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Biomedical subjects

M Ono

Publications and source records attributed to M Ono.

At least 91 records · Page 5Linked to original sources
PubMed2001

Determination of Wolbachia genome size by pulsed-field gel electrophoresis.

Genome sizes of six different Wolbachia strains from insect and nematode hosts have been determined by pulsed-field gel electrophoresis of purified DNA both before and after digestion with rare-cutting restriction endonucleases. Enzymes SmaI, ApaI, AscI, and FseI cleaved the studied Wolbachia strains at a small number of sites and were used for the determination of the genome sizes of wMelPop, wMel, and wMelCS (each 1.36 Mb), wRi (1.66 Mb), wBma (1.1 Mb), and wDim (0.95 Mb). The Wolbachia genomes studied were all much smaller than the genomes of free-living bacteria such as Escherichia coli (4.7 Mb), as is typical for obligate intracellular bacteria. There was considerable genome size variability among Wolbachia strains, especially between the more parasitic A group Wolbachia infections of insects and the mutualistic C and D group infections of nematodes. The studies described here found no evidence for extrachromosomal plasmid DNA in any of the strains examined. They also indicated that the Wolbachia genome is circular.

Chromosomes, Bacterial↗
PubMed2001

Quantitative comparison of anti-fading mounting media for confocal laser scanning microscopy.

Fading is one of the major obstacles to reliable observation in fluorescence microscopy. Using a confocal laser scanning microscope (CLSM) coupled to a computer, we quantitatively measured fading of fluorescence to formulate an equation, evaluated the anti-fading ability of several anti-fading media, and restored the faded images to the original level according to this equation. NIH 3T3 cells were stained with fluorescein isothiocyanate (FITC)-phalloidin, mounted with several commercial and homemade anti-fade media, and observed with CLSM under repeated illumination. With any mounting medium, attenuation of fluorescence intensity at a certain pixel occurred stepwise and the decrease was proportional to the intensity of the previous scan. From these results, we formulated an equation that has three coefficients: anti-fading factor (A), indicating the ability to retard fading; fluorescent intensity at the first scan (EM(1)); and background fluorescence (B). The fluorescent intensity at a certain point following nth scan is given as EM(n) = EM(1) * A ((n-1)). This equation was available for restoring faded images to their original states, even after the image had faded to only 60% of its original intensity.

3T3 Cells↗
PubMed2001

Anti-HIV-1 activity and structure-activity relationship of cepharanoline derivatives in chronically infected cells.

Cepharanthine (12-O-methyl cepharanoline) is a plant alkaloid and has been shown to inhibit tumour necrosis factor-alpha- or phorbol 12-myristate 13-acetate-induced HIV-1 replication in the chronically infected promonocytic cell line, U1. Its mechanism of action is considered to be the inhibition of nuclear factor kappaB, a potent inducer of HIV-1 gene expression. In this study, we have synthesized 96 derivatives of cepharanoline, including cepharanthine, and examined their inhibitory effects on HIV-1 replication in U1 cells. Among the 12-O-alkyl derivatives, cepharanthine proved to be the most active, and the activity decreased as the length of the alkyl chain increased. All of the 12-O-acyl derivatives were totally inactive, while a few 12-O-carbamoyl derivatives displayed modest activity. Since 12-O-ethyl derivatives were found to be as active as cepharanthine against HIV-1 replication, we further synthesized various 12-O-ethyl derivatives of cepharanoline. Among the derivatives, five proved to be more active inhibitors than cepharanthine, and the most active compound was 12-O-ethylpiperazinyl cepharanoline. The 50% effective concentrations of this compound and cepharanthine were 0.0041 and 0.028 microg/ml (0.0060 and 0.046 microM), respectively.

Alkaloids↗
PubMed2001

DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of flavonoids obtained from some medicinal plants.

A reactive oxygen species has been implicated in a range of human pathological diseases such as atherosclerosis and certain cancers. Flavonoids are reported to exhibit various biological activities, including antioxidative and free radical scavenging activities. Several flavonoids obtained from barley leaves, soybean and some medicinal plants, Silybum marianum, Sophorae Flos, Cinnamon, Ephedrae Herba and Scutellariae Radix, were tested for their DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. The structure-activity relationships suggested that not only the numbers of hydroxy group but also the position of hydroxy group might be important for mediating potent activity.

Bepridil↗
PubMed2001

Effects of dehydration temperatures on moisture absorption and dissolution behavior of theophylline.

Anhydrous theophylline was prepared by heating theophylline monohydrate at temperatures between 60 degrees C and 140 degrees C. The effects of dehydration temperatures on the moisture absorption and dissolution behavior of anhydrous theophylline were investigated in this study. The hydration rate of anhydrous theophylline at 95% relative humidity and 25 degrees C decreased with increasing dehydration temperatures. From the fitting analysis of solid-state reaction models, the hydration reaction was found to be governed by the phase boundary reaction model for samples prepared at lower dehydration temperatures (<100 degrees C) but the reaction obeyed the growth of nuclei reaction model when samples were dehydrated at higher temperatures. The dissolution rates of various anhydrous theophylline samples were measured by the rotating disk method. The calculated solubility of anhydrous theophylline prepared by heating was about 2.5 times higher than that of theophylline monohydrate. The phase transformation rate from the anhydrous form to the monohydrate during dissolution tests decreased with higher dehydration temperatures. It was found that the anhydrous theophylline prepared at different dehydration temperatures transformed to the monohydrate by way of different growth of hydrate nuclei mechanism.

Absorption↗
PubMed2001

Total synthesis of (S)-(+)-curcudiol, and (S)-(+)- and (R)-(-)-curcuphenol.

A highly enantioselective synthesis of the versatile chiral synthons possessing one stereogenic center, (S)- and (R)-4-aryl-5-hydroxy-(2E)-pentenoate (3) was achieved based on the enzymatic reaction of (+/-)-3 with commercially available lipases MY-30 or OF-360 from Candida rugosa. Application of (S)-3 and (R)-3 to the total syntheses of(S)-curcuphenol (1), (S)-curcudiol (2), and (R)-curcuphenol (1), respectively, is described.

Chromatography, High Pressure Liquid↗
PubMed2001

The reaction of (4R,5R)- and (4S,5S)-4,5-epoxy-2(E)-hexenoates and secondary amines.

A reaction of methyl (4R,5R)-4,5-epoxy-2(E)-hexenoate 1 with N-benzylmethylamine gave a diastereomerically pure methyl (4R,5R)-4,5-epoxy-(3S)-N-benzylmethylamino hexanoate 6 and methyl (4S,5R)-4-N-benzyl-methylamino-5-hydroxy-2(E)-hexenoate 7. The former was chemoenzymatically converted to (-)-osmundalactone 11, which is an aglycone of osmundalin. On the other hand, the directly conjugated addition of dimethylamine to methyl (4S,5S)-4,5-epoxy-2(E)-hexenoate 1 followed by treatment with MeOH at 40 degrees C exclusively provided methyl (4R,5S)-4-dimethylamino-5-hydroxy-2(E)-hexenoate 16, which was converted into L-(-)-forosamine 18.

Acetylation↗
PubMed2001

Doppler echocardiography-derived index of myocardial performance (TEI index): comparison with brain natriuretic peptide levels in various heart disease.

Plasma brain natriuretic peptide (BNP) has diagnostic and prognostic value in heart failure. Cardiac dysfunction varies from systolic or diastolic dysfunction alone to the combination of both. In the present study, Doppler echocardiographic parameters, including the Doppler echocardiography-derived index (TEI index), were compared with plasma BNP levels in 74 patients with various heart diseases. Blood sampling was performed before an echocardiographic examination was conducted. The TEI index was defined as the summation of isovolumic contraction and relaxation time divided by ejection time. In patients with left ventricular (LV) systolic dysfunction (ejection fraction <50%), the TEI index and BNP were increased significantly compared with patients with normal LV systolic function (p<0.05). Patients with a TEI index > or =0.45 showed significantly increased BNP levels compared with patients with a TEI index <0.45, irrespective of LV systolic function (241.4+/-451.2 vs 65.9+/-81.8pg/ml; p<0.05). The TEI index was significantly higher in patients with a BNP > or =73pg/ml than in patients with BNP <73pg/ml (0.57+/-0.24 vs 0.46+/-0.17; p<0.05). Other echocardiographic parameters did not correlate significantly with levels of plasma BNP. Of the echocardiographic parameters, a simple Doppler index (TEI index) that combines systolic and diastolic function can detect LV dysfunction in patients with high levels of plasma BNP in various heart diseases.

Adolescent↗
PubMed2001

Passive protection against porcine epidemic diarrhea (PED) virus in piglets by colostrum from immunized cows.

The effects of hyperimmune cow colostrum (HCC) on experimentally induced porcine epidemic diarrhea (PED) were investigated in piglets. In experiment 1, four 2-day-old piglets fed HCC containing an antibody titer of 1:512 and another four piglets fed unimmune cow colostrum (UCC) were orally inoculated with 10LD50 of PED virus. The piglets were given colostrum three times a day at 4 hr intervals. Half of the piglets fed HCC showed diarrhea and recovered, and all piglets survived. In contrast, all piglets fed UCC developed diarrhea and three of them died. In experiment 2, 2-day-old piglets fed HCC containing antibody titers of 1:512, 1:128 and 1:32, and UCC were inoculated with PED virus, and survival rates after challenge were 100, 75, 50 and 0 %, respectively. In experiment 3, 1-day-old piglets fed HCC with 1:512 antibody titer or UCC were inoculated and necropsied at 24, 48 and 72 hr after the inoculation for pathological examination. Piglets fed HCC remained healthy and PED virus antigen was not detected in the epithelial cells of the small intestine, and the length of the villi in small intestine was normal. On the other hand, in piglets fed UCC, villous atrophy and PED virus antigen were observed in epithelial cells of the jejunum and ileum from 24 hr. It was concluded that oral administration of HCC to piglets was effective in preventing PED virus infection and reduced their mortality.

Animals↗
PubMed2001

Immunohistopathologic demonstration of pleuropneumonia associated with Morganella morganii in a piglet.

Serofibrinous pleuropneumonia in a piglet was examined microbiologically and immunohistopathologically. Large numbers of Morganella morganii were isolated from the pneumonic lesion, but no other pathogens were identified. A large amount of M. morganii antigen was demonstrated, and its distribution was closely associated with the histologic lesion. This finding suggests that pleuropneumonia in piglets might be caused by M. morganii.

Animals↗
PubMed2001

Sequence analysis of candidate genes for common susceptibility to type 1 and type 2 diabetes in mice.

Although type 1 and type 2 diabetes are regarded as clinically distinct diseases, several lines of evidence have suggested common genetic factors between the two types of diabetes. The non-obese diabetic (NOD) mouse, an animal model of type 1 diabetes, and the Nagoya-Shibata-Yasuda (NSY) mouse, a model of type 2 diabetes, are derived from the same outbred colony, Jcl:HCR, suggesting a shared susceptibility between the two types of diabetes in mice. Genetic as well as functional studies have supported the possibility that Tcf2, which encodes the transcription factor, hepatocyte nuclear factor 1beta (HNF-1beta), is a candidate gene for the common susceptibility between NSY and NOD mice. Txn, encoding thioredoxin which is a redox (reduction/oxidation)-active protein, is also a positional and functional candidate for a common susceptibility gene. To investigate whether either of these two genes is a common susceptibility gene, the coding nucleotide sequences of these two genes were compared among the NSY, NOD and control C3H strains. The coding sequence of Tcf2 of the NOD mouse was identical to that of the C3H mouse, but was different from that of the NSY mouse. The coding sequence of Txn was identical in the three strains. These data suggest that neither of the two genes is a common susceptiblity gene between type 1 and type 2 diabetes in mice.

Animals↗
PubMed2001

Wolbachia infections of phlebotomine sand flies (Diptera: Psychodidae).

Old and New World phlebotomine sand fly species were screened for infection with Wolbachia, intracellular bacterial endosymbionts found in many arthropods and filarial nematodes. Of 53 samples representing 15 species, nine samples offour species were found positive for Wolbachia by polymerase chain reaction amplification using primers for the Wolbachia surface protein (wsp) gene. Five of the wsp gene fragments from four species were cloned, sequenced, and used for phylogenetic analysis. These wsp sequences were placed in three different clades within the arthropod associated Wolbachia (groups A and B), suggesting that Wolbacia has infected sand flies on more than one occasion. Two distantly related sand fly species, Lutzomyia (Psanthyromyia) shannoi (Dyar) and Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho), infected with an identical Wolbachia strain suggest a very recent horizontal transmission.

Animals↗
PubMed2001

Angiogenesis factors.

Angiogenesis is a recent highlight in the medical field; the developmental process and pathological conditions for various diseases can be understood from the novel aspect of "angiogenesis". Many angiogenesis-related factors are involved in the development of vessels during embryogenesis (vasculogenesis), as well as the induction of new vessels in response to physiological or pathological stimuli. In particular, the appearance of hemangioblasts, precursor cells for vascular endothelial cells and blood cells, and blood islands are expected to play a "prelude" role in tubulogenesis. Gene knock out mice of vascular endothelial growth factor (VEGF)/VEGF receptor, ephrin-B2, and angiopoietin-1 results in a failure of normal vessels production. Dormant factors derived from proteolytic cleavage of various physiological substrates are expected to balance a homeostasis of "angiogenic states" in the host. Furthermore, angiogenesis under various pathological conditions of malignant tumors, ocular diseases, psoriasis, rheumatoid arthritis, atherosclerosis and other diseases is associated with complex angiogenesis networks, suggesting pleiotropic mechanisms for angiogenesis.

Angiogenesis Inducing Agents↗
PubMed2001

Characteristics of cataracts in the Chinese Singaporean.

PURPOSE: To conduct an epidemiological survey of cataracts and examine the characteristics of lens opacities in Chinese Singaporeans. The results are then compared with those from two similar surveys previously done in Japan in Noto Area, Honshu, and Amami, Kyushu, respectively. SUBJECTS AND METHODS: 468 subjects of > or = 50 years of age, who responded to the invitation to participate, were examined. Examination principally included photo-documentation of the anterior and posterior segments of both eyes. Evaluation and grading of lens opacities were done using graphical analysis of Scheimpflug and retro-illumination images. Inter-group comparisons were based on statistical analysis of cataract prevalence and distribution. RESULTS: The prevalence of clear lenses decreased with aging with no significant difference between males and females--a finding common to Singapore and the two Japanese study groups. The prevalence of cataracts (or lens opacities of Grade II and above) in 60-79 year-old Singapore subjects was significantly higher than Noto and Amami subjects in the same age group. Further, cortical opacity was the main type in Singapore subjects in their 50s and which was significantly higher than Noto subjects of the same age group. In all age groups, the distribution and prevalence of both nuclear and subcapsular types in the Singapore group were higher than the two Japanese study groups. CONCLUSIONS: Cataracts in Chinese Singaporeans are characterized by a high prevalence of nuclear opacities which was generally seen in tropics and sub-tropics. Our study also suggested the involvement of solar-UV in cortical cataracts as well as that of additional risk factors, such as environmental temperature and race, in nuclear and subcapsular cataract formation.

Aged↗
PubMed2001

Accommodative microfluctuation in asthenopia caused by accommodative spasm.

BACKGROUND: Although many patients complain of eye fatigue caused by accommodative spasm, there have been no reports of a good objective examination method to diagnose it. PURPOSE: The spectral power of the high frequency component of the accommodative microfluctuation (spectral power of HFC) differs according to the constrictive degree of the accommodation. In this paper, we expatiated upon our previously reported analyzing processes of the spectral power of HFC, and we investigated the relationship between normal subjects and subjects with asthenopia. METHOD: The accommodative microfluctuation were recorded when the subjects were looking at a stable target. The waves of the accommodative microfluctuation were analyzed by FFT. RESULTS: The spectral power of HFC for the distant target was 50-60 in the subjects with normal vision, but it was higher in the subjects with asthenopia. CONCLUSION: Our results suggested that the ciliary muscle was also actively working in asthenopia caused by accommodative spasm even if the patient was looking at a distant target.

Accommodation, Ocular↗
PubMed2001

Effects of aflastatin A, an inhibitor of aflatoxin production, on aflatoxin biosynthetic pathway and glucose metabolism in Aspergillus parasiticus.

Aflastatin A inhibits aflatoxin production by Aspergillus parasiticus via an unknown mechanism. We found that aflastatin A clearly inhibited production of norsolorinic acid, an early biosynthetic intermediate of aflatoxin, at a concentration of 0.25 microg/ml. Reverse-transcriptase polymerase chain reaction (RT-PCR), and real-time quantitative PCR (TaqMan PCR) experiments indicated that the transcription of genes encoding aflatoxin biosynthetic enzymes (pksA, ver-1, and omtA) and a gene encoding a regulatory protein for expression of the biosynthetic enzymes (aflR) were significantly reduced by the addition of aflastatin A. We also found that aflastatin A elevated the glucose consumption and ethanol accumulation by A. parasiticus, and repressed transcription of genes involved in ethanol utilization. These results suggest that aflastatin A inhibits a very early step in aflatoxin biosynthesis prior to the transcription of aflR and can influence glucose metabolism in the fungus.

Aflatoxins↗