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Biomedical subjects

N Azuma

Publications and source records attributed to N Azuma.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Recent advances and problems in peripheral arterial reconstruction].

Recent advances in the field of peripheral arterial reconstruction have been remarkable. These advances are mainly derived from the development of diagnostic technology such as Doppler ultrasound analysis, further refinement of surgical technique including surgical instruments and materials, and naturally improvement of patient care in the pre-, peri- and postoperative period. During the past 14 years we have performed peripheral arterial reconstruction in 1,200 cases (1,660 limbs) mainly with occlusive lesion due to arteriosclerosis obliterans. In our hand, aorto-iliac occlusive lesion has been routinely bypassed with Dacron prostheses and the secondary patency rate at eleven years reached 96.5%. The main problems encountered in this region were anastomotic aneurysm in the femoral artery (3.9%) and graft infection (1.2%). In the infrainguinal region there are still problems to be solved, although the primary (secondary) 5 year patency rates of reversed vein graft as well as in situ vein graft including femoro-popliteal below knee and femoro-crural bypasses have exceeded 70% (85%). First, there is no graft material comparable to the autogenous vein (AVG). Secondly, many of the AVG should suffer occlusive pathological changes from the environment in the long term following surgery. At the present time, we have no effective method to solve these problems, therefore we should follow up the patients heedfully to maintain the graft patency as well as to improve their quality of life and prognosis.

Anastomosis, Surgical↗
PubMed1994

["Extended aortic arch anastomosis" in Shone's anomaly--a case report].

We report a case of a newborn with Shone's anomaly in whom the parachute mitral valve, mild subaortic stenosis, hypoplastic aortic arch, and severe coarctation of the aorta were found. The patient was 10 days old, who had symptoms of low output syndrome due to the progressive obstruction of patent ductus arteriosus, underwent "extended aortic arch anastomosis" to repair the hypoplastic aortic arch and severe coarctation of the aorta. This surgical procedure, resulting in a successful post-operative course of the patient, might be effective in such anomalies.

Anastomosis, Surgical↗
PubMed1993

A new treatment for dialysis-related amyloidosis with beta 2-microglobulin adsorbent column.

Dialysis-related amyloidosis (DRA) is characterized by the presence of beta 2-microglobulin (beta 2-m) in the plasma. In order to eliminate beta 2-m from the circulating blood, the beta 2-m selective adsorbent for direct hemoperfusion (DHP) was developed. A DHP column (BM-01), containing 350 ml of the adsorbent, was subjected to clinical trials. The column was connected with a PAN (AN69) membrane dialyzer in series and used 3 times a week for 1 week (11 patients), 4 weeks (5 patients), 6 months (1 patient) and 12 months (2 patients). The percent reduction (%) of beta 2-m was for 16 patients (for 1 or 4 weeks), more than 65, and for 3 patients (for more than 6 months), 76.5 +/- 4.9, 73.5 +/- 5.7, 72.2 +/- 6.2. At the end of each session, beta 2-m plasma levels were found to be below 10 mg/L, with 3.4 mg/L being the lowest. The total amounts of beta 2-m removed were 172.5 +/- 22.3, 257.0 +/- 75.6, 157.6 +/- 32.2 and 429.8 mg/session at max. Two out of these three patients had a favorable effect on joint symptoms and ocular fundus. It can be concluded that this selective adsorption therapy may delay the progression of DRA, and is worth considering for wide application.

Adsorption↗
PubMed1993

[Histochemical and electron microscopic study of the formation of trabecular meshwork and changes of glycosaminoglycans].

The development of iridocorneal angle and trabecular tissue was investigated histochemically and electron microscopically. Sixty-three human eyes at from 5 to 22 weeks of gestation were used in this study. For identifying glycosaminoglycans, alcian blue staining and enzyme digestion methods with hyaluronidase and chondroitinase AC and ABC were carried out light microscopically. Electron microscopically, specimens were stained with ruthenium red. In the early stage from 8 to 10 weeks, mesenchymal cells between the primordium of the cornea and the iris became elongated and connected with one another. Desmosome-like junctional complexes were observed in these cells. Schlemm's canal and para-canalicular tissue were observed at 20 weeks and the structure of the meshwork became similar that of adults. From findings of enzyme digestion methods, glycosaminoglycans in trabecular tissue seemed to be mainly hyaluronic acid in the early stage, which was replaced by chondroitin sulfate and dermatan sulfate afterwards. Substances positive for ruthenium red, which seemed to be glycosaminoglycans, was observed in intercellular spaces electron microscopically. They decreased according to development. These findings indicated that the beginning of aqueous outflow might be related to the decrease of glycosaminoglycans in trabecular tissue.

Gestational Age↗
PubMed1993

[Extensive bowel infarction caused by intraaortic balloon pumping].

Two cases of an extensive bowel infarction occurred during Intraaortic Balloon Pumping (IABP) are reported. In the first, an acute myocardial infarction was seen suddenly on the seventh postoperative day following arterial reconstruction of the right lower leg and his condition required IABP support. Five day after beginning of IABP, severe symptoms suggesting peritonitis appeared, and laparotomy revealed an extensive infarction of small bowel and sigmoid colon. In the second, the patient required IABP support for weaning from cardiopulmonary bypass after completion of coronary artery bypass grafting. A severe peritonitis was caused by an extensive infarction of small and large intestine during two days of IABP support. Cholesterol emboli were found in the small bowel arteries of the case 1 at microscopic examinations of the autopsy specimen. Both patients died of cardiopulmonary failure and renal failure respectively, though necrotic intestine were resected. Circulatory support using IABP should not be selected, when a patient has severe arteriosclerotic lesions of the aorta.

Angina, Unstable↗
PubMed1992

Morphological studies on cataract and small lens formation in neonatal rats treated with monosodium-L-glutamate.

Changes in the transparency and size of lenses in rats were investigated following administration of monosodium-L-glutamate (MSG). MSG (5 mg/g b.w.) was injected subcutaneously on the 9th and 10th day after birth. Ophthalmoscopically, localized opacity was apparent at the posterior pole of the lens corresponding to the attached site of the hyaloid vessels at the 1-month stage. The incidence of cataract increased with age, reaching more than 75% at 4 months. Morgagnian globules were histologically detected in the opacity of the posterior lens cortex. The size and weight of the lens were smaller than those of the control rats. These findings indicate that the administration of MSG could be an etiologic factor in cataract formation in the developing rat.

Animals↗
PubMed1992

Localization of elastic fibers and elastin mRNA in the uvea of chick embryo.

The distribution of elastic fibers and elastin mRNA was studied in the uvea of 19-day-old chick embryos by light and electron microscopy and in situ hybridization techniques using a 35S-labeled RNA probe. Light and electron microscopic examination revealed that elastic fibers were present in the uveal portion of the ciliary body, but not in the posterior choroid. Electron microscopically, elastic fibers were also found in Bruch's membrane. Abundant amounts of elastin mRNA were strictly localized in the fibroblasts in the uveal portion of the ciliary body, and no elastin mRNA was found in any of the cells in the posterior choroid by in situ hybridization. Cultured uveal tissue obtained from the ciliary body was found to produce large amounts of tropoelastin as compared with cultured posterior choroid. Using V8 protease peptide mapping and Northern blot analysis, the tropoelastin and its mRNA produced by the ciliary body were identical to those produced by the smooth muscle cells in the aorta. The results suggest that elastin is synthesized in the ciliary body, acting as a supporting substance in this area.

Animals↗
PubMed1992

[Scanning and transmission electron microscopic studies of the ultrastructure of the corneal endothelium in developing human eye].

The ultra-microstructure of the human corneal endothelium was examined by scanning and transmission electron microscopy. The samples were corneas of 26 human eyes taken from fetuses of 5-22 weeks gestation and a newborn 10 months after birth. Corneal endothelium appeared at the seventh or eighth week after gestation. Initially, they formed an irregular structure of two to three layers. From the 17th week of gestation they formed a single layer, and assumed the form of a cuboidal epithelium. Scanning and transmission electron microscopy showed numerous microvilli protruding towards the anterior chamber. Within the microvilli uniform microtubules were observed. By the 20th week, these microvilli disappeared, and subsequently, a single long narrow cilium appeared in the center of each cell. Each cilium had an axial filament complex structure. This cilium involuted as development progressed, and was barely visible by the 10th month after birth. The significance of this cilium is not clear.

Endothelium, Corneal↗
PubMed1992

Morphological and histochemical studies of goblet cells in developing human conjunctiva.

This study deals with the development of the human conjunctival goblet cells. Fifty-six eyes of human embryos and fetuses ranging from 5 to 41 weeks of gestational stage were used. The distribution of glycosaminoglycans in the goblet cells was investigated with 1% alcian blue (pH 2.5) staining. For identifying the types of glycosaminoglycans, enzyme digestion methods were carried out with streptomyces hyaluronidase, chondroitinase AC, chondroitinase ABC, or sialidase (neuraminidase). At 9 weeks of gestational age, goblet cells appeared in the fornix region of the conjunctiva and extended toward the palpebral and bulbar regions. Histochemical studies with enzyme digestion methods revealed the existence of sialomucin in the goblet cells from 9 weeks. This finding suggested that the goblet cells first appeared in the fornix area, extending toward the palpebral region, then toward the bulbar region, and containing sialomucin from their early stage of development.

Chondroitin Lyases↗
PubMed1992

Anterior capsular opacification after endocapsular cataract surgery.

The central parts of the opacified anterior capsules of nine eyes of nine patients after endocapsular phacoemulsification followed by posterior chamber intraocular lens implantation were removed after an average postoperative period of 25 months and examined by light and electron microscopy. The opacified materials were judged to be collagen. Transmission electron microscopy revealed fibers 50 to 60 nm in diameter, with approximately 65-nanometer periodic bands in five of the nine eyes. Most remaining cells showed multilayered proliferation and were rich in cytoplasmic microtubules and surface dendrites. These results indicate that postoperative anterior capsular opacification is composed of fibroblast-like cells, presumably transformed from lens epithelial cells and collagen.

Aged↗
PubMed1991

Identification of alpha-lactalbumin and beta-lactoglobulin in cynomolgus monkey (Macaca fascicularis) milk.

1. An electrophoretic analysis of whey protein from cynomolgus monkey milk revealed that its constituents are more similar to bovine milk than human milk, i.e. cynomolgus monkey milk whey contains, besides alpha-lactalbumin-like protein (LaP), another predominant component similar to bovine beta-lactoglobulin (LgP), in its electrophoretic behavior on both disc- and SDS-polyacrylamide gel electrophoreses. 2. The amino acid composition of LaP shows close similarity to that of human alpha-lactalbumin, and LaP forms an immunoprecipitin line with anti-human alpha-lactalbumin rabbit antiserum. The homology between LaP and alpha-lactalbumin was further confirmed by an analysis of the N-terminal amino acid sequence. 3. LgP is not immunologically identical to bovine beta-lactoglobulin, but its amino acid composition is similar. The result of the N-terminal amino acid sequence analysis of LgP (up to the 26th residue) strongly suggests homology between this protein and beta-lactoglobulin.

Amino Acid Sequence↗
PubMed1991

Enzymic modification of alpha s1-casein with peptidylarginine deiminase: preparation of less acid-coagulable and less calcium-sensitive casein.

Enzymic modification with peptidylarginine deiminase (EC 3.5.3.15) enabled five out of six arginyl residues in alpha s1-casein to be converted to citrullyl residues, only the N-terminal arginyl residue remaining unaffected. An increase in the net negative charge was confirmed by PAGE. The isoelectric point was decreased from 4.46 for the intact alpha s1-casein to 4.30 for the deiminated type, while simultaneously lowering the acid-precipitation starting point from pH 5.17 to pH 4.62. The deiminated alpha s1-casein self-associated less in the absence of Ca and was less Ca-sensitive than the native type, although its Ca-binding ability was slightly enhanced. In the presence of 25 mM-CaCl2 and kappa-casein, Ca-induced precipitation of alpha s1-casein did not occur, the solution of the mixture remaining transparent. Deimination of alpha s1-casein resulted in altering its characteristics, possibly by interfering with interactions through hydrophobicity and/or hydrogen bonding. The positive charge of the arginyl residues might play an important role in casein micelle formation.

Amino Acids↗
PubMed1991

Increased concentrations of free light chain lambda in sera from chronic hemodialysis patients.

Serum levels of FLc were determined in 5 pre-HD CRF patients, 63 CRF patients receiving HD therapy, 15 CAPD and 40 healthy volunteers. The highest serum FLc concentration was observed in patients receiving HD. Concentrations of kappa- and lambda FLc were higher than normal in patients with CRF, and were about 4-fold and 1.8 fold greater than control values in HD patients, with a predominance of lambda chains. This HD-associated elevation of serum FLc strongly suggests a role for FLc in the etiology of light chain deposit disease and AL-amyloidosis. Lambda-FLc and beta 2-m exhibited similar patterns of change in the serum during the course of HD therapy. Further studies may reveal other pathological conditions other than CRF in which these polypeptides may play a role.

Carpal Tunnel Syndrome↗