Search PubMed⌕ Search

Biomedical subjects

M Doi

Publications and source records attributed to M Doi.

At least 217 records · Page 12Linked to original sources
PubMed1993

Scale-up of purine nucleoside fermentation from a shaking flask to a stirred-tank fermentor.

Scaling-up purine nucleoside fermentation by a mutant strain of Bacillus subtilis from a shaking flask to a stirred-tank fermentor was attempted. The dimensions and the operating conditions of the stirred tank were determined in order to satisfy the optimum conditions of O2 transfer and power consumption per unit volume for the shaking flask. When the purine nucleoside fermentation was carried out in the stirred-tank fermentor under these conditions, in which the temperature simulated that in the shaking flask, the total amount of purine nucleosides produced was almost the same as that in the shaking flask, but the accumulation ratio of guanosine to total nucleosides was different from that in the flask. Since urea could not be utilized so efficiently in the stirred-tank fermentor, the NH4+ concentration and the pH of the culture broth were lower than those in the shaking-flask culture during fermentation. The activity of inosine monophosphate dehydrogenase and the accumulation ratio were significantly affected by the NH+4 concentration. When the pH of the stirred-tank culture was maintained at 6.9 by ammonia water to keep the NH+4 level higher, the ratio was improved to the same level as that observed in the shaking-flask culture. The fermentation heat calculated from the shaking-flask data and its pattern of change were similar to those in the stirred-tank fermentor.

Ammonia↗
PubMed1993

Some properties and occurrence of cytochrome c-552 in the aerobic photosynthetic bacterium Roseobacter denitrificans.

Characteristics and occurrence of cytochrome c-552 from an aerobic photosynthetic bacterium, Roseobacter denitrificans, were described. Relative molecular mass of the cytrochrome was 13.5 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and 15,000 by gel filtration. This cytochrome was a acidic protein having a pI of 5.6 and Em was +215 mV at pH 7.0. Absorption peaks were at 278, 408 and 524 nm in the oxidized form and 416, 523 and 552 nm in the reduced form. Amino acid composition and N-terminal amino acid sequence of cytochrome c-552 determined for 24 residues had low similarities to those of cytochrome c-551 of this bacterium, which is homologous to cytochrome c2, although the physico-chemical properties of these two cytochromes were similar to each other. Cytochrome c-552 was maximally synthesized in the light under aerobic conditions but not in the dark. The synthesis also occurred in the presence of alternative acceptors such as trimethylamine N-oxide (TMAO) and nitrate under anaerobic conditions. Our results suggest that cytochrome c-552 is involved in TMAO respiration and denitrification in R. denitrificans, although the effect of light remains to be solved.

Amino Acid Sequence↗
PubMed1993

Cloning of the chitin synthase 3 gene from Candida albicans and its expression during yeast-hyphal transition.

The chitin synthase 3 gene (CACHS3) has been cloned from Candida albicans. The yeast CAL1 gene encoding the chitin synthase 3 of Saccharomyces cerevisiae was used as a probe for the isolation of the gene from C. albicans. The CAL1 homolog was identified in Southern blots of C. albicans genomic DNA and cloned from a C. albicans genomic DNA library. The nucleotide sequences of two partial clones were determined and combined giving a total length of 4610 bp. A continuous open reading frame of 3525 bp encoding a predicted protein of 1175 amino acids and molecular mass of 131 850 daltons was identified. A comparison of the deduced amino acid sequences of CAL1 and the Candida chitin synthase 3 protein showed 59.3% identity. Southern blot analysis indicates that the CACHS3 gene is present in a single copy in the genome and maps to chromosome I. Northern blot analysis shows that expression of chitin synthase 3 gene is dramatically increased during the transition from the yeast to the hyphal form of C. albicans. This change in transcription level strongly suggests that CACHS3 may play a role in Candida morphogenesis.

Amino Acid Sequence↗
PubMed1993

Airway irritation produced by volatile anaesthetics during brief inhalation: comparison of halothane, enflurane, isoflurane and sevoflurane.

Eleven male volunteers were studied to compare the airway irritation produced by the four anaesthetic agents: halothane, enflurane, isoflurane and sevoflurane at two concentrations, equivalent to one and two MAC. Tidal volume, respiratory frequency and functional residual capacity changes induced by 15 sec inhalation of the anaesthetics were measured using respiratory inductive plethysmograph. Appearance of the cough reflex was also observed. The order of subjective airway irritation was evaluated by the volunteers. Inhalation of the anaesthetic agents induced a decrease in tidal volume, increase in respiratory frequency and decrease in functional residual capacity. Significant changes were considered to have occurred if tidal volume and respiratory frequency changed by more than 30% from the resting values for at least ten seconds, or if functional residual capacity changed by more than 30% of the value at resting tidal volume, for at least ten seconds. Each change was induced most frequently by isoflurane followed by enflurane, halothane and, least frequently, by sevoflurane. The orders of appearance of the cough reflex and of subjective airway irritation were similar. Sevoflurane did not elicit a cough reflex. It is concluded that sevoflurane was the least irritant anaesthetic and is considered to be the most suitable for inhalational induction of anaesthesia.

Administration, Inhalation↗
PubMed1993

Is personality involved in the expression of dysmenorrhea in patients with endometriosis?

OBJECTIVE: To investigate whether a relationship exists between personality and expression of pain in women with endometriosis. STUDY DESIGN: With use of the Rosenzweig picture frustration study, the personality of women with endometriosis was assessed. These results were then correlated with the manifestation of pain. RESULTS: Women without dysmenorrhea tended to be less assertive compared with women who complained of dysmenorrhea and women without endometriosis. Those women without dysmenorrhea showed a destructive attitude in face of a problem. CONCLUSIONS: Personality affected the expression of pain. Pain caused by endometriosis was influenced by each personality type.

Adult↗
PubMed1993

Cerebral cortical pathology of sporadic olivopontocerebellar atrophy.

We examined the cerebral cortices of six brains from patients with sporadic olivopontocerebellar atrophy (s-OPCA), five control brains including four from patients who had died without neurological disease, and one from a patient with Holmes-type cerebellar cortical atrophy. Distinct laminar astrocytosis of the motor cortices in the fifth layer were demonstrated in 4 of 6 s-OPCA cases and in none of the control cases by immunohistochemistry for glial fibrillary acidic protein. The astrocytosis localized in the primary motor cortex and its distribution pattern were clearly different from those of so-called glial cytoplasmic inclusion. This cortical astrocytosis appears to be characteristic of s-OPCA and may reflect the pathology of the primary motor cortex.

Aged↗
PubMed1993

Molecular conformation of patellamide A, a cytotoxic cyclic peptide from the ascidian Lissoclinum patella, by X-ray crystal analysis.

As part of a series of investigations into the conformational stability of a C2-symmetric or related cyclic peptide isolated from the ascidian Lissoclinum patella, the molecular conformation of patellamide A, the chemical structure of which deviates slightly for C2-symmetry, was determined by X-ray crystal analysis. Patellamide A took on a saddle-shaped rectangular form and wrapped around the water and methanol solvents. This conformation which is very similar to that of C2-symmetric ascidiacyclamide would be proposed as a possible candidate for biologically "active" conformation.

Animals↗
PubMed1993

Recognition of nucleic acid base by tryptophan-containing peptides: spectroscopic study on interaction of N-acetylTrp-(Gly)m-Asp-(Gly)n-TrpNHCH3 (m = 0-2, n = 0-2) with guanine base.

As part of the designs of tryptophan-containing peptides which possess specific binding ability for each nucleic acid base, a series of N-acetylTrp-(Gly)m-Asp-(Gly)n-TrpNHCH3 (m = 0-2, n = 0-2) were chemically synthesized, and their abilities to form complexes with a guanine base were examined by the fluorescence and 1H-NMR methods. Fluorescence titration suggested the most preferential stacking interaction of the Trp-Gly-Asp-Trp sequence with the base. Analysis of low-field shifts of guanine N2-amino protons showed the hydrogen bond pairing with the Asp carboxyl side chain and its favorable formation for the -Gly-Asp-Trp peptide sequence. On the other hand, the largest up-field shift of guanine H8 proton was observed for Trp-Gly-Asp-Trp peptide, although its shifting degree caused by the stacking interaction with the Trp indole ring was not so significant. Thus, both spectroscopic methods indicated the Trp-Gly-Asp-Trp sequence to be most suitable for the guanine base recognition, which is constituted with the intimate cooperation of the hydrogen bond formation between the Asp carboxyl and guanine NH2 groups and the stacking interaction of the base with two neighboring Trp indole rings. This sequence preference would also be possible in acidic circumstances where the guanine N7 atom is protonated. A tentative interaction model is proposed based on these spectroscopic results.

Amino Acid Sequence↗
PubMed1993

Dehatrine, an antimalarial bisbenzylisoquinoline alkaloid from the Indonesian medicinal plant Beilschmiedia madang, isolated as a mixture of two rotational isomers.

Through bioassay-guided separations of the chemical constituents of the Indonesian medicinal plant Beilschmiedia madang BL. a bisbenzylisoquinoline alkaloid was obtained as the major antimalarial principle. The physicochemical properties of the alkaloid were consistent with the proposed structure of dehatrine. However, the alkaloid isolated by us was shown to be a mixture of two rotational isomers. The X-ray crystallographic analysis of 1 has shown that two rotamers are incorporated in a single crystal in 1:1 ratio. The complex NMR spectrum of 1 has also been defined as a mixture of two rotamers by extensive use of 2D (COSY and COLOC) techniques. Dehatrine has been shown to significantly inhibit the growth of cultured Plasmodium falciparum K1 strain (cholorquine resistant) with similar activity to quinine.

Alkaloids↗
PubMed1993

[Aggressive diffuse lymphoma with malignant pleural effusion expressing c-erbB-2 (neu) oncogene products].

An 83-year-old male was admitted with a right pleural effusion and generalized lymphadenopathy. Serum LDH level was elevated to 801 IU/L, and the pathological diagnosis from inguinal lymph node needle biopsy was malignant lymphoma (ML) of diffuse, large cell, non-cleaved type, according to the working formulation. The surface phenotypes of the malignant cells from the pleural effusion were analyzed by a fluorescent-activated cell sorter with a panel of monoclonal antibodies (MAbs). The ML cells coexpressed antigens detected by MAbs CD10 (CALLA), CD19, CD20, CD22, CD24, CD38, Ia, c-neu and surface immunoglobulin G kappa. A high expression of NRAS p21 was also detected by cytoplasmic immunofluorescence technique. The patient died 19 days later despite a combination of chemotherapy and intensive supportive therapy. From these findings it seems that c-neu may be a prognostic indicator not only for breast cancers but also for lymphoproliferative disorders. Further accumulation of such cases is needed.

Aged↗
PubMed1993

[A comparison of lymphocyte stimulation test results and challenge test results in 19 cases of antituberculous drug-induced allergy].

We clinically investigated 19 cases of antituberculous drug-induced allergy. The results of the challenge tests were positive in 30 out of the 55 drugs tested. The results of the lymphocyte stimulation tests were positive in 19 out of the 55 drugs tested. In 84.2% of the cases with positive lymphocyte stimulation test findings, the challenge test was also positive. It can be concluded from these results that the lymphocyte stimulation test may be useful in the detection of the causes of drug induced allergies in patients undergoing drug therapy for tuberculosis.

Adult↗
PubMed1993

[Long-term results of transscleral retinal detachment surgery with special reference to visual function].

We studied visual acuity and visual field of 44 eyes in 42 patients who had undergone transscleral retinal detachment surgery, they were classified into a preoperative group, a postoperative group, and a group ten years after surgery. With regard to visual acuity, the postoperative group showed a significant increase compared with the preoperative group (p < 0.001), and there was no significance between the postoperative group and the group ten years after surgery. In order to quantify the visual field obtained by Goldmann perimeter, the areal size of V-4 isopter, the areal size of I-4 isopter and the volume of the visual field were adopted in the present study. Each of the three mean values was high in the following order: the group ten years after surgery, the postoperative group, and the preoperative group. The mean value of the group ten years after surgery was respectively equivalent to 80.6%, 65.5%, and 71.1% of that of normal control in the order: the areal size of V-4 isopter, the areal size of I-4 isopter, and the volume of the visual field. Our results support the conclusion that the visual acuity acquired postoperatively can be maintained for ten years after surgery. The visual field acquired postoperatively also seems to be retained ten years after surgery.

Adolescent↗
PubMed1993

Retinal detachment due to breaks in pars plicata of ciliary body after endogenous fungal endophthalmitis.

An eye with retinal detachment due to breaks in the nonpigmented epithelium in the pars plicata of the ciliary body was reported in a patient who had been infected by endogenous Candida endophthalmitis about 3 years previously. He had no history of ocular trauma or atopic dermatitis, and had undergone extracapsular cataract extraction because of secondary cataract following the endophthalmitis. Three months later, the breaks were detected in his right eye, distributed extensively between the 3:30 and 11:45 o'clock meridians in the pars plicata. The posterior edges of these breaks were pulled to the contracted posterior capsule by zonular fibers. Posterior capsulectomy, vitrectomy, encircling and scleral buckling were performed and resulted in the reattachment of the retina. It was suggested that the ciliary body which had been damaged by endophthalmitis played a role in the development of these breaks.

Candidiasis↗
PubMed1993

[Assessment of the background count to measure the left ventricular ejection fraction with a nuclear stethoscope].

The nuclear stethoscope is a newly developed device for monitoring left ventricular ejection fraction (EF) with a pair of cadmium telluride detector for both left ventricular count (first channel) and background count (second channel). Although it is useful for evaluating the cardiac function during exercise, the methodology of the calculation for distinguishing the net ventricular blood count from the background count has not been established yet. In order to establish a reasonable method to calculate EF, we measured EF using a nuclear stethoscope and conventional gated blood pool scintigraphy in 20 healthy volunteers. All subjects underwent two supine ergometer exercise tests consisting of the 3 stages for the nuclear stethoscope and blood pool scintigraphy. The EF was determined with the following three method for the nuclear stethoscope; 1) Cut-off level was fixed at 70% of first channel, 2) Cut-off level at 75%, 3) Cut-off level was determined by the background count obtained from second channel. There was a poor relationship between the EFs obtained from gated blood scintigraphy and the EFs from the nuclear stethoscope calculated by any of these method. Regarding the EF calculated using the background count, however, the delta values of EF between rest and any of the 3 stages during exercise correlated closely to those EF from blood scintigraphy. When we apply the EF-at-rest value obtained from blood pool scintigraphy to analysis with the nuclear stethoscope, the EFs of 3 stages indicated good correlation (Stage I r = 0.91, Stage II r = 0.82, Stage III r = 0.69).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Clinical studies on lung disease caused by atypical mycobacteria in our hospital--especially in relation to drug susceptibility].

From 1987 to 1991, 27 patients were diagnosed as atypical mycobacteriosis in our hospital. Some strains of M. avium complex were found to be M. avium and M. intracellulare by means of a DNA probe test. 1. Total cases consisted of 14 males (the average age was 66.7 years) and 13 females (65.7 years). 2. M. avium complex was observed in 24 patients (9 cases of M. avium and 5 cases of M. intracellulare): M. kansasii and M. chelonae were found in 2 patients and 1 patient, respectively. 3. The findings of sputum cultures became negative three months after the chemotherapy treatment in 3 out of 25 patients. Two male patients were operated on and cured. Three patients died, and all of them had respiratory infections. 4. To determine the susceptibility of mycobacteria strains isolated from patients to various antimicrobial agents, an investigation was carried out. There were 88 strains of M. tuberculosis, 52 strains of M. avium complex (23 strains of M. avium and 17 strains of M. intracellulare), 3 strains of M. kansasii, 2 strains of M. gordonae and 2 strains of M. chelonae. 5. Strains of M. tuberculosis, M. kansasii and M. gordonae were susceptible to various antituberculous agents and ciprofloxacin. Strains of M. chelonae were susceptible to ciprofloxacin, and one strain was susceptible to streptomycin and ethionamide. 6. The M. avium strains were more susceptible to cycloserine and ciprofloxacin than were the M. intracellulare strains. Conversely, the M. intracellulare strains were more susceptible to ethambutol than were the M. avium strains.

Aged↗
PubMed1992

Crystal structure of papain-succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide complex at 1.7-A resolution: noncovalent binding mode of a common sequence of endogenous thiol protease inhibitors.

Succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide corresponding to a common sequence of endogenous thiol protease inhibitors is a noncompetitive reversible inhibitor of papain. In order to elucidate the binding mode of the inhibitor at the atomic level, its complex with papain was crystallized at ca. pH 7.0 using the hanging drop method, and the crystal structure was analyzed at 1.7-A resolution. The crystal has space group P2(1)2(1)2(1), with a = 43.09, b = 102.32, c = 49.69 A, and Z = 4. A total of 47,215 observed reflections were collected on the imaging plates using the same single crystal, and 19,833 unique reflections with Fo > sigma (Fo) were used for structure determination and refinement. The papain structure was determined by use of the atomic coordinates of papain previously reported, and then refined by the X-PLOR program. The inhibitor molecule was located on a difference Fourier map and fitted into the electron density with the aid of computer graphics. The complex structure was finally refined to R = 19.6% including 118 solvent molecules. The X-ray analysis of the complex crystal shows that the inhibitor is located at the R-domain side, not in the center of the binding site created by the R- and L-domains of papain. Such a binding mode of the inhibitor explains well the biological behavior that the inhibitor exhibits against papain. Comparison with the structure of papain-stefin B complex indicates that the structure of the Gln-Val-Val-Ala-Gly sequence itself is not necessarily the essential requisite for inhibitory activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗