Biomedical subjects

H Miwa

Publications and source records attributed to H Miwa.

353 records · Page 20Linked to original sources

PubMedDate not supplied

Diagnosis of gastric adenoma versus early gastric cancer by bromodeoxyuridine immunohistochemistry from gastric biopsy specimen.

Differentiation between gastric adenomas and type IIa early gastric cancer by macroscopic and histologic examinations is often difficult. This study has shown that there are differences in the distribution of S-phase cells in these two types of tumour, and these differences can be exploited to differentiate between them. The distribution of S-phase cells was assessed by Bromodeoxyuridine (BrdU) immunohistochemistry using an in vitro BrdU-labelling method. Biopsy specimens were obtained from 27 lesions (12 adenomas and 15 type IIa early gastric cancers), and the distributions of BrdU-labelled cells in the tumour thickness as well as in the superficial layer of the tumour were determined. Significant difference was seen in the labelling of the two tumour types with regard to both these parameters. Using the criteria of BrdU immunohistochemistry, the accuracy of differentiation between gastric adenomas and cancers was 88.9%. Therefore, it is concluded in this study that in vitro BrdU labelling is a useful method of diagnosing gastric adenomas and cancers.

Adenoma↗

PubMedDate not supplied

Phenotypic reversion of smooth muscle cells in hybrid vascular prostheses.

Our purpose was to evaluate whether or not and when phenotypic modulation of smooth muscle cells (SMCs) in hybrid vascular prostheses preincorporated with SMCs occurs upon implantation. Two types of hybrid vascular grafts incorporated with vascular cells derived from canine jugular veins were prepared: grafts containing a collagen gel layer covered with an endothelial monolayer at the luminal surface (Model I graft) and those containing an endothelial monolayer and SMC multilayer (Model II graft). They were bilaterally implanted into carotid arteries of the same dogs from which the cells had been harvested for 2 wk (n = 3) and 12 wk (n = 3). The time-dependent changes in populations of three SMC phenotypes (synthetic, intermediate, and contractile) in the neoarterial layers were quantified by morphometric evaluation using a transmission electron microscope in hybrid vascular grafts. Before implantation, all the SMCs were of the synthetic phenotype. In Model II grafts at 2 wk, synthetic and intermediate SMCs were dominant especially in the luminal layer. On the other hand, neoarterial layers at 12 wk were dominated by contractile SMCs, which were evenly distributed throughout the entire neoarterial tissues. A markedly delayed phenotypic reversion was noted for the Model I grafts at 12 wk. In the hybrid grafts, during about 3 mo of implantation, neoarterial SMCs transformed from the synthetic to the contractile phenotypes, which was promoted by SMC incorporation.

Animals↗

PubMedDate not supplied

Isolation of tumor associated antigens from Lewis lung carcinoma by affinity chromatography on peanut agglutinin-agarose.

Receptors for peanut agglutinin (PNA) were isolated from Lewis lung carcinoma cells (3LL) by detergent solubilization and affinity chromatography on PNA-agarose. The isolated receptors showed heterogeneous yet distinct molecular species when they were analyzed by SDS gel electrophoresis. In vivo inoculation of the isolated receptors could induce potent cytotoxic effector cells against 3LL cells, which were detected by Winn's tumor neutralization assay. The PNA receptors were also effective in preventing the settlement of the intravenously injected 3LL tumors in the lung. These findings suggest that PNA receptors can be used for immunological therapy of certain cancers.

Animals↗

PubMedDate not supplied

Psammoma bodies found in cervicovaginal and/or endometrial smears.

Eight cases of the unusual occurrence of psammoma bodies associated with adenocarcinoma cells in cervicovaginal and/or endometrial smears are presented. Three of the eight cases were advanced ovarian cancers, four were primary endometrial adenocarcinomas, and one was a metastasis of breast cancer to the pouch of Douglas. From our histologic and histochemical observations, psammoma bodies seem to be secretory rather than degenerative in origin.

Adult↗

PubMedDate not supplied

[Left atrial function during left ventricular diastole evaluated by left atrial angiography and left ventriculography].

The left atrium (LA) stores part of the right ventricular stroke volume during ventricular systole for passive release into the left ventricle (LV) during ventricular early diastole and active release during ventricular late diastole (passive and active contraction). The rest of the right ventricular stroke volume flows through the LA from the pulmonary vascular bed to the LV (LA conduit function). The factors affecting these LA functions were evaluated during ventricular diastole by left atrial angiography and left ventriculography in 21 patients with normal LV ejection fraction (0.53-0.76), but without coronary artery disease and valvular heart disease, aged 40-70 years. LV stroke volume was calculated from left ventriculograms. The maximal LA volume, minimal LA volume, and LA volume at the beginning of the left atrial active contraction were calculated from the left atrial angiograms, and further corrected by a regression equation (true volume = 0.91 x calculated volume -1.1). The LA reservoir volume, LA passive contraction volume, LA active contraction volume, and LA conduit volume were obtained. LA conduit volume correlated significantly with LV stroke volume (r = 0.97), but not with maximal LA volume and LA reservoir volume. LA active contraction volume correlated significantly with LA reservoir volume, LA volume at the beginning of LA active contraction, and maximal LA volume (r = 0.85, 0.60, 0.54, respectively). LA passive contraction volume did not correlate with any factor, and was grossly independent of LV stroke volume. LA conduit volume may be associated with LV diastolic function, and LA active contraction volume appears to increase with increased LA volume.

Adult↗

PubMedDate not supplied

Development of a hierarchically structured hybrid vascular graft biomimicking natural arteries.

A hierarchically structured hybrid vascular graft, resembling the layered structure of the intima and the media of a natural artery, is expected to exhibit structural stability and function similar to those of an artery. Two models of hybrid vascular grafts were constructed on knitted Dacron grafts (internal diameter, 4 mm; length, 6 cm; Golaski Laboratories, Inc., Philadelphia, PA) in vitro. The model I graft consisted of only an endothelial cell (EC) monolayer, and the model II graft was hierarchically structured with an EC monolayer and smooth muscle cell (SMC) multilayers embedded in a mixed gel of type I collagen and dermatan sulfate. Both models were implanted bilaterally in carotid arteries of 11 dogs for up to 12 weeks without anticoagulant. All grafts were patent after the implantation. There was a marked difference in the formation of the neomedia between the two models at 2 weeks: only a collagenous layer was observed beneath the EC monolayer in model I grafts, whereas the reconstructed neomedia consisting of proliferating SMCs and extracellular matrix was observed in model II grafts. In model I grafts at 2 weeks, the luminal surface with a wavelike form, along with crimps of the vascular graft, was almost endothelialized, but EC orientation was disorganized at the troughs of the crimps. Leukocyte adhesion on ECs and migration into their interstices were observed in some areas. Such events were infrequent in model II grafts at 2 weeks. Model II grafts at 12 weeks had an integrated neomedia comparable to that of a natural artery: SMCs exhibited dense accumulation and circumferential orientation.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗

PubMedDate not supplied

Phenotypic modulation of smooth muscle cells in intima-media incorporated hybrid vascular prostheses.

Hierarchical hybrid vascular grafts were constructed with an endothelial cell (EC) monolayer and hybrid medial layer composed of smooth muscle cells (SMCs) and type I collagen gel. The grafts, implanted into canine carotid arteries for up to 12 weeks, were ultrastructurally examined with a transmission electron microscope. Before implantation, SMCs incorporated into hybrid media were round and intracellularly filled with synthetic organelles such as rough endoplasmic reticula, mitochondria, free ribosomes, and Golgi complexes. Two weeks after implantation, bipolar spindle shaped SMCs still remained in a synthetic phenotype. At 12 weeks, circumferentially aligned SMCs were abundant in contractile apparatus such as myofilaments, dense bodies, and basement membranes. In a morphometric evaluation, the populations of three phenotypic SMCs (synthetic, intermediate, and contractile SMCs) were quantified. At 2 weeks, the proportions were 50.5, 41.8, and 7.7% for synthetic, intermediate, and contractile phenotypes, respectively. At 12 weeks, they were 9.9, 26.2, and 63.8%. These findings indicated that SMCs incorporated into hybrid grafts were transformed from a synthetic to a contractile phenotype under pulsatile stressed conditions after 12 weeks in vivo. Thus, the intima/media incorporated hybrid graft reconstructed a vessel wall similar to a native one in terms of structure and function.

Animals↗

PubMedDate not supplied

Newly designed tissue adhesion prevention technology based on photocurable mucopolysaccharides. In vivo evaluation.

Tissue adhesion after surgery occasionally causes serious complications. The authors have been developing photocurable mucopolysaccharides for a tissue adhesion prevention material that meets requirements such as nonadherent surface characteristics, biocompatibility, biodegradability in accordance with the wound healing rate, and nontoxicity. Mucopolysaccharides (hyaluronic acid and chondroitin sulfate) partially derived with photoreactive groups, such as cinnamate or thymine, were subjected to ultraviolet (UV) irradiation to produce water insoluble gels via intermolecular photodimerization of photoreactive groups. Photocured films that covered injured liver surfaces of rats were implanted for as long as 4 weeks and histologically evaluated. In vivo performance, including tissue adhesion prevention, biodegradability, and mechanical flexibility of the films, was found to be controlled by the type of mucopolysaccharides, the type of photoreactive groups, and their degrees of substitution (DS). Photocured films with lower DS, which had high water swellability and flexibility, prevented tissue adhesion and exhibited enhanced biodegradability. As an increase in DS occurred, tissue adhesion prevention, biodegradability, and mechanical flexibility were reduced. Control of the biodegradation rate was feasible. Minimum inflammatory reaction was noticed.

Animals↗

PubMedDate not supplied

An in vitro endothelialized compliant vascular graft minimizes anastomotic hyperplasia.

The authors developed a hybrid vascular graft consisting of three components: a polyurethane (PU) graft (internal diameter = 3 mm; length: 5 cm) with a compliance similar to that of natural arteries; an artificial basement membrane composed of a complex gel of Type I collagen and dermatan sulfate; and an autogenous endothelial cell (EC) monolayer constructed before implantation. As a continuation of their previous study that focused on antithrombogenicity for as long as 1 month after implantation, the authors evaluated the antihyperplastic characteristics of their hybrid vascular graft for longer implantation periods. The hybrid grafts were implanted bilaterally into carotid arteries of dogs without anticoagulant or anti-platelet agents. The implantation period ranged from 6 to 26 weeks. The overall patency rate observed in this study was 70%. Histologic evaluation of grafts revealed that luminal surfaces of the arteries and grafts joined uniformly and smoothly. The mean initimal thickness of grafts was approximately 80 microns at 12 weeks; there was no statistically significant difference in the thickness between portions of the graft. Little additional increase was observed at 26 weeks. The intimal thickness of adjacent arteries was small. Thus, anastomotic hyperplasia was considered minimized. These encouraging results were explained in terms of synergistic activities of the compliant PU graft and durable EC monolayer as follows. The PU graft, which was fabricated to have the same compliance as that of natural arteries, minimized the compliance mismatch at the anastomoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

PubMedDate not supplied

Fluorometric determination of total and bound sulfite in wine by N-(9-acridinyl)maleimide.

N-(9-Acridinyl)maleimide (NAM) reacts with sulfite in wine and gives strong fluorescent derivatives that lead to highly sensitive fluorometry of both total and bound sulfite in wine. Values of free and bound sulfite in wine determined by the NAM method and the modified Rankine method agreed. Sulfite was determined in < 200 microL wine within 2 h.

Fluorometry↗

PubMedDate not supplied

Rapid liquid chromatographic determination of fatty acids as 2-nitrophenylhydrazine derivatives.

Direct derivatization of saponified fats and oils with 2-nitrophenylhydrazine hydrochloride produced corresponding fatty acid hydrazides without time-consuming sample cleanup and/or extraction steps. Hydrazides were injected directly into a liquid chromatograph. Improved isocratic separation was achieved within only 22 min for 29 saturated and mono- and polyunsaturated fatty acids (C8:0-C22:6), including cis-trans isomers and double-bond positional isomers. The technique has good quantitative accuracy while reducing analysis time, cost, and labor.

Chromatography, Liquid↗