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Biomedical subjects

S Kojima

Publications and source records attributed to S Kojima.

At least 523 records · Page 29Linked to original sources
PubMed1994

Effect of terbium on protease activity in pancreas of mice.

The effect of terbium (Tb) on the protease activity in pancreas of mice was studied. Administration of Tb at doses of 20 and 200 mumol/kg increased the activities of trypsin and carboxypeptidase A, but did not affect the activities of chymotrypsin and carboxypeptidase B. High Tb concentrations were found in the liver and spleen compared to the kidney and pancreas. Increases in Ca concentrations in the pancreas, kidney, and spleen after Tb administration were observed. The pancreatic slice experiments showed the increase in trypsin activity after Tb treatment and increases in trypsin and carboxypeptidase A after Ca treatment. Tb inhibited strongly the activities of authentic chymotrypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Tb administration results from the activation of trypsinogen by Tb and Ca ions and that the increase in carboxypeptidase A activity is due to the activation of procarboxypeptidase A by trypsin and Ca ion, which increased after Tb administration.

Amino Acid Sequence↗
PubMed1994

[Involuntary movements caused by thalamic lesion].

We described two types of involuntary movement accompanied with a well-located thalmaic lesion shown by MR imaging in five patients. All patients had the involuntary movements of an upper limb contralateral to the thalamic lesion. Two patients (1 and 2) had choreoathetosis that became most prominent when their index finger approached their nose, where irregular and dysynchronous oscillation occasionally superimposed. This choreoathetosis was differentiated from pseudoathetosis caused by disturbance of proprioceptive sensations. The MRI lesion was located at the middle level of thalamus including nucleus centromedianus. The other three patients (3, 4 and 5) had a regular and rhythmic oscillation in their forearm. The oscillation began to appear after their index finger reached their nose on finger-to-nose test. We considered the oscillation as a postural tremor based on its rhythmicity and regularity. Patient 4 had additional tremor in movement. Their postural tremor continued while the arm kept the position. Surface electromyogram showed the reciprocal discharges between the forearm extensor and flexor muscles with a frequency of 3 to 4 Hz. This tremor was not accentuated during limb movement toward the nose nor was coarse, and was distinguished from intention tremor described by Charcot and Dejerine. This tremor was also different from hyperkinesis volitionnelle and movement oppositionist. The "rubral tremor" differed from the tremor shown in our cases for a lack of resting tremor. The responsible lesion shown by MRI located at caudal posterior thalamus including pulvinar in patient 3, or located at the upper level of thalamus in patient 4 and case 5 that was more rostral than the lesion of the choreoathetosis cases. In cases of cerebrovascular accidents, both types of involuntary movement appeared after several months from the stroke. This delayed appearance suggests that these involuntary movements were the result not only of functional disturbance of thalamus, but of secondary repairing mechanism occurring at the lesion.

Adult↗
PubMed1994

The amino acid sequence and phosphorylation sites of a boar transition protein 1.

Boar transition protein 1 was extracted with acid from the testes, purified by chromatographies on CM-Sephadex C-25 and Sephadex G-50, and reduced and carboxymethylated. The modified protein was purified by HPLC on Nucleosil 300 7C18. The primary structure of the protein was determined by automated Edman degradation of the C-terminal peptide of the BrCN-cleaved protein and of the whole protein, and by carboxypeptidase digestion of it. The study of phosphorylation sites showed that Ser36 and Ser39 in the very conserved sequence 29-42 were partly phosphorylated, suggesting the involvement of this region in the interaction with DNA.

Amino Acid Sequence↗
PubMed1994

[Outcome of treatment protocol 8704T for childhood T cell leukemia and lymphoma].

We reported the treatment outcome of Protocol 8704T, which included repeated L-asparaginase, for childhood T cell malignancies. Fifteen cases of acute lymphoblastic leukemia (T-ALL) and 11 cases of non-Hodgkin's lymphoma (T-NHL), aged 3 to 14 yrs (median 6 yrs), were enrolled. Twelve T-ALL had mediastinal mass. Murphy's stages of T-NHL were 6 with III and 5 with IV. Types of histology consisted of 8 lymphoblastic and 3 large cell. Treatment was performed for 2 years. Observation periods were from 14 months to 78 months (median 42 months). Twenty-three achieved remission and 6 of them were transplanted with bone marrow or peripheral stem cells in the first remission. The protocol was continued in 17 cases. Fourteen of them remain in first remission, but one died of measles and 2 died of relapse. The 5-year event-free survival was 76.1% for ALL and 65.5% for NHL. In terms of histology, it was 87.5% for lymphoblastic NHL and 33.3% for large cell NHL (p = 0.19). In terms of phenotypes in ALL, it was 88.7% for ALL positive to CD2, 5 and 7, while 2 ALL positive to CD7 alone both failed. Therefore, it was shown that this treatment protocol is very effective for T-lymphoblastic leukemia and lymphoma.

Adolescent↗
PubMed1994

Extragonadal germ cell tumor of retroperitoneal origin: report of two cases.

Two cases of primary extragonadal germ cell tumor of retroperitoneal origin are reported. One was a 26-year-old man complaining of back pain. He had a large retroperitoneal tumor with lung, liver and supraclavicular lymph node metastases. He was referred to us after being treated for malignant lymphoma. The serum AFP, beta-subunit of human chorionic gonadotropin (hCG-beta), CEA and CA-19-9 were elevated. The retroperitoneal disease was treated surgically and with radiotherapy. The pathological diagnosis was that of embryonal carcinoma and teratoma. The lung, liver and supraclavicular lymph node metastases disappeared completely after two courses of cisplatin-based chemotherapy. While further chemotherapy was postponed due to myelosuppression, the disease relapsed and was resistant to subsequent therapy. The patient died twelve months after he first saw us. The second case was that of a 36-year-old man complaining of edematous legs and external genitalia. He had an extensive retroperitoneal tumor with multiple pulmonary metastases. The serum AFP level was high. Suspected of having an extragonadal germ cell tumor, he was referred to us promptly. Cisplatin-based chemotherapy coupled with resection of residual retroperitoneal and pulmonary disease resulted in complete remission. The pathological diagnosis was that of possible embryonal carcinoma. Further chemotherapy was given as scheduled, using granulocyte colony-stimulating factor. The patient has been in complete remission for two years. The chemotherapeutic regimen and surgical policy in the treatment of the two patients were essentially same. Early diagnosis, adequate initial therapy and the use of granulocyte colony-stimulating factor may be relevant to the favorable prognosis in the latter case.

Adult↗
PubMed1994

[An adult case of congenital myopathy--coexistence of nemaline rods and core-like structures].

A 42-year-old female complained of exertional dyspnea and sleep disturbance. Her face was elongated longitudinally and the hard palate was narrow and high-arched. She has slender musculature and kyphoscoliosis. She was dysphonic and could not walk on her heels. Muscles in the face, upper arm, pelvic girdle and thigh were atrophic. Muscle weakness was detected in the neck, tibialis anterior, ilipsoas and other hip muscles, and ranged between 3- and 4 by the manual muscle testing. Electromyography showed definite myogenic abnormalities in all the muscle examined. No abnormality was found on the routine examination of blood, as was the motor and sensory nerve conduction velocity. Her vital capacity was 0.91 L, i.e., 35% of the expected value, suggesting a severe restrictive respiration. The arterial blood gas analysis revealed hypoxia, hypercapnia and desaturation. The blood gas data worsened when she was asleep, because of increased hypoventilation. Muscle biopsy of the biceps brachii showed a marked variation in the muscle fiber size. The type 1 muscle fiber was predominant. Many fibers contained nemaline rods and/or core-like structures. Some fibers contained both nemaline and core-like structures. This core-like structures were not stained with NADH-TR and ATPase reactions, and about 40-100 microns in the longitudinal extension. In this context, typical central cores have not been observed in the present case. No association of nemaline rods and core-like structures in the same muscle fiber has been reported, although a close relationship of the two structures has been suggested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Investigation of nicotine-induced relaxation of circular smooth muscle of the guinea-pig gastric fundus.

A possible mechanism for the nicotine-induced relaxation of circular muscle strips of the guinea-pig gastric fundus was investigated. In the presence of atropine (0.2 microM), nicotine produced concentration-dependent relaxation with a maximum effect at 100 microM (mean pEC50 value, 4.60). The maximum relaxation due to nicotine was greatly reduced by pretreatment with tetrodotoxin (0.3 microM) or hexamethonium (10 microM), but not with metitepine (0.3 microM). Combined pretreatment with timolol (0.3 microM) and phentolamine (0.3 microM) or chemical sympathectomy by 6-hydroxydopamine pretreatment partially inhibited the nicotine-induced relaxation. alpha-Chymotrypsin (2 u/ml) which abolished the equivalent relaxation induced by vasoactive intestinal polypeptide (VIP) had no effect on nicotine-induced relaxation. NG-Nitro-L-arginine (L-NNA) and NG-Nitro-L-arginine methyl ester (L-NAME) caused a concentration-dependent inhibition of the nicotine-induced relaxation (98% inhibition at 10 microM of L-NNA), but had no effect on sodium nitroprusside- or noradrenaline-induced relaxation. The inhibitory effect of L-NNA or L-NAME was reversed completely by L-arginine (3 mM), but not by D-arginine (3 mM). From these results, we concluded that nicotine-induced relaxation of the guinea-pig gastric fundus is mediated largely by the release of nitric oxide or a related substance and partially by the release of noradrenaline. Possible contributions of 5-hydroxytryptamine or VIP to the nicotine-induced relaxation appear to be negligible.

Amino Acid Oxidoreductases↗
PubMed1993

Inhibitory effect of neopterin on NADPH-dependent superoxide-generating oxidase of rat peritoneal macrophages.

The effect of the oxidized form of neopterin (NP) on the NADPH-dependent superoxide-generating oxidase (NADPH-oxidase) was investigated in both whole-cell and cell-free activation systems by using peritoneal macrophages of rats which had received an intraperitoneal injection of mineral oil. In the whole-cell system, NP remarkably inhibited the generation of superoxides in macrophages stimulated with phorbol myristate acetate (PMA). NP also showed an significant suppression of the activation of superoxide-generating NADPH-oxidase in the cell-free system using solubilized membranes and sodium dodecyl sulfate (SDS) as a stimulant. The 50%-inhibitory concentration (IC50) of NP was about 1 microM in both assay systems. In a kinetic study, competitive inhibition of the NADPH-oxidase by NP was observed in the cell-free system with a calculated inhibition constant (Ki) of 6.50 microM. These findings suggest that NP may play an important role in the suppression of superoxide generation via the inhibition of the NADPH-oxidase in phagocytes.

Animals↗
PubMed1993

Molecular characterization of a short interspersed repetitive element from tobacco that exhibits sequence homology to specific tRNAs.

We have characterized a family of tRNA-derived short interspersed repetitive elements (SINEs) in the tobacco genome. Members of this family of SINEs, designated TS, have a composite structure and include a region structurally similar to a rabbit tRNA(Lys), a tRNA-unrelated region, and a TTG repeat of variable length at the 3' end. Southern blot hybridization, together with a search of the GenBank data base, showed that various plants belonging to the families Solanaceae and Convolvulaceae contain sequences homologous to the TS family in the introns and flanking regions of many genes, whereas Arabidopsis in the family Cruciferae and several species of monocoytledonous plants do not. The TS family is widely involved in structural and genetic variations in the genomes of many plants that belong to the order Tubiflorae. All of nine sequences identified in a data base search are truncated at their 5' regions and lack the tRNA-related region of the TS family. We characterized the entire sequence of the members of the TS family and found that this family can be categorized as a member of a group of SINEs with a tRNA(Lys)-like structure, as can several animal SINEs. The TS family can be divided into two major subfamilies by analysis of diagnostic positions, and one of the subfamilies is clearly younger than the other. Amplification of many copies of the full sequence of the younger subfamily occurred during the recent evolution of the tobacco lineage. We also discuss mechanisms that could be involved in the generation of SINEs in animals and also in plants.

Base Sequence↗
PubMed1993

Protective effects of tetrahydroneopterin against free radical-induced injury.

The therapeutic potency of 5,6,7,8-tetrahydroneopterin (NPH4) was investigated in ischemic paw edema, Adriamycin (ADR)-induced cardiotoxicity, and endotoxin [lipopolysaccharide (LPS)]- and carbon tetrachloride (CCl4)-induced hepatotoxicity in mice. Ischemic paw edema was completely suppressed by pre-administration of NPH4. ADR-induced cardiotoxicity and LPS-induced hepatotoxicity were significantly decreased by post-administration of NPH4. Furthermore, NPH4 ameliorated CCl4-induced hepatotoxicity. These results suggest that NPH4 may be useful for the treatment of free radical, especially superoxide radical, -related tissue injury.

Animals↗
PubMed1993

Bovine urokinase-type plasminogen activator and its receptor: cloning and induction by retinoic acid.

Full-length cDNAs encoding bovine urokinase-type plasminogen activator (u-PA) and urokinase receptor (u-PAR) were cloned from an aortic endothelial cell cDNA library using PCR-amplified cDNA fragments as probes. Bovine u-PA amino acid identity ranges from 79.5 to 70.9% when compared to its pig, human, baboon and mouse analogues, while bovine u-PAR is 61.8 and 59.6% identical to its human and mouse counterparts, respectively. All Cys residues previously found in mature u-PA and u-PAR from these different species are also conserved in the bovine molecules. Bovine u-PA and its cell-surface receptor display one and six potential sites of N-linked glycosylation, respectively. Northern blot hybridization demonstrated a moderate induction of u-PA and u-PAR mRNA in bovine aortic endothelial cells after treatment with 10 nM and 1 microM retinoic acid for 8 hours.

Amino Acid Sequence↗
PubMed1993

Requirement for a disulfide bridge near the reactive site of protease inhibitor SSI (Streptomyces subtilisin inhibitor) for its inhibitory action.

The problem of why serine protease inhibitors having substrate-like structure around the reactive site are not degraded by the cognate protease has prompted us to investigate the structural requirements in Streptomyces subtilisin inhibitor (SSI) for its inhibitory action. We removed the disulfide bridge between Cys71 and Cys101 near the reactive site by oligonucleotide-directed mutagenesis, replacing both Cys residues with Ser residues. Inhibitory activity of the mutated SSI toward subtilisin BPN' was initially potent, but decreased remarkably with increasing incubation time after mixing (temporary inhibition), due to degradation of the mutated SSI by subtilisin via a specific intermediate with a nick at the reactive site (Met73-Val74). Binding affinity of subtilisin for the mutated SSI was reduced by more than 10(3)-fold, and the mutated SSI showed a 20 deg.C decrease in melting temperature, which probably mainly reflects the destruction of the region of alpha-helix containing Cys101. These results imply that the susceptibility of the mutated SSI to protease, and the irreversibility of the peptide bond cleavage at the reactive site, result from increased flexibility around the reactive site in the complex of the disulfide-bond-removed SSI with the protease, demonstrating the requirement of conformational rigidity around the reactive site of the inhibitor for its native inhibitory action.

Amino Acid Sequence↗
PubMed1993

Basic fibroblast growth factor counteracts the suppressive effect of transforming growth factor-beta 1 on human myeloid progenitor cells.

We have previously shown that basic fibroblast growth factor (bFGF) is mitogenic for human bone marrow stromal cells and enhances myelopoiesis in human long-term bone marrow culture. In the present study, we examined the mechanism by which bFGF enhances granulopoiesis. We observed that bFGF significantly abrogated the inhibitory effect of transforming growth factor-beta 1 (TGF-beta 1) on granulocyte-macrophage colony-stimulating factor (GM-CSF)-supported progenitor cell growth (P = .009). The partial reversal of TGF-beta 1-mediated suppression was dependent on the dose of bFGF used. In addition, we noted that the inclusion of neutralizing antibody to TGF-beta 1 significantly augmented the clonogenic response to GM-CSF. We have also shown that 10 ng/mL or 100 ng/mL of bFGF resulted in a 30% to 100% increase in GM-CSF-mediated progenitor cell growth (P = .0001). These data suggest that bFGF may enhance myelopoiesis by modulating the inhibitory response to TGF-beta 1.

Antibodies↗