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Biomedical subjects

N Ohya

Publications and source records attributed to N Ohya.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Effect of posture on pharyngeal area measured by acoustic reflection technique].

Patients with obstructive sleep apnea (OSA) have a smaller pharyngeal area (PA) and higher compliance than normal subjects. The apnea-hypopnea index (AHI) in OSA patients determined by polysomnographic study was greater in the supine than lateral position. Recently there have been reports of reduction in the PA by the acoustic reflection technique (ART) in the supine position. However, there has been no report on the PA measured by ART in the lateral position which is important in the treatment of OSA. To evaluate differences in the PA with posture changes, we measured the PA in 41 normal subjects (11 males and 30 females) in the sitting, lateral and supine positions by ART. The average PA in the sitting position in the males and females was 3.8 +/- 0.6 cm2, and 3.3 +/- 0.5 cm2, respectively. The average PA in the lateral position in the males and females was 3.5 +/- 0.6 cm2, and 3.1 +/- 0.5 cm2, respectively. The average PA in the supine position in the males and females was 2.9 +/- 0.5 cm2, and 2.7 +/- 0.4 cm2, respectively. PA in the sitting position correlated well with body surface area (BSA). The average PA in both the males and females was significantly smaller in the supine than in the sitting position. The average PA in the lateral position in both males and females was significantly smaller than that in the sitting position and was significantly larger than that in the supine position. Decrease in PA with posture (from sitting to lateral) in the males (9.2 +/- 5.5%) was similar to that in the female (5.7 +/- 5.4%). Decrease in PA with posture (from sitting to supine) was significantly larger in male (24.4 +/- 9.5%) than in female (16.6 +/- 6.8%). We conclude that the decrease of PA in the supine position is ameliorated in the lateral position in normal subjects. Lateral position may be the preferred sleeping position in snoring or OSA patients.

Adult↗
PubMed1991

[CNS disorders caused by metabolic disorders].

A guideline for early diagnosis of metabolic disorders affecting central nervous system during neonatal and early infancy was presented. Clinical manifestations associated with inborn errors of metabolism in the neonatal period are poor feeding, vomiting, diarrhea, abnormalities in muscle tonus, dyspnea, convulsion, coma and so on, and these are not specific to each disorder. However, such symptoms or signs as described below have often intimate relation to metabolic disorders: (1) previous children died of undetermined causes during early infancy; (2) complication of sepsis; (3) onset in the early neonatal period; (4) developmental and growth retardation. When newborns and infants have these symptoms or signs, we should start simple screening studies immediately for metabolic disorders, including CBC, hepatic function tests, blood glucose, lactate, pyruvate, ketone bodies, ammonia, blood gas analysis, urinalysis (including non-glucose reducing substance tests and FeCl3 reaction) and so on. As for CBC, we have to make our own effort to find spherocytosis and vacuoles in lymphocytes. Family history, especially the mother's personal history, is indispensable. During physical examinations, we must pay attention to facial appearance, skin color, macroglossia, hair abnormalities, peculiar odor of the urine and hepatosplenomegaly. When abnormality is found in these clinical signs or simple laboratory examinations, we should not hesitate to start dietary treatment even if special examinations for differential diagnosis are on the way.

Blood Gas Analysis↗
PubMed1990

Beta-adrenergic drug therapy in newborn canine endotoxic shock.

The mortality of septic shock remains high in newborns. Although the effectiveness of adrenergic drug therapy continues to be controversial, adrenergic drugs have been used for the treatment of newborn endotoxic shock. To elucidate the effects of beta-adrenergic drugs on the fulminant hemodynamic deterioration of newborn endotoxic shock, newborn dogs (2-10-day-old, 264-800 g) were given Escherichia coli lipopolysaccharide (LPS; 10 mg/kg iv) and treated with isoproterenol (0.1 micrograms/kg/min) or dopamine (5 micrograms/kg/min) infusion from 5 to 120 min after LPS injection. Isoproterenol attenuated the effects of LPS by increasing the mean arterial pressure (32 +/- 2 vs. 13 +/- 1 mmHg at 120 min), cardiac output (183 +/- 29 vs. 118 +/- 23 ml/min/kg at 120 min), and the survival time (5.3 vs 2.9 hr). However, dopamine did not improve the hemodynamic deterioration. As dopamine-beta-hydroxylase activity in the blood was significantly lower in newborn dogs than in adult dogs, inadequate response of newborn dogs to dopamine was thought to be in part due to enzymatic immaturity.

Adrenergic beta-Agonists↗
PubMed1990

[Pharyngeal area measured by acoustic reflection technique while breathing room-air].

Although there have been many reports on the airway area measured by breathing 80% He-20% O2 (He-O2) using the acoustic reflection technique (ART), there have been no reports on that by breathing room-air (Air) because of the lack of accuracy in evaluating the trachea. When measuring with He-O2, accidental introduction of Air into the airway makes the measurement inaccurate. Moreover, it is a time-consuming method and is hardly applicable to dyspneic patients. Therefore, we tried to assess whether the airway area, especially the upper airway, can be measured while breathing Air. In order to compare the areas determined by the two methods, area-distance functions from the pharynx to the trachea were arbitrarily divided into 9 divisions at interval of 2.8 cm. Each of these divisions was respectively compared. We took averages of the pharyngeal, tracheal areas in 8 normal subjects. We found no significant difference between the oropharyngeal area measured by breathing Air and that measured by breathing He-O2, and found a significant correlation between them. There was a significant correlation between the hypopharyngeal areas when using the two methods. The average tracheal area by breathing Air is 4.96 +/- 0.50 cm2, which is 40% above that when measured using He-O2 (3.55 +/- 0.32 cm2). In contrast, the average pharyngeal area when breathing Air is 4.13 +/- 0.93 cm2, which overestimates that by breathing He-O2, namely 3.54 %/- 0.84 cm2 by only 17%. In conclusion, it is possible and useful to estimate the pharyngeal area by breathing Air.

Acoustics↗
PubMed1990

[Tooth movement of an impacted lower 2nd premolar in the root developmental stage--a follow-up radiographic observation on the root formation].

A 9 year old girl presented an impacted lower right 2nd premolar which not only was in horizontal position, but its crown was directed lingually. As a lower right 2nd premolar was in such a position that normal eruption was impossible, the deciduous predecessor was extracted at 9 years of age, and then sufficient space had been created for the lower right 2nd premolar to be erupted, and the eruption of it was observed for about 2 years. 2 years later, radiographic indication showed that no spontaneous eruption of a lower right 2nd premolar was to be expected. At 11 years of age, surgical exposure and traction of a lower right 2nd premolar was attempted. When the lower right 2nd premolar was upright, its root formation was in the 1st stage of root developmental stages according to Moorrees et al. Follow up radiographic observations on surgical exposure and traction of a lower right 2nd premolar 3 years later revealed the following results: 1. The root development went on to amount to about 90 percent of the root formation of the other tooth concerned without the curvature of the root. 2. Lamina dura and periodontal space were normal. The continued root formation was narrowing the root apex and the pulpal tissue of apical foramina was continuous with the periodontal space surrounding the root. 3. Bone deposition occurred at the alveolar crest and the latter was recontoured normally. The interdental and inter-radicular trabecula were good. As based on these results, normal development of the root of a lower right 2nd premolar with normal periodontium can be anticipated. Clinically, the lower right 2nd premolar had completely erupted and was in normal position on the arch and in occlusion. Color, vitality and mobility were normal. Periodontal support was good. The above-mentioned findings give support to the possibility that "early treatment" enables the impacted tooth to correct.

Bicuspid↗
PubMed1989

A histopathological study on the prognosis of childhood IgA nephropathy and glomerular basement membrane lesions.

Seventy-three patients with IgA nephropathy (IgAGN), under the age of 15 years at the time of the discovery of the disease, were investigated with respect to glomerular basement membrane (GBM) lesions. Irregular attenuation or widening of GBM, especially on the epithelial side, was observed in 28 cases (38%). These two changes are referred to as lysis of GBM and were considered to be the primary and specific changes among the GBM lesions in IgAGN. GBM thickening with layering of lamina densa was found in 37 of 73 cases (51%), but this change has been observed in other types of glomerular diseases. GBM lesions similar to those seen in IgAGN were also observed in Henoch-Schönlein purpura nephritis (HSPN) and poststreptococcal acute glomerulonephritis (PSAGN). Lysis of GBM was observed only in IgAGN, HSPN and PSAGN. Subepithelial and intramembranous deposits appeared to have an important role in the development of these GBM lesions. The presence of GBM lesions was correlated with a high incidence of cellular crescents but not with other clinical or light microscopic findings. The presence of these GBM lesions in IgAGN does not have a significant effect on the prognosis, at least in childhood. The affected GBM seemed to recover without leaving any significant residual damage in most cases. In the long-term prognosis of the disease non-immunological factors, such as ageing or hypertension, seem to be important.

Adolescent↗
PubMed1989

Mouth pressure curve on abrupt interruption of airflow during forced expiration.

An attempt was made to investigate how the mouth pressure curve represents the process of air flowing into the collapsed segment downstream to the choke point when the airflow is abruptly interrupted at the mouth during forced expiration. Immediately after the interruption of airflow, the mouth pressure suddenly increased (phase 1), followed by a slower rise in pressure (phase 2) within approximately 100 ms until the pressure reached the alveolar pressure. The pleural and alveolar pressures remained constant during this process. The first phase of the abrupt rise represented the pressure induced by the instantaneous interruption of the airflow itself. Analysis of the supramaximal flow (Vsupramax) observed after resumption of the airflow suggested that the choke point remained constant during the second phase of the mouth pressure after interruption of maximal flow (Vmax). From these results, examination of the second phase of the mouth pressure curve may provide useful information about the downstream segment of the airway.

Adult↗
PubMed1989

Airway pressure-volume curve estimated by flow interruption during forced expiration.

We attempted to estimate the pressure-volume characteristics of airways downstream from the choke point when the airflow was abruptly interrupted during forced expiration. The change of gas volume of the downstream segment after interruption could be estimated by multiplying the maximum flow (Vmax) immediately before interruption by the interruption time because the Vmax is maintained for a short period after airflow interruption at the mouth, as described in our previous report (J. Appl. Physiol. 66: 509-517, 1989). For the pressure of the downstream segment, we used the mouth pressure itself. Airway compliance, a slope of the pressure-volume curve, was measured in an airway model in eight normal subjects, in six patients with chronic obstructive pulmonary disease (COPD), and in one patient with tracheobronchopathia osteochondroplastica. Airway compliance was 0.96 ml/cmH2O in normal subjects and 2.49 ml/cmH2O in COPD patients. This difference of airway compliance was believed to be caused by the longitudinal expansion of the downstream segment and changes in the properties of the airway wall.

Adult↗
PubMed1989

High-frequency ventilation by bilateral phrenic nerve stimulation in dogs.

We succeeded in achieving good gas exchange by oscillatory phrenic nerve stimulation (PNS) in dogs. In 7 out of 14 dogs, adequate gas exchange was attained by PNS at 3, 4 and 5 pulses per sec (pps). VE increased with stimulation frequency up to 4 or 5 pps, but decreased above 6 pps. We also applied sinusoidal oscillation using a piston pump at the trachea in the same dogs to analyze the mechanical properties of the respiratory system. The V/P ratio, oscillatory volume divided by driving pressure, decreased markedly at 6 Hz while the pleural pressure remained constant up to 10 Hz. These facts indicate that the fall in VE is due to mechanical properties of the airway and lung, and not due to failure of the ventilatory pump system. We conclude that frequencies of 3-5 pps in high-frequency ventilation are optimal for maintaining effective gas transport when the diaphragma is used as the oscillatory generator.

Animals↗
PubMed1989

[Senile type atopic dermatitis].

Twenty-five patients older than 50 years with atopic dermatitis (AD) diagnosed by the criteria of Tokyo Medical College were investigated on the basis of clinical course and features, IgE RIST, skin reactions, IgE RAST score to several antigens, and IgG4 levels in order to clarify the character of senile AD. The results were compared with the data from younger patients. It was found that the senile type AD showed various type of eczematous lesions whose onset was in the fourth decade of life, and higher IgE RIST and IgG4 levels than healthy people, but lower than younger AD patients. Immediate skin reactions to dermatophagoides and house dust were highly positive in the senile group like the younger group, while the reaction to spices was more highly positive (43%) than in younger persons. Clinically the recognition of the existence of senile type AD and the introduction of antiallergic therapy for severe eczema of old persons are important.

Age Factors↗
PubMed1989

[Collapsibility of the downstream segment].

With an abrupt interruption of airflow at the mouth during the V-V curve maneuver, the mouth pressure suddenly increased (1st phase), followed by a slower rise (2nd phase). The pleural pressure and alveolar pressure remained constant during this process. The first phase represented the pressure induced by the instantaneous interruption of the airflow itself. Analysis of Vsupramax which occurred just after resumption of the airflow suggested that the choke point was maintained constant during the 2nd phase. Based on the above results, a method was introduced for the determination of the airway compliance (Cb) of the downstream segment. Cb was below 1.5 ml/cmH2O in healthy subjects, and above 1.5 ml/cmH2O in COPD. Cb should be useful for the pathophysiological evaluation of the V-V curve and large airway in various diseases.

Adult↗
PubMed1988

Biochemical study on the brain of the macular mutant mouse as a model of Menkes' kinky hair disease.

The wet weights, contents of DNA, RNA and protein and 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) activities were examined in the cerebrum, brain stem and cerebellum from macular mutant mouse, as a model animal for Menkes' kinky hair disease (MKHD). The DNA, RNA and protein contents in the cerebellum from macular hemizygous males (Ml/y) were affected to a much greater extent than those in the cerebrum and the brain stem. This suggests that the main affected part of the brain in Ml/y mouse is the cerebellum. CNP activities in the Ml/y mouse showed a significant decrease in every part of the brain after day 10. This finding may coincide with the changes in myelination in human MKHD.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1988

Mouth pressure curve on abrupt interruption of airflow during forced expiration.

The mouth pressure curve after abrupt interruption during forced expiratory maneuver was investigated to evaluate the collapsing state of the airway downstream to the choke point. Immediately after the airflow interruption at the mouth by means of the electromagnetic valve, the mouth pressure suddenly increased (1st phase), followed by a slower rise (2nd phase) within about 100 msec until the pressure reaches the alveolar pressure. The pleural and alveolar pressures remained constant during this process. It was evidenced that, from point of view of mean flow, the airflow flowed at a rate of Vmax through the choke point during the second phase. Thus, it is strongly suggested that the choke point remained at the same point during the 2nd phase. From these results, the 2nd phase of the mouth pressure is expected to represent the specific characteristics for the downstream airway.

Forced Expiratory Flow Rates↗
PubMed1988

Airway pressure-volume curve estimated by flow interruption during forced expiration.

The pressure-volume characteristics of the airway downstream to the choke point was estimated with abrupt interruption of airflow at the mouth during forced expiration. The pressure was measured at the mouth and the volume was given by the maximum flow immediately before interruption multiplied by interruption time. The compliance of the airway downstream to the choke point, i.e., a slope of the pressure-volume curve, was 1.04 ml/cmH2O at 50% FVC, and increased in lower lung volumes, in 7 healthy subjects. Whereas, in a case of tracheo-bronchopathia osteochondroplastica, its value decreased markedly.

Airway Resistance↗
PubMed1988

A new method for measuring the pneumotachometer characteristics using a syringe.

A new method for determining the nonlinear characteristics of pneumotachometers was developed. This method consists of a computer algorithm analyzing unsteady flows generated by a syringe. We removed the possible influence of the frequency characteristics of the measuring system by inserting an acoustic low pass filter in the path of gas flow. Two types of Fleisch pneumotachometers were tested. For a given volume of 3 l, the error of measured volume is 12.5% in uncorrected series and 0.2% in the corrected.

Algorithms↗
PubMed1987

Effects of glycyrrhizin and glycyrrhetinic acid on growth and melanogenesis in cultured B16 melanoma cells.

The effects of glycyrrhizin (GL) and its aglycone, glycyrrhetinic acid (GA), on the growth and differentiation of mouse melanoma (B16) cells in culture were studied. GA inhibits the growth of B16 melanoma cells, causes morphological alterations and stimulates melanogenesis. GL also resulted in the same changes but only when the concentration was about 20 times more than that needed for GA. When GA was removed after 84 h of treatment, the growth rate recovered slightly, but the doubling time was about twice that of the control. Cytofluorometric analysis showed that the growth inhibition of GA is the result of inhibition of the transfer from G1 to S phase.

Animals↗