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Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 793 records · Page 44Linked to original sources

Ultrastructural visualization of elastic fibres with a tannate--metal salt method.

A modification of the tannic acid-metal salt method was applied as an ultrastructural stain for elastin. Thin sections of glutaraldehyde-fixed, embedded rat aorta and rabbit elastic cartilage, with and without osmication, were examined. Raising the pH of the tannic acid solution from 2.7 to 9.0 progressively increased the electron-density of elastic fibres and collagen fibrils in osmicated and unosmicated specimens. The maximum tannic acid staining of elastic fibres was observed in the pH range 7.0-9.0. Collagen staining, although less intense than that of elastic fibres, was also greatest in this pH range. Elastic fibres in osmicated specimens demonstrated the strongest tannic acid staining with a minimal increase in density of collagen and cell nuclei when compared to the unosmicated specimens. Sequential treatments of osmicated specimens with tannic acid pH 7.0-9.0, and uranyl acetate, pH 4.1, enhanced the density of the elastin intensely, increased collagen staining moderately, but hardly increased the density of nuclei and microfibrils. In elastase-digested osmicated specimens, all tannic acid (pH 7.0)-uranyl acetate-reactive elastin was selectively removed. These results demonstrate that all the neutral and alkaline tannic acid-uranyl acetate methods can be used as a postembedment stain for elastin specimens fixed in glutaraldehyde and osmium tetroxide.

Animals↗

Rapid focus reduction neutralization test of Japanese encephalitis virus in microtiter system. Brief report.

An improved rapid focus reduction neutralization test for Japanese encephalitis (JE) virus in microtiter system was developed. 96-well tissue culture plates were used for preparation of cell monolayers and PAP (peroxidase-antiperoxidase) staining technique was used for visualization of foci of infected cells. As the test has many advantages over other methods, it might be applied widely for rapid diagnosis and seroepidemiological studies.

Animals↗

A study of the clinical characteristics and treatment of oral carcinoma in situ.

Twelve patients with oral carcinoma in situ were examined to clarify the clinical features and the most suitable therapy for this lesion. Seven cases were classified clinically as the erythroplakic type, two as the leukoplakic type, and three as the mixed type. The cumulative survival rate of ten cases, excluding two cases with lesions of the soft palate, was 100% in 10 years. Of 12 lesions of oral carcinoma in situ 50% progressed into invasive carcinoma. Erythroplakic lesions of oral carcinoma in situ were more aggressive than the other two types. The most suitable therapy for this lesion is prompt surgical treatment.

Adult↗

Clinicopathological study of maxillary sinus carcinoma.

Autopsy was performed on 67 patients who had squamous cell carcinoma of the maxillary sinus. These patients had undergone radiotherapy and died during a 30 year period, which ended for this study in 1982. The clinicopathological picture showed several differences according to changes of the mode of therapy and to the rise in local control rate. Postmortem examinations have shown a decreased death rate from extensive carcinoma, and increased distant metastases after the introduction of megavoltage irradiation and trimodal combination therapy (radiotherapy + surgery + intraarterial infusion of antimetabolites). In addition, the introduction of aggressive chemotherapy with antimetabolites and antibiotics has given rise to several gastrointestinal complications.

Adult↗

Diagnosis of aneurysmal bone cyst of the mandible. A report of two cases with emphasis on scintigraphic approaches.

Aneurysmal bone cyst is rarely found in the mandible, and roentgenographic diagnosis of this condition is not easily made. In this report, the diagnostic value of bone scintigraphy and radionuclide angiography and CT imaging in two cases of aneurysmal bone cyst of the mandible are discussed. Bone scintigraphy with Tc-99m MDP demonstrated ring-like or doughnut-pattern accumulation of radioactivity, which corresponded to the expansile character of the bony lesion. The accumulation of radioactivity was intensive in the peripheral region despite the fact that the lesion was benign. Furthermore, the central rarefaction showed that the lesion was cystic. Radionuclide angiography with Tc-99m HSA, including blood pool scan, did not detect radioactive concentration. Thus bone scintigraphy and radionuclide angiography were found to be essential in the differential diagnosis of aneurysmal bone cyst from other forms of tumor, especially hypervascularized tumor and central hemangioma of the mandible.

Angiography↗

Nucleotide sequence and promoter region for the neutral protease gene from Bacillus stearothermophilus.

The thermostable neutral protease gene nprT of Bacillus stearothermophilus was sequenced. The DNA sequence revealed only one large open reading frame, composed of 1,644 bases and 548 amino acid residues. A Shine-Dalgarno sequence was found 9 bases upstream from the translation start site (ATG), and the deduced amino acid sequence contained a signal sequence in its amino-terminal region. The sequence of the first 14 amino acids of purified extracellular protease completely matched that deduced from the DNA sequence starting at GTC (Val), 687 bases (229 amino acids) downstream from ATG. This suggests that the protease is translated as a longer polypeptide. The amino acid sequence of the extracellular form of this protease (319 amino acids) was highly homologous to that of the thermostable neutral protease from Bacillus thermoproteolyticus but less homologous to the thermolabile neutral protease from Bacillus subtilis. A promoter region determined by S1 nuclease mapping (TTTTCC for the -35 region and TATTTT for the -10 region) was different from the conserved promoter sequences recognized by the known or factors in bacilli. However, it was very homologous to the promoter sequence of the spo0B gene from B. subtilis. The guanine-plus-cytosine content of the coding region of the nprT gene was 58 mol%, while that of the third letter of the codons was much higher (72 mol%).

Amino Acid Sequence↗

Ultrastructural visualization of carbohydrates in oxytalan fibers in monkey periodontal ligaments.

Fullmer's oxytalan fibers appear to be special connective tissue fibers belonging to elastic system fibers. We have ultrastructurally examined carbohydrates in oxytalan fibers in monkey periodontal ligaments after glutaraldehyde fixation and ethylenediaminetetraacetic acid (EDTA) decalcification using: Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for thin-section staining of vicinal glycol-containing complex carbohydrates, and the concanavalin A-ferritin (Con A-ferritin) and Con A-horseradish peroxidase (Con-A-HRP) en bloc staining methods specific for alpha-D-mannosyl and alpha-D-glucosyl groups. PA-TCH-SP stained collagen fibrils weakly to moderately and stained oxytalan fibers moderately. Con A-ferritin and Con A-HRP stained collagen fibrils weakly or moderately and stained oxytalan fibers intensely within the superficial region of specimen blocks. The penetration of staining reagents was improved by prior saponin treatment and/or chondroitinase ABC digestion. Thus, these studies demonstrate that PA-TCH-SP and Con A staining of carbohydrates is very useful in identifying oxytalan fibers at the ultrastructural level and that more carbohydrate components are present in oxytalan fibers than in collagen fibrils.

Animals↗

An immunohistochemical study of renal vascular lesions in hypertensive patients.

This study examined the immunohistochemical findings in renal arterioles from biopsy specimens, and related the findings to those of light and electron microscopy. The renal biopsy specimens were obtained from 57 normotensive patients with primary glomerular diseases or idiopathic hematuria, 14 hypertensive patients with associated primary glomerular diseases, 4 patients with essential hypertension and 1 with primary aldosteronism. The tissue slices for the immunohistochemical study were processed with FITC-labelled rabbit antihuman immunoglobulin antisera. Deposits of IgM were detected on the renal arterioles in 16 of the hypertensive patients (84%), but in only 7 of the normotensive patients (12%). The difference in incidence was significant (p less than 0.005). C3 was almost always deposited in the renal arterioles regardless of whether the patient was hypertensive or normotensive. IgG, IgA or fibrinogen were demonstrated only in a few cases, and albumin in no cases. When sections stained with horseradish peroxidase-conjugated anti-IgM antibody were compared under a light microscope with the adjacent PAS-stained sections, it was demonstrated that IgM was deposited only in the portions of the arteriolar walls which showed hyalinotic changes. Electron microscopic examination demonstrated that electron-dense deposits in the subendothelial or intercellular spaces of arteriolar walls were more frequent in the hypertensive patients (11 of 14 cases, 79%) than in the normotensive patients (5 of 18 cases, 28%, p less than 0.05). The deposits appeared to be similar to those which are often found in the glomeruli of patients with glomerulonephritis and which are considered to be immune complexes. These findings suggest that some immunologic mechanism mediated by IgM antibody might be a factor in the development of hypertensive vascular lesions.

Adolescent↗

[Laboratory and clinical studies of cefminox in the pediatric field].

The authors have carried out the pharmacokinetic and clinical studies of cefminox (CMNX, MT-141). The results were as follows: CMNX was given by intravenous drip infusion for 1 hour at a dose of 20 mg/kg b.w. to 2 children. The serum levels of CMNX were 103.02 micrograms/ml and 77.73 micrograms/ml at 1 hour after drip infusion, and the levels at 7 hours were 4.39 micrograms/ml and 4.19 micrograms/ml, respectively. The half life times were 1.20 hours and 1.32 hours, respectively. CSF concentrations of CMNX at 1 hour after drip infusion of a dose of 50 mg/kg in 3 patients with aseptic meningitis were 1.68 micrograms/ml (d.i. for 30 minutes), less than or equal to 0.25 micrograms/ml (d.i. for 1 hour) and 0.51 micrograms/ml (d.i. for 1 hour), respectively. CSF/serum ratios were 1.1% and 0.6%. Clinical efficacy was evaluated in 10 cases with purulent tonsillitis (3 cases), pneumonia (3 cases), pyelonephritis (1 case) and enteritis (3 cases). Excellent and good responses were obtained in all cases. Bacteriological response in the form of eradication was noted 8 of 9 cases. No side effects were observed.

Anti-Bacterial Agents↗

[Clinical and laboratory evaluation of aspoxicillin in the pediatric field].

The authors have carried out the clinical and laboratory evaluation of aspoxicillin (ASPC, TA-058). The results were as follows: Antibacterial activities The susceptibility to ASPC was estimated by plate dilution method on 26 strains each of S. aureus, E. coli, Salmonella and P. aeruginosa and 19 strains of S. marcescens isolated from clinical specimens. Minimum inhibitory concentration (MIC) of ASPC against E. coli and Salmonella was about twice active to compare with ampicillin (ABPC), but MIC of ASPC against S. aureus was two-fold less active than that of ABPC. Antimicrobial activities of ASPC against S. marcescens were similar to that of ABPC, while against P. aeruginosa its activities were two-fold higher than that of carbenicillin. Serum levels and urinary excretions When ASPC was administered at 20 mg/kg by one shot intravenous injection, serum concentration was 75 micrograms/ml after 15 minutes and half-life (T 1/2 beta) was 1.65 hours. Urinary excretion within 6 hours after ASPC injection reached to 245.6 mg (26.1%). The reason of this law urinary excretion rate was due to the underlying disease (hydronephrosis). In case of 20 mg/kg administration of ASPC by intravenous drip infusion, peak serum level reached to 88 micrograms/ml at the end of injection, and half-life (T 1/2 beta) was 0.77 hour. Since ASPC degradation by beta-lactamase was proceeded, urinary excretion of this case was not measured by microbiological method. Penicillonic acid and its epimer were detected by HPLC method. It was found that beta-lactamase producing strain was S. marcescens which was isolated by urine culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Amoxicillin↗

[Basic and clinical studies of ceftizoxime suppositories in the pediatric field].

A bacteriological and clinical study of ceftizoxime suppositories (CZX-S) let to the following results. The CZX serum concentration 10 minutes after insertion of one 250 mg suppository (i.e. 5.7-15.2 mg CZX per kg body weight) ranged from 1.64 to 6.53 micrograms/ml (average: 4.41 micrograms/ml). In one child the concentration 7 minutes after insertion was 4.13 micrograms/ml. Therapeutic responsiveness was recorded as "effective" in 8 (88.9%) of the 9 children who were broken down into 6 with tonsillitis, 1 with pharyngitis, and 2 with UTI. Bacteriological studies conducted in 5 children have confirmed eradication in 4 children, one of whom showing appearance of another strain. The rate of discharge of the suppository within 10 minutes after insertion was 20.4%. Reddening and erosion of the anus were observed in 1 child.

Adolescent↗

[Laboratory and clinical studies on SM-4300 in the pediatric field].

The authors have carried out the laboratory and clinical studies of SM-4300 and obtained the following results. Serum level of IgG before and after administration of SM-4300 was observed in a case with agammaglobulinemia. The serum level reached the peak at 30 minutes after administration of SM-4300 and the half-life was about 25 days. SM-4300 enhanced the opsonic activity of human neutrophils to Pseudomonas aeruginosa in vitro. In substitution therapy against agammaglobulinemia, the clinical effect of SM-4300 was observed. Four patients with severe infections were treated with SM-4300 and antibiotics and evaluated. Clinical effects of SM-4300 in combination therapy with antibiotics were excellent in 2 cases, good in 1 case and poor in 1 case. The subjective and objective clinical side effects and abnormal laboratory findings were not noted.

Agammaglobulinemia↗