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Biomedical subjects

I Homma

Publications and source records attributed to I Homma.

At least 109 records · Page 6Linked to original sources
PubMed1982

Inhibitor effect of acupuncture on the vibration-induced grasp reflex in man.

The effect of acupuncture on the grasp reflex caused by mechanical vibrations of fingers produced by a cylinder-type vibrator (120 Hz) was studied in healthy man. As the hand grasped the vibrator during vibration, the volar surface of all fingers was simultaneously stimulated, resulting in a gradually increased force of the grasp, the vibration-induced grasp reflex (VGR). The VGR was inhibited by acupuncture with needles inserted into three acupuncture points (Shou Sanli, Chicheng and Szutu), but not into other sites in the hand.

Acupuncture Therapy↗
PubMed1982

The inhibitory effect of acupuncture on the tonic vibration reflex (TVR) in man.

The effect of acupuncture on the tonic vibration reflex (TVR) has been examined in healthy men. Vibrations (100 Hz) were applied over the muscle bellies of either finger flexion muscles or extension muscles, while finger flexions and extensions were measured by a strain attached to the middle finger. A stainless steel acupuncture needle was inserted for 10 min into an acupuncture point named "Chu-Chih (LI-II)". After the application of acupuncture, TVRs in both flexion and extension muscles were significantly less than those observed before the application of acupuncture. The inhibitory effect of acupuncture almost disappeared 10 min after removing the needle. Acupuncture transiently inhibits TVR in extension and flexion muscles in man.

Acupuncture Therapy↗
PubMed1982

Elimination of EKG artifacts from EEGs recorded with balanced non-cephalic reference electrode method.

The EKG artifacts contaminating EEGs recorded by the balanced non-cephalic reference electrode system were removed from EEGs by using a device composed of a one channel averager and simple hardware. This device has the following advantages to the others which have been previously proposed: (1) it is possible by averaging of a few (i.e., 5) EKG artifacts in EEG records successfully with only one channel averaged EEG derived from an earlobe; (2) the averaged EKG pattern is able to follow rapid EKG pattern change due to altered body position; (3) the possibility of being affected by another kind of artifact was decreased, because the time of averaging process to obtain averaged EKG became shorter. A remaining problem in achieving a complete removal of EKG artifacts (maximally of 100 micro V) was beat-by-beat small changes in EKG wave forms due to the respiratory cycle. Therefore, it was felt that our method was sufficiently accurate for clinical examination of EEG.

Computers↗
PubMed1981

Chemosensitivity in patients with diabetic neuropathy.

1. By using the rebreathing method, ventilatory responses to inhaled CO2 were studied in patients with diabetic neuropathy. 2 Their general respiratory functions including vital capacity (VC) and forced expiratory volume in 1 s (FEV 1.0) were within normal ranges and ventilatory responses to CO2 in the range 5.32--5.99 kPa were not significantly different between patients and normal subjects. However, ventilation in the patients was significantly less than that in normal subjects when the alveolar partial pressure of CO2 (PACO2) was above 6.65 kPa. 3. The slope of the CO2 response curves obtained during hyperoxic rebreathing was significantly less in the patients than in the normal subjects. In the patients CO2 response curves with 15% (v/v) O2 were either the same or had lower slopes than those measured with 100% O2. 4. The results suggest that both peripheral and central chemosensitivity, including the activity of the respiratory centre, are reduced in patients with diabetic neuropathy.

Adult↗
PubMed1981

Some characteristics of sleep spindles derived from automatic analysis.

Sleep spindles in eight normal adults were analyzed automatically by a minicomputer. The accuracy of spindle detection was about 90%. Spindle wave frequency was measured by an approximation method for the spindle peaks; this method employed a quadratic equation on prior analog filtering. The accuracy of measurement was within 0.6 msec (SD 1). The average spindle wave frequency was about 13 Hz, but varied depending on the sleep stage and brain region. The frequency was highly variable and displayed no tendency. Concerning spindle duration, short spindles were followed by either short or long spindles, while long spindles rarely were followed by long ones. As sleep progressed, spindle duration tended to become shorter. There was a tendency for one long interval of spindle appearance not to be followed by another long interval of appearance. However, as sleep progressed, the interval of spindle appearance had a tendency to become prolonged.

Adult↗
PubMed1981

Characteristics and rate of occurrence of spontaneous and provoked augmented breaths.

The tidal volume and corresponding efferent phrenic activity of spontaneously occurring and provoked "augmented" breaths, AB, and the subsequent post-augmented breaths were studied in cats anesthetized with pentobarbitone during hypercapnia and hypoxia. The augmentation phase (phase II) begins at, or close to, the crest of what appears as a "normal" inspiration (phase I). The amplitude and duration of phase II remained fairly constant whereas the amplitude and the duration of phase I changed with chemical drive just as in control breaths. The smaller amplitude and shorter duration of post-augmented breaths as compared to control breaths seems to be due to both a lower-than-normal inspiratory "off-switch" threshold following the AB and an increased rate of rise of inspiratory activity. With increasing hypercapnia and hypoxia both the time interval between AB and the refractory period following an AB during which a new AB cannot be provoked were reduced. Following bilateral vagotomy AB was temporarily abolished but reappeared after 1-2 h. The relatively low rates of occurrence after vagotomy still showed the same type of dependence on chemical stimuli. The refractory period was not abolished although usually decreased by gallamine paralysis or high thoracic spinalization.

Animals↗
PubMed1981

Ventilatory responses to carbon dioxide and hypoxia during acupuncture anesthesia in rabbits.

Ventilatory responses to CO2 or hypoxia were examined in rabbits during acupuncture anesthesia and compared with responses during pentobarbital anesthesia. The responses during pentobarbital anesthesia were significantly less than those during acupuncture anesthesia. The results showed that acupuncture analgesia was effective during performance of these experiments.

Acupuncture Therapy↗
PubMed1981

Effect of chest wall vibration on ventilation in patients with spinal cord lesion.

Changes of respiration caused by chest wall vibration were studied in 13 patients with cervical cord lesions. Vibrators applied on the chest wall were intermittently triggered by the patient's respiratory movements. The vibrators were triggered to be applied in three ways. 1) Upper vibrations were bilaterally applied during inspiration on the 2nd or 3rd parasternal intercostal spaces (insp "in-phase" vibration). 2) Lower vibrations were bilaterally applied during expiration on the 7th-to 10th intercostal spaces anterior to midaxillary lines (exp "in-phase" vibration). 3) Inspiratory and expiratory vibrations were combined to produce alternating in phase vibration. Both inspiratory and expiratory vibrations increased tidal volume (VT), but the alternating in-phase vibration increased it to significantly higher values (P less than 0.05). Minute volume of ventilation (VE l/min) also increased with insp or exp in-phase vibration. The alternating in-phase vibration increased VE l/min to even higher values (P less than 0.05). The responses described probably depend on segmental vibration reflexes arising in the inspiratory and expiratory intercostal muscles underlying the vibrators. The alternating in-phase vibration may well be useful to improve the breathing in patients with respiratory insufficiency.

Adolescent↗
PubMed1980

Inspiratory inhibitory reflex caused by the chest wall vibration in man.

The effects of chest wall vibrations on tidal volume (VT), inspiratory time (TI) and expiratory time (TE) were measured in normal man during rebreathing. Two vibrators, frequency 100 HZ, were applied bilaterally over the 7th to 10th intercostal spaces anterior to the mid-axillary line. The vibrators were triggered by chest wall movement during the inspiratory phase once or twice, intermittently, every 4-10 breaths. The VT and TI of "vibrated" breaths were decreased compared with preceding control breaths. These effects were clearly paralleled by a reduction in averaged integrated EMG recordings from the diaphragm. The initial time course of the integrated EMG activities in vibrated and non-vibrated breaths were almost equal. However, the relationship between VT and TI of vibrated breaths was shifted downward from that of the non-vibrated (control) breaths. The depression of VT was augmented as the VT of control breath increased. The findings suggest that supraspinal intercostal inhibitory reflex normally contributes to the phase switching mechanism of respiration in man.

Adolescent↗
PubMed1980

Inhibitory effect of acpuncture on the vibration-induced finger flexion reflex in man.

The effect of acupuncture on the tonic finger flexion reflex caused by mechanical vibration of the index finger was studied in healthy man. The volar side of the index finger was tapped by a vibrator (100 Hz), while flexion forces were recorded. A silver needle inserted into the acupuncture point (Wai-Kuan) inhibited the vibration-induced finger flexion reflex. In this study, the inhibitory effect of acupuncture on the reflex contraction, rather than pain sensation and analgesia, was demonstrated.

Acupuncture Therapy↗
PubMed1979

Experimentally induced Cheyne-Stokes breathing.

We have studied the propensity for periodic breathing to occur in cats anaesthetized with pentobarbitone breathing either spontaneously or with the aid of a 'servo-respirator' governed continuously by the efferent phrenic nerve activity. Sustained periodic breathing could be induced increasing 'controller gain', either by increasing the gain of the respirator, or by lung deflation, which reflexly increased controller responses to both hypoxia and hypercapnia. Periodic breathing was potentiated both by hypoxia and by diminishing the central (CO2, H+)-drive by focal cooling at the ventral surface of the medulla, two procedures which increase the relative influence of hypoxic drive. Less hypoxia was needed to produce periodic breathing at high rather than low controller gains. Reducing controller gain to zero by constant artificial respiration always abolished periodic breathing. Periodic breathing was also eradicated when the relative importance of CO2 drive was enhanced by breathing the cats with CO2-enriched gas mixtures or with 100% O2. The results are consistent with theoretical predictions for the occurrence of oscillations in the mechanisms for the chemical control of breathing and indicate that increasing controller gas can produce periodic breathing. The results further emphasize the importance of the (CO2, H+)-drive in preserving ventilatory stability.

Animals↗
PubMed1979

Graded changes in central chemoceptor input by local temperature changes on the ventral surface of medulla.

1. In cats under pentobarbitone anaesthesia the effects of focal temperature changes of the ;chemoceptive' areas on the ventral surface of medulla, described by Loeschcke and his associates, were studied with respect to tidal volume, V(T), tidal variation in efferent phrenic activity, Phr(T), and respiratory rate. The cats were either paralysed and ventilated at various constant P(A,CO2) and P(a,O2) levels, or breathing spontaneously.2. It was confirmed that focal bilateral cooling of the intermediate, ;I((S))', areas caused rapid depression of respiration even at constant artificial ventilation. In normocapnic and normoxic conditions apnoea usually ensued at brain surface temperatures of 20-22 degrees C.3. The effects were graded along continuous temperature-response curves with enhancements of ventilation above and depression below normal body temperature.4. The strongest effects on V(T) and Phr(T) were obtained from the I((S)) areas with no or only small effects on inspiratory or expiratory timing in the vagotomized animal. The Hering-Breuer inflation reflex and its effects on timing and amplitudes were not affected by cooling this area.5. Focal cooling of the caudal or the rostral ;chemoceptive' areas, ;C((L))' and ;R((M))' areas, caused smaller effects on V(T) and Phr(T) but produced significant effects on respiratory rate even after vagotomy.6. The effects of focal cooling of these areas could be mimicked by topical application of procaine solution which has been shown not to penetrate deeper than 100 mum from the surface.7. Moderate focal cooling of area I((S)) to temperatures above 28-30 degrees C caused a parallel shift in the CO(2)-response (V(T), Phr(T)) curves to the right with little change in slope. The P(CO2) thresholds for apnoea were correspondingly raised. These focal temperature effects could be compensated by changes in P(CO2) with, on the average, 2.7 torr/ degrees C. Focal temperatures below 28 degrees C usually caused some decrease in slope of the CO(2)-response curves in addition to further shifts.8. Added hypoxic stimulus or electrical stimulation of the carotid sinus nerves caused an almost parallel increase of Phr(T) at all P(CO2) levels and all focal temperatures suggesting an additive type of interaction between the input from the peripheral chemoreceptors and that from the central (CO(2), H(+)) sensing structures whether the latter was altered by changing P(CO2) or by focal temperature changes on the I((S)) areas.9. In contrast to these effects of hypoxia and stimulation of the carotid sinus nerves the reflex increase of inspiratory activity caused by lung deflation or by electrical stimulation of the glossopharyngeal nerve distal to the carotid sinus nerves was CO(2) dependent. These reflex effects decreased with focal cooling of the I((S)) areas as with hypocapnia, suggesting a mainly multiplicative or ;gain-changing' type of interaction with the central chemoceptive drive.10. The close similarities in effect of focal cooling and of hypocapnia on the different respiratory parameters even during constant artificial ventilation indicate that focal temperature changes of the I((S)) areas intervene effectively with the normal ventilatory response to CO(2) without changing the chemical or physical environment of those neural structures in the brain stem which set respiratory pattern.

Animals↗