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Biomedical subjects

S Oda

Publications and source records attributed to S Oda.

At least 415 records · Page 23Linked to original sources
PubMed1987

Effect of immunosuppressive factors produced by adult T cell leukemia cells on B cell responses.

The immunosuppressive activity of sera from adult T cell leukemia (ATL) patients and culture supernatants of ATL cells and ATL cell lines on B cell responses was examined in vitro. ATL sera and culture supernatants of ATL cells suppressed B cell proliferative and differentiative responses induced with B cell mitogens such as Staphylococcus aureus Cowan I and pokeweed mitogen. The suppressive effect was observed not only in the production of B cell growth factors (BCGF) and B cell differentiation factors (BCDF) by T cells, but also in the responsiveness of B cells to BCGF and BCDF. These results suggest that the immunosuppressive factors produced by ATL cells might act to suppress both the cellular immunity and the humoral immunity, and could have an important role in the induction of immunodeficient states in ATL patients.

B-Lymphocytes↗
PubMed1987

[The antimicrobial activity of sisomicin against fresh clinical isolates].

Antimicrobial activities of sisomicin (SISO) against clinical isolates obtained in the second half of 1986 were investigated together with other 4 aminoglycosides (AGs) (gentamicin (GM), tobramycin (TOB), dibekacin (DKB), amikacin (AMK] and 2 cephems (cefotiam, cefotaxime), and were compared to the results reported in the period of late 1970's through early 1980's in Japan. 1. The incidence of SISO-resistant Staphylococcus aureus in the present study was 18% and is comparable to that of the other studies suggesting that the incidence of SISO resistant strains remains on the stable level. The incidence of SISO-resistant Pseudomonas aeruginosa showed the tendency of slight increase. 2. SISO-resistant strains of Enterobacter spp., Serratia marcescens and Citrobacter freundii did not show increase from the 1970/1980 levels. 3. Isolation rates of SISO-resistant indole(+) Proteus varied depending on strains. Isolation rates of SISO-resistant P. vulgaris and Morganella morganii were both as low as 4%, but that of Providencia rettgeri was as high as 60%. Refering to an American study reporting that the Genus Providencia including P. rettgeri showed high incidence of resistance to SISO as well as to GM or TOB, we pointed out that the antimicrobial activity of AGs against Genus Providencia should be evaluated separately from those of other indole(+) Proteus strains. 4. No SISO-resistant strains of Escherichia coli, Klebsiella pneumoniae or P. mirabilis were found. 5. SISO had good antimicrobial activity against most of the investigated species and SISO may still be regarded as one of the clinically useful AGs.

Bacterial Infections↗
PubMed1987

[Antimicrobial activity of sulbactam/cefoperazone. Comparison with other new cephems].

Antimicrobial activities of sulbactam/cefoperazone (SBT/CPZ) against 50 fresh clinical isolates of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter spp., Serratia marcescens, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were compared to those of CPZ, Cefotiam (CTM), Cefotaxime (CTX) and Latamoxef (LMOX). Minimal inhibitory concentrations (MIC's) of SBT and CPZ mixed in a ratio of 1:1 were determined by the dilution method using Mueller-Hinton agar and expressed by absolute concentrations of CPZ. Antimicrobial activities of SBT/CPZ against principally penicillinase (PCase) producing bacteria, i.e., S. aureus, E. coli, K. pneumoniae, P. mirabilis, were superior to those of CPZ alone. The presence of SBT in concentrations around 0.39 approximately 1.56 micrograms/ml clearly enhanced CPZ's antimicrobial activities against these PCase producing strains. The synergistic antimicrobial effects of SBT in combination with CPZ were less pronounced against principally cephalosporinase (CEPase) producing bacteria, i.e., C. freundii, Enterobacter spp., S. marcescens, P. vulgaris, and P. aeruginosa, and exerted with SBT at concentrations around 3.13 approximately 12.5 micrograms/ml. Comparative antimicrobial activities indicated by MIC80's of tested agents showed that SBT/CPZ had more stable activities against bacteria ranging from Gram-positive to Gram-negative bacteria than CTM, CTX and LMOX. MIC's of SBT/CPZ were higher than 25 micrograms/ml against 8% of S. aureus, 18% of C. freundii, 10% of Enterobacter spp., 26% of S. marcescens, 2% of P. vulgaris, and 18% of P. aeruginosa. These resistant strains against which the addition of SBT showed no synergism, may possess other mechanism of resistance than beta-lactamase production. It is concluded that the presence of CPZ resistant strains is an actual current problem and not an imaginary future problem, and that the number of resistant strains against other new cephems which have different chemical structure from CPZ is increasing. When these present bacteriological environments are considered, the appearance of SBT/CPZ in the clinical practice is timely and meaningful.

Bacteria↗
PubMed1987

[Antibacterial activities of various aminoglycosides against clinically isolated methicillin-resistant Staphylococcus aureus].

Methicillin-resistant Staphylococcus aureus (MRSA) were isolated from samples collected from various patients during 1986, and antibacterial activities of 6 aminoglycosides (AGs) (netilmicin (NTL), gentamicin (GM), sisomicin (SISO), dibekacin (DKB), tobramycin (TOB) and amikacin (AMK] and 4 beta-lactam antibiotics (cefazolin (CEZ), cefmetazole (CMZ), cloxacillin (MCIPC) and methicillin (DMPPC) against these MRSA were evaluated. Among these 6 AGs, NTL was the most potent, and its MIC50 and MIC80 were 1.56 and 3.13 micrograms/ml, respectively. Antibacterial activities of GM, SISO, DKB and TOB were weak, and MIC50's of GM and DKB were both 100 micrograms/ml, while those of SISO and TOB were 50 and greater than 100 micrograms/ml, respectively. Frequency of highly resistant specimens to AMK was rather low and its MIC50 and MIC80 were 12.5 and 25 micrograms/ml, respectively. As for antibacterial activities of the above 4 beta-lactam antibiotics, the MIC50 and MIC80 of CMZ were 6.25 and 12.5 micrograms/ml, respectively, and therefore, its antibacterial activity to MRSA is relatively good. However, MIC50's of CEZ, MCIPC and DMPPC were all greater than 100 micrograms/ml, showing poor antibacterial activities. Recently, MRSA became a problem in various fields of clinical practice, and a number of literatures reporting refractory infections caused by MRSA have been published. Since MRSA is featured as multiply resistant bacteria, it is known that MRSA is resistant to the majority of existing antibiotics (penicillins, cephems, macrolides, AGs, etc.). In 1985, we reported results of our study concerning the antibacterial activities of a number of CEPs and some of AGs against multiply resistant S. aureus including MRSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Amikacin↗
PubMed1986

Postnatal locomotion development in a neurological mutant of rolling mouse Nagoya.

Postural control skills and quadrupedal locomotor pattern in infant rolling mice, a neurological mutant, were observed in the following situations: hindlimb support when suspended, rope descent, narrow path traverse, quadrupedal locomotion on an inclined corridor, and swimming behavior when entirely submerged. Until the second week of age, rolling mice developed primitive responses similar to, or somewhat slower than, their unaffected littermates, but failed to show mature adaptive and coordinated movements from Days 16-18 onward in hinblimb support and rope descent tests. The gait was broadbased and they frequently lurched, rolled over on the side in the narrow-path and incline situations. Also, swimming behavior was extremely clumsy with varying degrees of disturbed rhythm and inconsistent movement of hindlimb paddling. These findings might result from an immature development of hindlimb muscle tonus control system and distortion of smooth and orderly sequence of hindlimb muscular contractions which characterize skillful quadrupedal locomotion.

Animals↗
PubMed1986

Adrenergic modulation of pancreatic glucagon and insulin secretion in goats.

Five goats were used to investigate adrenergic influences on the secretion of both glucagon and insulin. The secretion of glucagon was augmented via alpha-adrenergic stimulation. The secretion of insulin was enhanced by stimulation of beta-adrenergic receptors and inhibited by alpha-adrenergic stimulation.

Animals↗
PubMed1986

Generation of a new monoclonal antibody and its application for determination and purification of biologically active human gamma-interferon.

Three monoclonal antibodies (MAbs) were raised against recombinant human gamma-interferon (rHuIFN-gamma). They were specific for rHuIFN-gamma and recognized parts of the molecule other than both terminal regions. Among these MAbs, only KM48 has an ability to neutralize the antiviral activity of rHuIFN-gamma. Using KM48 in combination with polyclonal antibodies, we have developed a double-sandwich enzyme immunoassay (ELISA). This ELISA preferentially detects the biologically active form of rHuIFN-gamma, because after treatment with 1 N HCl or 0.2% SDS, or at 95 degrees C, the reactivity in the ELISA and the biological activity determined by cytopathic effect (CPE) assay decrease in parallel. In addition, the ELISA recognizes both natural and rHuIFN-gamma with almost the same sensitivity. Therefore, the ELISA is useful for detecting the biologically active conformation of rHuIFN-gamma, and possibly may be useful in both industrial production and clinical studies. rHuIFN-gamma molecules bind specifically to the immunoaffinity column using the MAb KM48 as ligands. After elution with 7 M Urea/1 M NaCl, the rHuIFN-gamma can be renatured in phosphate-buffered saline with high recovery. Thus, the column provides simple one-step purification of biologically active rHuIFN-gamma.

Animals↗
PubMed1986

A clinicopathological review of 12 autopsied cases of adult T-cell leukemia.

Twelve autopsied cases with adult T-cell leukemia (ATL) were reviewed clinicopathologically. The prognosis of three cases who had suffered from severe cutaneous lesions was much better than that of the other nine cases with no or negligible cutaneous lesions. The surface marker of leukemic cells from six cases was ordinary inducer/helper phenotype (OKT4+ and 8-), but in one case leukemic cells showed OKT4+ and 8+. In another case, a significant amount of leukemic cell infiltration was found in the thymic cortex. Calcium content in the bone of ATL cases was lower than that of the patients without ATL (control group), and six cases with ATL (50%) were complicated by severe hypercalcemia. Neither adenoma nor hyperplasia of the parathyroid glands was found in any case. In most severely hypercalcemic patients, bone trabeculae were actively absorbed by numerous osteoclasts and partly replaced by fibrous tissues. In two normocalcemic patients, skeletal calcium content was also markedly reduced by osteoporosis, but the activation of osteoclasts was inconspicuous. It was speculated that the manner of bone resorption in ATL cases was diverse and there were some clinicopathological subtypes in ATL from the viewpoints of cutaneous lesions, hypercalcemia, and bone lesions.

Adult↗
PubMed1986

Ultrastructural characterization of the retrovirus particles (Sm-MTV) liberated from the mammary tumor cell line (Sm-MT) of a house musk shrew, Suncus murinus (Insectivora).

Detailed ultrastructure of a new type of retrovirus (Sm-MTV) released by cultured cells (Sm-MT) of a spontaneous mammary tumor from a house musk shrew Suncus murinus, Insectivora, is described. The virus particles were revealed as three forms: intracellular; budding; and extracellular. The intracellular type A particles were similar in profile to those associated with mouse mammary tumor cells and tended to form a small cluster of several particles in the cytoplasm. In addition, horseshoe-shaped particles as well as smaller particles in clusters, with doughnut-shaped morphology similar in structure to type A particles, were identified near the clusters of type A particles, although in smaller numbers. The budding particles contained a doughnut-shaped nucleoid, although the nucleoids decreased in size as compared with intracytoplasmic type A particles. The extracellular virions consisted of an envelope and a centrally located nucleoid. In routinely fixed specimens, the former was covered with irregularly distributed fuzzy materials in its surface, and the latter was further composed of a small electron dense core surrounded by an intermediate layer. Tannic acid treatment of cells resulted in the visualization of surface projections on the envelope of virions. Similar projections were also detected exclusively on the plasma membrane where virus budding took place, and not on the normal plasma membrane. The presence of surface projections on the viral envelope was further confirmed by the whole-cell-mounting technique. Together with our previous results of biochemical and immunological investigations, we concluded that Sm-MTV seemed to have closer phylogenetic relatedness with type D viruses of primates than with murine mammary tumor virus.

Animals↗
PubMed1986

Calcium dependency in the growth of adult T-cell leukemia cells in vitro.

The effects of calcium, calcium antagonists, and calmodulin inhibitors on the growth of adult T-cell leukemia (ATL) cells were studied in vitro. Fresh ATL cells from patients and established ATL cell lines did not grow well in a low-calcium (less than 0.01 mM) medium. However, their growth was enhanced by the addition of calcium to the medium in a dose-dependent manner. The maximum response was induced at 4 mM calcium, which was higher than that of the normal serum calcium level, 2.5 mM. Other leukemia cells, except ATL, grew well in the low-calcium medium, and their growth was not enhanced by the addition of calcium. Calcium antagonists and calmodulin inhibitors inhibited the growth of ATL cells at the concentration of 10(-5)-10(-7) M, while they did not inhibit the growth of other leukemia cells. Furthermore, the expression of interleukin 2 receptors (Tac antigens) on ATL cells was also enhanced by calcium and was inhibited by calcium antagonists and calmodulin inhibitors. In accordance with these results, the increase of the extracellular calcium concentration resulted in the increase of the intracellular calcium concentration in ATL cells, but not in other leukemia cells. These results suggest that calcium and calmodulin play a critical role in regulating the growth of ATL cells.

Calcium↗
PubMed1986

Immunosuppressive factors from adult T-cell leukemia cells.

The mechanism of immunodeficiency in adult T-cell leukemia (ATL) patients was studied in vitro. Peripheral blood lymphocytes from ATL patients and ATL cell lines such as Hut 102, MT 1, and MT 2 were not activated to proliferate by the stimulation with concanavalin A and suppressed normal lymphocyte proliferative responses induced with concanavalin A when cultured together. The sera from ATL patients and the culture supernatants from ATL cells and ATL cell lines also suppressed normal lymphocyte proliferative responses induced with concanavalin A. By Sephacryl S-200 column chromatography, the suppressive factors were fractionated as a single peak with the molecular weights of 50,000 to 70,000. The suppressive factors were unstable to acid treatment but stable to the treatment with base, heat, freezing-thawing, and trypsin. The factors suppressed the production of interleukin 2 by T-cells and the responsiveness of T-cells to interleukin 2, but not the expression of interleukin 2 receptors on T-cells and the production of interleukin 1 by monocytes. These results suggest that the immunosuppressive factors produced by ATL cells have some roles in the induction of immunodeficient states in ATL patients.

Cell Line↗