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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 109 records · Page 6Linked to original sources
PubMed1999

[QT dispersion in premature beats produced by extrastimuli from the right atrium and right ventricle].

The difference between the maximum and minimum QT interval measured from a 12-lead electrocardiogram was defined as an index of spatial inhomogeneous repolarization of the ventricular myocardium. The causal relationship between QT dispersion and incidence of ventricular arrhythmias has been pointed out in various heart diseases, but until now it was discussed mainly related to sinus rhythm. QT dispersion in extrasystole may be more important in the development of arrhythmias. We examined 5 cases (mean age 34 +/- 12 years) with a history of paroxysmal supraventricular tachycardia, who underwent electrophysiologic study. Both atrial and ventricular premature stimuli were given at a basic cycle length of 600 msec respectively. The QT interval and the ventricular activation time (VAT) (period from premature test stimulus to the summit of QRS) of the premature beats were measured in a simultaneously recorded 12-lead electrocardiogram. QT dispersion (the difference between the longest QT interval and the shortest QT interval) and VAT dispersion (the difference between the longest VAT and the shortest VAT) were measured. In atrial premature beats, there were no significant changes in the QT dispersion or VAT dispersion when the coupling interval of the premature beats was shortened. In the ventricular premature beats, however, both the QT dispersion and the VAT dispersion tended to increase with the shortening of the coupling interval. We concluded that only a short coupled ventricular premature beat induces greater QT and VAT dispersion. A ventricular couplet with short coupling interval may contribute to the development of ventricular tachyarrhythmias.

Adult↗
PubMed1999

Insulin-like growth factor binding protein-1 as a predictor of glucose-stimulated hyperinsulinemia in prepubertal obese children.

OBJECTIVE: The present study was undertaken to examine the association of a glucose-stimulated insulin response with the fasting insulin-like growth factor-binding protein (IGFBP)-1 concentration in prepubertal obese children. SUBJECTS AND METHODS: The fasting levels of serum insulin and IGFBP-1 were measured in 17 obese and 16 control children. Furthermore, we performed an oral glucose tolerance test in obese children and examined the association of the area under the curve (AUC) for insulin with the fasting IGFBP-1 level. RESULTS: The mean serum level of IGFBP-1 was significantly lower in obese children (41.0 +/- 4.8 micrograms/l. P < 0.005) than in controls (91.2 +/- 9.9 micrograms/l). Although there was an inverse relationship between the fasting levels of serum insulin and IGFBP-1 in all subjects (r = -0.42, P < 0.05), no significant correlation between these two parameters was observed in the obese group alone. In obese children, the fasting IGFBP-1 level correlated inversely with AUC-insulin (r = -0.70, P < 0.005), whereas there was no significant relationship between the fasting insulin level and AUC-insulin. CONCLUSION: The present study suggests that the serum level of IGFBP-1 may be an early predictor of insulin resistance in prepubertal obesity.

Area Under Curve↗
PubMed1999

The phosphorylation status of insulin-like growth factor-binding protein-1 in prepubertal obese children.

OBJECTIVE: We measured the total and nonphosphorylated insulin-like growth factor-binding protein (IGFBP)-1 concentrations in obese children to determine the effect of obesity on the status of IGFBP-1 phosphorylation. We also measured the serum levels of insulin, total and free IGF-I, and IGFBP-3 to investigate their relationships to the IGFBP-1 phosphorylation status in obese subjects. SUBJECTS AND METHODS: Nineteen prepubertal obese and 15 age-matched control children were included in the study. The serum levels of total and nonphosphorylated IGFBP-1 were determined by noncompetitive RIAs. RESULTS: The serum levels of total and nonphosphorylated IGFBP-1 were significantly lower in the obese group (48.7+/-5.6 microgram/l, P<0.001 and 11.1+/-1.9 microgram/l, P<0.01 respectively) than in the controls (86.7+/-9.0 microgram/l and 28.8+/-6.2 microgram/l respectively). However, the ratio of nonphosphorylated IGFBP-1 to total IGFBP-1 did not differ significantly between the obese and control groups. The circulating free IGF-I level was significantly higher in the obese children than in the controls (P<0.05), while the serum levels of insulin, total IGF-I and IGFBP-3 were not significantly different between the two groups. A stepwise regression analysis of the combined group revealed that only the total IGFBP-1 level was an independent predictor of the free IGF-I concentration (P<0.001). CONCLUSION: The present study shows that both total and nonphosphorylated IGFBP-1 concentrations are decreased in obese children and the increased free IGF-I level in obese children is related to the reduced total IGFBP-1 level, but unrelated to the change in the IGFBP-1 phosphorylation status.

Child↗
PubMed1999

[Aggressive angiomyxoma in the scrotum: a case report].

A case of aggressive angiomyxoma occurring in the scrotum is reported. A 57-year-old Japanese man presented with a 2-year history of non-tender soft mass in the scrotum. Computed tomography and magnetic resonance imaging revealed a well-defined mass 8 cm in diameter extending from the medial aspect of the left ischium. Angiography revealed faint vascularity fed by the left internal pudendal artery. Excision was performed by a scrotal approach, and histological examination confirmed an aggressive angiomyxoma. The patient showed no recurrence at 3 months follow-up.

Female↗
PubMed1999

[Acquired pulmonary stenosis caused by mediastinal mature teratoma: a case report].

A 13-year-old girl was admitted with a sudden onset of chest oppression. Mediastinal teratoma was suspected on chest X-ray and CT scan. A grade 2/6 systolic murmur was heard at the upper left sternal area and cardiac catheterization showed mild pulmonary stenosis. After resection of the tumor, the murmur disappeared and histopathological diagnosis was mature teratoma. This is a rare case report of pulmonary stenosis caused by mediastinal mature teratoma.

Adolescent↗
PubMed1999

Pharmacokinetics of etoposide after intrathoracic instillation to lung cancer patients with pleural effusion.

OBJECTIVE: To examine etoposide (VP16) levels in serum and pleural effusion after intravenous infusion or intrathoracic instillation to lung cancer patients. METHODS: Four patients were administered VP16 by intrathoracic instillation and three patients were administered it intravenously. Serum, urine, and pleural effusion were collected and VP16 levels in the biological fluids were determined by HPLC. Pharmacokinetic parameters were calculated. RESULTS: VP16 distributed rapidly into pleural effusion after intravenous infusion. In two of three patients, VP16 levels in pleural effusion were maintained at constant levels more than 24 hours in spite of the decline in serum VP16 levels. After intrathoracic instillation, VP16 in pleural effusion reached high levels and eliminated slowly. Serum levels of VP16 were relatively low compared with those in pleural effusion. CONCLUSION: It was demonstrated that intrathoracic instillation of VP16 might be useful for managing malignant pleural effusion and reducing systemic side-effects by cutting down the dose.

Adenocarcinoma↗
PubMed1999

[Detection size dependence of field factor for narrow beam].

An absorbed dose in the narrow beam is calculated based on the depth dose distribution and a field factor. The field factor has to be measured with especially high accuracy because it is highly variable. The field factor was calculated when detection size was changed, by using Monte Carlo simulation, which had no energy dependency or geometrical error. Then the relation between field factor and detection size in the narrow beam was investigated. An absorbed dose in peak depth and reference depth according to detection size was calculated for each field size. Detection size dependency was recognized in the case of measuring a field factor, because the absorbed dose tended to decrease as detection size increased. The absorbed dose in the narrow beam has to be calculated within a change of +/- 2%. The change in peak depth according to detection size was eliminated, and then the relation between an absorbed dose at the ideal detection size of 0 mm phi by extrapolation and detection size which has a deference of 2% from it, were acquired. In addition, the maximum usable detection size was estimated in the case of measuring the field factor.

Models, Theoretical↗
PubMed1999

[Renal glucosuria and membranous glomerulonephritis in chronic inflammatory demyelinating polyradiculoneuropathy: CIDP].

Glucosuria was detected in a 7-year-old boy by a routine school mass examination in April 1991. The diagnosis of renal glucosuria was made in the affiliated hospital of the University of Tsukuba. The patient developed muscle weakness and gait disturbance in February 1993. Spinal fluid examination revealed a protein level of 62 mg/dl and a cell count of 4/3. Under the diagnosis of Guillain-Barré syndrome, he was treated with i.v. immunoglobulin and oral prednisolone. Although the therapy somewhat improved the symptoms, his muscle strength had not fully recovered at the end of the treatment. In November 1995, the muscle weakness became worse; he could not go up stairs, nor stand upright on one leg. In April 1996, proteinuria was detected in a school mass examination. He was referred to the University Hospital of Tsukuba for a full renal study in March 1997. Renal biopsy revealed global sclerosis in 16 of 19 glomeruli with extensive interstitial fibrosis and mononuclear cell infiltration. A diagnosis of membranous glomerulonephritis was established based on the findings of spikes in PASM staining, weak IgG deposition in the glomerular capillary and subepithelial deposits by electron microscopic study. Additionally, pituitary growth hormone deficiency was found by endocrinological examination. The diagnosis of CIDP was established by fibulal neuron biopsy, which revealed neuronal degeneration and profound demyelinization. The clinical course of the present case was unlike that of the few reported cases of MGN associated with CIDP described in the literature. The initial renal symptom was glucosuria, which started 5 years prior to the onset of proteinuria. Second, glomerulosclerosis was more extensive than that seen in the literature. We surmise that chronic interstitial nephritis of insidious onset was followed by MGN which developed subsequently, probably at the time of the start of proteinuria.

Adolescent↗
PubMed1999

[Multicenter evaluation of broth microdilution test, BrothMIC MTB, to determine minimum inhibitory concentrations (MICs) of antimicrobial agents for Mycobacterium tuberculosis--evaluation of interlaboratory precision and interpretive compatibility with agar proportion method].

A newly developed microdilution antimycobacterial susceptibility test, BrothMIC MTB (Kyokuto Pharmaceutical Industrial Co., Ltd., Tokyo, Japan) to determine minimum inhibitory concentrations (MICs) was evaluated at multisites. The test method utilizes air-dried microplates containing serially diluted antimicrobial agents and the modified Middlebrook 7H9 broth. The eight antimycobacterial agents tested were rifampicin, isoniazid, ethambutol, streptomycin, kanamycin, levofloxacin, sparfloxacin and ciprofloxacin. The test plates were reconstituted by inoculation of 0.2 ml of cell suspensions (6 x 10(5) cells/ml) and were incubated at 36 degrees C in 5% to 10% CO2. The growth endpoints were visually read after 7-day and 10-day incubations. The reproducibility was evaluated with the four reference strains of Mycobacterium tuberculosis, and were compared with the agar proportion method described in the National Committee for Clinical Laboratory Standards (NCCLS) M24-T. Of the 1,022 testings of the reference strains, 1,020 (99.8%) of the MICs read after 7-day incubation fell within 3 log2 dilutions. The growth endpoints read after 7-day and 10-day incubations gave equal MIC ranges for the respective agents. The results obtained by the BrothMIC MTB for 93 clinical isolates of M. tuberculosis compared well with those determined by the NCCLS method with 98% to 99% agreements, except for ethambutol. According to the comparative analysis with the agar proportion method, the interpretive MIC breakpoints to discriminate between the isolates susceptible and resistant against the respective agents were proposed. In conclusion, this newly developed microdilution test for M. tuberculosis is a practical, rapid, quantitative, nonradiometric alternative for the determination of MICs in clinical mycobacteriology laboratories.

Antitubercular Agents↗
PubMed1999

[Digital recording in neurosurgery].

The purpose of this study is to examine the image quality of multi-media for digital recording of surgical procedure using an operating microscope in neurosurgery. For video recording, high vision recording, digital video recording and analogue VHS recording were used. For still pictures, an analogue camera with 35 mm silver halide film and a micro-digital camera were used. The quality of photographs taken with a microdigital camera was superior to the quality of those taken with the conventional 35 mm film camera. The micro-digital camera system is superior to the conventional 35 mm camera in neurosurgery in its quality and success rate. In video recording, high vision analogue recording was superior to any other media as far as its image quality is concerned although its practical convenience is limited and cost performance is not always good. On the other hand, digital video can record high quality images, including still pictures, with satisfactory quality to the neurosurgeon. These digital recording media are also space saving for storing the huge amount of data obtained during surgery and the cost-performance is superior to that of the conventional method. In the near future, most of surgical procedures are supposed to be expected using digital media.

Humans↗
PubMed1999

[Evaluation of a fully automated mycobacteria culture system, MB/BacT using a newly developed digestion-decontamination procedure, semi-alkaline protease-N-acetyl-L-cysteine-NaOH (SAP-NALC-NaOH) method].

A fully automated non-radiometric mycobacteria culture system, MB/BacT (Organon Teknika, Durham, NC, U.S.A.), was recently introduced in Japan and evaluated for its ability to detect mycobacteria in clinical sputum specimens. A previous study yielded nearly a 40% contamination ratio from sputa treated with the standard N-acetyl-L-cysteine (NALC)-NaOH method. This study employed a mucolytic agent (semi-alkaline protease; SAP) in which the sputa were processed twice for digestion followed by decontamination at twice the standard volume of NALC-NaOH. The concentrated sediments were resuspended in phosphate buffer (0.067 M, pH 6.8), and inoculated into the MB/BacT Process Bottles supplemented with antibiotics. The bottles were incubated at 37 degrees C and monitored for up to fifty-six days. Recovery of mycobacteria was compared in three different egg-based Ogawa media in addition to a non-selective Middlebrook 7H10 agar. A total of 1, 124 clinical sputum specimens have been evaluated. Of these, 464 were positive for growth of mycobacteria, of which 447 (96.3%) were positive by the MB/BacT. False-positive alarms due to break through contamination, mainly by Pseudomonas aeruginosa and Candida spp., were observed in twenty-one specimens (1.9%). The three Ogawa media could detect only 283 (60.5%) to 353 (75.4%) positives, and Middlebrook 7H10 agar only 424 (90.6%) positives. The time to detect positive cultures of Mycobacterium tuberculosis complex by the MB/BacT ranged from 2.2 days to 52.3 days, and 50% of positive cultures were detected within 16.7 days of incubation. It can be concluded that the combination of SAP-NALC-NaOH digestion-decontamination procedure and the MB/BacT is particularly useful for the isolation of mycobacteria and has a faster time to detect than conventional methods. MB/BacT is a suitable alternative method for the detection of mycobacteria in Japan, where the radiometric Bactec System is not available.

Acetylcysteine↗
PubMed1998

Similarity in moth-fly specific larvicidal activity between two serologically unrelated Bacillus thuringiensis strains.

Parasporal inclusions of a Bacillus thuringiensis isolate designated 92-KU-105-9 (H14/19) exhibited unusual larvicidal activity, specific for the moth-fly, Telmatoscopus albipunctatus (Diptera: Psychodidae), similar to that of a previously reported B. thuringiensis serovar leesis (H33) strain. The LC50 value of the purified inclusions was 4.92 micrograms ml-1 for the moth-fly larvae, while no mortality was shown in the mosquitoes Culex pipiens molestus and Anopheles stephensi, at protein concentrations up to 10 mg ml-1. Morphologically, the inclusion was a homogeneous globular body surrounded by an electron-dense, thick envelope. Multilamellar inner structure was evident between envelope membrane and inclusion matrix. SDS-PAGE revealed that the inclusions consist of five proteins with molecular masses of 72, 70, 68, 56 and 30 kDa. These proteins cross-reacted with the antibodies against inclusion proteins of the serovar leesis strain. High homologies existed in N-terminal amino acid sequences between the three major proteins (72, 70 and 68 kDa) and the two established protein classes, Cry4A and Cry10A.

Amino Acid Sequence↗
PubMed1998

Abnormality of alpha-adrenergic vascular response in patients with neurally mediated syncope.

Although diagnosis of neurally mediated syncope (NMS) using the head-up tilt (HUT) test has been established, the precise etiologic mechanism of NMS is still obscure. Previously, we reported the contribution of impaired alpha-adrenergic vascular response to syncope in patients with various arrhythmias. This study evaluates alpha-adrenergic vascular response in 21 NMS patients with syncope and a positive HUT test (80 degrees, 30 minutes, and low-dose isoproterenol, NMS group, mean age 31 +/- 14 years) and 21 control subjects (C group, 33 +/- 14 years) who had no evidence of syncope and no structural heart disease. After 30 minutes in a recumbent position, pharmacologic total autonomic blockade was attained using atropine and propranolol. Thereafter, increased systolic blood pressure with 0.4 microg/kg/min phenylephrine (designated as deltaBPphenyl) and decreased systolic blood pressure with 0.5 microg/kg/30 seconds of phentolamine (designated as deltaBPphent) were measured as indexes of alpha-adrenergic vascular sensitivity and activity, respectively. DeltaBPphenyl in the NMS group (70.0 +/- 37) was significantly less than that in C group (107 +/- 38, p <0.005). DeltaBPphent was significantly greater in the NMS group than in the C group (33.5 +/- 10 vs 21.0 +/- 14, p <0.005). Thus, decreased alpha-adrenergic vascular sensitivity and elevated alpha-adrenergic vascular tone were observed in patients with NMS. Although it is not known whether the mechanism causing NMS can be attributed to this abnormal alpha-adrenergic vascular response, the abnormality could at least contribute to augmenting the symptoms of NMS.

Adrenergic alpha-Agonists↗
PubMed1998

The different mobility of complementary strands depends on the proportion AC/GT.

The electrophoretic mobility of DNA fragments on denaturing polyacrylamide gel depends on various factors. One of these is the base composition of a single-stranded DNA (ssDNA). We confirmed that one strand and its complementary strand of polymerase chain reaction (PCR) products migrated with different mobilities in all alleles detected at 12 out of the 13 short tandem repeat (STR) loci studied. The mobility differences between complementary strands (MD) were also observed regardless of end-polishing with Pfu DNA polymerase. MD was therefore not influenced by additional nucleotides to each strand of the PCR products. We then analyzed the relation between MD and the base composition using one representative allele at each of the 13 loci. The results indicated that MD was affected by the adenine plus cytosine (AC) content in the ssDNA and was proportional to the values of the AC content divided by the guanine plus thymine (GT) content in the AC-rich strand (the proportion AC/GT). When the proportion AC/GT was well-balanced, MD decreased. The same tendency was observed even in the end-polished strands. In this study, the electrophoretic mobility of an ssDNA on denaturing polyacrylamide gels was shown to depend on the proportion AC/GT. Unless the same side of the PCR products is labelled in the context of a PCR-based STR typing, distinct alleles may be mistaken for identical ones because of the different mobility of complementary strands. Accordingly, the labelled strand should be described if only one strand of the PCR products is detected. When using an allelic ladder marker as a size standard, the labelled side should be unified between STR alleles and the allelic ladder alleles.

Adenine↗
PubMed1998

Ubc9p and the conjugation of SUMO-1 to RanGAP1 and RanBP2.

The yeast UBC9 gene encodes a protein with homology to the E2 ubiquitin-conjugating enzymes that mediate the attachment of ubiquitin to substrate proteins [1]. Depletion of Ubc9p arrests cells in G2 or early M phase and stabilizes B-type cyclins [1]. p18(Ubc9), the Xenopus homolog of Ubc9p, associates specifically with p88(RanGAP1) and p340(RanBP2) [2]. Ran-binding protein 2 (p340(RanBP2)) is a nuclear pore protein [3] [4], and p88(RanGAP1) is a modified form of RanGAP1, a GTPase-activating protein for the small GTPase Ran [2]. It has recently been shown that mammalian RanGAP1 can be conjugated with SUMO-1, a small ubiquitin-related modifier [5-7], and that SUMO-1 conjugation promotes RanGAP1's interaction with RanBP2 [2,5,6]. Here we show that p18(Ubc9) acts as an E2-like enzyme for SUMO-1 conjugation, but not for ubiquitin conjugation. This suggests that the SUMO-1 conjugation pathway is biochemically similar to the ubiquitin conjugation pathway but uses a distinct set of enzymes and regulatory mechanisms. We also show that p18(Ubc9) interacts specifically with the internal repeat domain of RanBP2, which is a substrate for SUMO-1 conjugation in Xenopus egg extracts.

Animals↗
PubMed1998

Unique appendages associated with spores of Bacillus cereus isolates.

Electron microscopic observations revealed the presence of a new type of large appendage on the spores of two Bacillus cereus strains isolated from phylloplanes. The appendages were thin and sword-like in shape, having the sizes of 1.5 to 2.8 microns in length and 0.03 to 0.6 micron in width. There were no core or sheath structures in these appendages. The number of appendages on a spore ranged from three to more than twenty, radiating from the swelling on one end of the exosporium. These appendages gave a unique octopus- or jellyfish-like feature to the spores.

Bacillus cereus↗