Synthesis and application of hepatitis E virus peptides to diagnosis

Based on computer analysis of hydrophobicity and prediction of secondary structures for the full-length putative proteins encoded by open reading frame-1 (ORF-1), ORF-2 and ORF-3 of hepatitis E virus (HEV), we selected antigenic regions with hydrophilicity, beta-turn, and beta-sheet, and synthesized 7 peptides of possible epitope-containing regions of the polypeptide encoded by all 3 ORFs of HEV genomic RNA by Merrifield's method of solid-phase synthesis. The synthetic peptides were screened and identified by solid-phase enzyme-linked immunosorbent assay (ELISA). Three of the peptides (EH174 from ORF-1, EH286 from ORF-2 and EH362 from ORF-3) showed antigenic activity and possible application for the development of anti-HEV test kits (the peptide-based ELISA). The laboratory experiments and clinical trials showed that the kits, using a set of 3 synthetic HEV peptides as coating antigens, were of high specificity and exhibited good reproducibility. The small-scale seroepidemiological survey indicated high seroprevalence (14.3%) of anti-HEV in Tibetan populations. Additionally, the results also demonstrated good agreement with clinical findings, suggesting that the test kits will be of major use for immunodiagnosis and seroepidemiological surveys of HEV infection.

Administration of anti-CD4 monoclonal antibody with intrathymic injection of alloantigen results in rat cardiac allograft tolerance

BACKGROUND

We have previously reported the induction of donor-specific tolerance to cardiac allografts after intrathymic injection of alloantigen with simultaneous administration of antilymphocyte serum treatment to eliminate peripheral T cells. The present study determines whether prolongation of a fully major histocompatibility complex-mismatched cardiac allograft is achieved after a single administration of anti-CD4 monoclonal antibody (MoAb) combined with intrathymic injection of alloantigen.

METHODS

Male Buffalo rats were given Lewis splenocytes via the intrathymic or intravenous route in combination with a single administration of anti-CD4 monoclonal antibody (OX-38) or anti-CD8 MoAb (OX-8) or both. Heterotopic cardiac transplantation was performed 21 days after intrathymic alloantigen or MoAb pretreatment or both. Fluorescence-activated cell sorter analysis determined changes in lymphocyte compartment T-cell subsets, and in vitro studies examined recipient cellular reactivity.

RESULTS

By 21 days after anti-CD4 MoAb treatment earlier nonspecific immunosuppression had resolved with 80% recovery of peripheral CD4+ T cells and restoration of recipient immunocompetence to allow normal rejection of a cardiac allograft. Combined treatment with intrathymic, but not intravenous, alloantigen plus anti-CD4 MoAb induced donor-specific tolerance to subsequent rat cardiac allografts. However, anti-CD8 MoAb combined with intrathymic alloantigen failed to induce tolerance despite a profound depletion of the CD8+ T-cell subset.

CONCLUSIONS

Combined treatment of rats with intrathymic donor alloantigen and a single administration of anti-CD4, but not anti-CD8, MoAb significantly prolongs cardiac allograft survival across a fully major histocompatibility complex mismatched strain combination.

Inhibition of constitutive nitric oxide synthase in the brain by pentamidine, a calmodulin antagonist

Nitric oxide (NO) which is produced by activation of Ca2+/calmodulin-dependent NO synthase is known to induce neuronal damage. We examined the effects of 3'-azido-2',3'-dideoxythymidine (AZT, a reverse transcriptase inhibitor), pentamidine (a therapeutic drug for Pneumocystis carinii pneumonia) and calmodulin antagonists such as trifluoperazine and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) on NO synthase activation. Although AZT had no effect on the activity of constitutive neuronal NO synthase, pentamidine inhibited the activation of neuronal NO synthase as did trifluoperazine and W-7. The inhibition by pentamidine was prevented by the addition of purified calmodulin. In addition, pentamidine inhibited calmodulin-dependent activation of neuronal NO synthase purified from rat cerebellum. From these results, it is suggested that pentamidine inhibits the neuronal NO synthase activation by probably acting as a calmodulin antagonist.

Prevalence of nonthyroid specific autoantibodies in autoimmune thyroid diseases

To clarify the involvement of polyclonal activation of autoimmune reaction in organ-specific autoimmune diseases, we investigated the prevalence of nonthyroid specific autoantibodies in 50 patients with autoimmune thyroid diseases (22 patients with Graves' disease and 28 with Hashimoto's disease) and in 50 age- and sex-matched controls. None of the 100 subjects had any clinical manifestations or laboratory data indicating any other immunological, infectious, hepatic, or malignant diseases. The prevalence of positive antibodies to nucleus, smooth muscle, and single-stranded DNA in the patients (26%, 36%, and 34%, respectively) was higher than that in the control group (8%, 4%, and 4%, respectively), although neither group was positive for autoantibodies against double-stranded DNA, extractable nuclear antigen, SS-A, SS-B, mitochondria, or rheumatoid factor. Furthermore, 66% of the patients had at least one autoantibody to nucleus, smooth muscle, or single-stranded DNA. In conclusion, patients with autoimmune thyroid diseases show high prevalence of autoantibody against not only thyroid-specific, but also nonthyroid-specific antigens. These results are consistent with the concept that immune reaction of patients with organ-specific autoimmune diseases may be polyclonally accelerated to the production of antibodies against both organ and nonorgan specific autoantigens.

Secondary amyloidosis with severe autonomic dysfunctions

A 46-year-old male underwent hemodialysis because of progressed glomerulo-nephritis. Since he suffered from severe diarrhea during the course of the illness, both gastric and colon biopsies were performed. Significant amyloid deposition was recognized in the submucosal layer of these specimen. This amyloid was positive for anti-AA-protein antibody staining and soluble in KMnO4 solution, indicating secondary induced amyloid. Despite of absence of orthostatic hypotension, examinations revealed extreme reduction in tears and salivary secretion, anhidrosis, a decrease in the coefficiency of variation of the cardiographic R-R interval, and a decrease in the accumulation of [123I]meta-iodobenzylguanidine (MIBG) in the heart, suggesting that severe glandular and visceral autonomic dysfunctions had occurred in the patient.

Pretransplant intrathymic inoculation of donor antigen combined with FK506 treatment: prolongation of survival of cardiac, but not renal, allografts in rats

It has been shown that pretransplant intrathymic injection of donor antigen prolongs rat cardiac allograft survival. The purpose of the present study was to evaluate whether co-administration of FK506 could enhance the beneficial effect of intrathymic preimmunization; we also wished to clarify whether this combined treatment could be effective for renal allografts. Seven days prior to transplantation 5 x 10(7) donor splenocytes were injected into the thymus of LEW (RT1l) recipients of WKA (RT1u) cardiac or renal allografts. Using a miniosmotic pump, FK506 was administered for 7 days before transplantation at a dose of 3 mg/kg/day. Whereas intrathymic injection of donor splenocytes or subcutaneous FK506 alone showed limited (15.2 days) or no (7.3 days) prolongation of cardiac allograft survival, the combined treatment with these two modalities synergistically prolonged the survival of the cardiac allograft (> 82.0 days). This combined treatment, however, failed to prolong renal allograft survival (8.4 days). Although donor-specific prolongation of a second cardiac allograft was obtained in LEW rats with a well beating WKA heart, two of the three recipients ultimately rejected both first and second WKA cardiac allografts. Additionally, LEW rats with a long-surviving WKA heart rejected a WKA renal allograft in a normal fashion. These data demonstrate a synergistic effect of intrathymic injection of donor splenocytes and subcutaneous FK506 on cardiac, but not renal, allograft survival and suggest that quantitative or qualitative differences of immunogenicity of kidney may contribute to the rejection of renal allografts.

Inhibitory effects of pentamidine on N-methyl-D-aspartate (NMDA) receptor/channels in the rat brain

Effects of pentamidine, a therapeutic drug for Pneumocystis carinii pneumonia (PCP) in acquired immunodeficiency syndrome (AIDS), on specific bindings of [3H](+)-5-methyl-10,11-dihydro-5H- dibenzo[a,d]cyclohepten-5,11-imine maleate (MK-801) and [3H]nitrendipine were investigated in crude synaptic membranes (CSM) of rat brain. Pentamidine inhibited [3H]MK-801 binding but did not change [3H]nitrendipine binding, although neither binding was inhibited by 3'-azido-2',3'-dideoxythymidine or 2',3'-dideoxycytidine (inhibitors for reverse transcriptase of HIV-1), or FK-506 or cyclosporin A (immunosuppressants). In Triton X-100-treated CSM (post-synaptic density-rich fractions), the inhibitory effect of pentamidine on [3H]MK-801 binding was partially prevented by addition of spermine and NMDA plus glycine (Gly). Electrophysiological experiments showed that pentamidine also inhibited Ca(2+)-current evoked by NMDA plus Gly in Xenopus oocytes injected with rat brain mRNA. These results suggest that pentamidine is a potent inhibitor for NMDA receptor/channels.

The progressive degeneration of interlobular bile ducts in biliary atresia: an ultrastructural study

The ultrastructure of the interlobular bile ducts were observed in hepatic specimens obtained at surgery in ten patients with biliary atresia, in order to investigate the progress of their degeneration over time after the onset of the disease. As an index for the passage of time, the degree of fibrosis in the portal tracts was investigated. Then the ultrastructural features in the interlobular bile ducts were contrasted with the grading of portal fibrosis Generally, the ultrastructural changes of the interlobular bile ducts were more marked in the cases with severe portal fibrosis than that observed in the cases with mild fibrosis. This correlation suggests that the degeneration of the interlobular bile ducts progressively worsens over time after the obliteration of the extrahepatic bile duct.

Properties of highly cross-linked autopolymerizing reline acrylic resins

Transverse bend strength tests and water sorption and solubility tests were done to compare the properties of highly cross-linked autopolymerizing reline resin with those of conventional non-cross-linked autopolymerizing reline resins. The relationship between composition and properties of autopolymerizing reline resins was also investigated. Highly cross-linked reline resins and the one that contained mainly poly(methyl methacrylate) and methyl methacrylate had a higher transverse bend strength and modulus of elasticity than the other reline resins (p < 0.01). The highly cross-linked reline resins also had significantly lower water sorption than the other reline resins (p < 0.01). Reline resins, except for one, had significantly higher solubility than heat-polymerizing denture base acrylic resins (p < 0.01).

Effect of Clostridium perfringens-derived wound healing substance as compared with epidermal growth factor on the growth and morphological transformation of BALB/3T3 A31-1-1 cells

Clostridium perfringens-derived wound-healing substance (WHS), having growth-stimulating activity, was examined to determine its effect on the growth and morphological transformation of BALB/3T3 A31-1-1 cells. WHS accelerated the cell growth at the exponential growth phase, shortening the doubling time by 8-18%. The maximum cell density of the treated cultures was slightly higher than that of the control culture, and the cell number decreased in the same way as the control cells did. On the other hand, the cells treated with epidermal growth factor (EGF) or insulin showed growth rates similar to that of the control cells during the exponential growth phase, and after the control cells attained the maximum cell number, the number of the treated cells continued to increase gradually for more than 4 days and then decreased. Under the experimental conditions of the two-stage transformation assay, application of WHS at the tumor-initiation or promotion stage did not accelerate the formation of transformed foci. Although treatment with EGF at the initiation stage induced no enhancement, marked enhancement of morphological transformation was observed in the treatment at the promotion stage. These results indicate that the mode of action between WHS and EGF or insulin is different on the growth-stimulating activity and morphological transformation of BALB/3T3 A31-1-1 cells.

Expression of hepatocyte growth factor in normal and carbon tetrachloride-treated monkeys

We examined hepatocyte growth factor-producing organs in normal and carbon tetrachloride-treated Japanese monkeys, a species more related to human beings than rats, by measuring hepatocyte growth factor protein and hepatocyte growth factor mRNA in various tissues. Hepatocyte growth factor protein and hepatocyte growth factor mRNA levels were determined by use of an enzyme-linked immunosorbent assay for human hepatocyte growth factor and Northern-blot analysis using human hepatocyte growth factor cDNA as a probe, respectively. Although very slight amounts of hepatocyte growth factor protein were found in various organs of normal monkeys, the hepatocyte growth factor protein levels were remarkably increased only in the livers and spleens of carbon tetrachloride-treated monkeys. Hepatocyte growth factor mRNA was distinctly detected in the livers, spleens, lungs, intestinal tracts, adrenal glands and aortas of normal monkeys. After the administration of carbon tetrachloride, the hepatocyte growth factor mRNA levels in the liver, spleen and gastrointestinal tract were markedly increased; the level in the lung was unchanged, differing from the findings in rats; and the levels in adrenal gland and aorta were unaltered. These results indicate that the liver is an important hepatocyte growth factor-producing organ in monkeys during liver regeneration and that hepatocyte growth factor induced in the liver may stimulate hepatocyte proliferation by way of a paracrine mode.

Identification of nucleolin as a binding protein for midkine (MK) and heparin-binding growth associated molecule (HB-GAM)

Midkine (MK) is a heparin-binding growth/differentiation factor with a molecular weight of 13 kDa, and is structurally unrelated to fibroblast growth factors (FGF). We studied MK-binding proteins in order to clarify the action mechanism of MK. A 100-kDa protein was identified in PYS-2, 3T3, and L cells as an MK-binding protein by a ligand blot experiment. This MK-binding protein was purified by affinity chromatography on an MK-agarose column followed by SDS polyacrylamide gel electrophoresis. Sequence determination of N-terminal 23 amino acid residues revealed that the MK-binding protein was nucleolin, a major nucleolar protein, which functions as a shuttle protein between the nucleus and cytoplasm and is located also on the cell surface. Heparin-binding growth associated molecule (HB-GAM), which has 50% sequence identity with MK, fused to maltose-binding protein also bound to nucleolin. On the other hand, basic FGF (bFGF) scarcely bound to nucleolin in the absence of heparin, while both MK and bFGF bound weakly to nucleolin in the presence of heparin. Nuclear localization of MK was shown in hemangioma cells by immunohistochemical staining. These findings supported the hypothesis that parts of the MK and HB-GAM are translocated to the nucleus after binding with nucleolin.

Hepatitis C virus RNA and anti-N14 antibody levels during interferon alpha therapy for chronic hepatitis C

To investigate the markers useful for evaluating the long-term efficacy of interferon (IFN) therapy, the quantity of hepatitis C virus (HCV) RNA and two anti-HCV antibody titers (anti-N14 and anti-C-100-3 antibody) in 21 chronic hepatitis C patients were determined. In all complete responders, a sustained clearance of the virus and reductions in the anti-HCV antibody titers were observed during and after therapy. In most of the temporary responders, reductions in the HCV RNA levels and in both anti-HCV antibody titers were observed temporarily during the therapy, and relapse followed. In nonresponders, although the HCV RNA levels and anti-N14 antibody titer tended to remain unchanged or increased during and after therapy, the anti-C-100-3 antibody titers showed no tendency. These results demonstrate that the monitoring of the HCV RNA level and anti-N14 antibody titer is clinically useful for following the patient's response to IFN therapy for chronic hepatitis C.

Infective endocarditis caused by an indigenous bacterium (Gemella morbillorum)

A case of infective endocarditis (IE) caused by a rare pathogen, Gemella morbillorum, is presented. Because of persistent low-grade fever after dental treatment, the patient was given oral antibiotics. Whereas he was diagnosed as having aortic regurgitation by a cardiologist, and IE was not suggested unfortunately. After long-term chemotherapy over five months, he was aware of nocturnal dyspnea and Gemella morbillorum was detected by blood culture. Then, he was treated with intravenous administration of Penicillin-G, and underwent surgical operation for valve replacement. No cases of IE due to this organism have been reported in Japan.

Monoclonal antibody HML-1 reactivity with adult T-cell leukaemia/lymphoma and other lymphomas

Human T-cell leukaemia/lymphoma virus type 1 (HTLV-1), a causative virus of adult T-cell leukaemia/lymphoma (ATLL), is known to be transmitted by breast-feeding. Using a monoclonal antibody HML-1 which labels human intestinal intra-epithelial T lymphocytes, we have immunohistochemically examined ATLL tissues in order to evaluate the possibility that HTLV-1 infected intestinal T cells are the origin of ATLL cells. Previously this antibody was reported to react with intestinal T-cell malignant lymphomas but not with peripheral tumours, or any B-cell lymphomas. We investigated 181 patients with malignant lymphomas and found that 19 out of 113 ATLLs were positive for HML-1. T-cell malignant lymphomas excluding ATLL also reacted with HML-1 (7/24), but all the B-cell lymphomas 0/33) and non-neoplastic lymph node and skin lesions (0/10) were negative for HML-1. In patients with ATLL and other T-cell malignant lymphomas, the positivity level of HML-1 was relatively higher in stomach (3/7) and tonsil (2/6) than that in lymph nodes (15/100) and skin (8/47). We observed one HML-1 positive ATLL patient with tumour formation in the skin and lymphadenopathy and marked infiltration of the large intestine but minimal involvement of other organs. Although HML-1 was frequently expressed in gastric infiltration of ATLL, the level of positivity was too low in lymph nodes to support the hypothesis that HTLV-1 infected intestinal T cells are the origin of ATLL cells.(ABSTRACT TRUNCATED AT 250 WORDS)