Musical obsessions or hallucinations?
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Adult↗
Biomedical subjects
N Ikemura
Publications and source records attributed to N Ikemura.
SSRI-TCA combination in the treatment of resistant depression.
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Antidepressive Agents, Tricyclic↗
RNA editing-like phenomenon in paramyxovirus V gene mRNA observed in insect cells infected with a recombinant baculovirus.
The V gene of the paramyxovirus human parainfluenza virus type 2 (hPIV2) is transcribed into both V and P mRNA. The V mRNA is a faithful transcript of the V gene; however, the P mRNA is transcribed by an RNA-editing mechanism in hPIV2-infected mammalian cells. Recombinant baculoviruses (rBV) were constructed containing the wild-type V gene, which has seven G residues at its editing site, and a manipulated V gene with ten G residues at its editing site. A small amount of the P protein was synthesized, in addition to the V protein, when the wild-type V gene was expressed in rBV-infected insect cells. Furthermore, synthesis of the P protein increased when rBV containing the manipulated V gene was used to infect insect cells. Both the P and V proteins were detected after in vitro translation of mRNA from rBV-infected cells. Moreover, G-residue insertions and a deletion were detected in mRNA. Since the P protein was not detected after in vitro translation of V RNA that had been transcribed in vitro by T7 RNA polymerase, these results suggest that the non-encoded G residues were inserted and deleted during transcription in insect cells. This RNA editing-like phenomenon and the implications of the length of the G cluster are discussed.
Animals↗
Growth inhibition of Helicobacter pylori by a polyamine synthesis inhibitor, methylglyoxal bis(cyclopentylamidinohydrazone).
The anti-proliferative effect of methylglyoxal bis(cyclopentylamidino-hydrazone) (MGBCP), a multi-enzyme inhibitor of polyamine biosynthesis, on the growth of Helicobacter pylori was investigated. MGBCP inhibited the cell growth of H. pylori in a dose-dependent manner. The inhibition was partially reversed by the addition of spermidine. Synthesis of macromolecules, DNA, RNA and protein, was inhibited in the spermidine-depleted H. pylori cells. These findings suggest that MGBCP exhibits an anti-proliferative effect on H. pylori by suppression of macromolecule synthesis.
Anti-Bacterial Agents↗
Helicobacter pylori inhibits the secretory activity of gastric parietal cells in patients with chronic gastritis. An ultrastructural study.
BACKGROUND: Previous in vitro studies suggested that Helicobacter pylori may inhibit the acid secretion of gastric parietal cells. The aim of this study was to investigate ultrastructurally the influence of H. pylori infection on the gastric parietal cell function in vivo. METHODS: This study comprised 28 patients with chronic gastritis. Biopsy specimens were taken from the gastric body in all cases and examined by electron microscopy. Gastric parietal cells were counted in each ultrathin section and classified into secretory and non-secretory types. The pH of the gastric juice was also measured in all patients. RESULTS: The number of parietal cells in the secretory phase was significantly lower in H. pylori-infected (n = 16) patients than in those (n = 12) without H. pylori infection. The intragastric pH was significantly higher in patients with H. pylori-associated gastritis than in those without H. pylori infection. Parietal cells in secretory phase tended to decrease in proportion to the activity of the gastric mucosal inflammation. CONCLUSIONS: The results of this investigation suggests that H. pylori-associated gastritis is related to a decreased secretory activity of the gastric parietal cells.
Biopsy↗
Gastric juice levels of lactoferrin and Helicobacter pylori infection.
BACKGROUND: Recently, in vitro studies suggested that lactoferrin (Lf) might play an important role in the physiopathology of Helicobacter pylori-associated gastritis. However, whether Lf is present in the gastric juice and its relationship with H. pylori infection have not as yet been reported. In the present investigation the presence of Lf in gastric juice and its correlation with H. pylori infection were assessed. METHODS: This study comprised 30 H. pylori-positive and 14-negative patients with chronic gastritis. Gastric juice levels of Lf were measured with enzyme-linked immunoassays. Gastric juice concentration of Lf was also investigated in accordance with the histologic findings of biopsy specimens in the gastric body and antrum. RESULTS: Lf concentration in gastric juice was significantly higher in H. pylori-positive than in -negative patients (P = 0.033). The pH values are known to influence the levels of Lf. However, intragastric Lf levels were also significantly increased in H. pylori-positive patients as compared with H. pylori-negative patients after correcting the Lf levels for pH values (P = 0.029) or after adjusting the pH values of the gastric juice with NaHCO3 solution in both groups of patients (P = 0.0007). In addition, the gastric juice levels of Lf correlated significantly with the gastric mucosal concentrations of Lf in the gastric body (P < 0.005, r = 0.568) and the antrum (P < 0.05, r = 0.401). CONCLUSIONS: This study showed for the first time that Lf is present in gastric juice and that it correlates with H. pylori infection. Lf may constitute a good marker for H. pylori-associated gastritis. Although correlation does not prove causation, this study suggests that Lf might play an important role in the physiopathology of H. pylori-associated gastritis.
Biomarkers↗
Relation of lactoferrin levels in gastric mucosa with Helicobacter pylori infection and with the degree of gastric inflammation.
OBJECTIVES: Lactoferrin (Lf) is an iron-binding glycoprotein present in milk, lacrimae, saliva, and gastroduodenal secretions. In vitro studies disclosed contradicting results regarding the relation of Lf with Helicobacter pylori (HP) infection. This study aimed to investigate the relationship between the gastric mucosal concentration of Lf and HP infection of the stomach. The relationship of the gastric mucosal level of Lf with the gastric mucosal concentration of interleukin-8 (IL-8) and with the intragastric ammonia levels was also assessed. In addition, the gastric mucosal Lf levels before and after irradication of HP infection were also evaluated. METHODS: This study was composed of 27 HP-positive and 12 HP-negative patients with chronic gastritis. Gastric mucosal biopsy specimens were obtained from all subjects by endoscopy, and the degree of histological inflammatory changes were assessed according to the Sydney system. The gastric mucosal levels of Lf and IL-8 were measured by immunoassays. Assessment of the effect of therapy on the gastric mucosal level of Lf was performed in 10 patients with HP-associated duodenal ulcer. RESULTS: Lf, IL-8, and ammonia levels were significantly higher in patients with HP-positive gastritis compared with those with HP-negative gastritis in both the antrum and the gastric body. Histologically, the degree of inflammatory changes correlated significantly with the Lf levels in the gastric mucosa. Furthermore, the degree of HP colonization was more significant in biopsy samples from the antrum than in those from the corpus of the stomach. The gastric mucosal levels of Lf and IL-8 correlated significantly in the antrum and the gastric body. The ammonia intragastric level significantly correlated with the mucosal Lf level in the antrum and in the gastric body. Therapy significantly decreased the Lf levels in the gastric mucosa of the antrum (p < 0.005) and the gastric body (p < 0.005). CONCLUSION: The results of the present investigation showed, for the first time in vivo, that Lf concentration is increased in the biopsy specimens of patients with HP-related gastritis, and that the levels of Lf correlate significantly with the degree of inflammation of the gastric mucosa. The gastric mucosal level of Lf may constitute an excellent marker of HP infection.
2-Pyridinylmethylsulfinylbenzimidazoles↗
Helicobacter pylori infection in patients with gastric carcinoma in biopsy and surgical resection specimens.
BACKGROUND: The discrepancy between the high seropositivity for Helicobacter pylori (H. pylori) and the low diagnostic yield of H. pylori organism in gastric biopsies of patients with gastric carcinoma has yet to be clarified. The present study attempted to clarify this controversial point by performing a comparative evaluation between the detection rate of H. pylori in biopsy and in surgical specimens. METHODS: The presence of H. pylori in biopsy samples from 50 patients with gastric carcinoma and 50 age-matched controls was evaluated histologically. Six histologic sections were obtained from gastric noncancerous areas and the presence of H. pylori was evaluated in those H. pylori negative patients who underwent gastrectomy. RESULTS: H. pylori was positive in 35 of 50 controls (70%). In biopsy samples, H. pylori was detected in 29 of 37 patients (78.4%) with early gastric carcinoma, 7 of 13 (53.8%) with advanced carcinoma, 16 of 23 (69.6%) with intestinal type of gastric carcinoma, and 20 of 27 (74.1%) with diffuse type of carcinoma. Studies carried out in gastrectomy specimens increased the diagnostic yield of H. pylori to 33 (89.2%), 12 (92.3%), 19 (82.6%), and 26 (96.3%) in patients with early, advanced intestinal, and diffuse types of gastric carcinoma, respectively. Overall, H. pylori was positive in 36 biopsy specimens (72%) and 45 gastrectomy specimens (90%). Namely, the detection of H. pylori infection was significantly higher in patients with gastric carcinoma using gastrectomy specimens than in patients with gastric carcinoma using biopsy specimens only (P < 0.05). CONCLUSIONS: These results indicate that the actual prevalence of H. pylori in patients with gastric carcinoma is considerably higher than that previously reported.
Biopsy↗
High acid secretion may protect the gastric mucosa from injury caused by ammonia produced by Helicobacter pylori in duodenal ulcer patients.
The aim of the present study was to investigate the mechanism by which gastric atrophy does not tend to occur in patients with duodenal ulcer despite frequent Helicobacter pylori infection. This investigation was performed in 60 patients with duodenal ulcer and 63 age-matched gastritis patients. Endoscopic findings in the antrum and corpus were classified as normal, atrophic and superficial changes. Biopsy specimens were taken from the antrum and corpus. Ninety per cent of patients with duodenal ulcer and 63.5% of patients with gastritis had H. pylori infection (P < 0.01). The incidence of normal findings in duodenal patients was 30% in antral regions and 50% in the corpus (P < 0.05). Atrophic change was observed in 21.7% of patients in the antrum and 3.3% of patients in the corpus (P < 0.01). The grade of inflammation in duodenal ulcer specimens was significantly higher in the antrum than in the corpus (P < 0.01). H. pylori density was significantly higher in the antrum than in the corpus in ulcer patients (P < 0.01). No significant difference in endoscopic findings, H. pylori density or the grade of inflammation was found between the antrum and corpus in patients with gastritis. The mean intragastric ammonia concentration was 10.3 mg/dL in duodenal ulcer patients and 6.2 mg/dL in gastritis patients (P < 0.01). The mean pH was 3.5 and 4.6 in ulcer and gastritis specimens, respectively (P < 0.01). Our data suggest that gastric mucosa injury is less frequently associated with duodenal ulcers than with gastritis due to the low H. pylori density in the corpus and to the higher acid output that neutralizes the ammonia produced by H. pylori.
Adult↗
Sequence analyses of human parainfluenza virus type 4A and type 4B fusion proteins.
cDNAs encoding human parainfluenza virus type 4A and type 4B (hPIV-4A and -4B) fusion (F) proteins were cloned and sequenced. The predicted amino acid sequences of the F proteins had similar characteristic traits to those reported for the F proteins of other paramyxoviruses. They were more closely related to the F proteins of simian virus 5 (SV5), mumps virus (MuV), hPIV-2 and Newcastle disease virus (NDV) than to the F proteins of hPIV-1, hPIV-3, Sendai virus (SV) and measles virus (MV). In addition, hPIV-4A, hPIV-4B, SV5 and MuV shared a common feature of genomic organization: there was a small ORF between the F and haemagglutinin-neuraminidase (HN)-coding sequences, implying a common ancestry.
Amino Acid Sequence↗
Fusion properties of cells constitutively expressing human parainfluenza virus type 4A haemagglutinin-neuraminidase and fusion glycoproteins.
We established HeLa cell lines that constitutively expressed the fusion (F) and/or haemagglutinin-neuraminidase (HN) glycoproteins of human parainfluenza virus type 4A (PIV-4A) and used them to analyse the roles of these glycoproteins in virus-induced cell fusion. No syncytium formation occurred, even in HeLa cells expressing both the F and HN proteins (HeLa-4aF+HN cells). Also no syncytium was found in a mixed culture of cells expressing the F protein (HeLa-4aF) and the HN protein (HeLa-4aHN). Syncytia were observed in HeLa-4aF cells transfected with the HN gene, but no syncytium formation was found in HeLa-4aHN cells transfected with the F gene. Co-cultivation of HeLa-4aF+HN cells with HeLa-4aF cells generated large polykaryocytes, whereas co-cultivation with HeLa-4aHN cells induced no cell fusion. Infection of HeLa-4aF cells with PIV-4A generated large syncytia and degenerated nuclei, whereas little or no polykaryocytes were found in HeLa-4aHN cells infected with PIV-4A. From the above findings, the following conclusions were drawn: (i) the expression of both the F and HN proteins in the same cell is necessary for cell fusion; (ii) the expression of the F protein alone enhances susceptibility to cell fusion; (iii) the constitutive expression of the HN protein promotes resistance to paramyxovirus-induced cell fusion.
Cell Fusion↗