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Biomedical subjects

H Sekine

Publications and source records attributed to H Sekine.

At least 37 records · Page 2Linked to original sources
PubMed2000

Changes in gastric acid secretion assayed by endoscopic gastrin test before and after Helicobacter pylori eradication.

BACKGROUND: It remains controversial whether or not Helicobacter pylori infection causes altered gastric acid secretion. A novel test for evaluating gastric acid secretion (endoscopic gastrin test; EGT) has recently been developed. AIM: To investigate by EGT the effects of H pylori eradication on the state of gastric acid secretion in patients with peptic ulcer. METHODS: Twenty six patients with duodenal ulcer and 33 with gastric ulcer, for all of whom H pylori infection had been documented, were studied by EGT, histological examination of gastric mucosa, and measurement of plasma gastrin levels before and one and seven months after H pylori eradication. RESULTS: In patients with duodenal ulcer, the mean EGT value before H pylori eradication was higher than that in H pylori negative controls, but it had decreased significantly seven months after the treatment. In contrast, the mean EGT value of patients with gastric ulcer before H pylori eradication was lower than that in H pylori negative controls, but it had increased one month after the treatment; this was followed by a slight decrease at seven months. In both groups, mean EGT values seven months after the treatment were not significantly different from the mean control value. CONCLUSIONS: The reduced acid secretion in gastric ulcer patients and gastric acid hypersecretion in duodenal ulcer patients were both normalised after the clearance of H pylori.

Adult↗
PubMed2000

HIV infection of megakaryocytic cell lines.

Thrombocytopenia is a common hematologic disorder in HIV infection and occurs in both asymptomatic and AIDS patients. An autoimmune mechanism has been postulated for the platelet destruction associated with some forms of thrombocytopenia. However, recent studies revealed that megakaryocytes are susceptible to HIV infection and suggested the possibility that HIV can directly impair the platelet production from megakaryocytes. This study was designed to characterize the HIV receptor expression in megakaryocytic cells and the responsiveness to HIV infection. Four different megakaryocytic cell lines at different stages of differentiation were established from the peripheral blood of different individuals with hematologic malignancies. CMK and CMY cells (differentiated cell lines) expressed CD4, but CMS and CTS cells (poorly differentiated cell lines) did not. The HIV coreceptor CXCR4 was also expressed in CMY and CMK cells. HIV-1 (HTLV-IIIB) replicated in CMY cells persistently but not in other three cell lines. CMY cells as well as CMK cells were also susceptible to the lytic infection of HIV-2 (LAV2). Pretreatment of the CMY cells with anti-CD4 antibody inhibited the infection by both HIV-1 and HIV-2. Our results indicate that mature megakaryocytic cells express CD4 along with HIV coreceptors and are susceptible to HIV infection.

CD4 Antigens↗
PubMed1999

Opsonic complement component C3 in the solitary ascidian, Halocynthia roretzi.

The recent identification of two mannose-binding lectin-associated serine protease clones from Halocynthia roretzi, an ascidian, suggested the presence of a complement system in urochordates. To elucidate the structure and function of this possibly primitive complement system, we have isolated cDNA clones for ascidian C3 (AsC3) and purified AsC3 protein from body fluid. The deduced primary structure of AsC3 shows overall similarity to mammalian C3, including a typical thioester site with the His residue required for nucleophilic activation of the thioester. AsC3 has a two-subunit chain structure, and the alpha-chain is cleaved at a specific site near to the N terminus upon activation. Ascidian body fluid contains an opsonic activity which enhances phagocytosis of yeast by ascidian blood cells, and Ab against AsC3 inhibits this opsonic activity. These results indicate that the complement system played a pivotal role in innate immunity by enhancing phagocytosis before the emergence of the vertebrates and well ahead of the establishment of adaptive immunity, which is believed to have occurred at about the time of the appearance of cartilaginous fish.

Amino Acid Sequence↗
PubMed1999

A novel amino acid substitution at the receptor-binding site on the hemagglutinin of H3N2 influenza A viruses isolated from 6 cases with acute encephalopathy during the 1997-1998 season in Tokyo.

We analyzed the hemagglutinin (HA) genes of influenza A viruses consisting of 6 strains isolated from cerebrospinal fluids of patients with encephalopathy and 3 isolates from throat washes of patients without central nervous system symptoms during the 1997-1998 season in Tokyo. Aligned 9 amino acid sequences showed 7 common substitutions compared with A/Wuhan/359/95 (vaccine strain used in the season in Japan), which were allocated to three different antigenic sites on the H3 HA molecule. It is noted that a novel substitution at the receptor-binding site (Tyr-137 to Phe) was found exclusively in the isolates from the patients with encephalopathy.

Amino Acid Sequence↗
PubMed1999

Burch bladder neck suspension for cystocele repair: the necessity of combined vaginal procedures for severe cases.

BACKGROUND: Burch operation is an accepted form of bladder neck suspension for small cystoceles. The purpose of the present study was to evaluate the efficacy of Burch repair for severe cystoceles compared with Burch repair along with vaginal procedures. METHODS: A total of 14 patients with severe cystocele (grade III-IV) treated with open Burch operation were evaluated retrospectively. Of these patients, eight were Burch only and the remaining six underwent combined Burch with vaginal repair (anteroposterior vaginal wall plasty and hysterectomy). RESULTS: After a mean follow up of 40 months (range 6-80), cystocele recurred in one patient at 1 month, and rectocele became prominent in three patients, including one who also presented uterine prolapse among the Burch-only group. Conversely, all six patients who underwent the combined operation showed no occurrence of cystocele or rectocele. The proportion of patients not failing treatment was significantly higher in the combined operation group than in the Burch-only group. Intermittent self-catheterization was needed in one patient from the combined operation group for 6 months, but all other patients had restored smooth urination within a few weeks after the operation. CONCLUSIONS: The results suggest that, for severe cystoceles, Burch-only repair is insufficient and combined Burch with vaginal repair should be used to manage various pelvic hypermobility symptoms.

Aged↗
PubMed1999

Helicobacter pylori infection inhibits reflux esophagitis by inducing atrophic gastritis.

OBJECTIVE: Although it is widely accepted that Helicobacter pylori (H. pylori) infection is an important cause of atrophic gastritis, few studies have examined the relationship between H. pylori-induced atrophic gastritis and the occurrence of reflux esophagitis. The present study was aimed to examine the relationship between H. pylori infection, atrophic gastritis, and reflux esophagitis in Japan. METHODS: A total of 175 patients with reflux esophagitis were compared with sex- and age-matched 175 control subjects. Diagnosis of H. pylori infection was made by gastric mucosal biopsy, rapid urease test, and serum IgG antibodies. Severity of atrophic gastritis was assessed by histology and serum pepsinogen I/II ratio. RESULTS: H. pylori infection was found in 59 (33.7%) patients with reflux esophagitis, whereas it was found in 126 (72.0%) control subjects. The grade of atrophic gastritis was significantly lower in the former than in the latter. Among the H. pylori-positive patients, atrophic gastritis was milder in the patients with reflux esophagitis than in the patients without it. CONCLUSIONS: These findings suggest that most cases of reflux esophagitis in Japan occur in the absence of H. pylori infection and atrophic gastritis, and it may also tend to occur in patients with milder gastritis even in the presence of H. pylori infection. Therefore, H. pylori infection may be an inhibitory factor of reflux esophagitis through inducing atrophic gastritis and concomitant hypoacidity.

Adult↗
PubMed1999

Coexpression of mineralocorticoid receptors and 11beta-hydroxysteroid dehydrogenase 2 in human gastric mucosa.

The role of mineralocorticoids in human gastrointestinal tract is well established. In the stomach, aldosterone is thought to regulate electrolyte transport associated with gastric acid secretion. In mineralocorticoid target organs, the action of the glucocorticoid inactivating enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) facilitates aldosterone binding to a nonselective mineralocorticoid receptor (MR) in the face of high levels of circulating glucocorticoids. In the present study, we examined 25 specimens of human stomach for the presence of MR and 11beta-HSD2 using a [3H]aldosterone binding assay, Northern blot analysis, RT-PCR, and immunohistochemistry. Specific [3H]aldosterone binding sites were detected in gastric fundic mucosa, but not in the antrum. In fundic mucosa the Kd was 0.72+/-0.05 nmol/L (mean +/- SE), and Bmax was 6.0+/-1.4 fmol per milligram of protein. Northern blot analysis demonstrated a faint band for MR mRNA at 6.0 kb, although message for 11beta-HSD2 was undetectable. However, RT-PCR demonstrated specific PCR products for both MR and 11beta-HSD2. Immunohistochemistry demonstrated the colocalization of MR and 11beta-HSD2 only in parietal cells. MR-positive cells were further characterized by electron microscopy, confirming the identity of parietal cells. This study shows that parietal cells contain both MR and 11beta-HSD2, suggesting that the human stomach is a novel target organ for mineralocorticoids. Aldosterone may, therefore, regulate biological functions of parietal cells including gastric acid secretion.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1999

Cloning and expression of a cDNA encoding the laccase from Schizophyllum commune.

We cloned and analyzed the nucleotide sequence of a cDNA that encodes polyphenol oxidase (laccase) from the white-rot basidiomycete Schizophyllum commune. The nucleotide sequence of the full-length cDNA contained a 1554-base open reading frame that encoded a polypeptide of 518 amino acid residues, including a putative signal peptide of 16 residues. It contained four highly similar regions that are conserved in the deduced amino acid sequences of other laccases, including the region thought to be involved in copper binding. Aspergillus sojae strain 1860 (which has low protease levels) was transformed with the plasmid lacAL/pTPT, which contained the laccase gene under the control of the tannase promoter from Aspergillus oryzae. Laccase was secreted into the medium when transformants A1 and A2 were cultured in tannic acid-containing medium.

Amino Acid Sequence↗
PubMed1999

[Recurrence rate of H. pylori after successful eradication and second eradication therapy after initial failure of treatment].

Three hundred thirty-three patient (116 gastric ulcer, 119 duodenal ulcer, 98 gastritis) who were successfully eradicated were enrolled in the study of H. pylori recurrence rate. H. pylori status was determined by histology, rapid urease test, 13C-urea breath test. The mean of the follow-up period was 13.3 months (2-56 months), and 15 patients showed negative to positive conversion of H. pylori. The recurrence rate was 4.4% for one year and 8.3% for two years using Kaplan-Meier analysis. Second eradication therapy after initial failure is another concern. Nineteen patients were assigned to receive an 1-week new triple therapy (clarithromycin, metronidazole and PPI), in whom a 2-week course of dual therapy (amoxicillin plus PPI) failed (group1). Another 15 patients in whom the 1-week new triple therapy failed were switched to the 2-week course of dual therapy plus ecabet sodium (group2). H. pylori was eradicated in 84.2% (16/19) of patients in group1 and 86.7% (13/15) in group2.

Amoxicillin↗
PubMed1999

[Increased acid secretion after Helicobacter pylori eradication is the important risk factor of acute duodenitis and reflux esophagitis].

The aims of this study were to investigate whether the changes in gastric acid secretion after H. pylori eradication might influence the development of acute duodenitis (AD) and reflux esophagitis (RE). Stimulated acid output was assessed by EGT (mEq/10 min), which is the new endoscopic method of gastric secretory testing described previously. Changes in the EGT values before and after eradication were divided into 4 groups; decreased group, no change group, increased group, markedly increased group. Results estimated by EGT demonstrated that AD and RE development after eradication significantly correlated with the increase of acid secretion. In conclusion, the increase of acid secretion was thought to be one of the most important risk factors of both AD and RE developed after H. pylori eradication.

Acute Disease↗
PubMed1999

[The expression of chemokines and the dynamics of inflammatory cell infiltration before and after H. pylori eradication].

We attempted to evaluate the relationship between the expression of IL-8 and RANTES and the dynamics of their target cells in human gastric mucosa of H. pylori associated gastritis, including their changes after H. pylori eradication. We performed the measurement of the mucosal level of IL-8 and RANTES protein by ELISA and immunohistochemistry. The neutrophil infiltration into the gastric mucosa was identified by the histological examination based on the Updated Sydney system and the measurement of MPO activity. The memory T lymphocyte and eosinophil were indicated by immunohistochemistry of CD45RO that is one of surface markers indicating memory T lymphocytes and MBP that is contained in the granules of eosinophils. H. pylori positive gastric mucosa demonstrated a remarkable increase in neutrophils. CD45RO positive cells and eosinophils, compared to H. pylori negative gastric mucosa. Gastric mucosal level of IL-8 and RANTES protein and MPO activity was significantly higher in H. pylori positive cases than that in H. pylori negative controls after H. pylori eradication, both of the level of IL-8 protein and MPO activity reduced at the same levels as negative controls. However, RANTES expression, CD45RO positive T lymphocytes and eosinophils remained in H. pylori eradicated gastric mucosa at the significantly high level, compared with H. pylori negative cases. Therefore, it seems possible that IL-8 might enhance the inflammation by facilitating the neutrophil infiltration into H. pylori infected gastric mucosa and that RANTES might play an important role in the specific immune response against H. pylori and the maintenance of the immune memory after H. pylori eradication.

Adult↗
PubMed1999

[Usefulness of visualized highly sensitive new chemical dosimeter: application to blood irradiation].

In the prophylaxis of post-transfusion GVHD, it is recommended to irradiate blood components with an absorbed dose ranging from 15 Gy to 50 Gy. We applied a new chemical dosimeter to measure absorbed dose for blood irradiation. This system is composed of diphenyliodoniumchloride (DICI) as an oxidizer and crystal violet lactone as a pH indicator. Protons are released from DICI after irradiation. The maximum absorption wavelength of this indicator is 610 nm, and absorbance is linearly related with a given dose from 1 to 50 Gy. Coloration is stable for at least 2 weeks when stored in the dark at 4 degrees C. This system may be used as a chemical dosimeter for blood irradiation.

Blood↗
PubMed1998

Two lineages of mannose-binding lectin-associated serine protease (MASP) in vertebrates.

Mannose-binding lectin-associated serine protease (MASP) is a newly identified member of the serine protease superfamily. MASP is involved in host defense against pathogens through a novel system of complement activation, designated the lectin pathway. To elucidate the origin of the lectin pathway and the molecular evolution of MASP, we cloned six MASP cDNAs from five vertebrate species going from mammal to cyclostome. An alignment of the amino acid sequences deduced from the cDNAs revealed the presence of two different lineages of the MASP gene. This classification was supported by the precise correlation with two types of exon organization for the protease domain. One of the two lineages is unique in that a single exon encodes the protease domain, unlike most other serine proteases. All members of this group, termed the AGY type, have an AGY codon at the active site serine. A phylogenetic tree suggests that the AGY type diverged from another lineage, termed the TCN type, before the emergence of primitive vertebrates. Furthermore, the presence of MASP or MASP-like sequences in most vertebrate species suggests that the lectin pathway functions extensively in vertebrates and that its origin is traced back to the invertebrate stage.

Amino Acid Sequence↗
PubMed1998

Analysis of peripheral blood mononuclear cell stimulated with pyruvate dehydrogenase complex, T-cell receptors from patients with primary biliary cirrhosis.

Progressive destruction of the intrahepatic bile ducts in patients with primary biliary cirrhosis (PBC) is thought to be mediated by cytotoxic T cells which recognize certain epitopes, such as the pyruvate dehydrogenase complex (PDC). To clarify the T-cell repertoire in PBC, we analyzed T-cell receptor (TCR) Vbeta-chain messages expressed in peripheral blood mononuclear cells (PBMCs) stimulated with PDC and in liver biopsy specimens. PBMCs from 12 PBC patients and 6 healthy controls were examined. The TCR Vbeta repertoires of unstimulated PBMCs and PBMCs stimulated with PDC purified from bovine heart were analyzed, using the reverse transcriptase-polymerase chain reaction (RT-PCR) and single-strand conformation polymorphism (SSCP). Liver biopsy specimens from 5 PBC patients were also analyzed. In the PBC patients, several different T-cell clones, some of which showed the same mobility, were evident in both the PDC-stimulated and unstimulated PBMCs, as demonstrated by SSCP analysis. In addition, TCR clonality of infiltrating lymphocytes in the liver was also observed in PBC patients, showing common clonal T-cell accumulation with that seen in PBMCs stimulated with PDC. These data indicate that common clonal T-cell accumulation specific for PDC may be present in both peripheral PBMCs and the liver of patients with PBC.

Case-Control Studies↗
PubMed1998

Primary localized amyloidosis of the ureter.

Localized amyloidosis of the ureter is a relatively rare condition. We report a case of primary localized ureteral amyloidosis. A 66-year-old man was referred to our hospital complaining of right flank pain and gross hematuria. From the right hydronephrosis and irregular margin of the right lower ureter seen on the anterograde pyelography, we could not rule out a right ureteral malignancy. Total nephroureterectomy was performed and histologic examination showed ureteral amyloidosis. Amyloid was classified immunohistochemically as Alambda type. After all examinations for secondary or systemic amyloidosis were negative, primary localized amyloidosis of the ureter was confirmed.

Aged↗
PubMed1998

A new endoscopic method of gastric acid secretory testing.

OBJECTIVE: To date, the effect of Helicobacter pylori on acid secretion remains controversial. To evaluate changes in the gastric acid secretory response before and after H. pylori eradication in a large number of patients, we devised a new endoscopic method of gastric acid secretory testing, the endoscopic gastrin test (EGT). METHODS: In EGT, endoscopy was begun 15 min after intramuscular injection of 4 microg/kg tetragastrin. Gastric fluid secreted between 20 and 30 min after gastrin injection was aspirated and collected during endoscopic examination. The amount of acid in the sample collected over this 10-min period was estimated by titration and expressed in H+ mEq/10 min. Fifteen subjects underwent a conventional secretory test using a nasogastric tube (conventional method) and EGT on different days to assess the correlation between results obtained with the two methods. In 10 of these subjects, EGT was repeated under the same conditions to assess its reproducibility. RESULTS: EGT values correlated very well with peak acid output determined by the conventional method (n = 15, r = 0.92) and had high reproducibility (n = 10, CV = 5.6). We noted that EGT takes just a little longer to perform than a routine endoscopic examination, and the influence of an endoscope in the stomach on acid secretion was not present. CONCLUSION: The EGT should be very useful as a rapid, simple substitute for conventional secretory testing when repeated gastric secretory tests are required, especially in investigating the effect of H. pylori on acid secretion in a larger population.

Adult↗
PubMed1998

[Increased IL-2 and sIL-2R in sera of infants with HTLV-I infection from mother].

In our laboratory, children born to women are known to be infected with Human T-cell Leukemia Virus type-1 (HTLV-I) have been followed using, detect of gene by PCR and antibody by Western Blot Assay (WB) and Immunofluorescence Assay (IFA) test from 1990 through 1996. Four children out of 123 delivery cases have been confirmed to be infected with HTLV-I. We analyzed the correlation between the concentration of cytokines (IL-2, sIL-2R, IFN-gamma) and HTLV-I infection. IL-2 and sIL-2R in sera increased after HTLV-I infection. There was no correlation between the concentration of IFN-gamma and HTLV-I infection. These result suggested that detection of IL-2 and sIL-2R might be the marker of HTLV-I infection.

Biomarkers↗