Search PubMed⌕ Search

Biomedical subjects

M Hirai

Publications and source records attributed to M Hirai.

At least 181 records · Page 10Linked to original sources
PubMed1997

Extracellular production of an intact and biologically active human growth hormone by the Bacillus brevis system.

The characteristic features of the Bacillus brevis system are very high productivity of heterologous proteins and very low extracellular protease activity. However, degradation of some heterologous proteins, especially mammalian proteins, can be observed and resulted in a lowering of protein productivity. By using a mutant expressing low levels of proteases and the addition of EDTA to the medium, intact human growth hormone (hGH) was successfully produced with the B. brevis system. Signal peptide modification with higher basicity in the amino terminal region and higher hydrophobicity in the middle region brought about a twelve-fold increase in hGH production. The hGH yield was further elevated to 240 mg L-1 by optimization of culture conditions. Thus, biologically active and mature hGH can be efficiently produced directly in the medium with the B. brevis system.

Amino Acid Sequence↗
PubMed1997

Susceptibility of Helicobacter pylori isolates to metronidazole, clarithromycin and amoxycillin in vitro and in clinical treatment in Japan.

BACKGROUND: Primary and acquired resistance to antibiotics is an important factor in determining the reason for treatment failure in Helicobacter pylori infection. We examined the relationship between the susceptibility of H. pylori isolates and the efficacy of chemotherapy. METHODS: The minimal inhibitory concentrations (MICs) of metronidazole (MNZ), clarithromycin (CLAR) and amoxycillin (AMOX) of 320 H. pylori pre-treatment isolates were determined by the agar dilution method. In 290 patients with peptic ulcers. H. pylori infection was treated by dual or triple combination therapies for 2 weeks: one proton pump inhibitor (30 mg/day lansoprazole or 20 mg/day omeprazole) and one or two antibiotics (500 mg AMOX, 200 mg CLAR or 250 mg MNZ twice a day). MICs were also determined after the treatment failure. RESULTS: Among the drugs tested, for MNZ and CLAR, 8.1% and 9.1% of the isolates, respectively, were resistant, while no isolate was resistant to AMOX. After unsuccessful treatment using MNZ and CLAR, 66.7% and 70.61% of the isolates changed from sensitive to resistant, respectively. All isolates were sensitive to AMOX after treatment failure. CONCLUSIONS: The failure of the H. pylori treatment results in the induction of resistance to CLAR and/or MNZ. Regimens with a high cure rate should be used in order to prevent the generation of acquired resistance to antibiotics.

Adolescent↗
PubMed1997

A nitric oxide-releasing reagent, S-nitroso-N-acetylpenicillamine, enhances the expression of superoxide dismutases mRNA in the murine macrophage cell line RAW264-7.

Murine interferon-gamma (IFN-gamma) stimulates the murine macrophage tumour cell line RAW264-7 to produce nitric oxide (NO). IFN-gamma induces expression of inducible NO synthase (iNOS), manganese superoxide dismutase (Mn-SOD) and copper zinc SOD (CuZn-SOD) in these cells. To investigate the mechanism of induction of SOD expression, we added S-nitroso-N-acetyl penicillamine (SNAP) to RAW264-7 cells. SNAP enhanced the expression of Mn-SOD and CuZn-SOD. These results suggest that when producing NO, RAW264-7 cells express SOD that might protect them from NO toxicity.

Animals↗
PubMed1997

Uterine sarcoma: can it be differentiated from uterine leiomyoma with Doppler ultrasonography? A preliminary report.

Our objective was to evaluate whether intratumoral-blood flow analysis could differentiate uterine sarcoma from uterine leiomyoma. Color and pulsed Doppler findings obtained from 41 patients with histologically proven uterine leiomyoma and five with uterine sarcoma (four leiomyosarcoma, one mixed mesodermal tumor) were retrospectively assessed. Intratumoral blood flow velocity waveforms were recorded, and the resistance index (RI) and peak systolic velocity (PSV) were calculated. There was no significant difference between the RI (median 0.647; range 0.422-0.896) in the uterine leiomyomas and the RI (median 0.663; range 0.330-0.774) in the uterine sarcomas. The PSV (median 61.6 cm/s; range 40.0-124.0 cm/s) in the uterine sarcomas was significantly higher (median 21.6 cm/s, range 6.3-48.6 cm/s) than that in the uterine leiomyomas (p < 0.05). When a cut-off value for the PSV of 41.0 cm/s (mean PSV of the uterine leiomyomas plus 2 standard deviations) was considered, the detection rate for uterine sarcoma was 80.0%, and the false-positive rate was 2.4%. These results suggest that the PSV within the tumor detected by color and pulsed Doppler ultrasonography could be useful for the preoperative differential diagnosis of uterine sarcoma.

Adult↗
PubMed1997

Hypoxaemia in patients with hyperventilation syndrome.

We assessed 12 patients with hyperventilation syndrome (HVS) who had experienced hypoxaemia (PaO2 < 60 Torr or SaO2 < 90%) despite the lack of any other organic disease and variability in their blood gas data. Hypoxic and hypercapnic ventilatory responses were measured in nine. Eight of the 12 patients had been referred from other hospitals to our institution for hypoxaemia of unknown origin. Mean PaO2 (n = 12) at rest (non-attack stage) was 87.3 +/- 7.5 Torr (mean +/- SD). Their (n = 9) hypoxic (-0.53 +/- 0.32 l/min/%; range 0.12-0.99) and hypercapnic (2.01 +/- 0.76 l/min/Torr; range 0.69-3.17) ventilatory responses were both within the normal range in our laboratory. The patients with HVS had variable blood gas data, and some of them also exhibited hypercapnia (PaCO2 > 45 Torr). Clinicians who treat patients with HVS should be aware of the possibility of hypoxaemia, even when ventilatory responses are normal. Physicians should also consider HVS as a diagnosis when treating patients with hypoxaemia of unknown origin.

Adult↗
PubMed1997

Analysis and typing of the vacA gene from cagA-positive strains of Helicobacter pylori isolated in Japan.

Approximately 50% of Helicobacter pylori strains produce a cytotoxin that is encoded by vacA and that induces vacuolation of eukaryotic cells. Mosaicism in vacA alleles was reported, and there are three different families of vacA signal sequences (s1a, s1b, and s2) and two different families of middle-region alleles (m1 and m2). In addition, the vacA genotype of a strain is associated with its cytotoxin phenotype and its capacity to induce peptic ulceration. To clarify the strain diversity of H. pylori in Japan, 87 Japanese clinical isolates of H. pylori (40 from patients with chronic atrophic gastritis, 25 from patients with duodenal ulcer, 16 from patients with gastric ulcer, 3 from patients with both duodenal and gastric ulcers, and 3 from patients with intestinal type gastric cancer) were characterized by vacA typing by PCR and DNA sequencing. Eighty-four of the 87 isolates were s1a/m1, one was s1b/m1, and two could not be typed. Moreover, all isolates in this study were cagA positive. There were no distinct differences between the cytotoxin-producing strains and cytotoxin-nonproducing strains within the 0.73-kb middle region. Japanese strains were highly homologous, with more than 96% identity in this region, in which maximum divergence has been reported. In addition, there were no associations between the specific vacA types and the level of in vitro cytotoxin activity or the clinical consequences. These results indicate that the cagA-positive, s1a/m1-type strains are common in Japan, regardless of the vacA phenotype or clinical outcome.

Antigens, Bacterial↗
PubMed1997

Effects of Helicobacter pylori eradication therapy on hyperammonaemia in patients with liver cirrhosis.

BACKGROUND AND AIMS: Helicobacter pylori has strong urease activity. Ammonia produced by H pylori in the stomach can be a source of systemic ammonia in patients with hepatic dysfunction. The effect of the eradication of H pylori on hyperammonaemia was examined in patients with liver cirrhosis. SUBJECTS AND METHODS: Ammonia concentrations in blood and gastric juice were analysed in 50 patients with liver cirrhosis and hyperammonaemia. All patients were first treated with a low protein diet, kanamycin, lactulose, and branched chain enriched amino acid solution. Hyperammonaemia remained in 18 patients. These 18 patients were divided into three groups according to the status of H pylori infection; those with a diffuse distribution of H pylori in the stomach (group I), those with a regional distribution (group II), and those without H pylori (group III). These patients were given 30 mg iansoprazole, 1000 mg amoxicillin, and 400 mg clarithromycin or 500 mg metronidazole for two weeks to eradicate H pylori. RESULTS: In group I ammonia concentrations in blood and gastric juice were significantly reduced after H pylori eradication. The blood ammonia concentration at 12 weeks after the eradication was still significantly lower than that before eradication. In groups II and III the ammonia concentrations in blood and gastric juice were not significantly reduced after eradication therapy. CONCLUSIONS: The diffuse distribution of H-pylori in the stomach contributes partly to hyperammonaemia in patients with liver cirrhosis, and the eradication of H pylori is effective in patients with hyperammonaemia with diffuse H pylori infection in the stomach.

Adult↗
PubMed1997

Production of recombinant Der fI with the native IgE-binding activity using a baculovirus expression system.

Der fI is a cysteine protease contained in feces of mites and is one of major mite allergens. Recombinant Der fI (reDer fI) that is produced using a baculovirus expression system contains pro-sequences of different lengths. Most of these can be removed by acid treatment. However, IgE-binding activity of acid-treated reDer fI is lower than that of native Der fI at high protein concentrations, and N-terminal amino acids of acid-treated reDer fI are not uniform. Now, a method for processing of the pro-sequence has been developed by producing reDer fI E(-1)K with baculovirus expression system in which the carboxy terminal amino acid of the pro-sequence (glutamate) was replaced by lysine using site directed mutagenesis. No difference in the amount of production was observed upon introducing the mutation into the pro-sequence. Addition of lysylendopeptidase into the culture medium led to processing of the pro-sequence of reDer fI E(-1)K and proceeded the degradation of the other proteins in the medium. Lysylendopeptidase-treated reDer fI E(-1)K was easily purified with an anion exchange column, resulting in 20% increase of the yield. Lysylendopeptidase-treated reDer fI E(-1)K obtained through these processes was compared with the native Der fI. Although some differences were found in protease activity and reactivity with lectins, their N-terminal amino acid and the IgE-binding activity were the same as those of the native one, indicating its usefulness for diagnostic purpose.

Animals↗
PubMed1997

[Microalbumin and N-acetyl-beta-D-glucosaminidase in random spot urine samples as predictors of diabetic nephropathy in the elderly non-insulin dependent diabetic patients].

To determine whether urinary albumin to creatinine ratio (Albumin index) and urinary N-acetyl-beta-D-glucosaminidase (NAG) to creatinine ratio (NAG index) in random spot urine samples can be sued to predict the early stage of diabetic nephropathy in the elderly non-insulin dependent diabetic patients, we measured these concentrations in 150 non-diabetics, 61 diabetics without retinopathy and 56 diabetics with retinopathy. All patients with Albustix-positive urine were excluded. Subjects divided into two groups according to whether they were < 60 years (adult group) or > or = 60 years old (old group). Multiple regression analysis was used to investigate the relationship between NAG index or Albumin index (dependent variable) and independent variables (age, systolic blood pressure, duration of diabetes. HbA1c) in diabetic patients. Diabetic patients with retinopathy showed the highest mean Albumin index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Diabetic patients with retinopathy showed the highest mean NAG index, followed by diabetic patients without retinopathy and then non-diabetic patients both in adult group and in old group (p < 0.001, p < 0.001, respectively). Albumin index positively correlated with systolic blood pressure, duration of diabetes and HbA1c (r = 0.18, r = 0.35, r = 0.18, respectively). NAG index positively correlated with age, duration of diabetes and HbA1c (r = 0.18, r = 0.25, r = 0.29, respectively). These results suggest that both NAG index and Albumin index in random spot urine samples may serve as early functional indicators of diabetic nephropathy in elderly diabetics.

Acetylglucosaminidase↗
PubMed1997

Changes in the arterial PCO2 during a single night's sleep in patients with obstructive sleep apnea.

To investigate the relationship between hypercapnia during sleep and its influence on the PaCO2 during the morning after sleep in patients with obstructive sleep apnea syndrome (OSAS), the transcutaneous PCO2 (PtcCO2) was measured throughout the night, and the arterial blood gases (ABG) were also measured while awake before and after polysomnography in 30 OSAS patients with (n=13, hypercapnic group: HC) and without (n=17, normocapnic group: NC) hypercapnia. Significant differences were observed in the body mass index (p=0.03), the difference between the highest PtcCO2 during sleep and the PtcCO2 during awake before sleep (D-PtcCO2), (HC: 11.l+/-1.7 mmHg; NC: 6.3+/-0.5 mmHg; p=0.0057) and the lowest SaO2 during sleep (p=0.0007). In the HC, the PaCO2 on the morning after sleep (50.0+/-0.14 mmHg) was significantly increased (p=0.0029) compared with the PaCO2 on the night before sleep (47.4+/-1.1 mmHg). In the NC, this phenomenon was not observed. Severe hypercapnia (high D-PtcCO2) during a single night's sleep has a significant effect on the waking PaCO2 immediately following sleep in the HC.

Body Mass Index↗
PubMed1997

[Successful treatment of heavy-chain disease with etoposide].

A 79-year-old man with marked hepatosplenomegaly and lymphadenopathy was admitted to the hospital. Analysis of serum protein resulted in the diagnosis of gamma-chain disease (total protein 6.2 g/dl, M-protein positive, IgG 4150 mg/dl, IgG-Fc fragment positive). Specimens obtained by lymph node biopsies showed infiltration of plasmacytoid cells, which were stained with anti-IgG but not with anti-kappa or anti-lambda antibodies. The patient was given combination chemotherapy, but without effect. Then a regimen of long-term administration of low-dose etoposide was begun, and resulted in remission of the lymphadenopathy, hepatosplenomegaly, and abnormal IgG.

Administration, Oral↗
PubMed1997

[Successful pulmonary thromboendarterectomy in a patient with chronic pulmonary thromboembolism].

A 63-year-old patient had been diagnosed with angina pectoris for 5 months and came to us complaining of progressive exertional dyspnea. Echo cardiography showed remarkable pulmonary hypertension and we were prompted to do cardiac catheterization. The catheterization showed the pressure of the main pulmonary artery (PA) as 84/14 (36) mmHg and PA angiography showed a massive embolus in the right main PA. Chest computed tomography and lung perfusion scintigraphy were also compatible with pulmonary embolism. The patient had been treated with anticoagulant for 1 month, but he was not doing well. We decided to remove the embolus surgically. In a median sternotomy, a cardiopulmonary bypass was established with ascending aortic and two caval cannulae. During cooling, the right PA was mobilized within the pericardial reflection. An incision was made in the right PA. An organized thrombus was located at the central PA and extended to the distal segmental PA. Thromboendarterectomy was carried out carefully. To obtain a better operative view, circulatory arrest was introduced intermittently. The left PA was opened and the organized thrombus, located at the bifurcation between the upper and lower branch, was removed. Post-operative PA angiography showed remaining thrombus in the right lower PA, but the pressure of the main PA fell to 27/12 (18) mmHg. Pulmonary thromboendarterectomy by median sternotomy with the aid of deep hypothermia and circulatory arrest was useful to remove the thrombus in the bilateral PA, and to obtain good hemodynamic and symptomatic results.

Endarterectomy↗
PubMed1997

[A case report on prosthetic valve dysfunction of the Carpentier-Edwards pericardial bioprosthesis in the tricuspid position associated with remarkable hypoproteinemia].

A 66-year-old woman underwent a second tricuspid valve replacement because of a malfunction of the Carpentier-Edwards pericardial bioprosthesis (CEP) in the tricuspid position 3.5 years after her first mitral and tricuspid valve replacement. The major symptom was lower leg edema and a serum albumin level ranging between 1.5 g/dl and 2.0 g/dl. The remarkable hypoproteinemia might have resulted from impaired albumin synthesis due to liver dysfunction, hemodilution, protein losing gastroenteropathy, and changes in albumin distribution due to edema. Although the explanted CEP showed neither dehiscence nor calcification of the leaflet, fibrous pannus mainly on the ventricular side restricted the mobility of the corresponding leaflet. Patients receiving a CEP in the tricuspid position should receive careful follow-up.

Aged↗
PubMed1996

Inactivation of p16/CDKN2 and p15/MTS2 genes in different histological types and clinical stages of primary ovarian tumors.

To define the involvement of p16/CDKN2 and p15/MTS2 inactivation in ovarian tumorigenesis and the association of these inactivation events with histological types and clinical stages of ovarian tumors, we analyzed homozygous deletion and somatic mutation of p16/CDKN2 and p15/MTS2 genes, as well as hypermethylation of the 5'-CpG island of the p16/CDKN2 gene, in 49 primary ovarian tumors and 6 ovarian carcinoma cell lines. We found homozygous deletions of p16/CDKN2 and p15/MTS2 in 6 (12%) and 5 (10%) primary tumors, respectively. Somatic mutation of p16/CDKN2 was found in only 1 primary tumor, but mutation of p15/MTS2 was not detected in any sample. None of the 28 primary tumors or 6 cell lines was hypermethylated at the 5'-CpG island of p16/CDKN2. The incidence of inactivation of p16/CDKN2 in primary tumors was significantly higher in the advanced stages (7 of 29) than in the early stages (0 of 14). Seven of 9 alterations in p16/CDKN2 and p15/MTS2 were observed in serous (3 of 12), endometrioid (3 of 9) and clear-cell (1 of 4) carcinomas. However, only normal sequences of these genes were detected in mucinous carcinomas. Loss of heterozygosity (LOH) at the IFNA locus was detected in 1 of 19 (5%) tumors, but no change at the D9S171 locus was observed in 17 tumors. These results suggest that: (i) homozygous deletion is the main mechanism of inactivation of p16/CDKN2 and p15/MTS2 in ovarian tumorigenesis; (ii) inactivation of p16/CDKN2 and p15/MTS2 may be the histological type-specific events involved in ovarian tumorigenesis; and (iii) inactivation of p16/CDKN2 is potentially involved in the progression of ovarian tumors in advanced stages.

Carcinoma↗
PubMed1996

cDNA cloning, expression and characterization of nitric-oxide synthase from the salivary glands of the blood-sucking insect Rhodnius prolixus.

Rhodnius prolixus, a blood-sucking bug, is a unique insect that is known to produce nitric oxide (NO) in the salivary glands to use as a vasodilator for blood sucking. We report here the cloning of the NO synthase (NOS) cDNA from these salivary glands and its expression in a baculovirus system. This cDNA encodes a protein of 1174 amino acids with a calculated molecular mass of 132,331 Da. The primary structures of mammalian NOS, including the putative cofactor-recognition sites for heme, tetrahydrobiopterin (BH4), calmodulin. FMN, FAD and NADPH are all conserved in salivary-gland NOS. Recombinant salivary-gland NOS differed from nerve NOS and endothelial NOS in that it lacked a large N-terminal domain and an N-terminal myristylation sequence, respectively. Salivary-gland NOS produced in a baculovirus system showed NOS activity and demonstrated that salivary-gland NOS was soluble and was Ca2+ and calmodulin dependent, similarly to mammalian constitutive NOS isoforms. Recombinant salivary-gland NOS was purified to near homogeneity and migrated at 130 kDa on SDS/PAGE.

Amino Acid Sequence↗
PubMed1996

Cloning, expression and chromosomal localization of Wnt-13, a novel member of the Wnt gene family.

The Wnt genes, encoding structurally-related secreted glycoproteins, are implicated in mammary carcinogenesis induced by mouse mammary tumor virus. In search of the Wnt gene(s) expressed in human gastric cancer, a WTGC1 cDNA fragment sharing 66.9% amino-acid homology with human and mouse Wnt-2 was isolated by degenerate polymerase chain reaction. The human gene corresponding to WTGC1 was designated as Wnt-13 and overlapping Wnt-13 cDNAs were cloned. Nucleotide sequence analysis indicated that the Wnt-13 gene encodes the protein of 372 amino acids, including a signal peptide, two potential N-glycosylation sites and 24 cystein residues highly conserved among members of the Wnt gene family. The Wnt-13 mRNA of 2.5 kb in size was detected in heart, brain, placenta, lung, prostate, testis, ovary, small intestine and colon of adult human and also in brain, lung and kidney of fetal human. Among various cancer cell lines, the Wnt-13 mRNA was detected in HeLa (cervical cancer), MKN28 and MKN74 (gastric cancer). The Wnt-13 gene has been mapped to human chromosome 1p13. These results suggest that the Wnt-13 gene may be involved in normal human development or differentiation as well as in human carcinogenesis.

Adult↗
PubMed1996

Expression of cathepsin E in pancreas: a possible tumor marker for pancreas, a preliminary report.

Ductal cancers of the pancreas frequently express markers of gastrointestinal epithelial cells. Cathepsin E (CTSE) is a non-secretory, intracellular, but non-lysosomal proteinase found in the highest concentration in the superficial epithelial cells of the stomach. The aims of our study were to examine the expression of CTSE in the pancreas, to establish an assay system of CTSE and to evaluate the diagnostic usefulness of CTSE in the pancreatic juice. Eleven patients with pancreatic ductal adenocarcinoma, 10 with mucin-producing adenoma, 3 with intraductal papillary hyperplasia and 43 with chronic pancreatitis were examined. Surgically resected pancreatic tissues were subjected to immunohistochemistry for CTSE. Pancreatic juice was collected from the patients and subjected to sandwich ELISA and Western analysis for detecting CTSE. Positive staining for CTSE was observed in pancreatic ductal adenocarcinoma by immunohistochemistry. CTSE was also expressed in mucin-producing adenoma, intraductal papillary hyperplasia and mucinous hyperplasia. CTSE in the pancreatic juice was present in 8 of 11 patients with pancreatic ductal adenocarcinoma, 5 of 10 patients with mucin-producing tumor, 1 of 3 patients with intraductal papillary hyperplasia and 4 of 43 patients with chronic pancreatitis. The detection frequency of CTSE in the pancreatic juice was significantly higher in the patients with pancreatic ductal adenocarcinoma than in the patients with chronic pancreatitis. Our findings suggest that the expression of CTSE is associated with the pathogenesis of pancreatic ductal adenocarcinoma, that CTSE in the pancreatic juice seems to be a useful marker for a definitive diagnosis and that CTSE may be expressed at a relatively early stage of multistep carcinogenesis in pancreatic lesions.

Adult↗