Biomedical subjects

K Otomo

Publications and source records attributed to K Otomo.

At least 37 records · Page 2Linked to original sources

PubMed1995

Dichotic listening in patients with partial section of the corpus callosum.

Patients with a complete section of the corpus callosum have been observed to exhibit strong left-ear suppression when different speech stimuli are presented to both ears simultaneously (so-called dichotic listening). Data concerning the locus of corpus callosum damage that causes strong left-ear suppression remains scanty. In the present investigation, a consonant-vowel syllable dichotic listening test was given to five right-handed patients with partial sections of the corpus callosum, which were located using MRI and accurately defined measurement procedures. The following two measurement methods were used: (i) the genu-splenium (G-S) method, in which a lesion was localized in the anteroposterior dimension relative to the total length of the corpus callosum, defined as the distance between the most anterior point of the genu to the most posterior point of the splenium; and (ii) the rostrum-splenium (R-S) method, which takes into account the curvature of the corpus callosum, and in which a lesion was localized relative to the total length of the corpus callosum, defined as the length of the curved line from the tip of the rostrum to the end of the splenium. Results were compared with scores from 50 normal control subjects. Strong left-ear suppression was observed in two patients, who had surgical sections of the posterior 15.5-18.5% of the corpus callosum as measured with the G-S method, or the posterior 20-24% of the corpus callosum as measured with the R-S method. The suppression phenomenon persisted for more than 10 years post-surgery. On the other hand, the remaining three patients, who had lesions anterior to the posterior 17-28% of the corpus callosum as measured with the G-S method or 20-33% as measured with the R-S method exhibited no left-ear extinction. Despite the common assumption that damage to the posterior part of the trunk of the corpus callosum causes strong left-ear suppression, the results from the G-S method indicated that damage to the splenium defined as the posterior one-fifth of the segment between the anterior-most and posterior-most points of the corpus callosum, cause strong left-ear suppression. By the R-S method, results showed that damage to the splenium (the posterior one-fifth of the curvature of the corpus callosum) and possibly the part extending to the most posterior part of the trunk (the posterior one-quarter of the curvature) causes strong left-ear suppression.

Adult↗

PubMed1995

A technique for stable His-bundle recording and pacing: electrophysiological and hemodynamic correlates.

His-bundle electrograms recorded from intracardiac electrode catheters have been a mainstay of basic and clinical electrophysiology. However, consistent His-bundle pacing has not been as readily achieved. In 13 dogs anesthetized with sodium pentobarbital (30 mg/kg), we recorded leads II and aVR as well as the His-bundle electrogram from the aortic root. A deflectable tip multipolar catheter (4 rings, 5 mm apart) was introduced via the right jugular vein into the right ventricle (RV). In 7 dogs, using fluoroscopy, the tip was placed under the tricuspid septal leaflet. In the other 6, after thoracotomy, the same placement was made by palpation through the right atrial wall. Stable His-bundle and right bundle (Rb) branch recordings were made from distal and proximal electrode pairs, respectively. H-V intervals measured 35 +/- 6 ms from the aortic root and 33 +/- 5 ms from under the tricuspid leaflet (P = NS). Rb-V measured 25 +/- 4 ms. Consistent His-bundle pacing was accomplished from the aortic root with an average stimulus intensity of 6 +/- 10 mA and from the tricuspid leaflet at 16 +/- 8 mA (P < 0.05). In 7 anesthetized dogs we compared the hemodynamic effects of A-V sequential pacing at the same heart rates using the His-bundle recording site under the septal leaflet of the tricuspid valve (A-H pacing) or pacing from the RV apex (A-RV pacing). Under normal conditions there was a significant depression of mean blood pressure when A-RV pacing was compared with atrial pacing (AOO); but no difference was found between AOO and A-H pacing.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Atrial inputs as determinants of atrioventricular nodal conduction: re-evaluation and new concepts.

Radiofrequency ablation was combined with standard recording and pacing procedures to determine the role of the perinodal fast pathway (FP) and slow pathway (SP) in atrioventricular (A-V) conduction in normal dog hearts. In 16 anesthetized, open-chest dogs, we recorded atrial (A) electrograms from the high right atrium (HRA), His bundle (Hb) region and coronary sinus (CS) ostium. In 8 dogs, during HRA pacing at a cycle length of 400 ms, FP ablation induced a significant change in A-H interval (61 +/- 12 to 107 +/- 9 ms, p < 0.001) but no change in Wenckebach cycle length (185 +/- 14 to 190 +/- 12 ms, NS). During ventricular pacing (400 ms cycle length) there was a shift in retrograde atrial activation so that Hb (A) delayed more than CS (A). Subsequent SP ablation in this same group of 8 dogs, produced a significant prolongation of antegrade Wenckebach cycle length (190 +/- 10 to 277 +/- 36 ms, p < 0.002) but only one instance of complete A-V block even though both FP and SP were ablated in accordance with clinical criteria. In another group of 8 dogs, a specially designed ablation electrode was inserted into the right atrium and positioned at the level of the fossa ovalis, 10-12 mm superior to the perinodal area. A radiofrequency linear lesion across the interatrial system induced a marked PR interval prolongation due to an intra-atrial rather than A-V nodal delay. The A-H interval was unchanged, and there was no change in antegrade or retrograde Wenckebach cycle length. In contrast, to the findings in both these groups direct damage to the A-V node showed immediate change in the A-H interval and at the same time progression to second degree and complete heart block. Taken together these results suggest that the perinodal FP and SP are composed of transitional cells which possess distinct electrophysiological properties not shared by adjacent atrial tissues or the compact A-V node itself. We conclude that the persistence of A-V conduction, albeit modified, after FP and SP ablation, suggests the existence of multiple atrio A-V nodal inputs whereas retrograde conduction relies mainly on dual exits from the A-V node to the atria.

Animals↗

PubMed1994

Sterol composition in polyene antibiotic-sensitive and resistant strains of Malassezia pachydermatis.

The membrane sterol compositions of ten strains of Malassezia pachydermatis were analysed by gas-liquid chromatography. Six of these were wild-type strains from clinical sources that were sensitive to polyene antibiotics, whereas the other four strains were resistant mutants that had arisen after treatment with N-methyl-N'-nitrosoguanidine or UV radiation. The wild-type strains contained 838.8 to 1291.7 micrograms of sterol per gram of freeze-dried mycelium. The sterols were composed of 79% ergosterol, 19% fecosterol and 2% lichesterol. The mutant strains contained 277.1 to 348.8 micrograms/g of sterols composed of 76% ergosterol and 24% fecosterol.

Chromatography, Thin Layer↗

PubMed1994

The response of atrioventricular junctional tissue to temperature.

To determine the optimal temperature for catheter heat mapping without damaging cardiac tissue, we studied the electrophysiologic and histologic responses of the atrioventricular (AV) conduction system exposed to a specific range of temperatures. In 18 closed-chest dogs, an electrode catheter with a thermistor, tip was positioned transvenously at the AV junction. Radiofrequency current (RFC) was applied in incremental temperature steps until transient 2nd-degree AV block was induced. Catheter tip temperature (CTT) was measured at each step. RFC was immediately discontinued when AV block occurred. AV conduction was evaluated before and 4 weeks after the procedure. Acute transient 2nd-degree AV block was induced in 45 applications, during which the average CTT was 48.7 +/- 2.7 degrees C. In another 40 applications in which 2nd degree AV block was not induced, the average CTT was significantly lower [46.3 +/- 2.5 degrees C] (p < 0.001). Eleven of 16 dogs showed acute 2nd-degree AV block, but had normal AV conduction at 4 weeks (Group A). In the other 5 dogs, 1st-degree AV block was seen at 4 weeks (Group B). The lowest CTTs in Groups A and B were 45 and 49 degrees C, respectively. Histologic findings in 2 dogs from Group A revealed that 10-15% (by area) of the AV node was fibrotic. These findings suggest that the induction of fully reversible AV block can be achieved by titration of RFC, during the application of RFC to the AV junction. In conclusion, RF energy was used to produce a tip temperature of between 45 degrees C and 49 degrees C, which induced reversible and significant interruption of conduction of in tissue in the AV junction, and presumably also in target sites in clinical RF ablation.

Animals↗

PubMed1993

Three cases of bovine extreme tetralogy of Fallot.

Three female Holstein calves having cyanosis of the visible mucous membrane, exercise intolerance and systolic murmur were examined. Extreme Tetralogy of Fallot with ventricular septal defect was confirmed at autopsy. All of the intrapericardial pulmonary arteries were completely absent in two cases. In the other case, the atretic pulmonary trunk, with a bicuspid valve, rose from a very small chamber which was located on the blind-ending muscular infundibulum. There was no connection between the atretic pulmonary trunk and the right ventricle.

Animals↗

PubMed1992

The relation between amniotic fluid surfactant concentration in preterm labour and histological evidence of chorioamnionitis.

Concentration of amniotic fluid disaturated phosphatidylcholine (DSPC), factors related to cervical ripening, and histopathological evidence of chorioamnionitis were studied in 38 patients in preterm labour with intact membranes; all of them delivered spontaneously before 37 weeks. There was no correlation between the amniotic fluid DSPC level and gestational age at the time of amniocentesis. However, a significant inverse correlation was found between the amniotic fluid DSPC level and the interval between the onset of labour and delivery. The amniotic fluid DSPC level in cases with onset-delivery interval of less than 48 h was significantly higher than that in cases with an onset-delivery interval of 48 h or more. The gestational age in the former group was significantly lower than in the latter (28.6 vs 32.0 weeks). The amniotic fluid DSPC level in the patients with chorioamnionitis was significantly higher than that in the patients without chorioamnionitis, although the gestational age did not differ between the two groups. All 3 infants with RDS were associated with cervical incompetence. Patients in preterm labour with chorioamnionitis may be refractory to tocolysis and have higher amniotic fluid surfactant levels.

Adult↗

PubMed1992

The acquisition of unrounded vowels in English.

This study investigated developmental patterns of acquisition of the unrounded American English vowels /i, I, e, e, ae, a/ by following 6 normally developing children from 22 to 30 months of age. The subjects were examined at approximately 22, 26, and 30 months of age. Results showed that, in general, /i/ and /a/ were mastered early and /I/ and /e/ were least accurate throughout the period of the study. Upon inspection of errors, the following three classes of production errors were identified: (a) intertrial production variability, (b) context-sensitive substitutions, and (c) context-free systematic substitution patterns, or articulatory processes. A decrease in production variability and in the occurrence of articulatory processes with age generally coincided with a gradual improvement in accuracy of production. However, substitutions of lower vowels for /I/ were persistent, and the pattern was observed even at 30 months of age. Individual variation was also evident in the production accuracy, the substitution patterns, and the manner of articulatory improvement.

Articulation Disorders↗

PubMed1992

A critical appraisal of neuropsychological correlates of Japanese ideogram (kanji) and phonogram (kana) reading.

Owing to the Japanese language's unique writing system, which consists of phonograms and ideograms, reading impairments of Japanese brain-damaged patients have attracted the interest of many researchers. Past case reports as well as some widely accepted handbooks and textbooks have concluded that a specific aphasia type or lesion site is associated with a particular impairment pattern of phonograms and ideograms in reading. However, the methodology and analytical procedures in previous studies were inadequate for reliable generalizations to be made. First, the test materials were unspecified or inappropriate, or the number of test items was small. Secondly, the conclusions were presented without providing individual performance data to support them. Thirdly, in associating patterns of reading impairment with lesion sites, only single cases were reported. The present investigation was designed to overcome the omissions of previous studies, and examined the ability to read 46 single phonograms and 46 single ideograms aloud in four groups of sufficiently large numbers of patients; namely, seven pure alexics, 23 Broca aphasics, 13 Wernicke aphasics, and seven patients with alexia and agraphia. Ours are the first data to demonstrate unequivocally no consistent linkage between aphasia type and the patterns of impairment of phonogram and ideogram reading. The impairment patterns were not uniform across patients even in the same aphasia group. A majority of the cases in each group showed that phonograms and ideograms were unselectively impaired. However, ideogram reading was more difficult in three cases in the pure alexia and Broca aphasia groups, respectively, and in one case in the Wernicke aphasia group. Phonogram reading was more severely disturbed in four cases among the Broca aphasics and in one case among the patients with alexia with agraphia. An apparent variability of impairment patterns characterized the Broca aphasic group. These dyslexic patterns did not appear to correlate with the site and extent of lesions identified by computerized tomography scans. Past reports linking a particular impairment pattern of phonogram and ideogram reading and a specific lesion site were studies of single cases, and their conclusions seem oversimplified. While sensory and motor dysfunctions can usually be neuroanatomically localized in individuals, impairments of certain high cortical functions, such as the reading of phonograms and ideograms, may not be correlated with damage to definite neuroanatomical structures.

Adult↗

PubMed1992

Otitis externa induced with Malassezia pachydermatis in dogs and the efficacy of pimaricin.

Eight beagles were experimentally inoculated intraotally with Malassezia pachydermatis to induce acute otitis externa. Three or 4 days after the inoculation, the animals showed the symptoms of otitis externa. All ear canals were erythematous and the dogs were shaking their heads. A large number of M. pachydermatis was noticed in exudate taken from every ear canal. Clinical signs of otitis externa were reduced after treatment with 0.1 ml (per canal) of 1% pimaricin suspension twice a day for 3 days. The amount of exudate decreased gradually and 12 of the 16 ear swabs examined, thereafter, were found to be negative for M. pachydermatis within 10 days. No side effects were observed in all the treated cases. These results suggested that M. pachydermatis could induce the canine otitis externa, and that pimaricin is effective agent for M. pachydermatis infection in ear canals.

Animals↗

PubMed1992

Anatomically corrected malposition (ACM) with subpulmonary infundibulum in a calf: clinico-morphologic case report.

A Japanese black calf with cyanosis, tachycardia, tachypnea and systolic murmur died of hypoxemia and cardiac insufficiency on the 38th day after birth. We could not establish the diagnosis during it's life. However, anatomically corrected malposition (ACM) with ventricular septal defect was confirmed at autopsy. There was situs solitus of the viscera and atria with atrio-ventricular discordance and ventriculo-arterial concordance. The ventricles demonstrated l-loop, i.e. on the right-sided ventricle there was a markedly enlarged morphologic left ventricle, and on the left-sided ventricle there was a hypoplastic morphologic right ventricle with a stenotic tricuspid valve and Ebstein-like deformity. The right posterior aorta originated from the left ventricle. The pulmonary artery arose from the left-sided right ventricle via infundibulum. There was a fibrous continuity between the aortic and mitral valve. We considered that this is the first reported case of bovine ACM.

Animals↗

PubMed1991

Relationship between the duration of fetal breathing movements and gestational age and the development of the central nervous system at 25-32 weeks of gestation in normal pregnancy.

In 15 pregnant women with normal pregnancy at 25-32 weeks of gestation, fetal breathing movements (FBM), fetal body movements and fetal heart rate were continuously and simultaneously recorded over a total period of 180 min. The frequency of successive FBM with a duration less than 10 s (apnea period greater than 3 s) showed a significant decrease (p less than 0.01), while the frequency of successive FBM with a duration greater than or equal to 30 s showed a significant increase from 25 to 32 weeks of gestation (p less than 0.001). Strong positive correlations were also demonstrated between the frequency of FBM with a duration of greater than or equal to 30 s and the number of fetal heart rate accelerations per hour, acceleration/fetal body movement ratio, and the value of fetal heart rate long-term variability. These results suggest that the length of the duration of successive FBM represents a useful parameter for the analysis of fetal respiratory patterns, and that a prolongation of the duration of successive FBM of an individual fetus is related to the functional development of the central nervous system.

Central Nervous System↗

PubMed1991

[Intelligence and language of individuals who incurred left hemisphere injury at no later than 3 years of age].

It is generally considered that damage to the brain during infancy and young childhood results in milder or different syndromes than does brain injury incurred during adulthood. However, only several past studies employed CT scans to confirm that lesions are confined to one of the two cerebral hemispheres. We examined intelligence and language skills of 5 cases, which sustained nonprogressive damage exclusively to the left cerebral hemisphere before 1 year of age, and 1 case, which incurred nonprogressive left hemisphere injury at 3 years of age. These cases were tested at 9 to 25 years of age, or 8 to 22 years after inflicting injuries. The following scales and tests, all of which are Japanese versions, were employed: the Wechsler Intelligence Scale for Children-Revised (WISC-R) to measure intelligence of 3 cases at 15 years of age or younger, the Wechsler Adult Intelligence Scale (WAIS) for 3 cases older than 15 years of age, the Western Aphasia Bettery (WAB) to measure language skills, and the shortened version of the Token Test to assess auditory comprehension skills. Upon administration of the tests, we obtained the following results: 1) Although 1 case had a large lesion in the left hemisphere, she exhibited a high IQ of 111, and was adapted well as a college student. The result suggested that large lesions, if incurred at no later than 1 year of age, may affect intelligence to only a little or negligible extent. 2) Verbal IQ generally declines from left hemisphere damage in adults. In all of our subjects, however, verbal IQ was similar to performance IQ.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1990

The distributions of phytohemagglutinin-P and concanavalin A binding sites on equine, bovine and canine peripheral blood lymphocytes.

The distributions of phytohemagglutinin-P (PHA) and concanavalin A (ConA) binding sites were investigated for equine, bovine and canine peripheral blood lymphocytes (PBL). Non-B lymphocytes were collected from each PBL using a fluorescence-activated cell sorter (FACS), and the numbers of PHA and ConA binding sites on their surfaces were counted. Most PHA binding sites on PBL of the three species were shown on the surfaces of non-B lymphocytes. On the other hand, the ConA binding sites on equine and canine PBL existed mainly on the surfaces of non-B lymphocytes, but B lymphocytes of these two species had many ConA binding sites. These results were confirmed by the results of two-parameter fluorescence analysis using FACS. It is, therefore, concluded that the different optimum concentrations of PHA and ConA in PBL blastogenic responses of each animal depended on the different distributions of their binding sites.

Animals↗

PubMed1990

Comparison of amniotic fluid disaturated phosphatidylcholine, phosphatidylglycerol and lecithin/sphingomyelin ratio in predicting the risk of developing neonatal respiratory distress syndrome.

One hundred forty-one amniotic fluid samples were analyzed for disaturated phosphatidylcholine (DSPC), phosphatidylglycerol (PG) and the lecithin/sphingomyelin (L/S) ratio. The L/S ratio was measured by two-dimensional thin layer chromatography. Mature levels (positive) were defined as an L/S ratio of 2:1 or more, a DSPC level of 100 micrograms/ml or more and a detectable level of PG. The DSPC value agreed with the L/S ratio in 114 samples (80.9%). Fourteen of 17 infants with respiratory distress syndrome (RDS) (82.4%) had immature L/S ratios and immature DSPC levels. RDS developed in 16 of 40 (40%) children with immature L/S ratios, and in 15 of 33 (45.5%) children with immature DSPC levels. The true-positive rates of the L/S ratio and DSPC levels were 99.0 and 98.1%, respectively. PG had a low true-negative rate, as only 17 of 67 (25.4%) samples without detectable levels of PG were associated with RDS. However, when PG was present, it had a 100% predictive value of no-RDS. In conclusion, DSPC is nearly equal to the L/S ratio measured by two-dimensional as concerns diagnostic accuracy. PG is useful as an additional index for predicting lung maturation.

Amniotic Fluid↗

PubMed1990

Isolation, characterization, and quantitative analysis of C-reactive protein from horses.

C-reactive protein (CRP) was isolated from equine serum by use of calcium-dependent affinity chromatography conjugated pneumococcal C-polysaccharide, anion exchange chromatography, and gel filtration. It was identified as genuine CRP by its immunochemical cross-reactivity with anti-human CRP, its homology with human CRP in amino acid composition, and its pentameric structure as revealed by electron microscopy. Purified equine CRP had a molecular weight of approximately 118,000 and was composed of 5 identical, nonglycosylated and noncovalently associated subunits with molecular weight of approximately 23,000 each. Equine CRP migrated in the region between beta- and gamma-globulin by results of immunoelectrophoresis, and its isoelectric point was about 7.0. In horses, increased CRP concentration was associated with clinical pneumonitis, enteritis, and arthritis, compared with values obtained in clinically normal horses by use of single radial immunodiffusion method. After IM administration of turpentine oil or castration, serum CRP concentration increased to 6 times higher than baseline values. Results indicate that CRP may be an acute-phase reactant protein in horses.

Animals↗

PubMed1990

Relationship between mitogen receptors in peripheral blood lymphocytes and blastogenic responses to mitogen.

The relationship between the optimum concentration of mitogen which induces lymphocyte blastogenic response and the receptor occupancy by mitogen was investigated. The receptor occupancies which induced maximal blastogenic activity in equine, bovine and canine peripheral blood lymphocytes (PBL) were 31.1 per cent, 26.5 per cent and 38.4 per cent with phytohaemagglutinin-P, and 48.2 per cent, 17.9 per cent and 24.5 per cent with concanavalin A, respectively. The data clearly show that each animal species had its own optimum concentration of mitogen for stimulation of PBL. Optimum concentration for blastogenesis and number of binding sites of each mitogen had a good correlation with each other for all three species.

Animals↗

PubMed1989

Chromosome analysis of canine transmissible sarcoma cells.

The chromosomal banding patterns of canine transmissible sarcoma (CTS) cells were analyzed and compared to those of normal canine cells with four banding techniques. In addition, N-myc and N-ras oncogenes on the chromosomes of the CTS cells were investigated by the in situ hybridization method. The modal chromosome number of the CTS cells was 58:17 metacentrics and 41 acrocentrics. Based on their G- and Q-banding patterns most of the chromosomes of the CTS cells were present in normal cells except for the second largest metacentric chromosomes. It was considered that the metacentric chromosomes of the CTS cells results from Robertsonian translocation of normal chromosomes. The long arm of the second largest metacentric element of the CTS cells was stained negatively by the Q-banding technique. The C-band was found on the long arm of the second largest metacentric element and three pairs of N-bands were recognized in the same region. It was suggested that this amplification of N-bands enhanced tumorigenic properties in the CTS. No N-myc or N-ras oncogenes were detected on chromosomes of the CTS cells by the in situ hybridization method.

Animals↗