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Biomedical subjects

Y Koide

Publications and source records attributed to Y Koide.

At least 199 records · Page 11Linked to original sources
PubMed1987

The role of transfected HLA-DQ genes in the mixed lymphocyte reaction-like condition.

DR gene products are commonly thought to be involved in the induction of the mixed lymphocyte reaction (MLR). However, very little is known about the role of HLA-DQ antigens in the MLR. To address this question, we introduced DQ alpha and beta chain genes into mouse L cells, a human T-cell line, and a human premonocytoid cell line using a liposome-mediated transfer technique. The DQ alpha and DQ beta genomic clones were isolated from a DR2 DQw1 and a DR3 DQw2 phage library, respectively. The pSV2-Neo gene was introduced as a selection marker with both DQ alpha and DQ beta. The resultant transfected cells were able to bind several HLA class II monoclonal antibodies. In addition, these cells were found to be efficient in stimulating peripheral blood lymphocyte proliferation under MLR-like conditions, implying a role for HLA-DQ molecules in HLA-D typing differences.

Animals↗
PubMed1987

The interaction of recombinant IL-2 with human resting lymphocytes: blocking effects of monoclonal antibodies to IL-2 receptors.

Several lines of evidence suggest that subsets of resting lymphocytes naturally express interleukin-2 receptors (IL-2.R). Recombinant IL-2 (rIL-2) induced the enhancement of natural killer (NK) activity, the generation of activated killer (AK) cells, the proliferation of resting lymphocytes, and the production of interferon-gamma (IFN-gamma) in lymphocyte cultures. The subsets of lymphocytes mediating these responses appeared to be heterogeneous, but reside predominantly in nylon wool-passed non-T, non-B cells ("null cells" or T3- cells); in response to rIL-2, only Leu 11+T3- cells showed enhanced NK activity, and both Leu 11+T3- and Leu11-T3- cells showed predominantly AK activity, proliferation and production of IFN-gamma. These findings suggest that the T3- fraction (null cell fraction) contains predominantly cells expressing IL-2.R at the resting state. Unlike the case with activated T cells, however, none of these responses was blocked by any of three monoclonal antibodies to IL-2.R, including anti-Tac antibody at any dilution. These results indicate that IL-2.R on the resting T3- cells possess unique biological features compared to those on activated T or B cells. A most likely explanation is that T3- cells possess higher affinity IL-2.R than activated T or B cells. Other possibilities are also discussed.

Antibodies, Monoclonal↗
PubMed1986

Effects of parenteral palatinose on glucose metabolism in normal and streptozotocin diabetic rats.

The present experiment was carried out to investigate the metabolism of palatinose (6-O-alpha-D-glucopyranosyl-D-fructose) in the rat. The bolus injection of palatinose (0.5 g/kg) in the tail vein of normal and streptozotocin (STZ) diabetic rats caused significant increments in glucose and insulin concentrations. However, in severe STZ diabetic rats (greater than 300 mg/dl of fasting plasma glucose) no significant change in glucose and insulin concentrations was observed. In liver perfusion, the gradual decrease in glucose output from the normal and mild STZ diabetic rat livers perfused with 20 mM Krebs-Ringer-Tris buffer pH 7.4 was prevented by the addition of 5.5 mM palatinose in the perfusate and fructose was detected in the effluent during the palatinose infusion. The results indicate that palatinose is metabolized to glucose and fructose in both normal and diabetic rat tissues, and this causes the increase in blood glucose concentration. On the other hand, the direct stimulatory effect of insulin release from pancreatic B-cell was not observed when the palatinose was infused into the isolated perfused rat pancreas. The study suggest that palatinose administered parenterally is metabolized by tissues and expected to be used as a source of fluid and energy supply.

Animals↗
PubMed1986

Cloning and sequencing of the major intracellular serine protease gene of Bacillus subtilis.

A Bacillus subtilis 2.7-kilobase DNA fragment containing an intracellular protease gene was cloned into Escherichia coli. The transformants produced an intracellular protease of approximately 35,000 Mr whose activity was inhibited by both phenylmethylsulfonyl fluoride and EDTA. Introduction of the fragment on a multicopy vector, pUB110, into B. subtilis caused a marked increase in the level of the intracellular protease. The nucleotide sequence of the cloned fragment showed the presence of an open reading frame for a possible proenzyme of the major intracellular serine protease (ISP-I) of B. subtilis with an NH2-terminal 17- or 20-amino-acid extension. The total amino acid sequence of the protease deduced from the nucleotide sequence showed considerable homology with that of an extracellular serine protease, subtilisin. The transcriptional initiation site of the ISP-I gene was identified by nuclease S1 mapping. No typical conserved sequence for promoters was found upstream of the open reading frame. An ISP-I-negative mutant of B. subtilis was constructed by integration of artificially deleted gene into the chromosome. The mutant sporulated normally in a nutritionally rich medium but showed decreased sporulation in a synthetic medium. The chloramphenicol resistance determinant of a plasmid integrated at the ISP-I locus was mapped by PBS1 transduction and was found to be closely linked to metC (99.5%).

Amino Acid Sequence↗
PubMed1986

Alterations in activities of calmodulin and heat-stable calmodulin-binding protein in rat testis.

Effects of postnatal development, surgical cryptorchidism, and hypophysectomy on the activity of calmodulin and of a 32,000-molecular weight (32) calmodulin-binding protein (Ono et al., J. Biol. Chem. 259: 9011-9016, 1984) were examined in rat testis. In adult rats, approximately 95% of their activities distributed in seminiferous tubule preparation, and most of them were in the 105,000-g supernatant. Both activities were low early in the development, but the calmodulin activity increased between 25 and 45 days of age, and the 32 K calmodulin-binding protein activity increased between 35 and 45 days of age. In contrast, surgical cryptorchidism caused a rapid decline in their activities in the abdominal testis, whereas their activities in a scrotal testis did not decline. Hypophysectomy similarly resulted in a gradual decline in their activities. Replacement of follicle-stimulating hormone or testosterone for 7 days from 30 days after hypophysectomy did not quantitatively restore either the testes weight or the activities of the proteins. The results indicate a primary distribution of both proteins in mature germ cells.

Animals↗
PubMed1986

Selective elimination of anti-DNA antibody-producing cells by antiidiotypic antibody conjugated with neocarzinostatin.

A new strategy was shown for the manipulation of autoantibody production in humans. Antiidiotypic antibody to human anti-DNA autoantibody was conjugated with neocarzinostatin (NCS), a cytotoxic agent, by using N-succimidyl 3-(2-pyridyldithio) propionate as a coupling agent. Human B cell clones, which produce anti-DNA autoantibodies, were killed by in vitro treatment with antiidiotype (Id)-NCS conjugates, while clones expressing an Id with irrelevant specificity were unaffected. These results indicate that treatment with anti-Id-NCS conjugates can act as a potent and specific means of generating immunosuppression of autoantibody production. This approach will have a significant advantage in aborting clones that are not effectively suppressed for the autoantibodies by anti-Id antibodies alone, and will result in a potential therapeutic treatment for systemic lupus erythematosus.

Antibiotics, Antineoplastic↗
PubMed1986

Responsiveness of hypophyseal-adrenocortical axis to repetitive administration of synthetic ovine corticotropin-releasing hormone in patients with isolated adrenocorticotropin deficiency.

The primary lesion site in isolated ACTH deficiency was studied in three patients by examining the responses of immunoreactive ACTH to insulin-induced hypoglycemia, lysine vasopressin, and synthetic ovine corticotropin-releasing hormone (CRH). In all patients, no significant changes in immunoreactive ACTH followed insulin-induced hypoglycemia or lysine vasopressin. Fifty micrograms (greater than or equal to 1 microgram/kg BW) of CRH administered as an iv bolus dose daily for 6 consecutive days elicited no significant increase in plasma immunoreactive ACTH, beta-lipotropin, or cortisol levels in all patients. Eight iv bolus injections of 0.63 microgram/kg BW CRH at 4-h intervals also failed to induce a significant response of immunoreactive ACTH to an iv bolus dose of 1 microgram/kg CRH at 36 h in one patient. In contrast, a single bolus dose of 50 micrograms CRH induced a response of plasma immunoreactive ACTH in a patient with Cushing's disease and a patient with Addison's disease. The present results suggest that the primary lesion of isolated ACTH deficiency is not the hypothalamus, but, rather, is located in pituitary ACTH-secreting cells.

Addison Disease↗
PubMed1986

Impaired mineral metabolism in Cushing's syndrome: parathyroid function, vitamin D metabolites and osteopenia.

To clarify the mechanism for the impaired mineral metabolism in Cushing's syndrome, the clinical features, biochemical parameters before and after oral calcium load, and vitamin D metabolism were compared between two groups of patients of endogenous Cushing's syndrome (17 cases) with and without osteopenia. The patients with osteopenia [OP (+): 7 cases, all female] were older (42.7 +/- 8.3 y. o.) and had a longer duration (117 +/- 75 M) of the syndrome than those without osteopenia [OP (-): 33.8 +/- 8.9 y. o., 36 +/- 25 M]. OP (-) showed a blunted hypercalciuria after oral calcium load (63.7 +/- 20.4 to 90.9 +/- 36.1 mg/g X Cr), while OP (+) had higher levels of urinary excretion of calcium (fasting: 120.4 +/- 37.5, and after oral calcium load: 235.6 +/- 72.6 mg/g X Cr), of cyclic AMP (7.6 +/- 1.1 nmol/dl X GF), and of plasma 1.25(OH)2D (76.6 +/- 34.0 pg/ml) than OP (-) (u-cAMP: 3.2 +/- 2.0 nmol/dl X GF, 1,25(OH)2D: 27.9 +/- 16.3 pg/ml). These results indicate that 1) elderly female patients with Cushing's syndrome of long duration are susceptible to OP, 2) during the early phases of the syndrome, reduced intestinal calcium absorption with sustained calciuria (probably through the inhibition of calcium reabsorptive effect of PTH by glucocorticoid) induces negative calcium balance, leading to 3) a development of secondary hyperparathyroidism which stimulates 1,25(OH)2D synthesis. Thus, the mechanism involving bone resorption stimulated by excess PTH along with the direct inhibition of bone formation by glucocorticoid seems to play an important role in a progressive development of OP in Cushing's syndrome.

Adult↗
PubMed1986

Time course of ketone body production in the isolated perfused rat liver in response to various stimuli.

Using a non-recirculating perfusion system, we studied the time course of ketone body output from the isolated rat liver in response to various hormones and changes in pH and redox state. The release of 3-hydroxybutyrate (3-OHB) started to be suppressed within 1 min after the addition of insulin (50 mU/ml) and kept half of the basal level even 10 min after its cessation. The addition of glucagon (0.2 microM) caused an increase in both 3-OHB and acetoacetate (AcAc) outputs from fed livers within 5 min, which reached about 150% of the basal level 10 min after the infusion and maintained a constant level through out the experiment. Growth hormone (2 mu/ml) elicited a slight but significant increase in AcAc output soon after the infusion. Epinephrine (10 microM) also caused a slight increase in both AcAc and 3-OHB outputs 9 min after the infusion and maintained a significant increase even 10 min after stopping infusion. The decrease in pH of the perfusate or the addition of ascorbic acid abruptly suppressed the AcAc production. In summary, the present study clearly demonstrated the direct effects of various hormones on ketogenesis in the liver and the usefulness of a non-recirculating liver perfusion system as a tool for the study of ketogenesis.

Animals↗
PubMed1986

Unstability of neocarzinostatin-chromophore.

The unstability of neocarzinostatin (NCS), apo-NCS and NCS-chromophore (NCS-chr) has been investigated by using an extra-weak chemiluminescence (CL) analyzer. A significantly high emission intensity (10,840 counts/10 seconds) was detected from NCS under dark conditions at 20 degrees C, while no significant emission was observed in other antitumor antibiotics, such as, mitomycin C and pepleomycin. This high emission intensity of NCS was due to NCS-chr I (epoxide form) but not apo-NCS. The functional group generating the high extra-weak CL of NCS-chr I is probably the epoxide in the molecule, since the emission intensity of NCS-chr I (epoxide form) is much higher than that of NCS-chr II (hydrochloride adduct form). The extra-weak CL emission of NCS decreased under a nitrogen atmosphere and it was greatly enhanced under an oxygen atmosphere. The spectral analysis of NCS showed emission peaks around 460 and 570 nm. These observations strongly suggest that one of the emission species of NCS-chr may be due to singlet oxygen.

Antibiotics, Antineoplastic↗
PubMed1986

[Studies on the antitumor activity of human recombinant interferon alpha-2b in vitro].

Correlation between antiproliferative and binding activities of interferon (IFN) alpha-2b to various human cell lines was examined using human recombinant IFN alpha-2b. Burkitt's lymphoma Daudi cells and human renal cell carcinoma OS-RC-2 cells were sensitive to IFN alpha-2b, whereas two EB-virus-transformed B cell lines, FS and L-KT3, and human A375 melanoma cells showed low or no sensitivity. 125I-IFN alpha-2b binding assay revealed that the difference in IFN alpha-2b sensitivity was related to the number and the affinity of IFN alpha-2b receptors per cell. Experiments were then performed to investigate the influence of recombinant IFN alpha-2b on the cytostatic activity of monocytes against A375 cells in vitro. IFN alpha-2b enhanced the cytostatic activity of monocytes against A375 cells which showed low sensitivity to the direct growth inhibitory effect of IFN alpha-2b. Depletion of NK cells from the monocyte preparations by anti-Leu-11b monoclonal antibody and complement did not affect the monocyte activation by IFN alpha-2b, indicating that NK cells were not involved in this system.

Burkitt Lymphoma↗