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Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 397 records · Page 22Linked to original sources

[Thrombin Reference Standard (Control 961) of National Institute of Health Sciences].

The "Thrombin Reference Standard (Control 961)" of National Institute of Health Sciences was prepared. The precision of filling into ampoule was about 1% as C.V. The content of a-thrombin was about 87%. The thrombin potency of the standard material was assayed against the Thrombin Reference Standard (Control 8710) according to the method of JP XIII and the potency was 1033 +/- 59 unit/ampoule. From the results, the potency of the proposed material for Thrombin Reference Standard was defined as 1,030 units per ampoule.

Government Agencies↗

[Kallidinogenase Reference Standard (Control 971) of National Institute of Health Sciences].

The "Kallidinogenase Reference Standard (Control 971)" of National Institute of Health Sciences was prepared. The kallidinogenase potency of the standard material was assayed against the 2nd Kallidinogenase Reference Standard (Control 854) by the enzyme assay method using H-D-valyl-L-leucyl-L-arginine-p-nitro-anilide as the substrate. The potency of the Kallidinogenase Reference Standard material thus obtained was defined as 119 unit per ampoule.

Government Agencies↗

[Retinol Acetate Reference Standard (Control 971) and Retinol Palmitate Reference Standard (Control 971) of National Institute of Health Sciences].

The "Retinol Acetate Reference Standard (Control 971)" and "Retinol Palmitate Reference Standard (Control 971)" of National Institute of Health Sciences using the assay of vitamin A ester were prepared. The proposed materials were evaluated in collaboration with four laboratories. Analytical data obtained were as follows. 1) The purities of retinol acetate and retinol palmitate measured by HPLC were 99.9 +/- 0.06% and 94.5 +/- 0.06%, respectively. 2) ultraviolet spectrum of retinol acetate and retinol palmitate showed the lambda max at 326-327 nm. 3) The difference in relative extinction of retinol acetate and retinol palmitate at 300 nm, 310 nm, 320 nm, 330 nm, 340 nm and 350 nm are within the range provided in JPXIII. 4) The contents of retinol acetate and retinol palmitate were 52,000 IU/g and 52,200 IU/g, respectively. Based on the above results, these proposed materials were authorized to be the Reference Standards of the National Institute of Health Sciences.

Diterpenes↗

[Cholecalciferol Reference Standard (Control 971) of National Institute of Health Sciences].

The raw material for cholecalciferol was examined for preparation of the "Cholecalciferol Reference Standard (Control 971)". Analytical data obtained were as follows: melting point, 83.8 degrees C; UV and infrared spectra, the same as those for JP Cholecalciferol Reference Standard (Control 945), respectively; specific absorbance at 265 nm, E1 cm 1% = 485; optical rotation, [alpha]D20 = +107.4 degrees; thin-layer chromatography and high-performance liquid chromatography (HPLC), no impurity was detected; assay, 98.9% by HPLC. Based on the above results, the raw material was authorized as the Cholecalciferol Reference Standard (Control 971) of National Institute of Health Science.

Chemical Phenomena↗

[Tocopherol Acetate Reference Standard (Control 971) of National Institute of Health Sciences].

The raw material of tocopherol acetate was examined for the preparation of the "Tocopherol Acetate Reference Standard (Control 971)". Analytical data obtained were as follows: infrared spectrum, the same as that of the Tocopherol Acetate Reference Standard (Control 941); specific absorbance, E1 cm 1% (284 nm) = 43.0; thin-layer chromatography, no impurities were detected until 50.0 micrograms of the loaded raw material; high-performance liquid chromatography (HPLC), one impurity was detected and the amount was estimated to be about 0.68%; assay by HPLC, 100.2%. Based on the above results, the raw material was authorized as the Tocopherol Acetate Reference Standard (Control 971) of National Institute of Health Sciences.

Government Agencies↗

[Ergocalciferol Reference Standard (Control 971) of National Institute of Health Sciences].

The raw material for ergocalciferol was examined for preparation of the "Ergocalciferol Reference Standard (Control 971)". Analytical data obtained were as follows: melting point, 116.7 degrees C; UV and infrared spectra, the same as those for JP Cholecalciferol Reference Standard; specific absorbance, E1 cm 1% = 461(265 nm); optical rotation, [alpha]D20 = +102.5 degrees; thin-layer chromatography and high-performance liquid chromatography (HPLC), no impurity was detected; assay, 102.4% by HPLC. Based on the above results, the raw material was authorized as the Ergocalciferol Reference Standard (Control 971) of National Institute of Health Sciences.

Chemical Phenomena↗

[Thiamine Hydrochloride Solution Reference Standard (Control 971) of National Institute of Health Sciences].

The raw material of thiamine hydrochloride solution was examined for the preparation of the "Thiamine Hydrochloride Solution Reference Standard (Control 971)". Analytical data obtained were as follows: assay by HPLC, 100.8%; spectrophotometric assay, 99.8%. Based on the above results, the raw material was authorized to be the Thiamine Hydrochloride Solution Reference Standard of the National Institute of Health Sciences.

Government Agencies↗

[Prednisolone Reference Standard (Control 971) of National Institute of Health Sciences].

The raw material of prednisolone was examined for the preparation of the "Prednisolone Reference Standard (Control 971)". Analytical data obtained were as follows: melting point, 238.4 degrees C (decomposition); infrared spectrum, the same as that of the Prednisolone Reference Standard (Control 911); UV spectrum, lambda max = 243 nm; specific absorbance, E1 cm 1% (243 nm) = 414.8; loss on drying, 0.06%; thin-layer chromatography, one impurity was detected; high-performance liquid chromatography (HPLC), 4 to 5 impurities were detected and the total amount was estimated to be about 0.51%; assay by HPLC, 100.6%. Based on the above results, the raw material was authorized as the Prednisolone Reference Standard (Control 971) of National Institute of Health Sciences.

Government Agencies↗

[On the "system repeatability" specified in the operating conditions for HPLC assay in JP monographs].

The system repeatability tests in the operating conditions for the HPLC assay by absolute calibration method are specified in 9 monographs in JP13 (Part 1). The reasonableness of the specified system repeatability, expressed in relative standard deviation(%), is discussed in consideration with the specified content and also the probability of Type 1 error(alpha). For simplification, it was assumed that the variance due to the analytical system(sigma s2) is equal to that due to other error sources(sigma e2). Based on the above considerations, it was concluded that the present specification of system repeatability(sigma s) in JP monographs is not always reasonable and some of them should be reexamined following to the described considerations in the text.

Chromatography, High Pressure Liquid↗

A novel mutation of the down-regulated in adenoma gene in a Japanese case with congential chloride diarrhea. Mutations in brief no. 198. Online.

Congenital chloride diarrhea (CLD) is an autosomal recessive disease characterized by excretion of watery stool with a high chloride content. Pathogenesis of CLD is a deficient absorption of chloride in exchange for bicarbonate in the ileum and the colon. In 1996, it was reported that 36 patients with CLD had mutations in the down-regulated in adenoma (DRA) gene; 32 Finnish patients had a three base deletion (951delGGT), 2 Polish patients had a one base mutation (371AtoT) and 2 Polish patients had a one base deletion (344delT). In this study we analyzed the DRA gene in a Japanese boy patient with CLD and in members of his family. The patient was found to have a two base deletion (TT) at nucleotide 1526-1527 within codon 509 which results in a frameshift leading to a permature stopping at codon 517. The patient was homozygous for the deletion, his parents and brother were heterozygous, and his sister was normal. This is the first case of CLD identified to carry a mutation of the DRA gene in Asia.

Adenoma↗

[Human herpesvirus-6 and -7 infection and bone marrow transplantation (BMT)].

In our all patients, the antibodies to HHV-6 and -7 were positive before BMT. HHV -6 and -7 DNA were sometimes detected after BMT, and HHV-6 infection after BMT caused fever, interstitial peumonitis, diarrhea, and myelosuppression. However, HHV -7 didn't induce any clinical symptoms. For the diagnosis of the HHV-6 or -7 infection, we used the virus isolation, semiquantitative PCR, and 4-hold elevation of the antibodies to HHV-6 or -7. Ganciclovir, foscarnet, high dose gamma-globulin and high dose acyclovir were useful for the treatment of HHV-6 infection after BMT. HHV-6 is an important agent for the fever of unknown origin, interstitial peumonitis, diarrhea, and myelosuppression after BMT.

Acyclovir↗

[Effect of epidural pressure gradient on buprenorphine flux through the dural hole after combined spinal-epidural anesthesia--comparison between bolus injection and continuous infusion].

Combined spinal-epidural anesthesia is a useful technique. However, there has been no attempt to investigate the risk of epidural opioid, especially buprenorphine, flux through the dural hole. The purpose of this study was to compare the effect of epidural buprenorphine administered across the dura into subarachnoid space, between two different methods of administration; bolus injection (Group I) and continuous infusion (Group II). Sixty patients for transvaginal hysterectomy were divided into two groups. Group I received buprenorphine 0.1-0.2 mg with 0.25% bupivacaine, and Group II 0.4 mg with 0.25% bupivacaine 40 ml continuously (infusion rate was 1.7 ml.h-1). Pain relief was similar in both groups, but the total buprenorphine requirement was lower in Group I than in Group II. The incidence of nausea and vomiting was significantly higher in Group I than that in Group II, 73% and 16%, respectively. It indicates that the increase of nausea and vomiting is predominantly determined by a high rate of flux into subarachnoid space and only partly determined by blood concentrations. In contrast to continuous infusion, the drug movement through the dural hole may increase by bolus injection due to its higher pressure. We recommend careful injection of epidural buprenorphine such as by continuous infusion with low pressure after combined spinal-epidural anesthesia.

Adult↗

[HELLP syndrome in triplet pregnancy complicated by DIC and transient diabetes insipidus].

A 29-year-old woman with a triplet pregnancy received emergency caesarean section in the 33rd week of pregnancy. She lost 2 babies, one of whom was a fetal death and the other a neonatal death. Three weeks before delivery, she was admitted to hospital suffering from vomiting, diarrhea and polyuria. There were no laboratory abnormalities such as a slightly elevated levels of liver enzymes, nor any clinical symptoms of preeclampsia. At the end of the operation, disseminated intravascular coagulation (DIC) occurred and HELLP syndrome was diagnosed. However, the hemoglobin level was in the normal range at this point. On the 2nd postoperative day, hemolytic anemia developed in spite of the resolution of other problems. We suggested that the hemolysis, which may have been caused by a latent hemoconcentration and a membrane disorder of the red cells, was an osmotic hemolysis. This case was unique for the following reasons; 1) a lack of symptoms of hypertension, proteinuria and edema, 2) complications due to diabetes insipidus, 3) postpartum severe hemolysis following latent hemoconcentration, and 4) slow progress of the condition after onset. Early detection of HELLP syndrome is difficult. It should be considered in the management of patients with unrecognizable hemoconcentration and nonspecific complications.

Adult↗

Disposition of a new nonsteroidal anti-inflammatory agent, S-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid, in rats, dogs and monkeys.

The disposition of S-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid (CAS 155680-07-2, S-MTPPA, code: M-5011) was studied after oral administration to rats, dogs and monkeys using the 14C-labeled drug. After oral dosing, S-MTPPA was well absorbed from the gastrointestinal tract, to the extent of 97.7% in rats. The concentration of S-MTPPA in rat plasma reached a peak (Cmax: 13.07 micrograms/ml) at 15 min (tmax) after dosing and declined with a half-life (t1/2) of 2.5 h. The values of the parameters tmax, Cmax and t1/2 for dogs were 30 min, 26.2 micrograms/ml and 7.0 h, and those for monkeys were 15 min, 12.8 micrograms/ml and 3.0 h, respectively. The radioactivity was widely distributed in tissues and almost completely excreted in urine and feces within 48 h after oral administration to rats. The excretion of radioactivity in bile, urine and feces within 48 h after oral administration of 14C-S-MTPPA to bile duct-cannulated rats amounted to 75.0, 18.6 and 1.4% of the dose, respectively. The drug was metabolized mainly by oxidation of the thiophenyl moiety and by glucuronidation of the carboxyl group in rats and monkeys. The major urinary and fecal metabolite in dogs was identified as the taurine conjugate of MTPPA.

Animals↗

[Serum concentration of coenzyme Q in xeroderma pigmentosum].

Serum concentrations of CoQ were measured on 22 xeroderma pigmentosum (XP) patients. 10 severely handicapped patients and 32 healthy children and adults. CoQ levels in XP patients (0.5 +/- 0.16 microgram/ml) and handicapped patients (0.57 +/- 0.21 microgram/ml) were lower than those in healthy children and adults (0.73 +/- 0.2 microgram/ml). CoQ levels in XP patients tended to decrease with age and were extremely low in two bed-ridden patients (0.29 and 0.21 microgram/ml), suggesting that CoQ levels decreased with disease progression. We studied the clinical effects of CoQ therapy in 19 XP patients with low CoQ levels. Eight patients showed increased activity in daily life. It suggests that XP patients have the disturbance of energy metabolism due to mitochondrial dysfunction. We consider it is worthwhile to research the mitocondrial function and the trial of CoQ therapy on XP patients.

Adolescent↗