Biomedical subjects

N Sakurai

Publications and source records attributed to N Sakurai.

At least 91 records · Page 5Linked to original sources

PubMed1995

Studies on the Chinese crude drug "shoma." IX. Three novel cyclolanostanol xylosides, cimicifugosides H-1, H-2 and H-5, from cimicifuga rhizome.

Three new cyclolanostanol xylosides were isolated from a batch of commercial Cimicifuga Rhizome, cimicifugoside H-1 (1), C35H52O9, mp 260-262 degrees C, [alpha]D -43.5 degrees, cimicifugoside H-2 (2), C35H54O10, mp 227-229 degrees C, [alpha]D -38.8 degrees, and cimicifugoside H-5 (3), C35H52O10, mp 262-264 degrees C, [alpha]D -22.9 degrees, together with known glycosides, actein and 27-deoxyactein. Their structures were determined on the basis of chemical and spectrometric evidence including an X-ray crystallographic analysis. The structure of cimicifugoside H-1 (1) was established as (20R,24R)-24,25-epoxy-11 beta-hydroxy-3-beta-(beta-D- xylopyranosyloxy)-9,19-cyclolanost-7-ene-16,23-dione. Cimicifugoside H-5 (3) is the 15-hydroxylated derivative of 1. Since 1 changed into cimicifugoside H-2 (2) on treatment with p-toluenesulfonic acid, 2 has a 24R,25-diol structure derived from 1 by opening its epoxy ring.

Analgesics, Non-Narcotic↗

PubMed1995

[Protective effects of the stem of Berchemia racemosa Sieb. et Zucc. on experimental liver injuries].

The methanol extract and water extract from the stem of Berchemia racemosa (Rhamnaceae) showed protective effects on liver injuries induced by carbon tetrachloride (CCl4) and alpha-naphthylisothiocyanate (ANIT) in rats. The acetone extract of B. racemosa protected the liver injury induced by CCl4. One of the protective substances was identified as carpusin. Some fractions showed significant protective effects against the liver injury and cholestasis induced by ANIT.

1-Naphthylisothiocyanate↗

PubMed1994

Improvement of a d-biotin-hyperproducing recombinant strain of Serratia marcescens.

We previously reported that a recombinant strain, SB412(pLGM304), was constructed from acidomycin-resistant mutants of Serratia marcescens and produced 200 mg of d-biotin per liter of a medium containing sucrose and urea (Sakurai et al., 1993a, b). In the present work, we intended to improve the d-biotin production. Both ethionine and S-2-aminoethylcysteine resistances were added to the host strain SB412, producing d-biotin at 20 mg l-1, and a resultant strain, ETA23, producing it at 33 mg l-1, was obtained. Cells of ETA23 did not maintain pLGM304 stably after greater than 30 generations under non-selective culture conditions. A new recombinant plasmid, pLGM304P, was constructed so as to be composed of pLGM304 and the parB locus, a plasmid-stabilizing element. ETA23 stably maintained pLGM304P after 50 generations under non-selective culture conditions. ETA23(pLGM304) produced 250 mg l-1 of d-biotin in a shaking flask under batch culture conditions and 500 mg l-1 in a jar fermentor under fed-batch culture conditions.

Biotin↗

PubMed1994

The rice culture filtrate of Bacillus cereus isolated from emetic-type food poisoning causes mitochondrial swelling in a HEp-2 cell.

Rice culture filtrates of Bacillus cereus SA-50, an emetic-type strain, produced a toxin which caused cytoplasmic vacuole formation in HEp-2 and HeLa cells. Electron microscopic observation revealed that the apparent vacuoles in HEp-2 seen under a light microscope were actually swollen mitochondria. The oxygen consumption of HEp-2 cells was accelerated by the addition of the rice culture filtrate as was measured with a polarographic oxymeter; a respiratory control ratio was 1.0 for control cells, while 1.4 for ones with the filtrates. The culture filtrates showed a similar effect on the isolated mouse liver mitochondria; respiratory control ratios for the mitochondria with and without the filtrates were 3.6 and 1.0, respectively. The affecting manner of the culture filtrates on the oxygen consumption of mitochondria was similar to that of 2,4-dinitrophenol, suggesting that the culture filtrate contains a toxin acting as an uncoupler of oxidative phosphorylation in mitochondria. It is likely that the culture filtrates containing the emetic toxin of B. cereus causes mitochondrial swelling with a close relationship to the uncoupling of the oxidative phosphorylation of mitochondria.

Animals↗

PubMed1994

T cell subsets in peripheral blood and cerebrospinal fluid from children with aseptic meningitis.

T cell subsets in peripheral blood (PB) and cerebrospinal fluid (CSF) obtained from patients with aseptic meningitis were studied using quantitative two-color fluorescence analysis with a flow cytometer. The percentage of HLA-DR+/CD3+ lymphocytes (activated T cells) in CSF was significantly increased in the recovery phase when compared to the acute phase, while no significant change in the activated T cells in PB was observed. More interestingly, CD4+ T lymphocytes in CSF were increased in the acute phase and subsequently decreased in the recovery phase. Instead, CD8+ T lymphocytes gradually accumulated into the CSF in the recovery phase, resulting in a successive decrease in the CD4/CD8 ratio. On the other hand, the CD4/CD8 ratio in PB remained normal during the course of aseptic meningitis. The present results suggest that T lymphocytes (CD4+ subset in the acute phase and CD8+ in the recovery phase) could be infiltrated and further activated at the site of inflammation, possibly in the subarachnoid space in the patients with aseptic meningitis.

Antibodies, Monoclonal↗

PubMed1994

Studies on the Chinese crude drug "Shoma." VIII. Two new triterpenol bisdesmosides, 3-arabinosyl-24-O-acetylhydroshengmanol 15-glucoside and 3-xylosyl-24-O-acetylhydroshengmanol 15-glucoside, from Cimicifuga dahurica.

Two new triterpenol glycosides were isolated from the rhizomes of Cimicifuga dahurica (Ranunculaceae): 3-arabinosyl-24-O-acetylhydroshengmanol 15-glucoside (1), C43H70O16, mp 222-223 degrees C, [alpha]D +21.0 degrees and 3-xylosyl-24-O-acetylhydroshengmanol 15-glucoside (2), C43H70O16, mp 208-210 degrees C, [alpha]D +9.5 degrees. On acidic hydrolysis, 1 afforded cimigenol (3) as an aglycone, and glucose and arabinose as sugars. On enzymatic hydrolysis with molsin, 1 afforded 24-O-acetylhydroshengmanol 15-O-glucoside (4). On the basis of chemical and spectral data, the structure of 1 was proposed to be (23R,24S)-24-acetoxy-3-O-alpha-L-arabinopyranosyloxy-16,23-e poxy-9,19- 15-O-beta-D-glucopyranoside. The other glycoside (2) showed, in its 13C-NMR spectrum, a pattern of chemical shifts very similar to that of 1. On acidic hydrolysis, 2 afforded cimigenol (3), xylose and glucose. On enzymatic hydrolysis with molsin, 2 afforded 4. From these results, the structure of 2 was proposed to be (23R,24S)-24-acetoxy-3-O-beta-D-xylopyranosyloxy-16,23-epoxy -9,19-cyclolanostane-15 alpha,16 xi,25-triol 15-O-beta-D-glucopyranoside.

Drugs, Chinese Herbal↗

PubMed1994

Increased risk factors for coronary artery disease in Japanese subjects with hyperinsulinemia or glucose intolerance.

OBJECTIVE: To understand the interrelationship of coronary artery disease (CAD) risk factors including hyperlipidemia, hypertension, and glucose intolerance to prevent and better manage this disease. RESEARCH DESIGN AND METHODS: We performed a 100-g oral glucose tolerance test in 2,113 subjects, and we evaluated their plasma lipid levels, blood pressure (BP), and plasma glucose and plasma insulin responses. RESULTS: Multiple regression analysis demonstrated a significant relationship of either BP, plasma triglyceride (TG), or high-density lipoprotein (HDL) cholesterol levels to plasma insulin and glucose response after the glucose load. Plasma cholesterol levels were related only to the plasma glucose response. In subjects matched for age, sex, and body mass index (BMI) with hyperinsulinemia or normoinsulinemia, the hyperinsulinemic subjects had a significantly higher mean BP and plasma TG level than the normoinsulinemic subjects (128.8/82.3 vs. 122.9/79.3 mmHg and 172.1 vs. 119.4 mg/dl), and the HDL-cholesterol level was significantly lower (43.9 vs. 47.8 mg/dl). Furthermore, subjects matched for age, sex, and BMI with glucose intolerance had a higher mean BP (128.4/81.8 vs. 123.5/78.7 mmHg) and higher plasma TG level (154.2 vs. 123.0 mg/dl) than those without glucose intolerance. CONCLUSIONS: Based on these findings, subjects with hyperinsulinemia or glucose intolerance should be carefully managed to prevent CAD, because they have more numerous and more severe risk factors than subjects with normal plasma insulin levels or subjects without glucose intolerance.

Blood Glucose↗

PubMed1994

[Movement-related cortical potential upon stepping forward].

We investigated movement-related cortical potentials (MRCPs) in 10 healthy subjects when they were stepping the right leg forward volitionally from the standing position, and compared with MRCPs associated with the foot dorsiflexion solely in sitting position. We recorded electroencephalogram (EEG), electrooculogram, surface electromyogram (EMG) on lower limb, and statokinesigram. We examined each EMG onset and several points on the statokinesigram as trigger points. MRCPs triggered by the right tibialis anterior, the left gastrocnemius, and the left soleus muscle had slow negative potentials containing slow phase and steeper phase. The potentials of both phases had the largest gradient at Cz. MRCPs triggered by the EMG onset of these three muscles resembled those associated with the foot dorsiflexion in their wave form, time course, and distribution pattern, but spread widely over the anterior recording sites. On the other hand, MRCPs triggered by the first deviation on the statokinesigram--by that first deviation assumed to take the first and foremost movement in this paradigm, were found to be delayed after the trigger point. The tibialis anterior muscle contributes to elevating a foot, and the contralateral gastrocnemius and soleus muscle to sustaining the weight. We were able to record apparent MRCPs when we adopted these EMG bursts, which play an important role in stepping forward, as trigger points. These records will be useful to analyze the mechanism of gait disturbance.

Action Potentials↗

PubMed1993

Treatment of postprandial hypotension with selective alpha 1 and beta 1 adrenergic agonists.

In order to treat postprandial hypotension (PPH), we orally administered a combination of denopamine (10 mg, a selective beta 1-adrenergic agonist) and midodrine-HCl (4 mg, a selective alpha 1-adrenergic agonist) to eight patients with autonomic failure (AF) prior to and after eating. When the patients were given 75 g glucose with 225 ml water without drugs, blood pressure fell subsequently, cardiac output (CO) was unchanged, and vascular resistance of the lower legs (LVR) decreased. However, concomitant administration of denopamine and midodrine-HCl prevented PPH and increased CO and LVR. The portal blood flow was not indifferent to the drugs. A marked increase in heart rate after drug administration was seen in some patients with AF, which reflects the supersensitivity to denopamine. Combined oral administration of denopamine and midodrine-HCl is a safe and useful therapy for PPH in patients with AF.

Adrenergic alpha-Agonists↗

PubMed1993

Postprandial hypotension: hemodynamic differences between multiple system atrophy and peripheral autonomic neuropathy.

To clarify the mechanism of postprandial hypotension (PPH), we performed hemodynamic investigation after oral glucose ingestion in ten patients with multiple system atrophy (MSA), three patients with peripheral autonomic neuropathy (PN) and 16 normal controls. Blood pressure (BP) and heart rate (HR) were measured with an automatic sphygmomanometer; cardiac out (CO) and lower leg blood flow (LBF) with impedance plethysmography; and portal blood flow (PBF) using a B-mode pulse Doppler. In normal subjects, BP, LBF and vascular resistance of the lower leg (LVR) were not changed, but HR slightly increased, and PBF and CO significantly increased after oral ingestion of 75 g glucose. In the patients with MSA, BP fell significantly 15 min after glucose ingestion, and HR and CO did not increase. PBF and LBF increased and LVR fell significantly. In PN patients, BP decreased at 15 min after glucose ingestion, but soon recovered. Increase of PBF and decrease of LVR in them were almost similar to those in the MSA group, and increase of CO was greater than that in the controls. These results suggest that both systemic vasodilatation (presumably due to gastrointestinal vasodilatatory peptides) and lack of compensatory increase of CO and LVR play important roles in PPH.

Administration, Oral↗

PubMed1993

[Polypeptide profiles of Chlamydia pneumoniae strains isolated from Japan and western blot analysis using patients' sera].

Polypeptide profiles were compared among Chlamydia pneumoniae strain of AC-43, which was isolated from a Japanese child, and other strains of C. pneumoniae. There was no distinctive differences among these strains. All strains showed marked band on 39.5 KDa area, which is equivalent with the major outer membrane protein (MOMP). Patients infected with C. pneumoniae were analyzed by Western blot using AC-43. Reaction for 98, 68, 60 KDa proteins were recognized among sera which showed positive results for anti-C. pneumoniae IgG antibody. There were two family members from whom C. pneumoniae was not isolated and anti-C. pneumoniae IgG antibody was negative. Sera obtained from them also showed weak reaction on 98 KDa protein area. Strong reaction on MOMP area was demonstrated in one patient from whom C. pneumoniae was isolated. Monoclonal antibody produced from AC-43 strain showed no reaction against homologous antigen. Reaction to 98 KDa protein was detected in all of the patients infected with C. pneumoniae. However, recognition to MOMP of C. pneumoniae seems to be different among patients. This result might suggest the presence of subtype among C. pneumoniae strains.

Blotting, Western↗

PubMed1993

[A report of 4 cases from whom Chlamydia pneumoniae was isolated].

Chlamydia pneumoniae (C. pneumoniae) was isolated from respiratory tract of 4 girls. Case 1 is 5-year-old, diagnosed as pneumonia, had had a prolonged productive cough. She was treated with RKM with improvement of symptoms, however, C. pneumoniae was isolated repeatedly and was not deleted. Neither anti-mycoplasmal nor viral antibodies were positive and no significant pathogens were cultured from nasophrayngeal swabs. Case 2, the sister of case 1, is a 3-year-old girl with acute bronchitis treated with EM. C. pneumoniae was negative on the tenth day after treatment. Case 3, a 5-year-old girl, had a fever and was diagnosed as bronchopneumonia with a mild attack of bronchial asthma. She was initially treated with CFIX followed by therapy including EM. Her symptoms had disappeared after treatment and anti-mycoplasmal antibody was 1:320. Case 4 was an asymptomatic carrier of C. pneumoniae. Specimen was obtained at regular health examinations of junior high school. C. pneumoniae was isolated from a 14-year-old girl without respiratory symptoms. Clinical figures of C. pneumoniae infections varies from asymptomatic carrier to pneumonia. Pathogens other than C. pneumoniae could modify symptoms of infections. Precise examinations of these cases would establish a proper management of a C. pneumoniae infection.

Adolescent↗

PubMed1993

Molecular breeding of a biotin-hyperproducing Serratia marcescens strain.

We previously reported that an acidomycin-resistant mutant of Serratia marcescens Sr41, SB304, and a mutant that was derived from SB304 and was resistant to a higher concentration of acidomycin, SB412, produced 5 and 20 mg of D-biotin, respectively, per liter of a medium containing sucrose and urea (N. Sakurai, Y. Imai, M. Masuda, S. Komatsubara, and T. Tosa, Appl. Environ. Microbiol. 59:2857-2863, 1993). In order to increase the productivity of D-biotin, the biotin (bio) operons were cloned from strains SB412, SB304, and 8000 (wild-type strain), and pLGM412, pLGM304, and pLGW101, respectively, were obtained through subcloning. These plasmids harbored 7.2-kb DNA fragments coding for the bioABFCD genes on a low-copy-number vector and were introduced into SB304, SB412, and 8000. Among the resulting recombinant strains, SB412(pLGM304) exhibited the highest D-biotin production (200 mg/liter) in the production medium. The plasmid was stably maintained in cells. Unexpectedly, SB412(pLGM412) grew very slowly, and the D-biotin productivity of this recombinant strain was not evaluated because pLGM412 was unstable.

Biotin↗

PubMed1993

Construction of a Biotin-Overproducing Strain of Serratia marcescens.

We have isolated mutants resistant to acidomycin, a biotin analog, from Serratia marcescens Sr41. Strain SB304, resistant to 0.5 mg of acidomycin (frequently called actithiazic acid) per ml, produced 5 mg of d-biotin per liter of a medium containing sucrose and urea. Strain SB412, which was isolated from SB304 on a minimal agar plate containing 2 mg of acidomycin per ml and 0.1 mg of 5-(2-thienyl)-valeric acid per ml, produced 20 mg of d-biotin per ml. The two enzymes related to biotin synthesis were found to be released from biotin-mediated feedback repression in these mutants. Transductional analysis revealed that SB412 had acquired at least two mutations, one in the biotin operon locus and the other in an unknown locus distant from the biotin operon locus.

Journal Article↗

PubMed1993

Sleep apnea and palatal myoclonus in a patient with neuro-Behçet syndrome.

A 50-year-old man with neuro-Behçet syndrome showed truncal imbalance, dementia, palatal myoclonus, snoring and rhythmic inspiration synchronized with palatal myoclonus. Magnetic resonance imaging showed hypertrophy of the bilateral inferior olivary nuclei with slight pontine atrophy. A polysomnographic recording disclosed sleep apnea during non-REM sleep: 6% central type, 46% mixed type, and 48% obstructive type. We speculate that lesions of the respiratory center or related structures in the brainstem resulted in sleep apnea and that laryngeal myoclonus also affected the apnea.

Behcet Syndrome↗

PubMed1993

[Purification of bone morphogenetic protein and investigation of its effects on osteoblastic cell line UMR108].

It is well known that the bone matrix contains proteins which can induce ectopic endochondral bone formation in vivo. One class of these proteins is the bone morphogenetic protein (BMP). In order to investigate the physiological function of the BMP, its purification was attempted from an extract of demineralized bone matrix and its actions on the osteoblastic cell line were investigated. To isolate the BMP, a demineralized bone matrix was extracted with 4M guanidine-HCl. A water-insoluble fraction (G-WI) was separated from the demineralized bone extract by dialysis against distilled water and centrifugation. The BMP was purified from G-WI by gel filtration on Sephacryl S-200 HR, cation exchange with Mono-S, heparin affinity column and finally by C1/8 reverse phase chromatography. Peptide sequence analysis revealed that the purified BMP fraction contained "BMP-3" reported by Wozney et al. (1988). In order to investigate its function, the BMP was applied to the rat osteogenic sarcoma cell line UMR108. The BMP inhibited the growth of the UMR108 cells and enhanced the alkaline phosphatase activity in a dose-responsive manner.

Amino Acid Sequence↗

PubMed1992

Berchemolide, a novel dimeric vanillic acid glucoside from Berchemia racemosa.

A new phenol glycoside named berchemolide was isolated together with (+)-catechin and (-)-epicatechin (as acetates), from the stems of Berchemia racemosa Sieb. et Zucc. (Rhamnaceae). The structure of berchemolide, having a dimeric dilactone structure with a 22-membered ring, was determined on the basis of spectral and chemical investigations. The conformation of berchemolide was calculated by MNDO (modified neglect of diatomic overlap).

Glucosides↗

PubMed1992

[Protective effects of the bark of Myrica rubra Sieb. et Zucc. on experimental liver injuries].

The methanol extract from the bark of Myrica rubra SIEB. et ZUCC. showed protective effects on liver injuries induced by carbon tetrachloride (CCl4) and alpha-naphthylisothiocyanate (ANIT) in rats. In this study, the fractions and some compounds from the bark of M. rubra were investigated for the protection against CCl4 inducing liver injuries in rats. The active principles for the protection were recognized in two fractions (M-3 and M-5 Fr. 1) obtained from the methanol extract, and one of the active principles in the fraction (M-3) was found to be myricanol 5-O-beta-D-(6'-O-galloyl)-glucopyranoside. In addition, these fractions protecting liver injuries induced by CCl4 showed significant protective effects against cholestasis induced by ANIT.

Animals↗