[Evaluation of paravalvular leakage occurring after the 3rd mitral valve replacement]

We evaluated the frequency of paravalvular leakage (PVL) in 21 patients who had undergone mitral valve replacement (MVR) 3 times or more in our department between January 1981 and December 2003. Of these 21 patients, 5 underwent MVR 4 times, including the one who underwent the 5th MVR. Seven (38%) of 18 patients who had successfully undergone MVR 3 times and all 2 patients who had successfully undergone MVR 4 times developed PVL. PVL recurred in 6 (67%) of 9 patients who had undergone the 3rd MVR due to the occurrence of PVL. However, PVL recurred in only 1 (11%) of 9 patients who had undergone the 3rd MVR due to some postoperative complications other than PVL. Among 10 patients who developed PVL after the 1st or 2nd MVR, PVL recurred in 7 patients after the 3rd MVR. However, among 8 patients who did not develop PVL after the 1st or 2nd MVR, PVL occurred after the 3rd MVR only in 1 patient. These findings suggest that repeated MVR increases the incidence of PVL, and that patients with a past history of PVL are at a higher risk of developing PVL after repeated MVR.

Generation of anti-tumour effector T cells from naïve T cells by stimulation with dendritic/tumour fusion cells

Tumour-draining lymph node T cells are an excellent source of effector T cells that can be used in adoptive tumour immunotherapy because they have already been sensitized to tumour-associated antigens in vivo. However, such tumour-specific immune cells are not readily obtained from the host due to poor immunogenicity of tumours and reduced host immune responses. One obstacle in implementation of adoptive immunotherapy has been insufficient sensitization and expansion of tumour-specific effector cells. In this study, we aim to improve adoptive immunotherapy by generating anti-tumour effector T cells from naïve T lymphocytes. We attempted to achieve this by harnessing the advantages of dendritic cell (DC)-based anti-cancer vaccine strategies. Electrofusion was routinely employed to produce fusion cells with 30-40% efficiency by using the poorly immunogenic murine B16/F10 cell line, D5 cells, and DC generated from bone marrow cells. CD62L-positive T cells from spleens of naïve mice and the fusion cells were cocultured with a low concentration of IL-2. After 9 days of culture, the antigen-specific T cells were identified with an upregulation of CD25 and CD69 expression and a downregulation of CD62L expression. These cells secreted IFN-gamma upon stimulation with irradiated tumour cells. Moreover, when transferred into mice with 3-day established pulmonary metastases, these cells with coadministration of IL-2 exhibited anti-tumour efficacy. In contrast, naïve T cells cocultured with a mixture of unfused DC and irradiated tumour cells did not exhibit anti-tumour efficacy. Our strategy provides the basis for a new approach in adoptive T cell immunotherapy for cancer.

Molecular phylogeny of Trypanosoma cruzi from Central America (Guatemala) and a comparison with South American strains

Molecular phylogenetic analysis was carried out for 21 strains of Trypanosoma cruzi, nine of which were obtained from Guatemala and 12 from South America. Phylogenetic trees were constructed using the nucleotide sequences of two nuclear gene regions, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and trypanothione reductase (TR), and contiguous portions of two mitochondrial genes, cytochrome oxidase subunit II (COII) and reduced nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1). Possible genetic exchange between the rather divergent lineages of T. cruzi II from South America was suggested in the trees of the two nuclear genes. T. cruzi I strains obtained from Guatemala and Colombia were identical in all the genes examined, but other T. cruzi I isolates from South America were rather polymorphic in the DHFR-TS and mitochondrial genes. No genetic exchange was identified between T. cruzi I populations from Central and South America in the present study.

Do all angiotensin II type 1 receptor blockers have the same beneficial effects?

Angiotensin II type 1 (AT(1)) receptor blockers (ARBs) are highly selective for the AT(1) receptor, which is a member of the G protein-coupled receptor superfamily (GPCRs), and block the diverse effects (hypertension, hypertrophy, heart failure, proteinuria etc.) of angiotensin II. Many ARBs are in clinical use and have been shown to be safe and effective. Over the past several years, reports have discussed the different degrees of the beneficial effects of ARBs. As ARBs do not all have the same effects, the benefits conferred by ARBs may not be class effects. These different effects may be due to differences in the molecular characteristics of ARBs. The results reported by Le et al. in this issue highlight the different characteristics of two ARBs, olmesartan and telmisartan, and suggest that the higher degree of insurmountability, slower dissociation, and higher affinity of olmesartan compared to telmisartan for AT(1) receptors may help it to form a tight binding complex with this receptor. A better understanding of the different molecular mechanisms for each ARB could be useful for the treatment of patients.

The contactin 4 gene locus at 3p26 is a candidate gene of SCA16

OBJECTIVE

To identify of the gene responsible for the onset of spinocerebellar ataxia type 16 (SCA16).

METHODS

We reanalyzed the linkage of the original Japanese pedigree using updated information, including three additional subjects. We then screened all exons located in the critical region.

RESULTS

We reassigned the locus of SCA16 to 3p26.2-pter (maximum logarithm-of-odds score = 5.177) and identified only one point mutation (4,256C-->T) in the 3' untranslated region of the contactin 4 gene (CNTN4) on chromosome 3p26.2-26.3, which cosegregated with the disease. This mutation was not detected in 520 control subjects; moreover, we revised the phenotype of SCA16 from pure to complicated SCA.

CONCLUSION

The contactin 4 gene (CNTN4) is associated with cerebellar degeneration in spinocerebellar ataxia type 16. Additional studies are necessary to prove 4,256C-->T to be a causative mutation.

Streptococcal origin of a case of Henoch-Schoenlein purpura nephritis

We report the case of a 25-year-old man with abdominal pain, purpura on the legs and proteinuria occurring 2 weeks after acute tonsillitis, and admitted to our hospital with suspected Henoch-Schönlein purpura nephritis (HSPN). He had increased anti-streptolysin O (ASO) titer and hypocomplementemia. A renal biopsy specimen showed endocapillary proliferative changes, which are typical of acute poststreptococcal glomerulonephritis (APSGN). However, immunofluorescence study revealed predominant IgA and C3 deposits in mesangial lesions, indicating a diagnosis of HSPN. Because of massive proteinuria initially, the treatment with a combination of prednisolone, cyclophosphamide, dipyridamole and warfarin was started along with 3 plasma exchanges. Angiotensin-converting enzyme inhibitor was also given. Response to the treatment was favorable. A follow-up biopsy was performed 8 months after the first biopsy. The renal biopsy specimen showed a figure of typical HSPN. To further investigate the cause of glomerular changes in our patient, an immunofluorescent study of nephritogenic nephritis-associated plasmin receptor (NAPlr) of group A, beta-hemolytic streptococci was performed. NAPlr was significantly positive in the glomeruli in the first biopsy specimen, but not in the second. His clinical course and pathological findings suggest that NAPlr may be related to the pathogenesis in a part of patients with HSPN, especially in patients with high ASO titer and hypocomplementemia.

Propionibacterium freudenreichii component 1.4-dihydroxy-2-naphthoic acid (DHNA) attenuates dextran sodium sulphate induced colitis by modulation of bacterial flora and lymphocyte homing

BACKGROUND AND AIMS

1.4-Dihydroxy-2-naphthoic acid (DHNA), a bifidogenic growth stimulator from Propionibacterium freudenreichii, is thought to have a beneficial effect as a prebiotic; however, its in vivo effect on intestinal inflammation remains unknown. The aim of this study was to determine whether oral administration of DHNA can ameliorate dextran sodium sulphate (DSS) induced colitis and to determine the possible underlying mechanisms.

METHOD

Colitis was induced in mice by treatment with 2.0% DSS for seven days. DHNA (0.6 or 2.0 mg/kg) was given in drinking water prior to (preventive study) or after (therapeutic study) DSS administration. Colonic damage was histologically scored, and mucosal addressin cell adhesion molecule 1 (MAdCAM-1) expression and beta7 positive cell infiltration were determined by immunohistochemistry. mRNA levels of proinflammatory cytokines (interleukin (IL)-1beta, IL-6 and tumour necrosis factor alpha (TNF-alpha)) were determined by quantitative real time polymerase chain reaction. In addition, bacterial flora in the caecum, concentrations of short chain acids, and luminal pH were examined.

RESULTS

DHNA improved survival rate and histological damage score in mice administered DSS in both the preventive and therapeutic studies. DHNA significantly attenuated the enhanced expression of MAdCAM-1, the increased beta7 positive cell number, and the increased mRNA levels of IL-1beta, IL-6, and TNF-alpha in DSS treated colon. In addition, the decreased number of Lactobacillus and Enterobacteriaceae induced by DSS was recovered by DHNA. Preventive effects on decrease in butyrate concentration and decrease in pH level in mice administered DSS were also observed in the DHNA preventive study.

CONCLUSION

DHNA, a novel type of prebiotic, attenuates colonic inflammation not only by balancing intestinal bacterial flora but also by suppressing lymphocyte infiltration through reduction of MAdCAM-1.

Herpes simplex esophagitis in the immunocompetent host

We report here a case of herpes esophagitis with Mallory-Weiss syndrome in an immunocompetent host. A 26-year-old man was admitted to our hospital because of common cold symptoms and eruptions on the body. On day 2 after hospitalization, the patient showed high-grade fever, odynophagia and hematemesis. Upper gastrointestinal endoscopic examination showed multiple ulcerations throughout the mid- and distal esophagus. Bleeding from a Mallory-Weiss tear was also seen. Follow-up endoscopic examinations showed whitish exudates on day 5. Histological examination of biopsy specimens showed Cowdry type A intranuclear inclusion bodies in epithelial cells. Positive staining of a specific antibody against herpes simplex virus-1 (HSV-1) was seen in the nuclei of esophageal epithelial cells. Primary HSV-1 infection was suspected because ELISA titers of serum IgM antibody against HSV-1 were high and titers of serum IgG antibody against HSV-1 increased from an almost cut-off ratio. A diagnosis of herpes esophagitis in an immunocompetent host was made. Our case is the first report of herpes esophagitis with Mallory-Weiss syndrome in the immunocompetent host. It is important to remind herpes esophagitis in cases of severe odynophagia even in immunocompetent hosts.

Cross-cultural equivalence in depression assessment: Japan-Europe-North American study

OBJECTIVE

Worldwide use of the Hamilton Rating Scale for Depression (HRSD) presupposes that depression symptomatology can be measured the same way across countries but no empirical study has yet examined this issue. We therefore examined cross-cultural consistency of factor structure of HRSD.

METHOD

A 17-item HRSD data were sought for 5,185 individuals diagnosed with major depression in Japan, Europe and North America. Candidate factor structures were obtained with simultaneous component analysis (SCA) across the three cultures. They were then submitted to multiple-group confirmatory factor analysis (CFA).

RESULTS

According to SCA, 3-, 4- or 5-factor solutions were found to optimally and adequately summarize the variables for all the three populations. When submitted to CFA, the 5-factor solution was the best fitting and the most parsimonious: they were 'anhedonia/retardation,''guilt/agitation,''bodily symptoms,''insomnia' and 'appetite.'

CONCLUSION

Common underlying factors exist for HRSD among Japanese, European and American patients with major depression.