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Biomedical subjects

M Sugawara

Publications and source records attributed to M Sugawara.

At least 145 records · Page 8Linked to original sources
PubMed1997

Premenstrual mood changes and maternal mental health in pregnancy and the postpartum period.

To investigate the relationship between premenstrual mood changes and maternal mental health in the perinatal period, a prospective questionnaire survey of 1,329 women was carried out. Women with a premenstrual mood changes (irritability) before pregnancy showed significantly higher Zung's Self-rating Depression Scale (SDS) scores than those without it, throughout pregnancy and the postpartum period (6 time points: early, middle, and late pregnancy, 5 days, 1 month, and 6 months after childbirth). In addition, women with premenstrual irritability had greater anxiety about pregnancy and delivery, were more reluctant to accept mother roles, and felt their babies (fetuses or neonates) were more vulnerable. These findings suggest that premenstrual mood change is correlated with unstable mental health throughout the perinatal period.

Adolescent↗
PubMed1997

Receptor based chemical sensing.

This mini-review describes our recent approach of mimicking transmembrane and intracellular signalings displayed by various receptors in biomembranes for the development of new sensing membranes. Several important modes of receptor signaling have been utilized exploiting bio and synthetic receptors; (i) Ca2+ signaling by calmodulin, (ii) active transport of target and relevant compounds displayed by Na+/D-glucose cotransporter and Na+,K(+)-ATPase, (iii) membrane permeability changes induced by glutamate receptor ion channel proteins and (iv) membrane potential changes induced by synthetic receptors. The newly designed sensing systems are demonstrated and discussed in terms of their novel mode of signal transduction, sensitivity and selectivity.

Biological Transport↗
PubMed1997

Disopyramide improves the balance between myocardial oxygen supply and demand in patients with hypertrophic obstructive cardiomyopathy.

We evaluated the effects of disopyramide in terms of the balance between myocardial oxygen supply and demand in patients with hypertrophic obstructive cardiomyopathy (HOCM). The myocardial oxygen supply was evaluated by measuring coronary flow velocity and the myocardial oxygen demand was assessed by the pressure-volume area (PVA). The time velocity integral of coronary flow did not change significantly (20 +/- 6 to 21 +/- 8 cm), but the peak left ventricular pressure and left ventricular external work decreased significantly (206 +/- 44 to 157 +/- 37 mmHg, P < 0.001; 1.09 +/- 0.33 to 0.80 +/- 0.23 J/beat, P < 0.001) after disopyramide administration. From theoretical analysis using these data, we concluded that disopyramide improves the myocardial oxygen supply-demand balance in patients with HOCM.

Adult↗
PubMed1997

Analysis of helicase gene mutations in Japanese Werner's syndrome patients.

The profile of helicase gene mutations was studied in 89 Japanese Werner's syndrome (WRN) patients by examining the previously described mutations 1-4 as well as a new mutation found during this study, designated mutation 5. Of 178 chromosomes (89 patients), 89 chromosomes (50%) had mutation 4, 11 (6.2%) chromosomes had mutation 1, and two chromosomes (1.1%) contained mutation 5. Mutations 2 and 3 were not observed in this patient population. The remaining 76 (42.7%) chromosomes had none of these mutations. A significant fraction of all patients (22 total patients, 24.7%) appear to be compound heterozygotes, including those carrying mutations of both types 1 and 4. The genotypes analysis of the markers surrounding the. WRN helicase gene strongly suggests that most of the chromosomes carrying either mutation 1 or 4 were derived from two single founders.

DNA Helicases↗
PubMed1997

A novel missense mutation in exon 4 of the human coproporphyrinogen oxidase gene in two patients with hereditary coproporphyria.

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase. To date, four mutations of the gene have been reported. We report here another mutation in two Japanese families with HCP, which was revealed by analysis of polymerase chain reaction (PCR)-amplified DNA fragments of the gene by a direct-sequencing method. A point mutation, G to A, was found in exon 4 of the gene at position 538 of the cDNA from the reported putative translation initiation codon ATG. This mutation results in a glycine to arginine substitution at amino acid 180. Two carriers in the family were successfully diagnosed by detecting the mutation using restriction analysis of the PCR products.

Adult↗
PubMed1997

Mutation and haplotype analyses of the Werner's syndrome gene based on its genomic structure: genetic epidemiology in the Japanese population.

The correlation between mutations in the Werner's syndrome (WRN) gene and the haplotypes of surrounding markers was studied in Japanese patients. We have elucidated the genomic structure of WRN helicase, and found five additional mutations, designated mutations 6-10. Mutations 4 and 6 were found to be the two major mutations in this population; these mutations comprised 50.8% and 17.5%, respectively, of the total in a sample of 126 apparently unrelated chromosomes. Almost all the patients homozygous for mutation 4 shared a haplotype around the WRN gene, consistent with the view that they are derived from a single ancestor. This important advantage demonstrated in the identification of the WRN gene suggests that the Japanese present a unique population for the cloning of other disease genes. The conserved haplotype was observed across 19 loci, extending a distance estimated to be more than 1.4 Mbp around the WRN gene. This haplotype is rare among random Japanese individuals. Unexpectedly, all the nine patients homozygous for mutation 6 shared a haplotype that was identical to this haplotype at 18 of these 19 markers. These results suggest that mutations 4 and 6 arose independently in almost identical rare haplotypes. The remaining mutations (1, 5, 7, 8, 9, and 10) occurred rarely, and were each associated with different haplotypes.

DNA Helicases↗
PubMed1997

Aortic blood momentum--the more the better for the ejecting heart in vivo?

OBJECTIVES: The aim of the present study was to test two hypotheses: (1) the momentum of the blood flowing out of the left ventricle toward the aorta (inertia force) plays an important role in the initiation of decay and the maximum rate of decay (peak (-dP/dt)) of left ventricular pressure (P); (2) a normal heart itself generates the inertia force which enhances its function. METHODS: The contribution of the inertia force to (-dP/dt) was theoretically given as rho c alpha, where rho is the blood density, c the pulse wave velocity, and alpha the deceleration rate of aortic blood flow. The correlations of peak (-dP/dt) with rho c alpha and with the time constant (tau) of the pressure decay during isovolumic relaxation, which was considered to represent myocardial relaxation characteristics, were compared in seven dogs. We developed a method of grading the strength of the inertia force, using the phase loop of left ventricular pressure (dP/dt vs. P relation). The method was applied to the records of 25 patients with ischemic heart disease, from which high fidelity left ventricular pressure recordings were available. RESULTS: The correlation of peak (-dP/dt) with rho c alpha was much higher than with tau (0.75 vs. -0.46). 16 of the 25 patients showed evidence of the inertia force. However, other patients showed no inertia force. The strength of the inertia force showed a significant (P < 0.05) correlation with left ventricular end-diastolic pressure (r = -0.46), cardiac index (r = 0.62), stroke volume index (r = 0.69), ejection fraction (r = 0.46), and peak (-dP/dt) (r = 0.56). CONCLUSION: The inertia force of late systolic aortic flow contributed to ventricular relaxation in the normal heart.

Aged↗
PubMed1997

Electrochemical evaluation of chemical selectivity of glutamate receptor ion channel proteins with a multi-channel sensor.

A new method for evaluating chemical selectivity of agonists towards receptor ion channel proteins is proposed by using glutamate receptor (GluR) ion channel proteins and their agonists N-methyl-D-aspartic acid (NMDA), L-glutamate, and (2S, 3R, 4S) isomer of 2-(carboxycyclopropyl)glycine (L-CCG-IV). Integrated multi-channel currents, corresponding to the sum of total amount of ions passed through the multiple open channels, were used as a measure of agonists' selectivity to recognize ion channel proteins and induce channel currents. GluRs isolated from rat synaptic plasma membranes were incorporated into planar bilayer lipid membranes (BLMs) formed by the folding method. The empirical factors that affect the selectivity were demonstrated: (i) the number of GluRs incorporated into BLMs varied from one membrane to another; (ii) each BLM contained different subtypes of GluRs (NMDA and/or non-NMDA subtypes); and (iii) the magnitude of multi-channel responses induced by L-glutamate at negative applied potentials was larger than at positive potentials, while those by NMDA and L-CCG-IV were linearly related to applied potentials. The chemical selectivity among NMDA, L-glutamate and L-CCG-IV for NMDA subtype of GluRs was determined with each single BLM in which only NMDA subtype of GluRs was designed to be active by inhibiting the non-NMDA subtypes using a specific antagonist DNQX. The order of selectivity among the relevant agonists for the NMDA receptor subtype was found to be L-CCG-IV > L-glutamate > NMDA, which is consistent with the order of binding affinity of these agonists towards the same NMDA subtypes. The potential use of this approach for evaluating chemical selectivity towards non-NMDA receptor subtypes of GluRs and other receptor ion channel proteins is discussed.

Animals↗
PubMed1997

Immortalization of immunologically committed Epstein-Barr virus-transformed human B-lymphoblastoid cell lines accompanied by a strong telomerase activity.

The immunological characteristics and immortalization processes of three EBV-transformed human B-lymphoblastoid cell lines, N0003, N0005 and N6803, with strong telomerase and infinitively proliferating activities are described. The three cell lines were apparently immortalized: they developed a strong telomerase activity at the population doubling levels (PDLs) between 11 and 135, and continued proliferation over 250 PDLs. All the cell lines expressed CD22, CD19 and CD20 antigens. They were uniformly stained with IgM (N0005), IgG (N6803) or IgA (N0003) at early PDLs between 17 and 20, and they secreted the corresponding class of Ig into the medium; the N6803 and N0003 cell lines continued to secrete each class of Ig at decreased levels while the N0005 cell line expressed or secreted virtually no Ig after immortalization. Karyotype analysis of the immortalized cell lines showed that they were derived from a single cell because they shared a set of abnormal chromosomes within each cell population, and two of the cell lines attained clonal characteristics before they developed a strong telomerase activity. These results indicate that the three immortalized cell lines with a strong telomerase activity correspond to the intermediate stages of B-cell differentiation naturally committed to a specific Ig class, and suggest that they were derived from a B-lymphoblastoid cell committed to a specific class of Ig with poor telomerase activity, rather than from a strongly telomerase-positive B-lymphoblastoid cell either committed or multipotential.

B-Lymphocytes↗
PubMed1997

Hyperplastic (metaplastic) polyposis of the colorectum associated with adenomas and an adenocarcinoma.

Hyperplastic (metaplastic) polyposis associated with adenoma and adenocarcinoma of the colorectum is rare. We describe a 55-year-old man with hyperplastic polyposis associated with multiple adenomas and an adenocarcinoma who underwent total colectomy. We found at least 200 polyps in the surgical specimen. Nearly all of the polyps were hyperplastic, and some were adenomas. Furthermore, some hyperplastic polyps had adenomatous areas. This indicates the transformational sequence of a hyperplastic polyp to adenoma to adenocarcinoma.

Adenocarcinoma↗
PubMed1997

The mechanism of excretion of trientine from the rat kidney: trientine is not recognized by the H+/organic cation transporter.

Trientine dihydrochloride is used to treat Wilson's disease by chelating copper and increasing its urinary excretion. The mechanism of renal excretion of trientine has been investigated in-vivo and in-vitro. Trientine clearance in the rat-was significantly faster than creatinine clearance. When trientine and the same number of moles of copper ions were administered simultaneously to the rat, however, trientine clearance decreased to almost the same level as the creatinine clearance. To clarify this active excretion system for trientine, the uptake of trientine and a physiological polyamine compound, spermine, was investigated using rat renal brush-border membrane vesicles. Although, because trientine and spermine are organic cations, the H+/organic cation transporter is expected to recognize these compounds, neither an outwardly directed H+ gradient nor an inward Na+ gradient stimulated trientine uptake. [14C]Spermine uptake was, nevertheless, trans-stimulated by both unlabelled spermine and trientine and the trans-stimulating effect of spermine on trientine uptake was, furthermore, completely abolished by addition of copper ions to the incubation medium. These results suggest that there is a specific transport system for spermine and trientine on the renal brushborder membrane. This transport system contributes to the secretion of trientine in the kidney proximal tubule but does not recognize the trientine-copper complex.

Animals↗
PubMed1997

A structure-relationship study of the uptake of aliphatic polyamine compounds by rat intestinal brush-border membrane vesicles.

The effects of lipophilicity, ion-diffusion potential and membrane surface potential on the uptake of various aliphatic polyamine compounds by rat intestinal brush-border membrane vesicles (BBMV) have been investigated. A valinomycin-induced potassium-diffusion potential (inside-negative) stimulated the initial uptake of diamine compounds, and good correlation was observed between lipophilicity and the amount of diffusion-potential-dependent transport of the diamines. In contrast, because of their much lower lipophilicity, tri- and tetraamine compounds were not affected by the diffusion potential. Tetracaine, which can make the membrane surface potential more positive, inhibited the transport rate of 1,9-nonanediamine, spermidine and spermine by the BBMV. These data suggest that the transport mechanism of diamines is similar to that of monoamine compounds in respect to its dependence on ion-diffusion potential and on the membrane surface potential. The extent of the effect of ion-diffusion potential on the rate of transport of the diamines was closely related to the lipophilicity of the diamine. In contrast, only the surface potential contributed to the transport mechanism of lower lipophilic tri- and tetraamine compounds.

Anesthetics, Local↗
PubMed1997

The effect of membrane surface potential on the permeability of anionic compounds across the apical membrane in human intestinal epithelial (Caco-2) cells.

The effect of membrane surface potential of the apical side on the intracellular uptake of ionic compounds was investigated using the human colon adenocarcinoma cell line (Caco-2). The transepithelial transport of indolepropionic acid and tryptamine was consistent with the uptake behavior shown by rat intestinal brush-border membrane (BBM) vesicles. Imipramine, which diminished the negative charge of the membrane surface (for both Caco-2 and BBM), acted to increase the uptake of the anionic compounds, indolepropionic acid and ceftibuten, and to decrease that of tryptamine (cationic compound) by both the Caco-2 monolayer and the intestinal BBM vesicles at a pH of 7.5. These results suggest that the effects of membrane surface potential on the permeability of ionic compounds were detectable on the Caco-2 cell line as well as the BBM vesicles. On the other hand, the inhibition of H(+)-linked transport and the stimulation of the surface charge-regulated uptake of ceftibuten have occurred simultaneously on the Caco-2 cell line in the presence of imipramine. It seems that the membrane surface charge (negative) plays an important role in the transport process of ionic compounds across the intestinal epithelium.

Adenosine Triphosphate↗
PubMed1997

[A case of reactive arthritis fallen after shigellosis infection].

A 25-year-old woman was admitted for general arthralgia in July, 1989. Reactive arthritis with arthralgia after Shigellosis was diagnosed by sex, localization of arthralgia and positive for HLA-B 27. Within 3 weeks after starting diclifenac sodium 75 mg/day, the arthralgia remitted. It has been reported that patients who are positive for HLA-B 27 have a more severe acute or chronic sacroiliitis, and our case may support this report.

Adult↗
PubMed1997

Early loss of serum hepatitis C virus RNA can predict a sustained response to interferon therapy in patients with chronic hepatitis C.

OBJECTIVES: We evaluated whether the loss of serum hepatitis C virus (HCV) RNA early in interferon (IFN) therapy would indicate a subsequent response to IFN therapy. METHODS: One hundred fourteen patients with chronic hepatitis C were treated with IFN-alpha for 24 weeks. All patients were positive for anti-HCV antibodies and serum HCV RNA. Serum HCV RNA was measured by highly sensitive and specific RT-PCR (modified Amplicor HCV). RESULTS: Of 114 patients who were treated with IFN-alpha for 24 weeks, 22 of 29 patients (75.9%) who lost HCV RNA at the first week of treatment, 5 of 14 patients (35.7%) who lost HCV RNA at the second week, and 2 of 16 patients (12.5%) who lost HCV RNA at fourth week were judged as sustained responder (SR). The SR rate was significantly higher in patients who lost HCV RNA at the first week of therapy (p < 0.05). On the contrary, none of 55 patients who retained HCV RNA during the first 4 weeks of IFN therapy were judged as SR. Concerning the patients who lost HCV RNA at the first week of therapy, there were no significant differences in the SR rate in either HCV genotype (1b, 2a, and 2b). CONCLUSIONS: Our study confirms that the early response to IFN (loss of HCV RNA at the end of the first week of IFN therapy) can be a predictor of the subsequent sustained response to IFN therapy. Additionally, positivity of HCV RNA at the fourth week of IFN therapy can be a predictor of the subsequent nonsustained response to IFN therapy.

Adolescent↗
PubMed1997

[Long-term clinical results with a new surgical method for the fragile valvular annulus].

We performed prosthetic valve replacement with skirt in 11 patients for the fragile valvular annulus. Subjects included 6 patients with active infective endocarditis involving aortic root abscess, 2 patients with systemic disease requiring steroid treatment, and 3 patients with hemolysis or perivalvular leakage. Operative procedure in 11 patients was performed aortic valve replacement with Dacron or Xenomedica skirt attached to the prosthetic ring. One patient died of heart failure during perioperative period. 2 patients died of arrhythmia, heart failure in late postoperative period. The event free rate was 77.1% since 5 years after operation. We conclude that prosthetic valve replacement with skirt is useful to tha fragile valvular annulus.

Adult↗
PubMed1997

[Development of a blood cardioplegia delivery system for children].

We have developed a blood cardioplegia delivery system for children. Essential points of a delivery system in pediatric cardiac surgery are (1) a small amount of priming volume of a delivery system, and (2) slow, steady infusion of a cardioplegic solution. We changed a heat exchanger to a smaller one for reduction of priming volume, and changed a roller pump tube to a smaller one for slow, steady infusion. Thus, priming volume of a delivery system has reduced from 180 to 100 ml, and we can infuse a cardioplegic solution at a steady rate less than 10 ml/min. Our clinical experience with this system suggests that this blood cardioplegia delivery system is useful for pediatric cardiac surgery.

Blood↗