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Biomedical subjects

H Yano

Publications and source records attributed to H Yano.

At least 307 records · Page 17Linked to original sources
PubMed1994

Effects of insulin on in vitro bone formation in fetal rat parietal bone.

We examined the effects of insulin on bone formation including the mineralizing process. Twenty-day fetal rat parietal bones were cultured for 96 h on grids in a serum-free medium. For the precise assessment of bone formation, histomorphometry, with an image analyzing system, was used to measure the areas of mineralized bone and bone matrix, and the numbers of osteoblasts and osteoclasts. In order to confirm the effects of insulin on bone mineralization, the calcium content of the bone and the release of previously incorporated 45Ca into the medium were measured. Insulin, at a concentration of 10(-6) M or higher, increased the areas of mineralized bone and bone matrix, and the number of osteoblasts. Osteoclasts were seldom observed in bones on day 0 or in bones treated with insulin. In bones treated with insulin at a concentration of 10(-6) M, the calcium content of bone increased. At an insulin concentration of 10(-7) M or higher, the dry weight of decalcified bone increased. Lactate production in the medium increased dose-dependently. The inhibited release of 45Ca in bones indicated that insulin acts by increasing calcium retention. We demonstrated that insulin has an effect on bone-forming and bone-resorbing cells to enhance the bone forming process from matrix formation to mineralization.

Animals↗
PubMed1994

Hind III site causing Proinsulin Kyoto and Pst I site polymorphism of the insulin gene in Japanese: its lack of association with either IDDM or NIDDM.

The gene encoding Proinsulin Kyoto has been isolated and characterized by DNA sequencing, indicating that the molecular basis of the disorder is a G-T point mutation in the insulin gene which creates a Hind III site. In addition, in the 3'-untranslated region of the mutant insulin gene, a Pst I site negative, alpha type allele was found, and in the normal gene, a Pst I site positive, beta type allele was found. In order to clarify the frequency of the mutation and to determine whether this mutation is associated with diabetes mellitus or not, we have investigated Hind III polymorphism in 91 normal Japanese subjects and patients with IDDM and NIDDM. No cases with the Proinsulin Kyoto gene were found among the subjects examined. Secondly, to determine whether this alpha type allele is associated with DM in Japanese, we investigated Pst I polymorphism in the same subjects. The frequencies of the alpha type and beta type alleles were 92% and 8%, respectively. No significant difference in genotypic frequency was found among normal, NIDDM, and IDDM. We conclude that the Proinsulin Kyoto gene is not a common cause of DM and the occurrence of the alpha type insulin gene in Japanese diabetes is more frequent than in other races, so this Pst I polymorphism is not a marker for diabetes mellitus in Japanese.

Base Sequence↗
PubMed1994

Symptomatic middle cerebral artery stenosis and occlusion: comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography.

The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (< 1.0 cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients.

Adult↗
PubMed1994

The influences of casein phosphopeptides on metabolism of ectopic bone induced by decalcified bone matrix implantation in rats.

The effect of casein phosphopeptides (CPP) on bone metabolism was studied in the ectopic bone induced by the implantation of decalcified bone matrix in rats. Forty-two Wistar male rats of 7 weeks old were fed low calcium diets (0.39% of calcium) with or without supplying 0.50% of CPP, or a control diet (0.91% of calcium) without CPP supplementation. After a 1-week preliminary period, each rat was subcutaneously implanted with 30 mg of demineralized bone matrix powder. Fourteen and 21 days after the implantation, the implants were harvested from 7 rats of each group. Calcium content in the graft was not significantly different among all groups on day 14. Subsequently, the content of calcium rapidly increased in the grafts irrespective of diets given. However, the graft of the CPP- group contained less calcium than the other groups and the calcium content was more in the control rats compared to the CPP+ animals on day 21. Alkaline phosphatase activity (an index of bone and cartilage calcification) was lower in the control group than in the CPP+ group on day 14. The enzyme activity subsequently decreased in the control group but the activity was not changed in the other groups. As a result, the activity of alkaline phosphatase was lower in the control animals than in the other rats on day 21. Tartrate-resistant cap phosphatase activity (an index of bone resorption) was higher in the CPP--group compared to the control on day 14. On day 21, the activity was higher in the CPP--group compared to the others.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1994

[Study of bone formation in fetal rat parietal bone using serum-free bone-forming organ culture system: effect of insulin on bone formation].

Serum-free bone-forming organ culture system using twenty-day fetal rat parietal bones was established. The effects of insulin on bone formation were studied in this system. Bones were cultured on grids and placed on a rocking platform under an aerobic condition. This condition increased the bone-forming activities of cultured rat parietal bones. The calcium content, dry weight of bone, and lactate produced by bone tissue in the medium were measured to study the precise bone-forming process of vital bones. Using this improved bone-forming organ culture system, insulin increased calcium content and dry weight of bone. These effects were maximum in bones treated with insulin at 10(-6) M. Histo-morphometrical analysis showed that the areas of mineralized bone and bone matrix increased, and that many osteoblasts and few osteoclasts appeared in bones treated with insulin at 10(-6) M or higher. Insulin inhibited the release of 45Ca into the medium. From these results, it was suggested that insulin has a stimulatory effect on bone formation, enhancing both bone mineralization and bone matrix formation.

Animals↗
PubMed1994

Ultrastructural localization of intranucleolar DNA in Vicia faba root-tip cells by immunocytochemistry using an anti-BUdR antibody.

Ultrastructural localization of intranucleolar DNA in Vicia faba root-tip cells was investigated by an immunocytochemical method consisting of in vitro bromodeoxyuridine (BUdR)-labelling with the aid of terminal deoxynucleotidyltransferase and successive immunocytochemistry using an anti-BUdR antibody. The nucleolus usually had many low electron-opaque patches (LEPs). The fibrillar centers (FCs) occupied their peripheral region leaving a central electron-transparent space (central space). The immunoelectron microscopic technique showed that in the nucleolus the label was mostly confined to the FCs whilst the central space was completely free from the label. In other nucleolar regions the label appeared to gradually increase towards the FCs. In addition to nucleoli, this method also localized a small amount of DNA in mitochondria.

Bromodeoxyuridine↗
PubMed1994

[Qualitative evaluation of 123I-IMP SPECT using a rotating gamma camera in atherosclerotic large-artery disease].

PURPOSE Quantitative measurement of regional cerebral blood flow (rCBF) needs special equipment or invasive blood sampling. Therefore, with a popularly used rotating gamma camera, we tried to establish a convenient modality of qualitative evaluation of hemodynamics in patients with atherosclerotic large-artery disease, according to the distribution pattern of isotope-uptake on SPECT image. PATIENTS AND METHODS Forty-one patients with atherosclerotic large-artery disease [9 internal carotid artery (ICA) stenosis, 17 ICA occlusion, 8 middle cerebral artery (MCA) stenosis, and 7 MCA occlusion] and 32 control patients documented as having small cerebral infarction without atherosclerotic large-artery disease were investigated. Using the rotating gamma camera, they underwent 123I-IMP SPECT at baseline and after acetazolamide loading. According to the distribution pattern of low isotope-uptake, early images were classified into four types: Type I: no low uptake, Type II: low uptake in a single watershed, Type III: low uptake in two watersheds with or without a partial MCA territory, Type IV: low uptake in a whole MCA territory. RESULT In patients with large-artery disease, baseline images presented Type I in 12 cases, Type II in 16, Type III in 9, Type IV in 4, and loading images Type I in 3, Type II in 2, Type III in 8, Type IV in 28. Of 37 patients except for 4 belonging to Type IV at baseline, 32 (86.5%) had a more extensive low isotope-uptake area after acetazolamide loading than at baseline. In control patients, baseline images presented Type I in 25, Type II in 7, and the Type III & IV in 0, and the Type after loading was the same as the Type at baseline. CONCLUSION We established the qualitative evaluation of 123I-IMP SPECT image by detecting the "extent" of the ischemic region, taking notice of watershed. The pathognomonic findings on SPECT image of atherosclerotic large-artery disease showed that low isotope-uptake area at baseline extended into two watersheds or MCA territory by acetazolamide loading. The modality of qualitative evaluation based on these pathognomic findings of SPECT image may be useful for easily assessing patients with atherosclerotic large-artery disease using a rotating gamma camera.

Adult↗
PubMed1994

Alternative splicing of human inwardly rectifying K+ channel ROMK1 mRNA.

Recent studies have identified a new family of inwardly rectifying K+ channels, members of which are known by the acronyms ROMK1, IRK1, and GIRK1. We have isolated cDNAs encoding the human homologue of ROMK1 from an adult kidney cDNA library. The sequences of the human kidney ROMK1 cDNA clones indicated that they were derived from at least two types of mRNAs, human ROMK1A and human ROMK1B, differing in sequence at their 5' ends. The isolation of the human ROMK1 gene, localized to chromosome band 11q24 by fluorescence in situ hybridization, indicated that the different ROMK1 transcripts were generated by alternative splicing. Human ROMK1A mRNA was predicted to encode a protein of 389 amino acids, having 93% identity with the 391-residue rat ROMK1 protein, and expression studies in Xenopus oocytes indicated that it encoded a Ba(2+)-sensitive inwardly rectifying K+ channel with properties similar to those reported for cloned rat ROMK1. Human ROMK1B mRNA was predicted to encode a protein of 372 amino acids whose sequence was truncated at the amino terminus but otherwise identical to that of the human ROMK1A protein. Translation of human ROMK1B mRNA was predicted to initiate at a codon corresponding to Met-18 of human ROMK1A mRNA. Reverse transcriptase-polymerase chain reaction amplification of human kidney mRNA revealed human ROMK1A and -B transcripts as well as a third type of transcript, human ROMK1C mRNA, which was predicted to encode a protein identical to human ROMK1B. Human ROMK1A, -B, and -C transcripts were identified in kidney, whereas only human ROMK1A mRNA could be detected in pancreatic islets and other tissues in which human ROMK1 was expressed at low levels. Thus, tissue-specific alternative splicing of human ROMK1 mRNA may result in the expression of a family of ROMK1 proteins.

Adult↗
PubMed1993

Inhibition of histamine secretion by wortmannin through the blockade of phosphatidylinositol 3-kinase in RBL-2H3 cells.

The surface engagement of high affinity immunoglobulin E receptor (Fc epsilon RI) of rat basophilic leukemia 2H3 (RBL-2H3) cells induced histamine secretion and leukotriene release following activation of the tyrosine kinase Lyn together with phosphatidylinositol 3-kinase (PI3-kinase). Wortmannin inhibited the activity of partially purified PI3-kinase from calf thymus, as well as the PI3-kinase activity in anti-PI3-kinase p85 immunoprecipitates from RBL-2H3 cells, at a concentration as low as 1.0 nM and with IC50 values of 3.0 nM, but did not inhibit PI4-kinase activity. The inhibition of PI3-kinase by wortmannin was irreversible. Wortmannin inhibited both Fc epsilon RI-mediated histamine secretion and leukotriene release up to 80% with IC50 values of 2.0 and 3.0 nM, respectively. Wortmannin inhibited PI3-kinase activity in intact cells up to 80% with an IC50 value of 2.0 nM, which is almost equal to those for PI3-kinase in vitro and for histamine secretion and leukotriene release. With anti-wortmannin antibody, we have shown that wortmannin binds to the 110-kDa protein, but not to PI3-kinase 85-kDa regulatory subunit both in vitro and in whole cells. Furthermore, there was a positive correlation between the potencies of wortmannin derivatives as inhibitors of PI3-kinase and as inhibitors of histamine secretion. Wortmannin had no effect on the activation of the tyrosine kinase Lyn. These results suggest that PI3-kinase is involved in the signal transduction pathway responsible for histamine secretion following stimulation of Fc epsilon RI and that wortmannin blocks these responses through direct interaction with the catalytic subunit of this enzyme.

Androstadienes↗
PubMed1993

Common structural and expressional properties of vertebrate caldesmon genes.

We have determined the genomic structure of chicken caldesmon (CaD) gene. The gene, 100-150 kilobases long, is composed of 17 exons. Exons 1a-1, 1a-2, and 1a-3 encode the 5'-terminal sequence specific to the mRNAs for CaDs expressed in gizzard. Exon 1b encodes the 5'-terminal sequence of the brain l-CaD and locates downstream of exons 1a-1, 1a-2, and 1a-3. The genomic construction of the chicken CaD resembles with that of the human CaD. Exon 3 of chicken CaD gene possesses the unique structure similar to that of human CaD gene; the common domain in both h- and l-CaDs (amino acid residues 74-199 for h-CaD and residues 66-191 for l-CaD) and the central repeating domain specific to h-CaD (amino acid residues 200-419) are encoded in exons 3a and 3b, respectively. Of particular interest is that the two consensus 5'-splice sites are found in the borders between exons 3a and 3b, and exon 3b and intron. Therefore, the expressional regulation between h- and l-CaDs can be explained by selection of these 5'-splice sites. Alternative 3'-splice sites also exist at intron/exon junction of exon 14 and the difference in selection of the sites would induce the specific Ala-508 insertion in the brain l-CaD.

Alternative Splicing↗
PubMed1993

Association of HLA-DR and HLA-DQ antigens with congenital dislocation and dysplastic osteoarthritis of the hip joints in Japanese people.

OBJECTIVE: To investigate the frequency of HLA-DR and DQ antigens among patients with congenital dislocation of the hip joint or dysplastic osteoarthritis (OA) and to determine whether tissue typing might contribute to better understanding of these disorders. METHODS: HLA-DR and DQ typing was undertaken in 18 patients with congenital dislocation of the hip joints, 65 patients with dysplastic OA of the hip, 42 patients with primary OA of the knee, and 40 normal controls. Typing for HLA-D antigens was performed using the standard microlymphocytotoxicity method. RESULTS: The frequency of HLA-DR4 in patients with congenital dislocation of the hip joint (61.1%) and patients with dysplastic OA of the hip (58.5%) was significantly increased compared with normal controls (27.5%) (Pcorr < 0.05 and P < 0.01, respectively). The relative risk for HLA-DR4 was 4.1428 and 3.7104, respectively, in these 2 disease groups. The frequency of HLA-DR4 in the patients with primary OA of the knee (35.7%) did not differ significantly from that in normal controls. CONCLUSION: The results strongly indicate that development of congenital dislocation of the hip joint and progression of dysplastic OA of the hip are associated with genes of the HLA-D region.

Aged↗
PubMed1993

Morphologic characteristics, proliferation, and tumor marker expression of two human ovarian carcinoma cell lines in three-dimensional culture.

Two cell lines derived from human serous ovarian adenocarcinoma (KOC-1S, KOC-2S) were cultured three-dimensionally in type I collagen gel, and their morphology, growth kinetics, and tumor marker expression were compared with those of cells grown on plastic dishes. KOC-1S cells were established from a well-differentiated adenocarcinoma and they formed three-dimensional round colonies and tubular structures in collagen gel culture. KOC-2S cells were established from a poorly differentiated serous adenocarcinoma and they proliferated diffusely in a solid pattern to form irregularly shaped colonies in collagen gel culture. The doubling times of both cell lines were longer in collagen gel culture, but the ratio of their doubling times was virtually the same in both culture systems. KOC-1S cells produced CA125 and TPA, while KOC-2S cells only produced TPA. For both cell lines, tumor marker secretion per 10(5) cells was greater in collagen gel that on plastic dishes. These results suggest that human ovarian carcinoma cell lines retain characteristics similar to those in vivo with regard to histologic type, degree of differentiation, and growth kinetics when they are cultured in collagen gel.

Antigens, Neoplasm↗
PubMed1993

Quantitative analysis of revascularisation and new bone formation in experimental bone grafts. The use of an image input and processing system.

Revascularisation and new bone formation in bone grafts has been extensively studied by histological techniques, but the images obtained are very complex and consequently difficult to evaluate quantitatively. We report similar analyses in experimental bone grafts using newer computerised digital techniques. Fresh autografts and fresh and frozen allografts were used. The histological analogue images from them were input digitally into an image processor. The amount of revascularisation and new bone formation could then be quantified in the different grafts. This system has proved to be a useful method of evaluation which could be applied to the quantitative analysis of other histological images.

Angiography↗
PubMed1993

Differences in activation patterns in elbow flexor muscles during isometric, concentric and eccentric contractions.

To investigate the relative activation of the synergistic muscles during three different types of muscle contraction, the electromyograms (EMG) of two elbow flexor muscles, the biceps brachii (BB) and the brachioradialis (BR), have been compared. To accomplish this eight healthy human subjects performed the following elbow flexions against the same load--concentric, eccentric and isometric contractions. The isometric contractions were performed at three elbow angles: 10, 45 and 90 degrees (0 degree equal to full extension). The EMG were recorded by bipolar surface electrodes, and the relative activation between the two muscles was evaluated as the quotient of mean EMG activities (BR/BB). For the isotonic elbow flexions, BR/BB were calculated at three angle divisions: 0-30 degrees, 30-60 degrees and 60-90 degrees. Results indicated that the relative activation of the BR during the concentric contractions was higher than that of the eccentric contraction, particularly at the extended elbow angles, i.e. the BR/BB of the concentric contractions for the elbow joint angles ranging from 0-30 degrees and 30-60 degrees were significantly greater (P < 0.05) than those of the eccentric contractions. During the isometric and eccentric contractions, the BR/BB at the flexed joint angles tended to be greater than those at the extended angles. In contrast, there were no angle-dependent BR/BB variations during the concentric elbow flexions. Further, changing patterns in the EMG power spectra due to the type of contraction were different between BB and BR. These results indicated that the activation pattern in the two elbow flexor muscles varied with the muscle contraction pattern.

Adult↗
PubMed1993

Functional analysis of the gamma-glutamylcysteine synthetase of Escherichia coli B: effect of substitution of His-150 to Ala.

A high expression system of the gamma-glutamylcysteine synthetase gene (gshl) of Escherichia coli B was constructed, and rapid purification of GSH-I was performed. The active site of GSH-I was analysed by chemical modification, and Lys, Arg and His residues seemed to be involved in the active site of the enzyme. Among them, His residues were substituted to Ala by site-directed mutagenesis, and His-150 was found to be essential for the activity of GSH-I.

Alanine↗
PubMed1993

Comparison of postoperative results following terminal esophagoproximal gastrectomy and esophageal transection for esophageal varices.

The results of 44 terminal esophagoproximal gastrectomies (TEPG) and 53 esophageal transections (ET) for esophageal varices, performed during the period between January, 1975 and March, 1989, were retrospectively compared. The results examined prognosis, recurrence of esophageal varices and late postoperative complications. The 5-year survival rates for patients who underwent selective or prophylactic surgery were 85.9% following TEPG and 81.6% following ET. However, the 10-year survival rate for the former group was significantly lower than that for the latter group at 59.3% versus 70.0% (P < 0.05) because of the number of deaths due to hemorrhage and liver failure caused by anastomotic ulcers. The respective 5-year recurrence rates of varices for the TEPG and ET groups were 18.4% and 26.4%, respectively, while the 10-year recurrence rate for the former group was again significantly lower than that for the latter group at 27.1% versus 53.7% (P < 0.01). As for postoperative late complications, reflux esophagitis and/or anastomotic ulcers were found twice as frequently after TEPG as after ET. Thus, although TEPG was more effective for preventing variceal recurrence it left the potential for an anastomotic ulcer to develop, which was the dominant cause of death more than 5 years after surgery.

Adult↗
PubMed1993

Annular pancreas associated with pancreaticobiliary maljunction in an infant.

We report the first known case of an annular pancreas associated with pancreaticobiliary maljunction without cholangiectasis in an infant, aged 2 years and 5 months in Japan. Only two other cases have been reported in Japan both of which were in adults. In our case, the main clinical features were abdominal pain, vomiting and an increasing level of plasma amylase. Endoscopic retrograde cholangiopancreatography (ERCP) was not successful in demonstrating the pancreaticobiliary maljunction due to duodenal stenosis. At operation, a complete type of annular pancreas was found with no enlargement of the common bile duct. We could visualize the pancreaticobiliary maljunction using cholangiopancreatography from the gallbladder during the operation. We then performed duodeno-duodenostomy (side-to-side anastomosis, diamond anastomosis) and portal jejunostomy (Roux en Y anastomosis). The infant was discharged in a good condition at 13 days after the operation. The pattern of the pancreatic ducts was Millbourn's 2a and the type of the duct in the annular portion was Yumura's type I. These results correspond to Lecco's hypothesis that the ring formation originates from the ventral pancreas. It has been further suggested that the cacogenesis and/or dysplasia of the ventral pancreas plays a role in the development at the stage of the pancreaticobiliary maljunction.

Abnormalities, Multiple↗