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Biomedical subjects

T Kambara

Publications and source records attributed to T Kambara.

At least 109 records · Page 6Linked to original sources
PubMed1990

Serine protease-induced enhancement of blood-borne metastasis of rat ascites tumour cells and its prevention with deoxyribonuclease.

Serine proteases, such as alpha-chymotrypsin or elastase, caused an aggregation of rat ascites tumour cell lines, AH-130, AH-109A and YS, in a protein free medium which preserved the cell viability. This aggregation, which was monitored spectrophotometrically, was dependent upon the protease activities and was resistant to treatment with either a calcium chelating reagent (EDTA) or neuraminidase. However, the tumour cell aggregates were redispersed by treatment with deoxyribonuclease I (DNase I). This dispersal effect was dependent upon the DNase activity. A possible relationship between the tumour cell aggregation and development of blood-borne metastasis was studied. An intravenous inoculation in rats of tumour cell aggregates performed by the alpha-chymotrypsin treatment resulted in significantly higher numbers of lung metastatic foci than an injection of single cells. When the re-separated single cells, prepared in vitro by treatment with DNase I following alpha-chymotrypsin treatment, were injected instead of the aggregates, the enhancement of metastasis was reversed. These enhancement and reversal effects were mimicked in vivo by intravenous injections of protease and nuclease following inoculation of a single cell suspension. That is, the number of metastatic foci caused by single cell inoculation followed by an intravenous alpha-chymotrypsin injection, was higher than that in a control group receiving PBS instead of alpha-chymotrypsin. Again, this augmentation was reversed by an injection of DNase I following alpha-chymotrypsin injection. Furthermore, an injection of DNase I alone itself reduced the starting number of metastases resulting from injection of the single tumour cell suspension. These data suggest that the metastatic behaviour of tumour cells may be increased by protease inducible DNA dependent cell aggregation should it occur in the blood stream.

Animals↗
PubMed1990

In situ pulmonary responses of T cell and macrophage subpopulations to a challenge infection in mice vaccinated with irradiated cercariae of Schistosoma mansoni.

Cellular events related to the resistance induced by radiation-attenuated cercariae of Schistosoma mansoni were determined immunocytochemically in the lung tissues of mice. Thy-1, CD4, CD8, Mac-1 MOMA-1, MOMA-2, and Ia antigens were identified on cryostat sections by the immunogold-silver staining technique with specific monoclonal antibodies. In mice vaccinated with irradiated cercariae and challenged with normal cercariae, the number of Thy-1+ and CD4+ lymphocytes was increased dramatically relative to the normal numbers both in perivascular tissues and in focal cellular aggregates in the parenchyma of the lungs. A high ratio of CD4+/CD8+ T cells was noted in the aggregates, both in perivascular tissues and in the foci. Macrophages showing positive reactions for Mac-1, MOMA-1, MOMA-2, and Ia also infiltrated the foci. In control mice that were unvaccinated and challenged, foci showing positive reactions for the lymphocyte subpopulations barely were detectable in the lungs by day 14. The numbers of Thy-1+, CD4+, and CD8+ cells and the CD4+/CD8+ ratio in controls were considerably less than those in vaccinated/challenged mice over the period of observation. In conclusion, pulmonary cellular aggregates in vaccinated and challenged mice were composed mainly of Thy-1+ and CD4+ cell populations characteristic of delayed-type hypersensitivity (DTH) reactions. Thus, Thy-1+ and CD4+ cells in the lungs of vaccinated mice may be involved in the elimination of challenge parasites through DTH reactions.

Animals↗
PubMed1989

Neutrophil producing capacity of 5-lipoxygenase metabolites of arachidonic acid after major surgery.

It is well known that patients who undergo surgical operations have a high risk of infection and sepsis. One explanation for this high risk may be a depression of neutrophil functions at the postoperative period. In the present study, the effects of surgical stresses on neutrophil functions were studied in ten patients who underwent general anesthesia and major surgery. The neutrophil functions especially focused on were the producing capacities of 5-lipoxygenase metabolites of arachidonic acid such as Leukotriene B4 (LTB4), LTC4, LTD4, 6-trans-LTB4, and w-oxidation products of LTB4. Neutrophils were stimulated with calcium-ionophore A23187 (2x10(-5) M) in the presence of arachidonic acid (5x10(-5) M) for 5 minutes at 37 degrees C. The arachidonic acid metabolites were extracted by methanol. After centrifugation, the supernatant of the mixture was concentrated and applied to a C-18 column on reversed phase high performance liquid chromatography (RP-HPLC) system, monitoring the absorbance at 280 nm. In all cases, the LTB4 production significantly increased postoperatively with an increment of 6-trans-LTB4 and w-oxidation products of LTB4. The LTC4 production, by contrast, significantly decreased postoperatively. LTD4 production was observed at neither pre nor postoperative periods. The total amount of LTA4 metabolites at the postoperative period, including LTB4, LTC4, and 6-trans-LTB4, increased 1.2 times compared with that at preoperative period. This indicates the possibility of the alteration of the neutrophil metabolism in 5-lipoxygenase cascade, the increment of LTA4 generation and the change of LTA4 metabolism from LTC4 synthesis to LTB4 generating pathway.

Abdominal Neoplasms↗
PubMed1989

Hageman factor dependent kinin generation system in guinea pig skin: extravascular localization of the components, and prolonged vascular reaction in inhibitor-depleted animal of this system.

1. Monospecific antibodies against components of the guinea pig Hageman factor-dependent system, such as Hageman factor, prekallikrein and high-molecular-weight (HMW) kininogen were prepared. These antibodies demonstrated the presence of all of these components in the normal guinea pig skin extract with the properties identical to them in plasma on western immunoblotting analysis. 2. Guinea pig macroalbumin which is a major circulating inhibitor of activated Hageman factor was immunologically depleted from three animals. Duration of a vascular permeability reaction caused by an intradermal injection of activated Hageman factor was prolonged in all of these guinea pigs approximately twice as long as the control, indicating a presence of negative feedback regulation of the Hageman factor-dependent kinin generation cascade in dermal tissue via the circulating protease inhibitor.

Animals↗
PubMed1989

The major plasma kallikrein inhibitor in guinea pig plasma with contrapsin-like nature.

Kallikrein inhibitor in plasma (KIP) was purified, and the share in the kallikrein inhibitory capacity of guinea pig plasma was estimated by depletion of the inhibitory activity of KIP with anti-KIP IgG. And KIP was characterized the inhibitory activity using various proteases. The purified KIP exhibited a single band on SDS-gel electrophoresis and the molecular weight was 64,000. KIP inhibited plasma kallikrein dose-dependently and time-dependently, forming a complex with kallikrein with the molecular weight of 137,000. Since the kallikrein inhibitory capacity of guinea pig plasma was completely depleted by anti-KIP IgG that inactivated kallikrein inhibitory activity of KIP, KIP was likely to be the major kallikrein inhibitor in guinea pig plasma. KIP inhibited trypsin and elastase, but not chymotrypsin. The Inhibitory spectrum of KIP was different from the spectrum of each protease inhibitor in human plasma, but was similar to the spectrum of contrapsin in mouse plasma. These results indicated that guinea pig plasma had a different mechanism for kallikrein inhibition, compared with human plasma.

Amino Acid Sequence↗
PubMed1989

Complement activation and neutrophil dysfunction in burned patients with sepsis--a study of two cases.

The changes in complement components and neutrophil functions were investigated in two cases of flame burn patients who died of multiple organ failure following septic shock. In the period of bacteremia, complement activation was observed in the plasma of both patients, using an immunoblotting method demonstrating C3a-related antigens. Coincidently, reduced neutrophil function and a decrease in the superoxide and leukotriene producing capacity, were also observed. An in vitro study showed that the capacity to produce superoxide and leukotriene became reduced in normal neutrophils after exposure to complement activated serum. These observations suggested that complement activation, probably brought about by massive bacterial infection, induced the impairment of neutrophil functions and resulted in a further breakdown of the host defence system, thereby leading to sepsis.

Adult↗
PubMed1989

Chemotactic factors for macrophages produced in inflamed skin.

A newly discovered macrophage-chemotactic factor (MCFS-1) was extracted and purified (488-fold) from skin sites of guinea pigs showing delayed hypersensitivity to bovine gamma-globulin. MCFS-1 is a heat-labile glycoprotein with a molecular weight of 150,000, consisting of two polypeptide chains. It has in vivo as well as in vitro chemotactic activity for macrophages and shared 50% of the chemotactic activities for macrophages in the extract. It is produced by limited proteolysis of endogenous trypsin-like protease(s) of plasma precursor protein (Pre-MCFS-1). Enzyme immunohistochemistry reveals that Pre-MCFS-1 is produced in the liver and distributed in the normal skin as a proinflammatory factor. ELISA reveals that the concentrations of the factor are: 140 micrograms/ml in plasma, 7.1 micrograms/ml in inflamed skin extract, and 2.8 micrograms/ml in normal skin extract.

Animals↗
PubMed1989

Depression of prolylendopeptidase activity in the delayed hypersensitive guinea pig skin lesion induced by bovine gamma-globulin.

Prolylendopeptidase activity was increasingly depressed with time from 6 to 24 hr after the start of sensitization in the delayed hypersensitive guinea pig skin lesion induced by bovine gamma-globulin as an antigen. The remarkably depressed activity of the enzyme in the violently inflamed skin began to be restored slowly 48 hr after sensitization, and its activity was ultimately recovered to the original level by 504 hr after a single sensitization in vivo. Depression of the enzymatic activity is caused by a novel prolyendopeptidase inhibitor, whose amino acid composition is 7 Glu, 1 Ser, 2 Gly, 1 Ala, 2 Pro, and 1 Val, generated by inflammation.

Amino Acids↗
PubMed1988

The Hageman factor-dependent system in the vascular permeability reaction.

The mechanism by which the Hageman factor-dependent system induces vascular permeability has been analyzed. The Mr-28,000 active fragment of guinea pig Hageman factor (beta-HFa), injected intradermally, induces an increase in local vascular permeability. Inhibition of vascular permeability resulted from pretreatment of the beta-HFa with immunopurified anti-Hageman factor F(ab')2 antibody at concentrations of 10(-6)-10(-7) M as well as by incubation with corn and pumpkin seed inhibitors of beta-HFa. To determine whether prekallikrein and kallikrein participated in the permeability induced by beta-HFa, circulating prekallikrein was depleted by intra-arterial injections of anti-prekallikrein F(ab')2 antibody. This resulted in about 80% diminution of the vascular permeability response to beta-HFa, without affecting the permeability reaction to bradykinin. Soybean trypsin inhibitor (10(-6) M), injected at the same cutaneous site as the beta-HFa, inhibited the vascular permeability response to beta-HFa by more than 90%. This concentration of soybean inhibitor blocked more than 90% of the activity of guinea pig plasma kallikrein, but did not inhibit the amidolytic capacity of beta-HFa. The permeability activity of beta-HFa (but not its amidolytic activity) was augmented 10-fold by simultaneous injection of a synthetic kinin potentiator, SQ 20,881 (Glu-Tyr-Pro-Arg-Pro-Gln-Ile-Pro-Pro-OH), and was almost completely inhibited by the simultaneous injection of a kinin-destroying enzyme, carboxypeptidase B. These results support the hypothesis that the greatest proportion of vascular permeability induced by beta-HFa is produced by the activation of prekallikrein followed by the release of kinin in the cutaneous tissue. These data offer the first in vivo evidence that the Hageman factor-dependent system by itself can induce inflammatory changes.

Amides↗
PubMed1988

Effect of surgery on neutrophil functions, superoxide and leukotriene production.

Perioperative changes of neutrophil function were investigated in 28 patients who underwent major surgery, particularly focusing on the potential capacity for superoxide and leukotriene production, which seem to be important in host defence. The superoxide-producing capacity of neutrophils, which was examined using N-formyl-peptide or phorbol myristate acetate as an attractant, significantly decreased postoperatively to 55 and 69 per cent of the pre-operative values, respectively. The leukotriene-producing capacity of neutrophils, which was stimulated with calcium ionophore A23187 in the presence of arachidonic acid, significantly changed postoperatively. The leukotriene B4 (LTB4) production increased together with an increment of production of 6-trans 6-trans LTB4, however, increased postoperatively to 1.2 times the (LTC4) production decreased postoperatively. The total production of leukotriene A4 (LTA4) metabolites consisting of LTB4, LTC4, and 6-trans LTB4, however, increased postoperatively to 1.2 times the pre-operative values. This indicates that neutrophils in the postoperative period have a higher capacity for LTA4 production but a lower capacity for superoxide production than those in the pre-operative period.

Adult↗
PubMed1988

Complement conversion and leukocyte kinetics in open heart surgery.

Complement conversions and a pulmonary leukocyte sequestration were observed during cardiopulmonary bypass (CPB) in all of twenty patients who received open heart surgery. A systemic neutropenia was initially observed in the early phase of CPB, and it subsequently turned into a systemic neutrocytosis during the late phase of it. A significant leukocyte sequestration was found in the pulmonary circulation during CPB coincidently with the systemic neutropenia. The contribution of the transpulmonary sequestration to the leukopenia was major, being as high as 80 per cent. Plasma C3, C4, and CH50 levels rapidly decreased following the commencement of CPB. Alterations of the C3 molecule in the patients' plasma were demonstrated using the immunoblotting method. The appearances of C3a and C3b with the apparent molecular weights of 10,000 and 170,000 respectively, might be evidence of the complement activation during CPB. Another type of alteration in the C3 molecule was observed in the generation of a new fragment with the apparent molecular weight of 14,000. The appearance of this fragment, which did not share common epitopes with C3a, might suggest the consumption of complement components during CPB, unrelated to the activation of the complement systems.

Adult↗
PubMed1987

Interstitial-tissue localization of high-molecular-weight kininogen in guinea-pig skin.

A rabbit antibody against the light-chain of guinea-pig high-molecular-weight (HMW) kininogen, which was specific to HWM kininogen and did not recognize low-molecular-weight kininogen, was prepared. This antibody demonstrated the presence of HMW kininogen antigen at the interstitial-tissue space in the guinea-pig skin by means of immunohistochemistry. The interstitial-tissue HMW kininogen antigen was extracted from the skin. This antigen molecule in the skin extract behaved identically as HWM kininogen of plasma in slab-polyacrylamide gel electrophoresis under the presence of sodium dodecyl sulfate followed by immunoblotting. Therefore, it was concluded that HMW kininogen was present in the interstitial-tissue fluid in the skin. The amount of HMW kininogen in the skin extract was quantified by a sandwich enzyme-linked immunosorbent assay with the anti-light-chain antibody and a goat anti-guinea-pig HMW kininogen antibody. On the assumption that the interstitial-tissue volume is 50 ml/100 g wet skin tissue, the average concentration of HMW kininogen in the interstitial-tissue fluid of the skin was calculated to be 23% of the plasma concentration. On the other hand, the proportion of intravascular HMW kininogen (derived from blood remaining in the vessels of the harvested skin) in relation to the total HMW kininogen in the skin extract was quantified by measuring the radio-labelled HMW kininogen which had been injected intravenously as a tracer of the intravascular HMW kininogen. About 5% of the total HMW kininogen in the skin extract was calculated to be derived from the intravascular blood volume of the skin, indicating that the majority of the HMW kininogen in the skin extract was derived from the extravascular-tissue space.

Animals↗
PubMed1987

Determination of lysozyme activity by fluorescence polarization in rheumatoid synovial fluids and release of lysozyme from polymorphonuclear leukocytes by chemotactic factors.

A new method for the measurement of lysozyme activity, which is rapid, quantitative and sensitive, was established and applied to clinical material obtained from arthritis patients. The method is based on fluorescence polarization with the use of fluorescein isothiocyanate-labeled peptidoglycan. Using this method, we found that the synovial fluids obtained from rheumatoid arthritis contained more lysozyme activity than similar samples from osteoarthritis patients (P less than 0.001). Furthermore, we found that chemotactic factors and lysozyme-depleted rheumatoid synovial fluids could induce the release of lysozyme from human polymorphonuclear leukocytes in vitro. It is therefore suggested that lysozyme present in rheumatoid synovial fluids may derive in part from polymorphonuclear leukocytes and the action of chemotactic factor(s) within the fluids.

Arthritis, Rheumatoid↗
PubMed1987

Fifth component of complement (C5)-derived high-molecular-weight macrophage chemotactic factor in normal guinea pig serum.

Normal guinea pig serum contain a chemotactic factor(s) for macrophages. As the chemotactic activity in the serum was absorbed by an anti-C5 antibody affinity column but not by the anti-C3 or anti-macrophage chemotactic factor from skin-1 (MCFS-1) affinity column, the major chemotactic factor in the serum was postulated to be C5-derived. This chemotactic factor, which was a heat-labile molecule with an apparent molecular weight of 150,000 (by gel filtration) and lacked vascular permeability activity, was distinct from the C5a-like anaphylatoxins. Using a combination of a Boyden chamber assay and a morphological polarization assay for the macrophage chemotaxis, it was revealed that this chemotactic factor was latent in plasma and could be activated by incubation for 30 min at 37 degrees C in the presence of a sufficient amount of Ca ion (5 mM) concomitant or not concomitant with the clot formation of the plasma. Precursor of MCFS-1 in plasma was not activated during coagulation.

Animals↗
PubMed1986

A thiol protease of peritoneal macrophages in the guinea pig.

Proteolytic enzymes of the guinea pig peritoneal exudate macrophages were investigated using synthetic fluorogenic peptide substrates. Among several enzymes, t-butyloxycarbonyl-phenylalanyl-seryl-arginine 4-methylcoumaryl-7-amide cleaving enzymes had the highest activity, and the activity in exudate macrophages was about 3 times stronger than that in resident macrophages. The molecular weight of the enzyme was around 35,000 and optimal pH around 6.5-7.0. It was inhibited by thiol-blocking reagents, suggesting a thiol protease.

Animals↗