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Biomedical subjects

Y Takada

Publications and source records attributed to Y Takada.

At least 523 records · Page 29Linked to original sources
PubMed1989

The primary structure of the alpha 4 subunit of VLA-4: homology to other integrins and a possible cell-cell adhesion function.

VLA-4 is a cell surface heterodimer in the integrin superfamily of adhesion receptors. Anti-VLA-4 antibodies inhibited cytolytic T cell activity, with inhibitory activity directed against the effector T cells rather than their targets. Thus, whereas other VLA receptors appear to mediate cell--matrix interactions, VLA-4 may have a cell--cell adhesion function. To facilitate comparative studies of VLA-4 and other integrins, cDNA clones for the human alpha 4 subunit of VLA-4 were selected and then sequenced. The 3805 bp sequence encoded for 999 amino acids, with an N-terminus identical to that previously obtained from direct sequencing of purified alpha 4 protein. The alpha 4 amino acid sequence was 17-24% similar to other integrin alpha chains with known sequences. Parts of the alpha 4 sequence most conserved in other alpha chains include (i) the positions of 19/24 cysteine residues, (ii) three potential divalent cation binding sites of the general structure DXDXDGXXD and (iii) the transmembrane region. However, alpha 4 stands apart from all other known integrin alpha subunit sequences because (i) alpha 4 has neither an inserted I-domain, nor a disulfide-linked C-terminal fragment, (ii) its sequence is the most unique and (iii) only alpha 4 has a potential protease cleavage site, near the middle of the coding region, which appears responsible for the characteristic 80,000 and 70,000 Mr fragments of alpha 4.

Amino Acid Sequence↗
PubMed1989

Changes in cerebral hemodynamics following encephalo-duro-arterio-synangiosis (EDAS) in young patients with moyamoya disease.

To evaluate the effect of encephalo-duro-arterio-synangiosis, (EDAS), we obtained follow-up angiograms and measured regional cerebral blood flow in 21 young patients with Moyamoya disease. Carotid fork stenosis continued to progress after EDAS, although angiography demonstrated a marked increase in the number of middle cerebral artery branches via implanted arteries. Preoperative cortical blood flow was lower than normal. The post-EDAS increases in hemispheric and cortical flow were significant in patients with transient ischemic attacks, but not in patients with infarction. The increase in cortical flow at the site of EDAS was first noted 2 weeks after EDAS.

Adolescent↗
PubMed1989

The primary structure of the VLA-2/collagen receptor alpha 2 subunit (platelet GPIa): homology to other integrins and the presence of a possible collagen-binding domain.

VLA-2 (also called gpIa/IIa on platelets) is a collagen receptor with a unique alpha subunit and a beta subunit common to other adhesion receptors in the VLA/integrin family. Multiple cDNA clones for the human VLA-2 alpha 2 subunit have been selected from a lambda gtll library by specific antibody screening. The 5,374-bp nucleotide sequence encoded for 1,181 amino acids, including a signal peptide of 29 amino acids followed by a long extracellular domain (1,103 amino acids), a transmembrane domain, and a short cytoplasmic segment (22 amino acids). Direct sequencing of purified alpha 2 protein confirmed the identity of the 15 NH2-terminal amino acids. Overall, the alpha 2 amino acid sequence was 18-25% similar to the sequences known for other integrin alpha subunits. In particular, the alpha 2 sequence matched other integrin alpha chains in (a) the positions of 17 of its 20 cysteine residues; (b) the presence of three metal-binding domains of the general structure DXDXDGXXD; and (c) the transmembrane domain sequence. In addition, the alpha 2 sequence has a 191-amino acid insert (called the I-domain), previously found only in leukocyte integrins of the beta 2 integrin family. The alpha 2 I-domain was 23-41% similar to domains in cartilage matrix protein and von Willebrand factor, which are perhaps associated with collagen binding. The NH2-terminal sequence reported here for alpha 2 does not match the previously reported alpha 2 NH2-terminal sequence (Takada, Y., J. L. Strominger, and M. E. Hemler. 1987. Proc. Natl. Acad. Sci. USA. 84:3239-3243). Resolution of this discrepancy suggests that there may be another VLA heterodimer that resembles VLA-2 in size but has a different amino acid sequence.

Amino Acid Sequence↗
PubMed1989

A deacylation enzyme for aculeacin A, a neutral lipopeptide antibiotic, from Actinoplanes utahensis: purification and characterization.

An enzyme, tentatively termed aculeacin A acylase, useful in preparing deacylated peptides which are used as starting material for semisynthetic antifungal antibiotics, was purified from the culture filtrate of Actinoplanes utahensis NRRL12052. The purification involved ultrafiltration and column chromatographies on DEAE-cellulose, hydroxyapatite, and Butyl-Toyopearl 650M. The purified enzyme was composed of two dissimilar subunits with molecular weights of 55,000 and 19,000. The subunits were dissociated in the presence of 0.1% SDS or 6 M guanidine hydrochloride; the dissociation accompanied loss of acylase activity. The enzyme was fully active at pH 7.0 and at 60 degrees C. Its pI was estimated to be above 10.25. The Km and Vmax for aculeacin A were 1.53 mM and 39.7 mumol/min/mg-protein, respectively.

Actinomycetales↗
PubMed1989

Golden proportion for maxillofacial surgery in Orientals.

The facial position and balance of eyes, nose, and mouth in typical Japanese individuals were investigated, based on the golden proportion for each of these relationships. We found that Japanese tend to have a longer upper lip and shorter chin length compared with Caucasians. We believe that this tendency represents a general facial characteristic of the Oriental population. Each ratio obtained from determinations by our method was used for preoperative and postoperative aesthetic analysis in maxillofacial surgery. This method is considered useful because it permitted us to understand quantitatively the positional relationship and the balance of eyes, nose, and mouth in the face and to make comparisons with typical subjects.

Adult↗
PubMed1989

Systemic candidiasis with DIC and candida endophthalmitis in a postoperative neonate.

A full-term male neonate, weighing 2540 g at birth, was admitted to hospital on day 2 because of vomiting and severe dehydration. Duodeno-duodenostomy was performed on day 5 for congenital duodenal atresia. The child was well postoperatively until day 9, when he developed fever. Intermittent fever continued despite treatment with several antibiotics. He became seriously ill on day 15 and developed disseminated intravascular coagulation. Treatment with antifungal drugs (amphotericin B and 5-flucytosine) was effective for systemic candidiasis, but candida endophthalmitis developed. There was a persistent vitreous lesion in the left eye, which after cessation of therapy has been improving gradually. Systemic candidiasis and candida endophthalmitis should be considered in neonates who develop signs of sepsis postoperatively.

Candidiasis↗
PubMed1989

Formation of crystals of the insecticidal proteins of Bacillus thuringiensis subsp. aizawai IPL7 in Escherichia coli.

Escherichia coli JM103 cells harboring expression plasmid pTB1 or pKC6 synthesized the 130- and 135-kilodalton insecticidal proteins, respectively, of Bacillus thuringiensis subsp. aizawai IPL7, and both products accumulated as cytoplasmic inclusion bodies. Amorphous inclusions which contained contaminating proteins, together with the corresponding insecticidal proteins, were formed in cultures at 37 degrees C, but bipyramidal crystals practically free of contaminants were observed at 30 degrees C. Although 9.8% of the amino acids were substituted between these two proteins, both protein crystals had the same shape as those of the parental B. thuringiensis strain, which produced both proteins.

Bacillus thuringiensis↗
PubMed1989

Enhancement of the activation of Glu-plasminogen by urokinase in the simultaneous presence of tranexamic acid or fibrin.

The activation rate of Glu-plasminogen (Glu-plg) by urokinase (UK) was enhanced in the presence of either tranexamic acid or fibrin with an increase in the catalytic rate constant (kcat). The maximum increase in kcat was obtained at 0.5 mM of tranexamic acid and 0.1 microM of fibrin. Km did not change. The addition of fibrin to 1 mM tranexamic acid resulted in a further increase in kcat of the UK activation of Glu-plg. On the other hand, the addition of tranexamic acid to 0.1 microM fibrin further increased kcat of the UK activation of Glu-plg. Thus, stimulatory effects were observed on the activation of Glu-plg by UK in the simultaneous presence of tranexamic acid and fibrin. Fibrin-binding sites on the kringle 5 of Glu-plg may be involved in the further increase in the activation rate of Glu-plg by UK in the presence of both fibrin and tranexamic acid in comparison to that in the presence of tranexamic acid alone. Possibly, the Glu-plg binding with both tranexamic acid and fibrin (at kringle 5) may be most effectively activated by UK. It is also suggested that two molecules of Glu-plg bind to one molecule of fibrin monomer.

Cyclohexanecarboxylic Acids↗
PubMed1989

Measurement of urinary trypsin inhibitor in urine, plasma and cancer tissues of patients with stomach cancer.

Antiserum was obtained from rabbits immunized with a highly purified preparation of urinary trypsin inhibitor (UTI) conjugated with rabbit serum albumin. Anti-UTI antibody did not cross-react with antibody against inter-alpha-trypsin inhibitor (I alpha I) as determined by immunodiffusion against human plasma. A highly sensitive enzyme immunoassay was developed for the determination of UTI-related antigens (UTIR) in plasma, urine and cancer tissues. The level of UTIR correlated with UTI activity in urine. UTIR levels in urine and plasma did not change with age, but UTIR levels were higher in the stomach cancer tissue than in the surrounding stomach mucosa. UTIR levels did not correlate with I alpha I levels in the plasma of patients with stomach cancer, thus the increase was not considered due to the contamination of circulating I alpha I in the cancer tissues.

Adolescent↗
PubMed1989

Plasminogen activators: possible roles in cell proliferation.

Plasminogen activators (PAs) convert plasminogen to plasmin by the cleavage of the Arg-Val bond. There are two distinct types of PA, tissue type (t-PA) released from the endothelial cells of the blood vessels and urinary type (u-PA) released from urinary tubules. u-PA was found to be released from activated macrophages and virally transformed cells. t-PA was also found to be released from breast cancer cells induced by carcinogens or melanoma cells. In structure, t-PA has a finger domain homologous to fibrin-binding domain of fibronectin and a growth factor domain homologous to the epidermal growth factor. u-PA has no finger domain but has a growth factor domain. It is proposed that PA may be important in tumor growth due to the stimulation of tumor cells through binding of growth factor domain to its receptor of tumor cells. Another hypothesis is that PA may activate procollagenase to collagenase, which digests collagen to facilitate tumor growth. We have measured the concentrations of t-PA and u-PA in plasma, urine and tumor tissues of patients with cancer of the digestive tract and patients with uterine or ovarian tumors. The results indicate that the concentrations of u-PA increased in urine, plasma and cancer tissues of patients with cancer of the digestive tracts whereas no increase was observed in t-PA levels. On the other hand, the concentration of t-PA increased mostly in plasma of patients with uterine and ovarian cancers, but t-PA levels in tissues did not increase in patients with uterine and ovarian cancer.

Cell Division↗
PubMed1989

[A case of spontaneous pneumomediastinum in a trombonist].

A case of spontaneous mediastinal emphysema in a 21-year-old female trombonist was reported. During light work, she experienced pain in her neck which later radiated into her chest. She had neither causal disease nor episode of straining at the onset of her work. On admission, physical examination revealed subcutaneous emphysema over the upper part of the chest and neck, and mediastinal crunch on auscultation (Hamman's sign). Roentgenograms revealed the presence of a considerable amount of air in the mediastinum and this extended upward through the mediastinum into the soft tissue of the neck bilaterally. The chest and neck CT yielded clearer information concerning the location and degree of mediastinal emphysema. She was treated with bed rest and recovered completely within five days. Spontaneous mediastinal emphysema without causal disease or apparent precipitating episode is infrequently recognized. In our case, though the trombonist had no apparent straining episode, the causative factor can be assumed to be the tenderness of the alveoli originating from frequent over-inflations of the lungs and high intra-alveolar pressures of about 150 cmH2O during trombone performance, which may result in alveolar rupture under normal intralveolar pressures.

Adult↗
PubMed1989

[Delayed lung scintigraphy with N-isopropyl-I-123-p-iodoamphetamine in lung cancer and inflammatory disease].

Lung studies with N-Isopropyl-I-123-p-Iodoamphetamine (IMP) were performed on patients with lung cancer or inflammatory disease. In the present study, we evaluated the usefulness of the delayed scintigraphy. The subjects consisted of 27 patients with lung cancer (34 lesions), 3 with radiation pneumonitis, 2 with interstitial pneumonitis, 2 with old tuberculous lesion (tuberculomas), 1 with diffuse panbronchiolitis, 1 with pneumonia and 1 with lung abscess. The delayed scintigraphy was performed 24 hr after intravenous injection of 3 mCi IMP, in sitting position. In 10 patients, SPECT images were obtained following the delayed scintigraphy. Delayed scintigraphic appearances of lung cancer were classified into 5 types, high IMP uptake in the area congruent with the lesion of atelectasis and/or obstructive pneumonia (Type I), high IMP uptake in the area surrounded the tumor (Type II), a defect in the area consistent with the tumor and no high IMP uptake in the area surrounded the tumor (Type III), high IMP uptake in the area almost congruent with the tumor (Type IV) and no significant change (Type V). Excluding 10 lesions with Type IV or V, no IMP uptake was seen in the areas congruent with the tumors. Type II was the most frequently observed pattern. Normal scintigrams (Type V) were observed in 8 lesions, whose sizes were fairly small. There was no definite trend caused by difference in histological types of cancers. In 8 patients with viable inflammatory disease of the lung, the delayed scintigrams showed high IMP uptake in the areas congruent with the abnormalities on chest roentgenograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Case-control study of moyamoya disease].

The cause of Moyamoya disease is still unknown. We made a research about the factors closely related to Moyamoya disease through a case-control study. The number of cases studied was 66. Controls were selected from among patients' friends, matched as to sex, age and residential area. Questionnaires were sent to the cases and the respective controls by mail. The questions were about past history, developmental history, school records, habitual factors, dietary habits and pets. The first symptoms and age at onset were also surveyed in the cases. The response rate was 84.8% (56 cases) of the cases and 76.5% (101 cases) out of the 132 controls. There was no significant difference in the prevalence of tonsillitis, conjunctivitis, otitis media, and bronchitis. Odds ratio of fever of unknown origin is 2.793 and X2 is 7.213. Diseases whose odds ratio was over 1 were herpes, appendicitis, bronchitis, asthma, anemia, dental caries, head injury and drug allergy. But all of them were not significantly prevalent. Odds ratios of school records were 4-9 and X2 were 4-17 from elementary to junior high school. Odds ratio of western dishes was 2.709 and X2 was 5.189. There was no significant difference as to pets kept. We could not find overt relationships between Moyamoya disease and diseases of head and neck like tonsillitis.

Adolescent↗
PubMed1989

[A case of pseudotumor cerebri associated with colon cancer].

A case of pseudotumor cerebri associated with iron deficiency anemia due to colon cancer is reported in a 37-year-old woman. Her initial symptoms were vomiting and severe headache. On physical examination, no lymph nodes and abdominal mass were palpable but marked anemia was noted in her skin and conjunctiva . Neurological examination revealed papilledema in her both eyes and stiff neck. There was no abnormal findings on CT scan on admission. Spinal puncture revealed CSF pressure as high as 620 mmH2O with normal cells, protein, sugar and chloride levels. Hematological examination revealed iron deficiency anemia and thrombocytosis. Angiography at third day revealed no sinus occlusion, but retention of contrast media was seen on the cortical vein of parietal lobe and right transverse sinus. Brain scintigram at sixth day revealed mild accumulation in left parietal lobe, so small venous infarction was suggested. There were two circumscribed stenotic lesions of right ascending colon in the barium enema, and right hemicolectomy was achieved. The pathological diagnosis was adenocarcinoma. The symptoms of pseudotumor cerebri was completely disappeared soon after the surgery together with resolution of anemia. She lives with no deficits now 1 year 3 months after surgery. In conclusion much attention is necessary to a patient of pseudotumor cerebri with iron deficiency anemia for the presence of cancer, because not only this central nervous system lesion is reversible and curable but also the cancer itself may be curable by surgery.

Adenocarcinoma↗