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Biomedical subjects

H Imanaka

Publications and source records attributed to H Imanaka.

At least 19 recordsLinked to original sources
PubMed1992

Biphenomycin A production by a mixed culture.

Production of biphenomycin A by Streptomyces griseorubiginosus 43708 was stimulated by a mixed culture with a partner strain, Pseudomonas maltophilia 1928. This stimulatory effect on biphenomycin A accumulation by the mixed culture was caused by the enzyme activity which strain 1928 possessed. It is suggested that in a mixed culture strain 43708 produces a precursor of biphenomycin A in culture broth and that strain 1928 converts the precursor to biphenomycin A.

Anti-Bacterial Agents↗
PubMed1992

Hypoplastic left heart syndrome associated with congenital right-sided diaphragmatic hernia and omphalocele.

Congenital diaphragmatic hernia (CDH) is associated with a variety of cardiac anomalies. However, its association with hypoplastic left heart syndrome (HLHS) is rare. We treated a female newborn with CDH, HLHS, and omphalocele. The operation for omphalocele and the diaphragmatic defect was successful, although the patient died of cardiac failure after Norwood's operation for HLHS. To our knowledge, this is the first reported case with a combination of these three major anomalies: CDH, HLHS, and omphalocele.

Female↗
PubMed1992

Capnometry during high-frequency oscillatory ventilation.

We used capnometry during high-frequency oscillatory ventilation (HFOV), and compared CO2 measurements at the distal and proximal ends of an endotracheal tube with arterial CO2 values. Ten white rabbits (mean weight, 2.00 +/- 0.2 [SD] kg) underwent tracheostomy under anesthesia with pentobarbital. The trachea was intubated with an endotracheal tube with a second lumen for sampling respiratory gas at the distal tip. Capnometry was performed through the lumen (CO2d) and the proximal end of the endotracheal tube (CO2p). The internal carotid artery was cannulated to sample blood for measuring arterial blood gases. The differences between CO2d, CO2p, and PaCO2 were measured. Only the relation between CO2d and PaCO2 was good (r = 0.915). We concluded that capnometry can be used during HFOV to estimate PaCO2 provided that respiratory gas is sampled from the distal tip of the endotracheal tube.

Animals↗
PubMed1992

WS9326A, a novel tachykinin antagonist isolated from Streptomyces violaceusniger no. 9326. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

Data from several studies suggest that tachykinins may play an important role in the pathophysiology of airway diseases, especially asthma. Our aim is to discover tachykinin antagonists which exhibit therapeutically useful anti-asthmatic activity. In our search for activities inhibiting the binding of [3H]substance P to guinea-pig lung membrane preparations, we have found that the fermentation product, WS9326A, isolated from Streptomyces violaceusniger, is a potent tachykinin receptor antagonist.

Animals↗
PubMed1992

WS9326A, a novel tachykinin antagonist isolated from Streptomyces violaceusniger no. 9326. II. Biological and pharmacological properties of WS9326A and tetrahydro-WS9326A (FK224)

WS9326A binds competitively to [3H]substance P (NK-1 receptor) binding sites on guinea-pig lung membranes (IC50 = 3.6 x 10(-6) M), and acts as a tachykinin antagonist in various functional assays. WS9326A inhibited tracheal constrictions produced by exogenously added substance P and neurokinin A, with IC50 values of 9.7 x 10(-6) M and 3.5 x 10(-6) M, respectively. WS9326A inhibited neurokinin A-induced bronchoconstriction in a dose dependent manner when administered to guinea-pigs intravenously together with neurokinin A, and was also effective in preventing capsaicin-induced bronchoconstriction, which is known to be caused by release of endogenous tachykinins (substance P and neurokinin A). FK224 (tetrahydro-WS9326A; catalytic hydrogenation of WS9326A gave FK224) was more potent than WS9326A in the [3H]substance P receptor binding assay using guinea-pig lung membrane (IC50 = 1.0 x 10(-7) M).

Animals↗
PubMed1992

A new angiogenesis inhibitor, FR-111142.

FR-111142 is a new angiogenesis inhibitor produced by a fungus Scolecobasidium arenarium F-2015. FR-111142 inhibited endothelial cell proliferation in vitro and angiogenesis in the growing chick chorioallantoic membrane model in vivo. Further, FR-111142 also suppressed the solid tumor growth in mice.

Allantois↗
PubMed1991

Construction of a 7-aminocephalosporanic acid (7ACA) biosynthetic operon and direct production of 7ACA in Acremonium chrysogenum.

We have used cDNA encoding D-amino acid oxidase, and genomic DNA encoding cephalosporin acylase from Fusarium solani and Pseudomonas diminuta, respectively, to construct a novel hybrid 7-aminocephalosporanic acid (7ACA) biosynthetic operon under the control of regulatory elements from the alkaline protease gene of Acremonium chrysogenum. Transformants of A. chrysogenum BC2116, a high cephalosporin-producing strain, containing this operon, synthesized and secreted low levels of 7ACA. Although the amounts are not yet commercially significant, this represents the first microbial production of 7ACA and demonstrates the feasibility of introducing new biosynthetic capabilities into industrial microorganisms by combining fungal and bacterial genes.

Acremonium↗
PubMed1991

Cloning and nucleotide sequencing of a novel 7 beta-(4-carboxybutanamido)cephalosporanic acid acylase gene of Bacillus laterosporus and its expression in Escherichia coli and Bacillus subtilis.

A strain of Bacillus species which produced an enzyme named glutaryl 7-ACA acylase which converts 7 beta-(4-carboxybutanamido)cephalosporanic acid (glutaryl 7-ACA) to 7-amino cephalosporanic acid (7-ACA) was isolated from soil. The gene for the glutaryl 7-ACA acylase was cloned with pHSG298 in Escherichia coli JM109, and the nucleotide sequence was determined by the M13 dideoxy chain termination method. The DNA sequence revealed only one large open reading frame composed of 1,902 bp corresponding to 634 amino acid residues. The deduced amino acid sequence contained a potential signal sequence in its amino-terminal region. Expression of the gene for glutaryl 7-ACA acylase was performed in both E. coli and Bacillus subtilis. The enzyme preparations purified from either recombinant strain of E. coli or B. subtilis were shown to be identical with each other as regards the profile of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and were composed of a single peptide with the molecular size of 70 kDa. Determination of the amino-terminal sequence of the two enzyme preparations revealed that both amino-terminal sequences (the first nine amino acids) were identical and completely coincided with residues 28 to 36 of the open reading frame. Extracellular excretion of the enzyme was observed in a recombinant strain of B. subtilis.

Amidohydrolases↗
PubMed1991

Cloning and nucleotide sequences of the complementary and genomic DNAs for the alkaline protease from Acremonium chrysogenum.

Complementary DNA encoding Ac. chrysogenum alkaline protease (Alp) was isolated from the Ac. chrysogenum ATCC11550 cDNA library by express-blot assay. The genomic DNAs encoding Ac. chrysogenum Alp were isolated from the Ac. chrysogenum genomic DNA library using the cloned cDNA as a probe. The 3150 nucleotides of the gene were sequenced. The prepro-Alp consists of 402 amino acids and two intervening sequences are found within the coding region. The amino acid sequence of Ac. chrysogenum Alp has 57% homology to that of Aspergillus oryzae Alp. The entire cDNA, encoding Ac. chrysogenum Alp, when introducing into the yeast Saccharomyces cerevisiae, directed the secretion of enzymatically active Alp into the culture medium.

Acremonium↗
PubMed1990

Measurement of functional residual capacity during high-frequency oscillatory ventilation (HFOV) by argon washout method without interruption of HFOV.

A modified indicator gas washout method was developed to measure functional residual capacity (FRC) during high-frequency oscillatory ventilation (HFOV) without interruption of HFOV. A hot-wire flowmeter and medical gas analyzer measured the flow rate and argon concentration, respectively, at the expiratory end of the respiratory circuit. Upstream of the hot-wire flowmeter, two heat-and-moisture exchangers for resistance and a rubber balloon for capacitance were placed to convert the oscillating expiratory flow to an almost continuous flow. This made it possible to measure FRC during HFOV without interrupting HFOV. To measure the volume of the entire respiratory circuit, a 10 percent argon in 90 percent oxygen gas mixture was initially used as a bias flow, and after equilibration, the test gas was switched to 100 percent oxygen. By electrical integration of the product of the expiratory flow rate and argon concentration, the total amount of argon equilibrated in the entire respiratory circuit was calculated. The volume of the circuit was calculated by dividing the total amount of argon by the initial argon concentration. Functional residual capacity plus the volume of the respiratory circuit was similarly calculated and the difference was estimated as FRC. The accuracy and reproducibility of our method were evaluated by using a one-compartment lung model. There was a high correlation between the volume setting of the model lung and the estimated FRC. This method can be used to estimate FRC in a one-compartment lung model during HFOV, and it is potentially useful in clinical situations.

Argon↗
PubMed1990

Studies on new dehydropeptidase inhibitors. III. Biological properties of WS1358A1.

WS1358A1, a novel inhibitor of renal dehydropeptidase (DHP), augmented the urinary recovery of a carbapenem antibiotic imipenem and improved its protective effect in experimental infections when simultaneously administered to mice with the antibiotic. WS1358A1 was a competitive DHP inhibitor with a Ki value of 1.6 x 10(-7) M.

Animals↗
PubMed1990

FR112123, a new oligopeptide antibiotic from Streptomyces viridochromogenes. Taxonomy, fermentation, isolation, physico-chemical properties, structure and biological activity.

FR112123 is a new oligopeptide antibiotic produced by Streptomyces viridochromogenes No. 7587. The structure of FR112123 is elucidated as N-(N6-(N2-glycyl-L-glutaminyl)-D-lysyl)-D-alanine (1) by spectroscopic and chemical evidence. It resembles a partial structure of peptidoglycan in bacteria. The compound has a superior activity against an Escherichia coli mutant sensitive to inhibitors of cell wall synthesis, although it has a weak activity against the parent strain. These suggest that FR112123 might act on the biosynthesis of bacterial cell wall.

Animals↗
PubMed1990

[Measurement of flow-resistive work of heat and moisture exchangers during simulated active breathing].

The performance of seven commercially available heat and moisture exchangers (HME) was evaluated in the dynamic flow state. A piston pump was used as a simulator with operative conditions with stroke volume of 500 ml and with respiratory rates of 20 and 40 cycles.min-1. A pressure-volume loop was produced for each HME and the flow-resistive work calculated. Each HME was studied under both dry and wet conditions. It was found that the flow-resistive work of the Humid-Vent 2 was the smallest and that of the Breathaid the largest under both conditions. The results suggest that application of HME causes a significant increase in resistance and demands a greater breathing effort from patients. Its use should thus be avoided in marginal patients.

Anesthesiology↗
PubMed1989

High-frequency oscillation for persistent fetal circulation after repair of congenital diaphragmatic hernia.

A female neonate who had been diagnosed as having congenital diaphragmatic hernia by ultrasonography was delivered by cesarean section. After the hernia was repaired, she developed hypoxemia and hypercapnia, probably due to persistent fetal circulation (PFC). Neither conventional mechanical ventilation (CMV) nor manual ventilation improved the respiratory status. High-frequency oscillation (HFO) successfully improved pulmonary gas exchange, but we failed to wean the patient from HFO by using intermittent HFO. The patient was again placed on CMV for weaning and was extubated on the 12th ICU day. We conclude that HFO can be an alternative respiratory modality in patients with respiratory failure due to PFC after the repair of congenital diaphragmatic hernia.

Female↗
PubMed1989

Effects of norepinephrine on renal function in septic patients with normal and elevated serum lactate levels.

Effects of iv norepinephrine (NE) on renal function were investigated retrospectively in 15 patients with hyperdynamic septic shock. All patients had either a low systolic BP less than 80 mm Hg, and/or oliguria less than 0.5 ml/kg-h. We examined their serum creatinine level (SCr), daily urine flow (UF), 24-h creatinine clearance (Ccr), and hemodynamic indices before and during NE infusion. Before NE administration, the patients were divided into those with with a serum lactate level (Lac) less than 20 mg/dl (group A, n = 9) and greater than 20 mg/dl (group B, n = 6). NE was infused continuously at rates between 0.05 and 0.24 microgram/kg.min which increased systolic BP by greater than or equal to 20 mm Hg. Cardiac index was not significantly changed in either group. In group A, NE increased both UF (p less than .05), and systemic vascular resistance index (SVRI) (p less than .01), but did not affect Ccr. In group B, NE did not increase UF nor SVRI, and decreased Ccr significantly (p less than .05). It is concluded that NE increased UF and SVRI only when Lac was in normal range; otherwise, NE reduced renal function. Thus, when administering NE to increase UF, both Lac and renal function should be monitored carefully.

Adult↗