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Biomedical subjects

N Sakurai

Publications and source records attributed to N Sakurai.

At least 109 records · Page 6Linked to original sources
PubMed1992

Renal microangiography and correlated histopathological observation of cows with nephropathy.

Seven Holstein-Friesian cows showing chronic nephropathy were studied by renal microangiography and its correlated histopathology. In cases of pyelonephritis associated with severe pathological lesions such as thickening of arterial walls, narrowing of the arterial and arteriolar lumen, and interstitial inflammation and abscess formation, patchy loss of the peritubular capillary plexus from the cortex to the medulla was clearly demonstrated by microangiography. Interlobular arteries were tortuous and attenuated or truncated. Opacification in the vasa rectae and interstitial capillaries was increased. Extensive non-perfused regions could be detected in the cortex. In cases of mild interstitial nephritis and moderate pyelonephritis, microangiography showed focal changes in the renal vasculature. Microangiography is thus shown to clearly demonstrate changes in the renal vasculature corresponding to the severity of the histopathological lesions.

Angiography↗
PubMed1992

Identification of effective component from a traditional herbal medicine and the inhibitory effects on experimental glomerular lesion in mice.

Effective constituents for renal disease were partially purified from a herbal prescription. The efficacy on renal diseases was examined using an experimental model system of glomerular lesion in mice induced by Agkistrodon acutus venom (Ac1-P). The extract of boiling water of the herbal prescription (P-3) was first fractionated by ether into an acidic fraction and a mixture of basic and neutral fractions. The acidic fraction was proved to be more effective and then further examined by thin layer chromatography and spectrophotometry. One of the main components was confirmed to be caffeic acid which had inhibitory effect on renal failure in mice by Ac1-P. This effect was considered to be caused by caffeic acid inhibiting the proteolytic enzyme activity of Ac1-P. Caffeic acid should thus have prophylactic or inhibitory effect on glomerular disease in which proteolytic enzymes may have pathogenic roles.

Animals↗
PubMed1992

Dural arteriovenous malformation and sinus thromboses in a patient with prostate cancer: an autopsy case.

A 67-year old man with prostate cancer showed Balint's syndrome, memory disturbance, anosognosia and hallucinations after having been comatose. Radiological findings indicated bilateral dural arteriovenous malformation (DAVM) and thrombosis at the bilateral transverse sinuses and superior sagittal sinus. Pathological findings showed abnormally dilated veins, diffuse neuron loss and gliosis in the parieto-occipital lobe. The chlormadinone and prostate cancer are speculated to have caused the dural sinus thrombosis which probably induced the DAVM.

Adenocarcinoma↗
PubMed1992

[Movement-related cortical potential in patients with cerebellar dentate degeneration].

We reported movement-related cortical potentials (MRCPs) in 11 patients with lesion of the dentate nucleus (Machado-Joseph disease (MJD) 7 cases, dentato-rubro-pallido-luysian atrophy (DRPLA)1, myoclonus epilepsy associated with ragged-red fibers (MERRF)1, dyssynergia cerebellaris myoclonica (DCM) 2), and compared with those of 7 cases of multiple system atrophy (MSA) who were postulated to have mild dentate lesions (striato-nigral degeneration 2 cases, Shy-Drager syndrome 2, sporadic olivo-ponto-cerebellar atrophy 3), and 7 control subjects without any neurological findings. Further we classified the diseases into the following two groups based on the lesion of the dentate nucleus. One was MJD group that had normal or slightly abnormal electroencephalogram (EEG), and the other was DN group (DRPLA, MERRF, DCM) that had markedly abnormal EEG. One of the main findings from this study was smaller slope of the Ns' in the MJD and DN group and normal slope of BP. There was no significant difference in the slope of Ns' between MJD patients and DN patients. This result shows EEG abnormalities have no influence on MRCP recordings. These results suggest that Ns' component may reflect the function in the cerebellar dentate nucleus, and that MRCP is a useful diagnostic method in patients with cerebellar ataxia.

Adolescent↗
PubMed1991

Clinical observations on lower respiratory tract infections with special reference to serum IgE levels.

To examine if the occurrence of wheezing among children with lower respiratory tract infections is associated with atopic predisposition, serum levels of IgE were determined for groups of children with or without wheezing, during infection with Mycoplasma pneumoniae or respiratory syncytial virus (RSV). In M. pneumoniae infection, more than 60% of wheezy children over 2 years of age showed a high IgE level (200 IU/mL or more), while IgE levels were less than 200 IU/mL in 73% of non-wheezy children. In RSV infection, the incidence of high IgE levels among wheezy children was nearly double that of non-wheezy children, although the difference was not significant. These results suggest that in children an allergic disposition is involved in the occurrence of wheezing during the course of lower respiratory tract infections.

Age Factors↗
PubMed1991

Differential Effect of Auxin on Molecular Weight Distributions of Xyloglucans in Cell Walls of Outer and Inner Tissues from Segments of Dark Grown Squash (Cucurbita maxima Duch.) Hypocotyls.

Effects of indole-3-acetic acid (IAA) on the mechanical properties of cell walls and structures of cell wall polysaccharides in outer and inner tissues of segments of dark grown squash (Cucurbita maxima Duch.) hypocotyls were investigated. IAA induced the elongation of unpeeled, intact segments, but had no effect on the elongation of peeled segments. IAA induced the cell wall loosening in outer tissues as studied by the stress-relaxation analysis but not in inner tissues. IAA-induced changes in the net sugar content of cell wall fractions in outer and inner tissues were very small. Extracted hemicellulosic xyloglucans derived from outer tissues had a molecular weight about two times as large as in inner tissues, and the molecular weight of xyloglucans in both outer and inner tissues decreased during incubation. IAA substantially accelerated the depolymerization of xyloglucans in outer tissues, while it prevented that in inner tissues. These results suggest that IAA-induced growth in intact segments is due to the cell wall loosening in outer tissues, and that IAA-accelerated depolymerization of hemicellulosic xyloglucans in outer tissues is involved in the cell wall loosening processes.

Journal Article↗
PubMed1991

Novel Technique for Measuring Tissue Firmness within Tomato (Lycopersicon esculentum Mill.) Fruit.

Developmental changes of tomato (Lycopersicon esculentum) fruit tissues during maturation were analyzed by a physically defined method (stress-relaxation analysis). The tip of a conical probe connected to a load sensor was positioned on the cut surface of a sliced tomato fruit, and the decay of the imposed stress was monitored. Stress-relaxation data thus obtained were used for the calculation of three stress-relaxation parameters. Different zones within tomato fruit harvested at six different ripening stages were analyzed. One of the stress-relaxation parameters, minimum stress-relaxation time (T(0)), decreased as the fruits matured. The decrease in T(0) was first found in the core of the carpel junction within the endopericarp at the blossom end during the breaker stage. The decrease in T(0) progressed from the blossom end, through the equatorial region and finally throughout the shoulder, as the fruit matured. In mature green fruit, T(0) values within the placenta and the proximal carpel junction were lower than those by other parts of the fruit. For all measurements the maximum stress-relaxation time was not substantially changed during maturation, nor were their changes observed in different regions of the fruit. The observed relaxation rate was therefore correlated with softening. The results indicate that fruit softening may be physically associated with the stress-relaxation parameter, T(0), and the extent of softening is a function of position within the fruit. Decreases in T(0) value appear to be correlated with the reported regional variation in the appearance of polygalacturonase.

Journal Article↗
PubMed1991

Culm Brittleness of Barley (Hordeum vulgare L.) Mutants Is Caused by Smaller Number of Cellulose Molecules in Cell Wall.

The physicochemical nature of the cell wall was determined in the fourth internode of three isogenic brittle mutants of barley (Hordeum vulgare L.) and corresponding nonbrittle strains. Cellulose contents of the brittle culms were 17.5 to 20.3% of those of corresponding nonbrittle strains. No major difference was found in lignin and noncellulose components (except glucose) between brittle and nonbrittle strains. Maximum bending stresses of brittle culms were 38.0 to 54.2% of those of corresponding nonbrittle strains. The degree of polymerization of cellulose, measured by viscometry, was similar between the brittle and the nonbrittle strains. Mole number of cellulose molecules in a unit length of brittle culms, calculated by dividing cellulose mass by molecular weight, was 7.7 to 17.3% of those of the nonbrittle strains. These results indicate that brittleness of mutant culms is due to fewer numbers of cellulose molecules in the cell walls.

Journal Article↗
PubMed1991

A pathologic study on the inhibitory effects of a herbal medicine against the glomerular lesion induced by Agkistrodon venom in mice.

The inhibitory effects of a prescription of herbal medicine, tentatively named P-3, were studied pathologically in an experimental model of the glomerular lesion induced by purified snake Agkistrodon acutus venom proteinase (Ac1-P) in mice. Ac1-P was intravenously inoculated at a single LD50 dose. In the treated group, mice were intraperitoneally injected with an extract of P-3 at a designated time once every two days from 2 days before to 1 week after Ac1-P inoculation. The control group mice were injected with saline instead of P-3. In the control group, the main pathologic changes within 48 hrs after inoculation were pulmonary and gastrointestinal tract hemorrhage and renal petechiae with hematuria. The kidney microscopically showed cystic transformation of the glomerular capillary tufts. followed by occlusive thrombosis. One week after inoculation, the glomerular lesions were mostly replaced by proliferative or proliferative-sclerosing changes with occasional crescent formation. Early signs of tubular atrophy accompanying the glomerular changes were observed. In the P-3 treated mice surviving 48 hrs and 1 week, the changes observed in the controls were markedly inhibited, although P-3 treated mice dying earlier than 30 hrs exhibited hemorrhagic changes similar to controls. This indicated that the herbal medicine had efficacy against the tissue injuries induced by Ac1-P as a proteolytic enzyme.

Angiography↗
PubMed1991

Application of renal microangiography to normal and diseased kidneys of cattle and mice.

Use of microangiography is now essential for the study of microcirculation in various organs. Renal microangiographic studies have been reported in rats, rabbits, dogs, human beings, and mice. However, we could not find any report on use of the technique in cattle, despite high incidence of renal disease in that species. The perfusion technique used in mice was improved over that of our previous report, and was applied to normal and diseased bovine kidneys. For the microangiographic technique, composition of the contrast medium, pressure of the injection, duration of perfusion, and washing of kidneys with heparinized saline solution before perfusion are important. In cattle, 1- to 2-mm-thick sections of the kidneys were generally necessary to observe renal vasculature: arcuate and interlobular arteries, afferent arterioles, and glomerular capillaries. In normal bovine kidneys, the angiographic and microangiographic findings were easily recognized as normal, compared with those of normal mice. In affected bovine kidneys, which histologically represented glomerulonephritis and pyelonephritis, angiography and microangiography revealed corresponding findings.

Angiography↗
PubMed1990

Reference values of hemostasis related factors of healthy Japanese adults. I: Circadian fluctuation.

The circadian fluctuation of hemostasis related parameters was examined on 16 healthy Japanese adults (male 9, female 7). Twenty one parameters were measured in this study, i.e. fibrinogen, the activity of F.II, F.V., F.VII, F.VIII, F.IX, F.X., F.XI, F.XII, antithrombin III, plasminogen, alpha 2-antiplasmin, as well as the antigen level of F.IX, von Willebrand Factor, protein C, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), beta-thromboglobulin, platelet factor 4, fibrinopeptide A, plasmin-alpha 2-antiplasmin complex and FDP. Fluctuation was not significant in almost all of the parameters except F.VIII, F.IX, beta-thromboglobulin, platelet factor 4, tPA and PAI-1. Although the fluctuations of F.VIII, F.IX, beta-thromboglobulin and platelet factor 4 were statistically significant, they remained within the normal ranges. On the other hand, tPA and free PAI-1 showed significant circadian fluctuation, of which levels were highest at 9:00. It was postulated that the significant circadian fluctuation of fibrinolytic activity will be regulated by the balance between tPA and PAI-1 in plasma.

Adult↗
PubMed1990

Clinical observations of children with pleuropneumonia due to Mycoplasma pneumoniae.

A comparative study on the clinical presentation of Mycoplasma pneumoniae infection was performed in 56 patients with pleuropneumonia and those who had pneumonia without pleural effusion. The latter consisted of 773 cases; their age distribution reached a peak at 3-5 years of age in males and at 4-6 years in females. The 56 cases with pleuropneumonia were distributed among children of all ages. Pneumococcal infection was demonstrated by blood culture in one of 56 cases. Serological tests revealed a higher prevalence of mixed viral infections among children with pleuropneumonia (18/44) than with pneumonia but no effusion (69/419). There was a tendency toward a severe and prolonged course of illness with strong indications of infection among pleuropneumonia cases. Complications such as exanthema or liver dysfunction were observed more frequently among pleuropneumonia cases than among simple pneumonia cases. These results suggest that other pathogenic agents or unknown host reactions to these agents may modify the clinical picture of pleuropneumonia caused by M. pneumoniae.

Child↗
PubMed1990

Transmission of Chlamydia pneumoniae in young children in a Japanese family.

Chlamydia pneumoniae strain TWAR was isolated from the respiratory tract of a 5-year-old girl suffering from pneumonia. The IgM and IgG antibody titers to TWAR were 1:32 and 1:128, respectively. Cultures and serology for other common bacterial and viral respiratory pathogens were negative. Although she was treated with 35 mg/kg/day rokitamycin, TWAR was repeatedly isolated after treatment. Her 3-year-old sister developed acute bronchitis, and TWAR was isolated from her nasopharynx. She was treated with 43 mg/kg/day erythromycin with prompt improvement, and TWAR was not isolated after treatment. Although her mother, grandmother, and 8-month-old sister suffered from respiratory illness during these periods, TWAR was not isolated from them. The repeated isolations from the index patient suggest that infection was transmitted from sister to sister. This case represents the first reported isolation of TWAR from young children in the same household and the first from Japan.

Adult↗
PubMed1990

Sugar Composition and Molecular Weight Distribution of Cell Wall Polysaccharides in Outer and Inner Tissues from Segments of Dark Grown Squash (Cucurbita maxima Duch.) Hypocotyls.

The elongation growth of stem segments is determined by the outer cell layers (epidermis and collenchyma). We measured the sugar composition and molecular weight distribution of pectin and hemicellulose fractions obtained from inner and outer tissues of squash (Cucurbita maxima Duch.) hypocotyls. In addition, we studied the changes in these parameters after a 9 hour period of incubation of the segments. The results show that outer tissues have higher molecular weight pectin and hemicellulose compared to inner tissues (2-3 times higher). Incubation results in a 13 to 25% decrease in the amount of pectin and hemicellulose in inner tissues and an increase of 11 to 32% in the outer tissues. This increase in the outer tissues is accompanied by a decrease in the molecular weight of some of the components. These results clearly show that cell wall metabolism during elongation growth differs markedly in inner and outer tissues, and that future studies on the effect of auxin need to take these differences into account.

Journal Article↗
PubMed1990

[Studies on chemical protectors against radiation. XXX. Radioprotective substances of cnidii rhizoma].

Radiation protective effects of the methanol extract and its fractions of Cnidii Rhizoma on lethality and skin injury induced by X-irradiation were studied. As a result of these studies, it was observed that significant protective effects exist in both ether and water soluble portions prepared from the above methanol extract, and two of the active principles in the ether and water soluble ones were identified as ferulic acid and adenosine, respectively.

Adenosine↗
PubMed1990

[Protective effects of various methanol extracts of crude drugs on experimental hepatic injury induced by carbon tetrachloride in rats].

The protective effects of 67 methanol extracts of crude drugs on rat hepatic injury by carbon tetrachloride (CC14) were examined. In terms of the release of intrahepatic enzymes and bilirubin into the blood, 11 methanol extracts decreased these factors significantly. Among them methanol extracts of Caryophylli Flos, Angelicae Dahuricae Radix, Polygoni Avicularis Herba, Myricae Cortex and Forsythiae Fructus were newly found to have protective effects against acute hepatic injury induced by CCl4. And then these 11 extracts which protected hepatic injury by CCl4 were investigated for their membrane stabilizing and inhibitory effects of lipid peroxidation. The extract of Bupleuri Radix only decreased the hemolysis induced by hypotonic pressure. Nine kinds of extracts without those of Desmodii Herba and Bupleuri Radix suppressed the lipid peroxidation induced by CCl4 in rat hepatic microsomes. In addition, Scutellariae Radix, Caryophylli Flos and Myricae Cortex were shown to have inhibitory effects of non-enzymatic lipid peroxidation in rat hepatic mitochondria. This study reports that the methanol extracts of Caryophylli Flos, Angelicae Dahuricae Radix, Polygoni Avicularis Herba, Myricae Cortex and Forsythiae Fructus protect the hepatic injury by CC14 and these protective effects are connected with the inhibitory effects of the lipid peroxidation in hepatic microsomes.

Animals↗