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Biomedical subjects

S Kondo

Publications and source records attributed to S Kondo.

At least 919 records · Page 51Linked to original sources
PubMed1989

Chemotaxonomic study of Vibrio cholerae bio-serogroup Hakata on the basis of the sugar composition of the polysaccharide portion of its lipopolysaccharides.

A chemotaxonomic study was carried out on 31 strains of non-O1 Vibrio cholerae bio-serogroup Hakata, isolated in Japan, which possesses the Inaba antigen C of O1 V. cholerae. On the basis of the compositional sugar pattern of the polysaccharide portion of their lipopolysaccharides, the 23 strains isolated from the environment were separated into two groups, one (20 strains) containing mannose, glucose, fructose, L-glycero-D-mannoheptose, glucosamine, perosamine, quinovosamine, and an unidentified amino sugar AS, and the other (3 strains) containing two additional sugars, galactose and a trace amount of galactosamine. All of the eight strains isolated from imported seafoods belonged to the former group.

Animals↗
PubMed1989

Studies of a glomerular permeability factor in patients with minimal-change nephrotic syndrome.

Peripheral blood mononuclear cells (PBMC) from patients with minimal-change nephrotic syndrome (MCNS) were tested for their ability to produce a factor which increases the urinary protein excretion levels of rats. It was shown that enhanced proteinuria can be produced in 8-hour urine specimens from rats by the injection of concentrated supernatants of cultured concanavalin-A-stimulated PBMC of patients with MCNS, but not from other nephrotics or normal subjects. The increase in urinary protein excretion was associated with a significant alteration of glomerular epithelial cells similar to that seen in MCNS. These results suggest that in MCNS, PBMC release a factor, which we termed a glomerular permeability factor (GPF), causing changes in glomerular permeability with resulting proteinuria.

Adolescent↗
PubMed1989

Characterization of autonomic receptors in neonatal urinary tract smooth muscle.

In the 1-day-old rabbit there are a large number of alpha-2- (labeled with [3H]yohimbine) than alpha-1- (labeled with [3H]prazosin) adrenergic receptors in the various parts of urinary tract smooth muscle, but the alpha-1 receptors are functionally more responsive to agonists than are the alpha-2 receptors. Unlike the findings in the adult rabbit, the neonatal bladder dome is functionally more sensitive to alpha-adrenergic agonists than the neonatal bladder base. The rank order of beta-adrenergic receptor densities (labeled with [3H]dihydroalprenolol) in various urinary tract smooth muscles correlates with the magnitude of the relaxant response to isoproterenol. There is a high number of functional muscarinic receptors (labeled with [3H]quinuclidinyl benzylate) in the neonatal urinary tract. The data demonstrate the existence of functional autonomic receptors in neonatal urinary tract smooth muscle.

Adrenergic Agonists↗
PubMed1989

Ultracytochemistry of calmodulin binding sites in myocardial cells by staining of frozen thin sections with colloidal gold-labeled calmodulin.

Calmodulin (CaM) has been implicated as a multifunctional regulator of Ca2+ in the cytoplasm of cells. We have recently introduced biologically active colloidal gold-labeled CaM as a marker for identifying potential CaM binding sites (unoccupied by endogenous CaM at the time of fixation) by electron microscopy and have stained frozen thin sections of rat cardiac muscle with this conjugate. In the presence of Ca2+, gold particles indicating CaM binding sites were found localized on the sarcoplasmic reticulum, mitochondria, and gap junctions. Control tissue sections treated with EGTA or exposed to excess amounts of unlabeled native CaM before staining showed no binding. We believe that cytochemistry of potential CaM binding sites revealed by staining with labeled exogenous CaM is useful in correlating known biochemical reactions of CaM with particular cell activities.

Animals↗
PubMed1989

Resistance to 1,25-dihydroxyvitamin D3 of cultured psoriatic epidermal keratinocytes isolated from involved and uninvolved skin.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3], a hormonally active form of vitamin D3, has been reported to stimulate epidermal differentiation and to be an effective treatment of psoriatic lesions. We studied the responsiveness of psoriatic epidermal keratinocytes to 1,25-(OH)2D3 in explant-outgrowth cultures of involved and uninvolved skin from six patients with psoriasis. A feeder layer was required for outgrowth of psoriatic epidermal keratinocytes of involved skin, but not for that of cells of uninvolved skin. The growth of normal epidermal keratinocytes was inhibited by 1,25-(OH)2D3, and the number of DNA-synthesizing cells, determined in autoradiographs, was reduced to about 15% of that in control cultures by 1 nmol/L 1,25-(OH)2D3 (0.4 ng/mL). Epidermal keratinocytes isolated from both involved and uninvolved skin of patients with psoriasis were resistant, and 100-fold more 1,25-(OH)2D3 was required to inhibit their DNA synthesis. These results afford new insight into the etiology and therapy of psoriasis.

Adult↗
PubMed1989

On the distribution of elastic fibers in the filiform papillae of Suncus murinus.

The distribution of elastic fibers in the filiform papillae of 1, 2, 3, 4 and 5 week-old and 6 month-old Suncus (Suncus murinus; insectivora) was examined by both Weigert's resorcin-fuchsin method and ultrastructural means. In the adult Suncus (6 months old), elastic fibers in the connective tissue core of the papillae were aligned perpendicularly to the epithelial surface and formed a palisade-like structure which encircled the margin of each connective tissue core. This characteristic structure was restricted to the filiform papillae in the anterior half of the lingual dorsum. In the filiform papillae of the posterior half, elastic fibers were markedly reduced and the palisade-like structure was not present. This characteristic pattern of elastic fiber distribution was established by 3 weeks of age. These observations reveal a characteristic structure consisting of elastic fibers in the connective tissue core of the filiform papillae and the regional distribution of this structure in the tongue. This suggests that the function of the structure in the connective tissue core is to protect against mechanical stress in mastication. The regional distribution of this structure may reflect the difference of mechanical strength between the anterior and posterior of the tongue caused by tongue movement during mastication.

Animals↗
PubMed1989

[Chemical properties of lipopolysaccharide (LPS) isolated from Vibrio anguillarum PT514].

Vibrio anguillarum, one of the causative agents of fish vibriosis, is serologically and biochemically divided into three groups (A, B and C). The chemical composition and molecular architecture of lipopolysaccharide (LPS) isolated from V. anguillarum PT 514, which belongs to serogroup B, were investigated. The LPS contained glucose (Glc), fructose (Fru), L-glycero-D-mannoheptose (L-D Hep), glucosamine (GlcN) and 4-amino-4,6-dideoxyglucose as sugar constituents in molar ratios of 8.9:0.7:3.0:1.1:1.6. Sephadex G-50 gel-chromatography of a degraded polysaccharide fraction separated from the LPS by 5% acetic acid hydrolysis suggested that the O-specific polysaccharide region consists of, in average, as much as 29 moles of Glc per 3 moles of L-D Hep, while the core polysaccharide contains at least Glc, L-D Hep and GlcN in molar ratios of 3.2 : 3.0 : 0.2. Fru and 4-amino-4,6-dideoxyglucose components were released from LPS on weak-acid hydrolysis, indicating that PT 514 LPS is distinguishable from those of Vibrio anguillarum belonging to the other serogroups. 2-Keto-3-deoxyoctonate (KDO), a common sugar constituent of gram-negative bacterial LPS, was not detected by Weissbach's color reaction under the conventional hydrolysis condition, but O-phosphoryl KDO was found in the strong-acid hydrolysate (4 M HCl, 100 C, 45 min). This substance was identical, at least in high-voltage paper electrophoresis, to 5-O-phosphoryl KDO.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrates↗
PubMed1989

[Dosimetry of fast neutrons in 1W nuclear reactor with plastic nuclear-track detectors].

A nuclear reactor at Kinki University is operated at the maximum of 1W. It produces fission neutrons as much as gamma-rays. To facilitate its use for neutron radiobiology, fast neutrons inside the reactor were measured with nuclear-track detectors TS 16 N and a pair of ion chambers. The angular dependence of TS 16 N response, an anisotropy of fast neutron fluxes in the reactor and misuse of the kerma factor assumed for radiation protection business are the major causes of discrepancy is measured doses by the two methods. Correction factors for the three causes are proposed. After correction, neutron doses estimated with TS 16 N and chambers agree within 5%. The dose-rate at the reactor's center is about 20 tissue-cGy/h. This is the first in situ dosimetry of fast neutrons in a reactor with track detectors attached to biologic samples. Our routine usage has demonstrated that, if used with caution, TS 16 N elements are handy, reliable monitors for fast neutron dosimetry as they are insensitive to contaminated gamma-rays and small enough to be attached to biologic samples.

Fast Neutrons↗
PubMed1989

N-salicylidene derivatives of pirarubicin.

The preparation and biological evaluation of N-salicylidene derivatives of pirarubicin are described. Pirarubicin was treated with various kinds of aryl aldehydes. Most of compounds synthesized here were more active than pirarubicin in vitro. Some of them showed significant prolongation of the survival period in experimental mice by oral administration. Interestingly, a derivative containing forphenicine exhibited the broadest dose-response range by intraperitoneal administration.

Animals↗
PubMed1989

Biosynthesis of benanomicins.

The biosynthesis of benanomicins A and B, produced by actinomycete strain MH193-16F4, was investigated by feeding experiments with 14C- and 13C-labeled compounds followed by measurement of radioactivity and 13C NMR analysis. A 2D double quantum coherence NMR spectrum of benanomicin A derived from sodium [1,2-13C2]acetate provided the location of intact acetate units, and confirmed the 13C assignments of benanomicins. The results indicate that the aglycone of benanomicins is derived from a dodecaketide, methionine and alanine.

Actinomycetales↗
PubMed1989

Antitumor activity of pyrindamycins A and B.

Pyrindamycins A(1) and B(2) exhibited stronger cytotoxic activities than doxorubicin towards murine and human tumor cell lines and especially towards doxorubicin-resistant cells. Pyrindamycins A and B were also active in vivo against P388/ADR, a multidrug-resistant tumor cell line. Intracellular accumulation of pyrindamycins A and B in P388/ADR was the same as in P388. These antibiotics strongly inhibited DNA synthesis compared with RNA or protein synthesis. They showed significant therapeutic effects towards murine leukemia, but not to solid tumors.

Animals↗
PubMed1989

Orally absorbable D-forphenicinol-cephalosporins.

The synthesis and biological evaluation of D-forphenicinol-cephalosporins are described. 7-Amino-3-(substituted)-3-cephem-4-carboxylic acid esters were coupled with N-tert-butoxy-carbonyl-D-forphenicinol derivatives. Most of cephalosporin analogs in this series had good antibacterial activities and were well absorbed from the gastrointestinal tract in mice. Among them, 7-(mono-O-methyl-D-forphenicinol)-3-propenyl analog showed the most significant result in biological evaluations.

Administration, Oral↗
PubMed1989

[AE characteristics during compression test of high-copper amalgams and visible light-cured composite resins].

Differences in environmental strength of high-copper amalgams and photo-cured composite resins for posterior after storage in deionized water at 37 degrees C for 1 year were evaluated by examining compressive strength and acoustic emission (AE) characteristics. The results were as follows: Microfailure in amalgams and composite resins was detected from the onset of stress and their microfailures toward catastrophic failure occurred at 70 to 90% of their ultimate strength. One-year compressive strength for amalgam decreased to 80 to 98% of its 24-hour compressive strength and that for composite resin to 65 to 75%.

Composite Resins↗