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Biomedical subjects

H Iinuma

Publications and source records attributed to H Iinuma.

At least 37 records · Page 2Linked to original sources
PubMed1999

Lactonamycin, a new antimicrobial antibiotic produced by Streptomyces rishiriensis MJ773-88K4. II. Structure determination.

The absolute structure of a new antibiotic lactonamycin is described. The NMR studies deduced one of four possible structures for the aglycon attached by a rhodinose through glycosidic bond. The stereochemistry of the sugar obtained by an acid hydrolysis was determined to be L-form by measuring optical rotation. The stereochemistry of the aglycon was determined by X-ray crystallographic analysis.

Anti-Bacterial Agents↗
PubMed1999

Decatromicins A and B, new antibiotics produced by Actinomadura sp. MK73-NF4. I. Taxonomy, isolation, physico-chemical properties and biological activities.

New antibiotics designated decatromicins A and B were isolated from the culture broth of Actinomadura sp. MK73-NF4. They were purified by butyl acetate extraction, silica gel column chromatography, silica gel TLC and Sephadex LH-20 column chromatography. Decatromicins A and B inhibited growth of Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA).

Actinomycetales↗
PubMed1999

Decatromicins A and B, new antibiotics produced by Actinomadura sp. MK73-NF4. II. Structure determination.

The structures of decatromicins A and B that strongly inhibit the growth of MRSA were elucidated by the analysis of various NMR experiments. The planar structure was determined by 1H, 13C, COSY, HMQC and HMBC NMR spectra. The relative configuration of aglycone was elucidated by NOESY experiments and the absolute structure was determined by application of the modified Mosher's method. The absolute structure of glycosyl moiety was determined by X-ray analysis of the O-(p-bromobenzoyl) derivative.

Actinomycetales↗
PubMed1999

[Changes in the fractal component of spectral analysis of heart rate variability and systolic blood pressure variability during the head-up tilt test].

Blood pressure and heart rate change are related to the level of physical activity, and are correlated with each other. Heart rate and blood pressure signals were investigated by coarse graining spectral analysis and changes in the harmonic and non-harmonic (fractal) power were examined during the head-up tilt test. Fourteen healthy subjects, 9 men and 5 women (mean age 30.4 +/- 1.0 years) completed the test protocol of 15 min supine rest followed by the head-up tilt (80 degrees) test. Heart rate was measured continuously with standard bipolar leads and electrocardiography. A finger cuff was placed on the left index finger for beat-by-beat recording of systolic blood pressure based on the continuous noninvasive method, and the impulse train was stored on a personal computer for spectral analysis. The harmonic component, the integrated powers in the low-frequency and high-frequency regions, and the fractal component were then calculated. The fractal component was plotted on a log power versus log frequency plane with spectral index beta estimated as the slope of the linear regression of this 1/f beta plot. RR-interval was significantly shorter during the head-up tilt position than in the supine rest position with a marked reduction in the high-frequency power. The ratio of fractal component for total power was increased and the slope beta of the 1/f beta relationship was significantly greater in the head-up tilt (1.61 +/- 0.05) than in the supine rest (0.92 +/- 0.07) position. Systolic blood pressure showed a significant increase during head-up tilt, and marked increases in high-frequency power and fractal power. However, both the ratio of fractal component for total power and the slope beta remained unchanged. Further studies are needed to clarify whether the slope beta is essentially stable or variable in some conditions.

Adult↗
PubMed1998

Synthesis of anti-rheumatic agent epoxyquinomicin B.

Anti-rheumatic agent (+/-)-epoxyquinomicin B was synthesized for a 22% overall yield in eight steps from commercially available 3-hydroxy-4-nitrobenzaldehyde via the intermediate quinone 6 prepared by selective phenol oxidation of 5 by use of Fremy's salt as the key step.

Antirheumatic Agents↗
PubMed1998

Diperamycin, a new antimicrobial antibiotic produced by Streptomyces griseoaurantiacus MK393-AF2. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

Antibacterial antibiotics, diperamycin (1) was produced in the culture broth of Streptomyces griseoaurantiacus MK393-AF2. Various spectroscopic analyses of 1 suggested that 1 belonged to a member of cyclic hexadepsipeptide antibiotic. Antibiotic 1 had potent inhibitory activity against various Gram-positive bacteria including Enterococcus seriolicida and methicillin-resistant Staphylococcus aureus.

Animals↗
PubMed1998

Nothramicin, a new anthracycline antibiotic from Nocardia sp. MJ896-43F17.

A new antibiotic designated nothramicin was isolated from the culture broth of Nocardia sp. MJ896-43F17 which was closely related to Nocardia brasiliensis. It was isolated by the Diaion HP-20 column chromatography, butyl acetate extraction and purified by HPLC. It inhibited the growth of mycobacteria at the concentration of 1.56 approximately 25 microg/ml. Nothramicin was revealed to be a new member of anthracycline antibiotics by the various spectroscopies.

Animals↗
PubMed1998

Polyketomycin, a new antibiotic from Streptomyces sp. MK277-AF1. I. Taxonomy, production, isolation, physico-chemical properties and biological activities.

A new antibiotic designated polyketomycin was isolated from the culture broth of Streptomyces sp. MK277-AF1. It was purified by ethyl acetate extraction, Sephadex LH-20 column chromatography and centrifugal partition chromatography (CPC). It inhibited growth of Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). Its MICs were less than 0.2 microgram/ml. Polyketomycin exhibited cytotoxic activity against nine tumor cell lines at concentrations of 0.9-5.2 micrograms/ml.

Anti-Bacterial Agents↗
PubMed1997

Extensive RNA editing and possible double-stranded structures determining editing sites in the atpB transcripts of hornwort chloroplasts.

Three nonsense codons and an unusual initiation codon were located within the putative coding region of the atpB gene of chloroplast DNA of the hornwort Anthoceros formosae. Nucleotide sequencing of cDNA prepared from transcripts revealed extensive RNA editing. The unusual initiation codon ACG was changed to AUG and three nonsense codons were converted into sense codons. In total 15 C residues of the genomic DNA were replaced by U residues in the mRNA sequences, while 14 U residues were replaced by C residues. This is the highest number of editing events for a chloroplast mRNA reported so far. Partial editing was also shown in a cDNA clone where 23 sites were edited but six sites remained unedited, representing the existence of premature mRNA. The expected two-dimensional structure of the mRNA shows the existence of a sequence complementary to every editing site, which can produce continuous base pairing longer than 5 bp, suggesting that mispairing in the double strand is the site determinant for RNA editing in Anthoceros chloroplasts. Comparison of the cDNA sequence with other chloroplast genes suggests that the mechanism arose in the first land plants and has been reduced during evolution.

Amino Acid Sequence↗
PubMed1997

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. I. Taxonomy, fermentation, isolation and antimicrobial activities.

A new structural class of the antibiotic, epoxyquinomicins A, B, C and D were isolated from the culture broth of the strain MK299-95F4, which was related to Amycolatopsis sulphurea. Antimicrobial activity of epoxyquinomicins A and B were weak against Gram-positive bacteria, and epoxyquinomicins C and D showed almost no antimicrobial activity and no cytotoxicity. All these antibiotics showed improvement of collagen induced arthritis in vivo.

Actinobacteria↗
PubMed1997

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. II. Effect on type II collagen-induced arthritis in mice.

The anti-arthritic effects of epoxyquinomicins on type II collagen-induced arthritis in DBA/1J mice were examined. Prophylactic treatment with epoxyquinomicins A, B, C and D (1-4 mg/kg) had potent inhibitory effects on type II collagen-induced arthritis. In contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), epoxyquinomicin C (1-30 mg/kg) had neither an anti-inflammatory effect on carrageenan-induced paw edema in rats nor an analgesic effect on acetic acid-induced writhing in mice. These results suggest that the mode of action of epoxyquinomicins is different from that of NSAIDs and that epoxyquinomicins may become useful drugs for the treatment of rheumatoid arthritis.

Actinobacteria↗
PubMed1997

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. III. Physico-chemical properties and structure determination.

The structures of epoxyquinomicins A (1), B (2), C (3) and D (4) were determined by spectroscopic studies. Compound 1 was determined to be (5R,6S)-2-(3-chloro-2-hydroxybenzoylamino)-5-hydroxymethyl-5,6-epo xy- 2-cyclohexene-1,4-dione. Compound 2 was revealed to be the dechlorinated derivative of 1. Compounds 3 and 4 were determined to be the reduced derivative of 2 and 1, respectively.

Actinobacteria↗
PubMed1997

Recent therapeutic strategy for sustained ventricular tachycardia in Japan.

We investigated the therapeutic principles and strategies to treat sustained ventricular tachycardia (SVT) as five leading medical institutions in the Tokyo area and summarized the present situation of SVT treatment in Japan. Catheter ablation (ABL) has been almost established to be effective in idiopathic ventricular tachycardia (IVT) and was used as the last treatment in 60.3% of IVTs in this series. ABL may be the first option of therapy for IVT. In patients with SVT who have underlying cardiac diseases, the last treatment was class I drugs in 8.3%, class III drugs in 34.3%, combination drug therapy in 24.0%, ABL in 33.3%, surgical therapy (SUR) in 7.3%, and implantable cardioverter defibrillator (ICD) in 12.5% (nonpharmacological therapy in combination with other therapy). The use of class I drugs was not common, whereas class III drugs were used more frequently in patients with a low left ventricular ejection fraction. In some patients with reduced cardiac function, a combination of class III drugs and non-pharmacological therapy is appropriate.

Adult↗
PubMed1996

Extensive RNA editing of U to C in addition to C to U substitution in the rbcL transcripts of hornwort chloroplasts and the origin of RNA editing in green plants.

We cloned and sequenced a portion of chloroplast DNA from the hornwort Anthoceros formosae. A nucleotide sequence of 7556 bp contained structures similar to those of ndhK, ndhC, trnV, trnM, atpE, atpB, rbcL, trnR and accD. The arrangement of these was the same as that of other chloroplast DNA. However, two nonsense codons were located within the putative coding region of rbcL, although they were used as putative termination codons of the genes. RNA was extensively edited in the transcripts of rbcL when cDNA sequences were analyzed. The unusual nonsense codons of TGA and TAA became CGA and CAA respectively. These are examples of U to C type RNA editing, which was never been found before in chloroplast mRNA. In general, 13 Cs of genomic DNA were found as Ts in the cDNA sequence and seven Ts were found as Cs. This is the first finding of RNA editing on the transcripts of rbcL and also in bryophytes. This event had been thought to arise in land plants after the split of bryophytes. The origin of RNA editing is discussed in relation to the landing of green plants.

Amino Acid Sequence↗
PubMed1996

Comparison between Japan and North America in the post-hospital course after recovery from an acute coronary event.

We compared the post-hospital prognosis after an acute coronary event (acute myocardial infarction and unstable angina) in 106 patients in Japan vs. 789 patients in North America who were prospectively enrolled in the Multicenter Study of Myocardial Ischemia and were followed-up for an average of 26 months per patients. Risk factors more frequent in Japan were older age, males and smoking at enrollment, but the rest of many risk factors were similar. After adjusting for differences in clinical and medication variables, Cox analyses indicated patients in North America had a significantly greater risk of experiencing a primary end-point (cardiac death, non-fatal myocardial infarction or unstable angina) than patients in Japan (hazard ratio [North America:Japan] = 3.1, P = 0.003). There was a non-significant trend in the restricted end-points (cardiac death or non-fatal myocardial infarction) with North America having more frequent events than Japan (hazard ratio = 2.2, P = 0.12). The long-term outcome after recovery from an acute coronary event is more favorable in Japan than in North America, mostly due to a reduction in subsequent hospitalization for unstable angina. The reason for these findings cannot be explained by differences in the measured risk factors or medications.

Adult↗
PubMed1996

Isolation and synthesis of novel farnesyl protein transferase inhibitors, valinoctins A and B, from Streptomyces strain MJ858-NF3.

Two novel farnesyl protein transferase inhibitors, valinoctins A (1) and B (2), were isolated from the fermentation broth of Streptomyces strain MJ858-NF3. The tentative structures of these compounds were elucidated from NMR and mass spectra as dipeptides consisting of valine and a novel amino acyl moiety. Four possible isomers of valinoctin A were synthesized, and the protected derivative of the appropriate compound was crystallized to give the relative stereochemistry of X-ray analysis. Since the valine residue of valinoctin A was determined to be the L-configuration by a chiral HPLC column, absolute configuration of valinoctin A was determined.

Animals↗