Biomedical subjects

Y Toda

Publications and source records attributed to Y Toda.

At least 19 recordsLinked to original sources

PubMed1992

Immunoelectron microscopic studies of glycosaminoglycans in the metaphyseal bone trabeculae of growing rats.

The types and distribution of glycosaminoglycans (GAGs) were studied immunocytochemically in osteoid, mineralized bone matrix, and cartilage matrix of growing rat metaphyseal bone after aldehyde fixation and EDTA demineralization, using four monoclonal antibodies (mAbs 1-B-5, 2-B-6, 3-B-3 and 5-D-4). These mAbs specifically recognize epitopes in non-sulphated chondroitin (C0-S); chondroitin 4-sulphate (C4-S) and dermatan sulphate (DS); chondroitin 6-sulphate (C6-S) and C0-S; and keratan sulphate (KS) respectively. In osteoid, all mAbs except 1-B-5 weakly stained matrix material on and between collagen fibrils, and moderately stained organic material corresponding to bone nodules, which are known sites of mineralization. However, the staining of osteoid abruptly decreased at the mineralization front; weak staining was confined mostly to the organic material of bone nodules in mineralized bone matrix, with very weak or no staining of the rest of the bone matrix. This staining progressively decreased toward the mineralized cartilage matrix and became negative. The mineralized cartilage matrix and lamina limitans reacted strongly with all mAbs except 5-D-4. These results indicate that osteoid contains sulphated proteoglycans containing C4-S and/or DS, C6-S and KS, and subsequent bone matrix mineralization appears to require accumulation of these macromolecules within bone nodules and eventual loss of these substances for complete mineralization, whereas proteoglycans containing C0-S, C4-S and/or DS, and C6-S still exist in mineralized cartilage matrix and lamina limitans.

Animals↗

PubMed1992

Structural determination of gangliosides that bind to influenza A, B, and C viruses by an improved binding assay: strain-specific receptor epitopes in sialo-sugar chains.

An improved binding assay for detection of ganglioside receptors for influenza A, B, and C viruses was developed. In this system, the virions bound to gangliosides that were developed on a silica gel thin-layer plate were detected by mouse monoclonal antibody against viral hemagglutinin and peroxidase-conjugated anti-mouse immunoglobin. No hydrolysis of the gangliosides by viral receptor-destroying enzyme was detected in the present condition. The reactivity of the viruses to gangliosides depended on the amount of developed gangliosides (10 pmols-10 nmols), the molecular species of sialic acid, and their sugar sequences. Human influenza A (PR/8/34), B (Lee/40), and C (Ann Arbor/1/50) viruses bound different receptor epitopes of sialo-sugar chains of gangliosides. The A/PR/8 virus bound most effectively to Neu5Ac-containing lacto-series gangliosides carrying type I and type II sugar chains, followed by ganglio-series and hematoside-series gangliosides. The A/PR/8 virus weakly bound to Neu5Ac alpha 2,6lactotetraosylceramide [IV6(Neu5Ac)Lc4Cer] and Neu5Ac alpha 2,6paragloboside [IV6(Neu5Ac)nLc4Cer] carrying Neu5Ac alpha 2,6Gal sequence, although their Neu5Ac alpha 2,3Gal derivatives were the most potent gangliosides tested. B/Lee/40 bound restrictively to IV6(Neu5Ac)Lc4Cer and IV6(Neu5Ac)nLc4Cer, which carry Neu5Ac alpha 2,6Gal sequence, and type I and type II lacto-series sugar chain, respectively. C/Ann Arbor/1/50 reacted only with 9-O-Ac-Neu5Ac-carrying sugar chains in all the gangliosides tested. This method also allowed the microanalysis of receptor gangliosides of unknown samples. ESK cells, sensitive to the influenza A viruses infection, expressed several kinds of receptor active gangliosides, while those from ESK-R cells, resistant to the virus infection, were undetectable.

Binding Sites↗

PubMed1992

Siblings of 21-hydroxylase deficiency (non-salt-losing) with aldosterone hypersecretion.

We describe siblings with the non-salt-losing form of 21-hydroxylase deficiency who had hypersecretion of aldosterone and plasma renin activity (PRA). Blood pressure and serum electrolytes in both cases were normal despite the aldosterone hypersecretion. Aldosterone secretion was elevated markedly with ACTH administration and with sodium deprivation and/or volume depletion during ACTH suppression by dexamethasone. With suppression by dexamethasone, aldosterone hypersecretion was decreased with lowering of the steroids proximal to the block in the biosynthetic pathway. However, urinary sodium excretion was decreased. These results suggest that the biosynthetic pathway for aldosterone production was preserved. Furthermore, aldosterone hypersecretion and high PRA may serve to compensate for the sodium loss which results in turn from the overproduction of the sodium-losing steroids, such as progesterone and 17 alpha-hydroxyprogesterone which are aldosterone antagonists.

Adolescent↗

PubMed1992

Studies on viridenomycin, a novel 24-membered macrocyclic polyene lactam antibiotic.

A new antitumor antibiotic, designated AL081, was obtained from the culture filtrate of an actinomycete identified as Streptomyces gannmycicus, and found to be identical with viridenomycin by direct comparison. The structure of the antibiotic was determined by NMR spectral analysis including a variety of two-dimensional techniques to be a novel 24-membered macrocyclic polyene lactam. Viridenomycin prolonged the survival periods of mice bearing P388 leukemia and B16 melanoma cells.

Animals↗

PubMed1992

[The effect of anesthetic agents on descending spinal cord evoked potential and the compound muscle action potentials elicited by stimulation at the cerebral motor cortex and the spinal cord].

Recently, intraoperative monitoring of the motor tract by descending spinal cord motor evoked potentials (MEP) and compound muscle action potentials (CMAP) has been applied in clinical testing. Since several reports have mentioned the vulnerability of these potentials to anesthetic agents, experimental studies were carried out on the relationship between these potentials and anesthesia using 41 adult cats. The effects of anesthesia on changes in amplitude of the direct wave (D wave) and indirect wave (I wave) of the MEP and CMAPs were investigated. These potentials were generated by stimulation of the spinal cord and the motor cortex, respectively. Enflurane (2%), halothane (1%) and isoflurane (1.5%) with pure oxygen decreased the amplitude of the I wave to less than 50% of the control level. The CMAP after stimulation of the spinal cord was degraded to less than 30%, and the CMAP after cortical stimulation vanished completely. Only the D wave was stable against inhalational anesthetic agents. Sixty-seven percent nitrous oxide with the above concentrations of these inhalational anesthetic agents decreased the amplitude of the I wave to less than 30% and the CMAP evoked by spinal cord stimulation vanished. The effect of modified NLA (diazepam and pentazocine) on these potentials was weaker than that of the inhalational anesthetic agents.

Action Potentials↗

PubMed1991

Impairment of bone formation with aluminum and ferric nitrilotriacetate complexes.

The deleterious effects of aluminum(AL) and iron(Fe) on bone formation were studied in the presence of nitrilotriacetate (NTA) as a chelator. Both Al-NTA (1.0-1.5 mg Al/kg/day, n = 12)- and ferric nitrilotriacetate (Fe-NTA) (2.0 mg/kg/day, n = 4)-treated Wistar rats showed renal insufficiency blood urea nitrogen [BUN] levels of 25 +/- 8.8-20 +/- 0.7 compared to 12 +/- 0.7-11 +/- 0.4 mg/dl), osteomalacia with a relative osteoid volume of 31.5 +/- 5.6-13.2 +/- 2.4 compared to 4.6 +/- 1.8-0.83 +/- 0.12%, and bone growth retardation (3.1 +/- 0-3.0 +/- 0.2 compared to 3.4 +/- 0-3.3 +/- 0.1 cm) in 24 control rats. Dietary vitamin E(VE) supplementation prevented the Fe-NTA-induced impairment, but not the Al-NTA toxicity. Aluminum was deposited at the interface between osteoid and mineralized bone, while Fe was deposited in the osteoblasts and osteoclasts. There seems to be a positive correlation between hypophosphatemia and osteomalacia but carboxy-terminal parathyroid hormone (C-PTH) and calcium (Ca) levels in the serum were not related to the degree of osteomalacia. Administration of Al-NTA results in more bone Al deposition than that of aluminum chloride (AlCl3) (450 +/- 40 compared to 211 +/- 18 mg/kg fat-free dry weight). The Fe-NTA bone change is related to VE-preventable cellular injury, being consistent with the notion that Fe-NTA toxicity is caused by lipid peroxidation. Al-NTA can be used as an animal model of renal osteodystrophy. Osteodystrophy by Al in chronic renal failure may be mediated by the intrinsic chelator or chelating substance(s) retained in the body fluid due to renal insufficiency.

Aluminum↗

PubMed1991

Distribution and immunochemical specificities of fimbriae of Porphyromonas gingivalis and related bacterial species.

Rabbit polyclonal antibody (Poly-1) and mouse monoclonal antibodies (mAbs) TO-11, TO-14 and TO-M1 specific for Porphyromonas gingivalis 381 fimbriae were prepared. Poly-1 and the 3 mAbs were screened for their reactivity with whole cells oral and nonoral black-pigmented bacterial species by enzyme-linked immunosorbent assay (ELISA) and the binding experiment using [125I]Poly-1 and [125I]mAbs. ELISA revealed that Poly-1 definitely reacted with whole cells of all the 11 strains of P. gingivalis tested. However, 8 of 11 P. gingivalis strains reacted with mAbs TO-11, TO-14 and TO-M1. These results were confirmed by the specific binding of radiolabelled Poly-1 and mAb TO-11 to the 8 strains. The M(r) of the fimbrial subunit protein (fimbrilin) isolated and purified from P. gingivalis strains 381, BH18/10, HW24D-1, 6/26 and OMZ 314 was 41 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis. It was found by immunoblotting that mAbs TO-11 and TO-14/TO-M1 recognized different epitopes of fimbrial protein from P. gingivalis strains. Immunoelectron micrographs of whole cells and the purified fimbriae of P. gingivalis strains visualized similar serotype-specific antibody bindings to the fimbriae. These results indicate that 11 strains of P. gingivalis could be divided into at least 2 separate groups based on the immunochemical specificities of the fimbriae.

Animals↗

PubMed1991

Effects of color CRT display on pupil size in color-blind subjects.

The effects of color cathode ray tube (CRT) display on the pupil size in color-blind subjects were studied experimentally. Red, magenta, green, cyan, yellow, and white were presented on the CRT. Five protan subjects, five deutans, and five normal subjects were tested using infrared pupillography. In the protan group, the pupils were significantly less sensitive to red (wavelength: 600 nm) targets compared to the other colors. In the deutans and the control group, there were non-significant changes in pupil size in response to the colors. Dominant wavelengths above 600 nm in color CRTs should be avoided in routine work presentation because of less sensitivity in protanopias.

Adult↗

PubMed1991

[Study of prognostic factors of survival in patients with unresectable non-small cell lung cancer].

We studied prognostic factors of survival in 121 patients unresectable non-small cell lung cancer treated between March 1983 and November 1988 at forth department of internal medicine, Kinki university school of medicine, about histology, clinical stage, age, sex, performance status, Brinkman Index, hemoglobin, serum TP, serum Alb, serum LDH, pulmonary function and chemotherapy. The prognostic factors were studied using survival rate by Kaplan-Meier method, univariate analysis by Log-rank test and generalized Wilcoxon test and multivariate analysis by proportional hazard model of Cox. The prognostic factors of pretreatment were age, serum Alb, serum LDH, pulmonary dysfunction of mixed type and performance status. In the classified study according to histology, age and pulmonary dysfunction of mixed type were prognostic importance in patients with squamous cell lung cancer. Hemoglobin in patients with squamous cell lung cancer was important, too. The chemotherapy given good response improved patient's prognosis.

Adenocarcinoma↗

PubMed1990

A new depsipeptide antibiotic, citropeptin.

An actinomycete identified as Streptomyces flavidovirens was found to produce a new cyclic hexadepsipeptide antibiotic, designated citropeptin. Citropeptin showed antitumor activity against P388 murine leukemia.

Animals↗

PubMed1979