Biomedical subjects

K Saitou

Publications and source records attributed to K Saitou.

At least 19 recordsLinked to original sources

PubMed2001

Septic arthritis of a lumbar facet joint due to pyonex.

We present a case of septic arthritis of a lumbar facet joint with an associated epidural abscess. A 13-year-old boy was hospitalized with acute severe back pain and fever after pyonex was done. The infection was precisely localized with magnetic resonance imaging, bone and gallium scintigraphy. He responded to antibiotic therapy. We suppose that the infection was caused by pyonex because the blood cultures were negative, and the patient had an abrupt onset of severe pain and fever 24 h after the acupuncture.

Acupuncture Therapy↗

PubMed2001

Influence of contraction force and speed on muscle fiber conduction velocity during dynamic voluntary exercise.

Before using electromyographic (EMG) variables such as muscle fiber conduction velocity (MFCV) and the mean or median frequency (MDF) of an EMG power spectrum as indicators of muscular fatigue during dynamic exercises, it is necessary to determine the influence of a joint angle, contraction force and contraction speed on the EMG variables. If these factors affect the EMG variables, their influence must be removed or compensated for before discussing fatigue. The vastus lateralis of eight normal healthy male adults was studied. EMG signals during non-fatiguing dynamic knee extension exercises were detected with a three-bar active surface electrode array. EMG variables were calculated from the detected signals and compared with the angle of the knee joint, the extension torque and the extension speed. The extension torque was set at four levels with 10% intervals between 40 and 70% of the maximum voluntary contraction. The extension speed was set at five levels with 60 degrees /s intervals between 0 and 240 degrees /s. Because the joint angle unsystematically affected the MFCV, EMG variables at a given joint angle were extracted for comparison. The influence of the extension torque and speed on the extracted EMG variables was clarified with an ANOVA and a regression analysis. The statistical analyses showed that MFCV increased with the extension torque but did not depend on the extension speed. In contrast, MDF was independent of the extension torque but was dependent on the extension speed. MDF thus showed a behavior different from that of MFCV. It became clear that if MFCV is used as an indicator of muscular fatigue during dynamic exercises, it is at least necessary to extract MFCV at a predetermined joint angle and then remove the influence of extension torque on MFCV.

Action Potentials↗

PubMed2001

Intratubular calcification in a post-renal transplanted patient with secondary hyperparathyroidism.

In this article, we present a case in which marked intratubular calcification occurred in the transplanted kidney. The patient received living renal transplantation without control of severe secondary hyperparathyroidism, and the tacrolimus hydrate was used as an immunosuppressive agent, the adverse effects of which can induce intratubular calcification. Biopsy of the renal allograft revealed many intratubular calcifications in the cortex region of the specimen, although the histological grade was borderline for the Banff classification. The pathogenic causes of intratubular calcification were difficult to distinguish from the adverse effects of tacrolimus and the uncontrolled hyperparathyroidism.

Biopsy↗

PubMed2001

Senile plaques in an aged western lowland gorilla.

Senile plaques (SPs) were found in the cerebral cortex of a 44-year-old Western lowland gorilla (Gorilla gorilla gorilla). All the SPs were obtained as dense assemblies consisting of fibrous materials by silver impregnation, but were not detected by Congo red. More SPs were detected by immunostaining for amyloid beta protein (A beta) and a half of A beta-positive-SPs were also immunoreactive for apolipoprotein E. Moreover, all SPs were immunoreactive for A beta 42 and A beta 43, but not for A beta 40. SPs also did not contain A beta precursor protein-positive structures. These findings suggested that SPs in this case were diffuse plaques. To our knowledge, this is the first report of SPs in the gorilla.

Aging↗

PubMed2001

[Rupture of renal pelvis due to urolithiasis: report of two cases].

Two cases of renal pelvis rupture caused by urolithiasis are reported. The first case was in a 62-year-old male who had left flank pain. Urological examination including drip infusion pyelography (DIP) and abdominal computed tomography (CT) revealed a spontaneous rupture of the left renal pelvis. The rupture was assumed to have been caused by a small ureteral stone. The stone passed spontaneously, and the extravasation disappeared with conservative therapy. The second case was in a 84-year-old male who was admitted with high fever. Urological examination including DIP and abdominal CT showed a suspected rupture of the left renal pelvis due to a renal stone at the ureteropelvic junction. Percutaneous nephrostomy was performed and antegrade pyelography showed extravasation from the left renal pelvis. Extravasation disappeared on the 12th postoperative day. Extracorporeal shock wave lithotripsy was performed three times. The renal stone was completely discharged and the nephrostomy tube was removed successfully.

Aged↗

PubMed2000

Age and sex differences in the bone mineral density of the distal forearm based on health check-up data of 6343 Japanese.

Bone mineral density (BMD) predicts osteoporotic fractures. The incidence of osteoporotic fractures in Japan is lower than among Caucasians, but fewer data on the BMD of Asians have been reported. This study attempted to clarify the age and sex differences in the forearm BMD of healthy adult Japanese and to assess racial differences between Japanese and Caucasians. The subjects were 6343 healthy adult Japanese (5281 females, 1062 males) who underwent a health check-up at a health care service center between February 1995 and August 1999. Subjects' age ranged from 15 to 80 years. The BMD of the distal radius and ulna of the non dominant forearm was measured by dual-energy X-ray absorptiometry. Overall, the forearm BMD of men was greater than that of women in all age groups. Peak BMD was 0.484 g/cm2 in the 40-44 year age group of women and 0.590 g/cm2 in the 30-34 year age group of men. The forearm BMD of women under 50 years of age (the average age at menopause) increased slightly with age (2.0%/decade, p < 0.0001), but it did not among their male counterparts. After 50 years of age, BMD of the women decreased linearly (-1.6%/year, p < 0.0001) with age, the rate of decrease being 1.7-fold faster than in their male counterparts. Rates of gain and loss of forearm BMD differ between the sexes. In comparison with data previously reported, we did not find any evidence of racial differences in BMD as an explanation for the lower incidence of osteoporotic fractures in Japan.

Absorptiometry, Photon↗

PubMed2000

Effect of mometasone furoate by topical application on allergic rhinitis model in rats.

The effects of mometasone furoate on experimental allergic rhinitis in rats were studied in comparison with that of fluticasone propionate. Topical application of both drugs inhibited dose-dependently the increase of nasal symptoms (sneezing and nasal rubbing) after antigen challenge to the nasal cavity of actively sensitized rats. Mometasone furoate and fluticasone propionate at concentrations of 0.01 or 0.1% significantly inhibited both nasal rubbing and sneezing 1 h after topical application of both drugs. The relative potencies of mometasone furoate in nasal rubbing and sneezing compared to fluticasone propionate were 5.01 and 6.87, respectively. Mometasone furoate (0.02%) and fluticasone propionate (0.1%) significantly inhibited the increase of antigen-induced nasal rubbing even 6 h after topical application, indicating that both drugs have a long-lasting effect.

Administration, Topical↗

PubMed2000

[Assessment of most appropriate background subtraction method for quantification of 123I-metaiodobenzylguanidine (MIBG) myocardial uptake by comparing with plasma ANP and BNP].

BACKGROUND: Quantification of 123I-metaiodobenzylguanidine (MIBG) myocardial uptake is widely accepted as a useful tool for estimating the severity of congestive heart failure. However, most reliable method has not been determined yet because of the difficulty of background (BG) subtraction. In this study, the most appropriate BG subtraction method was evaluated as compared with plasma atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine (NEP) and left ventricular ejection fraction (LVEF). METHODS: Twenty-one patients with chronic heart failure were examined. After bolus injection of 123I-MIBG (111 MBq), dynamic anterior chest images were collected every second for 2 minutes. Planar anterior chest images were obtained 15 minutes (early image) and 4 hours later (delayed image) respectively. The parameters for quantification of 123I-MIBG myocardial uptake used in this study were heart to mediastinum ratio (H/M), myocardial washout rate and uptake ratio. Background was calculated using the region of interest (ROI) placed over a part of upper mediastinum, whole upper mediastinum, right lung and pericardial space respectively. The values of these parameters were calculated with and without BG subtraction and compared with plasma ANP, BNP and others. RESULTS: H/M did not correlate with ANP or BNP. Myocardial washout rate without BG subtraction showed significant correlation with ANP (p < 0.01) and BNP (p < 0.05). After BG subtraction employing ROI placed over the part of upper mediastinum and whole upper mediastinum, myocardial washout rate showed better correlation with BNP (p < 0.01). Myocardial uptake ratio did not showed any correlation with ANP or BNP without BG subtraction. However, myocardial uptake ratio showed significant correlation with BNP (p < 0.05) after subtraction of upper mediastinal BG. BG subtraction using ROI over right lung or pericardial area revealed poor results in both myocardial washout rate- and uptake ratio. CONCLUSION: BG subtraction using ROI over the upper mediastinum is likely to be suitable for quantitative analysis of 123I-MIBG myocardial scintigram.

3-Iodobenzylguanidine↗

PubMed2000

[Two cases of abdominal masses caused by foreign bodies which were preoperatively diagnosed as urachal abscess].

A 61-year-old man and a 59-year-old woman were referred to our hospital because of lower abdominal pain and discomfort, pollakisuria and a lower abdominal mass. In both patients, radiological studies and cystoscopy caused us to suspect a urachal abscess. We performed operations transperitoneally. In the male patient, fish bones were detected between the mass and ileum. A partial cystectomy was performed on the female patient, and the histological diagnosis was Sparganosis mansoni. In both cases, it was very difficult to make a correct diagnosis before the operations, but surgical treatment was successfully performed.

Abdominal Abscess↗

PubMed2000

The mechanism responsible for the drowsiness caused by first generation H1 antagonists on the EEG pattern.

The present study was performed to clarify the mechanism responsible for the drowsiness caused by first generation H1 antagonists according to electroencephalogram activity. All H1 antagonists used in the present study caused the EEG-recorded drowsiness pattern, i.e., increases in EEG power spectra of the delta and theta bands at the frontal cortex in rats. The potency of cyproheptadine was greater than those of diphenhydramine and promethazine, while that of pyrilamine was less than those of the other drugs examined. The increase in EEG power spectra in the delta band induced by H1 antagonists was antagonized by pretreatment with both histidine and physostigmine. The effect of pyrilamine was more potently antagonized by histidine and less potently antagonized by physostigmine as compared to diphenhydramine, promethazine and cyproheptadine. The increases in EEG power spectra induced by H1 antagonists were neither antagonized nor potentiated by 5-hydroxytryptophan. These results clearly indicate that the increases in EEG power spectra in the delta and theta bands at the frontal cortex in rats induced by first generation H1 antagonists are responsible for both histaminergic and cholinergic mechanisms.

5-Hydroxytryptophan↗

PubMed2000

[Comparison of detection pattern of HCC by ferumoxide-enhanced MRI and intratumoral blood flow pattern].

We compared the detection rate and pattern of ferumoxide-enhanced magnetic resonance imaging (Fe-MRI) with the intratumoral blood flow pattern determined by CT angiography (CTA) and CT portography (CTAP) in 124 nodes (34 cases) diagnosed as hepatocellular carcinoma (HCC) or borderline HCC, based on the clinical course. Sequences to obtain a T1-weighted images (T1W), proton density-weighted images (PDW), T2-weighted images (T2W), T2*-weighted images (T2*W) were used in Fe-MRI. In nodes shown to be hypervascular on CTA, the detection rate by Fe-MRI was 69.7%. In nodes shown to be avascular by CTAP, the detection rate by Fe-MRI was 67.3%. These rates were higher than with other flow patterns. In nodes showing high signal intensity (HSI) on any sequences, arterial blood flow was increased and portal blood flow decreased in comparison with nodes without high signal intensity. All nodes showing HSI, both on Fe-MRI T2W and T2*W, were hypervascular on CTA, and portal blood flow was absent on CTAP. Nodes showing HSI on both T2*W and T2W were considered to have greater arterial blood flow and decreased portal blood flow compared with nodes appearing as HSI on T2*W, but only as iso- or low signal intensity on T2W (Mann-Whitney U-test; p < 0.05).

Aged↗

PubMed2000

Innervation zones of the upper and lower limb muscles estimated by using multichannel surface EMG.

The distribution of innervation zones was investigated in 3 subjects for 17 muscles and 8 muscle groups in the upper and lower limb, by detecting bi-directional propagation of motor unit action potentials (MUAPs) with the multichannel surface electrode array. Clarification of the distribution of innervation zones depended on the ease in detecting the propagation of MUAPs and the actual scattering of innervation zones, which were closely related with muscle morphology with respect to the arrangements of muscle fibers. In muscles having fibers running parallel to each other, such as the biceps brachii, intrinsic hand muscles, vastus lateralis and medialis, tensor fasciae latae, peronei, soleus, tibialis anterior, and hypothenar muscles in the foot, it was relatively easy to detect the propagating MUAPs, and the innervation zones were distributed in a relatively narrow band around muscle belly. On the other hand, in muscles with a complicated structure including pinnation of muscle fibers, in-series muscle fibers and aponeurotic tissues, such as the deltoid, flexors and extensors in the forearm, rectus femoris, sartorius, hamstrings and gastrocnemius, it was more difficult to detect the propagating MUAPs and to identify the innervation zones, which were widely scattered or distributed in complex configurations. The distribution of the innervation zones clarified in the present study can be used to find the optimal location of electrodes in surface EMG recordings and of stimulus electrodes in the functional and therapeutic electrical stimulations. It may also be useful in motor point biopsy for diagnosis of neuromuscular diseases as well as in the botulinum toxin injection for the treatment of spasticity.

Action Potentials↗

PubMed1999

Depth and intensity of equivalent current dipoles estimated through an inverse analysis of surface electromyograms using the image method.

The depth and intensity of equivalent current dipoles that can create the surface potentials of active motor units in human skeletal muscles are estimated through an inverse analysis of surface electromyographic (EMG) potentials in an attempt to measure detailed muscular activity non-invasively. The inverse analysis is conducted by repetition of forward analyses. In the study, the image method is used for forward analysis, because it is the simplest potential calculation method for electric currents in a semi-infinite volume conductor. Using this method, surface EMG potentials are calculated for current sources assumed to be located in a muscle. An inverse analysis is then carried out by searching for the depth and intensity of such current sources that would minimise the sum of squares difference between measured and calculated surface EMG potentials. The inverse analysis is applied to surface EMG potentials measured from the biceps brachii of three healthy subjects. As a result, the individual current sources are estimated to be 2.7 +/- 1.6 mm deep and 0.5 +/- 0.9 nAm in intensity, whereas the total current intensity for individual motor units is 2.4 +/- 2.9 nAm.

Adult↗

PubMed1999

Slow wave sleep-inducing effects of first generation H1-antagonists.

The present study was performed to see if first-generation histamine H1-antagonists are useful sedative-hypnotic drugs. Increases in electroencephalogram (EEG) power spectra of the delta band (0-4 Hz) at the frontal cortex and theta band (4-8 Hz) at the hippocampus in rats were used as an indexes of sleep. The H1-antagonists used in this study resulted in a decrease in sleep latency and an increase in sleep duration (slow wave sleep). The rate of REM (rapid eye movement) sleep during slow wave sleep was decreased by H1-antagonists and brotizolam. The order of potency of H1-antagonists for the reduction in sleep latency (from greatest to least) was promethazine>chlorpheniramine>diphenhydramine and pyrilamine, and that for the increase in sleep duration was chlorpheniramine>promethazine>diphenhydramine and pyrilamine. Brotizolam was more potent than these H1-antagonists, with 14-18-fold and 4-14-fold greater effects on sleep latency and duration, respectively. These results clearly show that H1-antagonists are effective in mild to moderate insomnia as sedative-hypnotic drugs.

Animals↗

PubMed1999

[A case of sacral chordoma presenting as urinary retention].

A 71-year-old man was referred to our hospital complaining of urinary retention. He noticed a small mass on his buttocks about one year ago. Computed tomographic (CT) scan and magnetic resonance imaging (MRI) showed a large mass of 10 cm in diameter located in the retrovesical space. The mass extended to the surface of his buttocks and contained many calcified deposits, and was accompanied with a sacral bone fracture. Transdermic biopsy revealed the presence of sacral chordoma. Chordoma is a rare tumor, arising from remnants of the notochord and is locally progressive. Both tumor resection and diverting colostomy were performed at another hospital. In that operation his spinal cord was protected down to the second sacral level. Unfortunately after the operation, the patient suffered total urinary incontinence. At 15 months after surgical treatment, the patient presented with lung and bone metastases, and at 2 years after his initial operation, he had local recurrence.

Aged↗

PubMed1999

[Assumption of the area supplying Okayama Prefecture with Cryptomeria japonica and Cupressaceae airborne pollen, and of their scattering routes].

It is very important to predict and disseminate information about the total pollen counts of both Cryptomeria japonica and Cupressaceae for patients with pollinosis. In Okayama Prefecture, we have reported that the pollen counts of both Cryptomeria japonica and Cupressaceae are influenced by the meteorological conditions in the previous July. We predicted the area supplying Okayama Prefecture with Cryptomeria japonica and Cupressaceae pollen, and also the route of airborne pollen from the meteorological conditions and a topographical map of Okayama and four neighboring prefectures. It was found that Cryptomeria japonica and Cupressaceae pollen counts at the four observation sites correlated very well with the meteorological conditions at Tsuyama weather station in Okayama prefecture. Therefore, we considered that the areas supplying Okayama prefecture with Cryptomeria japonica and Cupressaceae pollen were the central northern areas including Tsuyama, 85.7% of whose plantation areas contained Cryptomeria japonica and Chamaecyparis obtusa, and that their pollen was carried along the routes of three major rivers, R. Takahashi, R. Asahi and R. Yoshii.

Air Pollutants↗

PubMed1998

Structure-cytotoxic activity relationship for the toad poison bufadienolides.

The toad poison bufadienolides including natural and derivatized compounds were tested for their cytotoxic effects on primary liver carcinoma cells PLC/PRF/5 and their structure-cytotoxic activity relationships were studied. For this study, a ligand-binding model was developed by using a pharmacophore mapping program, Distance Comparisons (DISCO). The structural features that are common to the 3D structures of active bufadienolides were identified to provide approach to a 3D QSAR method by using Comparative Molecular Field Analysis (CoMFA) study and to correlate the steric and electrostatic fields of the molecules to their activities. A valuable model which enables prediction of their activities was obtained from the CoMFA analysis, which may be employed for the drug designs of new bufadienolide analogues.

Antineoplastic Agents↗

PubMed1998

Effects of ethanol, acetoin and 2,3-butanediol on EEG power spectra in conscious rats.

Effects of ethanol, acetoin and 2,3-butanediol on the central nervous system (CNS) were investigated by using the analysis of EEG (electroencephalogram) spectral powers recorded at the frontal cortex in rats. High doses of ethanol were required for exhibiting an increase of EEG spectral powers in the delta (0-4 Hz) and theta (4-8 Hz) waves when it was given either orally or intravenously. On the other hand, when ethanol was injected intracerebroventricularly, the drug caused a potent increasing effect of EEG spectral powers. Both acetoin and 2,3-butanediol were found to increase in EEG spectral powers by oral and intravenous administrations at relatively low doses. In addition, acetoin and 2,3-butanediol were more effective than ethanol in increasing EEG spectral powers in the delta and theta bands after intracerebroventricular administration. From these findings it can be concluded that both acetoin and 2,3-butanediol have a potent CNS depressant effect.

Acetoin↗