Search PubMed⌕ Search

Biomedical subjects

N Takai

Publications and source records attributed to N Takai.

At least 109 records · Page 6Linked to original sources
PubMed1983

Secretion and re-absorption of glucose in rat submandibular and sublingual saliva.

Glucose permeation from blood to saliva appeared to follow the paracellular pathway in rat submandibular and sublingual glands, and the permeability was much higher in the sublingual than in the submandibular gland. The duct system re-absorbed glucose in the submandibular but not the sublingual gland. The glucose concentration in sublingual saliva was inversely related to the flow rate.

Animals↗
PubMed1983

Silicone as coating material for hemoperfusion.

The effectiveness of activated charcoal in direct hemoperfusion (DHP) has been recognized, but there are still problems with a decrease in solid components of blood and of dimishing adsorption capacity by coating layers on the surface of the sorbents in DHP. In the present study, we have developed activated charcoal derived from thermosetting resin, coated with silicone, and have observed changes in blood components after a 3 hr DHP. Adsorption capacity of the activated charcoal was determined in vitro, and was compared with noncoated charcoal and poly(hydroxyethyl methacrylate) (PHEMA) coated charcoal. Reduction in leukocyte and platelet counts was less with the silicone coated and PHEMA coated charcoals than with the noncoated charcoal. Variations in leukocyte counts and platelet counts were less in DHP with silicone-coated charcoal than with the others. Adsorption of the solid components of blood on the silicone-coated charcoal, examined by scanning electron microscopy after DHP, was very slight, showing its excellent applicability to DHP therapy. The degree of adsorption of various amino acids and related compounds on the silicone-coated charcoal was comparable to that on the noncoated charcoal. Thus, there seems only slight reduction in the degree of adsorption on the silicone-coated charcoal.

Adsorption↗
PubMed1982

Studies on the cyclic AMP response to thyroid stimulating immunoglobulin (TSI) and thyrotropin (TSH) in human thyroid cell monolayers.

Studies were conducted on the cultured human thyroid cell bioassay for thyroid stimulating immunoglobulin (TSI) and thyrotropin (TSH). In confirmation of the data of Kasagi, et al.,15 incubation of human thyroid cells in Hank's balanced salt solution deficient in NaCl increased the sensitivity of the c-AMP response to bovine TSH by approximately one order of magnitude. Half-maximal stimulation was attained at approximately 0.1 mU bTSH/ml. The effect of NaCl in the medium was greater with stimulation by TSI greater than hTSH greater than bTSH. In contract to incubations in NaCl(+)medium, with NaCl(-) medium most (70%-80%) of the c-AMP produced was released into the medium; this proportion remaining relatively constant over a wide range of bTSH and hTSH concentrations. At TSI concentrations higher than 3mg/ml efflux of c-AMP into the medium was significantly diminished. Stimulation by cholera toxin and prostaglandin E of thyroid cell c-AMP generation was not enhanced in NaCl(-) medium, in contrast to stimulation by TSH and TSI. The presence of 10(-4)m cycloheximide in NaCl(+) medium enhanced the c-AMP response to physiological concentrations of TSH. As with NaCl(-) medium, cycloheximide increased the sensitivity but not the maximum response of the c-AMP response to TSH. However no additivity was observed with NaCl(-) medium and cycloheximide. Human thyroid cells obtained from patients with Graves' disease are relatively insensitive to TSI stimulation. In NaCl(-) medium, however, the sensitivity of these cells to TSI stimulation is sufficient to enable them to be utilized in the TSI assay. The present state of the TSI assay is discussed.

Alprostadil↗
PubMed1981

Thyroid-stimulating immunoglobulin bioassay using cultured human thyroid cells.

Modifications are described in the cultured thyroid cell cAMP assay for TSH which make it suitable for the measurement of thyroid-stimulating immunoglobulins. Comparison was made between this assay and two others measuring cAMP responsiveness in human thyroid tissue, namely the thyroid slice and thyroid plasma membrane adenylate cyclase assays, all performed with the same tissue sample. Of immunoglobulin G (IgG) samples from 7 unselected patients with untreated hyperthyroidism associated with Graves' disease, 5 produced significant stimulation of cAMP content in cultured thyroid cells when compared to pooled normal IgG. None of these 7 produced a statistically significant increase in thyroid slice cAMP content when assayed in triplicate, the same replicate number used in the cultured thyroid cell assay. Similarly, none of the same Graves' IgG samples produced significant stimulation (vs. control IgG) in the membrane adenylate cyclase assay, in which sensitivity to TSH stimulation was very poor. With a scaled-down modification of the assay using microtiter wells and acetylation to enhance detection of cAMP in the RIA, significant TSI activity was observed in 15 of 18 (83%) IgG samples from patients with untreated Graves' disease. The data indicate the excellent sensitivity and precision of the thyroid cell cAMP assay, as well as its convenience.

Biological Assay↗
PubMed1980

High-performance anion-exchange chromatography of human urine using perchlorate gradient elution systems.

A 100-microliter volume of urine was chromatographed on a 50 X 0.4 cm I.D. column packed with a macroreticular anion-exchange resin. Elution was performed with a concave ammonium perchlorate gradient from 0 to 0.25 M at a flow-rate of 0.75 ml/min and a pressure of 7.5-11 MPa. With this perchlorate gradient, no baseline drift occurred in the detection at 254 nm, and even detection at 200 nm was possible. The effect of the addition of ethanol or acetonitrile to the ammonium perchlorate solution was investigated. For the assignment of peaks, ultraviolet spectra of the peaks were measured with stopped-flow scanning spectrophotometry.

Chromatography, Ion Exchange↗
PubMed1980

High-performance anion-exchange chromatography of ultraviolet-absorbing constitutents of human urine.

A 100-microliters urine sample was chromatographed on a column packed with a strongly basic macroreticular anion-exchange resin (Diaion CDR-10,5--7 micrometers with a nominal 35% cross linkage). The elution was performed with a linear acetate gradient from 0 to 6.0 M at an average flow-rate of 0.72 ml/min and at an average pressure of 104 kg/cm2. The relative standard deviation of retention times and peak height was +/- 4% or less. The properties of the macroreticular anion-exchange resin, the effect of the particle size, the pH of acetate buffers, and the effect of the flow-rate of the eluent on the separation were investigated. Thirty three components of urine were then resolved and named.

Anion Exchange Resins↗