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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 181 records · Page 10Linked to original sources
PubMed1996

Larvicidal activity of Bacillus thuringiensis natural isolates; indigenous to Japan, against two nematoceran insect pests occurring in urban sewage environments.

A total of 1449 Bacillus thuringiensis strains, indigenous to Japan, were screened for larvicidal activity against two nematoceran insect pests, the mosquito, Culex pipiens molestus (Culicidae), and the moth-fly, Telmatoscopus albipunctatus (Psychodidae). Mosquito specific strains were abundant in H serotypes 3abc (serovar kurstaki), 3ade (fukuokaensis), 4ac (kenyae), 7 (aizawai), 11ac (kyushuensis) and 29 (amagiensis), while moth-fly specific strains were predominantly found in H serotype 17 (tohokuensis). Strains toxic to both insects were most frequently detected in H serotypes 10 (darmstadiensis) and 17/27. Seven selected B. thuringiensis strains were highly toxic to Culex and/or Telmatoscopus. There was a diversity in SDS-PAGE profiles of inclusion proteins of these strains.

Animals↗
PubMed1996

Intestinal absorption barriers and transport mechanisms, including secretory transport, for a cyclic peptide, fibrinogen antagonist.

PURPOSE: The intestinal absorption of DMP 728, a cyclic peptide fibrinogen antagonist, was examined with the goals of identifying the cause(s) of its low oral bioavailability and understanding the mechanisms of its intestinal transport. METHODS: In vitro partitioning, metabolism, and permeation through rat intestinal segments were evaluated. RESULTS: DMP 728 had low lipophilicity and low intestinal permeation rates relative to model compounds. In addition, DMP 728 in vitro intestinal permeation in the secretory direction greatly exceeded transport in the absorptive direction. The secretory transport was saturable, glucose-dependent, and was inhibited by verapamil and by a monoclonal antibody to P-glycoprotein. DMP 728 likewise inhibited the secondary transport of verapamil. Mucosal-to-serosal permeation rates increased in going from the proximal to distal intestinal sites, but were lower than serosal-to-mucosal permeation rates for each site. CONCLUSIONS: Net secretory transport and low lipophilicity are the major barriers to absorption of DMP 728.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Direct and indirect association of the small GTPase ran with nuclear pore proteins and soluble transport factors: studies in Xenopus laevis egg extracts.

Ran is a small GTPase that is required for protein import, mRNA export, and the maintenance of nuclear structures. To gain a better understanding of Ran's role in the nucleus, we have sought to use Xenopus egg extracts for the purification and characterization of proteins from egg extracts bound with a high affinity to a glutathione-S-transferase-Ran fusion protein (GST-Ran). We found that GST-Ran associates specifically with at least 10 extract proteins. We determined the identifies of six Ran-interacting proteins (Rips), and found that they include RanBP2/Nup358, Nup153, Importin beta, hsc70, RCC1, and RanBP1. On the basis of peptide sequence, a seventh Rip (p88) seems to be similar but not identical to Fug1/RanGAP1, the mammalian Ran-GTPase-activating protein. Gel filtration analysis of endogenous extract proteins suggests that Importin beta acts as a primary GTP-Ran effector. Both Ran and Importin beta are coimmunoprecipitated by anti-p340RanBP2 antibodies in the presence of nonhydrolyzable GTP analogues, suggesting that Ran-Importin beta complexes interact with p340RanBP2. Two other Rips, p18 and p88, are coprecipitated with p340RanBP2 in a nucleotide-independent manner. Analysis of the Ran-GTPase pathway in Xenopus extracts allows the examination of interactions between Ran-associated proteins under conditions that resemble in vivo conditions more closely than in assays with purified components, and it thereby allows additional insights into the molecular mechanism of nuclear transport.

Amino Acid Sequence↗
PubMed1996

Clinical effects and pharmacokinetics of a single oral dose of pirmenol hydrochloride.

To establish the clinical efficacy of a single oral dose of pirmenol, we evaluated electrophysiologic and hemodynamic effects simultaneously after drug administration, performing electrophysiologic testing in 20 patients with ECG-documented paroxysmal supraventricular tachycardia (PSVT) before and after a single oral 200-mg dose of pirmenol. Hemodynamic measurements were made with a Swan-Ganz catheter in the first 10 consecutive patients. In a different series of patients, we administered a single 200-mg oral dose of pirmenol to evaluate its acute termination effect in 7 patients with PSVT and 9 with paroxysmal atrial fibrillation. Pirmenol prolonged the refractory period of the retrograde conduction system in patients with or without an accessory pathway, and supraventricular tachycardia was no longer inducible at 60 min in 11 patients [8 of 11 with atrioventricular (AV) reentrant tachycardia and 3 of 5 with AV nodal reentrant tachycardia]. Pirmenol increased the heart rate (p < 0.01) and total systemic resistance (p < 0.05), and reduced the stroke volume index (p < 0.01), all significantly. The plasma concentration of pirmenol at 1 h after administration was 0.75 +/- 0.48 microgram/ml. A single oral dose of pirmenol during tachyarrhythmia successfully restored sinus rhythm in 4 of 7 (57%) patients with PSVT and 4 of 9 (44%) patients with paroxysmal atrial fibrillation. A single oral dose of pirmenol was well tolerated as episodic treatment in patients with supraventricular tachyarrhythmias.

Administration, Oral↗
PubMed1996

Addition of nucleotides similar to deleted CAA repeats in the 5' non-coding region of tomato mosaic virus RNA following propagation.

Previously we made a series of deletion mutants in the 5' non-coding region of tomato mosaic tobamovirus (ToMV) RNA and checked their ability to replicate in tobacco protoplasts. Long deletions in this region caused the virus to lose the ability to replicate. Several mutants with deletions of about 10 nucleotides (short deletion mutants; SDM) retained the ability to replicate. In this study, we inoculated SDMs onto systemic host plants and observed their symptoms. One mutant (19/32) caused severe mosaic symptoms on some tobacco plants (Nicotiana tabacum cv. Samsun) but no symptoms on others. Virus accumulation in 19/32-inoculated plants paralleled the severity of symptoms. Four CAA repeat sequences were deleted in 19/32. Progeny 19/32 from plants showing severe systemic mosaic symptoms had acquired additional nucleotides in this region. We conclude that the CAA repeat sequence is related to the fitness of the virus population to replicate in whole plants rather than to translation of ToMV replicase genes.

Animals↗
PubMed1996

Changes in autonomic activity preceding onset of nonsustained ventricular tachycardia.

BACKGROUND: The triggering role of the autonomic nervous system in the initiation of ventricular tachycardia has not been established. To investigate the relationship between changes in autonomic activity and the occurrence of nonsustained ventricular tachycardia (NSVT) we examined heart rate variability (HRV) during the 2-hour period preceding spontaneous episodes of NSVT. Twenty-four subjects were identified retrospectively as having had one episode of NSVT during 24-hour Holter ECC recording. METHODS: We measured the mean interval between normal heats (meanRR), the standard deviation of the intervals between beats (SD), the percentage of counts of sequential intervals between normal beats with a change of >50 ms (%RR50), the logarithms of low- and high-frequency spectral components (lnLF, lnHF) of HRV for sequential 10-minute segments preceding NSVT. The correlation dimension (CDim) of HRV was calculated similarly for sequential 20-minute segments. We assessed the significance of the time-course change of each marker over the 120-minute period prior to NSVT onset. RESULTS: MeanRR (P < 0.05), lnLF (P < 0.0001), lnHF (P < 0.0001), the natural logarithm of the ratio of LF to HF (ln[LF/HF]; P < 0.05), and CDim (P < 0.05) showed significant time-course changes during that period, while SD and %RR50 did not. MeanRR, lnLF, lnHF, and CDim all decreased prior to the onset of NSVT, whereas ln(LF/HF) increased. We divided the subjects into two groups: one consisting of 12 patients with coronary artery disease; and the second group of 12 patients without known coronary artery disease. Both groups showed significant changes (P < 0.05) of CDim, lnLF, and lnHF preceding the episodes of NSVT. CONCLUSIONS: Changes in the pattern of HRV prior to the onset of episodes of NSVT suggest that changes in autonomic activity may commonly play a role in the triggering of spontaneous episodes of NSVT in susceptible patients. The measured changes suggest a reduction in parasympathetic activity, perhaps in conjunction with an increase in sympathetic activity, may trigger NSVT.

Adult↗
PubMed1996

Identification of overlapping DNA-binding and centromere-targeting domains in the human kinetochore protein CENP-C.

The kinetochore in eukaryotes serves as the chromosomal site of attachment for microtubules of the mitotic spindle and directs the movements necessary for proper chromosome segregation. In mammalian cells, the kinetochore is a highly differentiated trilaminar structure situated at the surface of the centromeric heterochromatin. CENP-C is a basic, DNA-binding protein that localizes to the inner kinetochore plate, the region that abuts the heterochromatin. Microinjection experiments using antibodies specific for CENP-C have demonstrated that this protein is required for the assembly and/or stability of the kinetochore as well as for a timely transition through mitosis. From these observations, it has been suggested that CENP-C is a structural protein that is involved in the organization or the kinetochore. In this report, we wished to identify and map the functional domains of CENP-C. Analysis of CENP-C truncation mutants expressed in vivo demonstrated that CENP-C possesses an autonomous centromere-targeting domain situated at the central region of the CENP-C polypeptide. Similarly, in vitro assays revealed that a region of CENP-C with the ability to bind DNA is also located at the center of the CENP-C molecule, where it overlaps the centromere-targeting domain.

Amino Acid Sequence↗
PubMed1996

Enzymes in intestinal juice from patients with liver diseases and colon polyps: measurement of bilirubin, alkaline phosphatase, aspartate aminotransferase and lactate dehydrogenase.

Since the amounts of hepatogenous enzymes discharged into the intestinal tract remain unknown, this study was initiated to evaluate the amounts of the enzymes in the intestinal tract. Whole gut lavage fluid (polyethyleneglycol electrolyte solution) was administered orally to 42 subjects, consisting of 5 patients with hepatoma, 10 with chronic hepatitis, 10 with colon polyps, and 17 control subjects without liver disease. Two hr after the large intestinal lavage, the digestive tract juice was aspirated by colonoscopy, and the bilirubin (Bil), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the aspirates were measured. A positive correlation between the AST and LDH values was found, and a significant difference in these values between the hepatic disorders and the normal controls was noticed. A significant positive correlation between the ALP and Bil values was found, and a statistical difference in these values between the group of colon polyps and the controls and other groups was observed. This lavage fluid technique enables to estimate the amounts of hepatic enzymes discharged into the intestinal tract, thereby opening a new avenue for future enzyme research.

Adult↗
PubMed1996

Partial deficiency of phosphoglycerate mutase with diabetic polyneuropathy: the first Japanese patient.

We report here findings in a 51-year-old Japanese man with non-insulin-dependent diabetes mellitus who complained of exercise-induced cramps. Muscle biopsy showed scattered regenerating fibers, small angular fibers and increased PAS positive particles. Electron microscopic examination revealed an abnormal accumulation of glycogen particles in subsarcolenmmal areas and between myofibrils while chemical studies showed an increased glycogen concentration and decreased phosphoglycerate mutase (PGAM), 46.9% of the normal mean value. Thus, partial PGAM deficiency, insulin resistance and mild diabetic sensory-motor polyneuropathy can induce severe cramps.

Biopsy↗
PubMed1996

Phase II study of DTIC, ACNU, and vincristine combination chemotherapy for supratentorial malignant astrocytomas.

This phase II clinical study evaluated the use of 5-(3-3'-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) pretreatment to reduce cellular resistance and enhance the antitumor effects of chloroethyl nitrosoureas in 32 patients with supratentorial malignant gliomas, including 13 anaplastic astrocytoma and 19 glioblastoma multiforme. All patients received a total dose of 50-65 Gy radiation therapy after surgery. Chemotherapy consisted of DTIC (1 mg/kg) on days 1-5, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (2 mg/kg) on day 5, and vincristine (0.02 mg/kg) on days 1 and 15 every 5 weeks. One patient achieved complete response and 12 patients showed partial response. Median survival time was 18 months and median time-to-progression was 11 months. No significant toxicity was encountered. There was no significant benefit of this pretreatment to combination chemotherapy when compared with previous results. This study does not support a further role for DTIC as a depleter of O6-alkylguanine deoxyribonucleic acid alkyltransferase activity preceding chloroethyl nitrosourea-based chemotherapy.

Adolescent↗
PubMed1996

Serum G-CSF levels in primary myelofibrosis and chronic neutrophilic leukemia as estimated by the highly sensitive chemiluminescence enzyme immunoassay (CLEIA).

We previously reported that serum granulocyte colony stimulating factor levels of chronic myelogenous leukemia patients in chronic phase (CP) are significantly lower than those of healthy persons or other hematological malignancies as assessed by chemiluminescence enzyme immunoassay (CLEIA). In this study, we clarify the difference in serum G-CSF levels between patients with primary myelofibrosis (PMF, myelofibrosis with myeloid metaplasia; MMM) and those with secondary myelofibrosis caused by several hematological disorders, using the same highly sensitive CLEIA method. It is clearly demonstrated that serum G-CSF levels of the patients with PMF and chronic neutrophilic leukemia (CNL) are extremely low, similar to those in patients with CML in CP in this study. From these data, it is speculated that the abnormal proliferation of granulocytes in PMF and CNL may not be due to the stimulation by G-CSF, and that a negative feedback mechanism might exist between peripheral granulocytes and serum G-CSF.

Biomarkers↗
PubMed1996

Ruptured aneurysm of the middle meningeal artery associated with occlusion of the posterior cerebral artery. Case report.

The authors describe the case of a 69-year-old man with an intracerebral hemorrhage due to rupture of a nontraumatic aneurysm of the middle meningeal artery (MMA). The ipsilateral posterior cerebral artery (PCA) was occluded, and dural anastomoses developed as the main collateral pathway between the MMA and the cortical branch of the PCA, on which the aneurysm was located. It is considered that increased hemodynamic stress to the collateral pathway contributed to the formation of the aneurysm.

Aged↗
PubMed1996

Multicenter evaluation of a colorimetric microplate antimycobacterial susceptibility test: comparative study with the NCCLS M24-P.

A colorimetric test method using the microplate culture technique for the determination of susceptibility of Mycobacterium tuberculosis against antimycobacterial agents was developed and evaluated by the multicenter study. The test method utilizes an oxidation-reduction dye, 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC), as an indicator of mycobacterial growth. When compared to the presently available test method, some modifications were also included; lower inoculum density (10-fold dilution), inclusion of an inoculum diluted 1:100 as a growth control, and the preparation of inoculum preincubated in Middlebrook 7H9 broth and spectrophotometrically adjusted to McFarland #1 turbidity. The test method evaluated was highly precise and reliable to detect antimycobacterial resistances when the ATCC reference strains were tested. Also, the interpretations of the test result were highly comparable to those determined by the method of NCCLS M24-P, the % agreements ranging from 76.1% (ethambutol) to 91.3% (streptomycin). The test results were also comparable to those determined by Ogawa media; > 90% agreed with susceptible, intermediate, or resistant. The appearance of mycobacterial colonies on the test media was easily read, and the test results were more comparable to those of NCCLS M24-P. With these results, it can be concluded that the colorimetric microplate susceptibility test method described will be more suitable for clinical mycobacteriology laboratories.

Antitubercular Agents↗
PubMed1996

[Malignant fibrous histiocytoma of spermatic cord: a case report].

A 52-year-old man presented with a painful, gradually enlarging mass in the left inguinal region. An ultrasound examination demonstrated a lobulated, heterogenous tumor 6.0 x 4.0 x 3.0 cm in diameter, which separated from the left testis and epididymis. Radical inguinal orchiectomy with wide en bloc local resection was performed. Histologic diagnosis was a malignant fibrous histiocytoma (MFH) with a giant cell variant. The patient underwent postoperative regional irradiation and has been alive without metastasis and local recurrence 3 months after the operation. Among the 19 patients with MFH of spermatic cord reported in Japan, only two cases were of giant cell type of MFH including the present case.

Genital Neoplasms, Male↗