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S Morikawa

Publications and source records attributed to S Morikawa.

At least 19 recordsLinked to original sources
PubMed1992

Chemical assessment of phospholipid and phosphoenergetic metabolites in regenerating rat liver measured by in vivo and in vitro 31P-NMR.

For the assessment of 31P-NMR spectroscopic data, phospholipid precursors (phosphorylethanolamine (PE) and phosphocholine) and catabolites (glycerophosphorylethanolamine (GPE) and glycerophosphorylcholine (GPC)), as well as adenosine phosphates were chemically determined in regenerating rat liver. The data were compared with those obtained by in vivo and in vitro 31P-NMR spectroscopies. Chemical assay revealed a significant increase of PE and a decrease of GPE, GPC and ATP in hepatectomy group compared to sham operation group. The values obtained by in vitro NMR were in good agreements with those of chemical assay, but significant differences between the two groups were observed only in PE and inorganic phosphate (Pi). Noticeable increase in PME was not detected by in vivo 31P-NMR spectroscopy, although the increase of PE was about 2.5-times that of the control and its constitution ratio to the whole phosphomonoester (PME) was less than 15%. On the other hand, in vivo NMR showed a large phosphodiester (PDE) peak occupying approx. 40% of the total phosphorus signal, while the contribution of its constituents, GPE and GPC was about 5% found by both chemical assay and in vitro NMR. The PDE peak in in vivo NMR seemed to reflect the membrane phospholipid itself rather than its catabolites. A slight decrease of phosphoenergetic level in regenerating rat-liver was commonly suggested by all three analytical methods.

Animals↗
PubMed1992

The synthesis of cadystins, heavy metal chelating peptides, is induced in the fission yeast by wounds of the cell wall or by incubation with chitosan.

It has been shown that heavy metal administration induced the synthesis of cadystins, the small metal chelating peptide with the general structure of (gamma-glu-cys)n-gly, in the fission yeast and in plants. Besides heavy metals, wounds to the cell surface or the incubation with chitosan induced the cadystin synthesis in the fission yeast. Under these induction conditions, the membrane permeability of the fission yeast significantly increased suggesting the structural alteration of the membrane. In these induction, the synthesized cadystins formed complexes with the cellular zinc ions together with or without glutathione.

Amino Acid Sequence↗
PubMed1992

Identification and analysis of the gag-pol ribosomal frameshift site of feline immunodeficiency virus.

The pol genes of retroviruses are translated as gag-pol fusion proteins by ribosomal frameshifting within the gag-pol overlap region. During the ribosomal frameshift event, the gag open reading frame is shifted -1 nt to allow in-phase reading of the pol open reading frame. A consensus frameshift signal sequence of GGGAAAC within the gag-pol overlap region of feline immunodeficiency virus (FIV) has been identified followed by a sequence that has the potential for a pseudoknot tertiary structure. Using recombinant baculoviruses in which the frameshift occurs efficiently, the consensus sequence has been shown to be the site of the frameshift event. A mutation creating a termination codon just downstream of the putative frameshift signal sequence but upstream of the potential pseudoknot structure made a shorter gag product, but did not affect the efficiency of frameshifting. A mutation creating a termination codon just upstream of the putative frameshift signal made a shorter product and essentially abrogated frameshifting. Mutations in the first stem or the second stem in the potential pseudoknot structure severely reduced the frameshifting efficiency. Mutations which altered the length between the frameshift signal and the pseudoknot structure (the so-called spacer region) also reduced the frameshift efficiency. The insertion of a palindromic sequence, which could form a hairpin structure just upstream of the frameshift signal sequence, also affected the frameshifting. These results support the view that the ribosomal frameshift event in the FIV gag-pol region involves the identified signal sequence and appears to require the precisely positioned downstream sequence and indicated pseudoknot structure for efficient frameshifting.

Animals↗
PubMed1992

Analysis of a human immunodeficiency virus type 1 isolate carrying a truncated transmembrane glycoprotein.

We have recently reported the isolation of a human immunodeficiency virus type 1 (HIV-1), KB-1gp32 carrying a shorter size (32 kDa) of transmembrane glycoprotein (TMP) from TALL-1 cells persistently infected with KB-1gp41 virus strain (Shimizu et al., 1990a). Endoglycosidase treatments showed that the different size of the TMP between the two strains was due to a truncation of 9 kDa of polypeptide in the KB-1gp32 TMP coding region. Sequence analysis revealed the substitution of a CAG codon to a TAG stop codon just downstream of the putative membrane-spanning domain of the TMP of KB-1gp32. This resulted in a truncation of some 133 amino acids of the cytoplasmic domain of TMP. The data indicate that a premature stop codon in KB-1gp32 has been introduced during adaption of the parental virus to TALL-1 cells. We have constructed two chimeric clones between the env region of a clone pKB-1, derived from KB-1gp32, and an infectious molecular clone pNL-432. We have also constructed a site-directed mutant of pNL-432 carrying a premature stop codon at the same position as the env stop codon of pKB-1. Among the three clones carrying a premature stop codon in env, only one chimeric clone was infectious to TALL-1 but not MT-2 cells. This clone contained the entire tat, rev, vpu, and env genes of pKB-1. The pNL-432 mutant was not infectious. The results suggest that some sequences of pKB-1 might compensate for the truncation of the TMP during replication in TALL-1 cells.

Amino Acid Sequence↗
PubMed1992

Inhibition of proliferation and differentiation of human B-lymphocytes by a biscoclaurine alkaloid.

A biscoclaurine alkaloid, cepharanthine, is known to be a potent inhibitor of snake venom-induced hemolysis by interaction with the lipid bilayer of the membrane. The drug also interferes with the ion channel intracellularly. In this study, we examined the effect of cepharanthine on human B-cell functions. Small dense B-cells from tonsil samples were isolated using a Percoll density gradient from non-rosetted cells and were used as the target cells. Cepharanthine inhibited the proliferation of the lymphocytes and antibody production of human B-lymphocytes. The inhibitory effect of cepharanthine on the proliferation was caused by the arrest of the late G1 to S phase transition in the cell cycle. However, the mechanism of suppression of antibody formation remains unknown. These results suggest that cepharanthine acts on human B-cells as an immunomodulating agent.

Adjuvants, Immunologic↗
PubMed1992

Major core proteins, p24s, of human, simian, and feline immunodeficiency viruses are partly expressed on the surface of the virus-infected cells.

We have previously shown the expression of human immunodeficiency virus type 1 (HIV-1) major gag protein, p24, on the surface of persistently HIV-1-infected cells by using murine monoclonal antibodies (mAb). We now report that the cell surface gag p24 antigen expression is a universal phenomenon among HIV-1, simian immunodeficiency virus (SIV), and feline immunodeficiency virus (FIV). The mAbs prepared by immunization with purified HIV-1 particles were used as antibodies cross-reactive to HIV-1 and SIVagmp24 antigens. The mAbs to FIV p24 were raised against the gag precursor 50 kDa protein of FIV, which was expressed by Baculovirus vector. The p24 antigen expression on the cell surface was detectable in certain combinations of virus-host cell systems in all of these viruses. Since these p24 regions of the animal viruses seem to play as important a role in cell-mediated immunity as that of HIV-1, the p24 applicability as a candidate epitope for vaccine development could be evaluated in those animals.

Animals↗
PubMed1992

Long-term follow-up of vascularized bone grafts for the reconstruction of tibial nonunion: evaluation with computed tomographic scanning.

Ten cases of reconstruction of the tibia with vascularized bone grafts were evaluated by computed tomographic (CT) scanning. In all cases the grafts were placed because of pseudarthrosis. The patients ranged in age from 20 to 64 years. The duration of follow-up was 1-9 years. In six cases fibular grafts were used to bridge the defect and in four cases iliac crest grafts were used. No additional bone grafts were placed after the initial operation. The pseudarthroses were classified into three types: type N--no bony defect (4 cases); type P--partial bony defect (3 cases); and type C--complete segmental bone loss (3 cases). Our evaluation showed that the grafts used to treat the type N and type P pseudarthroses were the same shape and size as at the time of placement. The grafts used to treat the type C pseudarthroses were hypertrophied, although the medullary canal of the graft remained the same size as at the time of placement. Hypertrophy was a result of an extraperiosteal reaction. The fibular grafts were square rather than triangular in cross section. It was concluded that mechanical loading is important in promoting hypertrophy of the graft.

Adult↗
PubMed1992

The suppressive effect of deoxyspergualin on the differentiation of human B lymphocytes maturing into immunoglobulin-producing cells.

Deoxyspergualin, an analog of spergualin, has been known as a novel immunosuppressive agent with strong immunosuppressive activity in in vivo experimental systems. In the present study, we examined the effect of deoxyspergualin (DSG) and methyldeoxyspergualin (MeDSG) on the proliferation and differentiation of human B lymphocytes in vitro. Highly purified B cells from human tonsil samples were isolated by Percoll density gradient from nonrosetted cells and were used as target cells. Both agents had little effect on the proliferative response of resting or activated B lymphocytes. However, they suppressed the immunoglobulin synthesis of B lymphocytes not only in a T cell-dependent, but also in a T cell-independent system. The inhibition of antibody synthesis was manifested in the early stage of B cell differentiation. Both drugs also suppressed Ig secretion, but not proliferation, of an EBV-transformed human B lymphoblastoid cell line. These results indicate that DSG and MeDSG have a selective immunosuppressive effect on the differentiation pathway of B lymphocytes.

Antibody-Producing Cells↗
PubMed1992

The distinct effects of FK506 on the activation, proliferation, and differentiation of human B lymphocytes.

We examined the effect of FK506 on the activation, proliferation and differentiation of human B lymphocytes in vitro. FK506 inhibited the proliferative response of resting B cells induced by Staphylococcus aureus Cowan strain I (SAC) and phorbol myristate acetate (PMA) in a dose-dependent manner. Inhibition of cell proliferation by FK506 was caused by a selective block of G0 to G1 phase transition leading to cell arrest. In addition, the proliferative response of in vivo-activated B cells and lymphokine-driven B cell proliferation were also found to be sensitive to FK506. Interestingly, FK506 did not affect the expression of activation antigens such as CD23, IL-2 receptor (CD25), and transferrin receptor (CD71). Finally, FK506 had little effect on B cell antibody generation in a T cell-independent system. Conversely, FK506 suppressed neither proliferation nor immunoglobulin secretion in a human B lymphoblastoid cell line. These results indicate that FK506 has discrete effects on the different stages of the B cell maturation.

Antibody-Producing Cells↗
PubMed1992

Degradation of streptomyces metalloprotease inhibitor (SMPI) by neutral protease from Bacillus subtilis var. amylosacchariticus.

The zinc-containing neutral endopeptidase (neutral protease: BANP) from Bacillus subtilis var. amylosacchariticus was inhibited by the proteinaceous metalloprotease inhibitor isolated from Streptomyces nigrescens (SMPI). The degree of inhibition was, however, significantly less than that for thermolysin (TLN). During incubation of BANP with SMPI, the inhibitor was proteolytically degraded and inactivated. Analysis of the digestion products suggested that a minor diversity in their substrate specificities between TLN and BANP affects the sensitivity to the proteinaceous metalloprotease inhibitor, SMPI.

Amino Acid Sequence↗
PubMed1992

Incidence of feline immunodeficiency virus reactive antibodies in free-ranging lions of the Kruger National Park and the Etosha National Park in southern Africa detected by recombinant FIV p24 antigen.

Lion sera from the Kruger National Park (KNP) dating back to 1977 and from the Etosha National Park (ENP), obtained from 1989 to 1991, have been analysed by ELISA and Western blot analyses using a genetically engineered antigen representing the p24 structural protein of feline immunodeficiency virus (FIV). It was concluded that some 83% of 98 KNP lion sera reacted with the p24 antigen, while none of 28 ENP lion sera reacted. A few other KNP felids (cheetahs and genets) gave samples that did not react with the FIV p24 antigen. For the KNP lions, apart from a lower prevalence in cubs (50%), no particular trends were demonstrated in terms of age, sex, date or origins of the samples. In Western blot and radio-immunoprecipitation analyses the lion sera reacted with the engineered p24 antigen, as well as with the p15 and p24 gag proteins and the p50 gag precursor protein from FIV, indicating that the agent is probably a lentivirus related to FIV. The ELISA with the engineered p24 antigen required less serum and appears to be more sensitive at detecting FIV-reactive antibodies than assays with available commercial kits.

Africa, Southern↗
PubMed1992

[Development of an experimental model for spontaneous lymph node metastasis of human esophageal carcinoma in nude mice--histopathological analysis].

Three human squamous cell carcinoma cell lines (HPL-EsC-1-K, -S, and -M) originated from a male patient with esophageal carcinoma were established and were studied on their tumorigenic and metastatic properties in nude mice. All cell lines grew in the hind foot pads following subcutaneous inoculation and produced popliteal lymph node metastasis dose (2-8 x 10(6)/mouse)-dependently. Based on the histopathological findings on serial sections of the lymph nodes, the stages of lymph node invasion by cancer cells were classified into 4 stages (St. 0-III). The time course of lymph node metastasis of EsC-K cells were examined. Advanced stage of metastasis increased according to the time elapsed after tumor cell inoculation. Incidence of metastasis of EsC-K cells were not affected by host factors such as sex differences, anti-asialo GM1 antibody treatment on the hosts. Today, there are few experimental models for studies on spontaneous lymph node metastasis of human carcinomas. This experimental model provides a useful research tool for studies on the biology and therapy for lymph node metastasis of esophageal cancer.

Animals↗
PubMed1992

[A case of severe juvenile pulmonary tuberculosis associated with malnutrition in special reference to nutritional assessment].

We reported a case who had suffered from severe pulmonary tuberculosis in association with severe malnutrition. A 19-year-old man was admitted complaining of high fever, productive cough and body weight loss. Before admission, he worked as a cook for long hours a day and had meals irregularly. On admission, he was cachexic. Coarse crackles were auscultated on the both lung field, and the liver was enlarged. Chest X-ray revealed multiple ringed and mottled shadows mainly in bilateral upper and middle lung field. Laboratory examination revealed inflammatory reaction defined by an increase of white blood cells, accelerated erythrocyte sedimentation rate and positive CRP, impairment of liver function and cell-mediated immunity, hypoxemia and restrictive lung dysfunction. Ziehl-Neelsen stain of sputum showed a large number of acid fast bacilli. The assessment of his nutritional status showed decrease in anthropometric measurements, visceral proteins and the Fischer ratio, which suggested that he was in the status of protein-calorie malnutrition in association with amino acid imbalance. He was treated with nutritional therapy in addition to antituberculous drugs, which improved his clinical symptoms, laboratory data and nutritional assessment. These results suggested the importance of nutritional assessment and nutritional therapy based on it.

Adult↗
PubMed1992

[A prospective study of psychosomatic reaction to hysterectomy].

Psychosomatic reaction to hysterectomy was prospectively studied by means of psychological tests and a questionnaire. One hundred and twenty patients who had simple hysterectomy were examined before and as long as one year after operation. The mean score for A-state, a state anxiety scale, was high before operation and rapidly declined postoperatively. SRQ-D and CMI, which represent depressive and neurotic states, respectively, showed rather high scores before and 2 weeks after operation. Mean scores in these psychological tests declined to a plateau within 6 months after operation, and there were less psychological and physiological symptoms and there was improved physical activity, showing that most patients can over come psychosomatic problems caused by hysterectomy. A close correlation was observed between the results of psychological tests and the number of psychological symptoms. Forty patients with a high SRQ-D score showed abnormality in other scales. Psychosomatic disorders associated with hysterectomy are characterized by various symptoms but mainly by a depressive state. High SRQ-D patients were divided into three subgroups: A) the SRQ-D score is constantly high, B) the SRQ-D is high for the first several weeks, and C) the score increased after discharge. Patients in each subgroup showed signs of a characteristic personality. These results show the presence of a different psychosomatic approach to the patients personally.

Anxiety↗
PubMed1992

[The study on intravesical instillation of THP in the treatment of in-situ and superficial bladder cancers].

The efficacy and safety of Pirarubicin (THP), administered by intravesical instillation, have been studied in recurrent multiple superficial bladder cancer patients and patients who tested positive by urine cytology but lacked protuberant legions (CIS). The average age and range of the 19 patients (M 15, F4) studied were 63.3 (37-84). Twelve patients had protuberant, multiple cancer and 7 patients had CIS. Sixteen of the cases were recurrent disease. Twenty mg THP, delufed in 40 ml of 5% glucose solution were instilled for 2 hours once or twice a week. Each patients received 8 treatments. One week after the last treatment, the therapeutic result was evaluated on the bases of cystoscopy and urine cytology. Before and after administration, CBC and biochemical blood tests were run. Nine of the 12 patients (75%) with multiple recurrent tumor and all the 7 patients with CIS showed complete response. The total outcome for CR was 84.2% in this study. Intravesical instillation with THP did not cause any serious side effects.

Administration, Intravesical↗
PubMed1991

In vivo oxygen-17 nuclear magnetic resonance for the estimation of cerebral blood flow and oxygen consumption.

To explore the feasibility of in vivo 17O NMR for the estimation of cerebral blood flow and oxygen consumption, in vivo 17O NMR spectroscopy and imaging were employed in animal models. In the spectroscopy, the changes in the 17O NMR signal intensity after the injection of H2(17)O and the inhalation of 17O2 gas were obtained every 4 seconds with sufficient signal-to-noise ratios for the quantification of cerebral blood flow and oxygen consumption. In the imaging, although the time and spatial resolutions were insufficient for the quantification of H2(17)O, 17O NMR images of rabbit brain could be obtained, indicating that it is possible to map cerebral blood flow and oxygen consumption by 17O NMR imaging.

Animals↗
PubMed1991

Effect of 17 beta-estradiol on the growth of an estrogen receptor-positive human esophageal carcinoma cell line.

Receptors for estrogen and for androgen in the nucleus and cytosol (ERn, ERc, ARn, and ARc, respectively) were studied on two newly established human esophageal carcinoma cell lines, ES-25C and ES-8C. ES-25C was ERn+ (the binding content 4.0 fmol/mg protein, Kd 0.09 nM), ERc-, ARn-, and ARc-. No receptors were found in ES-8C. Various doses of 17 beta-estradiol (E2) were added in vitro to investigate its effect on the growth of these cell lines. No effect of E2 was observed on ER--ES-8C cell line. The growth of ES-25C cell was significantly inhibited at the doses of 10(-10) and 10(-12) mol/l E2 compared with the control. The doubling time of 10(-12) mol/l E2-treated cells was 32 hours whereas that of control was 20 hours. This slower growth was reflected in the deduction of cells in S-phase utilizing 5-bromo 2'-deoxyuridine (BrdU) labeling. The current results strongly suggest that the growth inhibition of ER+ esophageal cancer cell by E2 is mediated by signal transduction induced by the estrogen-estrogen receptor system.

Aged↗