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Biomedical subjects

Y Ohashi

Publications and source records attributed to Y Ohashi.

At least 757 records · Page 42Linked to original sources

Reduction of seizure frequency with clomipramine in patients with complex partial seizures.

Two patients with complex partial seizures who had been refractory to various antiepileptics were treated with clomipramine. The frequency of the seizures was reduced to 0-30% of the original levels. It has been reported that imipramine is effective in absence and minor motor seizures, and its antiepileptic effect is thought to be related to the inhibition of the presynaptic re-uptake of serotonin and norepinephrine. The basic effect of clomipramine is the same as that of imipramine except that the inhibitory action of clomipramine on serotonin re-uptake is 5- to 10-times more potent than that of imipramine. It is implied that clomipramine may be of use in the treatment of partial epilepsies.

Adolescent↗

Risk factors for development of proteinuria in NIDDM analyzed by Poisson regression.

To clarify the time dependency of risk factors for the development of diabetic nephropathy, we applied Poisson regression to the analysis of 7167 person-year data in 1447 patients with non-insulin-dependent diabetes mellitus (NIDDM) who were initially free of proteinuria. Significant predictors were found to be annual mean fasting blood glucose (FBG) level, male gender, duration, and age at diagnosis. Hyperglycemia was more influential, while duration was less in the previous year of development of proteinuria than at the initial visit. When more information during longer-year data was used as average, the contribution of FBG level was enhanced. Current age was less associated than was age at diagnosis. Thus, Poisson regression seems to be useful for the analysis of risk variables in chronic diseases.

Blood Glucose↗

Treatment of full-thickness macular holes with autologous serum.

A total of 28 patients (29 eyes) with stage 2-4 idiopathic full-thickness macular holes were treated with the use of autologous serum. Autologous serum (20-30 microL) was placed over each macular hole followed by injection of 16% perfluoropropane gas. Postoperatively, 28 eyes (97%) had flattening of the macular hole, and the hole could not be detected in 27 eyes (93%). Twenty-two eyes (76%) showed visual acuity improvement by at least two lines or more. Preoperative factors such as good visual acuity, earlier stage, and younger age were correlated with postoperative good visual acuity. These results suggest that autologous serum is beneficial in the treatment of full-thickness macular holes.

Adult↗

Long-term visual recovery after scleral buckling for macula-off retinal detachments.

The authors retrospectively investigated the long-term visual recovery in 32 macular reattached eyes that had been monitored for more than 5 years after surgery. The best corrected visual acuities were better at 5 years postoperatively than at 3 months by two lines or more in 17 eyes (53%). In these 17 eyes, visual acuities continued to improve for up to 10 years after surgery. In the other 15 eyes, the visual acuities remained within one line of the 3-month values. Improvement of the long-term postoperative visual acuity was found to be statistically correlated with younger age, no or mild myopia (>-5 diopters), and shorter duration of macular detachment (< or =30 days). Surgeons should be aware that the visual function of reattached retinas may continue to improve over the long term, especially when these beneficial factors are present.

Adolescent↗

Mucosal pathology of an experimental otitis media with effusion after X-ray irradiation.

Ten guinea pigs were irradiated with 30 Gy of x-radiation. Five were killed on the eighth day after irradiation, and the remainder were killed at the sixteenth day after irradiation. At the time of death, examination was made of the ciliary activity and the fine structure of the middle ear mucosa. Serous effusion was found in each tympanic cavity of all animals. It was shown also that the guinea pig, when irradiated with 30 Gy of x-radiation, exhibits pathologic abnormalities similar to those in humans with otitis media with effusion: degeneration of cilia or ciliated cells and changes in the vascular system (capillary injury and increased capillary permeability). Functional examinations showed that x-ray irradiation has delayed effects on ciliary activity, and the effects are much greater at the sixteenth day than at the eighth day. We speculate that the accumulation of effusion can be, at least partially, a consequence of ciliary dysfunction. The induction of sterile effusion by the use of x-ray irradiation provides a unique animal model for chronic otitis media with effusion of the serous type.

Animals↗

Experimental otitis media with effusion induced by lipopolysaccharide from Klebsiella pneumoniae: mucociliary pathology of the middle ear.

We inoculated 100 micrograms/ml of lipopolysaccharide (LPS) from Klebsiella pneumoniae into the tympanic cavity of guinea pigs and examined the mucociliary pathology in the middle ear. Serous effusion was observed in the tympanic cavity of every animal on the first, third, and seventh day following the procedure, but the volume of the effusion had decreased to 0.2 ml on day 7. By that time, the ciliary activity in the opening to the eustachian tube within the middle ear had recovered to some extent, but in the middle ear distal to the opening no recovery was apparent. Our results show that cilia close to the eustachian tube play a more significant role in middle ear clearance than those in the middle ear distal to the tube. Compared with our previous study using 10 micron/ml of LPS, this study also demonstrates that inoculations with a higher concentration of LPS induces longer-term middle ear effusions.

Animals↗

Ciliary activity on adenoids of patients with otitis media with effusion.

Ciliary activity of the adenoidal surface in patients with otitis media with effusion (OME) was evaluated by a photoelectric method. Three groups of patients were compared: a non-OME group whose members had experienced no episode of OME; a middle ear effusion (MEE)-negative OME group whose members had an episode of recurrent OME but no MEE during the month preceding the operation; and an MEE-positive OME group whose members were experiencing an episode of recurrent OME with MEEs when tissue was taken for examination. To serve as a comparison, the ciliary activity in the central pharynx of normal guinea pigs was evaluated using the same technique. The ciliary activity in all patients was significantly lower than that in normal guinea pigs. No significant difference in ciliary activity was apparent between the non-OME group and the MEE-negative OME group. However, both were significantly higher than the ciliary activity of the MEE-positive OME patients. The following findings are drawn from our data: ciliary activity on the surface of hypertrophic adenoids is depressed, and patients with OME have reduced ciliary activity compared with those who have no otitis media or those who have otitis media without effusion.

Adenoids↗

Current progress in the development of a totally implantable Gyro centrifugal artificial heart.

A totally implantable centrifugal artificial heart has been developed using a miniaturized pivot bearing supported centrifugal pump (Gyro PI pump). The authors report current progress in its development. The Gyro PI-601 has a priming volume of 20 ml, weighs 100 g, has a height of 60 mm, and has a diameter of 65 mm. This pump can provide 8 L/min against 150 mmHg at 2,250 rpm. It is driven by an miniaturized DC brushless motor with the coils fixed in a plastic mold that is waterproof and made of titanium (weight, 204 g; height, 18 mm; diameter, 65 mm). In this centrifugal artificial heart, two Gyro PI pumps are implanted independently to replace cardiac function without resecting the native heart. Its anatomic and surgical feasibility were confirmed experimentally. The Gyro PI-601 was implanted as a right or left ventricular assist device in the preperitoneal space of five calves. All five tests proceeded without any thromboembolic symptoms. One of five tests was extended more than 1 month to confirm the long-term feasibility of the Gyro PI-601 pump system. Based on the satisfactory results of the in vivo tests, the material conversion of the Gyro PI from polycarbonate to titanium alloy (Ti-6A1-4V) was undertaken to improve its biocompatibility for long-term implantation.

Alloys↗

Development of a silicone hollow fiber membrane oxygenator for ECMO application.

A new silicone hollow fiber membrane oxygenator for extracorporeal membrane oxygenation (ECMO) was developed using an ultrathin silicone hollow fiber, with a 300 microm outer diameter and a wall thickness of 50 microm. The hollow fibers were mechanically cross-wound on the flow distributor to achieve equal distribution of blood flow without changing the fiber shape. The housing, made of silicone coated acryl, was 236 mm long with an inner diameter of 60 mm. The surface area was 1.0 m2 for prototype 211, and 1.1 m2 for prototype 209. The silicone fiber length was 150 mm, and the silicone membrane packing density was 43% for prototype 211 and 36% for prototype 209. Prototype 211 has a priming volume of 208 ml, and prototype 209 has a priming volume of 228 ml. The prototype 211 oxygenator demonstrates a gas transfer rate of 120 +/- 5 ml/min (mean +/- SD) for O2 and 67 +/- 12 ml/min for CO2 under 2 L of blood flow and 4 L of O2 gas flow. Prototype 209 produced the same values. The blood side pressure drop was low compared with the silicone sheet oxygenator (Avecor, 1500ECMO). These results showed that this new oxygenator for ECMO had efficiency similar to the silicone sheet oxygenator that has a 50% larger surface area. These results suggest that the new generation oxygenator using an ultrathin silicone hollow fiber possesses sufficient gas transfer performance for long-term extracorporeal lung support.

Carbon Dioxide↗

Stressful life events and smoking were associated with Graves' disease in women, but not in men.

OBJECTIVE: Although psychological stress and smoking have been proposed as contributing factors to Graves' disease, their independent roles in the pathogenesis of this disease have not been determined. We assessed the association between Graves' disease and psychological stress and smoking by using multivariate analysis. METHODS: By a matched case-control method, we investigated the association between Graves' disease and stressful life events, daily hassles, smoking, drinking habits, coping skills, and social support in 228 patients (182 women and 46 men) with newly diagnosed Graves' disease; we used the conditional maximum likelihood method. RESULTS: After data were adjusted for daily hassles, smoking, drinking habits, social support, and coping skills, we found that stressful life events were significantly associated with the risk of Graves' disease in women. The relative risk was 7.7 for women with the highest stress score compared with women with the lowest stress score (95% confidence interval, 2.2 to 27, p for trend < .001). Smoking was also independently associated with the risk of Graves' disease in women. The relative risk for women with the highest number group compared with women with the lowest number group for smoking cigarettes was 5.1 (95% confidence interval, 1.0 to 27; p for trend < .001). These factors were not significantly associated with Graves' disease in men. CONCLUSIONS: Psychological stress and smoking were associated with Graves' disease in women, but not in men.

Adaptation, Psychological↗

Differential pattern of the circadian rhythm of serum melatonin in young and elderly healthy subjects.

The daily profile of serum level of melatonin was studied in 10 young and 13 elderly subjects. All of the subjects were physically and psychiatrically healthy and did not have any clinical symptoms related to rhythm disturbance. Blood samples were taken every 3 h for 1 day and serum melatonin levels were determined by RIA. All except for 1 of the elderly subjects exhibited a clear circadian rhythm of serum melatonin level with a nocturnal peak. In both subject groups, the melatonin rhythm showed significant diurnal variation. There was no significant difference in the total melatonin level per day between young and elderly groups, suggesting that there was no influence of aging on daily total melatonin secretion. However, there was a marked difference in the features of the melatonin rhythm between the two groups, i.e., a rapid decline of the melatonin level from the nocturnal peak in the elderly group, suggesting that the off-set time of melatonin secretion advances with aging. Our findings suggest that the pattern of melatonin rhythm alters significantly without clear clinical symptoms in the process of senescence.

Adult↗

Effects of Staphylococcus aureus on the ciliary activity of the middle ear lining.

Our previous investigation using normal guinea pigs disclosed that, like respiratory mucosa, the middle ear lining has ciliary activity, and that this ciliary activity becomes more active as the location becomes more distal to the eustachian tube. In this experimental study, the effects of Staphylococcus aureus on the middle ear lining was examined from functional and morphological viewpoints. In conclusion, the ciliary activity at the entrance to the eustachian tube and that more distal to the tube present a similar pattern of reaction to S aureus in an in vitro system. On the other hand, the ciliary activity of the middle ear lining displays a varying pattern of reaction according to the locations within the tympanic cavity.

Animals↗

Electron microscopic study of the inner ear following anaphylaxis.

Although very little is known about the role of immunologic responses in disorders of the inner ear, including sensorineural hearing loss, data lending support to the possibility of their involvement have recently been published. The present experimental study was undertaken to obtain a better understanding of the fine structures of the inner ear following systemic immune responses. In guinea pigs sensitized with egg albumin, antigen challenge not only evoked bronchospasms, but also induced some pathologic changes in the inner ear, especially in the stria vascularis. These findings lead to the inference that the inner ear may be affected by systemic immune responses in sensitized animals.

Anaphylaxis↗

House dust mite-specific IgE, IgG1, and IgG4 antibodies in patients with perennial rhinitis.

Serum samples were obtained from patients with house dust mite-sensitive nasal allergies before and 6 months after immunotherapy, and the level of immunoglobulin (Ig)E, IgG1, and IgG4 antibodies in those sera was determined by the enzyme-linked immunosorbent assay. The present data showed that the mite-specific IgG4 antibodies increased in patients who responded well to immunotherapy but not in those who responded poorly. It was suggested from the present study that IgG4 antibodies seem to act as "blocking antibodies" to reduce the allergic reaction in the target organ, and that an increase of allergen-specific IgG4 antibodies following immunotherapy can be of clinical benefit to patients suffering from mite-specific nasal allergy.

Dust↗