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Biomedical subjects

S Morikawa

Publications and source records attributed to S Morikawa.

At least 127 records · Page 7Linked to original sources
PubMed1994

Immunomodulatory effects of three macrolides, midecamycin acetate, josamycin, and clarithromycin, on human T-lymphocyte function in vitro.

The effect of three macrolide antibiotics, midecamycin acetate, josamycin, and clarithromycin, on human T-cell function was investigated in vitro. Midecamycin acetate and josamycin suppressed the proliferative response of peripheral blood mononuclear cells stimulated by polyclonal T-cell mitogens at concentrations between 1.6 and 8 micrograms/ml. At higher concentrations (40 to 200 micrograms/ml), all these drugs showed a marked inhibitory effect. At concentrations of 1.6 to 40 micrograms/ml, these drugs suppressed interleukin-2 (IL-2) production induced by mitogen-stimulated T cells, but not the expression of IL-2 receptor (CD25), in a dose-dependent manner. Therefore, the suppressive action on T-lymphocyte proliferation seems to be based on the ability of these drugs to inhibit IL-2 production by T cells. The drug also inhibited mixed lymphocyte reaction at the same concentrations. Combined treatment with these macrolides and the known immunosuppressants such as FK506 and cyclosporin A resulted in an increased inhibition of T-cell proliferation. The immunomodulatory properties of the antibiotics may have clinical relevance for modulation of the immune response in transplant patients and in patients with inflammatory diseases.

Adjuvants, Immunologic↗
PubMed1994

Detection and sequencing of rotavirus VP7 gene from human materials (stools, sera, cerebrospinal fluids, and throat swabs) by reverse transcription and PCR.

Human rotavirus RNAs from stool samples, sera, cerebrospinal fluids, and throat swabs of 15 children with rotavirus gastroenteritis were detected and serotyped by reverse transcription and PCR. The reverse transcription-PCR method may allow us to consider rotavirus infections in other parts of the body in addition to the gastrointestinal tract. Moreover, sequence analysis of the VP7 gene was performed on seven samples (one stool, two serum, three cerebrospinal fluid, and 1 throat swab sample). There were no appreciable differences in viral sequences between samples from cerebrospinal fluids, sera, or stools.

Acute Disease↗
PubMed1994

Detection of myocardial ischemia by 31P magnetic resonance spectroscopy during handgrip exercise.

BACKGROUND: The metabolic changes of myocardial ischemia in patients with coronary artery disease assessed by 31P magnetic resonance spectroscopy (MRS) have been reported previously. A significant decrease in the ratio of phosphocreatine (PCr) to ATP during handgrip exercise in a group of patients with severe coronary artery disease has been demonstrated. However, there are no reports at present that directly compare cardiac 31P MRS data with exercise 201Tl myocardial scintigraphy, now established as one of the most important clinical methods to assess myocardial ischemia. The purpose of this study was to investigate whether 31P MRS with handgrip exercise testing is able to detect myocardial ischemia, demonstrated by exercise 201Tl scintigraphy. METHODS AND RESULTS: Twenty-seven patients with severe stenosis of the left anterior descending coronary artery (> or = 75%) and 11 normal control subjects composed the present study. Patients were divided into two groups on the basis of exercise 201Tl scintigraphy: a reversible 201Tl defect group (RD[+]) who demonstrated redistribution at the late image and a fixed 201Tl defect group (RD[-]). While lying supine within the magnet, subjects performed handgrip exercise at 30% of maximal force once in every two cardiac cycles. 31P MR spectra were collected before and during handgrip exercise. Data were corrected for the saturation factor. ANOVA revealed significant differences among the three groups with respect to the mean +/- SD PCr/ATP ratio at rest (control, 1.85 +/- 0.28 > RD(+), 1.60 +/- 0.19 > RD(-), 1.24 +/- 0.30; P < .05). The PCr/ATP ratio decreased significantly from 1.60 +/- 0.19 at rest to 0.96 +/- 0.28 during exercise (P < .001) in the RD(+) group (n = 15). However, in the RD(-) group (n = 12), the ratio did not change significantly during handgrip exercise (1.24 +/- 0.30 at rest versus 1.19 +/- 0.28 during exercise). Similarly, the ratio did not change in the control group (n = 11) (1.85 +/- 0.28 at rest versus 1.90 +/- 0.23 during exercise). CONCLUSIONS: Contrary to normal subjects or patients with fixed thallium defects, the PCr/ATP ratio was significantly altered by exercise in patients with reversible thallium defects. These results suggest that 31P MRS with handgrip exercise testing is a sensitive method for detecting myocardial ischemia.

Adenosine Triphosphate↗
PubMed1994

[Development of a troublesome behavior scale (TBS) for elderly patients with dementia].

A rating scale for assessing troublesome behavior associated with dementia illnesses was developed. This instrument, named the troublesome behavior scale (TBS), is designed to be completed by family and professional caregivers. It is comprised of 14 questions assessing a variety of types of disruptive or burdensome behavior. Two of the 14 questions differ in their assessment for outpatients and that for inpatients. Each of the 14 items is rated with 5 possible responses corresponding to the frequency of the behavior in the preceding month (from 0 = never, to 4 = once every day or more). Thus, higher scores indicate more disturbance. The TBS was administered to 146 outpatients and 167 inpatients with dementia based on the DSM III-R criteria in order to test its reliability and validity. The data were analyzed separately for outpatients and inpatients. The reliability of the scale, based on calculation of perfect agreement rates and kappa values, indicated high test-retest and inter-rater reliability for both samples. Validity, by confirmatory factor analysis of the data from the outpatients, revealed three main factors, namely, "behavior toward caregivers", "self-absorbed behavior" and "elaborate behavior". The same analysis of data from inpatients resulted in a different set of three factors: "behavior interfering with care work", "behavior necessitating watchful protection" and "behavior resulting in missing articles". From these findings TBS appears to be a reliable and valid instrument for assessing troublesome behavior of patients with dementia.

Aged↗
PubMed1994

[Evaluation of the effects of vibro-acoustic stimulation test on the fetus during labor under epidural analgesia and evidence of its safety by way of auditory brainstem response].

This study was undertaken to elucidate the effects of epidural analgesia on vibro-acoustic stimulation test (VAST) during normal labor and auditory brainstem response (ABR) in fifty full term parturients without any complication. The safety of VAST in relation to the ABR of neonates was also studied. The results were as follows, 1) There were some changes in CTG monitoring in five cases (10%) in the 10 minutes after epidural analgesia. However, these changes were not ominous signs but all related to the coiling of the cord, as previously reported. 2) The ABR latency-intensity curve (audio-function of the newborn infants) revealed no hazardous change in VAST-loaded infants or in the controls. The response threshold was 10dB in this study. The application of VAST to the parturients under epidural analgesia was therefore not only harmless to the fetuses but also a useful way to evaluate fetal well-being.

Acoustic Stimulation↗
PubMed1994

[Development of an assessment of basic care for the demented (ABCD)].

A rating scale measuring care status related to assistance with basic ADL for demented patients was developed. This instrument, named the ABCD, is designed to be completed by family and professional caregivers, and consists of two subscales assessing the level of difficulty of help with the ADL (difficulty scale) and the reasons why assistance is needed (reason category). In the difficulty scale, each of 6 items is rated with 4 possible responses corresponding to the degree of physical assistance from the caregiver and of the patient's cooperation with the assistance. In the reason category, for 5 activities excluding voiding, the reason is assessed with the following three possible responses: A; physical disability, B; disability in motivation and/or so-called apraxia, C; a combination of A and B. The ABCD was administered to 124 outpatients and 203 inpatients with dementia based on the DSM III-R criteria in order to test its reliability and validity. The data from the out- and inpatient samples were analyzed separately. The reliability study of the two subscales based on calculation of perfect agreement rates and kappa values indicated high test-retest and inter-rater reliability for both samples. The Cronbach alpha values of the difficulty scale were also high. As to the validity of the difficulty scale, there was a significantly high correlation between the score obtained with this scale and the results of two established assessment instruments. For the outpatients, logistic regression analysis revealed that the score obtained with this scale was the only predictor of institutionalization and mortality within 1 year after the baseline examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1993

The three-dimensional structure of the colicin E3 immunity protein by distance geometry calculation.

The three-dimensional solution structure of the colicin E3 immunity protein (84 residues) was determined by distance geometry calculations. The hydrophilic side of a four-stranded antiparallel beta-sheet constitutes a part of the surface of the protein, and two loops lie on the hydrophobic side of the sheet. All the three specificity-determining residues, which are included in the center of the beta-sheet, display their side groups on the protein surface.

Amino Acid Sequence↗
PubMed1993

1H-detected in vivo 13C NMR spectroscopy and imaging at 2T magnetic field: efficient monitoring of 13C-labeled metabolites in the rat brain derived from 1-13C-glucose.

Gradient-select hetero-nuclear multiple quantum coherence in nuclear magnetic resonance (NMR) an indirect method of detecting nuclei in low sensitivity by 1H NMR, was used to observe 13C-enriched metabolites in the rat brain in vivo, with a 2 T NMR system. We detected the accumulation of 13C-labeled glucose and its metabolites, glutamine and/or glutamate, in less than 5 min. The extension of this technique to chemical shift imaging permitted the localization of these chemicals in the rat brain. This approach may have various applications for non-invasive monitoring of 13C-labeled compounds in humans and other animals.

Animals↗
PubMed1993

Recombinant human IL-5 augments immunoglobulin generation by human B lymphocytes in the presence of IL-2.

The biological activity of interleukin-5 (IL-5) on human B lymphocytes was examined by using a newly purified recombinant human IL-5 preparation. Different densities of B cells from human tonsil samples were isolated by Percoll density gradient from nonrosetted cells. The IL-5 preparation did not act as a B cell growth factor on the large (in vivo-activated) or small (resting) B cells after activation with polyclonal B cell activators. The IL-5 augmented the immunoglobulin (Ig) generation of Staphylococcus aureus Cowan strain I (SAC)-activated B blasts in the presence of interleukin-2 (IL-2). The effect of IL-5 on Ig generation was greater in pokeweed mitogen (PWM)-driven B blasts than that in SAC-induced B blasts when assessed by enzyme-linked immunosorbent assay. The amounts of mu RNA isolated from IL-5/PWM-treated cells were also larger than those from IL-5/IL-2-treated B blasts. These results suggest that the human IL-5 can increase Ig generation of B cells in the presence of IL-2 by working at the level of mRNA coding for Ig.

B-Lymphocytes↗
PubMed1993

Energy metabolism of the heart and the liver in brain-dead dogs as assessed by 31P NMR spectroscopy.

The energy metabolism of the heart and the liver was assessed in brain-dead dogs by 31P nuclear magnetic resonance spectroscopy. The mean blood pressure and pulse rate changed respectively from 136.1 +/- 9.3 mm Hg (mean +/- SEM) and 126.7 +/- 4.4/min in the control period, to 212.9 +/- 15.8 mm Hg and 146.7 +/- 13.3/min during Cushing phenomenon (CU period), and to 60.0 +/- 6.4 mm Hg and 60.0 +/- 2.9/min after completion of brain death (BD period). The ratio of creatine phosphate to inorganic phosphate (PCr/Pi) of the heart decreased from 5.00 +/- 1.08 to 3.24 +/- 0.80 in the CU period and increased to the levels of the control values in the early BD period. The intracellular pH of the heart decreased from 7.20 +/- 0.07 to 6.91 +/- 0.02 in the CU period and increased to 7.12 +/- 0.01 in the BD period. The positive relationship between the Pi/PCr and the rate-pressure product (BP x PR) indicates that the regulation of the oxidative metabolism by free ADP was well maintained except at some points in the CU period (Pi/PCr = 8.77 x 10(-6) BP x PR + 0.164, r = 0.704). This suggested that the remarkable hypotension and bradycardia in the BD period is not associated with cardiac energy failure. Although the energy states of both the heart and the liver in brain-dead dogs were adequately maintained in the BD period, the changes were different.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1993

Characterization of vaccinia surface antigen expressed by recombinant baculovirus.

The gene encoding the vaccinia surface antigen (S antigen) was inserted into a baculovirus transfer vector and a recombinant virus was isolated. The S antigen was expressed on the surface of Spodoptera frugiperda cells (Sf cells) infected with the recombinant baculovirus. Recombinant proteins were detected in immunoblotting with anti-vaccinia serum and have the apparent molecular weight of 40 and 50-kDa. The 50-kDa polypeptide was tunicamycin sensitive and was thus glycosylated. The glycosylated 50-kDa polypeptide was also secreted into culture supernatants. Antiserum directed against the expressed S antigen specifically reacted to the authentic S antigen that is located on the mammalian cells infected with vaccinia virus, but did not affect the production of infectious progeny virus. Antisera against both the terminal regions of the S antigen were prepared by immunizing rabbits with the recombinant fusion proteins produced in the bacterial expression vector. The S antigen on the cell surface reacted by immunofluorescence with anti-C-terminus serum but not or very weakly with anti N-terminus serum, indicating that the hydrophobic N-terminus functions both as a signal and a membrane anchor sequence. Interleukin (IL)-1 alpha failed to bind to the S antigen expressed on insect and mammalian cells, although the homology between IL-1 receptor and the S antigen has been reported by computer analysis of amino acid sequence.

3T3 Cells↗
PubMed1993

Genetic variation in VP7 gene of human rotavirus serotype 1 (G1 type) isolated in Japan and China.

Sequence analysis of the gene encoding the major neutralization glycoprotein (VP7) was performed on 12 human isolates of serotype 1 of rotavirus in Japan and China. They were examined for genetic variations among serotype 1 isolates. Comparative studies of their nucleotide and deduced amino acid sequences between the 12 isolates and the Wa strain revealed an overall homology of more than 92 and 96%, respectively. Higher degrees of homologies were observed between Wa and 2 strains (K1 and K2) in Tokyo, 1979-1980, than between Wa and recent isolated strains in Tokyo and in China. In our isolates, a total of 16 amino acid residues frequently converted to another amino acid. Six amino acid residues belonging to the major neutralizing epitope regions (B, D, and E in this communication) frequently converted. From these data three subtypes (subtypes A, B, and intermediate) were suggested to be divided. Whether these differences are an important mechanism in the epidemiology of rotaviruses requires further investigation.

Amino Acid Sequence↗
PubMed1993

Deuterium chemical shift imaging for the estimation of cerebral perfusion in rabbit infarction model.

In order to develop a new technique for the measurement of local cerebral blood flow (CBF), the deuterium chemical shift imaging (2H-CSI) technique, an application of in vivo nuclear magnetic resonance (NMR), was used for the estimation of cerebral perfusion in rabbit infarction model. The 2H chemical shift images of rabbit brain were obtained every 30 seconds before and after intravenous injection of deuterated saline. The changes in 2H NMR signal intensity documented that the cerebral perfusion in the damaged area due to infarction decreased obviously compared to that in the intact area. These findings indicate that the 2H-CSI technique can be applied to the measurement of local CBF. The readily availability and limited toxicity of deuterated water may make possible to use this method in clinical cases.

Journal Article↗
PubMed1993

Proton magnetic resonance spectroscopy with dementia.

To provide new insights into metabolic changes in the brain of patients with dementia, we performed in vivo localized proton magnetic resonance spectroscopy in nine patients with primary degenerative dementia and in three patients with normal-pressure hydrocephalus. We compared the results with those in 26 healthy volunteers. Measurements of regional cerebral blood flow were performed in seven patients by means of single photon emission computed tomography with amphetamine I 123 as a tracer. The magnetic resonance spectra constantly showed three major peaks corresponding to N-acetylaspartate (NAA), creatine and phosphocreatine (Cr), and choline-containing compounds. There were no age-related changes in the mean area ratio of NAA to Cr in neurologically normal volunteers. The NAA/Cr ratio was significantly reduced in patients with primary degenerative dementia. The reduction of the NAA/Cr ratio was observed even in dementia patients with no significant brain atrophy or reduction in regional cerebral blood flow. No significant reduction of the NAA/Cr ratio was seen in patients with normal-pressure hydrocephalus. The NAA/Cr ratio might reflect the number and/or activity of neuronal cells in the brain. Proton magnetic resonance spectroscopy may well provide a useful tool for early detection of, and further pathophysiological study of, primary degenerative dementia.

Adult↗
PubMed1993

Detection of Epstein-Barr virus transcripts in chemically or immunologically-activated cells and in a null cell-line (HLN-STL-C) by in situ hybridization with alkaline phosphatase-linked oligonucleotide probes.

We report a simple procedure for the detection of Epstein-Barr virus (EBV) by in situ DNA-RNA hybridization with an alkaline phosphatase-linked oligonucleotide probe. EBV-producing cell lines P3HR-1 and Akata were treated with phorbol ester and n-butyrate, and anti-human IgG, respectively. This treatment resulted in highly increased populations of cells with EBV transcripts of the latent membrane protein 1 (LMP1) and envelop glycoprotein gp350/220, but not of EBV-encoded small nuclear RNAs (EBERs). Synthesis of the LMP1 protein, which was encoded by the induced mRNA, was mostly dependent on viral DNA synthesis, as shown by double or single labeling for in situ DNA-DNA hybridization with the oligo-nucleotide probe, and immunoperoxidase staining with a monoclonal antibody against LMP1. In situ hybridization of the null cell line HLN-STL-C established from an adult T-cell leukemia patient showed that 100% of the cells contained both EBERs and LMP1 mRNA and about 0.1% of the cells contained gp350/220 mRNA, indicating that a few of the null cells which carried the EBV genome spontaneously entered the late EBV replication cycle.

Animals↗