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Biomedical subjects

E Yoshida

Publications and source records attributed to E Yoshida.

At least 73 records · Page 4Linked to original sources
PubMed1994

C-type galactoside-binding lectin from Bothrops jararaca venom: comparison of its structure and function with those of botrocetin.

A Ca(2+)-dependent type (C-type) galactoside-binding lectin was purified from venom of the snake Bothrops jararaca by thiodigalactoside-Sepharose affinity column chromatography. B. jararaca lectin is a disulfide-linked homodimer composed of 14-kDa subunits. The N-terminal 55-residue amino acid sequence was determined and appeared to belong to the animal C-type lectin family. This 55-residue sequence showed 37% identity with botrocetin, an exogenous von Willebrand factor modulator purified from the same venom, and 85% identity with a lectin from rattlesnake (Crotalus atrox) venom. B. jararaca lectin showed Ca(2+)-dependent hemagglutination activity but did not induce platelet aggregation in the presence or absence of Ca2+ and von Willebrand factor and did not inhibit platelet aggregation induced by botrocetin and von Willebrand factor. On the other hand, botrocetin, which also contains a C-type lectin motif in the N-terminal sequence, did not show hemagglutinating activity toward rabbit and human erythrocytes, nor binding activity toward immobilized glycoproteins. These results indicate that at least two structurally similar but functionally distinct proteins, both belonging to the C-type lectin family, are present in the venom of B. jararaca.

Amino Acid Sequence↗
PubMed1994

Immunohistochemical demonstration of bikunin, a light chain of inter-alpha-trypsin inhibitor, in human brain tumors.

The presence and localization of bikunin (HI-30, or acid-stable protease inhibitor), a light chain of inter-alpha-trypsin inhibitor, was examined in 30 brain tumors employing immunohistochemical methods. The brain tumors involved 13 kinds of histological diagnosis. Bikunin immunoreactivity was detected in all of the brain tumors examined. Fibrillary staining of the glial processes was observed in astrocytoma, oligodendroglioma, and schwannoma. Intracytoplasmic staining in the interstitial cells, reactive astrocytes, and macrophages was noted in medulloblastoma, ependymoma, and meningioma. Metastatic tumors demonstrated intense immunoreactivity in the tissues surrounding the tumor cells. Neuronal cells revealed no bikunin immunoreactivity. There was no correlation between the intensity of staining and histologic type or grading of malignancy. In view of our earlier report that bikunin was present in the connective tissues around the site of cancer invasion, the above findings suggest that bikunin may play an important role in defense or repair at the tissue destruction and degeneration site.

Brain Neoplasms↗
PubMed1994

Cerebrospinal fluid levels of superoxide dismutases in neurological diseases detected by sensitive enzyme immunoassays.

We measured cerebrospinal fluid (CSF) levels of Cu/Zn superoxide dismutase (Cu/Zn SOD) and Mn superoxide dismutase (Mn SOD) using enzyme immunoassays in 196 neurological patients and 44 controls. The mean Cu/Zn SOD level was 55.8 +/- 27.6 (SD) ng/ml and the Mn SOD, 8.0 +/- 2.5 ng/ml in the controls. Cu/Zn SOD or Mn SOD levels showed neither age-nor sex-related differences in the controls. Both SODs were markedly elevated in cerebrovascular diseases, bacterial meningitis and encephalitis. Mn SOD alone was significantly elevated in neurodegenerative diseases. We compared SODs with CSF levels of neuron-specific enolase (NSE) and S-100b protein (S-100b) in cerebral infarction and bacterial meningitis. Both SODs were correlated with NSE and S-100b in patients with cerebral infarction, but not in those with bacterial meningitis. This means that elevations of SODs in CSF may not only be due to leakage from damaged nervous tissues, but also to the induction of SOD in lesions. We conclude that the mean SOD levels were elevated in various neurological diseases, and their varied magnitudes may be associated with the underlying diseases.

Adolescent↗
PubMed1994

BE-23372M, a novel and specific inhibitor for epidermal growth factor receptor kinase.

The fungal metabolite BE-23372M is a structurally novel protein kinase inhibitor. Its IC50 for epidermal growth factor (EGF) receptor kinase was 0.03 microM. IC50 values of BE-23372M for other protein tyrosine kinases, erbB-2, p43v-abl, insulin receptor kinase, and p60c-src were 0.42, 1.0, 3.3, and 4.5 microM, respectively, and the IC50 for protein kinase C, a serine/threonine kinase, was 4.1 microM. Cdc2 kinase, casein kinases I and II and cAMP-dependent protein kinase were not inhibited by 20 microM BE-23372M. A kinetic study showed that BE-23372M was competitive with respect to the substrate peptide and to ATP. Autophosphorylation of solubilized EGF receptor kinase was clearly inhibited by 0.1 microM BE-23372M. Autophosphorylation of EGF receptor in A431 cells was also inhibited. These results show that BE-23372M is a potent and specific EGF receptor kinase inhibitor. It should be a valuable tool for EGF receptor kinase research.

Amino Acid Sequence↗
PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. I. Producing organism, fermentation, isolation and biological activities.

BE-23372M, a novel protein tyrosine kinase inhibitor, was isolated from the culture broth of a fungus. The producing strain, F23372, was identified as Rhizoctonia solani, based on the cultural and morphological characteristics. The active principle was extracted from the mycelium with acetone and purified by solvent extraction, silica gel column chromatography and Sephadex LH-20 column chromatography. BE-23372M showed strong inhibitory activity against EGF receptor kinase with IC50 values of 0.02 and 0.03 microM on two different substrates, whereas IC50 values against protein kinase C and cAMP-dependent protein kinase were 4.5 and > 20 microM, respectively. The compound inhibited the growth of A431 human epidermoid carcinoma and MKN-7 human stomach cancer cell lines with IC50 values of 8 and 24 microM, respectively.

Amino Acid Sequence↗
PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. II. Physico-chemical properties and structure elucidation.

BE-23372M, a new protein tyrosine kinase inhibitor, has been obtained as a reddish orange solid. The compound, C17H12O6, HRFAB-MS: m/z 312.0625 (M)+, is an acidic substance, showing UV (MeOH) lambda max (epsilon) 266 (8,800), 426 nm (20,400), and IR (KBr)vmax 1752(C = O) and 3298(OH) cm-1. The structure of BE-23372M, (E)-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-fur anone, has been elucidated by 1H and 13C NMR studies.

Chromatography, Thin Layer↗
PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. III. Synthesis.

In a preceding paper, the physico-chemical properties and structural elucidation of BE-23372M, a potent novel protein tyrosine kinase inhibitor, were described. In this paper, we report the synthesis of BE-23372M from 3-(3,4-dimethoxybenzoyl)propionic acid and veratraldehyde or 3,4-diacetoxy-benzaldehyde. The structure of BE-23372M was confirmed to be (E)-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-fur anone.

Furans↗
PubMed1994

The pedicle latissimus dorsi transfer for reconstruction of the plexus brachialis and brachium.

To reconstruct the area from the brachial plexus to the upper arm, pedicle latissimus dorsi muscle transfer was performed in 16 patients. Nine patients underwent functional bipolar transfer for reconstruction of elbow flexion. The surgical results were satisfactory in 6 patients, but were unsatisfactory in 3 because of an incorrect preoperative assessment of the strength of the latissimus dorsi muscle and an unsuitable length of transferred muscle in 2 patients, and because of progression of spastic paralysis caused by cervical myelopathy in the third patient. Seven patients with skin loss and an unstable scar underwent aesthetic unipolar transfer in which the exposed nerve, neurovascular bundle, bone, and joint were covered by a musculocutaneous flap with good vascularity. The surgical results were successful in all 7 patients. Infection was present before transfer in 4 of the 16 patients, but it was successfully treated by simultaneous radical debridement of the infected wound and latissimus dorsi transfer.

Adolescent↗
PubMed1993

Alboaggregin-B and botrocetin, two snake venom proteins with highly homologous amino acid sequences but totally distinct functions on von Willebrand factor binding to platelets.

Alboaggregin-B (AL-B) (Peng et al., Biochemistry (1991) 30, 11529-11536) was highly purified from the snake venom of Trimeresurus albolabris and characterized structurally and functionally, comparing with botrocetin, another snake venom protein recently characterized (Usami et al., Proc. Natl. Acad. Sci. USA (1993) 90, 928-932). Both the venom proteins are a heterodimer and show a high degree of sequence homology to each other and also to C-type lectins. Botrocetin specifically binds to von Willebrand factor (vWF), whereas AL-B binds to platelet glycoprotein (GP) Ib without affecting the binding of botrocetin to vWF. The binding of AL-B to GPIb does not potentiate the platelet aggregation even by exogenous fibrinogen, suggesting that AL-B binding to GPIb does not activate GPIIb/IIIa complex.

Amino Acid Sequence↗
PubMed1993

Induction of topoisomerase I-mediated DNA cleavage by a new indolocarbazole, ED-110.

ED-110 is a new semisynthetic antitumor agent derived from a novel indolocarbazole antibiotic, BE-13793C, produced by an actinomycete. ED-110 induced topoisomerase I-mediated DNA cleavage in vitro as strongly as camptothecin, whereas topoisomerase II-mediated DNA cleavage was not induced by this agent. Exposure of P388 cells to ED-110 caused a typical topoisomerase toxicity, i.e.: formation of cleavable complexes; inhibition of nucleotide synthesis rather than protein synthesis; and cell cycle arrest in G2. ED-110 inhibited the growth of P388 cells, with a 50% growth-inhibitory concentration of 44 nM. ED-110 is distinguished from camptothecin by its very different structure and its ability to intercalate into double-stranded DNA. These results suggest that ED-110 has potential as a novel antitumor agent targeting topoisomerase I.

Animals↗
PubMed1993

Purification and characterization of low molecular weight fibrinolytic/hemorrhagic enzymes from snake (Bothrops jararaca) venom.

Two low molecular weight fibrinolytic/hemorrhagic enzymes, jararafibrase III and jararafibrase IV, were purified from Bothrops jararaca venom using a fast protein liquid chromatography system. The purified jararafibrase III and jararafibrase IV were single chain proteins with molecular weights of 20,400 +/- 500 and 21,200 +/- 400, respectively, by SDS-PAGE. The isoelectric points of jararafibrase III and jararafibrase IV were 9.4 and 6.9, respectively. The activity of the enzyme was inhibited by 1,10-phenanthroline and EDTA, suggesting that both enzymes were metalloproteinases. The specific fibrinolytic activities of jararafibrase III and jararafibrase IV were 7.5 +/- 0.4 and 6.5 +/- 1.6 units/mg protein, respectively. The enzymes induced local hemorrhage in the skin of rats. The minimal hemorrhagic doses of jararafibrase III and IV were 31.0 and 34.0 micrograms/rat, respectively. The enzymes displayed broad substrate specificities like the previously purified jararafibrases I and II. Jararabrases III and IV degraded type-IV collagen, gelatin, laminin and fibronectin into smaller fragments. The specific activities of jararafibrase III for type-IV collagen and gelatin were 7.6 +/- 0.3 and 43 +/- 11 units/mg protein, respectively. The specific activities of jararafibrase IV for type IV-collagen and gelatin were 16.5 +/- 1.2 and 112 +/- 9 units/mg protein, respectively.

Animals↗
PubMed1993

Workload and cost-benefit of hospital pharmacy residents.

The workload performed by three hospital pharmacy residents during typical clinical rotations was quantified then subjected to cost-benefit analysis. Daily activities and interventions were recorded on standardized forms for a four-week period. The cost of a resident to provide direct patient care services was compared to that of a staff pharmacist. In addition, the balance of the residents' salary and partial salaries of any pharmacists spending time with the residents were included in the cost analysis. The interventions were analyzed for their impact on patient care and potential cost avoidance by an external review committee. Collectively, more than 660 hours were recorded. Fifty-two percent of hospital time was spent on education-related activities and 32 percent on the provision of clinical services. Thirty interventions were submitted to a review panel of three physicians. Of the 90 evaluations, 76 percent were considered to have a positive impact on patient care, 22 percent no effect, and two percent a potentially detrimental effect. In one case, reviewers thought that hospitalization could have been prolonged had the intervention not occurred. Cost-benefit analysis yielded a ratio of 1.4 to 1 in favour of the residents. While the major benefit of a residency program is the perceived long-term benefit to the profession and patients, this study suggests that even during their residency year, hospital pharmacy residents provide cost-beneficial clinical services.

Cost-Benefit Analysis↗
PubMed1993

[Superoxide dismutase in cerebrospinal fluid in patients with neurological diseases].

To evaluate significance of superoxide dismutase in neurological diseases, we measured cerebrospinal fluid (CSF) levels of copper-zinc superoxide dismutase (Cu/Zn SOD) and manganese superoxide dismutase (Mn SOD) using enzyme immunoassay methods in 181 neurological patients and 43 controls. The mean level of Cu/Zn SOD in CSF of controls was 54.4 +/- 28.7 ng/ml, and that of Mn SOD 8.1 +/- 2.5 ng/ml, although other methods have reported that Mn SOD is undetectable in CSF. Cu/Zn SOD or Mn SOD showed no statistical difference in age or sex of the controls. The elevation of both SOD levels was marked in acute diseases such as cerebrovascular diseases (CVD), bacterial meningitis and encephalitis, but mild in aseptic meningitis. The elevation of Cu/Zn SOD level was more prominent than that of Mn SOD in CVD, whereas vice versa in bacterial meningitis and encephalitis. In neurodegenerative diseases and cervical spondylosis, only Mn SOD level was significantly elevated. To examine the source of CSF SOD, we compared it with CSF levels of neuron-specific enolase (NSE) and S-100b protein (S-100b) in cerebral infarction and bacterial meningitis. Both SOD levels were correlated with NSE and S-100b levels in patients with cerebral infarction, but in bacterial meningitis no significant relationship was found among SOD levels, NSE and S-100b levels. This means that elevations of SODs in CSF may be due to not only damage of the nervous tissues but also the other mechanisms, as induction of SOD in the lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Photolabeled sites with a tetrodotoxin derivative in the domain III and IV of the electroplax sodium channel.

Forty three percent of the labeled sites, at least, in the electroplax sodium channel with a photoactivable tetrodotoxin derivative were identified by probing protease-digested labeled fragments with several sequence-directed antibodies. They are located in the loop between segments S5 and S6 of domain IV, as well as the region containing transmembrane segment S6 and adjacent extracellular and cytoplasmic sequences in domain III. No photolabeled fragments were detected in the corresponding region of domain I. These results suggest that C-11 of tetrodotoxin where the photoreactive moiety is attached orients to the region between S5 and S6 in domain III and IV. Probable orientation of the tetrodotoxin molecule in sodium channels is considered by taking together with the recent report of the site-directed mutagenesis.

Amino Acid Sequence↗
PubMed1992

Purification and characterization of two fibrinolytic enzymes from Bothrops jararaca (jararaca) venom.

Two fibrinolytic enzymes, jararafibrase I and jararafibrase II, were purified from Bothrops jararaca venom. The purified jararafibrase I and jararafibrase II ran as single protein bands on analytical polyacrylamide gel electrophoresis and had mol. wts of 47,000 +/- 2000 and 21,400 +/- 500, respectively, by SDS-polyacrylamide gel electrophoresis. The isoelectric points of jararafibrase I and jararafibrase II were 4.6 and 6.5, respectively. The specific activities of jararafibrase I and jararafibrase II were 2.2 units/mg protein and 6.3 units/mg protein, respectively. Both enzymes exhibited no detectable plasminogen activating activity. The activity of the enzymes was completely inhibited by 1,10-phenanthroline and ethylenediaminetetraacetate, suggesting that both enzymes were metalloproteinases. Jararafibrase I and jararafibrase II had single-chain protein compositions, and the amino acid sequence up to the 49th amino acid from the NH2-terminal of jararafibrase II was: Leu-Pro-Glu-His-Gln-Arg-Tyr-Ile-Glu-Leu-Phe-Ile-Val-Val-Asp-His-Gly-Met- Phe-Met-Lys-Tyr-Asn-Gly-Asn-Ser-Asp-Lys-Ile-Arg-Arg-Arg-Ile-His-Gln- Met-Val-Asn-Ile-Met-Lys-X-Ala-Tyr-Arg-Tyr-Leu-Tyr-Ile-(X = not confirmed).

Amino Acid Sequence↗
PubMed1992

Broad substrate specificity of snake venom fibrinolytic enzymes: possible role in haemorrhage.

We found previously that two fibrinolytic enzymes (jararafibrases I and II) purified from Bothrops jararaca venom displayed a haemorrhagic activity. To elucidate the mechanisms involved and the role of the enzymatic activity in haemorrhage, the enzymatic properties of the purified enzymes were examined. The substrate specificity of the enzymes was determined using type I collagen, type IV collagen, gelatin, laminin and fibronectin as substrates. The enzymes degraded type IV collagen, gelatin, laminin and fibronectin into smaller fragments, but degraded type I collagen only partially in a non-specific manner. The specific activities of jararafibrase I for type IV collagen and gelatin were 172 +/- 5 units/mg protein and 1315 +/- 177 units/mg protein, respectively. The specific activities of jararafibrase II for type IV collagen and gelatin were 9.2 +/- 0.6 units/mg protein and 143 +/- 15 units/mg protein, respectively. It was evident that the enzymes had rather broad substrate specificities and degraded basement membrane components including type IV collagen. The number of type IV collagen units of bacterial collagenase which gave the minimal haemorrhagic dose was 191.4, while the numbers of type IV collagenase units of jararafibrases I and II which gave the minimal haemorrhagic dose were 1.5 and 0.25, respectively. It is suggested that the broad substrate specificity of the enzymes is essential for inducing haemorrhage with a single enzyme.

Animals↗