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To investigate chronic immune effects of polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF), in vitro lymphocyte transformation in response to phytohemagglutinin (PHA) and concanavalin A (Con A) was studied in 139 patients with Yusho and 61 controls. PHA-induced lymphocyte transformation was significantly lower in patients with Yusho than in controls. PHA-induced lymphocyte transformation was inversely correlated with the concentrations of PCB and 2,3,4,7, 8-pentachlorodibenzofuran (PeCDF) in the blood. Con A-induced lymphocyte transformation showed similar inverse correlations with the concentrations of PCB and 2,3,4,7, 8-PeCDF. We conclude that impairment of mitogen-induced lymphocyte transformation in patients with Yusho may be associated with PCB and 2,3,4,7,8-PeCDF in the blood.

Three isopeptides of endothelin (ET-1, -2, and -3) exert various actions through stimulation of two sub-types of receptor (ETA and ETB). Vascular endothelial cells produce only ET-1. In addition to its powerful vasoconstrictor action, ET-1 has direct mitogenic actions on cardiovascular tissues, as well as comitogennic actions with a wide variety of growth factors and vasoactive substances. ET-1 also promotes the synthesis and secretion of growth factors and various substances, including extracellular constituents. These effects of endogenous ET-1 would naturally be thought to be concerned with the development and/or aggravation of chronic cardiovascular diseases; e.g., hypertension, pulmonary hypertension, vascular remodeling (stenosis, atherosclerosis), renal failure, and heart failure. A large number of peptide and orally active non-peptide endothelin receptor antagonists have been developed, and utilized to analyze physiological and pathophysiological roles of endogenous ET-1. These antagonists have been shown to exert excellent therapeutic effects in animal models of various kinds of diseases by either acute or chronic treatment. Therapeutic treatment of patients suffering from the above-mentioned cardiovascular diseases with ET-receptor antagonists have also been taking place, and bosentan (ETA/ETB antagonist) was recently approved by the FDA as a formal therapeutic drug for pulmonary hypertension. In this review, perspectives for therapeutic applicability of ET-receptor antagonists will be explored.

An HGF antagonist, NK4, inhibits not only invasion and metastasis of tumor cells driven by HGF-Met receptor binding, but also tumor angiogenesis. To address the antitumor activities of NK4, we investigated the biological behaviors of CT26 transfected with the NK4 gene (CT26-NK4) in vitro and in vivo. In the in vitro assay, the invasion in MOCK transfected cells (control) was stimulated by HGF; however, in CT26-NK4 cells, these effects were completely inhibited. In the in vivo assay, the tumor growth of CT26-NK4 was strongly suppressed and the survival of CT26-NK4 tumor-bearing mice was significantly prolonged. Immunohistochemical analysis revealed that while proliferating cells (PCNA immunostaining) of CT26-NK4 tumors were weakly suppressed, the micro-vessel number (CD31/PECAM-1 immunostaining) in those tumors was significantly suppressed as compared with the control tumors. In conclusion, NK4 exerts potent antitumor effects via anti-angiogenesis rather than inhibition of biological events of tumor cells stimulated by HGF.

Hepatocyte growth factor (HGF) is the most potent mitogen of mature hepatocytes in primary culture, and is a molecule composed of 69 kD alpha-chain and 34 kD beta-chain. HGF predominantly acts on various epithelial cells as a mitogen, motogen and a morphogen. HGF mRNA and HGF protein increases rapidly in the liver and plasma of rats with liver injury such as hepatitis, ischemia, physical crush and partial hepatectomy. Production of HGF in the liver occurs in Kupffer cells, sinusoidal endothelial cells, and Ito cells, but not in hepatocytes. HGF mRNA is also rapidly increased in the intact organs such as lung, kidney and spleen. Thus, HGF may act as a hepatotrophic factor for liver regeneration through two mechanisms: a paracrine mechanism and an endocrine mechanism. Moreover, intravenously injected HGF enhances liver regeneration and protects hepatitis in vivo. Consequently, HGF may prove to be useful for the clinical treatment of patients with liver disease. Recently, we found a factor which specially appears in the blood of rats with organ injury and increases the synthesis of HGF, and it was named "injurin". IL-1 alpha and IL-1 beta are also positive regulators for the expression of the HGF gene, while TGF-beta and Dexamethazone down-regulate HGF expression.

The purpose of this study is to develop an assay system for quantification of bFGF in human tissue and to investigate the changes in bFGF content in the human placenta during pregnancy. Sixty-two placental tissue samples from various stages of normal pregnancies were collected. Approximately 28 micrograms bFGF was obtained per 1 kg of placental tissue. The recovery rates were 17.1 +/- 7.4%. The purified samples were confirmed as bFGF by SDS-PAGE and enzyme-linked immunoelectrotransfer blot (EITB) with anti-human bFGF monoclonal antibody. The bFGF readings in the human placenta determined by RIA were 11.81 +/- 2.11 fmol/mg protein (first trimester), 20.45 +/- 4.85 (early second trimester), 9.52 +/- 5.02 (late second trimester), 7.41 +/- 2.07 (third trimester), and 7.75 +/- 1.86 (post trimester). The placental bFGF were significantly high in the early stage of second trimester and declined gradually during the remainder of the pregnancy. The RIA values were correlated closely with the values obtained by bioassay. These results demonstrate that our assay system provides a tool for the quantification of bFGF in biological samples and suggest that bFGF, the active mitogen and angiogenic factor, participates in the formation of the human placenta.

The chemical structure and immunobiological activities of the cell wall peptidoglycan isolated from Capnocytophaga species was investigated. Peptidoglycan was isolated from Capnocytophaga species strain SE2-2 by boiling in 4% sodium dodecyl sulfate and by digestion with pronase, trypsin and alpha-amylase. Analysis of amino acids and amino sugars of the peptidoglycan revealed that glucosamine, muramic acid, D-glutamic acid, alanine, and diaminopimelic acid (A2pm) were the principal components. Serine and glycine were not found. Dinitrophenylation method revealed that about half of A2pm residue had a free amino group, and analysis by hydrazinolysis showed that a small part of alanine and A2pm located at the C-terminal. The above results indicate that one of the amino groups of A2pm residue at one strand of the stem peptide subunit cross-linked to the carboxyl group of alanine of the neighboring strand. It was thus revealed that the peptidoglycan of Capnocytophaga species belonged to the Al gamma type of the classification by Schleifer and Kandler. Peptidoglycan isolated from Capnocytophaga species strain SE2-2 was found to be definitely adjuvant-active in induction of delayed type hypersensitivity against ovalbumin when administered to guinea pigs as water-in-oil emulsion and in stimulation of increase serum antibody levels. Regarding mitogenicity on splenocytes of BALB/c and BALB/c nu/nu mice, peptidoglycan from Capnocytophaga species was markedly enhanced the uptake [3H] thymidine in dose of 10 micrograms/10(5) cells, however thymocytes were not reactive. Stimulation effects on peritoneal macrophages from a guinea pig to incorporation of 14C-glucosamin was exhibited by addition of 100 micrograms of this peptidoglycan. These findings indicate that peptidoglycan of Capnocytophaga species might eventually be responsible for destruction of periodontal tissue by host mediated activities.

The primary etiological agent of all periapical lesions has long been considered to be bacterial. Furthermore, bacteria from infected root canals are potential antigens capable of initiating immunological reactions in periapical tissues. The purpose of this study, therefore, was clarify the immunological potentials of Veillonella parvula (V. parvula), which was frequently isolated from root canals with periapical lesion. Immunobiological activities of V. parvula sonic extracts were investigated on the enhancement of monocytes migration, induction of interleukin-1 (IL-1) production, mitogenicity and polyclonal activation of B cell. Following results were obtained: 1. Both LPS and protein of V. parvula sonic extracts strongly enhanced the activity of human peripheral monocytes migration. 2. Induction of IL-1 on C3H/HeN mice macrophage by V. parvula sonic extracts were stronger than that of S. typhimurium LPS as positive control. 3. It was found that mitogenicity of LPS from V. parvula on splenocytes was stronger than that of the protein, however mitogenicity on thymocytes was not shown in both preparation. 4. The polyclonal activation of B cell on splenocytes of BALB/c nu/nu mice by V. parvula was induced by the protein and LPS. 5. These findings indicate that both the protein and LPS from V. parvula have a regulation of immunobiological responses against macrophages and lymphocytes.