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Biomedical subjects

S Suda

Publications and source records attributed to S Suda.

At least 37 records · Page 2Linked to original sources

Phylogenetic relationships between toxic and non-toxic strains of the genus Microcystis based on 16S to 23S internal transcribed spacer sequence.

16S to 23S ribosomal DNA internal transcribed spacer sequences of 47 strains of the genus Microcystis were determined. Derived maximum likelihood and DNA distance trees indicated that Microcystis can be divided into three clusters. The first cluster included toxic and non-toxic strains, the second only toxic ones, and the third only non-toxic ones. The tree topologies were not necessarily correlated with morphospecies distinction or phycobilin pigment composition, and one genotype may have more than one morphotype. Phylogenetic analysis based on intergenic spacer sequences was thought to be effective for understanding relationships among closely related species and strains.

Base Sequence↗

Induction of urethral closure and inhibition of bladder contraction by continuous magnetic stimulation.

Magnetic stimulation has been considered to be a technique for stimulating nervous system noninvasively and it has been used for experimental and clinical testings on the central and peripheral nervous systems. However, commercially available magnetic stimulators can only discharge single pulses for less than several minutes because the coil soon overheats. We newly devised a continuous magnetic stimulator assuring long-time stimulation, and this study was designed to confirm whether continuous magnetic stimulation would result in urethral closure and inhibition of bladder contraction in anesthetized canine models. Twelve female beagle dogs, weighing 9 to 12 kg, were anesthetized with a mixture of alpha-chloralose and urethane. In six beagles, a 4 F microtip transducer was inserted transurethrally, and maximum intraurethral pressure was monitored. In the remaining six animals, urethra was ligated at the bladder neck and a 4 F double lumen catheter was inserted from the dome of the bladder to infuse physiological saline, monitoring iso-volumetric rhythmic bladder contraction. The stimulating coil, of which temperature was kept at 20-25 degrees C by the built-in cooling system, was placed on the ishio-rectal fossa to stimulate the pudendal nerve at 10 Hz. The intraurethral pressure increased by 69.1 +/- 27.8 cm H(2)O, and iso-volumetric rhythmic bladder contraction was inhibited during the stimulation with 80% (240 Joule) of maximum output. In conclusion, continuous magnetic stimulator was found effective for urethral closure and inhibition of bladder contraction. Neurourol. Urodynam. 18:505-510, 1999.

Animals↗

Effect of functional continuous magnetic stimulation on urethral closure in healthy volunteers.

OBJECTIVES: To study urodynamically the effect of functional continuous magnetic stimulation on urethral closure in normal volunteers. METHODS: Ten volunteers (6 men and 4 women, 20 to 29 years old, mean age 24.5) were recruited for the study. Seven subjects were assigned to an active group and 3 to a sham group. An 8F transducer was inserted transurethrally, and the urethral pressure profile was monitored. Then the catheter was fixed so that the transducer could be positioned at the portion at which the highest pressure was recorded (maximum intraurethral pressure). In the active group, the stimulating intensity was gradually increased up to the tolerable limit. A 15-minute single session of stimulation was carried out at 20 Hz in an intermittent manner with 1-minute-on/30-second-off cycles. After stimulation, the urethral pressure profile was repeated. RESULTS: In the active group, the greatest pressure difference between the on and off phases of the maximum intraurethral pressure was 62.4+/-37.6 cm H2O at 35% to 55% of maximum output (46 to 113 J). In the urethral pressure profile, the maximum urethral closure pressure increased significantly after stimulation (P = 0.0280). In the sham group, no changes in these parameters were noted. All subjects tolerated the functional continuous magnetic stimulation well, and none experienced any adverse effect. CONCLUSIONS: Functional continuous magnetic stimulation safely and significantly increased maximum intraurethral pressure during stimulation and maximum urethral closure pressure after stimulation.

Adult↗

A multiparametric analysis of occlusal and periodontal jaw reflex characteristics in adult skeletal mandibular protrusion before and after orthognathic surgery.

Periodontal jaw reflex, duration of percussion sounds, tooth mobility, and time-moment analysis of occlusal contacts by the T-scan system were recorded in seven pre-orthognathic surgery patients and six post-orthognathic surgery patients over a 2-year period. The results showed that: (i) reflex response to the pressure applied to the upper right central incisor in the lingolabial direction varied, depending on the background jaw-clenching force (BCF) of the same-sided first molar. The BCF level required to elicit excitatory reflexes was only 0 kgf, and inhibitory reflexes were clearly elicited with a BCF of 1 kgf and beyond before orthognathic surgery. After orthognathic surgery BCF levels required to elicit excitatory reflexes were 0-4 kgf, and inhibitory reflexes were elicited with a BCF of 6 kgf and above; (ii) duration of percussion sounds determined via an occlusal sound analyser decreased in both the upper right central incisor and upper right first molar while tooth mobility measured by 'Periotest(R)' increased in the upper right central incisor, but did not change in the same-sided first molar after orthognathic surgery; (iii) the time moments of occlusal contacts were symmetrical toward the midsagittal axis of the occlusal plane after orthognathic surgery. The centre of the anterioposterior occlusal contacts did not differ between pre- and post-orthognathic surgery groups.

Adolescent↗

[Treatment of solid tumor by a direct electric current].

This is a case report of a 37-year-old Japanese married female with laryngeal sarcoma, treated by direct electric current so as to obtain remission for more than 4 years without signs of recurrence. Due to her hoarseness and laryngeal numb feeling she underwent a laryngeal examination including a biopsy, resulting in a diagnosis of sarcoma. She refused a total laryngectomy and was given Cobalt treatment of 40 Grey. In the following several months, no improvement was observed, objectively or subjectively. In Nagoya University Hospital the patient then received direct electric current therapy of 36 Coulombs through two platinum electrodes inserted into the tumor under a CT guide, pericutaneously. Two months later, as the hoarseness remained in spite of some improvement, she underwent another session of direct electric current therapy of 14.4 Coulombs through the platinum electrodes by bronchoscope-guided direct insertion. Her hoarseness soon disappeared thereafter and there was a regression of the tumor in 6 months. She did well thereafter without any signs of recurrence for 4 years. Clinical treatment of solid tumors with electric treatment with direct electric current has been done in more than 8,000 cases with CR in 25% of all cases and PR in 50%. Its mechanism, however, remains unclear. In our experimental animal studies, apoptosis was observed. It is considered that this electric therapy using direct electric current will be recognized as one method to treat solid tumors.

Adult↗

Development of a non-invasive treatment system for urinary incontinence using a functional continuous magnetic stimulator (FCMS).

A system composed of a functional continuous magnetic stimulator (FCMS) and a saddle-type coil has been developed for non-invasive treatment of urinary incontinence, especially stress incontinence and urge incontinence. The FCMS conditions were as follows: 2 kW maximum electrical power consumption, 800 V maximum capacitor voltage, 720 microseconds pulsewidth (180 microseconds rise time), and 5-30 Hz frequency. A frequency between 5 and 10 Hz is used to treat urge incontinence and a frequency between 25 Hz and 30 Hz is used to treat stress incontinence. The coil (120 mm long, 90 mm wide and 50 mm thick) fits the most suitable region for this treatment, the region from the anus to the perineum. The coil is cooled to maintain a coil temperature between 20 and 25 degrees C so that it can be used efficiently and safely. In experiments with anaesthetised dogs, it was confirmed that the urethral pressure increased when the circumference of the perineum received continuous magnetic stimulation of 720 microseconds pulsewidth (180 microseconds rise time), 10 Hz frequency and about 520 V capacitor voltage. This result suggests that magnetic stimulation can be effective as a urinary incontinence therapy.

Animals↗

Transcriptional and translational regulation of phosphodiesterase type IV isozymes in rat brain by electroconvulsive seizure and antidepressant drug treatment.

We examined the influence of electroconvulsive seizure (ECS) and imipramine (IMI) treatment on the transcription and translation of cyclic nucleotide phosphodiesterase type IV (PDE IV) isozymes in the rat brain. Our in situ hybridization studies revealed an increase of PDE IV-B mRNA level in various brain regions after acute ECS. However, the increase of PDE IV activity was produced not by acute but by chronic ECS treatment in the frontal cortex. Increased PDE IV-B mRNA expression in frontal but not in hippocampal subfields was induced also after chronic ECS treatment. Although an increase in PDE IV-A mRNA expression of the dentate gyrus in the hippocampus was observed, no change of PDE IV activity was produced in the hippocampus by acute or chronic ECS treatment. These results suggest that the repeated increases of PDE IV-B mRNA expression are attributable to the increase of PDE IV translation. Increased PDE IV-B transcription and PDE IV translation in the frontal cortex were also produced after chronic IMI treatment. This is the first report demonstrating an expressional regulation of Drosophila melanogaster dunce (dnc) gene homologue PDE IV isozymes in the brain. Although no pathophysiological conditions with reduced PDE IV activity in the nervous system are known except for a learning deficit in the mutant fly dnc-, our results suggest possible treatments to cope with reduced PDE IV activity.

3',5'-Cyclic-AMP Phosphodiesterases↗

[A case of ABO blood group incompatibility treated by exchange transfusion].

A patient with ABO blood group incompatibility who was treated by exchange transfusion is reported. A 63-year-old woman with blood group B type Rh (+) was accidentally transfused approximately 120 ml of A type Rh (+) packed red cells. She developed shock state, complaining chilliness, trepidation, nausea and vomiting just after the atypical blood transfusion. Fortunately, we could save her life without any complication by doing exchange transfusion in addition to anti-shock therapy and anticoagulant therapy preventing disseminated intravascular coagulation. The exchange transfusion was performed while monitoring central venous pressure. The total withdrawn blood reached 4300 ml, and 18 units of B type Rh (+) packed red cells, 10 units of AB type Rh (+) fresh frozen plasmas, 1250 ml of plasma protein fractions and 1750 ml of plasma expanders were infused with crystalloid fluid therapy. Although the amount of atypical blood transfusion to her was relatively small, it is considered that the exchange blood transfusion which seems to be only the fundamental therapy against atypical blood transfusion, took effect in saving her life without any complication.

ABO Blood-Group System↗

A non-MHC locus essential for autoimmune type I diabetes in the Komeda Diabetes-Prone rat.

The Long-Evans Tokushima Lean (LETL) rat, characterized by rapid onset of insulin-dependent (type I) diabetes mellitus (IDDM), no sex difference in the incidence of IDDM, autoimmune destruction of pancreatic beta cells, and no significant T cell lymphopenia, is a desirable animal model for human IDDM. We have established a diabetes-prone substrain of the LETL rat, named Komeda Diabetes-Prone (KDP) rat, showing a 100% development of moderate to severe insulitis within 220 d of age. The cumulative frequency of IDDM was 70% at 120 d of age, and reached 82% within 220 d of age. Here, we performed the first genome-wide scan for non-MHC IDDM susceptibility genes in this strain. The analysis of three crosses has led to the revelation of a major IDDM susceptibility gene, termed Iddm/kdp1, on rat chromosome (Chr) 11. Homozygosity for the KDP allele at this locus is shown to be essential for the development of moderate to severe insulitis and the onset of IDDM. Comparative mapping suggests that the homologues of Iddm/ kdp1 are located on human Chr 3 and mouse Chr 16 and would therefore be different from previously reported IDDM susceptibility genes.

Animals↗

A multiparametric analysis of occlusal and periodontal jaw reflex characteristics in young adults with normal occlusion.

Periodontal jaw reflex, duration of percussion sounds, tooth mobility, and time-moment analysis of occlusal contacts by the T-scan system was recorded in nine periodontally healthy volunteers. The results showed that (i) reflex responses to the pressure applied to the uppercentageral incisors in the lingolabial direction varied, depending on the background jaw-clenching force (BCF) of the same-sided first molars. The BCF levels to elicit excitatory reflexes were 6-8 Kgf, and inhibitory reflexes were clearly elicited with a BCF of 10 Kgf and beyond. (ii) Duration of percussion sounds via an occlusal sound analyser (4.73-4.84 mS: upper first molars, 4.89-5.00 mS: uppercentageral incisors) and tooth mobility using a 'Periotest' (3.3-3.5: upper first molars, 5.5-5.6: uppercentageral incisors) showed a normal value. (iii) The time moments of occlusal contacts were symmetrical toward the midsagittal axis of the occlusal plane. The centre of the anteroposterior occlusal contacts was located in the first molar regions.

Adult↗

Positive correlations between cerebral protein synthesis rates and deep sleep in Macaca mulatta.

Local rates of cerebral protein synthesis (ICPSleu) were determined with the autoradiographic L-[1-14C]leucine method in seven awake and seven asleep, adult rhesus monkeys conditioned to sleep in a restraining chair in a darkened, ventilated chamber while EEG, EOG, and EMG were monitored. Prior to the period of measurement all animals slept for 1-4 h. Controls were awakened after at least one period of rapid-eye-movement (REM) sleep. Experimental animals were allowed to remain asleep, and they exhibited non-REM sleep for 71-99% of the experimental period. Statistically significant differences in ICPSleu between control and experimental animals were found in four of the 57 regions of brain examined, but these effects may have occurred by chance. In the sleeping animals, however, correlations between ICPSleu and percent time in deep sleep were positive in all regions and were statistically significant (P < or = 0.05) in 35 of the regions. When time in deep sleep was weighted for the integrated specific activity of leucine in grey matter, positive correlations were statistically significant (P < or = 0.05) in 18 regions in the experimental animals. These results suggest that rates of protein synthesis are increased in many regions of the brain during deep sleep compared with light sleep.

Animals↗

[Serum levels of tumor necrosis factor alpha and soluble tumor necrosis factor-receptor I in asthmatic patients and patients with chronic respiratory tract infection].

In order to investigate the role of tumor necrosis factor alpha (TNF-alpha) in bronchial asthma or chronic respiratory infection, we measured serum levels of TNF-alpha and serum soluble tumor necrosis factor-receptor I (sTNF-RI) in asthmatic patients (n = 11) and patients (n = 10) with chronic respiratory infection by Pseudomonas aeruginosa. We also measured serum levels of eosinophil cationic protein (ECP) in the asthmatic patients. The serum levels of TNF-alpha in the asthmatic patients, patients with chronic respiratory tract infection and control group were 2.864 +/- 0.719 g/ml, 2.564-1.384 pg/ml and 0.681 +/- 0.453 pg/ml respectively. The levels of the former two groups were higher than those of the control group (p < 0.05). The serum levels of sTNF-RI in the asthmatic patients, the patients with chronic respiratory tract infection, and the control group was 758 +/- 268 pg/ml, 999 +/- 242 pg/ml and 909 +/- 268 pg/ml respectively. The levels of the former two groups did not differ significantly from those of the control group. There were significant correlations between TNF-alpha and sTNF-RI in the control group and in the patients with chronic respiratory tract infection, but there was no significant correlation in the asthmatic patients. In the asthmatic patients. TNF-alpha/s TNF-RI correlated with %best of PEF (r = 0.691, n = 9, p 0.0373). The serum levels of ECP correlated significantly with TNF-alpha, but not with sTNF-RI in the asthmatic patients. It is suggested that TNF-alpha plays a significant role in the pathogenesis of bronchial asthma and chronic respiratory tract infection as a factor causing inflammation and that the increase of TNF-alpha/sTNF-RI reflects the activation of eosinophil functions in an asthmatic attack.

Adult↗

Differences in motor control in the bronchus and extrathoracic trachea.

The motor control of the bronchus and extrathoracic trachea was evaluated by continuously measuring bronchial diameter and tracheal muscle tension as well as phrenic nerve activity in decerebrated, paralyzed, artificially ventilated dogs. Spontaneous rhythmic changes in bronchial diameter and tracheal muscle tension occurred in phase with phrenic burst during mechanical ventilation and during apnea induced by disconnecting the ventilator. There was a small but consistent difference in the timing of their rhythmic activities; bronchial constriction started at mid-inspiration, whereas tracheal contraction began just prior to the end of inspiration. Both were active in the post-inspiratory phase. Both hypercapnia and apnea caused an enhanced rhythmic constriction of the bronchus, while evoking a tonic contraction of the trachea. Intermittent electric stimulation of the efferent vagus nerves revealed that repetitive stimulation with a short intermission was necessary to evoke a sustained constriction of the bronchus, and that the bronchus could maintain the sustained constriction only transiently. These results indicate that the motor control of the bronchus and extrathoracic trachea are distinct. The central nervous system may contribute to the difference in timing of the contraction between tracheal and bronchial smooth muscle. However, the difference in response to electric stimulation of the nervus vagus may be attributed to the peripheral neuromuscular system.

Animals↗

Effect of occlusion on human skin.

In order to investigate the effect of occlusion on the skin, the flexor sides of both upper arms were covered with column-shaped with column-shaped closed chambers, 30 mm in outer diameter, 20 mm in inner diameter, and 5 mm in height, which were made of polyethylene foam. The tops of the chambers were sealed by plastic films with various levels of water vapor permeability to control moisture in each chamber. The raised chamber walls prevented direct contact between the skin and the plastic film. After 24 h of application, morphological changes of the skin surface were observed microscopically by the nitrocellulose-replica method. Although no visual alterations were found on all areas of occluded skin, microscopic evaluation showed that simple occlusion by films induced an increase in the number of deepened skin furrows on the skin surface. this increase was associated with lower water vapor permeability of the films, as well as with higher values of both temperature and humidity of the test day. Thus, since conditions which facilitate perspiration from the skin tend to cause skin irritation, prolonged exposure of the skin to sweat by simple occlusion may act as a primary skin irritant.

Adult↗

In vivo administration of IL-1 beta accelerates silk ligature-induced alveolar bone resorption in rats.

The effects of recombinant human interleukin-1 beta (rhIL-1 beta) on alveolar bone resorptive activity in rats were examined. Continuous administration of rhIL-1 beta or phosphate-buffered saline (PBS) was given via osmotic pumps for 3, 7 and 14 days to rats with silk ligatures around second maxillary molars. Other animals without ligatures received insertion of pumps containing rhIL-1 beta or remained untreated. Sections were subject to three different stains:--hematoxylin and eosin (H-E) for histology, acid phosphatase (ACPase) activity for osteoclast detection, and immunohistochemistry using anti-rat monocyte/macrophage monoclonal antibody (ED 1). In addition, body weight, plasma calcium and phosphorus levels were monitored. The mean body weight of rats receiving rhIL-1 beta was significantly lower (P < 0.05 to P < 0.01) compared with untreated rats throughout the experimental period. On Day 7, plasma calcium and phosphorus levels were significantly lower in rats receiving rhIL-1 beta than in rats receiving PBS only (P < 0.05). Sections revealed a moderate inflammatory cell infiltrate reaching near the alveolar crest in both groups with ligatures on Day 3. Only rats receiving rhIL-1 beta exhibited enhancement of inflammatory cell invasion on Days 7 and 14. In rats receiving rhIL-1 beta with ligatures, numerous resorption lacunae containing ACPase-positive multinucleated giant cells (MNGCs), coinciding with ED1-positive cells, were located on the mesial side of the septum where extensive bone resorption had occurred throughout the experimental period. In animals receiving rhIL-1 beta without ligatures, compared with untreated rats, increased ACPase-positive cells were observed on the mesial side of the septum on Day 3. In animals receiving PBS only, a few ACPase-positive cells were observed confined to the mesial regions where slight bone resorption occurred on Days 7 and 14. These results indicate that the administration of rhIL-1 beta accelerated alveolar bone destruction in ligature-induced periodontal tissue inflammation over a two-week period.

Acid Phosphatase↗

[Nuclear magnetic resonance relaxation times for human lung cancer and lung tissues].

We investigated the nuclear magnetic resonance (NMR) relaxation times, T1 and T2, for lung cancer tissue, and other samples of lung tissue obtained from surgical specimens. The samples were nine squamous cell carcinoma, five necrotic squamous cell carcinoma, 15 adenocarcinoma, two benign mesothelioma, and 13 fibrotic lungs. The relaxation times were measured with a 90 MHz NMR spectrometer and the results were correlated with histological changes. The values of T1 and T2 for squamous cell carcinoma and mesothelioma were significantly longer than those of adenocarcinoma and fibrotic lung tissue. There were no significant differences in values of T1 and T2 between adenocarcinoma and lung tissue. The values of T1 and T2 for benign mesothelioma were similar to those of squamous cell carcinoma, which suggested that increases in T1 and T2 are not specific to malignant tissues.

Adenocarcinoma↗

Effects of physostigmine on local cerebral glucose utilization in the central components of the rat visual system.

The effects of intravenous administration of physostigmine at doses of 0.03, 0.095, or 0.3 mg/kg on local cerebral glucose utilization (LCGU) were determined in 3 structures of the visual system of the rat brain by means of the quantitative 2-[14C]deoxyglucose method. LCGU was increased in the superior colliculus (superficial gray layer), but unchanged in the visual cortex and the lateral geniculate body. To determine whether the observed effect of physostigmine on the superior colliculus depended on input from the retina, the highest dose of physostigmine was administered to rats which had previously been enucleated bilaterally. Enucleation decreased LCGU in the superior colliculus of the animals not treated with physostigmine and blocked the effect of physostigmine on LCGU. The effect of physostigmine in the superior colliculus appears, therefore, to depend on input from the retina.

Animals↗