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Biomedical subjects

S Kawano

Publications and source records attributed to S Kawano.

At least 271 records · Page 15Linked to original sources
PubMed1993

Comparison of infrared electronic endoscopy using reflection and transmission.

Twelve subjects were examined using both the reflecting type of infrared electronic endoscopy and the transmission method to visualize submucosal gastric architecture. Under transmission infrared illumination, submucosal structures were more clearly observed than by using the reflecting type. Using the transmission method, only the anterior wall of the antrum could be fully visualized, although the anterior wall of the lower corpus was recognized in only 33% of the cases. Furthermore, the upper or middle corpus and the entire posterior wall were not properly recognized using transmission illumination. The entire gastric circumference was visualized with the reflecting type illumination. Both types of infrared illumination of the gastric wall can be used complementarily for visualizing submucosal gastric architecture.

Aged↗
PubMed1993

Pattern of expression of CD45 RA/RO isoformic antigens in acute myeloblastic leukemia cells.

The authors used cell surface immunofluorescence to investigate the expression of CD45 RA (4KB5)/RO (UCHL1) antigen by acute myeloblastic leukemia (AML) cells from 78 patients. Four types--RA+/RO- (RO < 15%), RA-/RO+ (RA < 15%), mixed (20% RA and 20% RO), and RA-/RO- (RA < 10% and RO < 10%)--were observed. The number of cases with RA+/RO-, RA-/RO+, mixed, and RA-/RO- types in each French-American-British subclass of AML were as follows: M1 (n = 22): 18, 4, 0, 0; M2 (n = 21): 16, 0, 5, 0; M3 (n = 14): 11, 0, 0, 3; M4: 2, 2, 1, 0; and M5: 5, 5, 6, 0, respectively. The M1 RA-/RO+ type, which was always CD7- CD34- HLA-DR-, constituted a rare and distinct M1 subtype because there was no mixed type among the M1 cases. All CD7+ AML cells were the RA+/RO- type and HLA-DR+ except one. The expression of CD45 RO antigen, found in patients with M2, M4, and M5 subtypes of AML, was thought to be associated with the maturity of blasts as monocyte or granulocyte lineage cells. CD45 antigen has tyrosine phosphatase activity in association with nonreceptor-type tyrosine kinases. It was speculated that the functional status and stage of differentiation of the granulocyte/monocyte lineage determine which type of nonreceptor-type tyrosine kinases will operate, which then select the pattern of expression of the CD45 isoform. Thus, the determination of tyrosine kinases associated with CD45 isoforms seems to be important in understanding the AML subsets defined by the pattern of CD45 RA/RO expression.

Adolescent↗
PubMed1993

A genetic system controlling mitochondrial fusion in the slime mould, Physarum polycephalum.

We have identified two distinct mitochondrial phenotypes, namely, Mif+ (mitochondrial fusion) and Mif- (mitochondrial fusion-deficient), and have studied the genetic system that controls mitochondrial fusion in the slime mould, Physarum polycephalum. A mitochondrial plasmid of approximately 16 kbp was identified in all Mif+ plasmodial strains. This plasmid is apparently responsible for promoting mitochondrial fusion, and it is inserted into the mitochondrial DNA (mtDNA) in successive sexual crossing with Mif- strains. This recombinant mtDNA and the unchanged free plasmid spread through the mitochondrial population via the promotion of mitochondrial fusion. The Mif+ strains with the plasmid were further classified as being two types: high frequency and low frequency mitochondrial fusion. Restriction analysis of the mtDNA suggested that the high frequency mitochondrial fusion type was more often heteroplasmic; within each plasmodium, mtDNAs of both parental types were usually present, in addition to the presence of the plasmid. Genetic analysis with the progeny obtained from crossing myxamoebae derived from three different isolates suggested that these progeny carried different alleles at a nuclear locus that controlled the frequency of mitochondrial fusion. These alleles (mitochondrial mating-type alleles, mitA1, 2 and 3) appear to function like the mating type of the myxamoebae; mitochondrial fusion occurs at high frequency with the combination of unlike alleles, but at low frequency with the combination of like alleles.

Alleles↗
PubMed1993

Measurement of redox states of mitochondrial cytochrome aa3 in regions of liver lobule by reflectance microspectroscopy.

To evaluate the sublobular distribution of oxygen tension, the redox states of mitochondrial cytochrome aa3 were assessed in local regions of the liver lobule by reflectance microspectroscopy. The reflected light from two focused microspots (20 microns in diam) on the surface of the perfused liver, placed on the stage of microscope, was conducted to the spectrophotometer with two separate light guides, giving the reflectance spectra. The redox state of cytochrome aa3 was calculated from the difference in reflectance between 603 and 630 nm. The degree of cytochrome reduction increased with the stepwise decline of the influent or effluent oxygen concentrations. The local oxygen concentration in periportal region for the half-maximal reduction of cytochrome aa3 was higher than that in pericentral region. In addition, the degree of cytochrome aa3 reduction increased with the distance from the periportal region, reflecting a physiological gradient of oxygen tension along the sinusoidal flow, although with an intersinusoidal heterogeneity within liver lobule.

Animals↗
PubMed1993

Role of endogenous endothelin in pathogenesis of ethanol-induced gastric mucosal injury in rats.

The major objective of this study was to elucidate the role of endogenous endothelin (ET)-1, a potent vasoconstrictor peptide, in the pathogenesis of ethanol (EtOH)-induced gastric mucosal injury. Two series of experiments were performed in anesthetized rats. First, we examined the time course of relationships among changes in ET-1 concentrations in gastric mucosal and portal plasma, gastric mucosal hemodynamics, and mucosal damage produced by EtOH. Intragastric EtOH stimulated release of endogenous ET-1 in gastric mucosal tissue. Plasma ET-1 concentrations in the portal vein also increased after intragastric EtOH administration. ET-1 concentrations in gastric mucosal tissue and portal plasma increased significantly before gastric mucosal hemorrhagic damage occurred. Moreover, 30 min after EtOH administration there were significant correlations between gastric mucosal ET-1 concentrations and both area of gastric hemorrhagic damage as well as concentration of EtOH administered intragastrically. After intragastric EtOH administration, increase in gastric mucosal hemoglobin concentration and decrease in gastric mucosal hemoglobin oxygen saturation, estimated using reflectance spectrophotometry, occurred within 2.5 min and continued throughout the experiments. The time course of microcirculatory changes correlated closely with increases in gastric mucosal ET-1 and portal plasma ET-1 concentrations after intragastric EtOH administration. Gastric microcirculatory disturbances induced by EtOH were associated with significant decreases in gastric mucosal ATP content. Second, we examined whether pretreatment with anti-ET-1 antibody protected against EtOH-induced mucosal injury by improving mucosal microcirculation. Pretreatment with anti-ET-1 antibody microscopically and macroscopically reduced gastric mucosal hemorrhagic damage induced by EtOH and significantly reduced EtOH-induced gastric microcirculatory disturbances and decreases in gastric mucosal ATP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Axial length of eyes with rhegmatogenous retinal detachment.

We conducted a prospective study of 226 eyes with nontraumatic rhegmatogenous retinal detachment; we examined patient characteristics as well as changes in axial length and corneal curvature induced by scleral buckling surgery. Eyes with a round hole in lattice degeneration were characterized by axial length that was longer than that of eyes with retinal tears with and without lattice degeneration. Sex and age also correlated significantly with axial length. Surgically induced changes in axial length depended upon the procedures performed, but the retinal detachment surgery primarily caused a change in the refractive status.

Adult↗
PubMed1993

Protein kinase A-activated chloride channel is inhibited by the Ca(2+)-calmodulin complex in cardiac sarcoplasmic reticulum.

Cardiac sarcoplasmic reticulum (SR) has several chloride (Cl-) channels, which may neutralize the charge across the SR membrane generated by Ca2+ movement. We recently reported a novel 116-picosiemen Cl- channel that is activated by protein kinase A-dependent phosphorylation in cardiac SR. This Cl- channel may serve as a target protein in the receptor-dependent regulation of cardiac excitation-contraction coupling. To understand further regulatory mechanisms, the effects of Ca2+ on the Cl- channel were studied using the planar lipid bilayer-vesicle fusion technique. In the presence of calmodulin (CaM, 0.1 mumol/L per microgram SR vesicles), Ca2+ (3 mumol/L to 1 mmol/L) added to the cis solution reduced the channel openings in a concentration-dependent fashion, whereas Ca2+ (1 nmol/L to 1 mmol/L) alone or CaM (0.1 to 1 mumol/L per microgram SR vesicles) with 1 nmol/L Ca2+ did not affect the channel activity. This inhibitory effect of Ca2+ in the presence of CaM was prevented by CaM inhibitors N-(6 aminohexyl)-5-chloro-1-naphthalenesulfonamide and calmidazolium but not by CaM kinase II inhibitor KN62. These results suggest that the Ca(2+)-CaM complex itself, but not CaM kinase II, is involved in this channel inhibition. Thus, the cardiac SR 116-picosiemen Cl- channel is regulated not only by protein kinase A-dependent phosphorylation but also by the cytosolic Ca(2+)-CaM complex. This is a novel second messenger-mediated regulation of Cl- channels in cardiac SR membrane.

Animals↗
PubMed1993

Roles of endothelin-1 and nitric oxide in the mechanism for ethanol-induced vasoconstriction in rat liver.

This study was designed to investigate the mechanism for ethanol-induced hepatic vasoconstriction in isolated perfused rat liver. Upon initiation of ethanol infusion into the portal vein at concentrations ranging from 25 to 100 mM, portal pressure began to increase in a concentration-dependent manner and reached maximal levels in 2-5 min (initial phase), followed by a gradual decrease over the period of ethanol infusion (escape phenomenon). Endothelin-1 antiserum significantly inhibited this ethanol-induced hepatic vasoconstriction by 45-80%. Cessation of infusion of endothelin-1 antiserum was followed by a subsequent increase in portal pressure. On the other hand, when a nitric oxide synthesis inhibitor, NG-monomethyl-L-arginine (L-NMMA), was infused into the portal vein simultaneously with ethanol, the initial phase of the response of portal pressure to ethanol was not altered and the peak values of portal pressure remained unchanged. However, after the peak increase in portal pressure, the rate of decrease was less than in the absence of L-NMMA. Thus, L-NMMA diminished the escape phenomenon and sustained the vasoconstriction. This study supports the hypothesis that two endothelium-derived vasoactive factors, endothelin-1 and nitric oxide, regulate hepatic vascular tone in the presence of ethanol.

Animals↗
PubMed1993

The body surface QRST isointegral maps in infants with right ventricular overload.

Electrocardiographic criteria for right ventricular (RV) hypertrophy in infants generally exhibit low sensitivity in terms of diagnostic accuracy. We studied the QRST isointegral map (QRST-Imap) of body surface potential distribution for the diagnosis of RV overload in patients less than 2 years old. Patients with atrial septal defect (ASD), pulmonary stenosis (PS) and tetralogy of Fallot (TOF) were examined (RV overload group) and the findings of their QRST-Imaps were compared to those of age-matched healthy infants (NOR). QRST-Imaps in RV overload showed abnormal findings, with two maxima or a rightward shift of the maximum with increased amplitude, in contrast to one maximum at the left anterior chest with a single dipole pattern in the NOR group. ASD patients had two maxima with a decreased integral value between them. In PS, two maxima were also observed, with increased integral values of the right maximum as the RV systolic pressure was elevated. TOF patients showed a single maximum shifted to the anterior median line with increased amplitude. These results indicate that the findings of QRST-Imaps are of value in detecting the presence and pattern of RV overload in infants.

Electrocardiography↗
PubMed1993

Esophageal squamous cell papilloma, suspected of squamous cell carcinoma.

A 46-year-old male without any subjective complaints was diagnosed by radiography as having one polypoid lesion at the distal esophagus. Endoscopy indicated a semipedunculated polyp about 1 cm in size, the specimens of which included atypical cells with a high N/C ratio in the submucosa. Squamous cell carcinoma of the esophagus was suspected. Cytological studies of PAS, CEA and keratin staining to atypical cells were all negative, with Lugol solution staining of the tumor. After polypectomy the lesion was diagnosed as a squamous cell papilloma of the esophagus; and the atypical cells were determined to be immature fibroblasts and/or endothelium.

Carcinoma, Squamous Cell↗
PubMed1993

Natural killer cell activity in herpes zoster in children without underlying disease.

We determined natural killer cell (NKC) activity in 10 otherwise normal children with herpes zoster. NKC activity values in children with vs. without varicella-zoster virus specific IgM antibodies and in controls were 28.3 +/- 8.6%, 11.9 +/- 3.6% and 20.2 +/- 3.8% (mean +/- SD), respectively. There were significant differences between the children with and without IgM antibodies during the acute phase (p < 0.005) and between children without IgM antibodies and controls (p = 0.005). NKC values in children with mild vs. moderate morbidity were 11.7 +/- 4.1% and 25.7 +/- 9.9%, respectively (p < 0.05). The morbidity was moderate in all children with IgM antibodies, but in only 2 of the 5 children without IgM antibodies. Children who contracted varicella when a few months old had the highest IgM antibody titers and the highest value of NKC activity. NKC activity was related both to the presence of IgM antibodies and to the morbidity of herpes zoster.

Adolescent↗
PubMed1993

Proliferative response to varicella-zoster virus is inverse related to development of high levels of varicella-zoster virus specific IgG antibodies.

We examined specific humoral and cellular immunity from varicella-zoster virus (VZV) in 10 pediatricians, 8 healthy immune adults, 2 non-immune adults, and 15 patients with acute lymphocytic leukemia (ALL) in order to investigate the mechanism of resistance to VZV and the booster effect of frequent re-exposure. The responder cell frequency (RCF) against VZV antigen was determined by lymphoproliferative response with limiting dilution. Four of the 10 children with ALL and receiving maintenance therapy did not have VZV-specific cellular immunity according to our positive criteria (Stimulation Index > 2.0 and RCF > 1:150,000), but 3 of these 4 patients had VZV-specific IgG antibody. In both healthy adults and ALL patients re-exposure to VZV or reactivation of the virus enhanced VZV-specific immunity. Individuals with very high RCF values (> 1:10,000) had the lowest IgG antibody titers.

Adolescent↗
PubMed1993

Urinary excretion of stress hormones of rats in tail-suspension.

Tail-suspension of rats has been employed for the study of disuse atrophy of hindlimb muscles and bones. From our study, it is suggested that stress exacerbates muscle and bone atrophy; however, the determination of stress hormones has been inappropriately performed. For assessing the effect of tail suspension on stress hormone secretion, suspension was performed for 7 days in a metabolic cage. Urinary excretions of corticosterone, catecholamines and antidiuretic hormone were determined during the 7-day suspension. Urine volume was unchanged during the suspension period, whereas water consumption was decreased during suspension. Urinary excretion of corticosterone and catecholamines increased significantly during the initial 3 days of suspension. The excretion of antidiuretic hormone increased throughout the suspension period. Our results demonstrated that the determination of urinary excretion of these hormones is useful for evaluating the stress reaction.

Adrenal Glands↗
PubMed1993

Suppression of gene expression of myeloperoxidase (MPO) by gamma-interferon (IFN-gamma) in HL60 cells.

The gene expression of myeloperoxidase (MPO) in HL60 cells, as tested by Northern blot analysis with a MPO gene probe, was markedly suppressed at 9 h after the addition of gamma-interferon (IFN-gamma) (200 U/ml), whereas cytochemically detected MPO activity, cell surface antigen expression, and cell morphology remained unchanged even at 48 h. IFN-gamma of 50 U/ml was sufficient for the suppression at 24 h. When the HL60 cells treated with IFN-gamma (200 U/ml) for 24 h were cultured in the absence of IFN-gamma for another 24 h, the transcript of MPO gene reverted to a level comparable to that of the HL60 cells cultured thoroughly in the absence of IFN-gamma, indicating the reversibility of the suppression. The suppression of MPO expression at RNA level, probably independent of differentiation, is a biological activity exerted by IFN-gamma, which has not been previously reported.

Cell Line↗
PubMed1993

[Cytokine in phenotypic analysis of leukemia/lymphoma: suppression of gene expression of myeloperoxidase by IFN-gamma and subset of AML M1 defined by CD45RO+/RA-, CD7(-), CD34(-) and non-inducible HLA-DR antigen].

One of 8 to 12 pre-B ALL cells co-express CD13 and CD33 antigens, but such blasts do not express myeloperoxidase (MPO) even on electronmicroscopy or mRNA. MPO+ pre-B ALL is extremely rare (1/50-1/100), however a cell-line (Tahr87) was established in culture. In contrast, T-lineage blasts express CD13/33 antigens regularly in the pro-thymic stage (CD7+ 5+ 2+ 3- 4- 8- or more immature), and a limited expression of MPO is rather commonly detected particularly in recurrences. The co-expression of CD3 epsilon/MPO or CD3 epsilon/delta/MPO mRNA has been demonstrated. Thus, the regulation of MPO expression is of utmost importance in interpreting the phenotypes of leukemia/lymphoma. While testing the effects of several cytokines on MPO expression, IFN-gamma was found to suppress the gene expression of MPO in HL60 cells. This suppression was not accompanied by differentiation, termination of proliferation or reduction of cytochemical MPO+ cells, and was reversible. Among 22 cases of M1 AML blasts, 8 cases were HLA-DR(-). DR antigen was induced by the presence of a mixture of IFN-gamma, TNF-alpha and TPA in 4 cases, but not in the other 4 cases. The blasts of the latter 4 cases were always CD34(-), CD7(-) and CD45RA-/RO+, and constituted a distinct M1 subset which has not previously been reported.

Antigens, CD↗
PubMed1993

[Phenotypic analysis of immature T-lineage cells].

The characteristics of very immature T-lineage blasts including co-expression of myeloid properties and the distinctions between the phenotypes of pro-thymic (CD7+ CD5+ CD2+ CD3- CD4- CD8- or more immature) and thymic (CD3- CD4+ CD8+ or more mature) blasts are shown. The lineage-derivation of CD7+ CD5- CD2- and CD7+ CD5+ CD2- lymphoid blasts was investigated based on the gene expression of CD3 epsilon, CD3 delta and myeloperoxidase (MPO). The former group included 4 categories; undifferentiated blasts without commitment to myeloid or T-lineage, T-lineage blasts with mRNA of CD3 epsilon, T/myeloid blasts with mRNA of CD3 epsilon and MPO and blasts with mRNA of MPO. The latter included 2 categories; T-lineage blasts with CD3 epsilon and CD3 delta mRNA and T/myeloid blasts with CD3 epsilon, CD3 delta and MPO mRNA. Thus, CD3 epsilon was expressed at a more immature stage than CD3 delta. The blasts at the pro-thymic stage were different from those at the thymic stage in several respects. The T-cell receptor (TCR) beta-chain gene showed a germ-line configuration in most pro-thymic blasts. The CD13/CD33, CD11b and class II MHC antigens were expressed very frequently in the pro-thymic stage. The CD21 antigen was most selectively expressed at the thymic stage. Pro-thymic blasts were of RA type of CD45 antigen, while thymic blasts were of RO type. Recombination activation gene-1 (RAG-1) was only limitedly expressed at the pro-thymic stage, but was highly expressed at the thymic stage. These findings indicate that there are distinctive differences before and after the initiation of clonal selection which is unique and thymus-specific, and that the neoplastic cells represent each stage of T-lineage differentiation involving the unique thymic function.

Antigens, Surface↗
PubMed1993

[Activity of Lansoprazole (new proton pump inhibitor) against Helicobacter pylori and its therapeutic efficacy].

Lansoprazole, one of PPIs, is a strong antacid and it cures stomach and duodenal ulcers at early stages as well as having antibiotic action towards HP. The in vitro MIC of the product is between 3.13 and 12.5 micrograms/ml and it was 12.5 micrograms/ml, which was the same as MIC of colloidal bismuth citrate, in our study. Sterilizing effect of Lansoprazole is reported to be the direct attack on HP bacteria from electron microscopic findings. Our study revealed that Lansoprazole would preserve the epithelial cells on the edge of a stomach ulcer and would protect PAS-positive substance within them. Lansoprazole is said to cure many H2-Blocker resistant ulcers and to suppress the rate of recurrence of stomach and duodenal ulcers. These effects are considered to be attributable to maintenance of mucous barrier and maintenance of cytoprotection of the gastric mucosa by Lansoprazole as well as its sterilizing action mainly on HP.

2-Pyridinylmethylsulfinylbenzimidazoles↗