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Biomedical subjects

R Suzuki

Publications and source records attributed to R Suzuki.

At least 667 records · Page 37Linked to original sources
PubMed1985

Characterization of a Mr = 56,000 polypeptide associated with 10S DNA polymerase alpha purified from calf thymus using monoclonal antibody.

Existence of a Mr = 56,000 polypeptide associated with 10S DNA polymerase alpha was shown by production of a monoclonal anti-calf thymus 10S DNA polymerase alpha antibody secreted from a hybridoma line named 3H1. The antibody bound three polypeptides with Mr = 180,000, 56,000 and 32,000 in hydroxylapatite fraction of 10S DNA polymerase alpha by immunoblot. The antibody co-precipitated the polypeptides with the large polypeptide (Mr = 150,000-140,000) of 10S DNA polymerase alpha with the aid of second antibody. Among three polypeptides, the Mr = 56,000 polypeptide was co-purified with DNA polymerase alpha through DNA-cellulose chromatography and repeated sucrose rate-zonal centrifugations. The Mr = 56,000 polypeptide was still associated with 10S DNA polymerase alpha after second sucrose rate-zonal centrifugation, but the amount of it was reduced. The polypeptide was banded at pH 7.2-8.0 and displayed microheterogeneity in respect of isoelectric point by isoelectrofocusing with 7 M urea, and showed weak DNA-binding property after blotting onto a nitrocellulose. The antibody against the polypeptide precipitated DNA polymerase alpha from human, rat, and mouse, and Mr = 56,000 and 32,000 polypeptides were detected in these DNA polymerase alpha fractions by immunoblot. These results suggest that the polypeptide with Mr = 56,000 may take part in the DNA polymerase reaction.

Animals↗
PubMed1985

Interleukin 1-like factors can accumulate 5-hydroxytryptamine in the liver of mice and can induce hypoglycaemia.

After the injection into mice of culture medium of P388D1 cells, a murine macrophage cell line, 5-hydroxytryptamine accumulated in the liver and blood glucose declined. The factors capable of inducing these responses were purified by gel filtration and chromatofocusing. With these procedures, the activity to induce the increase in 5-hydroxytryptamine in the liver accompanied the activity to induce hypoglycaemia. Moreover, through the purification, the factors were found in the fraction of interleukin 1, a lymphocyte-activating factor. These results suggest that the factors capable of inducing the increase in 5-hydroxytryptamine and hypoglycaemia are likely to be interleukin 1 molecules or molecules closely related to interleukin 1. The present and previous findings together with those in the literature support the idea that the increase in 5-hydroxytryptamine in the liver might be a cause of hypoglycaemia. These findings may provide new and important information about the roles of macrophages in inflammation or in immune responses.

Animals↗
PubMed1985

Induction of ornithine decarboxylase in the liver and spleen of mice by interleukin 1-like factors produced from a macrophage cell line.

Injection of culture medium of P388D1 cells, a murine macrophage cell line, into mice produced a rapid induction of ornithine decarboxylase in the liver and spleen. The ornithine decarboxylase-inducing factor in the medium was purified by gel-filtration and chromatofocusing. With these procedures, the factor was usually found in the fraction of interleukin 1 (a lymphocyte-activating factor), indicating that the factor is identical with interleukin 1 or a molecule closely related to interleukin 1. The ornithine decarboxylase induction by the factor was suppressed by cycloheximide, but actinomycin D did not suppress the induction, or rather enhanced it. These findings may provide valuable information on the important roles of macrophages in immune responses or in inflammatory reactions.

Animals↗
PubMed1985

Total pelvic exenteration for advanced carcinoma of the lower colon.

Thirteen patients with advanced carcinoma of the lower colon and no evidence of extrapelvic metastasis were submitted to total pelvic exenteration. Nine of the 13 patients had ureteral urinary diversion by the ileal segment conduit. Three had colonic conduit bladder using the terminal portion of the descending colon. One patient had bilateral uretero colonic anastomosis. The operative mortality rate was 7.7%. Determinate 5-year survival rate of 38.5% was achieved. Histological examinations of the surgical specimen revealed associated abscesses adjacent to the tumor in six cases, although the cancer extended to the bowel wall and adhered to the surrounding structures in all specimens. Total pelvic exenteration assures a better quality of life, lessening of symptoms, disease control and, in selected patients, a cure.

Adenocarcinoma↗
PubMed1985

Diagnosis and operation for locally recurrent rectal cancer.

Local recurrence of rectal cancer following abdominoperineal resection is rarely amenable to limited resection. Six patients with deeply invading recurrent lesions had pelvic exenteration combined with sacral resection. This procedure seems a reasonable treatment for palliation and the chance of cure in selected patients. In order to select good candidates for this extensive procedure, carcinoembryonic antigen (CEA) assays and the diagnosis of locally recurrent tumor with pelvic computed tomography (CT) were evaluated. CEA assay is valuable for diagnosing most recurrent rectal cancers, but it is inadequate for early detection. A high CEA level often indicates extrapelvic tumor spread. CT examination is very valuable for the early detection and localization of recurrence in relation to pelvic structures.

Adenocarcinoma↗
PubMed1985

Ultrastructural observations on the transvascular route of protein removal in vasogenic brain edema.

Micro-blood vessels (MBVs), located in the area of edema, were studied in cat brain at various time intervals (1 h, 24 h, 7 days) after cold-lesion injury. Both cold-injured and adjacent gyri were examined for blood-brain barrier (BBB) permeability to i. v. injected horseradish peroxidase (HRP) with circulation times of 40 min and 24 h. Evans blue (EB) was used as a tracer for gross evaluation of the extension of brain edema. Localization of alkaline phosphatase (AP) and binding of cationized ferritin (CF), considered as a marker of anionic sites, were also studied ultrastructurally. Twenty-four hours after cold injury, the extravasated edema fluid, outlined by EB tracer, was observed to be spreading through the white matter (WM) into the adjacent gyrus. At this time, numerous, larger than capillary MBVs, presumably arterioles and venules located in the edematous WM, showed accumulations of HRP injected at the time of the operation, in the basement membrane, in abluminal pits, and in numerous pinocytotic vesicles and vacuoles of endothelial cells (ECs). The animals killed after 24 h with 40 min HRP circulation showed extravasation of HRP tracer in a zone underlying the necrotic cold injury lesion. On the other hand, there was no evidence of an abnormal HRP leakage in the further removed areas of edema in the WM, particularly in the adjacent gyrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1985

Incongruence of regional cerebral blood flow increase and blood-brain barrier opening in rabbits at the onset of seizures induced by bicuculline, methoxypyridoxine, and kainic acid.

Cerebral blood flow (CBF) was estimated using [3H]nicotine as tracer in 18 discrete rabbit brain regions at the onset of generalized seizures induced by bicuculline (BC), methoxypyridoxine (MP), and kainic acid (KA) and compared with the previously described regional pattern of blood-brain barrier (BBB) opening. Regional CBF increased 3- to 5-fold in BC-seizures, 2- to 3-fold (except in inferior colliculus) in MP-seizures, and twofold (no change in inferior colliculus) and periaqueductal gray) in KA-seizures. In general, CBF elevation was greater in areas with a high original CBF, and below average in regions with a low control value. However, under each condition a few areas did not follow this rule, viz. the occipital cortex and the basal part of the cerebellar vermis with low flow values in BC-seizures, the inferior colliculus with no change and the pallidum with a relatively high flow during MP-seizures, and limbic system areas with an exceptionally high flow during KA-seizures. The usual rise in arterial blood pressure (BP) at the onset of the seizure, necessary for the development of a BBB lesion, was absent in a few animals with BC- and MP-seizures, yet, their CBF was elevated in most regions although to a lesser extent. No relationship appeared to exist between the rise in CBF and the regional pattern of BBB opening. It is concluded that a loss of cerebral autoregulation is a prerequisite for BBB leakage, but the location of the opening is determined by neuronally derived factors which differ from convulsant to convulsant and from brain region to brain region.

Animals↗
PubMed1985

Isolation and characteristics of a leukemia-growth-promoting factor from calf thymus.

Leukemia-growth-promoting factor (LGPF) as we previously reported stimulates the growth of a murine leukemia subline (L17R) extensively. LGPF was isolated and 10(4) fold purified from calf thymuses by a combination of ammonium sulfate precipitation, Sephadex G-100 chromatography, hydroxylapatite chromatography, and Mono S-fast protein liquid chromatography (Mono S-FPLC). The mol. wt of LGPF was estimated to be approximately 25,000 a.m.u. from the elution pattern of Sephadex G-100 chromatography. The activity had high affinity for Mono S beads which are cation exchangers. Mono S fractions of LGPF are effective at a low concentration of 5 ng/ml. The activity was inactivated by heat (56 degrees C, 30 min), 1 mg/ml trypsin (37 degrees C, 1h), and 50 mM dithiothreitol (20 degrees C, 1h). The growth L17R leukemia cells are not only stimulated by LGPF, but also by pituitary and brain fibroblast growth factor (FGF). These data strongly suggest that LGPF is a heat sensitive cationic protein(s) acting as a member of FGF family.

Animals↗
PubMed1985

A new homogeneous enzyme immunoassay. Its application to measurement of alpha-fetoprotein.

A rapid and sensitive homogeneous enzyme immunoassay (homogeneous EIA) was developed for determination of serum proteins such as alpha-fetoprotein (AFP). There are two assay systems, one is a competitive system including horseradish peroxidase (HRP)-labeled antigen, antibody and substrate, and the other is a non-competitive system including HRP-labeled antibody and substrate. When the aggregate was formed through the binding of HRP-labeled AFP and anti-AFP antibody or through the binding of HRP-labeled anti-AFP antibody and AFP, HRP of the aggregates, as compared with HRP of free conjugates, exhibited marked activity in the presence of 35 mM H2O2. The extent of stimulation of HRP activity depended on the amount of AFP. This new assay method is very simple and sensitive, and can be used for the determination of any kind of protein, hormone, or drug.

Antibodies↗
PubMed1985

Arabinosylnucleoside 5'-triphosphate inhibits DNA primase of calf thymus.

It has been shown that DNA primase activity is tightly associated with 10S DNA polymerase alpha from calf thymus and that the ribonucleotide-dependent DNA synthesis is more sensitive to araCTP than DNA-primed DNA synthesis (Yoshida, S., et al. (1983) Biochim. Biophys. Acta 741, 348-357). Here we measured DNA primase activity using poly(dT) template or M13 bacteriophage single-stranded DNA template and primer RNA synthesis was coupled to the reaction by Escherichia coli DNA polymerase I Klenow fragment. By this method, the primer RNA synthesis can be measured independently of the associating DNA polymerase alpha. Using poly(dT) template, it was found that arabinosyladenine 5'-triphosphate (araATP) strongly inhibited DNA primase in competition with rATP. The apparent Ki for araATP was 21 microM and the ratio of Ki/Km (for rATP) was as low as 0.015. With poly(dI, dT) or M13 DNA, it was shown that araCTP also inhibited DNA primase in the similar manner. Product analysis using [alpha-32P]rATP showed that araATP inhibited the elongation of primer RNA. However, it is not likely that arabinosylnucleotides act as chain-terminators, since incubation of primer RNA with araATP did not abolish its priming activity. From these results, it is suggested that arabinosylnucleotide inhibits the initiation as well as elongation of Okazaki fragments in mammalian cells.

Animals↗
PubMed1985

Suppression of alloimmune cytotoxic T lymphocyte (CTL) generation by depletion of NK cells and restoration by interferon and/or interleukin 2.

By using rabbit antiserum to a glycolipid, ganglio-n-tetraosylceramide (ASGM1), the accessory effect of natural killer (NK) cells on the generation of alloimmune CTL in mice was investigated. When normal C3H/He mice were immunized with C57BL/6 or BALB/c spleen cells, they generated alloimmune CTL with a surface marker phenotype of Thy-1+ Lyt-1-2+ ASGM1-, preceded by early augmentation of cytotoxic activity of NK cells with a Thy-1-Lyt-1-2-ASGM1+ phenotype. Administration of anti-ASGM1 (10 microliters) in mice resulted in a complete depletion of NK activity and ASGM1+ cells in the spleen even 1 day after injection, but no changes in the proportions of T (Thy-1+) cells and their Lyt-1 and Lyt-2 subsets as revealed by an immunofluorescence analyzer (FACS) and phagocytic cells. When these anti-ASGM1-treated mice were immunized with allogeneic cells, they showed neither augmented NK activity nor generation of alloimmune CTL, and spleen cells isolated from these anti-ASGM1-treated mice produced no CTL response to alloimmunization in vitro. Normal spleen cells treated with the antiserum and complement in vitro also showed a complete NK depletion without any deterioration of T cells and their Lyt-1 and Lyt-2 subsets, and when stimulated with allogeneic cells they generated no CTL. Spleen NK (ASGM1+) cells were purified by Percoll-gradient centrifugations followed by complement-dependent killing of T cells with the use of anti-Thy-1 monoclonal antibody, and were further purified by panning methods with anti-ASGM1, giving a preparation consisting of greater than 90% ASGM1+, Ly-5+ cells, and less than 0.5% of Thy-1+, Lyt-1+, and Lyt-2+ cells. These purified ASGM1+ Thy-1- cells alone generated no alloimmune CTL in response to alloantigens, suggesting that ASGM1+ NK cells contained no precursors of alloimmune CTL. When added into NK-depleted spleen cells, they restored the normal alloimmune CTL response of the spleen cells, indicating that ASGM1+ fractions contained cells to provide an accessory function for CTL generation. Lyt-1+ cells purified by panning methods did not restore the CTL response of NK-depleted spleen cells. These results indicate that ASGM1+ NK cells, but not Lyt-1+ helper T cells contaminating ASGM1+ fractions at undetectable levels, are responsible for the accessory function. When these purified ASGM1+ Thy-1- cells were stimulated with allogeneic cells, they produced IL 2 and IFN.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Generation of activated killer (AK) cells by recombinant interleukin 2 (rIL 2) in collaboration with interferon-gamma (IFN-gamma).

Activation of human peripheral blood mononuclear cells (PBMC) by interleukin 2 (IL 2) and the role of interferon-gamma (IFN-gamma) in the IL 2-induced activation were investigated. Activated killer (AK) cells against NK-resistant tumor cell lines were induced in the medium containing recombinant IL 2 (rIL 2) and autologous serum without any other stimulating agents. AK activity was induced by doses of rIL 2 as low as 3 U/ml, and reached a maximum at 10(3) U/ml. Incubation of PBMC with rIL 2 resulted in IFN-gamma production and augmented NK activity after 1 day of culture, and in induction of AK cells and proliferative response after 2 days of culture. These results suggested that endogenous IFN-gamma was required for rIL 2-induction of AK cells and proliferative response. To prove this, PBMC were cultured with rIL 2 and rIFN-gamma or were pretreated with rIFN-gamma before culture with rIL 2. Both rIFN-gamma treatments of PBMC augmented rIL 2-induced AK activity and proliferative response. rIL 2-induced IFN-gamma production was also enhanced by the rIFN-gamma pretreatment of PBMC. The addition of anti-IFN-gamma antibody to rIL 2 cultures abrogated the rIL 2-induced NK augmentation, AK generation, and proliferative response in proportion to the decreased amounts of endogenous IFN-gamma detectable in culture. rIFN-gamma and/or rIL 2 cultures of PBMC increased Tac antigen expression on cell surfaces as measured by flow cytometry. Enhanced Tac expression by rIL 2 was abrogated by adding anti-IFN-gamma antibody. These data indicate that: 1) AK generation and IFN-gamma production are mediated by IL 2, and 2) IFN-gamma production may be required for IL 2 induction of AK cells and proliferative response. These finding are consistent with the hypothesis that AK generation involves a collaboration between IL 2 and IFN-gamma, in which IL 2 stimulates PBMC to produce IFN-gamma, which in turn acts as a differentiation signal that may be involved in the IL 2-initiated AK generation and proliferative response.

Antibodies↗