Biomedical subjects

T Ando

Publications and source records attributed to T Ando.

At least 55 records · Page 3Linked to original sources

PubMed2002

Clarithromycin increases the release of heat shock protein B from Helicobacter pylori.

BACKGROUND: Clarithromycin (CAM) may have certain indirect effects on Helicobacter pylori (H. pylori) other than its inhibitory activity on bacterial growth, as indicated in other infections with Gram-negative micro-organisms. In the present study, we examined the effects of lower concentrations of CAM on the release of heat shock protein B (HspB), one of the major antigenic proteins from H. pylori cells, as well as the changes in humoral immune response and histological degree of antral gastritis in patients who received eradication therapy with CAM. METHODS: The H. pylori strain 26695 and three CAM-resistant clinical isolates were cultured in broth with and without CAM (2-500 ng/mL). Expression of H. pylori proteins was examined by two-dimensional (2D)-electrophoresis followed by N-terminal amino acid sequencing. Changes in host immune response and histological degree of antral gastritis were monitored in patients with peptic ulcer disease who received H. pylori eradication therapy. RESULTS: 2D electrophoresis showed 26 spots in extracellularly released proteins with different profiles from those in cytoplasmic proteins. The release of HspB increased after incubation with CAM (30-500 ng/mL) in all three H. pylori clinical isolates tested. Patients with failed H. pylori eradication after triple therapy with CAM, but not those with failed eradication after dual therapy without CAM, showed an increase in serum IgG1 and IgG2 antibodies against HspB along with a decrease in the degree of neutrophil and H. pylori colonization density in tissue sections. CONCLUSIONS: CAM may induce a humoral immune response against H. pylori and a decrease in gastric mucosal inflammation through up-regulation of the release of HspB from the bacteria in infected patients.

Amino Acid Sequence↗

PubMed2002

Deep-seated mycosis as a complication in bone marrow transplantation patients.

Achieving control of opportunistic fungal infections which occur during the course of immunosuppressive therapy is one of the key factors deciding the success or failure of bone marrow transplantation (BMT). A review was conducted of autopsied patients who had undergone BMT at the University of California at Los Angeles Medical Center in the USA between 1985 and 1994. The incidence of complication by deep-seated mycoses was determined, and the causative fungal species and invaded organs were elucidated. Deep fungal infections were found to have occurred in 31.5% (47/149 cases) of the BMT patients, and disseminated disease was found in approximately one-quarter of the infected cases. The findings suggest that BMT patients, who require the use of potent immunosuppressive agents, show increased susceptibility to the development of more serious, and widespread diffuse fungal infections. The most commonly detected causative fungi were Aspergillus species and Candida species. In addition, it was found that the incidence of candidosis had decreased markedly in recent years; conversely, aspergillosis had increased. It was surmised that these findings reflect the development of antifungal agents which are effective against candidosis and have enabled a reduction in the incidence of this disease even in BMT patients, whereas aspergillosis remains difficult to treat. In consideration of these findings regarding the manifestation of deep-seated mycosis in BMT patients, we conclude that in order to increase the success rate of BMT it will be essential to establish safe and effective methods for the prevention and treatment of aspergillosis.

Adolescent↗

PubMed2002

Upregulation of mucosal soluble fas ligand and interferon-gamma may be involved in ulcerogenesis in patients with Helicobacter pylori-positive gastric ulcer.

BACKGROUND: Excessive upregulation of gastric epithelial cell apoptosis is speculated to be associated with ulcerogenesis in Helicobacter pylori-positive peptic ulcer disease. H. pylori may have an ulcerogenic effect through induction of gastric epithelial cell apoptosis mediated by infiltrating T cells and their soluble products. METHODS: The contents of soluble Fas ligand (sFasL) and interferon-gamma (IFN-gamma) in organ cultures and the degree of apoptosis and the expression of apoptosis-related proteins in the gastric epithelium were examined using the mucosal tissues obtained from the antrum and the ulcer site in patients with H. pylori-positive gastric ulcer (GU). The molecular mechanisms of gastric epithelial cell apoptosis induced by sFasL and IFN-gamma were analyzed using epithelial cell lines, MKN 45 and KATO III. RESULTS: The mucosal tissues of the ulcer site had substantially higher contents of sFasL and IFN-gamma in organ cultures regardless of its healing stage in association with increased numbers of apoptotic cells and enhanced expression of proapoptotic proteins Bak and Bax in the surface foveolar epithelium as compared with the antral tissues in patients with H. pylori-positive GU. The addition of sFasL caused increases in cytotoxic cell death and caspase-3 activation in MKN 45 and KATO III cells in which IFN-gamma treated cells had more prominent effects than untreated cells. The expression of Bak in MKN 45 cells increased when they were treated with IFN-gamma. CONCLUSIONS: Upregulation of mucosal sFasL and IFN-gamma may be involved in ulcerogenesis in patients with H. pylori-positive GU through induction of gastric epithelial cell apoptosis.

Adult↗

PubMed2002

Polymorphisms of Helicobacter pylori HP0638 reflect geographic origin and correlate with cagA status.

Since the associations between Helicobacter pylori genotype and disease differ in Asia and the West, we investigated the correlation between HP0638, encoding an outer membrane protein, and potential markers of virulence (cagA, vacA, and iceA). For 109 strains from nine countries, the status of cagA, vacA, and iceA was determined by PCR and/or a line probe assay. We also studied 18 strains from 8 patients (parents and 6 daughters) from a Dutch family and paired strains collected on average 8 years apart from 11 patients. When the HP0638 signal sequences were amplified by PCR and DNA sequence determinations were performed, 89 (96%) of 93 cagA-positive strains had HP0638 in frame, versus none (0%) of 16 cagA-negative strains (P < 0.001). Among strains in which HP0638 was in frame, a six-CT dinucleotide repeat pattern was dominant in Western countries (23 of 33 strains [70%]), while a pattern of three CT repeats with another CT after four T's (3 + 1-CT-repeat pattern) was dominant in East Asia (31 of 46 strains [67%]); however, specific CT repeat patterns did not correlate with clinical outcome. HP0638 phylogenetic trees also showed geographic characters. The HP0638 frame status and CT dinucleotide repeat patterns were identical for 9 of 11 pairs of strains obtained on average 8 years apart from individuals and the 15 strains obtained from the mother and all six daughters. Thus, HP0638 frame status and cagA status are strongly correlated. The CT dinucleotide repeat pattern in the putative HP0638 signal sequence has geographic characters and appears stable in particular patients and families over a period of years. Analysis of HP0638 CT polymorphisms may serve as a new typing system to discriminate H. pylori isolates for epidemiological purposes.

Adult↗

PubMed2002

Simultaneous onset of haemorrhagic and ischaemic strokes in a haemodialysis patient.

Primary brain haemorrhage and infarction only very rarely occur simultaneously. A patient with end stage renal disease from diabetic nephropathy suddenly had motor aphasia and horizontal nystagmus soon after finishing haemodialysis. Neuroradiological studies showed a haematoma on the right side of the pons and an infarct in the left frontal lobe with occlusion of the left internal carotid artery. Specific conditions of the haemodialysis--including anticoagulant use, relative hypovolaemia and hypertension just before haemodialysis, and an abrupt decrease in blood pressure during haemodialysis--seemed to be the major reason for the simultaneous onset of dual strokes.

Aged↗

PubMed2001

A high-speed atomic force microscope for studying biological macromolecules.

The atomic force microscope (AFM) is a powerful tool for imaging individual biological molecules attached to a substrate and placed in aqueous solution. At present, however, it is limited by the speed at which it can successively record highly resolved images. We sought to increase markedly the scan speed of the AFM, so that in the future it can be used to study the dynamic behavior of biomolecules. For this purpose, we have developed a high-speed scanner, free of resonant vibrations up to 60 kHz, small cantilevers with high resonance frequencies (450-650 kHz) and small spring constants (150-280 pN/nm), an objective-lens type of deflection detection device, and several electronic devices of wide bandwidth. Integration of these various devices has produced an AFM that can capture a 100 x 100 pixel(2) image within 80 ms and therefore can generate a movie consisting of many successive images (80-ms intervals) of a sample in aqueous solution. This is demonstrated by imaging myosin V molecules moving on mica (see http://www.s.kanazawa-u.ac.jp/phys/biophys/bmv_movie.htm).

Animals↗

PubMed2001

Infiltration of canonical Vgamma4/Vdelta1 gammadelta T cells in an adriamycin-induced progressive renal failure model.

We have previously reported an infiltration of renal interstitial gammadelta T cells in Adriamycin-induced progressive glomerulosclerosis in the rat kidney. The TCR repertoire and sequences used by these gammadelta T cells have now been studied. Two injections of Adriamycin 14 days apart caused segmental glomerulosclerosis, massive interstitial infiltration of mononuclear cells, and end-stage renal failure. Flow cytometry of lymphocyte subpopulations with Abs to CD3, the gammadelta TCR, and the alphabeta TCR showed that gammadelta T cells as a proportion of CD3(+) cells were increased in Adriamycin-treated kidneys (8.5 +/- 5.4%), but not in lymph nodes (1.3 +/- 0.4%). A semiquantitative score of glomerular damage (r = 0.65; p < 0.01) and creatinine (r = 0.62; p < 0.01) correlated significantly with the presence of gammadelta T cells. TCR Vgamma repertoire analysis by RT-PCR and Southern blotting showed that Vgamma2 was the dominant subfamily in lymph nodes, whereas Vgamma4 became the predominant subfamily in advanced stages of the rat Adriamycin-treated kidney. Sequencing of the Vgamma4-Jgamma junctional region showed an invariant sequence. The amino acid sequence of the junctional region of the Vgamma4 TCR was the same as the reported mouse canonical Vgamma4 TCR sequence. Analysis of the kidney Vdelta repertoire showed dominant expression of Vdelta1, and sequencing again revealed the selective expression of a canonical Vdelta1 gene. Semiquantitative RT-PCR for cytokine gene expression showed that gammadelta T cells from the kidneys expressed TGF-beta, but not IL-4, IL-10, or IFN-gamma. These results suggest that the predominant gammadelta T cells in the Adriamycin kidney use an invariant Vgamma4/Vdelta1 receptor.

Animals↗

PubMed2001

Involvement of the interaction between p21 and proliferating cell nuclear antigen for the maintenance of G2/M arrest after DNA damage.

Although a major effect of p21, a cyclin-dependent kinase inhibitor, is considered to be exerted during G(1) phase of the cell cycle, p21 gene knock-out studies suggested its involvement in G(2)/M checkpoint as well. Here we demonstrate evidence that p21 is required for the cell cycle arrest at G(2) upon DNA damage. We found that expression of wild-type p21 (p21(WT)), not mutant p21 (p21(PCNA-)) lacking the interaction with proliferating cell nuclear antigen (PCNA), caused G(2) cell cycle arrest in p53-deficient DLD1 colon cancer cell line after the DNA damage by treatment with cis-diamminedichloroplatinum (II). We also found that p21(WT) was associated with Cdc2/cyclin B1 together with PCNA. Furthermore, coimmunoprecipitation experiments revealed that PCNA interacted with Cdc25C at the G(2)/M transition, and this interaction was abolished when p21(WT) was expressed presumably due to the competition between p21(WT) and Cdc25C in the binding to PCNA. These findings suggest that p21 plays a regulatory role in the maintenance of cell cycle arrest at G(2) by blocking the interaction of Cdc25C with PCNA.

Amino Acid Sequence↗

PubMed2001

Probable Langevin-like director reorientation in an interface-induced disordered SmC*-like state of liquid crystals characterized by frustration between ferro- and antiferroelectricity.

To clarify the thresholdless, hysteresis free V-shaped switching due to frustration between ferro- and antiferroelectricity, we have studied a prototype binary mixture system. The apparent orientational order parameters, and , obtained from polarized Raman scattering in thin homogeneous cells indicate that substrate interfaces induce some randomization of local in-plane directors at the tip of the V. Their correlation lengths, xi( parallel) approximately 3.5 nm and xi( perpendicular) approximately 75 nm, have been estimated by assuming the Langevin-like reorientation. Because of the much shorter xi(parallel) and xi(perpendicular) than the visible light wavelength, the switching process looks uniform.

Journal Article↗

PubMed2001

"Norwalk-like viruses". Public health consequences and outbreak management.

"Norwalk-like viruses" (NLVs) cause outbreaks of gastroenteritis and are spread frequently through contaminated food or water. Molecular diagnostics now enables detecting viruses in clinical and environmental specimens, linking of NLV strains causing outbreaks in multiple geographic locations, and tracing them to their sources in contaminated food or water. This report reviews recent advances in NLV detection and provides guidelines and recommendations for investigating NLV-related outbreaks, including specimen collection and disease prevention and control. This report also updates information provided in CDC's previously published, Viral Agents of Gastroenteritis: Public Health Importance and Outbreak Management (MMWR 1990;39 [No. RR-5]: 1-24). These CDC recommendations are intended for public health professionals who investigate outbreaks of acute gastroenteritis but could be useful in academic and research settings as well.

Caliciviridae Infections↗

PubMed2001

Gastroenteritis viruses: an overview.

Acute gastroenteritis is among the most common illnesses of humankind, and its associated morbidity and mortality are greatest among those at the extremes of age, children and the elderly. In developing countries, gastroenteritis is a common cause of death in children < 5 years that can be linked to a wide variety of pathogens. In developed countries, while deaths from diarrhoea are less common, much illness leads to hospitalization or doctor visits. Much of the gastroenteritis in children is caused by viruses belonging to four distinct families--rotaviruses, caliciviruses, astroviruses and adenoviruses. Other viruses, such as the toroviruses, picobirnaviruses, picornavirus (the Aichi virus), and enterovirus 22, may play a role as well. Viral gastroenteritis occurs with two epidemiologic patterns, diarrhoea that is endemic in children and outbreaks that affect people of all ages. Viral diarrhoea in children is caused by group A rotaviruses, enteric adenoviruses, astroviruses and the caliciviruses; the illness affects all children worldwide in the first few years of life regardless of their level of hygiene, quality of water, food or sanitation, or type of behaviour. For all but perhaps the caliciviruses, these infections provide immunity from severe disease upon reinfection. Epidemic viral diarrhoea is caused primarily by the Norwalk-like virus genus of the caliciviruses. These viruses affect people of all ages, are often transmitted by faecally contaminated food or water, and are therefore subject to control by public health measures. The tremendous antigenic diversity of caliciviruses and short-lived immunity to infection permit repeated episodes throughout life. In the past decade, the molecular characterization of many of these gastroenteritis viruses has led to advances both in our understanding of the pathogens themselves and in development of a new generation of diagnostics. Application of these more sensitive methods to detect and characterize individual agents is just beginning, but has already opened up new avenues to reassess their disease burden, examine their molecular epidemiology, and consider new directions for their prevention and control through vaccination, improvements in food and water quality and sanitary practices.

Adenoviruses, Human↗

PubMed2001

Total gastrectomy with distal pancreatectomy and splenectomy for advanced gastric cancer.

BACKGROUND: Pancreaticosplenectomy (PS) is often performed simultaneously with total gastrectomy (TG) to facilitate dissection of the lymph nodes around the splenic artery and splenic hilus. To evaluate the effects of PS on survival, a retrospective study was performed. METHODS: Various clinicopathological factors influencing lymph node metastasis around the splenic hilus (No. 10) and the splenic artery (No. 11) were studied retrospectively in the upper or middle third of advanced gastric cancer patients who underwent TG with PS. The postoperative morbidity, mortality, and survival rate of patients who underwent TG with PS (the TG with PS group) were compared with those of patients who underwent TG alone (the TG-alone group). RESULTS: Tumor size larger than 41 mm and lymph node No. 2 metastasis were independently correlated with lymph node No. 10 and No. 11 metastasis. The mortality rate was similar, but the morbidity rate was significantly higher in the TG with PS group. In the patients with stage I and III, there was no significant difference between the two groups, but in the patients with stage II, the TG-alone group was significantly better than the TG with PS group (P = 0.0400). CONCLUSIONS: Combined PS with TG should never be performed as the standard surgical procedure for every stage of gastric cancer, especially stage II.

Adult↗

PubMed2001

Left hemihepatectomy with microsurgical reconstruction of the right-sided hepatic vasculature. A strategy for preserving hepatic function in patients with proximal bile duct cancer.

BACKGROUND: Right hemihepatectomy (RH) for proximal bile duct cancer occasionally results in liver failure. We report the feasibility of left hemihepatectomy (LH) with vascular reconstruction (VR) of the right-sided hilar vessels to preserve hepatic reserve. METHODS: Among 110 patients with proximal bile duct cancer (PBC) treated between January 1980 and December 1998, 11 patients underwent LH with VR of eight portal veins and nine hepatic arteries, and 14 underwent RH with VR of four portal veins and one hepatic artery. Microsurgical techniques were used in 80% (8/10) of the hepatic arterial reconstructions. RESULTS: Although operation time was significantly longer in the LH group, hospital mortality, blood loss and incidence of histologically cancer positive margin at the bilioenteric anastomotic site were similar in the two groups. Peak serum liver enzyme concentration was significantly higher in the LH group with longer inflow occlusion time, whereas peak serum total bilirubin concentration was significantly higher in the RH group, which had smaller liver remnant. No liver abscess occurred in any patients who underwent microvascular reconstructions. The cumulative survival of the LH group was worse than that of the RH group, in which the proportion of vascular invasion was lower, but not significantly. CONCLUSION: LH with right-sided microvascular reconstruction is technically possible and a feasible option when RH is likely to result in postoperative liver failure.

Bile Duct Neoplasms↗

PubMed2001

Genetic classification of "Sapporo-like viruses".

"Sapporo-like viruses" (SLVs) and "Norwalk-like viruses" (NLVs) are an important cause of acute gastroenteritis in humans. While NLVs have been genetically classified into three major genetic groups consisting of 17 genetic subgroups, a classification of SLVs into comparable genetic groups remains to be determined. In an attempt to classify both SLVs and NLVs uniformly, the sequences of 2 SLV strains newly detected from French infants were analysed together with the published sequences of 9 SLV and 19 NLV strains. Distance and phylogenetic analyses were conducted on the sequences of the capsid gene, RNA polymerase gene, 3' open reading frame (3'ORF), ORF overlapping the capsid gene, and 3' untranslated region (3'UTR). The histogram showing frequency distribution of pairwise distances and the topology of the phylogenetic tree demonstrated that SLVs and NLVs could be classified uniformly on the basis of the entire capsid sequences and that the 11 SLV strains could be genetically classified into 3 major genetic groups, genogroups I, II and III, comprised of 5 genetic subgroups. The differentiation of the 11 SLV strains into these genetic groups was also maintained in the 4 remaining genome regions, while the sequences at the junction between the RNA polymerase and capsid genes were shown to be genogroup-specific.

3' Untranslated Regions↗

PubMed2001

Link between the enzymatic kinetics and mechanical behavior in an actomyosin motor.

We have attempted to link the solution actomyosin ATPase with the mechanical properties of in vitro actin filament sliding over heavy meromyosin. To accomplish this we perturbed the system by altering the substrate with various NTPs and divalent cations, and by altering ionic strength. A wide variety of enzymatic and mechanical measurements were made under very similar solution conditions. Excellent correlations between the mechanical and enzymatic quantities were revealed. Analysis of these correlations based on a force-balance model led us to two fundamental equations, which can be described approximately as follows: the maximum sliding velocity is proportional to square root of V(max)K(m)(A), where K(m)(A) is the actin concentration at which the substrate turnover rate is half of its maximum (V(max)). The active force generated by a cross-bridge under no external load or under a small external load is proportional to square root of V(max)/K(m)(A). The equations successfully accounted for the correlations observed in the present study and observations in other laboratories.

Acid Anhydride Hydrolases↗

PubMed2001

Highly diverse TTV population in infants and their mothers.

Infants born to serum HCV-positive 12 mothers were enrolled in the study. Nucleotide sequences amplified by primers deduced from a noncoding region were compared between mothers and their infants. The rates for detection of serum TTV in 12 mothers and their infants were 10/12 (83%) and 9/12 (75%), respectively. Serum TTV DNA was not detected in any infant at 1 month of age, but was detected for the first time between 1.5 and 8 months after birth. Positivity persisted thereafter throughout the follow-up period. In seven randomly selected mother-infant pairs, intrahost TTV heterogeneity was lower in infants than in mothers. Furthermore, one of seven mother-infant pairs showed a high degree of similarity (98.7-100%) in all clones, while in four infants, all nucleotide sequences differed by >10% from those of their mothers. However, the degree of homology in the two mother-infant pairs was 89-98.7% in family 2 and 88.1-99.4% in family 5. In the present study, with only one exception, it was shown that TTV from infants is not identical to TTV from mothers. The mechanism is discussed briefly in this paper.

DNA Virus Infections↗

PubMed2001

Enantioselective synthesis and absolute configuration of (-)-1-(benzofuran-2-yl)-2-propylaminopentane, ((-)-BPAP), a highly potent and selective catecholaminergic activity enhancer.

Enantioselective synthesis and absolute configuration of (-)-1-(benzofuran-2-yl)-2-propylaminopentane ((-)-BPAP), which is a highly potent and selective catecholaminergic activity enhancer (CAE) substance, are described. The synthetic approach consists of the coupling reaction of benzofuran with (R)-N-tosyl-2-propylazirizine or (R)-N-methoxy-N-methylnorvaliamide, followed by appropriate modifications of the resulting coupling products. As the results, (-)-BPAP turned out to have the R configuration, which was finally confirmed by X-ray crystallographic analysis.

Azirines↗

PubMed2001

Histopathology of cryptococcosis and other fungal infections in patients with acquired immunodeficiency syndrome.

OBJECTIVE: To gain insight into the histopathologic characteristics of fungal infection in acquired immunodeficiency syndrome (AIDS). METHODS: A review was conducted of the histopathology for 162 patients with evident fungal infection. RESULTS: The microscopic appearance of esophageal candidiasis that was common in patients with single organ involvement revealed necrotic debris containing proliferating hyphae at the site of mucosal erosions without fungal invasion of underlying tissue. The incidence of oral and esophageal candidiasis was followed by that of pulmonary aspergillosis and Candida infection. Eighteen patients had generalized cryptococcosis, representing the commonest generalized fungal disease. The essential histologic features of the disease consisted of yeast cell proliferation with a histiocytic response, but only minor lymphocytic and neutrophilic components. This was different from the manifestations of both Candida and Aspergillus infections. The two histologic patterns recognized in the pulmonary cryptococcal lesions could be graded with respect to the degree and type of inflammatory reaction. The milder one consisted of small scattered foci of intra-alveolar cryptococcal proliferation with a histiocytic response. Another pattern involved massive cryptococcal infection, which might be simply more extensive than that in the former. Capillary involvement of alveolar septa was an important common finding in all 18 patients.

Acquired Immunodeficiency Syndrome↗