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Biomedical subjects

S Ito

Publications and source records attributed to S Ito.

At least 397 records · Page 22Linked to original sources
PubMed2000

Deduced amino acid sequence and possible catalytic residues of a thermostable, alkaline cellulase from an Alkaliphilic bacillus strain.

Alkaliphilic Bacillus sp. strain KSM-S237 (a relative of Bacillus pseudofirmus) produces a thermostable, alkaline endo-1,4-beta-glucanase (Egl). The entire gene for the enzyme harbored a 2,472-bp open reading frame (ORF) encoding 824 amino acids, including a 30-aminoacid signal peptide. The deduced amino acid sequence of the mature enzyme (794 amino acids, 88,284 Da) showed very high similarity to those of family 5 mesophilic, alkaline Egls from some alkaliphilic bacilli. The enzyme had a region similar to a novel cellulose binding domain proposed for an Egl (EngF) from Clostridium cellulovorans. Expression of the Bacillus Egl gene in Bacillus subtilis resulted in high carboxymethy cellulase activity (2.0 g/l) in the culture broth, concomitant with the appearance of a protein band on an SDS gel at 86 kDa. Site-directed mutagenesis delineated the importance of Arg111, His151, Glu190, His262, Tyr264, and Glu305 in catalysis and/or substrate binding of the enzyme.

Amino Acid Sequence↗
PubMed2000

Production of isopropyl cis-6-hexadecenoate by regiospecific desaturation of isopropyl palmitate by a double mutant of a Rhodococcus strain.

Resting cells of a double mutant noted as KSM-MT66, derived from Rhodococcus sp. strain KSM-B-3 by UV irradiation, were found to cis-desaturate isopropyl hexadecanoate, yielding isopropyl cis-6-hexadecenoate. Addition of sodium glutamate (1.0%), Mg SO4 (2 mM), and thiamine (2 mM) increased the productivity of the unsaturated product in phosphate buffer. Optimal temperature and pH for the reaction were around 26 degrees C and 7, respectively. Under the optimized conditions, more than 50 g/l of isopropyl cis-6-hexadecenoate was produced after a 3-day incubation by resting cells of the mutant. Thus, cis-6-hexadecenoic acid, the main component of human sebaceous lipids, can be manufactured economically by the rhodococcal bioconversion.

Amino Acids↗
PubMed2000

Dehydroepiandrosterone suppresses elevated hepatic glucose-6-phosphatase mRNA level in C57BL/KsJ-db/db mice: comparison with troglitazone.

Dehydroepiandrosterone (DHEA) is known to improve hyperglycemia of diabetic C57BL/KsJ-db/db mice that are obese and insulin resistant. In a previous study, we reported that DHEA as well as troglitazone suppresses the elevated hepatic gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and fructose-1,6-bisphosphatase (FBPase) activities in C57BL/KsJ-db/db mice. In the present study, we evaluated the changes in mRNA of G6Pase and FBPase in db/db mice. Despite hyperinsulinemia, the G6Pase mRNA level of db/db mice was elevated as compared to their heterozygote littermate db/+m mice. In contrast, the FBPase mRNA level was not elevated in db/db mice. Administration of DHEA for two weeks significantly decreased the blood glucose level and the elevated G6Pase mRNA level in db/db mice. No significant changes were seen in the FBPase mRNA level after the administration of DHEA. Administration of troglitazone also decreased the blood glucose and G6Pase mRNA level in db/db mice although no changes were seen in the FBPase mRNA level. These results suggest that the elevation of G6Pase mRNA is important in elucidating the cause of insulin resistance, and that the G6Pase gene is at least one target for the hypoglycemic effects of DHEA as an insulin sensitizing agent in db/db mice.

Animals↗
PubMed2000

Magnetic resonance coronary angiography in patients with ischemic heart disease: analysis of coronary arterial blood flow velocity pattern.

Only a few reports evaluating coronary arterial blood flow velocity patterns using magnetic resonance (MR) coronary angiography have appeared to date. This study reports an evaluation of coronary arterial blood flow velocity patterns in patients with ischemic heart disease and in healthy subjects using MR coronary angiography. The subjects consisted of 20 patients with ischemic heart disease (IHD group) and 20 normal healthy subjects (N group). Using the fCARD PC method, ECG-gated MR coronary angiography was performed using an anteroposterior opposing phased array coil. Regions of interest were placed on bilateral coronary arteries to measure coronary arterial blood flow velocity patterns. The IHD group was divided into two subgroups, based on the presence (MI group) or absence (AP group) of infarcted myocardium using 99m Tc-methoxyisobutylisonitrile (MIBI) myocardial scintigraphy. Average diastolic peak velocity (ADPV) was lower in the IHD group than in the N group. In addition, the diastolic / systolic velocity ratio (DSVR) was significantly lower in the MI group. Moreover, in the AP group, both the ADPV and DSVR values were significantly increased in those who had undergone percutaneous transluminal coronary angioplasty postoperatively. Different from the Doppler guidewire method, MR coronary angiography facilitates noninvasive evaluation of coronary arterial blood flow velocity. Therefore, these results indicate that MR coronary angiography represents a potentially useful technique for diagnosing lesions of coronary arteries and evaluating their functions. This noninvasive method can be expected to replace the invasive Doppler guidewire method in the near future with development of MR coronary angiography technology.

Aged↗
PubMed2000

Patient with atrioventricular node reentrant tachycardia with eccentric retrograde left-sided activation: treatment with radiofrequency catheter ablation.

We describe a patient with supraventricular tachycardia with triple atrioventricular (AV) node pathway physiology. A discontinuous curve was present in the antegrade AV nodal function curves. During right ventricular pacing, the earliest retrograde atrial activation was recorded at the left-sided coronary sinus electrode. The retrograde ventricular-atrial interval was long and had decremental conduction. We induced a slow-slow AV node reentrant tachycardia (AVNRT) with eccentric retrograde left-sided activation. After slow pathway ablation, dual AV nodal pathway physiology was present. AVNRT with eccentric retrograde left-sided activation is relatively rare, and our findings suggest that eccentric retrograde left-sided atrial inputs consist partially of a slow pathway and disappear with slow pathway ablation.

Atrial Function, Left↗
PubMed2000

Development of non-bacterial thrombotic endocarditis after percutaneous transvenous mitral commissurotomy for severely calcified mitral stenosis.

We encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC.

Aged↗
PubMed2000

Choice of breastfeeding and physicians' advice: a cohort study of women receiving propylthiouracil.

OBJECTIVE: To examine the gap between the current social/medical practice and the evidence-based recommendation in favor of breastfeeding during maternal propylthiouracil (PTU) therapy. DESIGN: Prospective, observational, cohort study. SUBJECTS: Women requiring PTU during pregnancy, and endocrinologists and family physicians in Ontario, Canada. INTERVENTIONS: Questionnaire. MAIN OUTCOME MEASURES: Women were interviewed postpartum regarding their choice of infant feeding method and relevant advice received from physicians. Physicians were questioned about their advice to nursing women receiving PTU. RESULTS: Of 78 women, 66 had live births. Thirty-six required PTU postpartum (group 1), and 30 did not (group 2). Thirty-six healthy women served as controls (group 3). Breastfeeding initiation rates for groups 1, 2, and 3 were 44%, 83%, and 83%, respectively. In group 1, 15 women who breastfed received advice from 22 physicians regarding breastfeeding (20 in favor, 1 against, and 1 equivocal). Eleven who formula fed received advice from 17 physicians (4 in favor, 12 against, and 1 equivocal). A logistic regression analysis of group 1 showed that physicians' advice was the only significant predictor of the woman's choice to breastfeed during PTU therapy (relative risk: 5.48; 95% confidence interval: 1.28-23.40). The physician survey showed that 44% of endocrinologists do not recommend breastfeeding during PTU therapy. CONCLUSIONS: A substantial proportion of the lactating patients on PTU still receive advice against breastfeeding from their physicians. Physicians' advice and attitudes toward breastfeeding during PTU therapy are a major factor in women's final decision to breastfeed. Physicians' compliance with evidence-based data will facilitate breastfeeding in this group.propylthiouracil, breastfeeding, decision-making.

Attitude of Health Personnel↗
PubMed2000

Dietary sugar beet fiber ameliorates diarrhea as an acute gamma-radiation injury in rats.

Gamma radiation induces diarrhea as an acute injury. We have studied whether ingestion of sugar beet fiber influences radiation-induced diarrhea. Abdominal irradiation with gamma rays induced diarrhea in male Wistar/ST rats from 2 to 7 days after a single sublethal dose. The body weight of the irradiated rats was decreased temporarily at 4 days after irradiation regardless of the ingestion of sugar beet fiber. At day 8, it returned to almost the same level as that of unirradiated rats. A change in daily food intake resulted in a pattern similar to that for body weight. Dietary sugar beet fiber had little significant effect on the changes in body weight and daily food intake, and its ingestion significantly decreased gamma-ray-induced diarrhea. Changes in biochemical and histological parameters in intestinal mucosa (small intestine, cecum and colon) were not greatly influenced by the ingestion of sugar beet fiber through the periods of diarrhea. It was concluded that dietary sugar beet fiber ameliorated the diarrhea induced by abdominal irradiation. We suggest that the inhibitory effect of the ingestion of sugar beet fiber is due to its effects on the luminal environment, such as support for bacterial function in the luminal contents in the colon of animals that ingest sugar beet fiber.

Abdomen↗
PubMed2000

Effect of intrathecal nocistatin on the formalin-induced pain in mice versus that of nociceptin/orphanin FQ.

The effect of intrathecal nocistatin on formalin-induced pain in mice was investigated and compared with that of nociceptin/orphanin FQ (Noc/OFQ) to get information on the functional relationship between nocistatin and Noc/OFQ in the spinal cord. Subcutaneous injection of formalin into the hindpaw induced biphasic pain behaviors. Nocistatin, 1 pg, given intrathecally 1 min before 2% formalin injection, significantly attenuated the first phase of the formalin-induced pain. Also, 10 to 1000 pg of nocistatin, given 10 min after formalin injection, significantly inhibited the second phase of the formalin test. Naloxone, 5 mg/kg i.p., failed to antagonize inhibitory effects of nocistatin on either phase of the formalin-induced pain, indicating that analgesic effects of nocistatin were unrelated to the classic opioid system. At 1 to 100 pg, Noc/OFQ exerted no influence on either phase of the 2% formalin-induced pain. However, at 1% formalin, Noc/OFQ significantly aggravated the second phase at 10 pg but not the first phase at 1 to 1000 pg. This aggravating effect of Noc/OFQ was completely reversed by 10 pg of nocistatin. At 0.3 and 1 microg, Noc/OFQ, but not nocistatin, significantly inhibited both phases of the 2% formalin-induced pain. Suppressive effects of 1 microg of Noc/OFQ on the formalin-induced pain were not affected by 1 microg of nocistatin. These results suggest that Noc/OFQ might be involved in the second phase of the mouse formalin test and that, under such pathophysiological conditions, nocistatin could exhibit antagonism against Noc/OFQ at the spinal level.

Animals↗
PubMed2000

[Chronic subdural hematoma associated with malignancy: report of three cases].

Three cases of chronic subdural hematoma (CSH) associated with malignancy are reported. Case 1; A one-year-old girl was referred for vomiting and convulsions. Left CSH was removed, and her symptoms disappeared. Cytological examination of chronic subdural hematoma revealed abnormal white blood cells. A clinical diagnosis of acute monocytic leukemia was made after the laboratory examination. Remission was achieved by chemotherapy, but she died one year after the operation. Case 2; A 72-year-old woman was referred for right hemiparesis and urinary incontinence. Left CSH was irrigated, and her clinical symptoms immediately disappeared. Cytological examination of chronic subdural hematoma revealed abnormal white blood cells. A clinical diagnosis of chronic lymphocytic leukemia was made after the laboratory examination. No treatment was given since there were no clinical symptoms of chronic lymphocytic leukemia. Case 3; A 70-year-old woman who had been affected with early gastric cancer and mammary cancer for the previous two years was admitted to our clinic because of headache, right hemiparesis and consciousness disturbance. Left CSH was irrigated, and her clinical symptoms improved. However, there was a tendency to bleed because disseminated intravascular coagulation had occurred, and CT showed bilateral subdural hematoma. A second irrigation was performed, but her symptoms did not improve. Left acute subdural hematoma, which was removed by craniotomy, occurred three days after the second operation. Pathological examination of the outer membrane of the subdural hematoma revealed invasion of adenocarcinoma. She died three days after the third operation. It is recommended that both the cytological and the histological examinations be performed when possible, since they are simple to perform and very useful in some cases.

Adenocarcinoma↗
PubMed2000

Accumulation of cAMP evoked by acetylcholine stimulation in rat submandibular acinar cells: observation of exocytosis, fluid secretion and [Ca2+]i.

The effects of cAMP accumulation evoked by acetylcholine (ACh) stimulation were studied in rat submandibular acinar cells by observing the exocytotic events, swelling of intercellular canaliculi (IC) and intracellular Ca2+ concentration ([Ca2+]i), which were monitored using an optical microscope. ACh stimulation evoked transient increases followed by sustained increases in the frequency of exocytotic events and IC swelling, while isoproterenol (isoprenaline; IPR) stimulation evoked sustained increases in these parameters. BAPTA treatment reduced the frequency of exocytotic events evoked by 5 microM ACh in the absence of extracellular Ca2+, and further addition of Rp-cAMPS or H-89 (protein kinase A (PKA) inhibitors) eliminated the remaining ACh-evoked responses (50 %). Addition of PKA inhibitors in the presence of extracellular Ca2+ reduced the frequency of exocytotic events evoked by 500 microM ACh in non-BAPTA-loaded cells. However, IC swelling evoked by 5 microM ACh was not affected by addition of PKA inhibitors, and was eliminated in BAPTA-loaded cells perfused with Ca2+-free solution. These results indicate that the IC swelling is regulated by [Ca2+]i and the frequency of exocytotic events is regulated by both [Ca2+]i and [cAMP]i during ACh stimulation. Addition of H-89 inhibited the capacitative Ca2+ entry into ACh-stimulated acinar cells. Biochemical analysis revealed that ACh stimulation increased the cAMP content in perfused submandibular glands. These results indicate that ACh stimulates the accumulation of cAMP in submandibular acinar cells and that this accumulation of cAMP modulates Ca2+-regulated exocytosis.

Acetylcholine↗
PubMed2000

[DNA diagnosis of alpha-herpesvirinae infection].

Herpesviruses have a characteristic of the latency after the primary infection. Advanced study on the causal relation between the reactivation of latent virus and the appearance of the symptoms would need both of the detection of viral genome by the DNA diagnosis method and the analysis of the kinetics of the virus. We developed a new quantitative method for the detection and the titration of copy number in the viral genome using the combination of polymerase chain reaction and microplate hybridization. The availability of the method was confirmed by the several cases of alpha-herpesvirinae infections.

Alphaherpesvirinae↗
PubMed2000

Expression of N-acetylglucosaminyltransferase V in colorectal cancer correlates with metastasis and poor prognosis.

N-Acetylglucosaminyltransferase V (GnT-V) is an enzyme that catalyzes beta 1-6 branching of N-acetylglucosamine on asparagine-linked oligosaccharides of cell proteins. Metastatic potential of various cancer cells has been shown to correlate with increase of GnT-V activity and concomitant beta 1-6 branching of N-acetylglucosamine. However, protein expression of GnT-V in human cancer tissue and its clinical significance have not yet been demonstrated. To clarify the possible relationship between metastasis and GnT-V in human colorectal cancer, protein expression of GnT-V was studied using surgically resected specimens. We established a monoclonal antibody against GnT-V and performed immunohistochemical analysis of 103 human colorectal cancer cases. Of 103 cases, 26 cases (25.2 %) showed specific expression of GnT-V in colorectal cancer tissues. The expression of GnT-V was significantly correlated with distant metastasis (P < 0.05, chi2 test). Overall 5-year survival rate was 52.8% for GnT-V-positive patients and 81.7% for GnT-V-negative patients (P < 0.01, Log-rank test). We showed direct evidence for the relationship between GnT-V and metastasis in human colorectal cancer. Screening of GnT-V expression in colorectal cancer may provide useful information for prognosis of postoperative patients.

Aged↗
PubMed2000

Clinical significance of anticentromere antibodies in patients with systemic lupus erythematosus.

OBJECTIVE: To clarify the clinical significance of anticentromere antibodies (ACA) in patients with systemic lupus erythematosus (SLE). METHODS: Two hundred sixteen patients with SLE who were treated in our department were surveyed cross sectionally for the presence of ACA using indirect immunofluorescence on HEp-2 cell lines. ACA were identified by their discrete speckled pattern. Antibodies to the major centromere protein, CENP-B, were also studied with ELISA. Serial determinations of anti-CENP-B were carried out using stored serum samples, if available. RESULTS: ACA were recognized in 12 (5.6%) patients with SLE. All patients were receiving steroid therapy, with a mean dose of prednisolone of 14.4 mg/day. These patients also tested positive for anti-CENP-B with high titers despite the low serological disease activity in most. Three or more CREST features were observed in 2 patients and 2 others had no such features. Both patients without CREST features had a relatively short disease duration. The age at onset of SLE was significantly higher and Raynaud's phenomenon was more frequent in patients with ACA than in patients without ACA. In 8 of 10 patients tested, retrospective analysis using stored sera revealed no consistent change in anti-CENP-B titers over time. CONCLUSION: The presence of ACA in patients with SLE is apparently more frequent than previously believed. Patients with SLE with ACA may be a distinct subgroup. A longterm followup is warranted to fully determine the clinical significance of ACA in patients with SLE.

Adolescent↗
PubMed2000

Thrombopoietin enhances neutrophil production by bone marrow hematopoietic progenitors with the aid of stem cell factor in congenital neutropenia.

We examined the effects of granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), and thrombopoietin (TPO), alone or in combination, on the generation of neutrophils by bone marrow (BM) cells from three patients with severe congenital neutropenia (SCN) through the use of a serum-deprived liquid culture system. Synergistic effects of G-CSF and SCF on the neutrophil production by BM CD34+CD38+c-kit+ cells were observed in SCN patients as well as in normal controls. The addition of TPO to the culture containing G-CSF and SCF further augmented the growth of neutrophils in the two groups. Single-cell culture experiments revealed that the three-factor combination caused increases in both the number and size of neutrophil colonies compared with G-CSF + SCF in normal BM cells, whereas only a significant increment in the colony size was observed in SCN patients. Even in the presence of SCF or SCF + TPO, the concentrations of G-CSF necessary for the substantial production of neutrophils by CD34+CD38+c-kit+ cells were higher in two patients compared with the levels obtained by normal control cells. In addition, TPO did not accelerate the maturation of neutrophilic cells supported by G-CSF + SCF. When BM CD34+CD38-c-kit+ cells were targeted, the addition of TPO to the culture containing G-CSF and SCF was required for significant neutrophil colony growth in the two groups. These results suggest that TPO enhances the G-CSF-dependent neutrophil production with the aid of SCF in this disorder.

ADP-ribosyl Cyclase↗
PubMed2000

Efficacy of directional coronary atherectomy before stent implantation for coronary ostial lesions.

We evaluated stent implantation following directional coronary atherectomy (DCA) for coronary ostial lesions. The subjects were 27 patients (27 lesions) who underwent stent deployment after DCA, and 47 patients (47 lesions) who underwent stent deployment alone as the control group. There were no differences in numbers of lesions with multi-vessel disease, left anterior descending artery lesions, de novo lesions or reference vessel diameters in the two groups. The percent diameter stenosis after stent implantation was lower in the DCA-stent group than in the stent-alone group (9 +/- 10% versus 17 +/- 14%, respectively; p < 0.01). The initial procedural success rate was 92.6% in the DCA-stent group and 91.4% in the stent-alone group. The initial clinical success rate was 100% in the DCA-stent group and 95.7% in the stent-alone group. The restenosis rate was lower in the DCA-stent group (20% versus 43% in the stent-alone group). This study showed that debulking by DCA before stenting is more effective compared to stenting alone.

Aged↗
PubMed2000

Which drugs are contraindicated during breastfeeding? Practice guidelines.

QUESTION: Many breastfeeding mothers are concerned about taking medications that might affect their babies. Are there any guidelines on which drugs are safe? ANSWER: Only a few drugs pose a clinically significant risk to breastfed babies. In general, antineoplastics, drugs of abuse, some anticonvulsants, ergot alkaloids, and radiopharmaceuticals should not be taken, and levels of amiodarone, cyclosporine, and lithium should be monitored.

Anticonvulsants↗