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Biomedical subjects

S Saeki

Publications and source records attributed to S Saeki.

At least 19 recordsLinked to original sources

Clinical application of carbon fibre reinforced plastic leg orthosis for polio survivors and its advantages and disadvantages.

A prospective study was carried out on the clinical application and features of a carbon fibre reinforced plastic leg orthosis (carbon orthosis) for polio survivors. The subjects comprised 9 polio survivors, and 11 carbon knee-ankle-foot orthoses (KAFOs) were prescribed, fabricated, and checked out at the authors' post-polio clinic. Walking was classified based on the functional ambulatory category, and the features of walking with a carbon orthosis were self-evaluated by using a visual analogue scale. The period from modelling a cast to completion was 55 +/- 25 days; the weight of a carbon KAFO was 27.8% lighter than that of the ordinary KAFO; the standard carbon KAFO was 50% more expensive than the ordinary KAFO. The carbon KAFO remained undamaged for at least 2 years. It improved the scores in the functional ambulation categories, but there was no difference between walking with an ordinary and with a carbon KAFO. The self-evaluation of walking with a carbon KAFO revealed that the subjects using a carbon KAFO were satisfied with their carbon KAFO. The carbon KAFO is lightweight, durable, slim and smart, and is positively indicated for polio survivors.

Braces↗

Normalization of acceleromyographic train-of-four ratio by baseline value for detecting residual neuromuscular block.

BACKGROUND: This study was designed to recognize the importance of normalizing postoperative acceleromyographic train-of-four (TOF) ratio by the baseline TOF value obtained before neuromuscular block for ensuring adequate recovery of neuromuscular function. METHODS: In 120 patients, TOF responses of the adductor pollicis to the ulnar nerve stimulation were monitored by acceleromyography (AMG) during anaesthesia using propofol, fentanyl and nitrous oxide. Control TOF stimuli were administered for 30 min. A TOF ratio measured at the end of control stimulation was regarded as a baseline value. Neuromuscular block was induced with vecuronium 0.1 mg kg(-1) and was allowed to recover spontaneously. Duration to a TOF ratio of 0.9 as calculated by AMG (DUR-raw 0.9) was compared with that of 0.9 as corrected by the baseline TOF ratio (i.e. 0.9 x baseline TOF ratio; DUR-real 0.9). RESULTS: Baseline TOF ratios ranged from 0.95 to 1.47. The average TOF ratios observed every 5 min were constant throughout control stimulation from at time zero mean (SD) [range]; 1.11 (0.09) [0.94-1.42] to at 30 min 1.13 (0.11) [0.95-1.47]. The DUR-real 0.9 was 91.0 (18.0) [51.3-131.0] min and was significantly longer than the DUR-raw 0.9 (81.2 (16.3) [41.3-123.0] min). CONCLUSIONS: Baseline TOF ratios measured by AMG are usually more than 1.0 and vary widely among patients. Therefore a TOF ratio of 0.9 displayed postoperatively on AMG does not always represent adequate recovery of neuromuscular function and should be normalized by baseline value to reliably detect residual paralysis.

Acceleration↗

Effects of various anti-asthmatic agents on mite allergen-pulsed murine bone marrow-derived dendritic cells.

BACKGROUND: Dendritic cells (DCs) play an important role in the immune response and are critically involved in asthma. beta2-agonists could potentially exacerbate type 2 T helper (Th2) cell-mediated immune response. OBJECTIVES: To determine the effects of various anti-asthmatic agents on DCs function both in vitro and in vivo. METHODS: Murine bone marrow-derived DCs were pulsed with mite allergen in the presence of pranlukast, salbutamol, salmeterol or fluticasone. These DCs were then inoculated intranasally into naïve mice to induce allergic airway inflammation in vivo. RESULTS: Pranlukast reduced IL-10 and increased IL-12, while fluticasone reduced both IL-10 and IL-12 production by mite allergen-pulsed DCs. Allergic airway inflammation in pranlukast- and fluticasone-treated and mite allergen pulsed DCs-harbouring mice was attenuated and such response was associated with inhibition of Th2 response in the airway. Salbutamol did not alter cytokine production, while salmeterol reduced IL-12 production by mite allergen-pulsed DCs. Lung pathology in beta2-agonist-harbouring mice was comparable with those of mite allergen-pulsed DCs-harbouring mice. CONCLUSIONS: Our results indicate that leukotriene receptor antagonists and corticosteroids inhibit DCs-induced Th2 skewed immune response, and that short- and long-acting beta2-agonists do not modify DCs-induced allergic airway inflammation.

Albuterol↗

Effects of primary and secondary low-grade respiratory syncytial virus infections in a murine model of asthma.

BACKGROUND: Respiratory syncytial virus (RSV) infection is known to develop and exacerbate asthma in young children. In adult, RSV causes recurrent but asymptomatic infections. However, the impact of asymptomatic RSV infection on adult asthma is yet to be determined. The present study is designed to determine the effects of primary and secondary low-grade RSV infections on allergic airway inflammation in a murine model of allergic asthma. METHODS: A low-grade RSV (2 x 10(3) plaque-forming units/mouse) was inoculated, and this caused neither pulmonary inflammation nor symptoms but induced significant IFN-gamma production in thoracic lymph nodes. To investigate interaction between low-grade virus and Dermatophagoides farinae (Df), airway hyper-responsiveness, lung inflammation and cytokine production from thoracic lymph nodes were compared after primary and secondary low-grade RSV infections in four groups of mice; control, Df allergen-sensitized, RSV-infected and Df-sensitized RSV-infected mice. A direct comparison between low- and high-grade RSV infections was also performed in primary infection. To investigate the role of IL-5 during secondary RSV infection, anti-IL-5 monoclonal antibody (anti-IL-5 mAb) was injected in mice and similar parameters were compared in four groups of mice. RESULTS: Primary high-grade RSV infection increased allergen-induced airway inflammation, while primary low-grade RSV infection attenuated allergen-induced airway inflammation concomitant with significant IFN-gamma production in lung-draining lymph nodes. In marked contrast, secondary low-grade RSV infection increased both IFN-gamma and IL-5 production, resulting in exacerbation of allergen-induced airway inflammation. Anti-IL-5 mAb treatment in secondary low-grade RSV infection and Df allergen-sensitized mice attenuated virus and allergen-induced airway inflammation. CONCLUSIONS: Low-grade RSV infection per se does not cause pulmonary inflammation, whereas it induces a significant immunological response in the allergen-sensitized host. These results indicate that subclinical and recurrent RSV infection may play an important role in exacerbation and maintenance of asthma in adults, wherein IL-5 is critically involved.

Animals↗

Bronchial hyperresponsiveness and airway inflammation in adolescents with asymptomatic childhood asthma.

BACKGROUND: About 70% of childhood asthmatics become free of asthma-related symptoms during adolescence. Little is known about bronchial hyperresponsiveness (BHR) and airway inflammation in young adults with "outgrown" childhood asthma. METHODS: We studied 61 nonsmoking medical students (18 intermittent mild asthmatics, 23 students with outgrown childhood asthma but free of asthma-related symptoms for 10 years (asymptomatic asthmatics) and 20 healthy students). BHR and lung function were measured, and induced sputum samples analyzed for eosinophil count, eosinophilic cationic protein (ECP), granulocyte-macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha). RESULTS: BHR was still present in most asymptomatic asthmatics, but it was milder compared with healthy students. Only three subjects with previous asthma had no BHR and no signs of airway inflammation. Percentages of eosinophil, and ECP, TNF-alpha and GM-CSF concentrations in induced sputum of mild asthmatics and asymptomatic asthma groups were higher than in the healthy group. In asymptomatic asthmatics group, the duration of asthma, sputum eosinophil percentage, and the level of TNF-alpha in sputum correlated significantly with BHR. CONCLUSIONS: Only a few subjects with longstanding asymptomatic asthma could be considered as cured; most asymptomatic asthmatics continued to exhibit BHR and signs of airway inflammation. The outcome of childhood asthma and BHR was associated with the degree of airway inflammation and the duration of childhood asthma.

Adolescent↗

Complete, long-lasting protection against lethal infectious bursal disease virus challenge by a single vaccination with an avian herpesvirus vector expressing VP2 antigens.

Marek's disease herpesvirus is a vaccine vector of great promise for chickens; however, complete protection against foreign infectious diseases has not been achieved. In this study, two herpesvirus of turkey recombinants (rHVTs) expressing large amounts of infectious bursal disease virus (IBDV) VP2 antigen under the control of a human cytomegalovirus (CMV) promoter or CMV/beta-actin chimera promoter (Pec promoter) (rHVT-cmvVP2 and rHVT-pecVP2) were constructed. rHVT-pecVP2, which expressed the VP2 antigen approximately four times more than did rHVT-cmvVP2 in vitro, induced complete protection against a lethal IBDV challenge in chickens, whereas rHVT-cmvVP2 induced 58% protection. All of the chickens vaccinated with rHVT-pecVP2 had a protective level of antibodies to the VP2 antigen at the time of challenge, whereas only 42 and 67% of chickens vaccinated with rHVT-cmvVP2 or the conventional live IBDV vaccine, respectively, had the antibodies. The antibody level of chickens vaccinated with rHVT-pecVP2 increased for 16 weeks, and the peak antibody level persisted throughout the experiment. The serum antibody titer at 30 weeks of age was about 20 or 65 times higher than that of chickens vaccinated with rHVT-cmvVP2 or the conventional live vaccine, respectively. rHVT-pecVP2, isolated consistently for 30 weeks from the vaccinated chickens, expressed the VP2 antigen after cultivation, and neither nucleotide mutations nor deletion in the VP2 gene was found. These results demonstrate that the amount of VP2 antigen expressed in the HVT vector was correlated with the vaccine efficacy against lethal IBDV challenge, and complete protective immunity that is likely to persist for the life of the chickens was induced.

Animals↗

Estrous-cycle-dependent variation in orthodontic tooth movement.

Sex hormones, including estradiol, play important physiological roles in bone metabolism. The purpose of this study was to investigate whether there is estrous-cycle-dependent variation in orthodontic tooth movement, and, if so, to determine the mechanism. Ten-week-old female Wistar rats were used. They received repeated orthodontic force during specific phases in the estrous cycle. Tooth movement in animals that received force principally in estrus was about 33% greater than that in animals that received such force principally in pro-estrus (p < 0.05). Serum estradiol levels also varied according to the estrous cycle, with a peak during pro-estrus and a nadir during estrus, and were inversely related to tooth movement. Furthermore, there were negative correlations between estradiol and both serum TRAP activity and pyridinoline (r = -0.42, p < 0.05; r = -0.59, p < 0.001). These results suggest that cyclic changes in the estradiol level may be associated with the estrous-cycle-dependent variation in tooth movement through its effects on bone resorption.

Acid Phosphatase↗

Diurnal variation in the response of the mandible to orthopedic force.

Bone and cartilage metabolism is known to be more active during rest than during periods of activity. The purpose of this study was to examine the hypothesis that mandibular retractive force could be more effective when applied to rats during rest. Mandibular retractive force caused a considerable reduction in the condylar length in experimental groups, and the magnitude of this reduction was greater in the Light-period (08:00-20:00) group than in the Dark-period (20:00-08:00) group. The differentiation and proliferation of chondrocytes were inhibited in animals in the Light-period group, compared with those in the Dark-period group. These results suggest that the orthopedic effects of mandibular retractive force vary depending on the time of day the force is applied, and that such force may be more effective while animals are resting than while they are active.

Analysis of Variance↗

[Outcome of rehabilitation for traumatic brain injury in the UOEH Hospital].

We investigated the outcome after patients with traumatic brain injury (TBI) were treated in our hospital. Subjects were 51 patients with TBI (43 men, 8 women; mean age 34.9 +/- 20.3 yr), who had been admitted to the department of rehabilitation in our hospital between 1980 and 2000. Data were collected retrospectively from the medical records. Most injuries were due to motor vehicle accidents. The percentage of patients who suffered impaired cognitive and behavioral functions was 86.3%. The percentage of patients who were discharged to their homes was 70.6%, but none of them could return to work. Patients who were severely disabled in their daily activities or had cognitive and behavioral disturbances were difficult to discharge. We need to establish a comprehensive rehabilitation approach to cognitive and behavioral disturbances for patients with TBI.

Accidents, Traffic↗

Workplace disability management in postpolio syndrome.

Postpolio syndrome (PPS) is generally defined as a clinical syndrome of new weakness, fatigue, and pain in individuals who have previously recovered from acute paralytic poliomyelitis. These new problems may lead to loss of employment as well as new deficits in instrumental activities in daily living (cleaning, washing, shopping, transportation, etc.), walking, climbing stairs, and personal assistance. We presented three cases of PPS with working disabilities in Japan, and stated the issues confronted with. Particularly at the workplace, PPS individuals need special supports from both rehabilitation medicine and occupational health services, including improved nutrition, achieving ideal body weight, regular and sensible exercise, frequent checkups, and modifying working conditions.

Adult↗

Screening for acetaldehyde dehydrogenase 2 genotype in alcohol-induced asthma by using the ethanol patch test.

BACKGROUND: We have previously reported that alcohol-induced asthma in Japanese patients is caused by increased blood acetaldehyde concentration resulting from abnormalities of acetaldehyde dehydrogenase 2 (ALDH2) enzyme activity on the basis of ALDH2 genotype differences. OBJECTIVES: The purpose of the present study was to determine whether the ethanol patch test could predict the ALDH2 genotype in Japanese asthmatic subjects. METHODS: An ethanol patch test on the upper arm and a questionnaire survey addressing the past history of alcohol-induced asthma were administered to 148 adult Japanese asthmatic subjects. The ALDH2 genotypes in these 148 subjects were also determined by means of PCR. RESULTS: The genotype distribution of ALDH2 determined by PCR in 68 subjects with positive ethanol patch test results was 4 (5.9%), 56 (82.4%), and 8 (11.8%) for genotypes NN (normal homozygote), NM (mutant heterozygote), and MM (mutant homozygote). The ALDH2 genotype in 80 subjects with a negative test result was only NN. The distribution of ALDH2 genotype in 78 (52.7%) subjects who had experienced alcohol-induced asthma symptoms on the basis of the questionnaire was 27 (34.6%), 44 (56.4%), and 7 (9.0%) for genotypes NN, NM, and MM, respectively. On the other hand, 70 subjects had never experienced alcohol-induced asthma symptoms. In these subjects the ALDH2 genotype was NN in 51 (72.9%), NM in 18 (25.7%), and MM in 1 (1.4%). CONCLUSIONS: Our results indicate that the results of ethanol patch testing correlate well with ALDH2 genotype, as determined by means of PCR, suggesting that the ethanol patch test is useful for the screening of alcohol-induced asthma.

Adult↗

Tooth movement and changes in periodontal tissue in response to orthodontic force in rats vary depending on the time of day the force is applied.

The purpose of this study was to investigate whether there are any differences in tooth movement or in the response of periodontal tissue to orthodontic force when the force is applied at different times of the day. One hundred 6-week-old male Wistar rats were divided into one control group without force application and three experimental groups based on the time of day the force was applied to the upper first molars. Animals in the whole-day group received force continuously throughout the experimental period, while animals in the light- and dark-period groups received force only during the light (07:00-19:00) or dark period (19:00-07:00), respectively. Tooth movement was measured using the occlusal view of a precise plaster model with a profile projector. Periodontal tissues were evaluated histologically. The time course of tooth movement varied among the groups. Tooth movement over 21 days in the whole-day and light-period groups was about twice that as in the dark-period group. The formation of new bone on the tension side in the whole-day and light-period groups was more than twice that as in the dark-period group. On the pressure side, more osteoclasts appeared on the alveolar bone in the whole-day and light-period groups than in the dark-period group. The light-period group showed less extensive hyalinization of the periodontal ligament (PDL) than the whole-day group. The area of root resorption on day 21 also varied among the groups. Interference by masticatory forces did not seem to be a principal cause of the decreased tooth movement in the dark-period group. These results indicate that there are considerable variations in tooth movement and in the response of periodontal tissue to orthodontic force when the force is applied at different times of the day in rats. The results suggest that diurnal rhythms in bone metabolism have important implications in orthodontic treatment.

Alveolar Process↗

Airway foreign body with clinical features mimicking bronchial asthma.

A 56-year-old Japanese male with persistent cough, stridor and diffuse wheezing for 6 months had obstructive pulmonary dysfunction and airway hyperresponsiveness (AHR) to inhaled methacholine. Because of a poor response to glucocorticoid therapy and neutrophilia in the peripheral blood and sputum, chest computed tomography was performed and a plate-like tumor in the truncus intermedius was identified. Fiberoptic bronchoscopy demonstrated a plate-like green-colored tumor firmly impacted into the truncus intermedius and diffuse inflammatory changes spreading to both main bronchi. A piece of 'kombu' (Japanese kelp) was successfully removed by fiberoptic bronchoscopy under general anesthesia. Pulmonary function and methacholine inhalation tests became normal after the removal of the foreign body. In this case, it is suggested that asthma-like symptoms were due to localized airflow limitation in the right bronchus as well as to AHR associated with diffuse airway neutrophilic inflammation.

Adrenal Cortex Hormones↗

Plasticity of chemotaxis revealed by paired presentation of a chemoattractant and starvation in the nematode Caenorhabditis elegans.

While the basic functioning of the nervous system of Caenorhabditis elegans has been extensively studied, its behavioural plasticities have not been fully explored because of the limited availability of assay systems. We report here a simple form of chemotaxis plasticity in this organism: when worms are starved on plates that contain NaCl, their chemotaxis towards NaCl falls dramatically. This conditioning requires both the presence of NaCl and the absence of a bacterial food source, indicating that it is not merely adaptation or habituation, but that it is likely to be a form of associative learning. While chemotaxis towards volatile chemoattractants does not change significantly after conditioning with NaCl, chemotaxis towards other water-soluble attractants does decrease. This suggests that an altered response of a cell or a group of cells specifically involved in chemotaxis towards water-soluble chemoattractants is responsible for the behavioural alteration. The decrease in chemotaxis occurred slowly over 3-4 h of conditioning and returned quickly to the original level when either of the conditioning stimuli, NaCl or starvation, was removed. The application of serotonin partially blocked this reduction in chemotaxis, consistent with the proposed function of this neurotransmitter in food signalling. Using this assay, we have isolated three mutants with reduced plasticity. This assay system expands the opportunities for studying the molecular and cellular mechanisms of behavioural plasticity in C. elegans.

Animals↗

Decreased risk of catheter infection in infants and children using subcutaneous tunneling for continuous caudal anesthesia.

Continuous caudal anesthesia has been commonly used for intra- and post-operative analgesia in infants and children. However, it has a potential risk of bacterial infection, especially in infants in whom the catheter site is easily contaminated with loose stool. To avoid infection, the authors applied a new procedure using subcutaneous tunneling for continuous caudal anesthesia. In the 18 cases studied with subcutaneous tunneling, clinical signs of infection were absent and bacterial colonization was not found on the catheter tip after 3.9 +/- 1.4 days of catheterization. The incidence of catheter colonization after continuous caudal anesthesia without tunneling had been reported. In their reports, the incidence of catheter colonization ranged from 20% to 37%. Therefore, caudal catheterization with subcutaneous tunneling is a simple and safe method, and has proved very effective to reduce the risk of epidural infection.

Anesthesia, Caudal↗

[An electrophysiological study of ropivacaine on excised cervical vagus nerves of rabbit].

Ropivacaine, a new long acting local anaesthetic of amide type is structurally related to mepivacaine and bupivacaine. This study was designed to compare the in vitro potency and neurotoxicity of ropivacaine with those of other commercially available local anaesthetics using an isolated rabbit vagus nerve model. Ropivacaine dose-dependently suppressed the evoked compound action potentials of A beta nerve and C nerve components. Minimum concentration of ropivacaine for producing complete suppression of the compound action potentials of all components was 0.008%. Electron microscopic observation showed that ropivacaine did not destroy any peripheral nervous structures in concentrations up to 0.75%. When the neurotoxic effect of ropivacaine was compared, in terms of risk ratio (clinically used concentration/concentrations producing 2 hr irreversible block), with that of commercially available local anesthetics, the rank oder was dibucaine, tetracaine, lidocaine, bupivacaine and ropivacaine.

Action Potentials↗