Biomedical subjects

S Endo

Publications and source records attributed to S Endo.

At least 613 records · Page 34Linked to original sources

PubMed1986

[Neurinoma of the oculomotor nerve: case report].

A case of solitary neurinoma of oculomotor nerve is reported. A 40-year-old female had a sudden headache with nausea and vomiting in January, 1978. She complained of diplopia and right ptosis two months later and visited a neurosurgical clinic, but radiological examination was told to be normal. Headache and right ptosis diminished, but diplopia continued. She was admitted to our clinic on Aug. 30, 1984, complaining of diplopia and right ptosis which were noticed only when she was tired. On admission, she had no neurological deficits except for right oculomotor nerve palsy. There was no cutaneous manifestation of von Recklinghausen's disease. Plain skull radiogram and angiogram showed normal study. CT scan showed a solitaly enhancing mass in the right prepontine region. On Sept. 22, 1984, a right frontotemporal craniotomy was performed, and the tumor was totally removed by pterional approach. The tumor was located beside the right internal carotid artery and the oculomotor nerve was incorporated in the tumor. The histological diagnosis was Antoni B type neurinoma. The clinical features of fourteen reported cases of neurinoma of the oculomotor nerve in the literature were reviewed.

Adult↗

PubMed1986

Patterns of sleep-wakefulness before and after transmeridian flight in commercial airline pilots.

This study investigated changes in sleep-wake rhythms due to time zone changes. The subjects were 12 commercial airline cockpit crewmembers on active duty who spent their baseline nights in a sleep facility in Tokyo. After flying from Tokyo to San Francisco, they underwent two consecutive nights of sleep polysomnography and daytime sleep latency tests (MSLTs). During the San Francisco layover, slight changes in sleep quality were observed. REM sleep (%) was decreased, while slow wave sleep (%) tended to increase during the major sleeps. Subjective sleep quality assessments also exhibited a decrease in comparison to the baseline values. Daytime sleepiness as measured by MSLTs was generally greater in the latter half of the awake period during layover as compared with baseline. When the subjects were divided into "morning" or "evening" types, the daytime MSLTs of each type showed different patterns. The former displayed a decreasing L-shaped trend, while the latter showed a pronounced W-shaped pattern. These results suggest that further investigation of the individual differences in circadian phase position may be important for understanding the effects of multiple time zone flights.

Adult↗

PubMed1985

Degradation of substance P by the neuroblastoma cells and their membrane.

Cells of the N-18 line of mouse neuroblastoma and their membrane degrade substance P added exogenously. The degradation by the cells and their membrane, examined by high-performance liquid chromatography, is strongly inhibited by EDTA but scarcely inhibited by captopril and phosphoramidon. Gly-Leu-Met-NH2 is the major cleavage product among C-terminal fragments of substance P in both cases. Thus, the degradation of substance P by the neuroblastoma cells and their membrane seems to take place mainly through the hydrolysis between Phe8-Gly9 by EDTA-sensitive protease(s).

Amino Acids↗

PubMed1985

Disturbances of the circadian sleep-wake rhythm after time zone changes.

Studies on the changes in circadian rhythms due to time zone changes were described with emphasis placed on sleep. The results were summarized as follows. Eastward flights; Decrease of total sleep time, or increase of TST, Disturbances of intra-sleep cycles, Increase of slow wave sleep, Decrease of REM sleep in the amount, Prolonged REM sleep latency. Westward flights; Shortened sleep latency, Shortened REM sleep latency, Increase of percentage REM sleep, Unusual temporal distributions of REM sleep periods. Southward flight; No significant change. From all above mentioned it becomes evident that after transmeridian flight sleep rhythm is clearly disturbed. In this time we emphasized the changes in particular sleep stages rather than the overall changes in sleep-wake cycles. The changes in sleep pattern followed by time zone changes, however, are thought to result from a complicated summation of effects, such as sleep deprivation, sleep reversal, naps, shift in sleep onset time, and circadian rhythm alternation. The possible factors about the changes in sleep will be presented by Dr. Endo in the next lecture.

Aerospace Medicine↗

PubMed1985

The possible mechanisms of the disturbed circadian sleep-wake rhythm after time zone changes.

Changes in sleep after eastward flight; To go to bed at 2300 hr in SFO, which corresponds to 1600 hr in TYO, means that a traveller from TYO starts his sleep from evening nap in TYO. In evening naps, Slow Wave Sleep(SWS) is increased and REM sleep is decreased. In the flight from West to East, however, the subjects experienced one night total sleep deprivation. Consequently, it is necessary to do research on naps after total sleep deprivation. REM sleep is clearly increased in the morning and decreased in the evening in spite of one night total sleep deprivation. These findings indicate that the distribution of REM sleep is not affected by total sleep deprivation, but REM sleep has a clear circadian rhythm. By contrast, SWS is increased in the morning, afternoon and evening naps after total sleep deprivation. Thus, SWS is more independent of circadian effects and responsive to the length of prior wakefulness. From the findings mentioned above, it is assumed that the decrease of REM sleep and the increase of SWS in the first part of the sleep in SFO may be caused by effects of one night total sleep deprivation and circadian rhythm of REM sleep. Changes in sleep after westward flight; The sleep after returning home from east and after the flight from TYO to LDN was different from that in baseline nights in TYO, with decreased REM sleep latency, appearance of SOREMs and increased REM sleep. Since the sleep after westward flight corresponds to that in the early morning to forenoon in the place before the flight, it is necessary to investigate the effect of sleep reversal and naps in daytime. In naps after one night total sleep deprivation, morning naps had shortened REM sleep latency, increased REM sleep and frequent SOREMs. From the findings mentioned above, it is suggested that the nocturnal sleep after returning home from east and in LDN may reflect the circadian rhythm of sleep in the place before the start of the flight.

Adult↗

PubMed1985

Experimental studies on myocardial glucose metabolism of rats with 18F-2-fluoro-2-deoxy-D-glucose.

The myocardial uptake of 18F-FDG was investigated under various conditions, and compared with brain and tumor uptake as a function of blood glucose level. The uptake by the heart of normal feeding rats was rapid and remained essentially unchanged up to 2 h after 18F-FDG injection, approximately 3%-4% dose/g tissue. On the other hand, the myocardial uptake of fasted rats was significantly lower than that of control rats throughout the course of the study, and it was about 0.3%-0.4% dose/g tissue. Myocardial uptake of 18F-FDG was relatively constant at glucose levels under about 120 mg/100 ml and increased steeply at higher blood glucose levels. In contrast, brain uptake decreased linearly with increasing levels of blood glucose, revealing a strong negative correlation between brain uptake of 18F-FDG and blood glucose levels. The tumor uptake pattern remained relatively unchanged, irrespective of blood glucose levels. It was revealed that the glucose demands of brain, heart, and tumor were entirely different. After a glucose load, the myocardial uptake of fasted rats increased only slightly from 0.4% to 0.6% dose/g tissue, in spite of transitional hyperglycemia. In contrast, insulin caused myocardial uptake to increase extraordinarily, although it caused a decrease in blood glucose levels.

Animals↗

PubMed1985

Forward-backward tracing tympanometry in the diagnosis of middle ear pressure.

Two tympanograms (TG) were routinely recorded on each ear by changing the pressure in the external auditory meatus (EAM), one in the decreasing (forward tracing: TG-F) followed by the other in the increasing direction (backward tracing: TG-B). Both TG were drawn on the same chart and the peak locations were compared. In a normal ear the TG-F peak tended to be formed in the negative pressure area and that of TG-B in the positive area. In a model whose middle ear pressure (MEP) was adjusted to the atmospheric pressure, the TG-F peak always indicated a negative pressure and that of TG-B a positive pressure value. As long as the same model was used, the magnitude of peak shift was identical irrespective of the middle ear pressure. The magnitude of the peak shift was influenced by the speed of EAM pressure change and a linear increase was observed up to the speed of 70 mmH2O/sec, both in a normal ear and a model. These findings seem to suggest that the peak location of a unidirectionally drawn TG can not be regarded as indicating the precise MEP. A valid MEP can better be estimated by averaging the peak pressure of TG-F and TG-B of forward-backward tracing tympanogram. In ears with pathology considerable variation was noted in the magnitude of the peak shift, so that relying solely on unidirectionally drawn TG could have lead to misdiagnosis in some cases. This was especially true with ears having small perforations covered with granulation or fluid.

Acoustic Impedance Tests↗

PubMed1985

Tympanograms of otitis media with effusion: an experimental study.

A sufficient explanation concerning tympanogram (TG) of otitis media with effusion (OME) has not been reported. The purpose of the present study was to investigate the relationship between the types of TG and actual pathological status of the middle ear system by means of experimentally modified middle ear clefts. In the present experiments, human temporal bones, guinea pigs' bullae and plastic models were used. The results were as follows: (1) Water was gradually poured into the middle ear cleft through the Eustachian tube. When the water level rose above the umbo, the height of TG slightly exceeded that of the original TG. Further addition of water produced M-shaped TG, however, flat TG (type B) was not detected until the water-line nearly reached the aditus. A similar phenomenon was observed in the plastic models when the water level reached the aditus-equivalent-site. (2) Tympanometrically measured middle ear pressure (MEP) was almost equivalent to the actual MEP recorded by a manometer when the tympanic membrane was normal. However, this result could not be duplicated in flaccid or adhesive tympanic membrane cases. (3) A clear reduction in the height of TG in guinea pigs' bullae was observed with decreased air volume. In addition, shallow TG was produced by an occlusion of the aditus of the human temporal bones and of the aditus-equivalent-site of the plastic models. It was demonstrated that the TG pattern depends on the fluid volume and location, air volume of mastoid cavity, intratympanic pressure and eardrum condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Impedance Tests↗

PubMed1985

Short latency somatosensory evoked potentials to peroneal nerve stimulation in normal Japanese children.

Short latency somatosensory evoked potentials (SSEP) were elicited by stimulation of the peroneal nerve in 68 normal children of 39 weeks to 15 years old. In all subjects, three positive potentials (P1, P2 and P3) and one negative potential (N1) were consistently recorded. A further positive potential (P4) after N1 was not always observed. There was no change of wave form with development. P1, P2, P3 and N1 might be generated in subcortical structures; caudal cervical spine, brainstem, thalamus and thalamocortical pathway, respectively. The latency of each peak per one meter body length decreased with age until 5 or 6 years of age. Moreover, the latency between peaks per one meter body length also decreased with age until 5 to 6 years of age. These findings are consistent with the development of SSEP on median nerve stimulation and with the developmental phenomenon of spinal conduction velocity, and might be related to the increase in the diameter and the progressive myelination of nerve fibers.

Adolescent↗

PubMed1985

Probing stability and dynamics of proteins by protease digestion. I: Comparison of protease susceptibility and thermal stability of cytochromes c.

Protease susceptibility of homologous proteins in their native conformations was studied. This work aims to establish a broad and quantitative basis for the utilization of protease digestion to analyze the local stability of native proteins. Using high-performance liquid chromatography (HPLC) the time course of the proteolytic degradation of intact proteins was quantitatively traced. Rapid separation of peptide fragments with HPLC made possible the elucidation of sequential digestion originating from the cleavage at a very few sites which are locally unstable in the protein structure. Using four serine proteases, chymotrypsin, trypsin, elastase and subtilisin BPN', we found some common trends in proteolysis for a group of proteins of the cytochrome c family. By comparing of the proteolysis and thermal denaturation with ten homologous cytochromes c extracted from horse, beef, Candida krusei, Saccharomyces cerevisiae, chicken, tuna, pigeon, rabbit, dog and rat, protease susceptibility was related to locally unfolding states intrinsic to the native conformation.

Animals↗

PubMed1985

Hydrolysis of substance P and its analogs by angiotensin-converting enzyme from rat lung. Characterization of endopeptidase activity of the enzyme.

Hydrolysis of substance P and nine kinds of substance P analogs by angiotensin-converting enzyme highly purified from rat lung was examined by using amino-group fluorometry and high-performance liquid chromatography. The enzyme hydrolyzed substance P and several analogs, notwithstanding that they did not contain free C-terminal residues. The analyses of cleavage products separated by high-performance liquid chromatography indicated that the enzyme hydrolyzed substance P and its analogs mainly at the bond between Phe8-Gly9 and also at another bond, possibly between Gly9-Leu10, to a lesser extent by an endopeptidase action, followed by successive release of dipeptides by a dipeptidyl carboxypeptidase action. The analogs that had D-amino acid residues substituted at the presumed cleavage sites were scarcely hydrolyzed. It was further found that (Pyr6)-fragment (6-11) was hydrolyzed by the enzyme more efficiently than the other fragment-type analogs and was cleaved at a single bond by the endopeptidase activity of the enzyme. Therefore, this fragment was used as a substrate in order to characterized the endopeptidase activity of the enzyme by employing fluorometry. The activity was dependent on chloride ion, and was inhibited by captopril, MK-421, and EDTA. Thus, the endopeptidase activity of the enzyme showed properties similar to those of the dipeptidyl carboxypeptidase activity of the enzyme.

Amino Acid Sequence↗

PubMed1985

Relationship between sleep efficiency and urinary excretion of catecholamines in bed-rested humans.

The relationship between urinary excretion of catecholamines during sleep and sleep disturbance was examined in four healthy subjects who were confined to bed for approximately 1 week under an entrained condition. Polysomnographic recordings were made throughout the period of continuous bed rest. Free epinephrine and norepinephrine excretion were measured. Sleep efficiency, i.e., percentage of total sleep time over an allotted sleep period, was an indicator of sleep disturbance. All subjects showed a negative correlation between sleep efficiency and epinephrine excretion (average correlation coefficient -0.79, p less than 0.004). Norepinephrine excretion correlated negatively with sleep efficiency in only one subject, and the group average correlation coefficient of -0.28 was not significant. Circadian variations were observed in sleep efficiency and catecholamine excretion. Although epinephrine excretion was influenced by psychophysiological stress arising from the experimental conditions of forced bed rest, the correlation between sleep efficiency and epinephrine excretion remained stable and negative. The urinary excretion of epinephrine could be an effective indicator of sleep disturbance.

Adult↗

PubMed1985

Chronobiological comparison of sleep-wake rhythm between chronic schizophrenia and normal control.

Few studies on schizophrenia with respect to the circadian alteration of the sleep-wake rhythm have been reported. We made a comparative study of the sleep-wake rhythm between chronic inpatient schizophrenics with a relatively bed-prone daily life and normal subjects under the conditions of absolute bed-rest to elucidate the chronobiological features of schizophrenia. The sleep-wake rhythm of the schizophrenics differed from that of the normals in two points: A significant difference was observed in the decrease of Stage 4 during their nocturnal sleep compared with the normal subjects, becoming conspicuous with the increasing lapse of time during sleep. The distribution and amount of their REM sleep in the morning were markedly low and the latency of their REM sleep was also prolonged. These facts suggested that the smooth slide of the sleep-wake rhythm was somewhat disturbed in the schizophrenics and that they were, therefore, in a state of hyperarousal despite their bed-prone life.

Adult↗

PubMed1985