Search PubMed⌕ Search

Biomedical subjects

T Ando

Publications and source records attributed to T Ando.

At least 127 records · Page 7Linked to original sources
PubMed2000

Restriction-modification system differences in Helicobacter pylori are a barrier to interstrain plasmid transfer.

Helicobacter pylori cells are naturally competent for the uptake of both plasmid and chromosomal DNA. However, we demonstrate that there are strong barriers to transformation of H. pylori strains by plasmids derived from unrelated strains. We sought to determine the molecular mechanisms underlying these barriers. Transformation efficiency was assessed using pHP1, an Escherichia coli-H. pylori shuttle vector conferring kanamycin resistance. Transformation of 33 H. pylori strains was attempted with pHP1 purified from either E. coli or H. pylori, and was successfully introduced into only 11 strains. Digestion of H. pylori chromosomes with different restriction endonucleases (REs) showed that DNA methylation patterns vary substantially among strains. The strain most easily transformed, JP26, was found to have extremely low endogenous RE activity and to lack a restriction-modification (R-M) system, homologous to MboI, which is highly conserved among H. pylori strains. When we introduced this system to JP26, pHP1 from MboI.M+ JP26, but not from wild-type JP26, transformed MboI R-M+ JP26 and heterologous MboI R-M+ wild-type H. pylori strains. Parallel studies with pHP1 from dam+ and dam- E. coli strains confirmed these findings. These data indicate that the endogenous REs of H. pylori strains represent a critical barrier to interstrain plasmid transfer among H. pylori.

Chromobox Protein Homolog 5↗
PubMed2000

Clinicopathologic analysis of stage II-III hepatocellular carcinoma showing early massive recurrence after liver resection.

BACKGROUND AND AIMS: Prognosis after hepatectomy for hepatocellular carcinoma (HCC) has been improved by progress in the evaluation of hepatic functional reserve, surgical techniques and perioperative management. However, even when curative resection is performed at a relatively early stage, a considerable number of patients develop early intrahepatic and/or extrahepatic recurrence postoperatively. This study analyzed the clinicopathologic features of HCC with early recurrence. METHODS: We reviewed records of 513 consecutive patients who had undergone liver resection for HCC. There were 48 deaths within a year after surgery from recurrence, including 21 patients with stage II or III HCC (group I). Clinicopathologic parameters of group I patients were compared with those of 188 patients (group II) who developed recurrence following resection of stage II or III HCC and died more than 1 year after surgery. RESULTS: On univariate analysis, age, tumor diameter (phi), alpha-fetoprotein (AFP):phi and protein induced by vitamin K absence or antagonist II (PIVKA-II):phi were significantly greater in group I than in group II. Macroscopic portal vein invasion, microscopic vascular invasion, intrahepatic metastasis, poor differentiation, pleomorphism, sarcomatous change, vascular lake, and angiographic condensed pooling were more frequently observed in group I than group II. Five independent determinants were selected by multivariate analysis: AFP:phi, histologic pleomorphism, sarcomatous change, vascular lake and angiographic condensed pooling. CONCLUSIONS: Highly malignant HCC with extremely poor prognosis exhibits peculiar clinicopathologic characteristics, particularly histologic immaturity, and can be predicted by preoperative indicators such as markedly elevated tumor marker concentrations and condensed pooling on angiography.

Aged↗
PubMed2000

Pulmonary tuberculosis with unusual cystic change in an immunocompromised host.

We present a rare case of upper zone cystic change of the lung with disseminated tuberculosis of a non-smoking 30-year-old immunocompromised male. He suffered from repeated pneumothorax. The basic pathological feature of video-assisted thoracoscopic lung biopsy revealed granulomatous involvement in the respiratory bronchioles with poorly developed epithelioid cells and disruption of elastic fibers. Electron microscopy demonstrated a decrease in elastic fibers and disruption of the epithelial basement membrane of the respiratory bronchiole and no Langerhans cells in the lesion. Autopsy of the lung revealed centroacinar distribution of multiple cystic lesions in the bilateral upper lobe. Almost all cystic walls showed loss of elastic fibers and cysts frequently involved the respiratory and terminal bronchioles, alveolar ducts and, occasionally, alveoli. Some larger cystic lesions revealed communication to the bronchi. The cystic changes in this case of pulmonary tuberculosis may be caused by a check-valve mechanism due to granulomatous involvement of the bronchioles and also by excavation of caseous necrotic material by draining bronchi.

Adult↗
PubMed2000

Gastric metaplasia in the duodenal bulb shows increased mucosal interleukin-8 activity in Helicobacter pylori-positive duodenal ulcer patients.

BACKGROUND: Although increased levels of interleukin (IL)-8 are known to be associated with infiltration of neutrophils in the gastric mucosa with Helicobacter pylori infection, no study has investigated the relationship between local IL-8 levels and neutrophil infiltration in the duodenal mucosa of patients with duodenal ulcer (DU). METHODS: Duodenal mucosal biopsy specimens with and without gastric metaplasia (GM) were obtained from patients with DU and controls with an endoscopic methylene blue (MB) staining method. Levels of IL-8 secreted in the organ cultures of biopsy specimens were measured with an enzyme-linked immunosorbent assay. The number of myeloperoxidase-positive neutrophils infiltrating the lamina propria was determined in immunohistochemically stained tissue sections. RESULTS: Histologic assessment showed that there was a strong correlation between the absence of endoscopic MB staining and the extent of GM. The levels of IL-8 in both duodenal and antral mucosal tissues were significantly higher in patients with H. pylori infection than in those without infection. In patients with DU the duodenal mucosal tissues with GM (MB-unstained mucosa) showed significantly higher levels of IL-8 than those without GM (MB-stained mucosa) or the antral mucosa. The number of neutrophils showed similar variations among DU and control patients with a positive correlation with IL-8 activity. The levels of IL-8 and the number of neutrophils decreased after H. pylori eradication in both duodenal and antral mucosal tissues, and these changes were more remarkable in the duodenal mucosal tissues with GM. CONCLUSIONS: Increased IL-8 activity in the duodenal mucosa with GM may be important for ulcerogenesis in H. pylori-positive DU patients.

Adult↗
PubMed2000

Cold weather seasonality of gastroenteritis associated with Norwalk-like viruses.

Norwalk-like viruses (NLVs) are the most common cause of acute nonbacterial gastroenteritis in adults, but little is known about their seasonality. The lack of specific diagnostic tools impeded study of these viruses in the past, and surveys using electron microscopy often grouped NLVs with other unrelated viruses. A search of the scientific literature found eight surveys of gastroenteritis, which were conducted for at least 1 year, that specifically identified NLVs. Unpublished data from laboratories of 4 NLV researchers were also used. These surveys, which were conducted in eight countries, reported sporadic cases and outbreaks of NLV-associated gastroenteritis among all age groups. The monthly occurrence of these cases and outbreaks was plotted, and while transmission occurred year-round in most surveys, a cold weather peak was demonstrated in 11 of the 12 studies. This key epidemiologic feature of the viruses has important implications concerning their mode of transmission and for understanding the etiology of acute gastroenteritis in adults.

Adult↗
PubMed2000

The epidemiology of enteric caliciviruses from humans: a reassessment using new diagnostics.

In the United States, acute gastroenteritis is one of the most commonly noted illnesses on hospital discharge records and death certificates, yet few of these cases have an etiologic diagnosis. The application of new molecular diagnostic methods has shown caliciviruses (previously referred to as the Norwalk family of viruses or small round structured viruses) to be the most common cause of acute gastroenteritis (AGE) outbreaks in the United States, and they may emerge as a common cause of sporadic cases of AGE among both children and adults. Novel molecular methods have permitted outbreak strains to be traced back to their common source and have led to the first identification of virus in implicated vehicles of infection-water, shellfish, and foods contaminated both at their source and by food handlers. The broad application of these methods to routine diagnosis in hospitals and public health laboratories is advancing our appreciation of the full burden of calicivirus-associated diarrhea, and it is opening new avenues for its prevention and control.

Acute Disease↗
PubMed2000

Genetic classification of "Norwalk-like viruses..

Reverse transcription-polymerase chain reaction has been used worldwide for the diagnosis of Norwalk-like virus (NLV) infection, yet a commonly accepted genetic classification scheme has not been established. Amino acid sequences from four regions of open-reading frame 2 (ORF2) were used to analyze 101 NLV strains, including 2 bovine strains. On the basis of this analysis, a genetic classification scheme is proposed that differentiates 99 human strains into 2 major genetic groups consisting of 5 and 10 genetic clusters, respectively. The 2 bovine strains constitute a newly defined third major genetic group composed of 2 putative clusters represented by each strain. This classification scheme is well supported by the analysis of the entire ORF2 sequences from 38 strains selected to represent the genetic diversity of the human strains used above. This scheme should provide a firm scientific basis for the unified classification of NLV strains detected around the world.

Amino Acid Sequence↗
PubMed2000

Taxonomy of the caliciviruses.

The International Committee on Taxonomy of Viruses (ICTV) has recently approved several proposals submitted by the present Caliciviridae Study Group. These proposals include the division of the family into 4 new genera designated Lagovirus, Vesivirus, "Norwalk-like viruses (NLVs), and "Sapporo-like viruses (SLVs); the latter 2 genera were assigned temporary names until acceptable names can be determined by the scientific community. The genera have been further divided into the following species: Feline calicivirus and Vesicular exanthema of swine virus (genus Vesivirus), Rabbit hemorrhagic disease virus and European brown hare syndrome virus (genus Lagovirus), Norwalk virus (genus NLV), and Sapporo virus (genus SLV). In addition, the ICTV approved a proposal to remove the hepatitis E virus from the Caliciviridae into an "unassigned classification status.

Animals↗
PubMed2000

Treatment with propylthiouracil is associated with appearance of antineutrophil cytoplasmic antibodies in some patients with Graves' disease.

The use of propylthiouracil (PTU) for the treatment of Graves' disease is associated with few adverse effects such as skin eruptions, liver dysfunction, and agranulocytosis. Furthermore, recent studies described the development of antineutrophil cytoplasmic antibody (ANCA)-related glomerulonephritis and vasculitis in patients treated with PTU. Here we investigated whether PTU therapy per se is associated with the appearance of ANCA in patients with Graves' disease. We analyzed 119 serum samples from 117 patients with Graves' disease treated with either PTU (n = 56), or methimazole (MMI) (n = 21), as well as untreated patients (n = 42). Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA were tested by enzyme-linked immunosorbent assay (ELISA) kits. MPO-ANCA was negative in all patients treated with MMI therapy and untreated patients. However, MPO-ANCA was detected in 21 (37.5%) of 56 patients treated with PTU therapy. Furthermore, two patients who were negative for MPO-ANCA became positive after PTU therapy. The proportion of patients positive for MPO-ANCA increased with the prolongation of PTU therapy, but did not correlate with age, gender, and positive antithyroperoxidase (TPO) antibody. Among 21 MPO-ANCA positive patients, 12 had no symptoms, but 9 patients complained of myalgia, arthralgia, or common cold like symptoms after the appearance of MPO-ANCA. Three patients developed agranulocytosis or granulocytopenia, but none showed abnormal urinary findings. Our results suggest that PTU per se is associated with the production of MPO-ANCA in patients with Graves' disease.

Adult↗
PubMed2000

Anaplastic changes associated with p53 gene mutation in differentiated thyroid carcinoma after insufficient radioactive iodine (131I) therapy.

Thirty-two patients with differentiated thyroid carcinomas with distant metastasis were examined using a radioactive iodine (131I) tracer dose prior to 131I therapy and followed up for 10 years or until death (whichever occurred first). Nineteen patients who received 131I therapy had an accumulation of 131I in the metastases (group I) and 15 of those patients were alive more than 10 years after the first 131I treatment. In contrast, all 13 patients in whom the metastases did not show accumulation of 131I died within 10 years. Of the latter group, eight patients had received 131I therapy (group II), four of whom died with anaplastic changes within 5 years of treatment. p53 gene mutation was identified by immunohistochemistry in primary thyroid carcinoma tissue from patients with anaplastic changes that were evident during total thyroidectomy. Five patients did not receive 131I therapy (group III), of whom one, who also had a p53 gene mutation in the original tumor, died with anaplastic change 10 years after thyroidectomy. Seven patients in group I had p53 gene mutations in their thyroid carcinoma tissues, but none showed anaplastic changes. Our results suggest that 131I therapy may be useful for patients with distant metastases, with or without p53 gene mutations, which show accumulation of 131I from tracer and therapeutic doses. In contrast, 131I therapy is apparently not effective in patients who do not show sufficient accumulation of 131I, but rather, may cause early anaplastic changes with a p53 gene mutation.

Adult↗
PubMed2000

[Deep-seated mycosis in patients with solid-organ transplantation--a study of autopsied cases in the United States].

Autopsies with solid-organ trans plantation (SOT) in UCLA Medical Center were reviewed, especially focussing on the deep-seated fungal infection and the incidence of fungal infections, causative fungi, and organs involved were evaluated. Deep-stated fungal infections were demonstrated in 21.0% of the patients with SOT. The incidence of fungal infections were 26.1% in kidney transplantation, which was the highest rate in SOT autopsies we reviewed, 25.0% in liver transplantation, 14.3% in lung transplantation, and 13.2% in heart transplantation. And the most common causative fungi were Aspergillus species, seen in 70.6% of SOT autopsies. In contrast, Candida species were observed in 25.5%. In addition, the incidence of deep-seated mycosis has been increasing since 1992, this was parallel to the increase of aspergillosis, most of which were found as a generalized spreading. In contrast, candidal lesions, were almost limited to the digestive tracts. The above suggests that from this standpoint, improvement of prophylactic and therapeutic technique against aspergillosis is the greatest problem in deep-seated mycosis in SOT patients.

Adolescent↗
PubMed2000

Anti-CagA immunoglobulin G responses correlate with interleukin-8 induction in human gastric mucosal biopsy culture.

Helicobacter pylori persists in the human stomach despite eliciting both cellular and humoral immune responses and inducing proinflammatory cytokines. To determine whether local humoral and cytokine responses are related to each other and to histologic responses, we studied 66 Japanese patients who underwent gastroscopy. Using specific enzyme-linked immunosorbent assays, we examined gastric antral mucosal-organ biopsy culture supernatants to assess interleukin-6 (IL-6) and interleukin-8 (IL-8) levels and antibody responses to H. pylori whole-cell antigens CagA, HspA, and HspB. Of the patients studied, 11 were H. pylori negative and 55 were H. pylori positive; by PCR, all strains were cagA(+). As expected, compared to H. pylori-negative patients, H. pylori-positive patients had significantly higher humoral responses to all H. pylori antigens and had higher IL-8 (47.8+/-3.5 versus 10.1+/-4.3 ng/mg of biopsy protein; P<0.001) and IL-6 levels (2.8+/-0.3 versus 0.26+/-0.2 ng/mg of protein; P<0.001). Among the H. pylori-positive patients, supernatant anti-CagA immunoglobulin G (IgG) levels were significantly associated with H. pylori density (P<0.005) and neutrophil infiltration (P<0.005) scores. Anti-CagA immunoglobulin A levels were correlated with intestinal metaplasia (P<0.05). Mononuclear cell infiltration scores were significantly associated with supernatant IL-6 levels (P<0.005) and with IgG responses to whole-cell antigens (P<0.05). Supernatant IL-8 levels were significantly associated with anti-CagA IgG (r = 0.75, P<0.001). Anti-CagA responses correlated with neutrophil infiltration, intestinal metaplasia, H. pylori density, and IL-8 levels, suggesting that the absolute levels of these antibodies may be markers for gastric inflammation and premalignant changes in individual hosts.

Antibodies, Bacterial↗
PubMed2000

Bacterial translocation can increase plasma corticosterone and brain catecholamine and indoleamine metabolism.

The potential contribution of stress-induced bacterial translocation to the activation of the hypothalamo-pituitary-adrenocortical (HPA) axis and brain biogenic amines was assessed. Mice were restrained for various periods, and brain concentrations of tryptophan, catecholamines, serotonin, and their metabolites, plasma corticosterone, and the translocation of viable bacteria from the gastrointestinal tract to the mesenteric lymph nodes, spleen, and liver were measured. Restraint induced the translocation of indigenous gram-positive bacteria in only a small proportion of animals, but translocation of gram-negative bacteria did not occur. Restraint induced short-lived increases in plasma corticosterone and brain amine metabolism, whereas bacterial translocation was slower and persisted long after the HPA axis and neurochemical responses had dissipated. When mice were infected with Salmonella typhimurium, spontaneous translocation occurred and plasma corticosterone, interleukin-6 concentrations, and brain catecholamine and indoleamine metabolism were elevated. These findings indicate that the translocation of indigenous gastrointestinal bacteria did not contribute to the HPA axis and neurochemical changes induced by restraint. However, translocation of nonindigenous S. typhimurium with or without restraint did induce HPA and neurochemical responses.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2000

Helicobacter pylori-associated gastric ulcer exhibits enhanced mucosal chemokine activity at the ulcer site.

BACKGROUND AND AIM: Although mucosal alpha- and beta-chemokines are considered to be involved in the pathogenesis of Helicobacter pylori-associated gastritis, little is known how these chemokines are related to the ulcerogenesis in peptic ulcer patients. We examined the levels of interleukin (IL)-8 and macrophage inflammatory protein-1alpha (MIP-1alpha) in organ cultures and the numbers of inflammatory cells infiltrating the lamina propria by using the mucosal tissues obtained from gastric ulcer (GU) patients with and without H. pylori infection. METHODS: Levels of IL-8 and MIP-1alpha secreted in organ cultures were measured by an enzyme-linked immunosorbent assay. Numbers of myeloperoxidase-positive neutrophils, CD68-positive macrophages, and mononuclear cells were determined in tissue sections. RESULTS: The mucosal tissues of both the gastric antrum and the ulcer site obtained from patients with H. pylori-positive GU showed significantly higher levels of IL-8 and MIP-1alpha and increased numbers of inflammatory cells compared with the corresponding mucosal tissues from those with H. pylori-negative GU or the antral mucosal tissues from H. pylori-negative controls. When the values were compared between the mucosal tissues from the gastric antrum and those from the ulcer site, the latter group of tissues showed significantly higher levels of IL-8 and MIP-1alpha and increased numbers of neutrophils and macrophages than the former group regardless of its healing process in patients with H. pylori-positive GU. CONCLUSION: Mucosal alpha- and beta-chemokines may be important to the ulcerogenesis in H. pylori-associated GU disease.

Adult↗