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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 379 records · Page 21Linked to original sources
PubMed1993

Identification of the plasminogen activator inhibitor-1 binding heptapeptide in vitronectin.

We have shown that a heptapeptide which resides in the middle part of vitronectin (VN) is responsible for binding to plasminogen activator inhibitor-1 (PAI-1). A single PAI-1 binding peptide was isolated from human VN after limited proteolysis with protease V8. The amino acid sequence of the fragment corresponded to residues Gly-115-Glu-121 of VN. A murine monoclonal antibody (JYV-1) raised against human VN bond to the same fragment and inhibited binding of PAI-1 to VN. A synthetic peptide (V-115), comprising residues Gly-115-Glu-121 of human VN, competed with VN for both PAI-1 and JYV-1 in a dose-dependent manner. Synthetic peptide V-111 (Ser-111-Glu-121) had a stronger inhibitory effect than V-115 on binding of PAI-1 or JYV-1 to VN. V-111 also inhibited the binding of human PAI-1 to mouse and rabbit VN. The functional half-life of PAI-1 activity was prolonged approximately 2-fold in the presence of V-111 (1 mM). This stabilizing effect of V-111 was equivalent to intact VN, although a 1000-fold higher molar concentration of V-111 over VN was required. These data indicated that VN residues Gly-115-Glu-121 contain a PAI-1 binding site.

Amino Acid Sequence↗
PubMed1993

Congenital, multiple, bilateral, trigger digits in a child.

Congenital triggering of a digit other than the thumb is a rare. A nine year old boy has been treated for congenital, multiple trigger digits in addition to the thumb. The operative findings were only slight thickening of the flexor pulley and noticeable fusiform swelling of the flexor tendons.

Child↗
PubMed1993

Symptoms and signs in workers exposed predominantly to xylenes.

Surveys were conducted in factories in China where workers were engaged in the production of rubber boots or plastic-coated wire or in printing work, and were exposed to xylene vapors. Based on the data on exposure as monitored by personal diffusive sampling, 175 xylene-exposed workers (107 men and 68 women) were selected as those (1) who underwent all examinations and (2) for whom the sum of the three xylene isomers accounted for 70% or more of the total exposure (on a ppm basis). The intensity of exposure was such that the sum of the three isomer concentrations was 14 ppm as a geometric mean and 21 ppm as an arithmetic mean. As controls, 241 nonexposed workers (116 men and 125 women) were recruited either from the same factories or from factories in the same regions. There was an increased prevalence of subjective symptoms in the exposed workers which were apparently related to the effects on the central nervous system and to the local effects on the eyes, the nose, and the throat, although dose-dependency of the symptoms was evident in only a limited number of cases, possibly because the intensity of exposure was rather low. It was further observed that the findings of hematology and serum biochemistry in respect of liver and kidney functions were generally negative, showing that xylenes are not toxic to the hematopoietic organs, the liver, or the kidney.

Adult↗
PubMed1993

Plasma endothelin-1 concentrations are elevated in acute hepatitis and liver cirrhosis but not in chronic hepatitis.

We measured plasma endothelin-1 (ET-1) concentrations in 20 healthy controls and 63 patients with liver diseases including 9 cases of acute hepatitis (AH), 14 cases of chronic hepatitis (CH), 24 cases of liver cirrhosis (LC), 11 cases of hepatocellular carcinoma with LC (HCC), 3 of primary biliary cirrhosis and 2 of idiopathic portal hypertension. ET-1 levels in AH (5.07 +/- 2.54 pg/ml, mean +/- SD), LC (3.71 +/- 1.17) and HCC (3.08 +/- 0.93) were significantly higher than those in healthy controls (2.18 +/- 0.37). ET-1 levels in AH, LC and HCC were also significantly higher than those in CH (2.05 +/- 0.61). ET-1 levels showed negative correlations with serum albumin levels and Ch-Ease activities, and positive correlations with serum bilirubin levels, AST and ALT activities. However, there was no correlation between plasma ET-1 concentrations and concentrations of serum thrombomodulin which is known to be a marker of injured vascular endothelial cells. In cirrhotic patients, ET-1 levels were significantly influenced by the presence of ascites. The results of the present study suggest that plasma ET-1 concentrations may be a useful clinical indicator for use in the follow-up of patients with chronic liver diseases, e.g., progression from CH to LC, and change in grade of portal hypertension and decompensation in LC.

Acute Disease↗
PubMed1993

Optimization of Butterworth filter for brain SPECT imaging.

A method has been described to optimize the cutoff frequency of the Butterworth filter for brain SPECT imaging. Since a computer simulation study has demonstrated that separation between an object signal and the random noise in projection images in a spatial-frequency domain is influenced by the total number of counts, the cutoff frequency of the Butterworth filter should be optimized for individual subjects according to total counts in a study. To reveal the relationship between the optimal cutoff frequencies and total counts in brain SPECT study, we used a normal volunteer and 99mTc hexamethyl-propyleneamine oxime (HMPAO) to obtain projection sets with different total counts. High quality images were created from a projection set with an acquisition time of 300-seconds per projection. The filter was optimized by calculating mean square errors from high quality images visually inspecting filtered reconstructed images. Dependence between total counts and optimal cutoff frequencies was clearly demonstrated in a nonogram. Using this nomogram, the optimal cutoff frequency for each study can be estimated from total counts, maximizing visual image quality. The results suggest that the cutoff frequency of Butterworth filter should be determined by referring to total counts in each study.

Brain↗
PubMed1993

Molecular cloning of rat growth inhibitory factor cDNA and the expression in the central nervous system.

Human growth inhibitory factor (GIF) is a new metallothionein-related molecule whose expression is markedly reduced in Alzheimer's disease (AD) brain. We have recently isolated a full-length cDNA for human GIF that has a striking homology to metallothioneins (MTs). As an initial step to better understanding of the biological functions of GIF, we have isolated a full-length cDNA for rat GIF. Comparison of the predicted amino acid sequence with that of human GIF revealed a strikingly high homology (84% identity). Rat GIF cDNA also showed a striking homology to rat MT-1 and MT-II (66% and 62% identities on amino acid sequences, respectively). All cysteine residues were conserved among rat GIF, human GIF and MTs, indicating that cysteine residues play an important function in these molecules. Compared to mammalian MTs, there were 3 bp and 12 bp insertions near the amino-terminal and carboxy-terminal regions in the rat GIF. The rat GIF mRNA was found to be expressed exclusively in the central nervous system, being expressed predominantly in rat cortical astrocytes in primary culture. Although the rat GIF mRNA expression was low during the fetal stage, a dramatic increase of the rat GIF mRNA expression was demonstrated during the postnatal period of 10-17 days. These results indicate that transcriptional regulation of the rat GIF gene is quite different from that of MTs despite its strikingly high homology with MTs.

Amino Acid Sequence↗
PubMed1993

Macrodactyly in Proteus syndrome.

A case of Proteus syndrome in a 13-year-old boy with macrodactyly, hemihypertrophy, exostosis of the skull, epidermal naevi, palmar and plantar masses, and scoliosis is reported. Macrodactyly involving the left thumb was treated surgically. The usual findings in macrodactyly, hypertrophy of the digital nerves and proliferation of subcutaneous fat, were not observed in this case. Macrodactyly associated with Proteus syndrome should be distinguished from other forms of macrodactyly because of its poor prognosis and high rate of recurrence.

Adolescent↗
PubMed1993

Reduction of vasoreactivity and thrombogenicity with laser-thermal angioplasty: comparison with balloon angioplasty.

UNLABELLED: The vasoreactivity and thrombogenicity of laser-thermal angioplasty were examined and compared with those of balloon angioplasty in an atherosclerotic rabbit iliac artery. Eight rabbits underwent laser-thermal angioplasty with a 1.7-mm hot-tip probe activated at 7 W with a probe temperature of 126 +/- 19 degrees C in one iliac artery. The other iliac artery was treated with balloon angioplasty using a 2.0-mm balloon. Angiographic luminal diameter increased from 0.19 +/- 0.15 to 1.54 +/- 0.35 mm by laser and from 0.29 +/- 0.22 to 1.84 +/- 0.20 mm by balloon (P less than 0.0001, respectively). However, it decreased to 1.34 +/- 0.42 for laser and 0.45 +/- 0.39 for balloon 60 minutes later (P less than 0.0001 vs immediately post). Both iliac arteries were visualized using angioscopy, which revealed thrombotic obstruction of 91% stenosis in the ballooned artery and 8% stenosis in the lased artery. Vasoreactivity of treated vessels was also investigated. Segments 3-mm long were obtained from either treated artery or control artery and examined for noradrenaline (10 -7 M) contraction. The segments were then mounted isometrically with 1 g tension in Krebs-bicarbonate buffer. Developed tension was 0.13 +/- 0.21 g for laser thermal and 2.33 +/- 0.4 g for its control (P less than 0.0001), and 0.15 +/- 0.16 g for balloon dilatation and 2.12 +/- 0.43 g for its control (P less than 0.0001). Neither acetylcholine at 10 -6 M or papaverine at 10 -4 M induced relaxation of treated segments. Histology showed slight thermal injury at thermally-treated sites without thrombus, and intimal and medial dissection with thrombus formation at balloon dilated site. IN CONCLUSION: (1) neither a laser-thermal recanalized or a balloon dilated obstructed artery is vasoreactive to constrictive or relaxant agents; and (2) laser-thermal angioplasty results in less thrombogenicity than balloon angioplasty under moderate probe temperature.

Angioplasty, Balloon, Coronary↗
PubMed1993

Organ culture with proinflammatory cytokines reproduces impairment of the beta-adrenoceptor-mediated relaxation in tracheas of a guinea pig antigen model.

The challenge of previously sensitized guinea pigs with aerosolized ovalbumin resulted in impairment of the beta-adrenoceptor-mediated relaxation as measured by the in vitro isometric assay of tracheas preconstricted with endothelin-1 or carbamylcholine. Numbers and affinities of beta-adrenoceptors in lung membranes of these animals were not altered under these conditions, although the antigen challenge caused an inflammatory response, as evident from the accumulation of inflammatory cells in the bronchoalveolar lavage fluids. In order to investigate the pathophysiologic role of inflammation in hyperreactive airways, isolated guinea pig tracheas were cultured with proinflammatory cytokines such as human recombinant tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), or interleukin-2 (IL-2). None of these cytokines affected the contractile response of tracheas to carbamylcholine. After preconstriction with carbamylcholine, the TNF-alpha- and IL-1 beta-pretreated tissues produced a significant reduction in the maximal relaxation induced by isoproterenol, whereas the IL-2 pretreatment had no effect. The reduction of the isoproterenol-mediated relaxation by the IL-1 beta treatment was time and dose dependent. Our present observations suggest that in vitro incubation of naive tracheas with proinflammatory cytokines is able to reproduce apparent beta-adrenoceptor impairment as seen in the airways of antigen-challenged guinea pigs of asthma model.

Animals↗
PubMed1993

Three cases of bovine extreme tetralogy of Fallot.

Three female Holstein calves having cyanosis of the visible mucous membrane, exercise intolerance and systolic murmur were examined. Extreme Tetralogy of Fallot with ventricular septal defect was confirmed at autopsy. All of the intrapericardial pulmonary arteries were completely absent in two cases. In the other case, the atretic pulmonary trunk, with a bicuspid valve, rose from a very small chamber which was located on the blind-ending muscular infundibulum. There was no connection between the atretic pulmonary trunk and the right ventricle.

Animals↗
PubMed1993

Loss of vasoreactivity by laser thermal energy or argon laser irradiation.

Vasoreactivity of laser-treated vessels was investigated in two different experimental conditions. The canine left circumflex coronary artery (LCx) was lased under perfusion with Krebs-bicarbonate buffer by means of a thermal laser (hot-tip probe, HT) at 7 W for 6 seconds and an argon laser beam through a 300 microns optical fiber at 3 W (tip power) for 1 second at 12 spots. A nontreated segment of the LCx served as a control. Two 3-mm long segments were obtained from the treated segment: one to measure the results of potassium (K) induced contraction, and another 3, 4 diaminopyridine (DAP; K channel inhibitor) induced contraction. In 11 instances, coronary angiography of the perfused artery showed less than 50% stenosis after laser treatment. The segments were then mounted isometrically with 1 g tension in Krebs-bicarbonate buffer. Contraction was induced either with 30 mM KCI or 10(-2) M DAP and expressed as developed tension (gram; g). KCI induced vasocontraction of 4.15 +/- 0.93 g in the control, 0.33 +/- 0.71 g in laser irradiated segments (P < 0.0001 vs control), and 0.02 +/- 0.06 g in thermally-treated segments (P < 0.0001 vs control). DAP induced vasocontraction of 5.21 +/- 1.32 g in the control, 0.39 +/- 0.83 g in laser irradiated segments (P < 0.0001 vs control), and 0.07 +/- 0.13 g in thermally treated segments (P < 0.001 vs control). In 4 instances, more than 50% stenosis remained and additional balloon dilatation reduced the stenosis to less than 50%. The lesions also showed reduced vasoreactivity. In vivo thermal angioplasty resulted in reduced vasoreactivity compared to control in 4 anesthetized dogs. Thus, laser and thermal angioplasty reduced vasoreactivity induced by either KCI or 3, 4 DAP. Neither acetylcholine at 10(-6) M nor papaverine at 10(-4) M was able to induce relaxation of treated segments. In conclusion, 1) the lased coronary artery loses its vasoreactivity to either a constrictive or relaxing agent, 2) although stenosis may be produced by laser energy, additional balloon dilatation can reduce residual stenosis, and 3) laser thermal or argon laser angioplasty may prevent severe coronary spasm.

4-Aminopyridine↗
PubMed1993

Reduction of thrombogenicity with argon laser angioplasty. Comparison with balloon angioplasty.

Direct argon or thermal laser angioplasty (LA) was evaluated for thrombogenicity using angioscopy, and compared with balloon angioplasty (BA). In each of 8 dogs, 4 segments (both proximal and distal iliac arteries) were treated by laser-thermal and/or balloon angioplasty. One segment was treated by balloon angioplasty and 3 other segments were treated with either thermal LA with 7 W using a "Hot-Tip" laser probe (2.0 mm), or BA and thermal LA, or a special optical probe which emits a 3 W argon laser beam. Mean percent area stenosis by thrombus was 44 +/- 23 in balloon-dilated, 23 +/- 21 in thermally-treated and balloon-dilated, 3 +/- 3 in thermally-treated, and 1 +/- 4 in directly-lased segments at 30 min. It was 62 +/- 28 in balloon dilated, 31 +/- 29 in thermally-treated and balloon-dilated, 5 +/- 6 in thermally-treated, and 1 +/- 2 in directly-lased segments at 60 min. Balloon-inflated segments had the highest percent area stenosis which was significantly higher than that of either the direct laser or thermally-treated segments (p < 0.0005). Histology showed thermal necrosis in laser-treated sites, and wall tears in BA sites. Thus, LA can provide a less thrombogenic arterial surface than BA.

Angioplasty, Balloon↗
PubMed1993

Functional morphology of the lymphatic system in the monkey diaphragm.

A morphological study of the lymphatic system in the diaphragm of adult Japanese monkeys was carried out using intraperitoneal injection with India ink, light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. For SEM examination of the subperitoneal connective tissue, the peritoneal mesothelium was stripped by either the NaOH/sonication microdissection techniques or the NaOH digestion method. Light microscopy of 1 micron Epon sections and TEM of thin sections demonstrated that lymphatic capillaries were distributed in the subperitoneal connective tissue of the muscular and tendinous portions. Gaps (stomata) between neighboring cells of the peritoneal mesothelium were occasionally encountered. In SEM observations, stomata with oval shapes and various sizes were abundantly seen in the peritoneal mesothelium, but were absent from the pleural mesothelium. It deserves particular note that a large number of foramina were detected in the subperitoneal connective tissue. The cluster of the foramina was similar in appearance to the "macula cribriformis" depicted by KIHARA (1956). Carbon particles injected into the monkey peritoneal cavity passed through the peritoneal stomata and then the macula cribriformis, ultimately to enter the lymphatic capillaries. This paper also discusses the functional implication of the lymphatic system in the diaphragm.

Animals↗
PubMed1993

[Antigen-induced dynamic alterations of endothelin receptors--guinea pig lung tissues].

Endothelins (ETs) are a family of peptides with potent constrictive activity in vascular and treacheal smooth muscle. The lung tissues are abundant in these peptides and their receptors; the peptides are produced by endothelial cells and airway epithelial cells, while its receptor is mainly located on smooth muscle. Therefore, it has been proposed that endothelins act in a paracrine fashion on nearby smooth muscle, thus regulating its tone. However, little is known about its physiological and pathological roles in pulmonary functions. We hypothesized that ET plays an important role in bronchoconstriction elicited by antigen challenge. In order to test this hypothesis, we investigated tracheal contractile activities and ET-receptors by employing an animal model in guinea pigs. Here, we report that guinea pigs who were sensitized followed by multiple challenges with the antigens had alterations of ET receptor(s) with respect to number and affinity.

Animals↗
PubMed1993

[A case of round atelectasis related to spontaneous pneumothorax in a patient with neurilemmomatosis].

A 60-year-old man was admitted to our department for investigation of abnormal shadows on his chest X-ray. He had been diagnosed as having neurilemmomatosis in 1987. His chest X-ray showed nodular shadows in left S5 and S8 and localized spontaneous pneumothorax in left lung field. The nodular shadows, which were in contact with thickening of the pleura, showed curved shadows of bronchi and vessels (so-called comet tail sign). We suspected that they were round atelectasis, but to confirm the diagnosis and to treat the pneumothorax, limited resection of the lung and resection of the bulla were performed. The diagnosis of round atelectasis was confirmed by histological findings. Round atelectasis related to spontaneous pneumothorax is a very rare condition; however, we consider this to be an important case for understanding the pathogenesis of round atelectasis.

Humans↗
PubMed1993

Diagnostic impression cytology for herpes simplex keratitis.

Herpes simplex virus (HSV) antigens in corneal or conjunctival epithelial lesions were detected by impression cytology. Specimens were obtained using a nitrocellulose membrane and were stained by the peroxidase-antiperoxidase method. HSV antigens were demonstrated in 30 of 32 patients with herpes simplex keratitis or conjunctivitis. Impression specimens of dendritic or stellate keratitis lesions exhibited precise replicas of corneal lesions with numerous antigen-positive cells. HSV antigens were also detectable in some of the minute stellate and/or punctate epithelial keratitis lesions even during the course of antiviral treatment. Impression cytology is noninvasive and useful for a rapid etiological diagnosis of herpetic epithelial lesions.

Antigens, Viral↗