PubMed Health⌕ Search

Biomedical subjects

T Iwaguchi

Publications and source records attributed to T Iwaguchi.

At least 37 records · Page 2Linked to original sources

Characterization of two possible forms of type IV collagen from human kidney cortex.

Type IV collagen was isolated from human kidney cortex according to the purification of mouse kidney type IV collagen (MKIVC) with minor modifications as described previously [Oikawa, T., et al. (1986) Chem. Pharm. Bull. 34, 789-797]. Chromatography of human kidney type IV collagen (HKIVC) on a column of DEAE-cellulose resulted in its separation into two fractions, i.e., one (HKIVC-1) passed through and the other (HKIVC-2) adsorbed to the column, similar to MKIVC. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Bio-Gel A-5m chromatography revealed that both HKIVC-1 and -2 differed from each other in the ratios of major and minor components. Amino acid analyses also demonstrated that there was a significant difference in the contents of several amino acid residues between both type IV collagens and their 80-kDa components, one of the major ones. These results indicate the possibility that there exist two forms of type IV collagen in human kidney.

Amino Acids↗

Angiogenic activity of rat mammary carcinomas induced by 7,12-dimethylbenz[a]anthracene and its inhibition by medroxyprogesterone acetate: possible involvement of antiangiogenic action of medroxyprogesterone acetate in its tumor growth inhibition.

The significant inhibitory activity of medroxyprogesterone acetate (MPA) against mammary tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) was confirmed in female Sprague-Dawley (SD) rats, and was found to be independent of the estrogen receptor (ER) level. To facilitate elucidation of the mechanism underlying the antitumor activity of MPA against the rat mammary tumors (RMTs) regardless of ER status, the present study was conducted to determine whether or not a DMBA-induced RMT had the capacity to elicit angiogenic activity on tissue implantation into a rabbit cornea, and, if so, to determine whether or not the angiogenic activity of the RMT was inhibited by MPA. The RMTs obtained were classified into two groups based on the ER level; ER-positive and -negative groups. Both groups exhibited relatively strong angiogenic activity, the activity of the ER-negative group being significantly higher than that of the ER-positive one. The angiogenesis produced by both groups of RMTs was significantly inhibited by MPA, as judged from the results of the rabbit cornea assay. Similarly, MPA almost entirely suppressed not only the angiogenesis but also the growth of rabbit VX2 tumors without ER, included as a positive control as to the induction of angiogenic activity. In vitro experiments using neoplastic epithelioid RMT-1 and -2 cells cloned from DMBA-induced RMTs demonstrated that MPA had little or no suppressive effect on the growth of these epithelial cells. These results suggest that the inhibitory action of MPA toward the angiogenic activity of RMTs, at least in part, involves its antitumor activity toward the RMTs.

9,10-Dimethyl-1,2-benzanthracene↗

A new aminopeptidase in monkey cerebral membrane fraction: hydrolysis of enkephalin.

A new aminopeptidase, which cleaves the Tyr1-Gly2 bond of enkephalin, was partially purified from the monkey brain membrane fraction. The molecular weight of the enzyme was estimated to be about 53,000, and the optimum pH was in the neutral region (pH 6.5). The enzyme hydrolyzed Leu-enkephalin with a Km value of 238 microM. It strongly hydrolyzed L-tyrosine and L-leucine beta-naphthylamide, but showed only weak affinity for L-arginine or L-alanine beta-naphthylamide. The enzyme was much more potently inhibited by bestatin (IC50: 2 x 10(-8) M) than the other specific aminopeptidase inhibitors examined, while it showed low sensitivity to puromycin and actinonin, inhibitors of cerebral enkephalin-degrading aminopeptidase and aminopeptidase M, respectively. These results indicate that the new enkephalin-degrading aminopeptidase is clearly distinct from aminopeptidase M, which has been reported to be a key enzyme in enkephalin inactivation.

Aminopeptidases↗

Immunological characterization and clinical significance of low mobility cells appearing in the peripheral blood mononuclear cells of cancer patients.

The characteristics of low mobility cells (LMC) in the peripheral blood mononuclear cells (PBMC) of cancer patients were studied using a Parmoquant-L, a fully automated electrophoresis instrument, and a fluorescence-activated cell sorter (FACS). The L/H ratio (%) of LMC (less than 0.95 micron/s/V/cm) to high mobility cells (HMC) (greater than or equal to 0.95) was used to analyze the electrophoretic mobility (EPM) histogram of PBMC. In the cancer patient, the L/H ratio increased as a result of the appearance of LMC. As the ratio closely correlated with clinical stage of cancer, recurrence of cancer, and performance status in the patients, the method is a useful parameter for prognosis of cancer, practically, for early detection of recurrence in the follow-up study of cancer patients. The EPM of monocytes and subsets of lymphocytes was determined to characterize LMC. Monocytes were in LMC. T-Cells such as helper/inducer (Leu-3+), suppressor (Leu-2+Leu-15+) and cytotoxic (Leu-2+Leu-15-) cells and natural killer (NK) cells (Leu-7+ or Leu-11+) were in HMC. The percentage of monocytes correlated significantly with the mean EPM of PBMC. In cancer patients, the percentage of monocytes increased significantly. On the other hand, suppressor T-cells did not increase enough to account for LMC. The appearance of suppressor T-cells correlated with that of monocytes. These results suggest that LMC in cancer patients consisted of mainly monocytes rather than suppressor T-cells.

Cell Adhesion↗

Characterization of suppressor T-cells induced with concanavalin A in vivo by cell electrophoresis.

The splenic T-cells of concanavalin A (Con-A)-injected mice suppressed the in vitro Con A-induced splenic blastogenesis of normal mice. We examined electrophoretic mobilities (EPM) and surface markers of Con A-induced suppressor T-cells as a model of suppressor T-cells. The EPM of the suppressor cells with both Thy-1 and gangliotetraosyl-ceramide (asialo GM1) was lower than that of normal T-cells. The ratio of low mobility T-cells (LMT) to high mobility T-cells (HMT) correlated significantly with dose-response and time-course of Con A in the suppressor activity and with the percentages of cells carrying asialo GM1 antigen and receptor for peanut agglutinin. For in vitro induction by Con A, Lyt-2+ cells were reported to have suppressor activity. However, for in vivo induction by Con A, Lyt-2+ cells did not correlate with the suppressor activity in the dose-response and time-course experiments. By separating the Lyt-subsets, it was found that both Lyt-1+2+ and Lyt-1+2- subsets were suppressor cells in the blastogenesis. The suppressor activity of in vivo Con A-induced spleen cells correlated with the LMT/HMT ratio, but not with the analysis of Lyt-phenotype. These results suggested that lymphocytes electrophoresis clearly distinguished Con A-induced suppressor T-cells with low EPM from normal T-cells.

Animals↗

Essential requirement of I-A region-identical host bone marrow or bone marrow-derived cells for tumor neutralization by primed L3T4+ T cells.

The antitumor activity of Meth A-hyperimmunized BALB/c mouse spleen cells (Meth A-Im-SPL) was assayed by the Winn test in H-2 incompatible bone marrow chimeras in closed colony CD-1 (nu/nu), inbred DDD/1(nu/nu) (H-2s), or inbred BALB/c(nu/nu) (H-2d) mice as recipients. We found that Meth A-Im-SPL suppressed Meth A growth in the chimera nude mice which were reconstituted with bone marrow cells of the H-2d haplotype (i.e., BALB/c, DBA/2 and B10.D2), but not in the chimeras which were reconstituted with bone marrow cells of the H-2a, H-2b, or H-2k haplotype (i.e., B10.A, B10, and B10.BR). These results suggested that H-2 restriction occurred between Meth A-Im-SPL and bone marrow or bone marrow-derived cells in tumor neutralization. Furthermore, Meth A-Im-SPL did not suppress Meth 1 tumors (antigenically distinct from Meth A tumors) in the presence or absence of mitomycin C-treated Meth A in a Winn assay. These results suggested that there is tumor specificity in the "effector phase" as well as in the "induction phase". The phenotype of the effectors in the Meth A-Im-SPL was Thy-1.2+ and L3T4+, because Meth A-Im-SPL lost their antitumor activity with pretreatment with anti-Thy-1.2 monoclonal antibody (mAb) and complement or anti-L3T4 mAb and complement, but not with anti-Lyt-2.2 mAb and complement or complement alone. Positively purified L3T4+ T cells from Meth A-Im-SPL (Meth A-Im-L3T4), obtained by the panning method, suppressed the tumor growth in the chimera nude mice which were reconstituted with bone marrow cells of B10.KEA2 mice (that were I-A region-identical with Meth A-Im-L3T4 cells but not others in H-2) as well as B10.D2 cells (that were fully identical with Meth A-Im-L3T4 cells in H-2). We conclude that Meth A-Im-SPL (L3T4+) neutralized the tumors in collaboration with I-A region-identical host bone marrow or bone marrow-derived cells, and the neutralization was not accompanied by the "bystander effect."

Animals↗

Determination of an immunosuppressive substance in serum by latex particle electrophoresis.

The level of immunosuppressive substance (IS), which increases in the serum of patients with cancer, was determined by an assay based on particle electrophoresis. Polystyrene latex particles (PLP) were coated with IS, which was extracted from the ascitic fluid of patients with cancer. The IS was a glycoprotein with a molecular weight of about 52,000, and an isoelectric point in the range pH 2.7-3.3. When the IS on the surface of the PLP reacted with the anti-IS antibody, the mean electrophoretic mobility of the PLP changed from -3.16 to +0.21 micron.s-1.V-1.cm in the medium of pH 7.2 and ionic strength I = 0.0154. After preincubation of anti-IS antiserum and tested serum, the PLP coated with IS were added to this solution. It was incubated again and then the surface charge of the PLP was measured by an automatic cell-electrophoretic instrument. This method was used to determine the IS concentration in the serum of cancer patients and pregnant women. When compared to healthy controls, the serum IS level was significantly higher in patients with cancer, and lower in pregnant women. The assay based on latex-particle electrophoresis proved to be a sensitive and rapid method for determining the IS level in serum.

Electrophoresis↗

Comparative studies on estrogen receptors between a pregnancy-dependent mouse mammary tumor (TPDMT-4) and related autonomous tumors.

TPDMT-4 is a pregnancy-dependent mouse mammary tumor line characterized by progressive growth in pregnant, but dormancy in virgin, hosts and by significant estrogen (ER) and progesterone receptor (PR) levels. Three sublines, T4-OR26, T4-0I96, and T4-0I320, were established from sporadic outgrowths in virgins of TPDMT-4 pieces passaged long in breeding and estradiol (E2)- plus progesterone-treated mice and of enzymatically dissociated TPDMT-4 cells, respectively. T4-OR26 tumors produced ovarian-responsive growth and maintained the parent levels of ER and E2-dependent PR. T4-OI320 and T4-OI96 tumors were ovarian independent or autonomous. The former had ER, but not E2-dependent PR, and the latter had neither. To clarify the mechanism of acquisition of autonomy by hormone-dependent neoplastic cells, comparative ER studies were conducted between TPDMT-4 and T4-OI320 tumors. Although cytosolic, microsomal, and nuclear translocated ER levels were generally lower in T4-OI320 tumors, the dissociation constants, determined by the dextran-charcoal technique, steroid specificity, sedimentation data in sucrose gradients, and activation studies using DNA binding, molecular transformation from 4S to 5S, and [3H]E2 dissociation from [3H] E2-ER complexes as markers, revealed no autonomy-specific changes in cytosolic ER. Small but significant differences in the affinity of [3H]E2 to nuclear ER and the [3H]E2 dissociation rate from nuclear bound [3H]E2-ER complexes were found between both tumors. Hormone-dependent tumors may progress toward autonomy with different receptor statuses in different environments, and lack of E2-dependent PR synthesis in ER-positive tumors may be due to defects at postreceptor or nuclear levels involving subtle changes in interaction between activated ER and nuclei.

Animals↗

The collaboration of H-2 identical bone marrow cells in in vivo antitumor activity of immune mouse splenocytes.

Antitumor activity of Meth A-immune BALB/c mouse spleen cells (Meth A-Im-SPL) was assayed by a Winn test in CD-1(nu/nu) or BALB/c(nu/nu) chimeric mice which were reconstituted with the bone marrow cells of various strains of mice. It was found that Meth A-Im-SPL (L3T4+ T cells) neutralized the tumor in collaboration with H-2 compatible bone marrow or bone marrow-derived cells.

Animals↗

Effects of PSK, an antitumor protein-bound polysaccharide, on the surface charge of lymphocytes in X5563-bearing mice.

Spleen and thymus cells from X5563 plasmacytoma-bearing mice treated with PSK (krestin) were analyzed by cell electrophoresis and flow microcytometry. A splenocyte electrophoretic pattern showed that an intermediate mobility peak (IMC), which appeared between the low (B cells) and high (T cells) peaks as the tumor developed, was depressed by the administration of PSK. Thy-1+ cells and asialo-GM1+ (aGM1+) cells decreased with tumor growth, and null cells without a marker of Ig, Thy-1 nor aGM1 increased. However, these changes were corrected by the administration of PSK. As the tumor grew, a thymocyte electrophoretic pattern showed that the incidence of low mobility cells, corresponding to immature cells, decreased, and that of high mobility cells, corresponding to mature cells in the medullary zone, increased. However, PSK suppressed the changes. The tumor did not disappear but life span was prolonged (121%) by the administration of PSK. These results lead to the conclusion that the administration of PSK prevented the changes in surface charge and markers of lymphocytes due to tumor burden, and restored the immunological responsiveness even in the syngeneic system.

Adjuvants, Immunologic↗

The Lyt phenotype of the T cells responsible for in vivo tumor rejection in syngeneic mice.

Spleen cells of BALB/c mice hyperimmunized with a transplantable methylcholanthrene-induced sarcoma Meth A (Meth A-Im-SPL) inhibited the growth of Meth A tumor in vivo in a tumor neutralizing test. Meth A-Im-SPL did not neutralize another antigenically distinct sarcoma, Meth 1, indicating that the antitumor activity is tumor specific. Lyt-1+2- cells of Meth A-Im-SPL (Im-Lyt-1+2-) were the effectors since in vitro treatment of Meth A-Im-SPL with anti-Thy 1.2 or anti-Lyt 1.2 antibody plus complement completely abrogated their neutralizing activity, whereas treatment with anti-Lyt 2.2 plus complement did not. To further confirm the effector activity of Im-Lyt-1+2- cells, T cell subpopulations were separated from Meth A-Im-SPL by the panning method. The purified Im-Lyt-1+2-, but not Im-Lyt-1+2+ cells neutralized the tumor in athymic nu/nu mice as efficiently as in +/+ mice, suggesting that the donor Im-Lyt-1+2- cells but not recipient T cells were primarily responsible for neutralizing the tumor. The present study, however, did not exclude the possible contribution of recipient T cells to the tumor neutralization and this is open to further investigation.

Animals↗

Progression from hormone dependence to autonomy and angiogenesis in mouse mammary tumours.

The transplantable pregnancy-dependent mammary tumour (TPDMT-4), the related hormone-dependent (TPDMT-4EP) and autonomous (T4-0I320 and T4-0I96) subline tumours, and the mammary glands from DDD mice were compared for angiogenic activity on the rabbit cornea by tissue implantation. The TPDMT-4EP tumour was established by serially transplanting TPDMT-4 tumour fragments in oestradiol plus progesterone treated mice. The T4-0I320 and T4-0I96 tumours directly derived from the TPDMT-4 and TPDMT-4EP tumours, respectively. Angiogenic activity was graded by macroscopic and microscopic examinations into 3 classes; negative, partial and complete angiogenesis. These tumours were comparable to mammary glands in activity and induced complete angiogenesis in only 15-23% of the implants. However, when partial and complete responses were combined as positive angiogenesis, TPDMT-4, T4-0I320, TPDMT-4EP and T4-0I96 tumour implants were angiogenic in 25, 29, 42 and 54%, respectively. The T4-0I96 tumour was significantly more angiogenic than the parent tumour but this was not so for the TPDMT-4EP tumour. Spontaneous C3H mouse mammary tumours, human gliomas from nude mice, rat Walker 256 carcinomas and rabbit VX-2 tumours induced complete angiogenesis in 54, 63, 59 and 92% of the implants, respectively. The results suggest that the TPDMT-4 tumour is unique in being weakly angiogenic and able to progress toward greater autonomy with or without augmented angiogenic activity in different conditions.

Animals↗

Evaluation of anticancer drugs by lymphocyte electrophoresis.

The spleen cells in tumor-bearing and normal mice treated with Krestin (PSK), mitomycin C (MMC) or adriamycin (ADM) were analyzed by cell electrophoresis and flow microcytometry. In normal mice, the splenocyte electrophoretic mobility histogram was observed as a bimodal pattern, and low and high mobility cells (LMC and HMC) corresponded with B and T cells, respectively. In sarcoma-180-bearing mice, an intermediate mobility peak (IMC) appeared between the low and high peaks. Although every anticancer drug depressed the IMC when the tumor was cured, MMC reduced the absolute number of splenic Ig+ and Thy-1+ cells, and ADM injured Ig+ cells in normal as well as in tumor-bearing mice. PSK, however, depressed splenomegaly by tumor-burden in spite of a slight increase in splenocytes of normal mice. In a previous paper, it was reported that the thymocyte mobility histogram was restored to a normal pattern by treatment with PSK in tumor-bearers, while it was made more abnormal by treatment with MMC because of injury to cortical thymocytes. From these results, it may be considered that an anticancer drug which restored the splenocyte mobility histogram to a normal pattern without damages to thymocytes is preferable for cancer therapy.

Animals↗

[Emergenec of low-mobility lymphocytes in the tumor-bearing status and its immunological significance].

The immunological significance of the lymphocyte mobility histogram derived from a fully automated cell electrophoretic instrument (Parmoquant-L), was considered. In mouse lymphocytes, the ratio of medullary thymocytes increased as a result of a decrease in the proportion of cortical thymocytes, whereas the ratio of splenocytes in the low-mobility zone (0.85-0.95 micron/sec/V/cm) increased in the course of tumor growth or in vivo concanavalin A-treatment. In the peripheral lymphocytes of cancer patients, the decreased ratio of high-mobility T cells resulted in a gradual increase in that of low-mobility T cells, which were not seen in lymphocytes modified by the patient's serum. Although the formation of blastoid cells by stimulation of the tumor or mitogen cannot be completely denied, the low-mobility T cells of peripheral lymphoid tissues in the tumor-bearing status are considered to be caused by incomplete differentiation of the cells, in which immunosuppressor cells are involved. Pattern analysis of lymphocyte electrophoresis would be a simple method if fully automated instrumentation was used.

Animals↗

Analysis of splenic lymphocytes with high electrophoretic mobility in adult and aged nude mice.

Electrophoretic mobility (EPM) and surface markers of splenic lymphocytes in adult (8 weeks old) and aged (over 1 year old) nude mice were investigated. Splenic lymphocytes in nude mice showed a bimodal pattern consisting of low mobility lymphocytes (LML) corresponding to B cells and high mobility lymphocytes (HML). The HML of nude mice showed the following immunological characteristics: (1) surface Ig- cells; (2) asialo GM1+ cells; (3) an increase in natural killer (NK) activity after depletion of B cells; (4) abrogation of the HML peak and NK activity after treatment with anti-asialo GM1 and complement. These findings suggested that HML in nude mice were NK cells. The mobility of NK cells was slightly lower than that of T cells in normal mice, although their histograms greatly overlapped each other. In the spleen cells of nude mice, there was a significant increase in the numbers of Thy-1+ cells and a decrease in the intensity of asialo GM1 antigen as a function of age. The surface markers of HML were Thy-1+- asialo GM1++ in adult nude mice, but were Thy-1+ asialo GM1+ in aged nude mice. However, although HML in aged nude mice became Thy-1+, these had almost the same EPM as those in adult nude mice.

Age Factors↗

In vivo inhibition of concanavalin A-induced suppressor T cells by 5-fluorouracil.

Spleen cells of mice inoculated intravenously (iv) with concanavalin A (Con A) suppressed the in vitro normal spleen cell blastogenesis. The suppressor cells, as determined by measuring the inhibition of in vitro T cell blastogenesis by Con A, were resistant to X-irradiation. They lacked surface Ig and were abrogated by treatment with alpha Thy 1.2 antibody and complement, but not with complement alone, indicating that these suppressor cells are not B cells but T cells. Inoculation of 5-fluorouracil (5-FU) inhibited the induction and/or activity of these suppressor cells, whereas that of cyclophosphamide (CY), adriamycin, vincristine, or 3-[(4-amino-2-methyl-5-pyrimidinyl)-methyl]-1-(2-chloroethyl)-1-nitro sou rea (ACNU) did not at any interval tested. Since two other antimetabolic agents, 6-mercaptopurine and 2'-deoxyguanosine, were also effective in inhibiting these suppressor T cells, it was supposed that Con A-induced suppressor T cells are metabolically more active than the other T subpopulations. The findings that CY and ACNU decreased the number of T cells as much as or more than 5-FU did, but that they did not inhibit these suppressor T cells, suggests that 5-FU more or less selectively inhibited this suppressor T-cell subpopulation.

Animals↗