Cloning of a Novel Babesia equi Gene Encoding a 158-Kilodalton Protein Useful for Serological Diagnosis

In this study, we characterized a Babesia equi Be158 gene obtained by immunoscreening a B. equi cDNA expression phage library with B. equi-infected horse serum. The Be158 gene consists of an open reading frame of 3,510 nucleotides. The recombinant Be158 gene product was produced in Escherichia coli and used for the immunization of mice. In Western blot analysis, mouse immune serum against the Be158 gene product recognized 75- and 158-kDa proteins from the lysate of B. equi-infected erythrocytes. In an indirect fluorescent-antibody test with the mouse immune serum, the Be158 antigen appeared in the cytoplasm of Maltese cross-forming parasites (which consist of four merozoites) and was located mainly in the extraerythrocytic merozoite body. When the recombinant Be158 gene product was used in an enzyme-linked immunosorbent assay as a serological antigen, it was found to react to B. equi-infected horse sera, indicating that the Be158 gene product is useful as a serologically diagnostic antigen for B. equi infection.     

A CASE OF GASTRIC CARCINOMA WITH MASSIVE EOSINOPHILS

This report describes a 67-year-old male with inoperable gastric cancer accompanied by marked tissue and peripheral eosinophilia without evidence of allergic disorders or parasitic infestation. Autopsy revealed an advanced gastric cancer of scirrhous type with metastases to pancreas, bone marrow, ileum, lungs, and lymph nodes. Excessive numbers of mature eosinophils were present in univolved bone marrow, liver and spleen as well as among the signet ring cell component of the cancer in either primary or metastatic sites. The primary cancer also possessed a component of tubular adenocarcinoma which was associated with only a few eosinophils. Hence, we speculate that an eosinophil mobilizing (chemotactic and/or proliferating) factor (s) was produced by the signet ring cancer cells.     

Protective effect of recombinant neutrophil elastase inhibitor (R-020) on sepsis-induced organ injury in rat

Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and punctureinduced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.     

IL-1 is required for allergen-specific Th2 cell activation and the development of airway hypersensitivity response

IL-1 is a pro-inflammatory cytokine consisted of two molecular species, IL-1alpha and IL-1beta, and the IL-1 receptor antagonist (IL-1Ra) is a natural inhibitor of both molecules. Although it is suggested that IL-1 potentiates immune responses mediated by T(h)2 cells, the role of IL-1 in asthma still remains unclear. In this study, we demonstrate that the ovalbumin (OVA)-induced airway hypersensitivity response (AHR) in IL-1alpha/beta-deficient (IL-1alpha/beta(-/-)) mice was significantly reduced from the levels seen in wild-type mice, whereas the responses seen in IL-1Ra(-/-) mice were profoundly exacerbated, suggesting that IL-1 is required for T(h)2 cell activation during AHR. OVA-specific T cell proliferation, IL-4 and IL-5 production by T cells, and IgG1 and IgE production by B cells in IL-1alpha/beta(-/-) mice were markedly reduced compared with these responses in wild-type mice; such responses were enhanced in IL-1Ra(-/-) mice. Using IL-1alpha(-/-) and IL-1beta(-/-) mice, we determined that both IL-1alpha and IL-1beta are involved in this reaction. Both IgG1 and IgE levels were reduced in IL-1beta(-/-) mice, while only IgE levels were affected in IL-1alpha(-/-) mice, indicating a functional difference between IL-1alpha and IL-1beta. These observations indicate that IL-1 plays important roles in the development of AHR.     

Immunohistochemical study on tissue transglutaminase and copper-zinc superoxide dismutase in human myocardium: Its relevance to apoptosis detected by the nick end labelling method

The influence of free radicals on apoptosis was studied in the human heart; 45 autopsy cases were examined by the nick end labelling method (NELM) that detects DNA fragmentation. Immunostaining for copper-zinc superoxide dismutase (CuZn-SOD) and tissue transglutaminase (tTG) induced frequently during apoptosis were also studied. Positive immunoreaction for tTG was detected in mucinous degeneration of myocardial cells; these same cells were also positive for CuZn-SOD but negative for NELM. Myocardial cells showing basophilic alterations after haematoxylin and eosin staining were also positive for CuZn-SOD but negative for the other markers examined. Positive nuclear reaction by NELM was only observed in myocardial cells showing contraction band necrosis or irregularly shaped nuclei surrounding recent or long-standing infarcted foci. In these the other two markers were negative. Since mucinous degeneration lacks the distinguishing morphological features of apoptosis, immunoreactive tTG in this lesion may not imply that the cells are undergoing apoptosis. tTG can be induced in non-apoptotic conditions and may not be involved in apoptosis induced by infarction. Histological disassociation between CuZn-SOD expression and apoptosis suggests the possibility of a cytoprotective role played by endogenous CuZn-SOD against free radical generation in the human heart.