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Biomedical subjects

R Kayamori

Publications and source records attributed to R Kayamori.

At least 19 recordsLinked to original sources
PubMed1989

[A fundamental study on the metabolism of glycosylated low-density lipoprotein].

Low-density lipoprotein (LDL) is considered to be one of the accelerating factors in atherosclerosis. Recently, it has been pointed out that nonenzymaticaly glycosylated LDL (Glc.LDL) is increased in the blood of diabetic patients. In this study, the binding ability of Glc.LDL to culturer cells and its clearance rate in New Zealand White rabbits were examined to the purpose of elucidating those metabolism. Human LDL was taken from healthy subjects and prepared by the ultracentrifugation method, then was glycosylated in vitro by adding [D]glucose. The incorporation of covalently bound glucose increased linearly from beginning and get to the plateau after 12 days of incubation. Surface binding of 125I-Glc.LDL to cultured human fibroblasts was low degree compared to that of native 131I-LDL. The clearance rate of 125I-Glc.LDL in rabbits was slower than that of native 131I-LDL. The half-time for Glc.LDL was 85 hours, and for native LDL the time was 10 hours. Finally, Glc.LDL in human plasma was measured by a m-aminophenylboronic acid affinity column. Preliminary data revealed that the Glc.LDL level was 10.6 +/- 3.0% in diabetic patients (n = 21) and 5.25 +/- 1.1% in non-diabetes (n = 18). The relationships between Glc.LDL and glucose in human plasma for all patients (n = 39) showed linearity and the correlation coefficient was about 0.87 (p less than 0.001).

Adult↗
PubMed1989

[Electrophysiological monitoring of the brainstem function in impending brain death--serial changes of blink reflex and brainstem auditory evoked potential].

Serial changes of EEG, BR and BAEP recordings were obtained over a period of two days on two patients who had suffered massive cerebral hemorrhage while their clinical condition evolved from coma with evidence of preserved cerebral and brainstem functions to a state meeting the criteria of brain death. As clinical evidence of deteriorating brainstem function became apparent in case 1, first wave IV and V components of BAEP disappeared while waves I to III were normal. Finally, when clinical criteria of brain death were fulfilled, the BAEP response was restricted to wave I with small amplitude to stimulation of left ear only. These serial changes were likely consistent with gradual dissolution of brainstem function in a rostrocaudal direction. By contrast, in case 2, the BAEP response was restricted to waves I and II and was stationary in the whole process of impending brain death in no association with some preservation of cerebral and brainstem function. The changes of BAEP was not parallel to the progressive deterioration of EEG and BR. After meeting clinical criteria of brain death, complete abolition of waves II and I was sequential in that order, and then Babinski sign besides withdrawal and deep tendon reflexes may revive in the extremities. Monitoring of serial electrophysiological changes is helpful in the course of impending brain death to determine whether revival of Babinski sign is due to recovery of cerebral-brainstem dysfunction or due to establishment of spinal autonomy.

Aged↗
PubMed1988

[Electrophysiological study of congenital facial paralysis].

The common cause of neonatal facial asymmetry is facial nerve paralysis or "asymmetric crying facies syndrome". In the not uncommon later the lower lip, symmetrical at rest, becomes tilted to the so-called normal side when the patient is smiling or crying, as the congenital hypogenesis of sublabial muscles fail to pull down the lower lip in the opposite side. The electrophysiological differentiation between the two diseases has been performed by orbicularis oculi and oris reflexes with mechanically glabellar and supralabial tapping stimulation, respectively, in addition to needle and/or surface EMG recording. In the facial nerve paralysis of the case 1, R1 and R2 were absent in the orbicularis oculi and oris reflexes. EMG activity was completely lacking over the M. orbicularis oculi and oris innervated by facial nerve. On the contrary, the orbicularis oculi and oris reflexes were normal in the asymmetric crying facial of the case 2. EMG activity was absent only in the sublabial muscles including M. depressor anguli oris and/or M. depressor labii inferioris. Furthermore, needle EMG disclosed no spontaneous activity at rest, which was suggestive of no denervation in the sublabial muscles. It was, however, not possible to determine exactly which muscle the needle was inserted, the M. deprossor anguli oris or the M. depressor labii inferioris. The case 3 might be a variant of asymmetric crying facies with hypogenesis of M. orbicularis oris and/or oculi as well as the sublabial muscle, since the latency was normal but the amplitude was significantly attenuated in the components of orbicularis oculi and oris reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis, Differential↗
PubMed1987

Electrophysiological study of chronic intractable shoulder pain.

Electrophysiological criteria for carpal tunnel syndrome (CTS) may be defined by difference of the distal latencies between median and ulnar nerves in the same hand greater than 2 SD from the normal mean. Based on the data in 20 normal subjects (10 men and 10 women), the criteria for abnormality were distal sensory latency (DSL) over 0.9 msec and/or distal motor latency (DML) over 1.4 msec. Of 100 patients (24 men and 76 women) with chronic intractable shoulder pain (CISP) tested, 53 had electrophysiological CTS; 9 (17%) were men and 44 (83%) were women. Thirty-nine (74%) of these patients had bilateral CTS. Twenty of the 100 patients had nocturnal exacerbation (NE). Eighteen (90%) had CTS; one (6%) was a man and 17 (94%) were women. NE does not necessarily reflect the severity of CTS from statistical analysis. Electrophysiological evaluation is essential for middle-aged women with CISP, and nocturnal exacerbation may be pathognomonic for CTS in these patients.

Adult↗
PubMed1987

[Electrodiagnosis in Martin-Gruber anastomosis].

An anomalous median-ulnar nerve communication in the forearm (Martin-Gruber anastomosis) is not rare. Knowledge of this crossover is of crucial importance in the clinical evaluation of nerve injuries of median and ulnar nerves as well as in accurate interpretation of nerve conduction velocity of these nerves especially in association with carpal tunnel syndrome. The aim of this study was to describe a simple electrophysiological method to detect the anomalous communication innervating hypothenar and thenar muscles. A crossover was detected in 83 (14%) of 600 unselected subjects or 116 (9.7%) of 1,200 limbs. The anomaly was bilateral in 33 (40%) of the subjects and unilateral in 50 (60%), thirty-three on the right and seventeen on the left. Since the crossing fibers are likely to supply primarily the 1st dorsal interosseus muscle, recording of this muscle is essential to disclose the anomaly in addition to routine median and ulnar motor studies of hypothenar and thenar muscles. The anomaly may represent a phylogenetic variant.

Adolescent↗
PubMed1984

Topography of somatosensory evoked potentials after stimulation of the median nerve.

We studied topography of major negative-positive peaks, NI, PI, NII, PII and NIII, of scalp recorded somatosensory evoked potentials (SEP) after stimulation of the median nerve. Unlike the diffusely distributed P14, NI, PI and NII recorded from contralateral hemisphere after unilateral stimulation normally showed statistically significant latency increase from frontal (N17, P20, N29) to central (N19, P23, N32) and parietal (N20, P26, N34) electrodes. However, NIII (N60) had considerable inter- and intra-individual variations with no consistent antero-posterior latency shift. In contrast to well localized N19 and N32 peaks at the contralateral central electrode, the N17, P20 and N29 peaks were registered over the bifrontal and ipsilateral central regions as well as in the vertex. The parietal N20 peak was also present at the occipital electrodes bilaterally. In patients with localized cerebral lesions, types of SEP abnormalities varied considerably, presumably reflecting complex somatosensory afferent pathways. A small lesion in posterolateral thalamus may totally eliminate NI, NII and NIII components over both hemispheres, sparing only P14 whereas a sizable lesion in the frontal or parietal lobe may affect only NII or NIII. Capsular lesions spare P14 and frontal N17 but may alter all the subsequent SEP components, or NII or NIII selectively. In some cases, the corresponding peaks at the central and parietal electrodes may be affected independently. The complex relationships between the type of SEP abnormalities and the location of cerebral lesions can best be explained by postulating the presence of multiple, at least partially independent, thalamocortical projections mediating regionally specific somatosensory inputs.

Adult↗
PubMed1984

Brainstem auditory evoked potential and blink reflex in multiple sclerosis.

Brainstem auditory evoked potential (BAEP) and blink reflex (BR) were abnormal in 40% and 26% of 130 patients with MS. Overall, BR was affected in 53% of patients with abnormal BAEP involving I-III and 41% of those involving III-V interval. In 23 patients with unilateral BR involvement, BAEP was affected ipsilaterally in 10, contralaterally in 0 and bilaterally in 8. In 12 patients with bilateral BR abnormalities, BAEP was involved unilaterally in 1 and bilaterally in 8. We conclude: (1) pontine lesions may prolong either I-III or III-V interwave latency of BAEP, and (2) unilateral abnormalities of BAEP tend to implicate the uncrossed auditory pathways.

Adolescent↗
PubMed1983

Short- and long-latency median somatosensory evoked potentials. Findings in patients with localized neurological lesions.

Short- and long-latency somatosensory evoked potentials (SEPs) were elicited by stimulation of the median nerve in 43 patients with neurological disorders. Abnormalities of short-latency peaks, P9, N13, and P14, were seen in patients with lesions of the peripheral nerve, cervical spinal cord, and brain stem, respectively. Subsequent component, N18, was affected in patients with thalamic or hemispheric disease. In some patients with parietal lobe lesions, however, abnormalities were limited to later components, N32 or N63. Analysis of SEPs is helpful in localizing a lesion along the somatosensory pathway, although differentiation between thalamic and other subcortical or cortical involvement may not be possible with the present SEP technique. Both short- and long-latency SEPs should be studied for maximal clinical information. The latter can be most reliably evaluated by simultaneous bilateral stimulation.

Brain Diseases↗
PubMed1979

[A radioimmunoassay for plasma parathyroid hormone (PTH) using N-terminal PTH antiserum (author's transl)].

In order to investigate plasma bioactive PTH, we tried to assay the N-terminal portion of PTH by RIA. The antiserum to PTH was prepared by immunizing rabbits with a bovine 1-34 PTH conjugate BSA. A preparation of labeled PTH was radioiodinated by the chloramine-T or lactoperoxidase method. Labeled PTH was purified by means of adsorption by Quso G-32 powder or a sephadex G-50. The separation of the free and bound labeled hormone was performed by the dextran-coated charcoal method. The assay was carried out as follows: 0.2 ml diluted buffer (0.05 M, pH 8.6, veronal buffer), 0.1 ml standard PTH or sample to be tested, and 0.1 ml anti-PTH serum were mixed. After the first incubation at 4 degrees C for 4 days, 0.1 ml labeled PTH were added. After a second incubation at 4 degrees C for 12 hours, the assay tubes were centrifuged at 2,000 rpm for 30 min and the precipitates were counted. Various hypothalamic, pituitary and thyroid hormones did not interfere with the RIA for PTH. A dose response curve was obtained in a range from 100 pg to 5,000 pg per ml of standard PTH in this assay system. The serum immunoreactive PTH in healthy subjects values less than 290 pg per ml.

Animals↗
PubMed1979

Does somatostatin in each organ act specifically on that particular organ?

Rats with hypercalcemia induced by injection of vitamin D2 had a decreased thyroid somatostatin content, whereas the somatostatin content in their pancreas was almost within the normal range. This suggests that somatostatin in different organs acts specifically on each particular organ as a local hormone or hormone-like substance.

Animals↗
PubMed1978

Clinical studies of "big ACTH": its physico-chemical characteristics.

The big ACTH fractions available from human plasma and pituitary glands and from porcine pituitary glands were physico-chemically characterized by gel filtration, disc electrophoresis and isoelectric separation. In the case of healthy human subjects, big ACTH fractions were isolated by gel filtration from plasma samples taken during states of acute ACTH hypersecretion such as the lysine-8-vasopressin, insulin or metopyrone tests though none of these fractions were isolated from plasma sampled under normal conditions. Even with no stimulation of ACTH secretion, patients with Cushing's disease gave plasma samples that contained an isolable big ACTH fraction, but such a fraction was hardly isolated from plasma taken from patient with Addison's disease. Both human pituitaries and porcine pituitaries contained an isolable big ACTH fraction. By a gel filtration analysis the molecular weight of the big ACTH was estimated to be higher than 20 000. Disc electrophoresis with an acrylamide gel indicated that big ACTH is strongly basic while small ACTH is more acidic than pH 8.3. Isoelectric separation revealed that the isoelectric point of human big ACTH is higher than pH 10.0 while that of small ACTH is about pH 6.8.

Addison Disease↗