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Biomedical subjects

H Takai

Publications and source records attributed to H Takai.

At least 73 records · Page 4Linked to original sources
PubMed1992

Effect of cilostazol, a cyclic AMP phosphodiesterase inhibitor, on the proliferation of rat aortic smooth muscle cells in culture.

Cilostazol, a cyclic AMP phosphodiesterase inhibitor, has been used as an antiplatelet agent. In the present study, we investigated the in vitro effect of cilostazol on DNA synthesis in rat aortic arterial smooth muscle cells (SMCs) in culture stimulated with fetal calf serum (FCS), platelet-derived growth factor (PDGF), insulin, or insulin-like growth factor-I (IGF-I). Micromolar concentrations of cilostazol inhibited [3H]thymidine incorporation into DNA and cell growth as determined by cell number and protein concentration. Treatment with cilostazol increased the intracellular concentration of cyclic AMP, suggesting that the inhibition of SMC proliferation by cilostazol may be mediated through increased levels of cyclic AMP. The results suggested that cilostazol, by interfering with the proliferation of arterial SMCs, may have potential to prevent initiation and progression of atherosclerosis.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1992

Recurrent herpes zoster myelitis treated with human interferon alpha: a case report.

Recurrent herpes zoster myelitis is very rare. However, a case was recently observed in our hospital. A 43-year-old woman developed myelitis 2 weeks after development of shingles. Her condition was improved by methylprednisolone. Seven months later, she developed myelitis after development of shingles again. Antibody against varicella-zoster (VZV), increased in the serum, but was negative in the cerebrospinal fluid. Methylprednisolone was not sufficiently effective against this attack. The refractory sensory disturbance was improved by human interferon alpha (IFN-alpha). Natural killer cell activity, the helper T-cell/suppressor T-cell ratio and the kappa/lambda ratio of B-cells increased with clinical improvement. In this case, delayed-type hypersensitivity after VZV infection played a role in the occurrence of myelopathy and clinical improvement resulted from the immunosuppressive effects of IFN-alpha.

Adult↗
PubMed1992

Apolipoprotein(a) is present in urine and its excretion is decreased in patients with renal failure.

To investigate the relation between renal function and concentrations of lipoprotein(a) [Lp(a)] in serum, we measured Lp(a) in samples of serum and urine from patients with diabetes mellitus and in samples sent to a laboratory center for measurements of creatinine clearance. Serum Lp(a) concentrations were significantly increased in subjects with obvious renal dysfunction (serum creatinine > or = 176.8 mumol/L) compared with normal control subjects. Urinary Lp(a) excretion was decreased in subjects with obvious renal dysfunction compared with subjects without obvious renal dysfunction (serum creatinine < or = 88.4 mumol/L) and was negatively and positively correlated with serum creatinine and creatinine clearance, respectively. More than 80% of urinary Lp(a) was recovered in the d > 1.21 kg/L fraction. At least six bands for apolipoprotein(a) [apo(a)] fragments, which were smaller than native apo(a) in serum, were observed in urine by immunoblotting, and some of these were also detected in serum. Degraded apo(a) fragments are probably present in urine, and their excretion decreases in parallel with decreases in the glomerular filtration rate.

Adult↗
PubMed1992

Long-term results of surgical management of Achilles tendinitis in runners.

Achilles tendinitis is a common occurrence in long-distance runners. Although most respond well to conservative therapy, there are some who require operative intervention. The short-term results of surgical treatment are good, with a success rate more than 85%. The authors present nine successful long-term results in runners. However, in two of the runners who continued to compete and train at long distances, symptoms recurred. Reoperations were performed to permit successful running careers for five and nine years. Runners resumed their careers after the second operation by supervised training and long-distance, competitive activities.

Achilles Tendon↗
PubMed1991

Interleukin-6 levels in the cerebrospinal fluid of patients with multiple sclerosis.

We developed the competitive enzyme-linked immunosorbent assay for interleukin-6 (IL-6). The detection limit was 30 pg per ml. Using this method, we examined the IL-6 levels in the cerebrospinal fluid of 10 patients with multiple sclerosis (MS) and 12 age-matched normal controls. IL-6 was detected in 6 out of 10 patients with MS. There was no significant correlation between the IL-6 levels and other parameters, including IgG, IgG index, cell counts, total protein and albumin in the CSF. Our results suggest that IL-6 detected in the MS-CSF may have no correlation to the immunological processes.

Adult↗
PubMed1991

Plasma lipid and lipoprotein profile in elderly female runners.

Plasma lipid and lipoprotein profiles were compared in elderly female runners (RU: n = 15, aged 66 +/- 5 years, body fat 20 +/- 4%, training distance 35 +/- 15 km week-1, VO2max 36 +/- 4 ml kg-1 min-1, mean +/- SD) and age-matched untrained women (UT: n = 28, 66 +/- 4 years, body fat 26 +/- 6%, VO2max 26 +/- 3 ml kg-1 min-1). There were insignificant differences in total cholesterol (RU: 5.04 +/- 0.60 vs. UT: 5.48 +/- 0.85 mmol l-1), HDL-cholesterol (RU: 1.97 +/- 0.41 vs. UT: 1.91 +/- 0.36 mmol l-1) and LDL-cholesterol (RU: 2.72 +/- 0.59 vs. UT: 3.03 +/- 0.80 mmol l-1) between the two groups. Plasma triglyceride concentration of the runners was significantly lower than that of the untrained women (RU: 0.80 +/- 0.27 vs UT: 1.14 +/- 0.36 mmol l-1, P less than 0.01). No difference was observed in the LDL-cholesterol/HDL-cholesterol ratio between the two groups (RU: 1.45 +/- 0.51 vs UT: 1.64 +/- 0.53 units). These results suggest that regularly performed running of 35 km week-1 in elderly women does not further elevate their HDL-cholesterol level which is already high compared to the levels found in elderly men. However, elderly female runners appear to be protected against age-related increases in the levels of triglyceride and LDL-cholesterol.

Aged↗
PubMed1991

Studies on cardiotonic agents. VI. Synthesis of novel 4,5-dihydro-3(2H)-pyridazinone derivatives carrying some benzoheterocycles at the 6-position.

Several benzothiazolyl, imidazobenzothiazolyl, benzothienyl, benzothienopyrimidinyl and quinazolinyl 4,5-dihydro-3(2H)-pyridazinones were synthesized and examined for cardiotonic activity in anesthetized dogs after i.v. administration. Among them, 4-methylamino-7-(2,3,4,5-tetrahydro-5-methyl-3-oxo-6- pyridazinyl)quinazoline (36) showed potent and long-lasting inotropic activity (relative potency = 2.11, milrinone = 1). The activity of 36 was more potent than indolidan (2) (relative potency = 1.53) which is one of the most potent inotropic agents to date.

Animals↗
PubMed1991

Studies on cardiotonic agents. V. Synthesis of 1-(6,7-dimethoxy-4-quinazolinyl)piperidine derivatives carrying various 5-membered heterocyclic rings at the 4-position.

A series of 1-(6,7-dimethoxy-4-quinazolinyl)piperidines carrying various 5-membered heterocycles at the 4-position was synthesized and examined for cardiotonic activity in anesthesized dogs. The (4-oxo-2-thioxo-3-imidazolindinyl)amino derivatives showed the most potent inotropic activity. Marked loss of activity was observed in the 2,4-dihydro-3-thioxo-3H-1,2,4-triazolyl, the 2,4-dihydro-3-oxo-3H-pyrazolyl and the (2,3-dihydro-2-thioxo-3H-1,3,4-thiadiazol-5-yl)amino derivatives. The synthesis and structure-activity relationships are discussed.

Animals↗
PubMed1991

Studies on cardiotonic agents. VII. Potent cardiotonic agent KF15232 with myofibrillar Ca2+ sensitizing effect.

A series of novel 4,5-dihydro-5-methyl-6-(2 or 4-substituted 7-quinazolinyl)-3(2H)-pyridazinones was synthesized and examined for cardiotonic activity in anesthetized dogs. The 4-substituted aminoquinazolines generally showed potent and long-lasting inotropic activity. Fall in the activity was observed on the introduction of substituent at the 2-position of the quinazoline ring. The 3-substituted 4 (3H)-quinazolinimines generally exhibited weak activity. Ca2+ sensitizing effect of the 4-substituted amino derivatives was also examined in chemically skinned fiber from papillary muscle of guinea pig. The alkylamino derivatives exhibited small sensitizing effect, while the benzylamino derivatives exhibited large effect. Among them, KF15232 (Ix) was found to have the most potent cardiotonic and Ca2+ sensitizing activities.

Animals↗
PubMed1990

13C-N.M.R. spectra of cyclomalto-oligosaccharides (cyclodextrins), their derivatives, and complexes with azo dyes.

The nature of the inclusion complexes of several cyclomalto-oligosaccharides (cyclodextrins, CDs) with azo dyes has been studied on the basis of 13C-n.m.r. chemical shifts, relaxation times, correlation times, and broadening and doubling of the n.m.r. signals. All CDs show the azo dye-induced shifts at the narrow-rim side of the CD, indicating that the azo dyes protrude from the cavity. CD-induced shifts of azo dyes depend on the hydrophobic nature of the cavity, van der Waals forces, as well as ring-current and deformation effects, and suggest inclusion essentially from the hydrophobic site. The broadening and the doubling of the 13C-n.m.r. signals, the altered relaxation and correlation times, as well as the temperature dependence for these phenomena, also provide particular information about the characteristic host-guest interactions.

Azo Compounds↗