Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 1,135 records · Page 63Linked to original sources

PubMedDate not supplied

Baseline features of idiopathic optic neuritis as determined by a multicenter treatment trial in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG).

BACKGROUND: An optic neuritis treatment trial was conducted at 30 clinical centers in Japan using the same protocol. Patient participation was based on: age range of 14-55 years; acute symptoms indicative of unilateral optic neuritis of unknown or demyelinating origin; visual symptoms of 14-day duration or less; relative afferent pupillary defect in affected eye; and normal or swollen optic disc of affected eye. CASES: Initially, 102 patients qualified for participation; baseline data were obtained for analysis from 70 of these patients. Demographic characteristics of Japanese patients with optic neuritis were clarified and compared with those in a US study. OBSERVATIONS: The incidence of ocular or periocular pain and the presence of periventricular plaques were noted to be lower, and the incidence of disc swelling higher, in the Japanese patients, suggesting racial differences in the characteristics of the disease. Such differences may possibly be related to the lower incidence of multiple sclerosis in Japanese patients. The results of visual function tests were virtually the same in both studies. The nonaffected eyes of more than half the patients showed abnormal mean deviation in Humphrey field analysis, as also noted in the US study. CONCLUSIONS: The baseline clinical features of optic neuritis in the Japanese patients have been defined. Some racial differences in the characteristics of the disease may exist.

Adolescent↗

PubMedDate not supplied

Lectin cytochemistry of the lacrimal sac epithelium in experimental dacryocystitis.

PURPOSE: To study the glycoconjugates in the lacrimal sac epithelium of Japanese white rabbits with experimentally induced chronic dacryocystitis. METHODS: Chronic dacryocystitis was induced by a subcutaneous injection of albumin followed by an injection of Staphylococcus aureus into the lacrimal sac. The histological appearance of the lacrimal sac was studied using the alcian blue-periodic acid-Schiff sequence. In addition, the specific binding to the lacrimal sac epithelium of Ulex europaeus agglutinin 1, Ricinus communis agglutinin 1, peanut agglutinin, and soybean agglutinin was also studied. RESULTS: Staining with alcian blue-periodic acid-Schiff sequence showed hyperplasia of the goblet cells in the inflamed lacrimal sac epithelium. Lectin cytochemistry revealed specific binding of Ulex europaeus agglutinin 1, Ricinus communis agglutinin 1, peanut agglutinin, and soybean agglutinin to the lacrimal sac epithelium. CONCLUSIONS: These results indicated that the composition of glycoconjugates in the lacrimal sac epithelium is markedly changed in dacryocystitis. There seems to be a fundamental abnormality in glycoconjugate synthesis in the chronically inflamed lacrimal sac epithelium.

Animals↗

PubMedDate not supplied

Production of human alpha-interferon in silkworm using a baculovirus vector.

Microorganisms are generally used for mass production of foreign gene products, but multicellular organisms such as plants have been proposed as an economical alternative. The silkworm may be useful in this context as it can be cultured easily and at low cost. We have therefore developed a virus vector to introduce foreign genes, for example, the gene for human alpha-interferon (IFN-alpha), into silkworms. We used the baculovirus Bombyx mori nuclear polyhedrosis virus (BmNPV) which has a large (greater than 100 kilobases, kb) double-stranded circular DNA genome within its rod-shaped capsid. Baculoviruses have been used previously as vectors for expression of beta-interferon and beta-galactosidase in established cell lines. Although BmNPV has not been used previously as an expression vector, it has an advantage over the baculovirus Autographa californica NPV in that it has a narrower host range and will not grow in wild insect pests in the field. In the present study, the polyhedrin gene encoding the major inclusion body protein of BmNPV was identified by hybridization with complementary DNA and cloned in a plasmid. For insertion of foreign genes, we constructed a recombinant plasmid carrying a polylinker linked to the promoter of the polyhedrin gene, and inserted the IFN-alpha gene into this plasmid. The resulting plasmid and the BmNPV genomic DNA were co-transfected into BM-N cells, and stable recombinant viruses isolated by plaque assay on BM-N cells. The recombinant virus replicated in silkworm larvae, which synthesized as much as 5 X 10(7) units (approximately 50 micrograms) of interferon in their haemolymph.

Amino Acid Sequence↗

PubMedDate not supplied

Perception of vowel-to-vowel transitions with different formant trajectories.

In this paper, the perceptual effects of vowel-to-vowel transitions determined by different temporal variations of model parameters which specify the shapes of the vocal tract area function are investigated. It is shown that, (a) the method of deformation of the vocal tract area function between two targets can be perceptually important and (b) conversely, within certain limits, the time course of parameters from one state to another, and the precise synchronization of two parameters is not important for the correct identification of a vowel series. These characteristics are necessary but not sufficient to prove the existence of a phonetic gesture percept.

Adult↗

PubMedDate not supplied

Neurochemical and pathological alterations following infusion of leupeptin, a protease inhibitor, into the rat brain.

It is known that proteases participate in cellular protein turnover and eliminate abnormal and potentially toxic proteins. Disturbed proteolysis may be responsible for generating the pathological features of some neurodegenerative disorders. Alzheimer disease, for instance, is the most common neurodegenerative disorder and a condition in which proteins of the cell membrane and cytoskeleton are abnormally processed and accumulated in the brain. It is of interest to investigate the effect of protease inhibitors on neurons and neurotransmitter systems in the brain. We examined neurochemical and morphological neuronal changes in the rat brain following long-term intracerebroventricular infusion of leupeptin, a potent calcium-activated protease (calpain) inhibitor. Leupeptin (5 mg) was infused into the lateral ventricle using an osmotic minipump for 14 days. We found a significant reduction of regional choline acetyltransferase activities in the hippocampus, and of somatostatin concentrations in the hypothalamus and entorhinal cortex. Moreover, leupeptin caused a wide-spread, highly significant decrease in neuropeptide-Y concentrations. Leupeptin infusion produced severe degeneration of neuronal processes in both axons and dendrites, and accumulation of electron-dense bodies in the hippocampus. The results indicate that long-term intracerebroventricular infusion of leupeptin in the rat produces neurochemical and morphological changes resembling those of some neurodegenerative disease and aging. Abnormal proteolysis caused by either reduced protease or enhanced protease inhibitor activities might play an important role in these conditions.

Animals↗

PubMedDate not supplied

Comparison of in vitro antimicrobial activity of AM-1155 with those of tosufloxacin and fleroxacin against clinical isolates of Neisseria gonorrhoeae harboring quinolone resistance alterations in GyrA and ParC.

The in vitro antimicrobial activities of AM-1155, a new fluoroquinolone, tosufloxacin and fleroxacin were tested against 55 clinical isolates of Neisseria gonorrhoeae using the agar dilution method. In our previous study, all the strains had been examined for mutations in the region corresponding to the quinolone-resistance determining region of the Escherichia coli gyrA gene and the analogous region of the parC gene, and tested for susceptibility to ciprofloxacin. In this study, the 55 isolates of N. gonorrhoeae were assigned to one of three categories based on the presence or absence of alterations in GyrA and ParC. In each category, the antimicrobial activity of AM-1155 against the isolates was compared with those of tosufloxacin and fleroxacin. The MICs of AM-1155 for 11 highly fluoroquinolone-resistant isolates with alterations in both GyrA and ParC ranged from 0.06 to 1.0 microgram/ml. The MICs inhibiting 50% (MIC50) and 90% (MIC90) of these isolates were 0.125 and 1.0 microgram/ml, respectively. The MICs of AM-1155 for 20 moderately fluoroquinolone-resistant isolates with alterations only in GyrA ranged from 0.03 to 0.25 microgram/ml (MIC50, 0.06 microgram/ml; MIC90m, 0.125 microgram/ml). The MICs of AM-1155 for 24 of the quinolone-susceptible isolates without alterations in either GyrA or ParC ranged from 0.004 to 0.03 microgram/ml (MIC50, 0.008 microgram/ml. MIC90, 0.015 microgram/ml). There were significant differences between the MIC distribution of AM-1155 and each corresponding MIC distribution of tosufloxacin and fleroxacin in these three categories to which the 55 isolates were assigned (p < 0.05). Based on the MIC90S of the tested fluoroquinolones, AM-1155 was two- and eightfold more active against the highly fluoroquinolone-resistant isolates than tosufloxacin and fleroxacin, respectively. Against the moderately fluoroquinolone-resistant isolates, AM-1155 was four- and sixteenfold more active than tosufloxacin and fleroxacin, respectively. Against the quinolone-susceptible strains, AM-1155 was also two- to fourfold more active than the other fluoroquinolones. Overall, AM-1155 exhibited more potent in vitro activity against both quinolone-resistant and quinolone-susceptible isolates of N. gonorrhoeae than tosufloxacin and fleroxacin. In ciprofloxacin treatment failures of gonorrhea at single doses of 500 mg. MICs for the causative organisms have ranged from 1.0 to 16.0 micrograms/ml. The MICs of AM-1155 for the isolates harboring quinolone resistance-associated genetic alterations, including strains exhibiting ciprofloxacin MICs of 2.0 and 8.0 micrograms/ml, still ranged from 0.03 to 1.0 microgram/mL A single-dose study in humans has demonstrated higher peak serum concentrations and longer half-lives of AM-1155, resulting in the AUC0-00 values of AM-1155, which are threefold greater than those of ciprofloxacin at the single doses of 400 and 600 mg. Because of its potent in vitro antimicrobial activity and advantageous pharmacokinetic behavior, AM-1155 may be a clinically useful agent for treating gonorrhea including that caused by quinolone-resistant strains.

Anti-Infective Agents↗

PubMedDate not supplied

Primary localized nodular tongue amyloidosis associated with Sjögren's syndrome.

We describe a case of primary localized nodular tongue amyloidosis associated with Sjögren's syndrome in a 62-year-old woman. The presence of Sjögren's syndrome was confirmed both serologically and histologically. The amyloid tumor, which was marginally excised, recurred 3 years later and was re-excised. Immunohistochemical examination revealed that the amyloid protein was of the AL (lambda-light chain) type. Infiltration of plasma cells was observed around the minor salivary glands of the tongue surrounded by amyloid. The relationship between the plasma cells and amyloid deposition is discussed.

Amyloid↗

PubMedDate not supplied

Fine needle aspiration cytology of the malignant variant of ossifying fibromyxoid tumor of soft parts: a case report.

BACKGROUND: Ossifying fibromyxoid tumor (OFMT) of soft parts is a rare, recently defined, fibroosseous neoplasm, generally regarded as clinically benign; however, one-third of cases recur locally, and several malignant examples have been reported. Fine needle aspiration (FNA) cytology of the tumor is rarely described in the literature. We provide the first cytomorphologic study of the malignant variant. CASE: A 70-year-old man presented with an intramuscular mass in the right buttock. Computed tomography revealed ossification within the mass and multiple pulmonary nodules. FNA biopsy showed round and polygonal to spindled tumor cells, arrayed singly, cordlike or in small aggregates, with scattered dense stromal fragments and a slightly myxoid background. The nuclei showed significant pleomorphism accompanied by coarse chromatin with clumping, irregular contours, and one to two distinct nucleoli. The tumor cells were recognizable as sarcoma, with no evidence of high grade malignancy. The tumor was totally excised, histopathologically confirmed as the malignant variant of OFMT of soft parts, and immunohistochemically and ultrastracturally analyzed as of neural origin. CONCLUSION: The FNA specimen revealed that the cytomorphology was consistent with the histologic features of the malignant variant of OFMT, but several characteristic histologic parameters, such as multilobular proliferation and peripherally placed mature, bony trabeculae, were not reflected in the aspirates. Although FNA cytologic findings may be of limited diagnostic utility in OFMT, radiographic evidence of calcification/ossification suggests that OFMT should be subjected to differential diagnosis with fine needle aspiration biopsy of soft tissue tumors. Additional studies will be required for further clarification.

Aged↗

PubMedDate not supplied

Freeze substitution and freeze drying for stable, long-term preservation of cytologic specimens for immunostaining.

OBJECTIVE: To develop a new method of fixing and preserving cytologic specimens for immunostaining after long-term storage at room temperature. STUDY DESIGN: The method consists of three steps: fixation, freeze substitution or freeze drying, and storage. To test the method, we used the human small cell lung carcinoma cell line Lu-135, which expresses a high level of mutant p53 protein and exhibits strong nuclear staining when reacted with an anti-p53 antibody. A smear of Lu-135 cells was fixed in a mixture of methanol and ether (50:50=vol/vol) or sprayed with a fixative containing isopropyl alcohol, methanol and polyethylene glycol. The fixed cells were freeze substituted by immersing them in a dry ice/methanol/ether bath and then were freeze dried under a vacuum. The smear was then placed in a 50-mL conical tube containing silica gel. The tube was sealed and stored at room temperature. RESULTS: Freeze substituted cells that were fixed with methanol/ether and stored for more than six months retained strong p53 positivity, as strong as that of the control cells, which had been fixed and stored in methanol. CONCLUSION: Freeze substitution and freeze drying are an alternative method of preserving cytologic specimens.

Carcinoma, Small Cell↗

PubMedDate not supplied