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Biomedical subjects

N Chino

Publications and source records attributed to N Chino.

At least 19 recordsLinked to original sources
PubMed2003

Increased concentrations of human beta-defensins in plasma and bronchoalveolar lavage fluid of patients with diffuse panbronchiolitis.

BACKGROUND: Human beta-defensin (HBD)-1 and -2 are antimicrobial peptides present in the respiratory tract. Recent reports have indicated reduced activity of beta-defensins in cystic fibrosis, suggesting that beta-defensins may play an important role in the pathological process of chronic respiratory tract infection. Diffuse panbronchiolitis (DPB) is a progressive disease characterised by frequent episodes of superimposed infection, typically caused by Pseudomonas aeruginosa. The aim of this study was to elucidate the role of these antimicrobial peptides in this disease. METHODS: The concentrations of HBD-1 and HBD-2 in plasma and bronchoalveolar lavage (BAL) fluid from 33 patients with DPB and 30 normal adults were measured by radioimmunoassay. Localisation of HBD-2 was investigated immunohistochemically in an open lung biopsy specimen obtained from a patient with DPB. RESULTS: High concentrations of HBD-1 and HBD-2 were noted in BAL fluid from DPB patients. Increased plasma concentrations of HBD-2, but not HBD-1, were found in patients with DPB compared with control subjects. In patients with DPB the HBD-2 concentration in BAL fluid correlated significantly with the numbers of cells recovered from the BAL fluid (total cells, neutrophils, and lymphocytes) and with the BAL fluid concentration of IL-1beta. Synthetic HBD-2, but not HBD-1, had dose dependent bactericidal activity against P aeruginosa. Treatment of 14 patients with macrolides significantly reduced BAL fluid concentrations of HBD-2 but not HBD-1 or plasma concentrations of HBD-1 and HBD-2. Immunohistochemistry of lung tissue showed localisation of HBD-2 in the epithelia of the distal bronchioles. CONCLUSIONS: These results indicate that beta-defensins, particularly HBD-2, participate in antimicrobial defence in the respiratory tract in DPB, and that the BAL fluid concentration of HBD-2 may be a useful marker of airway inflammation in patients with DPB.

Adult↗
PubMed2001

Functional repression of Islet-2 by disruption of complex with Ldb impairs peripheral axonal outgrowth in embryonic zebrafish.

Islet-2 is a LIM/homeodomain-type transcription factor of the Islet-1 family expressed in embryonic zebrafish. Two Islet-2 molecules bind to the LIM domain binding protein (Ldb) dimers. Overexpression of the LIM domains of Islet-2 or the LIM-interacting domain of Ldb proteins prevented binding of Islet-2 to Ldb proteins in vitro and caused similar in vivo defects in positioning, peripheral axonal outgrowth, and neurotransmitter expression by the Islet-2-positive primary sensory and motor neurons as the defects induced by injection of Islet-2-specific antisense morpholino oligonucleotide. These and other experiments, i.e., mosaic analysis, coexpression of full-length Islet-2, and overexpression of the chimeric LIM domains derived from two different Islet-1 family members, demonstrated that Islet-2 regulates neuronal differentiation by forming a complex with Ldb dimers and possibly with some other Islet-2-specific cofactors.

Animals↗
PubMed2001

Synchronization of single motor units during voluntary contractions in the upper and lower extremities.

OBJECTIVE: To investigate motor unit synchronization in the time and frequency domains and compare the amount and nature of this synchronization between upper and lower extremity muscles in human subjects. METHODS: A total of 120 motor unit pairs from biceps brachii (BB), first dorsal interosseous (1DI), vastus medialis (VM), and tibialis anterior (TA) on the dominant side were analyzed and compared. Pairs of motor unit spike trains were recorded from two concentric needle electrodes inserted within these muscles in healthy volunteers. Subjects were instructed to maintain a weak isometric contraction of these muscles so that an individual motor unit recorded from each concentric needle discharged at a steady rate of approximately 10 impulses/s. Pairs of motor unit spike trains were cross-correlated in the time domain, and coherence analysis in the frequency domain was performed on the same spike train data. RESULTS: Synchronization was seen in all the muscles studied. Strength of motor unit synchronization, expressed as synchronization index (SI), was greater in 1DI muscles compared to other muscles (P<0.01). Coherence analysis revealed significant association between motor unit firings in the 1--5 and 25--30 Hz frequency ranges in all the muscles studied. The incidence of 25--30 Hz coherence peaks were found to be greater for 1DI muscles compared to other muscles. CONCLUSION: The above results suggest a possible role for corticospinal projections in producing pre-synaptic inputs responsible for synchronization of motor unit firings and 25--30 Hz coherence peaks.

Action Potentials↗
PubMed2001

The relationships between trunk function and the findings of transcranial magnetic stimulation among patients with stroke.

In this study, we investigated the relationship between the motor evoked potentials obtained from trunk muscles and the clinical function of trunk muscle. Twenty patients with unilateral hemispheric stroke and 11 healthy adults were examined. The responses of the bilateral external oblique muscles and the erector spinae muscles to the magnetic stimulation of multiple sites over both cortical hemispheres were recorded. Trunk muscle performance was assessed using the Trunk Control Test and Stroke Impairment Assessment Set. In the stroke group, stimulation of the affected hemisphere resulted in a motor evoked potential in only one patient, while the other 19 stroke patients produced no response to stimulation of the affected hemisphere. Stimulation of the unaffected hemisphere evoked bilateral responses in 19 patients. Further, stimulation of the unaffected hemisphere in the stroke group produced larger motor evoked potentials in the ipsilateral muscles than the motor evoked potentials recorded in the ipsilateral muscles of the control group. The clinical assessment scores of trunk function (i.e. Trunk Control Test and trunk items of Stroke Impairment Assessment Set) were correlated with the amplitudes of the motor evoked potentials of the ipsilateral external oblique muscle that were evoked by stimulation of the unaffected hemisphere. Our results suggest that the recovery of trunk function after stroke is associated with an increase in ipsilateral motor evoked potentials in the external oblique muscle upon stimulation of the unaffected hemisphere, suggesting a role for compensatory activation of uncrossed pathways in recovery of trunk function.

Adult↗
PubMed2001

[Characteristics of hemiplegic outpatients with stroke who try to remove their clothes unnecessarily].

We have observed that patients who suffer from hemiplegia after a cerebral stroke, tend to remove their clothes although it is not necessary to change them while they are in hospital. Not only does this activity make it difficult to manage the ward and carry out rehabilitation, but it also often becomes problematic for home care once the patient has been discharged from hospital. However, there have been no previous reports on this activity. In this study, we examined the characteristics pertaining to clothes removal in hemiplegic patients under home care. The subjects were chronic-stage, cerebral stroke hemiplegic patients hospitalized in the rehabilitation ward of this hospital since the first initial seizure. Once it was established that environmental factors, such as room temperature, were not the primary reason for the patients to try to remove their clothes, the patients were closely monitored and the circumstances under which they tried to remove their clothes (location, time and type of clothes removed) were recorded to examine the relationship among age, sex, side affected by paralysis, higher cortical function, motor paralysis and ADL. Thirty-five percent of the patients, mostly women, usually tried to remove their clothes and the tendency was for them to incompletely remove their tops without reason while they were confined to bed or sitting on the bed. This activity was also prevalent among patients with accompanying diminished intellectual function, left hemiplegia, and left unilateral spatial agnosia. The acquired level of ADL by FIM in the group in which this activity was observed was low, except regarding meals. Thus, it was inferred that in stroke hemiplegic patients being taken care of at home the removal of clothes was related to a diminished intellectual function or ADL, which suggested the importance of family guidance based on observations of the patient's behavior in the ward. Targeting a greater number of subjects, we would like to conduct further studies on home-care measures to deal with this activity.

Activities of Daily Living↗
PubMed2000

Clinical application of the modified medially-mounted motor-driven hip gear joint for paraplegics.

PURPOSE: This paper describes a motor-driven orthosis for paraplegics which has been developed. This orthosis is composed of a medially-mounted motor-driven hip joint and bilateral knee-ankle-foot orthosis. With the gear mechanism, the virtual axis of the hip joint of this orthosis is almost as high as the anatomical hip joint. METHOD: A paraplegic patient with an injury level of T10/11 walked using bilateral lofstrand crutches and this new orthosis with or without the motor system. The motor is initiated by pushing a button attached at the edge of the grab of the crutches. RESULT: Faster cadence and speed and smaller rotation angle of the trunk was obtained in motor walking compared with non-motor walking. The patient did not feel fearful of falling. CONCLUSION: The benefit of motor orthosis is that it can be used even in patients with lower motor lesions and that it provides stable regulation of hip flexion movement in spastic patients. In conclusion, this motor orthosis will enhance paraplegic walking.

Adult↗
PubMed2000

Quantitative EMG and motor unit recruitment threshold using a concentric needle with quadrifilar electrode.

According to Henneman's size principle, small motor units are recruited before large ones. We used the electromyographic (EMG) signal decomposition technique to determine the quantitative relationships between five motor unit action potential (MUAP) parameters (amplitude, duration, area, thickness, and size index) and the recruitment threshold of the motor units recruited up to 50% of the maximum voluntary contraction in the first dorsal interosseous, biceps brachii, rectus femoris, and tibialis anterior muscles of 5 healthy young men. In each muscle, the amplitude, duration, area, and size index had significant, positive high correlations with the motor unit recruitment thresholds. We conclude that the size principle applies to recordings made with concentric needle EMG electrodes under special recording conditions, and therefore that more importance should be attached to the patient's contraction force during EMG examinations in order to evaluate MUAPs for electrodiagnostic purposes.

Adult↗
PubMed2000

Motor unit sound in needle electromyography: assessing normal and neuropathic units.

Motor unit action potentials (MUPs) recorded by a monopolar needle electrode in normal and neuropathic muscles were computer-simulated. Five experienced electromyographers acted as examiners and assessed the firing sounds of these MUPs without seeing them on a display monitor. They judged whether the sounds were crisp or close enough to accept for the evaluation of MUP parameters and whether, when judged acceptable, they were neuropathic-polyphasic. The examiners recognized motor unit (MU) sound as crisp or polyphasic when the MUP obtained was 0.15-0.2 mm from the edge of the MU territory. When the intensity of the sound decreased, they were unable to perceive it as crisp. When the intensity exceeded the saturation level of loudspeaker output, the sound was perceived as polyphasic, but the wave form of the MUP was not. When the frequency of the neuropathic MUP was lowered, the examiners were unable to determine whether the MUP was polyphasic. MUPs recognized as acceptable for evaluation can be distinguished by listening to MU sounds. The audio amplifier gain must be appropriately adjusted for each MUP amplitude in order to assess whether an individual MU sound is crisp or polyphasic before MUP parameters are measured on a display monitor.

Adult↗
PubMed2000

Tonic and kinetic motor units revisited: does motor unit firing behavior differentiate motor units?

OBJECTIVE: We tried to differentiate motor unit into two distinct populations, tonic and kinetic, on the basis of the relationship between the mean inter-spike interval and its variability. METHODS: During voluntary isometric contraction myoelectric activity was recorded with a special quadrifilar electrode from first dorsal interosseous, biceps brachii, soleus, and tibialis anterior muscle. Motor unit action potentials (MUAP) were decomposed into individual MUAP trains, by electromyography (EMG) signal decomposition. The variability in the instantaneous firing rate was assessed at two or more levels of contraction in each muscle. RESULTS: We found each muscle tested had a homogeneous population. There were no tonic and kinetic motor units. But there were differences in the variability in the instantaneous firing rate in the 4 muscles tested. CONCLUSION: Motor unit firing behavior in a muscle may be fitted for its function.

Action Potentials↗
PubMed2000

The stroke impairment assessment set: its internal consistency and predictive validity.

OBJECTIVE: To study the scale quality and predictive validity of the Stroke Impairment Assessment Set (SIAS) developed for stroke outcome research. DESIGN: Rasch analysis of the SIAS; stepwise multiple regression analysis to predict discharge functional independence measure (FIM) raw scores from demographic data, the SIAS scores, and the admission FIM scores; cross-validation of the prediction rule. SETTING: Tertiary rehabilitation center in Japan. PATIENTS: One hundred ninety stroke inpatients for the study of the scale quality and the predictive validity; a second sample of 116 stroke inpatients for the cross-validation study. MAIN OUTCOME MEASURES: Mean square fit statistics to study the degree of fit to the unidimensional model; logits to express item difficulties; discharge FIM scores for the study of predictive validity. RESULTS: The degree of misfit was acceptable except for the shoulder range of motion (ROM), pain, visuospatial function, and speech items; and the SIAS items could be arranged on a common unidimensional scale. The difficulty patterns were identical at admission and at discharge except for the deep tendon reflexes, ROM, and pain items. They were also similar for the right- and left-sided brain lesion groups except for the speech and visuospatial items. For the prediction of the discharge FIM scores, the independent variables selected were age, the SIAS total scores, and the admission FIM scores; and the adjusted R2 was .64 (p < .0001). Stability of the predictive equation was confirmed in the cross-validation sample (R2 = .68, p < .001). CONCLUSIONS: The unidimensionality of the SIAS was confirmed, and the SIAS total scores proved useful for stroke outcome prediction.

Adult↗
PubMed2000

Physiologic decrease of single thenar motor units in the F-response in stroke patients.

OBJECTIVE: To investigate the left-right difference and the reproducibility by the F-wave motor unit number estimation and to compare the motor unit number between the hemiplegic and unaffected side in stroke patients. SETTING: A referral center and institutional practice providing outpatient care. SUBJECTS: Seven healthy volunteers and 15 consecutive stroke patients. DESIGN: Diagnostic statistical test and correlational study. METHOD: Submaximal stimuli were used to evoke a sample of surface motor unit action potentials (S-MUAPs) in the F-waves that are entirely representative of the relative numbers of detected S-MUAPs of different sizes. The average S-MUAP amplitude was calculated from a selected population of F-wave responses for each abductor pollicis brevis (APB) muscle. The motor unit number was calculated by dividing the maximum M-potential negative peak amplitude by the average S-MUAP negative peak amplitude. RESULT: There was no statistical difference between motor unit numbers on either side and between test and retest in this motor unit number estimation method among normal subjects. The motor unit number on the hemiplegic side was significantly lower than on the unaffected side (p < .05, Mann-Whitney test) among stroke patients. CONCLUSION: The motor unit could decrease in the hemiplegic side after a moderate-to-severe hemiplegic stroke and this decrement might be due to the transsynaptic degeneration secondary to an upper motor neuron lesion.

Action Potentials↗
PubMed2000

Current status of rehabilitation, especially in patients with stroke, in Japan.

The current status of stroke rehabilitation in Japan was reviewed from the perspectives of epidemiology, structures, outcomes and research. Japan is the fastest aging society in the world, facing a rapid increase in its disabled population and ensuing healthcare costs. Although its mortality is decreasing, stroke is the most frequent cause of disability. Traditionally, stroke patients acutely admitted to general hospitals remained bed-ridden for months, hindering maximal functional gain. With more attention to the importance of rehabilitation, improved outcomes such as shorter length of stay, more functional gain and increased community discharge have resulted. Japan's healthcare system, characterized by universal coverage, equity and a mandatory fee schedule, has contributed to the world's longest life expectancy and the lowest infant mortality rate, but it has also lacked quality assurance. Under stringent economic conditions, drastic healthcare and welfare reform plans are being debated and pressure is mounting for more efficient stroke rehabilitation.

Aged↗
PubMed2000

Structural analysis of human beta-defensin-1 and its significance in urinary tract infection.

Human beta-defensin-1 (hBD-1) is a 36-amino-acid antimicrobial peptide that functions in the host innate defense. We developed a highly sensitive radioimmunoassay for hBD-1 and identified several hBD-1 peptides in human kidney, urine, and plasma by amino acid sequencing and mass spectrometry. Large quantities of hBD-1 peptides are produced in the kidney, are released into the tubular lumen as 47-amino-acid pro-hBD1, and then undergo proteolytic processing and generate multiple truncated forms. The respective urine and plasma concentrations of hBD-1 in patients with pyelonephritis are 48.1 +/- (SEM) 15.7 pmol/mg creatinine and 2.66 +/- 0.41 pmol/ml, 3.1-fold and 1.8-fold those of normal individuals. hBD-1 is thought to contribute to mucosal defense in the urinary tract. Our findings provide a better understanding of the biosynthesis of this peptide and its pathophysiological significance in infectious diseases.

Adult↗
PubMed2000

Rise time or rise rate: which should be a criterion for analysing motor unit action potentials?

We measured the rise time (RT) and rise rate (RR) of motor unit action potentials (MUAPs) when sharp sounds are heard in concentric EMG in the first dorsal interosseus muscle (FDI) and biceps brachii muscle (BIC) of normal subjects. MUAPs from FDI muscle with an RT of less than 500 microseconds were 85%, and those of more than 500 microseconds were 15%. In contrast, MUAPs from BIC muscle with an RT of less than 500 microseconds were 65%, and those of more than 500 microseconds were 35%. Distributions of the RR for FDI and BIC were also determined. MUAPs from FDI muscle with an RR more than 0.3 mV/ms were 98.3%, and those of less than 0.3 mV/ms were 1.7%. In contrast, MUAPs from BIC muscle with an RR of more than 0.3 mV/ms were 93%, and those of less than 0.3 mV/ms were 7%. We conclude it is better to use RR than RT when accepting MUAPs in clinical EMG, because even when sharp sounds are heard, MUAPs do not always have an RT of less than 500 microseconds. The use of RT and the sharpness of MUAPS therefore need to be reconsidered, or RR should be used in clinical EMG by automatic program.

Action Potentials↗
PubMed2000

[Treatment of pressure sores accompanied by infection in outpatients with spinal cord injury].

The occurrence of infection at pressure sore sites due to multiple drug resistant microbes not only delays healing at the time of infection, but it can become a major factor preventing an acceptable level of ADL (activities of daily living) in the home. We studied a method for treating infection in pressure sores in spinal cord injury patients living at home who were commuting to our hospital for treatment. After establishing drug sensitivity in all patients, we instructed patients and their families how to apply dressings using 2% chloramphenicol (CP) ointment, and then studied the status regarding infection and the course of the pressure sores. Considerable Proteus vulgaris, E. faecalis, P. aeruginosa, and methicillia resistant staphylococcus aureus (MRSA) were detected in cultures from all patients. After the start of treatment at home, the casual microbes disappeared over time, and improvement was seen, including according to the Shea classification, with time from the infection. This was thought to be due to a decrease in the frequency of use of CP at the clinic and a subsequent increase in sensitivity. It was inferred from these results that the local administration of antibacterial CP ointment in the home at the time of infection is effective against pressure sores.

Adult↗
PubMed1999

Relationship between hypoxemia and fibrillation potential firing rate in denervated muscle.

The effects of hypoxia and ischemia on the firing rate of fibrillation potentials in denervated rat muscle were examined. We recorded electromyograms from the denervated left extensor digitorum longus muscle. Hypoxia was induced by low-oxygen ventilation. Ischemia was established by ligating the abdominal aorta and inferior vena cava, with or without extracorporeal hindlimb perfusion. The fibrillation potential firing rate correlated with the PaO2 (P < 0.0001) and temperature (P = 0.0001). Fibrillation potentials disappeared after the initiation of ischemia and reappeared after restitution of blood flow; they disappeared during ischemia with extracorporeal perfusion. The attenuation curves for the firing rate of fibrillation potentials during ischemia were well-described by exponential curves, but there was no significant difference in the attenuation constants for circulatory arrest and perfusion with a physiologic salt solution. We conclude that the fibrillation potential firing rate is proportional to oxygen supply, presumably because of the rate of aerobic metabolism.

Action Potentials↗
PubMed1999

Osteoporosis in hemiplegic stroke patients as studied with dual-energy X-ray absorptiometry.

OBJECTIVES: To compare bone mineral densities (BMDs) of the affected and unaffected limbs in stroke patients at multiple sites; to study longitudinal changes during a 3-month rehabilitation program; and to relate BMDs to demographic, impairment, and disability variables. DESIGN: Descriptive study. SETTING: Tertiary rehabilitation center. PATIENTS: One hundred four consecutive hemiplegic inpatients, 69 men, age 56.5 +/- 13.2 yrs, 47 with left-sided brain lesion. Median days from onset to admission and median length of stay days were 83 and 105.5, respectively. MAIN OUTCOME MEASURES: BMDs of proximal humerus, distal radius, femoral neck, and calcaneus bilaterally, and third lumbar vertebra, measured with dual-energy x-ray absorptiometry (DXA), were compared between affected and unaffected sides at admission and discharge. RESULTS: Stroke Impairment Assessment Set (SIAS) motor scores, Functional Independence Measure (FIM) scores, grip strength, and awake/sleep heart rate counts (activity index) improved significantly at discharge. Affected/unaffected BMD ratios were 88.3% to 98.4% at admission and 79.6% to 98.8% at discharge, lowest for the humerus. Discharge/admission ratios were 89.1% to 97.8% for the affected and 97.4% to 100% for the unaffected side. All BMDs were intercorrelated (R = .438 to .873). They correlated significantly with age, body weight, grip strength, FIM scores, and activity index. Factors selected to explain BMD with multiple regression analysis differed according to the site and timing of the measurement. CONCLUSIONS: BMDs of the affected side were lower and most marked in the humerus. Longitudinally, not only the affected but the unaffected BMDs decreased. Age, sex, duration of stroke, anthropometric measurements, motor paralysis, muscle strength, and activity level contributed differently to bone loss according to the site and timing of the measurement.

Absorptiometry, Photon↗