had tricuspid regurgitation (systolic reflux of contrast material into the inferior vena cava persisting for more than 10 beats), and prolapse in the septal leaflet of the anterior leaflet or both. A similar tricuspid valve pattern was noted in three of seven patients without tricuspid regurgitation. Tricuspid valve prolapse was identified in 20 patients (40%). Nine patients (18%) had combined prolapse of the mitral, aortic and tricuspid valves. In five patients with middiastolic high-pitched murmurs recorded along the left sternal border, tricuspid valve prolapse was demonstrated. In one of these patients, the presence of pulmonary regurgitation was confirmed by intracardiac phonocardiography. We conclude that two-dimensional echocardiography is useful for evaluating patients with combined valvular prolapse syndrome.

Adolescent↗

[Evaluation of mitral valve, subvalvular structures and valvular flexibility in mitral stenosis by two-dimensional echocardiography].

UNLABELLED: In order to identify the determinants for surgical procedures in mitral stenosis, we evaluated two-dimensional echocardiographic findings of the mitral valve and subvalvular structures in 35 patients undergoing open mitral commissurotomy (OMC) or valve replacement (MVR). As indices of a degree of subvalvular shortening and valvular flexibility, the distance between the mitral ring and the tip of the anterior mitral leaflet was measured by the LV long-axis view by in both midsystole (S) and early diastole (D). As a possible major determinant for MVR, a degree of valvular calcification (C) was semi-quantatively scored according to the extent of abnormally strong echo density. In nine of 11 patients undergoing MVR, a main reason for selecting MVR was a marked thickening or shortening of subvalvular structures. In patients in whom OMC was feasible, the degree of improvement of the mitral valve area (delta MVA) was assessed by the pre- and post-operative mitral valve areas (MVA) measured on the LV short-axis view, which were averaged 0.15 and 1.38 cm2, respectively. RESULTS: The index C was significantly higher in cases with MVR than those with OMC (9.2 +/- 2.6 vs 4.7 +/- 2.3 points, p less than 0.001), although there was a significant overlap between these two groups and index C did not correlate with delta MVA in the OMC patients. Similarly, the value S was significantly smaller in patients undergoing MVR than those undergoing OMC (1.2 +/- 0.4 vs 0.7 +/- 0.2 cm, p less than 0.001), though S did not correlate with delta MVA. On the other hand, the index of valve flexibility D--S was smaller in patients undergoing MVR (0.5 +/- 0.3 vs 0.8 +/- 0.3 cm, p less than 0.05) and correlated well with delta MVA (delta MVA = 0.699 x (D--S)+0.007, R = 0.678, p less than 0.02) in patients undergoing OMC. Furthermore, in all patients undergoing OMC with D--S greater than or equal to 0.8 cm, delta MVA was above 0.5 cm2, contrasting with delta MVA of 0.5 cm2 or less in 6 of 7 patients with D--S less than 0.7 cm. Using these indices, surgical procedures were successfully predicted in another 7 prospectively studied patients and predicted delta MVA in 4 patients was quite comparable with actual delta MVA. It was concluded that measurements of S and D by two-dimensional echocardiography are useful, 1) to predict patients requiring MVR and 2) to predict patients with inadequate delta MVA in whom OMC is surgically feasible.

Adult↗

Multicentric reticulohistiocytosis. Electron microscopic and ultracytochemical studies.

Lesions from a patient affected with multicentric reticulohistiocytosis (MR) were studied by ultracytochemical techniques to determine the relationship of PAS-positive materials and/or acid phosphatase (AP) activity to electron-dense granules found in the large mononucleated or multinucleated giant cells that are characteristic of this entity. The lead phosphate reaction products that mark the sites of AP activity were found in the electron-dense granules. The granules were also PAS positive by the periodic acid-thiosemicarbazide-silver proteinate method. These findings suggest that the PAS-positive and diastase-resistant materials in the large mononucleated or multinucleated giant cells of MR are not phagocytized materials but are pre-existing lysosomes.

Adult↗

Effects of truncal vagotomy on tissue gastrin content and G cell density in rats.

Tissue and serum immunoreactive gastrin (IRG) concentrations were measured by radioimmunoassay, and antral G cell density was studied by immunofluorescence in seven non-operative and ten vagotomized (one month postoperatively) rats. In the non-operative rats, tissue IRG concentration was overwhelmingly high in the antrum, especially in the distal antrum, and much less in the small intestine, in which it tended to be lower toward the distal part. There were no significant differences between the vagotomized and non-operative rats in antral G cell density, antral tissue IRG concentration, total IRG content of the anterior antrum and serum IRG level, although significantly increased wet weight of the specimen, which was considered a result of the operation, was observed in vagotomized rats. The presence of G cell hyperplasia after vagotomy cannot be confirmed from our one-month postoperative observations in rats.

Animals↗

Inhibition of development of methylnitrosourea-induced rat colon tumors by indomethacin treatment.

This study deals with the nonsteroid antiinflammatory drug indomethacin, a prostaglandin synthesis inhibitor, in the treatment of carcinogen-induced colonic tumors in rats. CD-Fischer rats were given an intrarectal instillation of methylnitrosourea (2 mg, three times a week for the first to the fifth week) in order to produce colonic tumors. Thereafter, a long-term treatment with an i.p. injection of indomethacin (2.5 mg/kg body weight, three times a week) was started at the 11th week, before the tumors developed. At autopsy, after the 15-week treatment with indomethacin, the colonic tumor incidence was significantly lower in treated rats than in vehicle-treated or untreated control rats. However, the 10-week cessation of treatment following this effective dosage led to a rapid development of tumors. In another experimental group of rats in which tumors were detected endoscopically, when treatment was initiated late, at the 26th week, for 10 weeks, tumor incidence and number were not altered. The data suggested that indomethacin inhibited the development of colonic tumors but did not reject or kill the growing tumors. It is postulated that indomethacin treatment may effectively prevent the development of colonic cancer in patients at high risk of colonic adenomatosis and carcinomatosis.

Adenocarcinoma↗

Chemoprevention of development of colonic adenomatosis and carcinomatosis with 5-fluorouracil and ftorafur on animal model.

This study deals with the treatment by chemotherapy of carcinogen-induced tumors in the colon of rats. These tumors mimic colonic adenomatosis and carcinomatosis in man. The rats were given an intrarectal (i.r.) instillation of methylnitrosourea for producing colonic tumors, and thereafter received a long-term chemotherapy which was started on nascent microscopic lesions of carcinoma. The colonic tumor incidence was significantly lower in rats treated for 10 weeks than in untreated rats. An inhibition rate of tumor development was 100% in rats with i.r. doses of 5-FU, or 57% in rats with intraperitoneal (i.p.) doses of Ftorafur. However, it was found that a few microscopic lesions of carcinoma were still present in the normal-appearing colonic mucosa, even after the completion of the effective treatment. The 10-week cessation of the treatment following the 5-week chemotherapy permitted the tumor development. The results indicate that the nascent microscopic lesions of carcinoma (premalignant lesions) in the colon can be inhibited or regulated from developing into grossly visible tumors by the effective chemotherapy, i.e., intermittent and/or long-term treatment with sensitive chemotherapeutic agents and effective way of administration.

Adenoma↗

A histopathological study on pyloric ulcer.

After the pyloric ulcer was defined as a peptic ulcer occurring at the pylorus or having its centre in the prepyloric region within 2 cm from the pylorus, its histopathological features were studied on 94 pyloric ulcers in 88 surgically resected stomachs. 72.3 per cent of these ulcers were less than 1.0 cm in diameter. The incidences of UI-II, III and IV ulcers were almost equal, and the majority of UI-II and UI-III ulcers were found in scarring stage in the specimens. These pyloric ulcers were classified into three types according to whether the centre of ulcer is situated above (Type-1), on (Type-2) or below (Type-3) the pylorus. Type-1 ulcers wre the most frequent, their incidence being 70.2 per cent. On histologic examination, it was observed that duodenal gland area extended over the pyloric antrum in 90 per cent of the specimens. Contrary to the mucosal rule of Oi for the genesis of peptic ulcer, pyloric ulcers were located in poric gland gland are in 30.9 per cent and on the glandular boundary in 57.4 per cent. Only in 11.76 per cent, the ulcer developed in duodenal gland area. In 68.2 per cent, pyloric ulcer was associated with other gastric or duodenal ulcers. The majority of these coexisting gastric ulcers occurred in the pyloric gland area adjacent to the antrofundic border, and all the duodenal ulcers in the proximal duodenum. Moderate or severe atrophic changes in gastric antral mucosa were found in a large number of the specimens with coexisting gastric ulcer, whereas the changes were less pronounced in those with pyloric ulcer alone.

Adult↗

Apocrine acrosyringeal complex in the human skin.

The acrosyringium of human apocrine sweat apparatus has been studied by light and electron microscopy using horizontal continuous serial sections. The apocrine acrosyringium is composed of 3 structurally different portions, a highly keratinizing upper portion, an incompletely keratinizing midportion, and a least keratinizing lower portion. Throughout these 3 portions, there are 2 distinctly different but closely inter-related cellular units, namely (I) a keratinization process lacking membrane-coating granules but containing keratohyalin droplets occurring in its inner cell layer, and (II) a keratinization process rich in membrane-coating granules and containing keratohyalin granules occurring in its outer surrounding concentric cell layers. In contrast to the inner cell layer, the outer cell layer does not belong to the duct proper but rather should be considered as the periacrosyringeal complex layer which is specially differentiated to envelop the intra-epithelial duct. This apocrine acrosyringeal complex in the hair follicle seems to be essentially similar to that of the eccrine apparatus in the epidermis.

Adolescent↗

G-cell populations in resected stomachs from gastric and duodenal ulcer patients.

The G-cell population in the pyloric antrum and proximal duodenum was studied quantitatively by immunofluorescence in specimens from 10 gastric and 12 duodenal ulcer patients. In both groups, G-cell density was highest in the pyloric antrum and much lower in the intermediate zone and proximal duodenum, and G-cell counts were statistically higher at the greater than the lesser curvature. The estimated total number of G cells in the whole pyloric antrum including the intermediate zone in the duodenal ulcer group was (1.806 +/- 0.347) x 10(7), this value was significantly greater (P less than 0.05) than that of (0.872 +/- 0.207) x 10(7) in the gastric ulcer group. This difference was due to a higher incidence of intestinal metaplasia and a decrease in the thickness of the antral mucosa in the latter group. The estimated total number of G cells showed a significant negative correlation not only with the patient age (P less than 0.01) but also with the degree of intestinal metaplasia of the antral mucosa (P less than 0.01) in both duodenal and gastric ulcer patients.

Adult↗

Ultracytochemical study on eccrine acrosyringium of human embryos. Acid phosphatase activity during formation of lumen.

Ultracytochemical demonstration of acid phosphatase (ACPase) activity during the developing of intraepidermal eccrine sweat duct (eccrine acrosyringium) of human embryos was performed in order to elucidate the functional relationship between multivesicular dense bodies and intracellular cavities formed within the inner cells of eccrine sweat apparatus anlagen and to clarify the ultracytochemical characteristics of the multivesicular dense bodies. ACPase activity was characteristically detected in the unit membrane structures of small pinched-off vesicles within cavities and of immature microvilli lining these cavities as well as in those of multivesicular dense bodies. These findings give strong support to the theory that the multivesicular dense bodies are lysosomes and through their action the autolytic formation of intraepidermal eccrine sweat duct is carried out.

Acid Phosphatase↗

G-cell population in antral mucosa of the dog.

The gastrin-cell (G-cell) population in the pyloric antrum of 8 dogs was studied quantitatively by immunofluorescence. The G-cell population was dense in the pyloric antrum and very few cells were seen in the antrocorporal junction. The estimated total number of G cells was (1.66 +/- 0.12) X 10(7) in the pyloric antrum and the greatest number of G cells per unit mucosal surface area was along the greater curvature of the pyloric antrum. Except along the greater curvature, G cells per unit musocal volume were significantly greater in number (P less than 0.05) in the proximal antrum adjacent to the antrocorporal junction that in any other regions distal to it. Differences in mucosal thickness were considered as a causative factor for these differences.

Animals↗

Gastric response to meat extract stimulation in patients with gastroduodenal ulcer and patients after vagotomy or antrectomy.

Gastric acid secretion basally and in response to intragastric meat extract instillation or to tetragastrin, and circulating gastrin concentration basally and after meat extract stimulation were studied in 67 patients with gastroduodenal ulcer, 30 patients after highly selective vagotomy or selective vagotomy for duodenal ulcer, 12 patients after antrectomy for or gastric ulcer and 10 control subjects. Circulating gastrin concentration increased significantly after meat extract stimulation in control subjects, patients with ulceration and patients after highly selective vagotomy, and acid secretion in each group was increased significantly above basal level. In patients after selective vagotomy, significant increase of circulating gastrin concentration was observed, but it was not associated with significant increase of acid secretion. After antrectomy, neither gastrin nor acid secretion increased significantly after meat extract stimulation. In conclusion, present study suggested that (1) gastric acid secretion in response to intragastric meat extract is chiefly affected by the responsiveness of oxyntic cells and release of antral gastrin and that (2) the presence of the antrum is almost essential for acid secretion after a test meal, and release of duodenal gastrin after antrectomy would not be so potent biologically as to result in an acid secretion.

Adult↗

Inhibition of gastric secretion by intraduodenal hypertonic glucose in patients with duodenal ulcer.

Intraduodenal instillation of hypertonic glucose significantly inhibited tetragastrin-induced gastric acid and pepsin outputs in man. The secretory volume of gastric juice was markedly decreased, whereas, acid concentration remained unchanged. Pepsin concentration, on the contrary, was reduced significantly. The degree of inhibition of pepsin output, therefore, was greater than that of acid output. No significant difference in the extent of inhibition of acid or pepsin output was observed between control subjects and patients with duodenal ulcer.

Adult↗

[Effect of synthetic motilin on gastric motility (author's transl)].

The effects of the synthetic motilin on the gastric motility were investigated in the dogs with innervated antral pouches in fasting state. The results were as follows: 1) The synthetic motilin stimulated markedly the gastric motor activity in both the contraction pressure and the frequency of the peristalsis. 2) Tetragastrin produced more regular and higher frequent contractions compared with synthetic motilin, but acted to weaker the contraction pressure. 3) In simultaneous administration of the synthetic motilin and the tetragastrin, the synthetic motilin acted more strongly in the contraction pressure, on the other hand tetragastrin in the frequency of the peristalsis. 4) The peristaltic contractions induced by synthetic motilin were completely abolished by the administration of the atropine sulfate. 5) Under medical vagotomy, synthetic motilin was not able to produce any peristatlic contractions, but tetragastrin stimulated strongly the gastric motility.

Animals↗