Search PubMed⌕ Search

Biomedical subjects

Y Minamishima

Publications and source records attributed to Y Minamishima.

At least 55 records · Page 3Linked to original sources
PubMed1993

Progressive encephalopathy associated with cytomegalovirus infection without immune deficiency.

Slowly progressive encephalopathy caused by cytomegalovirus is an unusual disorder, and its pathogenesis remains unknown except for cases associated with the acquired immune deficiency syndrome and organ transplantation. We report a case who showed clinical features of progressive encephalopathy. Cytomegalovirus was repeatedly isolated from urine, and cytomegalovirus-infected cells were detected in bone marrow. Serial computed tomographic head scan revealed periventricular calcification and its progression to the thalamus, cerebellum, and brain stem. On autopsy, there were multiple calcifications and diffuse glial proliferation in the gray and white matter. Perivascular inflammation was only minimal. There was no evidence of immune deficiency. This case suggests that progressive encephalopathy can be caused by cytomegalovirus infection without immune deficiency. This type of cytomegalovirus infection may be unusual, but its serious outcome should remind us to detect it accurately.

Brain↗
PubMed1993

Cytomegalovirus, human herpesvirus 6 and human T cell leukemia virus infection in renal transplanted patients in the northeast of Brazil.

The seroprevalence of antibodies against cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and human T cell leukemia virus type 1 (HTLV-1), determined by ELISA and by fluorescence in 54 renal transplanted patients, was 96.2%, 88.8% and 11.1%, respectively. These values are relatively high when compared with the results obtained for healthy individuals of the same age groups from Recife, Northeastern Brazil. Active CMV infection was detected by the presence of IgM antibodies and/or virus isolation in 13 (24%) patients. Kidney rejection and renal dysfunction were observed in 11 of these 13 patients, whereas 3 of 6 HTLV-1 antibody-positive individuals presented these complications. All HTLV-1 positive patients were also positive to IgG CMV and HHV-6 antibodies. The importance of the three viruses in this clinical condition is suggested by the high seropositivity rates compared with the healthy population. The group may also represent a potential source of HTLV-1 infection in this non-endemic area.

Adolescent↗
PubMed1993

[Idiopathic interstitial pneumonitis possibly associated with chronic graft-versus-host disease].

We described two cases of idiopathic interstitial pneumonitis (IP) after allogeneic bone marrow transplantation (BMT), who were successfully treated with prednisolone (PSL). A 40-year-old male with AML (M3) in the first remission (case 1) and a 36-year-old male with CML in chronic phase (case 2) were treated with BMT from HLA genotypically identical female siblings. Both patients were conditioned with busulfan (16mg/kg) and cyclophosphamide (120mg/kg), and given a combination of cyclosporin A and methotrexate to prevent acute GVHD (aGVHD). Engraftment of donor marrow was documented in both cases. Grade I of aGVHE developed in case 1 and no aGVHD in case 2. Both patients had clinical manifestations of chronic GVHD (cGVHD), which were followed by dyspnea and cough without fever 120 days (case 1) or 100 days (case 2) after BMT. Abnormal lung function tests and radiographic infiltrates indicated that patients developed IP, but causative microorganisms could not be detected in the bronchoalveolar lavage (BAL) specimens. Subjective symptoms disappeared in a few days after administering PSL (1mg/kg/day). Laboratory data also improved thereafter. These observations, including the development of radiographic infiltrates along with clinical manifestations of cGVHD, absence of febrile episodes, absence of causative microorganisms in the BAL specimens, and effectiveness of immunosuppressive drugs, suggested that idiopathic IP observed in our cases might be a manifestation of cGVHD.

Adult↗
PubMed1992

Reactivation of cytomegalovirus in patients with cirrhosis: analysis of 122 cases.

Human cytomegalovirus causes severe and often fatal infections in immunocompromised patients. After organ transplantation cytomegalovirus in peripheral blood mononuclear cells is thought to be activated by alloreaction and to spread because of immunosuppression, and it may cause endogenous cytomegalovirus diseases. Patients with cirrhosis, one group of candidates for liver transplantation, often show various grades of immunosuppression before transplantation. To evaluate the status of cytomegalovirus infection in cirrhotic patients and its relevance to the degree of immunosuppression, we examined the presence of cytomegalovirus in mononuclear cells by polymerase chain reaction and immunocytochemical analysis. We studied 122 patients with definite cirrhosis and 43 normal volunteers. All cirrhotic patients (100%) and 40 (93%) of 43 normal controls were seropositive for cytomegalovirus. Cytomegalovirus DNA was detected by polymerase chain reaction in 77 (63.1%) of 122 seropositive cirrhotic patients, but in only 1 (2.5%) of 40 seropositive normal controls (p < 0.01). Cytomegalovirus antigen could not be detected in mononuclear cells by immunocytochemical staining with monoclonal antibodies. Cytomegalovirus DNA-positive patients have a greater impairment of liver function than do cytomegalovirus DNA-negative patients; this fact is manifested by delayed indocyanine green retention rates and elevated serum bilirubin levels (p < 0.05). Lymphocyte proliferative response induced by phytohemagglutinin and natural killer cell activity were also significantly lower in cytomegalovirus DNA-positive patients as compared with cytomegalovirus DNA-negative patients (p < 0.01). Our data suggest that the reactivation of cytomegalovirus may have already occurred in patients with cirrhosis before transplantation.

Adult↗
PubMed1992

Murine cytomegalovirus DNA polymerase: purification, characterization and role in the antiviral activity of acyclovir.

Murine cytomegalovirus (MCMV) neither induces a viral thymidine kinase (TK) nor enhances the activity of a cellular TK. Nevertheless, MCMV is highly susceptible to 9-(2-hydroxyethoxymethyl)guanine (acyclovir, ACV). The cellular TK is neither responsible for phosphorylation of ACV nor its anti-MCMV activity. This is clear from the findings that little ACV triphosphate is formed in MCMV-infected mouse embryo fibroblasts (MEF) and that the replication of MCMV is inhibited equally well by ACV in TK+ and TK- cells. Even if trace amounts of ACV triphosphate would be formed by enzymes other than TK, and ACV triphosphate would be responsible for the anti-MCMV activity of ACV, then the MCMV DNA polymerase ought to be highly sensitive to ACV triphosphate. To examine this possibility, the MCMV DNA polymerase was partially purified and characterized. The apparent Ki value of the MCMV DNA polymerase for ACV triphosphate indicates that the sensitivity of the MCMV DNA polymerase to ACV triphosphate is equivalent to that of the HSV DNA polymerase. Therefore, the trace amounts of ACV triphosphate that are formed in MCMV-infected MEF seem to be insufficient to inhibit MCMV DNA polymerase and may not play a key role in the anti-MCMV activity of ACV.

Acyclovir↗
PubMed1992

Evidence for putative immediate early antigens in human herpesvirus 6-infected cells.

Human herpesvirus 6 (HHV-6) induced nuclear antigens in cells as early as 3 h after infection. These nuclear antigens were induced by all three strains of HHV-6 tested, and their de novo synthesis required the function(s) of the intact viral genome. Their appearance was not affected by 2,2'-anhydro(1-beta-D-arabinofuranosyl)cytosine, but was completely inhibited by cycloheximide. However, the nuclear antigens did appear if cycloheximide was replaced with actinomycin D. Thus, the nuclear antigens seem to be equivalent to the immediate early antigens of other herpesviruses.

Antibodies, Viral↗
PubMed1992

Jejunal perforation associated with cytomegalovirus infection in a patient with adult T-cell leukemia-lymphoma.

A patient with adult T-cell leukemia-lymphoma suffered a jejunal perforation, which we believe was directly attributable to cytomegalovirus (CMV) infection. In the areas of ulceration and perforation in the small bowel, blood vessels penetrating the muscularis propria showed extensive lining of cytomegalic endothelial cells with CMV inclusions, accompanied by occasional disruption of the walls, partial occlusion of the lumina, fibrin thrombi, and hemorrhage. The CMV-induced vascular damage seemed to be closely related to the occurrence of ulcers and perforation. The recognition of CMV as a cause of lethal gastrointestinal lesions in immunocompromised hosts has become more important with the advent of anti-CMV therapy.

Adult↗
PubMed1992

Detection of rubella virus-specific polymeric immunoglobulin A by enzyme-linked immunosorbent assay in combination with streptococcal pretreatment of serum.

An enzyme-linked immunosorbent assay combined with streptococcal treatment of serum was assessed for its ability to detect serum polymeric immunoglobulin A. This technique detects rubella virus-specific polymeric immunoglobulin A antibody, which appears for only a short time after infection, and it is useful for serodiagnosis of recent rubella virus infection.

Antibodies, Viral↗
PubMed1991

Rapid diagnosis of cytomegalovirus infections by direct immunoperoxidase staining with human monoclonal antibody against an immediate-early antigen.

Direct immunoperoxidase technique using a horseradish peroxidase (HRP)-conjugated Fab' fragment of human monoclonal antibody (humab C7), designated HRP-C7, was evaluated as a rapid diagnosis of cytomegalovirus (CMV) infection. A total of 138 clinical specimens consisting of 124 urine samples and 14 oral swabs were examined for CMV by the direct HRP-C7 staining in comparison with conventional virus isolation. The number of CMV-positive samples by each method was 40 (29.0%) for the former and 37 (26.8%) for the latter, respectively. By HRP-C7 staining, CMV was identifiable within 24 hr after inoculation. By conventional isolation method, an average of 10.3 days had passed before cytopathic effect characteristic of CMV appeared in the cell culture. Some false-positive and false-negative cases were discussed in relation to toxicity of urine samples, storage of the samples, and amount of CMV in the sample. The sensitivity and specificity of HRP-C7 method against conventional isolation method were 89.2% and 93.1%, respectively. Thus, HRP-C7 staining is useful for a rapid diagnosis of CMV infections.

Antibodies, Monoclonal↗
PubMed1991

Seroprevalence of human herpesvirus 6 infection in Brazilian and Japanese populations in the north-east of Brazil.

The seroprevalence of human herpesvirus 6 (HHV-6) infection was examined for 434 Brazilians and 250 Japanese immigrants living in Recife and its vicinity, in the North-East of Brazil. A total of 684 sera from the healthy individuals were screened for IgG antibodies to HHV-6 by anticomplement immunofluorescence (ACIF) test. The seropositivity rate to HHV-6 showed little difference between the two groups: namely, it was 76.5% for Brazilians and 77.2% for Japanese immigrants. The seropositivity rate was constantly higher in females than in males. The high prevalence of anti-HHV-6 antibodies among children indicates that HHV-6 infection occurs very early in life.

Adolescent↗
PubMed1991

Differential susceptibility of a rat glioma cell line and its clones to herpes simplex virus types 1 and 2.

A rat glioma cell line, C6-BU-1, showed differential susceptibility to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), namely, all the HSV-1 strains tested so far persisted in this cell line but the HSV-2 strains did not. Two clones were derived from C6-BU-1 cells and designated C-17 and C-72. The C-72 as well as the parental C6-BU-1 cells supported the replication of HSV-1, but not that of HSV-2. In contrast, C-17 was highly resistant to both HSV-1 and HSV-2. Hydrocortisone treatment converted C-17 to being susceptible to HSV-1, but not to HSV-2. Therefore, C6-BU-1 cells consist of subpopulations heterogeneous in susceptibility to HSV-1 which may be possibly interchangeable.

Animals↗
PubMed1990

Antiviral effect of antileukemic drugs N4-behenoyl-1-beta-D-arabinofuranosylcytosine (BH-AC) and 2,2'-anhydro-1-beta-D-arabinofuranosylcytosine (cyclo-C) against human cytomegalovirus.

The antiviral activities of antileukemic drugs 1-beta-D-arabinofuranosylcytosine (Cytarabine; Ara-C), 2,2'-anhydro-1-beta-D-arabinofuranosylcytosine (Ancitabine; Cyclo-C), and N4-behenoyl-1-beta-D-arabinofuranosylcytosine (Enocitabine; BH-AC) were evaluated in vitro against human cytomegalovirus (HCMV) in comparison with those of five other antiviral drugs. Both Ara-C and Cyclo-C showed the strongest inhibitory effect to HCMV. BH-AC inhibited the replication of HCMV and depicted almost as the same dose-response curve as Ganciclovir (DHPG). In the presence of Ara-C, Cyclo-C, or BH-AC, triphosphate forms of the nucleoside analogs were detected in the HCMV-infected cells, and synthesis of HCMV DNA was strongly suppressed. Thus, Ara-C, Cyclo-C, and BH-AC were not only antileukemic, but also antiviral in vitro. However, Ara-C and Cyclo-C may not be suitable as anti-HCMV agents, because they are cytotoxic or excreted rapidly in the urine in vivo [Van Voris, 1984; Hirayama et al., 1974]. Because of lower toxicity and longer retention in vivo, BH-AC may be expected as an anti-HCMV agent in patients with leukemia, in addition to serving as an antileukemic drug.

Ancitabine↗
PubMed1990

Independent existence of mutations responsible for temperature sensitivity and attenuation in a mutant of murine cytomegalovirus.

A temperature-sensitive (ts) mutant of murine cytomegalovirus, ts21, lacks pathogenicity for suckling mice. Revertants (rev21) of ts21 which could replicate at nonpermissive temperature remained attenuated, suggesting the presence of a temperature-independent factor(s) for the attenuation. Coinfection of ts21 with its parental wild-type (wt) generated recombinant-type progenies (rec21w) which lacked temperature sensitivity and were still attenuated. The results indicate that ts21 harbors at least two mutations and the mutation(s) in pathogenicity exists independently of the ts mutation(s).

Animals↗
PubMed1990

Detection by polymerase chain reaction amplification of human herpesvirus 6 DNA in peripheral blood of patients with exanthem subitum.

The polymerase chain reaction was used to detect human herpesvirus 6 (HHV-6) DNA in peripheral blood mononuclear cells from patients with exanthem subitum. Amplified products were detected by agarose gel electrophoresis and dot blot hybridization with a cloned DNA probe. No cross-hybridization with DNAs of five other human herpesviruses was observed in this system, and all HHV-6 strains gave positive reactions when the primer pairs were used. Immunoglobulin M antibody appeared about 5 days after the onset of disease, reaching a maximum after about 2 to 3 weeks and then decreasing to less than 1:10 1 month after the onset of disease in almost all patients. Mononuclear cells from seven patients with exanthem subitum all gave positive reactions in this system, and viral DNA was found in samples even during the convalescent phase of the disease. We conclude that this test, using polymerase chain reaction amplification, which takes only 1 to 2 days, is useful for the diagnosis of HHV-6 infection.

Antibodies, Viral↗
PubMed1990

Isolation of multiple cytomegalovirus strains from a patient with adult T cell leukemia.

A 66-year-old male with adult T cell leukemia had an ulcer on the left medial thigh. The biopsy of the skin lesion revealed enlarged endothelial cells with acidophilic intranuclear inclusion bodies, suggesting cytomegalovirus (CMV) infection. At autopsy, CMV was isolated from a nodular skin lesion of the scrotum. The urine constantly tested positive for CMV. Restriction endonuclease cleavage analysis of DNA of the isolates from the skin and urine indicated that this patient was infected with two different strains of CMV.

Aged↗
PubMed1990

Effect of Chlorella vulgaris extracts on murine cytomegalovirus infections.

The host-mediated antiviral effect of Chlorella vulgaris extracts (CVE) was evaluated in ICR mice against murine cytomegalovirus (MCMV) infection. Mice treated with 10 mg of CVE on days 3 and 1 before virus challenge survived lethal infection. The protective effect of CVE was shown by a decrease in the infectious viruses replicated in the target organs of CVE-treated ICR mice. CVE also protected mice from histopathological damage to the target organs due to MCMV infection. Both the serum interferon (IFN) level and 2'5'-oligoadenylate (2-5A) synthetase activity were elevated in CVE-treated and MCMV-infected mice, and were higher than those in the control mice. The natural killer (NK) activity of spleen cells, which is otherwise deteriorated by lethal MCMV infection, was remarkably augmented in CVE-treated mice. Neither virocidal nor virostatic activity of CVE on MCMV was seen in vitro. Thus, CVE-induced resistance against MCMV seems to be host-mediated. The protective effect correlated with the augmentation of NK activity of the spleen cells and serum IFN activity, which inhibited replication of MCMV in the target organs and subsequently saved the mice from death.

2',5'-Oligoadenylate Synthetase↗