Recent advances in echocardiographic diagnosis of ischemic heart disease

Before the early 1990s, the diagnostic usefulness of echocardiography for ischemic heart disease had been relatively limited compared with that for other cardiac diseases such as valvular disease, congenital anomalies and cardiomyopathies. The principal role of echocardiography was to assess persistent regional wall motion abnormality as well as to detect complications of myocardial infarction. However, recent technological advances have created many newer applications of echocardiography in this field. One of the most important advances was seen in the field of stress echocardiography. Dobutamine stress echocardiography has become an established method of diagnosing transient myocardial ischemia due to coronary stenosis and assessing the myocardial viability of a persistently akinetic segment. More recently, several new contrast agents have been developed or will be available in the near future to visualize the blood stream within the left heart cavity and myocardial blood flow. Simultaneously, new ultrasound technologies including harmonic imaging and gated intermittent imaging have enhanced the selective visualization of contrast agents and will contribute to noninvasive imaging of coronary microcirculation. Harmonic imaging has also been shown to improve quality of B-mode image without a contrast agent and will play an important role in the clinical recognition of wall motion abnormality in patients with ischemic heart disease. Recent advances in three-dimensional technology have enabled accurate measurements of left ventricular volume and ejection fraction without any geometrical assumption, which may be especially important for the evaluation of ischemic patients who often have a deformed left ventricular cavity due to remodeling.     

Lyotropic mesophase of imogolite, 1. Effect of polydispersity on phase diagram

The acidic aqueous solution of imogolite is proposed to be an ideal lyotropic system. No temperature dependence was marked on the two phase boundary concentrations (A and B points) of imogolite solutions as predicted by the theories of Flory and Onsager. A satisfactory quantitative agreement was observed with Onsager's theory. The polydispersity of rod lengths was found to shift the A point towards lower concentrations than expected from theory.     

Further development of a recombinant feline herpesvirus type 1 expressing the Gag protein of feline immunodeficiency virus

Summary.  We have previously reported the construction of a recombinant feline herpesvirus type 1 (FHV-1), designated C7301ddlTK-gag, expressing the Gag precursor protein of feline immunodeficiency virus (FIV). In this study, we report the construction of a further recombinant FHV-1 (ddlTK(gBp)-gag) which carries an FHV-1 gB promoter sequence upstream of the FIV gag gene of C7301ddlTK-gag. Strong expression of the FIV Gag protein by ddlTK(gBp)-gag was confirmed by immunoblot analyses and enzyme-linked immunosorbent assays. Although C7301ddlTK-gag and ddlTK(gBp)-gag failed to induce anti-FIV Gag antibodies in cats, we confirmed the infectivity and stability of these recombinants in cats. Received January 14, 2000 Accepted August 4, 2000     

Expression of canine interferon-gamma by a recombinant vaccinia virus and its antiviral effect

A recombinant vaccinia virus-expressing canine interferon (IFN)-gamma (vv/cIFN-gamma) was constructed. In rabbit kidney (RK13) and canine A72 cells infected with vv/cIFN-gamma, IFN activity was detected in the culture supernatants of both cell types. Canine IFN-gamma was also detected in both cell extracts by Western blot. The activity of the recombinant canine IFN-gamma in RK13 cells was higher than that in A72 cells. The vv/cIFN-gamma could not grow in A72 cells at a low multiplicity of infection, probably due to the antiviral activity of the canine IFN-gamma produced. Although exogenous IFN-gamma did not inhibit the growth of vaccinia virus, addition of anti-canine IFN-gamma serum recovered the growth of the vv/cIFN-gamma on A72 cells in a dose-dependent manner. These results suggest that the growth of vv/cIFN-gamma was inhibited by IFN-gamma produced in a paracrine and autocrine manner. In addition, the recombinant canine IFN-gamma inhibited the multiplication of canine herpesvirus, pseudorabies virus and canine adenovirus type 1 in Madin-Darby canine kidney cells. The antiviral effect of canine IFN-gamma was more effective than that of canine IFN-beta. From the present studies, we concluded the recombinant virus may be a useful suicide viral vector.     

Immunohistochemistry and angiography in adenomatous hyperplasia and small hepatocellular carcinomas

The sinusoidal structure and blood supply of 38 liver nodules less than 2 cm In diameter were Investigated. There were 18 cases of adenomatous hyperplasia (AH) and 20 cases of hepatocetlular carcinoma (HCC). Growth pattern, encapsulation and vascularity were examined, and Immunohistochemistry performed for factor VIII related antigen (factor VIII), type IV collagen (collagen IV), lamlnln and CD68. There were significant differences between AH and small HCC, except for the expression of CD68. There were differences In tumor size, vasculartty and the components of the basement membrane between AH and small, well differentiated HCC. The cases of AH were supplied by the portal system and maintained the sinusoidal structure, but small well-differentiated HCC were supplied by a mixture of portal and arterial vessels. In spite of their small size, moderately and poorly differentiated HCC had capillary and were supplied by branches of the hepatic artery.     

Induction of lymphosarcoma in sheep inoculated with bovine leukaemia virus

Five sheep were experimentally inoculated with BLV in order to study the humoral immune response in animals infected with bovine leukaemia virus (BLV). During experimental periods of 46 months, 2 sheep died with leukaemia and one sheep showed splenomegaly and proliferation of tumour cells. The other 2 sheep were clinically normal. All of the inoculated sheep developed antiviral antibodies 1 month after inoculation and BLV could be re-isolated in lymphocytes 2 to 3 months after inoculation. Antibody against glycoprotein antigen (gp51) of BLV appeared earlier than the antibody against protein antigen (p24) and antibody titres of the former were higher than those of the latter during the course of the experiment. The complement dependent antibody cytotoxicity test was performed for the detection of antibody against BLV-related cell membrane antigen with 2 different kinds of target cells; FLK cells which are foetal lamb kidney cells chronically infected with BLV and SF-28 cells which are sheep fibroblasts transformed with BLV in vitro. All 5 sheep developed cytotoxic antibodies against both types of cells. In sera from two leukaemic sheep, cytotoxic antibody titres against SF-28 cells gradually decreased 30 months after inoculation and finally became negative one to 3 months before they died of leukaemia. However, these leukaemic sheep persistently produced antibodies against gp51 and p24.     

Immune responses of interferon gamma (IFN-gamma) knock out mice to repeated Haemaphysalis longicornis (Acari: Ixodidae) nymph infestations

To investigate the immunological mechanisms of acquired resistance to tick infestation, interferon gamma (IFN-gamma) deficient mice (IFN-gamma mice) were used to assess interleukin-4 (IL-4) and antibody production levels against tick salivary gland antigen on three successive infestations with Haemoaphysalis longicornis Neumann nymphs. The engorged body weight of the ticks decreased during the second and third infestations. Similar observations were noted in IFN-gamma+/+ mice. However, the engorged body weight of the ticks from IFN-gamma +/+ mice were considerably lower than those from IFN-gamma-/- mice. A marked increase in antibody production during the second and third infestations was observed indicating that IFN-gamma-/- mice could acquire immunological resistance against H. longicornis nymphs. Moreover, IL-4 levels were higher during the first and third infestations but decreased during the second infestation. IL-4 levels were significantly higher in IFN-gamma-/- mice than in IFN-gamma+/+ mice. We have shown here that the statistically significant high IL-4 levels observed in IFN-gamma-/- mice may be a result of type 2 helper cell (Th2) polarization. However, the apparently higher IL-4 levels during the first and third infestations and the notable decline during the second infestation suggest that other cytokines or factors in the host immune system may play a part in regulating IL-4 levels.     

Granuloma associated with Trichosporon asahii infection in the lung: Unusual pathological findings and PCR detection of Trichosporon DNA.

We describe the first case of a Trichosporon asahii infection of the lung characterized by an epithelioid granuloma with multinucleated giant cells. The patient died of respiratory failure due to lung fibrosis and lung cancer. Autopsy showed primary lung cancer with metastasis, lung fibrosis, and a focal infectious lesion containing the filamentous and yeast forms of a fungus. From its shape the fungus was judged to be Trichosporon, but unusual pathological findings revealed an epithelioid granuloma with multinucleated giant cells surrounding the hyphae and yeast cells. Immunohistochemical staining was performed using the specific Trichosporon spp. monoclonal antibodies and DNA identificationn was done by the PCR. The results showed this case to be a localized Trichosporon asahii infection. Hypersensitivity pneumonitis (HP) due to Trichosporon spp. with its pathological finding of inflammation with granuloma is common, but infections with granulomatous inflammation are extremely rare. This case suggests that Trichosporon infection may develop into granuloma with multinucleated giant cells.     

Cloning of a truncated Babesia equi gene encoding an 82-kilodalton protein and its potential use in an enzyme-linked immunosorbent assay

To isolate Babesia equi genes encoding immunodominant proteins, a cDNA expression library prepared from B. equi mRNA was immunoscreened with B. equi-infected horse serum. Eighteen positive cDNA clones were obtained, and the clone that showed the strongest immunoreactivity, designated Be82, was further characterized. The Be82 gene consisted of 1,953 bp and contained a partial open reading frame lacking the 5'-terminal sequence. As shown by Western blot analyses, immune sera from mice intraperitoneally injected with the Be82 gene product recognized the 82- and 52-kDa proteins of B. equi but not those of Babesia caballi. The glutathione S-transferase fusion protein expressed in Escherichia coli that was purified and used as the antigen in the enzyme-linked immunosorbent assay reacted specifically with B. equi-infected horse sera. These results suggest that the Be82 gene product is a potential diagnostic antigen candidate in the detection of B. equi infection in horses that will be useful both in the performance of epidemiological studies and in the granting of quarantine passes.     

Correspondence of cue activity to reward activity in the macaque orbitofrontal cortex

It has been reported that neurons in the orbitofrontal cortex (OFC) respond to emotionally significant events such as reward-predicting cues and/or the reward itself. The responses to reward-predicting cues are considered to carry the information of the predicted reward. However, few studies have focused on the relationship of the neuronal activity during a cue period with that during a reward period. We can infer that the cue responses of OFC neurons are correlated to the reward responses if they carry the information of the predicted reward. In this study, we focused on neurons that showed responses during both the cue and reward periods, and compared the response characteristics between these periods. We found 94 of 369 OFC neurons showed significant responses during both the cue and reward periods, and 43 of which preserved their selectivity between these periods. Furthermore, population analysis showed that stronger cue responses corresponded to stronger reward responses, and stronger reward responses corresponded to stronger cue responses. These results suggest that individual neurons in the OFC associate visual information with reward information, and contribute to the prediction of future rewards by forming reward representations.