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Biomedical subjects

S Terada

Publications and source records attributed to S Terada.

At least 91 records · Page 5Linked to original sources
PubMed1995

Eradication of contaminating Mycobacterium chelonae from bronchofibrescopes and an automated bronchoscope disinfection machine.

The results of a follow-up study concerning the decontamination of Mycobacterium chelonae subspecies abscessus from the bronchofibrescopes and the automated bronchoscope disinfection machine are described in this paper. After modification of the methods for disinfecting the bronchofibrescopes (adding a disinfection procedure with 70% alcohol before using the automated bronchoscope disinfection machine, increasing glutaraldehyde concentration to 3%, and changing the glutaraldehyde solution once a week), and the automated bronchoscope disinfection machine (recirculating used disinfectant), M. chelonae has not been detected from either the bronchofibrescopes or the automated bronchoscope disinfection machine (examined every 6 months for 4 yr by microscopy and cultures). Moreover, no M. chelonae has been clinically detected from bronchial washings for 4 yr.

Bronchoalveolar Lavage Fluid↗
PubMed1995

Synapsin I deficiency results in the structural change in the presynaptic terminals in the murine nervous system.

Synapsin I is one of the major synaptic vesicle-associated proteins. Previous experiments implicated its crucial role in synaptogenesis and transmitter release. To better define the role of synapsin I in vivo, we used gene targeting to disrupt the murine synapsin I gene. Mutant mice lacking synapsin I appeared to develop normally and did not have gross anatomical abnormalities. However, when we examined the presynaptic structure of the hippocampal CA3 field in detail, we found that the sizes of mossy fiber giant terminals were significantly smaller, the number of synaptic vesicles became reduced, and the presynaptic structures altered, although the mossy fiber long-term potentiation remained intact. These results suggest significant contribution of synapsin I to the formation and maintenance of the presynaptic structure.

Animals↗
PubMed1995

Male reproductive toxicity study of nitrazepam in rats.

The main focus of this study is the optimal administration period concerning toxic effects on male fertility in rats. To assess functional and morphological changes induced in the testis by nitrazepam, male rats were administered the drug at doses of 0, 20, 40 or 80 mg/kg during pre-mating periods of 2, 4 or 9 weeks and then the 2 weeks of mating. At the end of the administration period the animals were sacrificed and sperm number, motility, abnormalities and histopathological changes in the testis were examined. Decreases in testis weight, epididymis weight, number of sperm in the testis and sperm motility were observed in the 40 and 80 mg/kg sections of the 2, 4 and 9 week pre-mating treated groups. Mating with untreated females revealed no adverse effects on copulation rate in any group; however, a remarkable decrease in pregnancy rate was noted in the 80 mg/kg section of the 2, 4 and 9 week treated groups. On histological examination, various degrees of localized necrosis in the seminiferous epithelium and Leydig cell hyperplasia were observed in the testis. No clear changes were observed in the 20 mg/kg section of the 2 week pre-mating administration group, but at the 4 week time point, necrosis of spermatogenic cells began to appear. The primary morphological event was evident in spermatocytes with necrosis of the cytoplasm observed from 4 weeks after administration of nitrazepam, although sperm motility and sperm head counts were unaffected. From these findings, examination of sperm characteristics and histopathological changes in the testis are important parameters for evaluation of drugs inducing testicular damage. We conclude that a 4 week administration period is sufficient to detect effects of nitrazepam on male fertility.

Animals↗
PubMed1995

[Effect of sex steroids on serum amyloid P-component (female protein) in rats].

Serum amyloid P-component (SAP) has been designated as a female protein in hamsters. But such a distinction is not made for rats. In order to investigate the effects of sex-steroids on the SAP level in rats, SAP was purified from Wistar rats by affinity chromatography of phosphorylcholine, followed by gel filtration. Anti-SAP was raised through the immunization of rabbits with the rat SAP and Freund's adjuvant. Sample sera were obtained from 180 young and old rats, after which rats were injected with estradiol (E2), testosterone (T) or dehydroepiandrosterone (DHEA). Sera were serially obtained from the tail vessels until the 8th day after injection. The SAP level was assayed by micro single radial immunodiffusion. As the rats aged, the SAP levels increased from 2.9 mg/dl at 11 weeks to 10.7mg/dl at 58 weeks. In 37-week-old rats, the SAP levels in females (6.3 +/- 1.8 mg/dl) were significantly (p < 0.001) higher than those in males (3.9 +/- 1.0 mg/dl). The SAP levels did not change after T administration, but were increased rapidly by E2 administration, especially in young male rats (increased from 2.6 +/- 0.2 mg/dl to 4.9 +/- 0.7 mg/dl). The SAP levels were decreased significantly (p < 0.05) by DHEA injection. Serum E2 levels in young (11 wk) male rats were very low before E2 injection, and rose steeply on the 2nd day. From these findings, the different SAP levels in mature female and male rats are attributed to E2.

Aging↗
PubMed1994

Altered microtubule organization in small-calibre axons of mice lacking tau protein.

The tau gene encodes a protein (Tau) that is a major neuronal microtubule-associated protein localized mostly in axons. It has microtubule-binding and tubulin-polymerizing activity in vitro and is thought to make short crossbridges between axonal microtubules. Further, tau-transfected non-neuronal cells extend long axon-like processes in which microtubule bundles resembling those in axons are formed. In contrast, tau antisense oligonucleotides selectively suppress axonal elongation in cultured neurons. Thus tau is thought to be essential for neuronal cell morphogenesis, especially axonal elongation and maintenance. To test this hypothesis, we used gene targeting to produce mice lacking the tau gene. We show that the nervous system of tau-deficient mice appears to be normal immunohistologically. Furthermore, axonal elongation is not affected in cultured neurons. But in some small-calibre axons, microtubule stability is decreased and microtubule organization is significantly changed. We observed an increase in microtubule-associated protein 1A which may compensate for the functions of tau in large-calibre axons. Our results argue against the suggested role of tau in axonal elongation but confirm that it is crucial in the stabilization and organization of axonal microtubules in a certain type of axon.

Animals↗
PubMed1994

Purification and characterization of two Kunitz family subtilisin inhibitors from seeds of Canavalia lineata.

Two subtilisin inhibitors (CLSI-II and -III) were purified from seeds of Canavalia lineata by extraction with water, ammonium sulfate precipitation, and chromatographies on DEAE-Toyopearl and hydroxyapatite. The two inhibitors have the same molecular weight of about 22,000, and quite similar amino acid compositions. They contain five half-cystine residues and tend to dimerize through an intermolecular disulfide bridge due to the presence of a single cysteine residue. CLSI-III only inhibited subtilisin-type serine proteases, while CLSI-II showed a wider inhibitory specificity. Though the two inhibitors have almost identical thermal labilities, CLSI-II is more stable as to extreme pH than CLSI-III. They are considered to be Kunitz type inhibitors on the basis of several properties.

Amino Acid Sequence↗
PubMed1994

Amino acid sequences of Kunitz family subtilisin inhibitors from seeds of Canavalia lineata.

The amino acid sequences of two subtilisin inhibitors (CLSI-II and -III) from Canavalia lineata seeds were determined by manual Edman degradation using the DABITC/PITC double coupling method after enzymatic digestions and CNBr degradation. CLSI-II and -III consist of 190 and 183 amino acids, respectively, and have identical amino acid sequences except for in the C-terminal regions: an elongated sequence, Gly-Thr-Ile-Arg- Ser-Asp-Gly, was found at the C-terminus of CLSI-II. A short-chain analog protein without an N-terminal Asn residue was also detected in each inhibitor preparation. The inhibitors showed significant homology to Kunitz type inhibitors, but differed from them with respect to the half-cystine content. Among five half-cystine residues present in CLSI-III, two disulfide bonds link Cys44 to Cys88 and Cys142 to Cys149, Cys106 being present as a free cysteine residue. Phenylglyoxal treatment abolished the inhibitory activity of CLSI-III, indicating the participation of an Arg residue in the interaction with the enzyme. The reactive-site peptide bond was deduced to be Arg68-Gly69.

Amino Acid Sequence↗
PubMed1994

Property and amino acid sequence of a subtilisin inhibitor from seeds of beach canavalia (Canavalia lineata).

A subtilisin inhibitor was purified from the seeds of Canavalia lineata by ammonium sulfate precipitation, ultrafiltration on a YM-30 membrane, column chromatography on DEAE-Toyopearl and SP-Toyopearl, followed by reverse-phase HPLC. The inhibitor (CLSI-I) is a low molecular weight protein (M(r) about 6500) containing no half-cystine residue, and quite stable as to extreme heat and pH treatment. CLSI-I inhibited subtilisin-type serine proteases including S. griseus alkaline protease. The amino acids of CLSI-I were sequenced by manual Edman degradation after enzymatic digestion with Achromobacter lyticus lysyl endopeptidase and Staphylococcus aureus V8 protease. CLSI-I contains 65 amino acid residues and showed a high homology to potato inhibitor I family proteins.

Amino Acid Sequence↗
PubMed1994

Purification and characterization of three proteinase inhibitors from Canavalia lineata seeds.

Three proteinase inhibitors (CLTI-I, -II and -III) were purified from the seeds of Canavalia lineata by DEAE-Toyopearl, hydroxyapatite, and anhydrotrypsin-Sepharose column chromatographies. All the inhibitors bound to trypsin at a 1:1 molar ratio and inhibited the enzyme with dissociation constants of 3-7 x 10(-9) M. They also showed the inhibitory activities on chymotrypsin. CTLI-I and -II had an identical M(r) of 8000 and very close isoelectric points (4.57 and 4.50), and existed mainly as trimers under physiological conditions. The high content of half-cystine residues and the high stability to pH and heat have suggested that these are Bowman-Birk type inhibitors. On the other hand, CLTI-III, with an M(r) of 20,500 was classified as a Kunitz (soybean) family inhibitor on the basis of the amino acid composition as well as the homology of its N-terminal 17 residues to other Kunitz inhibitors.

Amino Acid Sequence↗
PubMed1994

Amino acid sequences of double-headed proteinase inhibitors from the seeds of Canavalia lineata.

The amino acids of two Bowman-Birk type proteinase inhibitors (CLTI-I and -II) from the seeds of Canavalia lineata were sequenced by a manual Edman degradation using the DABITC/PITC double coupling method after enzymatic digestions with Achromobacter lyticus lysyl endopeptidase, Staphylococcus aureus V8 protease, and chymotrypsin. CLTI-I contains 75 amino acid residues. CLTI-II has an identical sequence to CLTI-I except an extra Asp residue attached at the C-terminus. The inhibitors showed a homology (40-70%) to other Bowman-Birk inhibitors. The reactive-site peptide bonds were estimated to be Lys21-Ser22 and Leu48-Ser49 against trypsin and chymotrypsin, respectively. An inhibitory active fragment containing only the chymotrypsin-reactive site was also described.

Amino Acid Sequence↗
PubMed1994

Gastric mucosal injury: microcirculation and Helicobacter pylori.

The integrity of gastric mucosa is well-balanced by an array of defensive mechanisms which protect the mucosa against external aggressive factors. When excessive stimulation of autonomic nervous system (irritation) is induced, microcirculatory disturbances easily lead to the gastric mucosal damage due to the formation of vasoactive mediators and oxygen radicals. In this review, our discussion has been focused on the co-ordinating function of the autonomic nervous system as well as the microcirculation as an important defense bastion. In this context, Helicobacter pylori represents an important pathogenic factor. In particular, we have discussed the contribution of monochloramine, and active oxidant, which is formed by neutrophils in the presence of ammonia derived from H. pylori to the gastric mucosal injury. Microcirculatory disturbances may be also involved in the pathogenesis of H. pylori-induced mucosal injury. On the basis of these considerations, we should not depend solely on the use of anti-acid secretory drugs for the treatment of gastric mucosal injury, but also should be aware of beneficial effect of mucosal protective drugs which may act on microcirculation and the autonomic nervous system.

Animals↗
PubMed1994

[Inverted papillomas in the nose and paranasal sinuses].

Inverted papillomas in the nose and/or paranasal sinuses exhibit a high recurrence rate, and an association with malignancy. Early diagnosis and aggressive surgical therapy are thus essential. Seventeen cases of inverted papilloma seen at Saitama Cancer Center over a 17-year period were reviewed. Common presenting symptoms, the primary papilloma sites and the results of surgical treatment were as follows. 1) Almost all patients complained of nasal obstruction. The usefulness of nasal biopsy of the tumor was confirmed, with 12 cases being diagnosed as having inverted papilloma pre-operatively. Inverted papilloma without squamous cell carcinoma caused osseous thinning, but did not destroy the bone. 2) It was found that the primary site of the papilloma involved the lateral wall of the nasal cavity. Lateral Rhinotomy was therefore recommended as a standard treatment. 3) The recurrence rate was 1/12 after Lateral Rhinotomy. Two cases had complaints associated with the Lateral Rhinotomy, nasolacrimal duct stenosis, and a scar in the median corner of eye. 4) Only one case had concomitant squamous cell carcinoma in the nose and maxillary sinus. This patient received chemo therapy, radiation therapy and finally maxillectomy, but the inverted papilloma recurred several times. Six years later, squamous cell carcinoma recurred and lead to this patient's death.

Adult↗