Biomedical subjects

Shinya Hara

Publications and source records attributed to Shinya Hara.

14 recordsLinked to original sources

PubMed2006

Rapid detection of Epstein-Barr virus DNA by loop-mediated isothermal amplification method.

BACKGROUND: The loop-mediated isothermal amplification (LAMP) method is a novel technique for the amplification of specific DNA sequences. OBJECTIVES: To establish the LAMP method for amplifying Epstein-Barr virus (EBV) DNA and to examine its reliability for the detection of EBV DNA in clinical specimens. STUDY DESIGN: Sera from 108 patients, who were initially suspected of primary EBV infection, were tested by the EBV LAMP method, and the results were compared with those of the real-time PCR assay. Serological examination was regarded as the standard diagnostic method. RESULTS: To diagnose primary EBV infection, the sensitivity of LAMP was 86.4% and the specificity was 100%. The sensitivity of the real-time PCR assay was 84.1% and the specificity was 98.4%. Longitudinal analysis showed that the detection rate of EBV DNA in serum by the LAMP method decreased with time in accordance with the decrease of the EBV load. EBV DNA could not be detected in serum 40 days after onset of symptoms. CONCLUSIONS: These results indicate that the sensitivity and specificity of the LAMP method are comparable to those of real-time PCR and that detecting EBV DNA in serum by this method is potentially useful for diagnosing primary EBV infection.

Child, Preschool↗

PubMed2006

Evaluation of apoptosis in Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis.

Epstein-Barr virus (EBV) is known to be a causative agent of hemophagocytic lymphohistiocytosis (HLH). To investigate association of apoptosis in the pathogenesis of EBV-associated HLH, the serum EBV loads, and serum concentrations of soluble tumor necrosis factor receptor 1 (sTNF-R1), soluble Fas ligand, and cytochrome c were examined in 15 patients with EBV-associated HLH and 24 patients with infectious mononucleosis (IM). Levels of sTNF-R1 are known to reflect the biological activity of TNF-alpha and cytochrome c is a specific marker of apoptosis. EBV loads, and concentrations of sTNF-R1 and cytochrome c were significantly higher in patients with EBV-associated HLH than in patients with IM. On the other hand, there were no statistically significant differences in the concentrations of soluble Fas ligand. In patients with EBV-associated HLH, EBV loads, concentrations of sTNF-R1, and cytochrome c were correlated with each other. These results suggest that apoptosis, which is dependent on the EBV load and could be mediated by TNF-alpha, plays a major role in the pathophysiology of EBV-associated HLH.

Apoptosis↗

PubMed2006

Clonality analysis by sequence variation of the latent membrane protein 1 gene in patients with chronic active Epstein-Barr virus infection.

Chronic active Epstein-Barr virus (EBV) infection is a severe systemic disease associated with high rates of mortality and morbidity. Recent studies suggest that the clonal expansion of EBV-infected T or natural killer cells plays a crucial role in the pathogenesis of chronic active EBV infection. However, it is not clear whether chronic active EBV infection is truly a monoclonal disorder that originates from one cell. The clonality of EBV was investigated by sequence variation of the latent membrane protein 1 (LMP1) gene, which has a high degree of sequence heterogeneity. Peripheral blood mononuclear cells were obtained from nine Japanese patients with chronic active EBV infection and four with infectious mononucleosis. A carboxyl-terminal region of the LMP1 gene was analyzed by polymerase chain reaction (PCR). The amplified PCR products were subcloned, and 18 clones from each sample were sequenced. Patients with chronic active EBV infection each had two to five different LMP1 nucleotide sequences, whereas patients with infectious mononucleosis each had one to seven different sequences. Patients with chronic active EBV infection and infectious mononucleosis both had one dominant sequence. Longitudinal analysis was performed in four patients with chronic active EBV infection, in whom the dominant strains were found to have remained unchanged for several years. The results suggest that EBV in patients with chronic active EBV infection was polyclonal, although clonal expansion may occur. Collectively, these findings are critical to clarify further the pathogenesis of chronic active EBV infection and aid in the development of effective treatment strategies.

Adolescent↗

PubMed2006

Quantitative analysis of herpesvirus load in the lymph nodes of patients with histiocytic necrotizing lymphadenitis using a real-time PCR assay.

The cause of histiocytic necrotizing lymphadenitis (HNL) has been ascribed to viral infection, but its pathogenesis still remains unknown. Real-time PCR assays are useful not only for their sensitivity of detection but also for the quantitation of viral DNA with a wide linear range. We accordingly used this technique to estimate for each patient the viral load of the following members of the herpesvirus family: Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpesvirus (HHV) types 6, 7, and 8. Samples of patients diagnosed as reactive lymphadenopathy (RL) were included for control. Thirty percent (6/20 cases) and 63% (12/19 cases) of the HNL and RL patients were positive for EBV, and the mean of the detectable EBV viral load of the HNL and that of the RL patients were 463 and 355 (copies/mug DNA), respectively. By in situ hybridization, EBV-encoded RNA could be detected in the lymph tissue samples with more than 14.3 copies/mug of EBV DNA. No significant difference was detected between the number of HNL patients with HHV6 DNA (3/20, 15%) or HHV7 DNA (2/20, 10%) and RL controls. CMV and HHV8 were not detected in the DNA from any patient. In this study, we were unable to definitively identify the causative herpesvirus for HNL; however, 1 HNL case had an extremely large copy number of HHV6-DNA and displayed positive immunostaining for the HHV6 early/late antigen in lesional areas of the node, suggesting that HHV6 infection may be associated with some cases of HNL.

Adolescent↗

PubMed2005

Association of virus infected-T cell in severe hepatitis caused by primary Epstein-Barr virus infection.

BACKGROUND: Infectious mononucleosis owing to primary Epstein-Barr virus (EBV) infection sometimes causes hepatitis, which is usually self-limiting with mildly elevated transaminases, but can rarely develop into severe hepatitis with jaundice. OBJECTIVE: To clarify the pathogenesis of severe hepatitis by primary EBV infection. METHODS: We experienced four cases of severe hepatitis with jaundice caused by primary EBV infection. These cases were analyzed virologically and histologically, and compared with infectious mononucleosis patients without jaundice. RESULTS AND DISCUSSION: Using real-time PCR, more EBV-DNA was detected in peripheral blood from patients with severe hepatitis, as compared to those without jaundice. Furthermore, CD3+, CD4+ or CD8+ cells contained more EBV DNA than did other cell populations, indicating that in severe hepatitis, T cells harbor most of the EBV. By contrast, mainly B cells were infected in infectious mononucleosis patients without jaundice. The liver was biopsied in three of the four cases. An in situ hybridization study showed that EBV infected lymphocytes, not hepatocytes. In addition, in one patient, it was confirmed that the infected lymphocytes were CD8+ T cells. These results suggest that a large EBV burden and T cell infection may play major roles in the mechanism of severe hepatitis caused by primary EB virus infection.

Adolescent↗

PubMed2005

Differences between T cell-type and natural killer cell-type chronic active Epstein-Barr virus infection.

Infections of T cells and natural killer (NK) cells play a central role in the pathogenesis of chronic active Epstein-Barr virus (CAEBV) infection. To characterize the virologic and cytokine profiles of T cell-type and NK cell-type infection, 39 patients with CAEBV infection were analyzed. Patients with T cell-type infection had higher titers of immunoglobulin G against early and late EBV antigens, suggesting lytic cycle infection. However, the pattern of EBV gene expression was latency type II; BZLF1, which is a hallmark of lytic cycle infection, could not be detected in any patients, regardless of infection type. Patients with CAEBV infection had high concentrations of proinflammatory, T helper cell type 1, and anti-inflammatory cytokines. The cytokine profile in patients with NK cell-type infection was similar to that in patients with T cell-type infection, but the concentration of IL-13 was high in patients with NK cell-type infection. These findings should help to clarify the pathogenesis of CAEBV infection and facilitate the development of more-effective treatments.

Adolescent↗

PubMed2005

[Ischemia of the sternocleidomastoid muscle following occipital artery embolization for dural arteriovenous fistula].

We report a case of localized ischemia of the sternocleidomastoid muscle (SCM) occurring after occipital artery embolization of a dural arteriovenous fistula (dAVF). A 45-year-old man presented intracerebral hemorrhage from a dAVF at the left transverse-sigmoid sinus. The dAVF had a high flow fistula from the left occipital artery (OA). Endovascular therapy was carried out one month later. Transarterial embolization of the OA was carried out prior to the transvenous approach to decrease the shunt flow. During obliteration of the proximal portion of the OA with fiber platinum coils and polyvinyl alcohol particles, the patient reported severe neck pain. The fistula was successfully embolized after transvenous packing of the left sigmoid sinus with detachable coils. The neck pain persisted for one week and disappeared after conservative treatment. T2-MR imaging 3 days after the embolization showed a hyperintensity in the left SCM. This ischemic lesion was probably induced by occlusion of the muscular branch of the OA. We discuss this common but rarely reported complication of OA embolization.

Carotid Artery, External↗

PubMed2004

Quantitative analysis of Epstein-Barr virus (EBV)-specific CD8+ T cells in patients with chronic active EBV infection.

To clarify the pathogenesis of chronic active Epstein-Barr virus (EBV) infection, EBV-specific CD8+ T cells were enumerated, by use of human leukocyte antigen (HLA)-A*2402-restricted tetramers, in 8 patients with chronic active EBV infection, 10 patients with infectious mononucleosis, and 16 EBV-seropositive healthy control subjects. In most of the patients with chronic active EBV infection, EBV-specific CD8+ T cells were not detected. Of note, latent membrane protein 2-specific CD8+ T cells were not detectable in any patients with chronic active EBV infection. In contrast, EBV-specific CD8+ T cells were detected in patients with infectious mononucleosis and in healthy control subjects. Low frequencies of EBV-specific CD8+ T cells may be one of the immunological features of chronic active EBV infection.

Adolescent↗

PubMed2004

[A successfully treated case of a ruptured anterior wall aneurysm of the internal carotid artery (C2) which changed in form from blister-like to saccular type].

We successfully treated a case of ruptured anterior wall aneurysm of the ICA (C2) which changed in form from blister-like to saccular type. A 46-year-old woman developed subarachnoid hemorrhage on July 12, 2002. Cerebral angiogram demonstrated a blister-like aneurysm located in the left C2 portion of the internal carotid artery, but which didn't affect the arterial branches. Because of the risk of premature rupture during early surgery, delayed surgery was scheduled and the patient underwent serial study of the aneurysm. During 2 weeks of follow-up, the shape and size of the aneurysm changed in form blister-like to an enlarged saccular type aneurysm. On the day 18th, a left episubcombined approach, after insertion of a balloon catheter into the cervical ICA, was attempted and the aneurysm projecting antero-medially under the left carotid artery was exposed. The aneurysm had a distinct neck and its wall was not fragile. There was no macroscopic evidence of dissection of the ICA and the aneurysm was successfully clipped by conventional manipulation. Because of the difficulty in determining by angiographic evidence alone, whether an anterior wall aneurysm is a blister type or saccular type, careful follow-up is needed and if the shape or size changes, immediate appropriate treatment becomes mandatory. Intraoperative observation will determine the final diagnosis, as in this uncommon case.

Aneurysm, Ruptured↗

PubMed2003

Systemic cytokine responses in patients with influenza-associated encephalopathy.

Influenza-associated encephalopathy, a severe neurologic complication of influenza, is being reported more frequently in Japan. We investigated the transcription of cytokine genes in peripheral blood leukocytes and compared patients with influenza and with encephalopathy or febrile convulsions and patients with influenza but without neurologic complications. A quantitative polymerase chain reaction (PCR) revealed that transcription of the interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha genes was up-regulated to a greater extent in patients with encephalopathy than in those without neurologic complications. Plasma IL-6 levels also were higher in patients with encephalopathy, although the difference was marginal. Viral RNA in throat swabs was quantified using a real-time quantitative PCR. The virus load was similar among patients with encephalopathy or febrile convulsions or without neurologic complications. Furthermore, virus load was not correlated with either the transcription of cytokine genes or plasma cytokine concentrations. These results suggest that influenza-associated encephalopathy might be a consequence of systemic immune responses.

Child↗

PubMed2003

Combination therapy with intraventricular interferon-alpha and ribavirin for subacute sclerosing panencephalitis and monitoring measles virus RNA by quantitative PCR assay.

Subacute sclerosing panencephalitis (SSPE) is a degenerative disease of the central nervous system that leads to death within a few years. Recently, it has been reported that combination therapy with intraparenchymal interferon-alpha (INF-alpha) and intraventricular ribavirin is effective. An 11-year-old SSPE patient whose clinical symptoms progressed rapidly, was treated first with intraventricular INF-alpha and then with combined intraventricular INF-alpha and ribavirin therapy. To monitor viral load over the course of the therapy, measles virus RNA was quantified using a real-time polymerase chain reaction assay. Measles virus RNA decreased rapidly after the INF-alpha therapy was started, paralleling the decrease in the measles antibody titer in the cerebrospinal fluid and the improvement in the neurological disability. After intraventricular ribavirin was combined with INF-alpha therapy, no further improvement was observed. The neurological disability gradually progressed, although the amount of virus RNA remained low.

Antiviral Agents↗

PubMed2003

Absence of associations between influenza-associated encephalopathy and human herpesvirus 6 or human herpesvirus 7.

BACKGROUND: Influenza-associated encephalopathy is a severe complication of influenza virus infection, but its pathogenesis is unknown. It was recently suggested that the neurologic complications of influenza, including encephalopathy, are associated with human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7). AIM To confirm or refute the association between influenza-associated encephalopathy and HHV-6 or HHV-7. METHODS: Cerebrospinal fluid and serum from 25 patients with central nervous system complications of influenza (18 patients with encephalopathy and 7 patients with febrile convulsions) were investigated. The specimens were examined by real time polymerase chain reaction (PCR) and nested PCR for HHV-6 and HHV-7 DNA. RESULTS: In the cerebrospinal fluid samples neither HHV-6 DNA nor HHV-7 DNA was detected by real time PCR or nested PCR. HHV-6 DNA was detected in a single serum sample from a patient with febrile convulsions. CONCLUSION: In our study there was no association with HHV-6 or HHV-7 in most patients with central nervous system complications of influenza.

Age Distribution↗

PubMed2002

Detection of herpesvirus DNA in the serum of immunocompetent children.

The DNA of herpesviruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 (HHV6), and human herpesvirus-7 (HHV7) has been detected in the serum of patients with primary infection or with immunosuppression. However, it is unknown how frequently herpesvirus DNA can be detected in the serum of immunocompetent children, or whether the detection of herpesvirus DNA indicates an active infection or virus-related diseases. Using a real-time polymerase chain reaction assay, attempts were made to detect herpesvirus DNA in the serum of 176 ambulatory children who visited a hospital for various reasons. EBV was detected in 4 (2.2%), HHV6 in 4 (2.2%), and HHV7 in 2 (1.1%) of 176 children, but CMV was not detected. Of the 10 positive patients, only 4 were considered, by virtue of clinical and serological characteristics, to have primary infections. The other 4 positive patients had other infections, such as mycoplasma and salmonella. Although herpesvirus DNA could be detected in the serum of immunocompetent children, there was not always a relationship between clinical manifestations and the detection of virus DNA. When herpesvirus DNA is detected in the serum, a careful interpretation is necessary to diagnose a primary infection or a virus-associated disease.

Antibodies, Viral↗

PubMed2002

Viral load in Epstein-Barr virus-associated hemophagocytic syndrome.

The viral load in peripheral blood from patients with Epstein-Barr virus (EBV)-associated hemophagocytic syndrome was measured by real-time quantitative PCR and compared with that in infectious mononucleosis. Patients with EBV-associated hemophagocytic syndrome generally had larger viral burdens, although it was difficult to differentiate EBV-associated hemophagocytic syndrome from infectious mononucleosis simply by viral load. The difference in viral load seemed to be clearer in peripheral blood mononuclear cells than in plasma.

Adult↗