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Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 181 records · Page 10Linked to original sources
PubMed1995

Effect of two metal primers on adhesive bonding with type IV gold alloys.

Bond strengths of an adhesive resin bonded to two types of gold alloys were investigated in vitro with two different metal primers. Disk specimens were cast in a type IV gold alloy designed for resin-bonded restorations and in a low-temperature age-hardenable gold alloy. The specimens were primed with either a vinyl-thiol primer or a thiophosphate primer, then bonded with an adhesive resin initiated with tri-n-butyl borane derivative. Both primers effectively enhanced bond between gold alloys and the adhesive. The use of metal primers in conjunction with type IV gold alloys is useful for resin-bonded fixed partial dentures.

Acrylic Resins↗
PubMed1995

Experimental observation of particulate flow along cranial nerves.

The purpose of this study was to investigate the communicative routes via the cranial nerves among the middle ear, the auditory tube, the inner ear, and the subarachnoid space under nearly physiological conditions. Various volumes of Indian ink were slowly injected into the facial nerve trunk of rabbits at the stylomastoid foramen, then serial sections of the heads were observed under the light microscope. This study yielded the following results: (i) Indian ink penetrated into the subarachnoid space through the internal auditory canal and/or the jugular foramen along the nerve sheaths of the VIIth, IXth, and/or Xth cranial nerves. (ii) Indian ink penetrated through the nerve sheaths of the cochlear, superior vestibular, and inferior vestibular nerves to the fundus of the internal auditory canal. (iii) Indian ink reached the scala tympani and the scala vestibuli via the cochlear aqueduct. (iv) Indian ink penetrated to the nerve sheaths of the tensor tympani and/or tensor palati nerves from the subarachnoid space of the trigeminal ganglion. In conclusion, it was shown that certain small particles are able to penetrate from the facial nerve sheath at the entrance of the stylomastoid foramen to the VIIIth, IXth, and Xth nerve trunks, the middle ear, the area around the auditory tube, the inner ear, and the subarachnoid space.

Animals↗
PubMed1995

Effect of hypocalcemia on muscle in disorders of calcium metabolism.

We reported on three hypocalcemic patients with various serum creatine kinase (CK) levels and Ca metabolic disorders. Two patients with moderate hypocalcemia had increased CK levels (hyper-CK-emia), which normalized during treatment for the hypocalcemia; a negative correlation between the Ca and CK levels was observed in both patients. The remaining patient with mild hypocalcemia had a normal CK level. We discuss the effect of hypocalcemia on muscle in our patients as well as previously reported patients. Muscle may respond to hypocalcemia in three stages, namely homeostatic, asymptomatic hyper-CK-emic and myopathic stages.

Adolescent↗
PubMed1995

Radiofrequency catheter ablation for the treatment of common atrial flutter in humans.

Endocardial catheter ablation has been recently been proposed for the treatment of arrhythmias originating in the right atrium. In this study, we used this technique in 5 patients with paroxysmal common atrial flutter and 3 patients with paroxysmal uncommon atrial flutter. Various antiarrhythmic agents had failed to prevent the recurrence of these episodes. In each procedure, we used a large-tip 7 F quadripolar catheter electrode that was introduced via the femoral vein into the lower part of the right atrium. The two distal electrodes were used to record double-spike potentials or fragmented electrograms. A unipolar electrogram recording from a distal electrode of the same catheter was also used to identify local activation. The targets for ablation were sites which showed double-spike potential and fragmented electrogram 40-60 msec earlier than the onset of the F wave. Application of radiofrequency (RF) energy (25-40 watts) (3-17 applications) terminated atrial flutter and prevented reinduction of atrial flutter in the 5 patients with common atrial flutter. However, atrial flutter could not be terminated with the application of RF energy in the 3 patients with uncommon atrial flutter. The sites at which ablation was successful were located inferior or posterior to the coronary sinus ostium between the inferior vena cava and the tricuspid valve annulus, and were characterized by double-spike potentials and fragmented electrograms with activation times > or = 40 msec before the onset of the F wave. This area may represent the exit site from the area of slow conduction, since pacing from this site showed concealed entrainment of the F wave, and a local electrogram to the onset of the F wave coincided with the pacing spike to the onset of the F wave. Follow-up of these 5 patients (19.4 +/- 10.4 weeks) revealed recurrence of the original atrial flutter in 1 patient and a new type of atrial flutter in 1 patient. The other 3 patients have been episode-free, although an antiarrythmic agent was given for the treatment of paroxysmal atrial fibrillation in 2 patients. We conclude that the application of RF energy to the presumed critical area in the atrial flutter reentrant circuit seems to be effective in terminating and preventing common atrial flutter. Long-term follow-up is required for the recurrence of atrial flutter.

Adolescent↗
PubMed1995

Effects of atrioventricular intervals on right atrial monophasic action potential duration during pacing or reciprocating tachycardia.

We evaluated the relationship between changes in the atrioventricular (AV) intervals and right atrial monophasic action potential duration at 90% repolarization (RA-MAPD90) in humans. In 4 patients, RA-MAPD90 was measured during AV reciprocating tachycardia (AVRT, n = 2) or AV node reentrant tachycardia (AVNRT, n = 2) and atrial or ventricular pacing at similar cycle lengths. In 10 patients, RA-MAPD90 was measured during continuous atrioventricular sequential pacing at AV intervals of 0, 50, 100, 150, 200, 250, 300, 350 msec for 90 sec at a cycle length of 333-400 msec. In patients with AVRT, the RA-MAPD90 during tachycardia was shorter than RA-MAPD90 during RA or RV pacing. In patients with AVNRT, RA-MAPD90 during tachycardia was similar or longer than RA-MAPD90 during RA or RV pacing. As the AV interval was increased from 0 msec to 150 msec, the peak right atrial pressure decreased from 8-12 mmHg to 2-3 mmHg. RA-MAPD90 decreased to its minimal value at an AV interval of 150 msec. The maximal difference in the RA-MAPD90 obtained by changing the AV interval was 22.5 +/- 3.0 msec. We conclude that 1) a very short AV or VA interval causes an increase in RA-MAPD90 which correlates with an increase in RA pressure, and 2) RA-MAPD90 during supraventricular tachycardia is different from RA-MAPD90 during atrial or ventricular pacing. Thus, a contraction-excitation feedback mechanism may exist in the human atrium.

Action Potentials↗
PubMed1995

Temporal bone findings in Cogan's syndrome.

We report on the pathological findings in temporal bones taken from a 92-year-old man who had been diagnosed as suffering from Cogan's syndrome before death. Extensive endolymphatic hydrops was observed in the cochlea of the right ear. The saccule showed a collapse following intense dilation. Outpouching of the utricle and crus commune was found and the perilymphatic space of the posterior semicircular canal was occupied by the fibrotic tissue. The left ear showed neither hydrops nor fibrosis. There was absorption of the enchondral bone in both ears, but in the blood vessels there were no pathological changes.

Aged↗
PubMed1995

Epidemiological and clinical characteristics of Menière's disease in Japan.

From 1975 to 1990, nationwide surveys on Menière's disease were performed three times by the Research Committee of Menière's disease (1975-76) and the Research Committee of Peripheral Vestibular Disorders (1982-84 and 1990) in Japan. Nine hundred and fifty-eight definite Menière cases, 520 in the 1st, 230 in the 2nd and 148 in the 3rd survey, were sampled by the members of the Committees. The epidemiological and clinical characteristics of Menière's disease were analyzed and compared with such control cases as other vertiginous patients, ENT patients without vertigo, and healthy subjects. In Menière's disease, the male to female ratio has changed from even to female predominance over the 15 years the study ran. The age distribution at onset peaked in the forties for males and thirties for females. Significant epidemiological results are summarized as follows: Definite Menière's disease has a higher incidence in married persons and in people with a nervous and precise character, whereas the incidence is lower in obese people. Physical and mental fatigue induced the onset of attacks. Menière's disease happened in day time in many cases, especially during the afternoon. As these epidemiological findings were commonly observed in all the surveys, the results are considered to be universal epidemiological characteristics of Menière's disease in Japan. In the same period, regional investigations were performed by Toyama Medical Association and our University. The male to female ratio in Toyama indicated a more significant female predominance than in the nationwide surveys. The prevalence of Menière's disease in Toyama Prefecture has been almost constant in all surveys, about 17/100,000 since 1974.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Epidemiological study of severe cases of Meniére's disease in Japan.

In order to clarify the characteristics of severe cases of Meniére's disease (MD), we analyzed various epidemiological factors such as sex ratio, past history, complication, cause of onset of vertiginous attacks, etc., in a series of 958 patients with definite MD. Data were obtained from the three Japan-wide surveys of MD conducted by the Meniére's Disease Research Committee of Japan (1975-76) and the Vestibular Disorders Research Committee of Japan (1982-84 & 1990). Following the ideas proposed by the members of the Vestibular Disorder Research Committee of Japan, we divided severe cases into three categories according to the following criteria i) bilateral MD cases (BMD), ii) unilateral MD cases with prolonged disabled vertigo (UPDV), iii) unilateral MD cases with profound hearing loss (UPHL). About 40% of the subjects were classified as severe cases (UPDV: 23%; BMD: 9%; UPHL: 6%). The ratio of otitis media in past history was statistically different between severe cases and non-severe patients (p < 0.05), suggesting that otitis media in the past may contribute to the severity of Meniére's disease.

Adolescent↗
PubMed1995

[Ménière's disease in the aged].

Twenty-one patients with Ménière's disease over the age of seventy years were classified into two groups. Group I: Eleven patients who had their first vertiginous attack after the age of sixty-nine (nine males, two females). Group II: Ten patients who had a long history of Ménière's disease and had been followed until the age of 72 to 79 years of age (seven males, three females). In Group I there were repeated attacks of vertigo accompanied by fluctuations in hearing in the low and middle tone range, though not so severe or frequent as in the typical active stage of Ménière's disease in younger patients. Most patients in this group were still working as managers of a company or institution. Other patients had been taking care of a sick spouse for several years. In Group II, the patients rarely experienced severe vertiginous attacks, however, hearing became rapidly impaired in most cases after they reached around 70 years of age. Progression of their hearing impairment was so severe that it was considered beyond the loss of acoustic function attributable to physiological aging. The importance of Ménière's disease among the aged is increasing as a result of the rapid increase in the aged population. Based on long-term observations of Ménière's disease, we have concluded that there are at least two clinically different types of disease in the aged, then especially age of onset and the duration of the disease of the each patient must be heeded.

Adult↗
PubMed1995

[Observation on the structure of the statocysts of decapods].

Light microscopical observation of serial sections of four kinds of decapoda which living in seas around Japan (Ommastrephes sloanei pacificus, Sepia esculenta, Doryteuthis bleekeri, Sepioteuthis lessoniana) was carried out. These specimens were fixed alive with 10% formaldehyde solution diluted with sea water and then dehydrated without decalcification with ethylalcohol diluted with sea water. After embedding in 6% celloidin, the specimens were cut into 30 microns thick and sections were stained with hematoxilineosin. Under light microscopic observation, the maculae, statoconial layers, cristae, cupulae, statoliths, central nervous system and static nerves were well preserved. The statocysts of all four decapod species were similar in shape. Color photographs of horizontal sections of the head, statocysts, processes, gravity recepter systems, angular acceleration receptor systems, statoliths and nerve fibers with the central nervous system of these four decapod species are shown.

Animals↗
PubMed1995

[Analysis of temporal factor affecting hepatic illusion of a rotated disk].

Twenty-four subjects experienced Cormack's illusion by rotating a disk using fingers of both hands with some pauses inserted during the rotation. Variables were durations for rotating a disk and pause. The illusion magnitude was measured just before each pause. The first experiment showed that the illusion magnitude decreased with increasing the pause. The second experiment showed that there was no difference in illusion magnitude between 5- and 20-second conditions of pause for 20-second rotating duration, although the magnitude was smaller for 20-second pause than that for 5-second pause under the condition of 5-second rotating duration. The experiment also showed that the final magnitude did not depend on whether the magnitude was measured every five seconds or only once at the end of the rotation. The results indicate that pause during rotation contributes to recovering from adaptation due to the rotation and that the effect of pause depends on the duration of rotation. The results also indicate that the increasing illusion magnitude with time is not an artifact due to the method of measuring the magnitude.

Adaptation, Psychological↗
PubMed1995

Scanning electron microscopy study of the palatine salivary glands of rabbits.

The structure of the palatine salivary glands of rabbits was studied employing scanning electron microscopic methods. The fractured surface of the palatine salivary glands revealed that they were formed of small lobuli separated by interlobular spaces containing numerous bundles of collagen fibers. The NaOH treated specimens showed the organization of the collagen fibrils in their original location. In the interstitial stroma compartment, the collagen fibrils revealed a complex three-dimensional arrangement forming channel-like structures for supporting nerve fibers, small vessels and capillaries. Single groups of acinar cells were clearly demonstrated, and each acinus was enveloped by a characteristic basal lamina showing a sponge-like structure made up of several interconnected meshes of collagen fibrils. Furthermore, taking advantage of the ODO method and field emission scanning electron microscopy, within the cytoplasm of secretory acinar cells numerous organelles were clearly observed in a three-dimensional way such as Golgi complex lamellae, rough endoplasmic reticulum, mitochondria and secretory granules. All these cytoplasmic components revealed their real and microtopographical arrangement in some areas of the acinar cytoplasm clearly suggesting their direct involvement in energetic as well as secretory activities.

Animals↗
PubMed1995

IL-4 stimulates the growth of chronic myelomonocytic leukemia cells (CMMoL) once leukemic transformation has occurred.

We have investigated the effects of interleukin-4 (IL-4) on the proliferation of chronic myelomonocytic leukemia (CMMoL) cells in the chronic and leukemic transformation phases in vitro. CMMoL cells formed colonies spontaneously in both phases. IL-4 suppressed the spontaneous growth in the chronic phase, but on the other hand, stimulated colony formation in the leukemic transformation phase. Anti-IL-6 antibody inhibited spontaneous colony formation in both phases. CMMoL cells in both phases produced high levels of IL-6, compared with those produced by acute myelogenous leukemia (AML) cells showing myelomonocytic differentiation and normal monocytes. IL-4 suppressed the IL-6 production by CMMoL cells in both phases. None of anti-IL-6, anti-macrophage colony-stimulating factor (M-CSF), anti-granulocyte-macrophage colony-stimulating factor (GM-CSF), anti-tumor necrosis factor-alpha (TNF-alpha) and anti-IL-1-beta antibodies inhibited IL-4-stimulated colony formation. These results suggest that IL-4 directly stimulates the growth of CMMoL cells once leukemic transformation has occurred and that the therapeutic use of IL-4 for CMMoL should be viewed with caution, especially in the leukemic transformation phase.

Aged↗
PubMed1995

[Anesthetic management for bronchofiberscopy and esophageal mannometric study in a patient with CHARGE association].

Bronchofiberscopy and esophageal mannometric study were scheduled for a CHARGE association patient who complained respiratory distress and dysphagea after PDA ligation. We carried out both tracheal intubation and LMA insertion twice. LMA insertion was performed smoothly, but mask holding and tracheal intubation were very difficult. CHARGE association is a rare multiple anomaly, and presents some problems for anesthetic management. Especially, we have to consider the difficult airway management in such a patient.

Abnormalities, Multiple↗
PubMed1995

Functional Rescue of photoreceptors from the damaging effects of constant light by survival-promoting factors in the rat.

PURPOSE: To investigate whether and how survival-promoting agents rescue photoreceptor cell function and morphology from constant light damage, the authors recorded electroretinographic (ERG) responses and examined light micrographs of retinas in those rats given intravitreal injection of midkine (MK) and basic fibroblast growth factor (bFGF) before constant exposure. METHODS: Albino Sprague-Dawley rats were injected with MK, bFGF, or phosphate-buffered saline (PBS) 2 days before the onset of 1 week of constant light. ERG responses were recorded using white flash stimuli with the intensity range of 4 log units, followed by histologic examinations of retinas, including quantitative assessment of the outer nuclear layer thickness as an index of photoreceptor cell loss. RESULTS: ERG responses were barely detectable in uninjected eyes after 1 week of constant light. On the other hand, distinct responses were recordable in eyes injected intravitreally with MK and bFGF, and the degree of ERG rescue in terms of the amplitude of b-wave was approximately 40% to 60% compared with normal eyes. Intravitreally injected PBS showed slight, but noticeable, preservation of ERG responses as well. Histologic examination revealed that MK and bFGF protected photoreceptors from light damage. A good correlation was found between anatomic rescue of photoreceptors as assessed by outer nuclear layer thickness and the functional rescue as defined by the magnitude of ERG responses. CONCLUSIONS: Functional and anatomic rescue of photoreceptors in albino rats from constant light damage is achieved by prior intravitreal injection of MK and bFGF.

Animals↗
PubMed1995

[Study of the interrelation between variation of blood pressure and pulse rate under various respiratory conditions].

By means of non-invasive continuous blood pressure measurement (Finapres method), coefficient of variation for pulse rate (CV-PR) and coefficient of variation for blood pressure (CV-BP) under various respiratory conditions were calculated simultaneously to examine the interrelation between them. The subjects were 148 healthy normal adults and 75 patients with diabetes mellitus (DM). Both coefficients of variation for healthy normal adults showed significantly (p < 0.01) positive correlations: correlation coefficients tended to be greater during deep breathing than that during resting breathing. The case was the same for the ratio of CV-PR to CV-BP (CV-PR/CV-BP): the ratio for deep breathing was approximately 1.0. The ratio showed a significant decrease for DM patients compared with that for healthy normal group. The examination of the interrelation between these coefficients of variation under various respiratory conditions, which reflected the sensitivity of cardiovascular vagal reflex was considered to be also useful for the judgment of the degree of progress of DM-complications.

Adult↗
PubMed1995

[Problems of commercially available heparinized syringes in measurements of blood gases and electrolytes].

We compared the measured values of blood gases and electrolytes by commercially available heparinized syringes (PZ-II, Quick-lite and QS90) with normal and decreased calcium concentrations. With normal calcium concentration, the measured value of [Ca2+] in PZ-II was significantly less than that in Quick-lite and QS90, seemingly due to contained heparin. With hypocalcemia, the measured values of [Ca2+] in Quick-lite and QS90 were significantly greater than those in non-heparinized syringe. The pH and PO2 decreased, and PCO2 increased as time passed. The [Ca2+] was suggested to be more influenced by heparin than by acid-base balance.

Blood Gas Analysis↗