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Biomedical subjects

T Shintani

Publications and source records attributed to T Shintani.

At least 55 records · Page 3Linked to original sources
PubMed1996

6B4 proteoglycan/phosphacan, an extracellular variant of receptor-like protein-tyrosine phosphatase zeta/RPTPbeta, binds pleiotrophin/heparin-binding growth-associated molecule (HB-GAM).

A major chondroitin sulfate proteoglycan in the brain, 6B4 proteoglycan/phosphacan, corresponds to the extracellular region of a receptor-like protein-tyrosine phosphatase, PTPzeta/RPTPbeta. Here, we purified and characterized 6B4 proteoglycan-binding proteins from rat brain. From the CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid) extract of brain microsomal fractions, 18-, 28-, and 40-kDa proteins were specifically isolated using 6B4 proteoglycan-Sepharose. N-terminal amino acid sequencing identified the 18-kDa protein as pleiotrophin/heparin-binding growth-associated molecule (HB-GAM). Scatchard analysis of 6B4 proteoglycan-pleiotrophin binding revealed low (Kd = 3 nM) and high (Kd = 0.25 nM) affinity binding sites. Chondroitinase ABC digestion of the proteoglycan decreased the binding affinities to a single value (Kd = 13 nM) without changing the number of binding sites. This suggested the presence of two subpopulations of the proteoglycan with different chondroitin sulfate structures. Heparin potently inhibited binding of 6B4 proteoglycan to pleiotrophin (IC50 = 3.5 ng/ml). Heparan sulfate and chondroitin sulfate C inhibited moderately (IC50 = 150 and 400 ng/ml, respectively), but, in contrast, chondroitin sulfate A and keratan sulfate were poor inhibitors (IC50 > 100 microg/ml). Immunofluorescence and immunoblotting analyses indicated that both 6B4 proteoglycan and PTPzeta are located on cortical neurons. Anti-6B4 proteoglycan antibody added to the culture medium suppressed pleiotrophin-induced neurite outgrowth of cortical neurons. These results suggested that interaction between 6B4 proteoglycan and pleiotrophin is required for the action of pleiotrophin, and chondroitin sulfate chains on 6B4 proteoglycan play regulatory roles in its binding.

Amino Acid Sequence↗
PubMed1996

Characterization of the S1 subsite specificity of aspergillopepsin I by site-directed mutagenesis.

The structural determinants of S1 substrate specificity of aspergillopepsin I (API; EC 3.4.23.18), an aspartic proteinase from Aspergillus saitoi, were investigated by site-directed mutagenesis. Aspartic proteinases generally favor hydrophobic amino acids at P1 and P1'. However, API accommodates a Lys residue at P1, which leads to activation of trypsinogen. On the basis of amino acid sequence alignments of aspartic proteinases, Asp-76 and Ser-78 of API are conserved only in fungal enzymes with the ability to activate trypsinogen, and are located in the active-site flap. Site-directed mutants (D76N, D76E, D76S, D76T, S78A, and delta S78) were constructed, overexpressed in Escherichia coli cells and purified for comparative studies using natural and synthetic substrates. Substitution of Asp-76 to Ser or Thr and deletion of Ser-78, corresponding to the mammalian aspartic proteinases, caused drastic decreases in the activities towards substrates containing a basic amino acid residue at P1. In contrast, substrates with a hydrophobic residue at P1 were effectively hydrolyzed by each mutant enzyme. These results demonstrate that Asp-76 and Ser-78 residues on the active site flap play important roles in the recognition of a basic amino acid residue at the P1 position.

Amino Acid Sequence↗
PubMed1996

[Importance of oral and dental care in home medical care].

Recently, the importance of home medical care has been stressed. But patients, those assisting them and home care nurses do not attach much importance to oral and dental care in home medical care. When we visit patients who have asked for dental treatment through home care nurses, they appeared to have very poor oral hygiene; cavities were uncared for, dental plaque and dental calculus built up, and they used ill-fitting dentures. Through home dental care visits, it was not just the dental treatment but advice on dental hygiene management and diet that helped patients regain their appetite and bring back a smile to their face, while giving a rhythm to their life. This created a certain human feeling and brought about better patient quality of life (QOL), while at the same time helping to improve the QOL of the family as well.

Delivery of Health Care↗
PubMed1996

Adenotonsillar hypertrophy and skeletal morphology of children with obstructive sleep apnea syndrome.

To define the role of adenotonsillar hypertrophy and facial morphology in obstructive sleep apnea (OSA) in children we performed a cephalometric analysis of an OSA group and an age-matched control group. Adenotonsillar hypertrophy was remarkable in OSA children at every age level. Maxillary protrusion expressed by SNA was significantly smaller in the OSA group than in the control group for elderly children (5-9 years old). Mandibul protrusion expressed by SNB was significantly smaller in the OSA group even at younger ages (1-2 years). The hyoid bone was significantly lower in the OSA group than in the control group who were from 3 to 6 years. Environmental factors due to upper airway obstruction as well as genetic factors are suspected to cause abnormal facial morphology in OSA children.

Adenoids↗
PubMed1995

A highly sensitive and selective method for the determination of Leukotriene B4 in human plasma by negative ion chemical ionization/gas chromatography/tandem mass spectrometry.

We have developed a highly sensitive and highly selective method for the determination of Leukotriene B4 (LTB4) in human plasma using negative ion chemical ionization/gas chromatography/tandem mass spectrometry (NICI/GS/MS/MS) analysis. The developed method was summarized as follows. Deuterated LTB4 (d4-LTB4) was added to human plasma samples as an internal standard, and samples were extracted by a Sep-pak C18 column. Extracted LTB4 was derivatized into the pentafluorobenzyl ester of bis-trimethylsilyl ether (PFB-TMS-LTB4) and quantified on the basis of selected reaction monitoring (SRM) at m/z 299 of [M-PFB-2TMSOH]- by NICI/GC/MS/MS analysis, which was the product ion of [M-PFB]-. The detection limit for the quantification of LTB4 in human plasma was 10 pg ml-1, sufficiently sensitive to determine the concentrations of endogenous LTB4 in human plasma. The plasma level of LTB4 measured in healthy male volunteers was 33.85 +/- 33.91 pg ml-1 (mean +/- S.D. in six volunteers). The technique of MS/MS used in this method offers much greater sensitivity and selectivity than single-stage mass spectrometry. The developed method showed good reproducibility with a simple and rapid extraction procedure, and would be useful for examining the relationship between various disease states and the levels of LTB4 in biological fluids.

Fluorobenzenes↗
PubMed1995

Recognition system for dietary fatty acids in the rat small intestine.

Linoleic acid and oleic acid markedly increased the influx of 45Ca into isolated intestinal epithelial cells, and this increase reflected a rise in the intracellular calcium level. Methyl linoleate had no effect, while glutamic acid and somatostatin both inhibited the linoleic acid-induced influx of 45Ca. In addition, methyl linoleate had no effect, while glutamic acid inhibited linoleic acid-induced hormone-responsive pancreatic exocrine secretion.

Animals↗
PubMed1995

The recognition system of dietary fatty acids by the rat small intestinal cells.

Small intestinal epithelial cells interact with a rather high concentration of fatty acids derived from the diet. These fatty acids directly or indirectly regulate the functions of the small intestine. We report here that linoleic acid and oleic acid markedly increased the influx of 45Ca2+ into the small intestinal epithelial cell line (IEC 6). By contrast, octanoic acid, methyl linoleate, and linolyl alcohol had no effect on the influx. Acidic amino acids, methyl linoleate, and linolyl alcohol, inhibited the linoleic acid-induced influx of 45Ca2+, indicating that activation of the influx by linoleic acid depended on the chain length and was affected by the presence of a carboxyl group. Of the gastrointestinal hormones, somatostatin specifically inhibited the linoleic acid-induced influx of 45Ca2+.

Amino Acids↗
PubMed1995

[Vestibular function in cochlear implants--prognostic factors and postoperative damage].

Eighteen patients with a 22-channel cochlear implant were evaluated both pre- and postoperatively with vestibular function tests; caloric test and body balance test using stabilometry. Preoperative promontory stimulation results and postoperative psychophysical factors of the cochlear implant showed no correlation with the preoperative vestibular function test results. The results of speech perception tests were not affected by the degree of residual vestibular function in any of the patients. However, for patients with deafness for a period of 10 to 20 years, the degree of the residual vestibular function estimated by the caloric test showed a correlation with the results of speech perception tests, significantly in the consonant recognition score. The results, not of length or the Rombberg ratio, but rather of the area of body sway, showed a correlation with the results of speech perception tests; consonant recognition, in patients with a short duration of deafness. Therefore preoperative vestibular function results may be useful as a predictive factor in postoperative speech perception; consonant recognition, for patients with a short duration of deafness. Reduced results of caloric testing after surgery were found in one of 11 patients (9%) with residual vestibular function. The occurrence of vertigo immediately after surgery was observed in 5 of 18 patients (28%), but this symptom was transient. No change in stabilometry results, pre-versus post-operatively, was observed. Thus, vestibular damage after surgery was considered to be minimal.

Adult↗
PubMed1994

Multiple receptor-like protein tyrosine phosphatases in the form of chondroitin sulfate proteoglycan.

The possibility that some of the brain proteoglycans are receptor-like protein tyrosine phosphatases (PTPases) was investigated. Membrane-bound proteoglycan fractions were prepared from the postnuclear membrane fraction of 8-day-old rat brain by DEAE ion-exchange chromatography and CsCl density gradient centrifugation. The isolated proteoglycan fractions showed high PTPase specific activities together with the typical PTPase characteristics. Renaturation experiments indicated that chondroitin sulfate proteoglycans with 380- and 170-kDa core proteins carried the PTPase activity. The proteoglycan with 380-kDa core protein was identified as RPTP beta/zeta bearing HNK-1 carbohydrate.

Animals↗
PubMed1994

Primary structure of aspergillopepsin I deduced from nucleotide sequence of the gene and aspartic acid-76 is an essential active site of the enzyme for trypsinogen activation.

The coding region of the aspergillopepsin I (EC 3.4.23.18) gene occupies 1340 base pairs of the genomic DNA and is separated into four exons by three introns. The predicted amino-acid sequence of aspergillopepsin I consists of 325 residues and is 32% and 27% homologous with those of human pepsin and calf chymosin. The cDNA of the gene prepared from mRNA has been cloned and expressed in yeast cells. To identify the residue of the substrate binding pocket in determining the specificity of aspergillopepsin I towards basic substrates, this residue was replaced with a serine residue by site-directed mutagenesis. The mutation is a single amino-acid change, Asp-76 converted to Ser-D76S, in the enzyme. The striking feature of this is that only the trypsinogen activating activity was destroyed. We therefore concluded that Asp-76 is the binding site towards basic substrates.

Amino Acid Sequence↗
PubMed1994

Simultaneous determination of human neutrophil elastase inhibitor (ONO-5046) and its metabolite in plasma and urine by direct injection column-switching HPLC.

The direct injection method for the simultaneous determination of a human neutrophil elastase inhibitor (ONO-5046) and its metabolite (ONO-EI-601) in plasma and urine has been developed using a column-switching HPLC system. The system was set up with a pre-treatment column, a pre-concentration column and an analytical column which were connected in series via two automatic switching valves. The calibration lines showed a good linearity for concentrations of ONO-5046 and ONO-EI-601 in a range of 156-20000 ng ml-1 in plasma and 1.56-100 micrograms ml-1 in urine, all correlation coefficients being greater than 0.9999. The limit of quantitation of ONO-5046 was 156 ng ml-1 in plasma, that of ONO-EI-601 was 313 ng ml-1 in plasma, and those of ONO-5046 and ONO-EI-601 were 1.56 micrograms ml-1 in urine. The developed method is rapid and sensitive with automated operation, allowing untreated samples to be analysed every 45 min. The application of the present method to the real plasma and urine samples proved to be useful for pharmacokinetic, toxicological and clinical studies.

Chromatography, High Pressure Liquid↗
PubMed1994

Calcein release from temperature-sensitive liposome with or without stirring.

Characteristics of the calcein release from temperature-sensitive liposomes with or without stirring were studied. Calcein release from DPPC(dipalmitoylphosphatidylcholine) REV(reverse phase evaporation vesicle) with stirring occurred at a temperature lower by 8 degrees than that without stirring. DPPC-DSPC(distearoylphosphatidylcholine)-mixed REV showed the maximum release(%) for calcein, near 40 degrees C with stirring and 45 degrees C without stirring.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

[Efficacy of tonsillectomy for improving skin lesions of Pustulosis palmaris et plantaris--evaluation of 289 cases at the Department of Otolaryngology of Sapporo Medical University].

In recent years, Pustulosis palmaris et plantaris (PPP) has been described as one of the representative second lesions of focal tonsillitis in Japan. We selected 289 cases of PPP, treated with bilateral tonsillectomy at our department over the past 12 years for this clinical evaluation. In 211 of those 289 tonsillectomy cases, follow-up was done for more than 3 months after operation. Prior to tonsillectomy, 196 cases suffered from PPP only, 90 cases had the complication of osteo-arthral lesions such as sterno-costa-clavicular hyperosteosis (SCCH), rheumatoid arthritis, and soon, whereas only 3 cases showed simultaneous lesions of Psoriasis vulgaris. The efficacy of tonsillectomy for improving the skin lesions was classified into 6 grades, mainly based upon individual evaluation by each patient as follows; disappeared, remarkably improved, improved, slightly improved, unchanged, and worsened. According to our 211 cases, post tonsillectomy improvement of skin lesions was very obvious, with disappearance occurring in 54.3% of cases and remarkable improvement in 21.4%. Age of onset and the duration from onset to tonsillectomy showed no association with effectiveness. However, the shorter the duration from onset to tonsillectomy, the fewer days were required for improvement of the skin lesions. The rate of improvement of PPP rose in conjunction with the number of days after tonsillectomy. We conclude that it requires 12 months, at minimum, to determine the efficacy of tonsillectomy as a treatment for PPP.

Adolescent↗
PubMed1994

The Waianae Diet Program: a culturally sensitive, community-based obesity and clinical intervention program for the Native Hawaiian population.

The Waianae Diet Program (WDP) is a community-based program designed at the Waianae Coast Comprehensive Health Center in response to the high rates of obesity and chronic disease among Native Hawaiians. Its foundation is a 3-week program of traditional Hawaiian diet and cultural teachings. It employs 8 innovations in clinical nutrition and health promotion theory: 1. Non-calorie restricted weight loss protocol, 2. Dietary clinical intervention, 3. Cultural sensitivity, 4. Transition diet, 5. Whole-person approach, 6. Group ohana (family) support, 7. Community intervention, and 8. Role modeling. It has demonstrated significant weight loss with no calorie restriction, improvement in blood pressure, serum glucose, and serum lipids. It appears to have wide acceptance in the Hawaiian community. More studies are warranted to determine the long-term effect of this program.

Community Health Services↗