PubMed Health⌕ Search

Biomedical subjects

M Machida

Publications and source records attributed to M Machida.

At least 145 records · Page 8Linked to original sources
PubMed1985

Spinal cord monitoring. Electrophysiological measures of sensory and motor function during spinal surgery.

Various recording methods were tested in 60 patients who underwent scoliosis surgery to find the most suitable technique for the spinal cord monitoring and to elucidate the neuroanatomic relationship of the evoked potentials recorded by these methods. Responses were recorded from the scalp and spine after stimulation of the tibial nerve or the spinal cord. The potentials from electrodes placed over the muscles and the tibial nerve after stimulation of the spinal cord were also recorded. Epidurally recorded spinal evoked potentials after stimulation of the tibial nerve generally consisted of two major negative peaks, NI and NII, and subsequent multiple waves. NI may be mediated through the spinocerebellar tract, and NII is most likely mediated through the dorsal column. The polyphasic waves are probably conducted through the slower sensory ascending pathways. The potentials recorded from the muscle after spinal cord stimulation may be mediated through the motor tract. Various recording techniques described in this study were mutually complimentary in confirming the results of tests recorded in the technically difficult environment of the operating room. In general, spinal cord stimulation recorded from the scalp or the spine was superior to peripheral nerve stimulation in yielding better defined responses. If the potential recorded from the muscle after stimulation of the spinal cord is indeed mediated through the motor pathway, this would be useful to assess motor function during surgery.

Action Potentials↗
PubMed1984

[Comparative study on the inhibitory effect of glucagon and secretin on the gastroduodenal motility in man].

Manometric study was performed to compare the inhibitory effect of glucagon and secretin on the gastroduodenal motor activity by infused catheter method. The subjects consisted of 3 healthy volunteers and 7 patients with peptic ulcer and other diseases. The following results were obtained. After the intravenous administration of glucagon (1 mg), the motor activity of the stomach and duodenum was inhibited promptly. According to statistic evaluation, the contraction numbers and motility index decreased significantly during 25 minutes compared with the basal values in both stomach and duodenum. After the administration of secretin (100 units), gastric motor activity was markedly inhibited, although duodenal motility increased during 10 minutes due to the initiation of secretin-induced migrating motor complex. The contraction numbers and motility index in stomach decreased significantly during 20 minutes after the administration. The inhibitory effect of glucagon was more remarkable in duodenum than in stomach. On the other hand, secretin was more effective in stomach than in duodenum.

Adult↗
PubMed1984

[New approach for diagnosis and postoperative evaluation in herniated lumbosacral disc].

Dermatomally activated somatosensory evoked potentials (DSSEP's) were recorded over the scalp in 50 healthy subjects and 40 patients who later underwent exploration for herniated lumbosacral discs. The control subjects showed three negative peaks, N40, N56 and N78, and N41, N59 and N82 after bilateral stimulation of L5 and S1 dermatomes, respectively. In the patient group, the first two peaks were often abnormal in the presence of clinical sensory deficit, whereas the third peak tended to remain normal. At surgery, herniated disc was confirmed in all but six patients. The findings in myelogram were misleading in eight patients, showing either false positive or false negative results. The DSSEP's were normal in seven patients with documented disc protrusion at the level of L5 or S1 root. The test was also normal in another case with herniation at the level of S2 root. In this series, DSSEP's was extremely accurate in defining the level and the degree of lumbosacral root involvement. The findings on electrophysiology and myelography are not comparable, but are complementary, the former indicating function and the latter structure. Thus, electrophysiologic studies and myelography were complementary in providing an accurate diagnosis for herniated lumbosacral disc.

Adolescent↗
PubMed1982

Pharmacokinetic evidence for the occurrence of extrahepatic conjugative metabolism of p-nitrophenol in rats.

p-Nitrophenol (PNP), as a model compound for the study of conjugative metabolism, was administered intravenously to rats. PNP and its conjugated metabolites, i.e. PNP-glucuronide (PNP-Glu) and PNP-sulfate (PNP-Sul), were determined in body fluids by reversed-phase high-performance liquid chromatography using ion-pair systems. Linear pharmacokinetics was applicable in the dose range of 1.6 to 8 mg/kg. The metabolic clearance which was obtained from the area under the PNP blood concentration curve (AUCiv) and from the excretion ratio of the total conjugates as PNP-Glu and PNP-Sul was so close to the hepatic blood flow that the PNP conjugation reactions seemed to be limited by the hepatic blood flow, that is the hepatic extraction ratio (EH) was expected to be 1. However, AUCpv, following portal vein administration of PNP (4 mg/kg), was not zero but was significantly different from AUCiv after the same dosing (P less than 0.05). Consequently, comparison between the AUC values from both dosing routes and the excretion ratio of PNP-Glu and PNP-Sul gave and EH of 0.43. Such a difference in EH obtained by the two methods suggested a contribution by extrahepatic conjugative metabolism. It was shown that the intrinsic hepatic clearance obtained, assuming exclusively hepatic conjugative metabolism, was certainly overestimated. Furthermore, the results of the conjugation reaction in tissue homogenates suggested a contribution by extrahepatic glucuronidation.

Animals↗
PubMed1982

Occurrence of uronic acid in lipopolysaccharides of Vibrionaceae.

The occurrence of uronic acid as a sugar constituent of lipopolysaccharides (LPS) in Vibrionaceae was demonstrated for the first time. More than 100 strains were examined. Of five genera constituting Vibrionaceae, i.e., Vibrio, Aeromonas, Plesiomonas, Photobacterium, and Lucibacterium, the latter three contained uronic acid in LPS of all of their constituting members examined, while it was totally lacking in Aeromonas LPS so far tested. Only the members of genus Vibrio were found to be divided into uronic acid-containing and -lacking groups; V. parahaemolyticus, V. alginolyticus, V. fisheri, V. costicola, Beneckea ('Vibrio'), and V. fluvialis belonged to the former, while all four biotypes of V. cholerae regardless of their serotypes, V. vulnificus and V. anguillarum, belonged to the latter group. The uronic acid content of V. parahaemolyticus O1 to O12 LPS ranged from 1.6 to 4.2%. The uronic acid residue released from V. parahaemolyticus O1, O4, O10, and O12 LPS by heating in 5% acetic acid at 100 C for 2 hr was identified as galacturonic acid; in particular, that from O12 LPS was characterized as D-galacturonic acid.

Aeromonas↗
PubMed1982

Far-field somatosensory evoked potentials after stimulation of the tibial nerve.

In 21 normal subjects, far-field somatosensory potentials were recorded from the scalp after stimulation of the tibial nerve at the ankle (tibial SEP). With the use of a knee reference contralateral to the side of stimulation, the tibial SEP consisted of three major positive peaks, P17, P24, and P31, and three additional but inconsistent components, P11, P21, and P27. Presumable generator sources of the tibial SEP are the popliteal fossa for P11, entry to the sacral plexus for P17, the cauda equina for P21, entry to the conus medullaris for P24, the rostral spinal cord for P27, and the brainstem for P31.

Adolescent↗
PubMed1982

Correlation of drug conjugative metabolism rates between in vivo and in vitro: glucuronidation and sulfation of p-nitrophenol as a model compound in rat.

The correspondence of conjugative metabolism rates in vivo and in vitro was studied in rat using p-nitrophenol (PNP) as a model compound. In PNP-glucuronide conjugation, the hepatic intrinsic clearance calculated from Km and Vmax obtained in the isolated liver cells was approximately three times larger than that calculated by the in vivo blood concentration on the basis of the linear pharmacokinetic concepts, but this difference was not considered essential. On the other hand, in PNP-sulfate conjugation, some inhibition in the isolated liver cells, which was not expected in the in vivo blood concentration, was found at more than 5 microM PNP. Such inhibition mechanism could not be elucidated by the inorganic sulfate concentration in the reaction medium. Accordingly, it was suggested that some unknown reaction mechanism still remained to be studied for the applicability of the conjugation rates in the isolated liver cells, especially sulfation rates, to the pharmacokinetic study in vivo.

Animals↗
PubMed1982

[A study of spinal evoked potentials recording from surface electrodes].

With non-invasive method, spinal evoked potentials to the stimulation of the posterior tibial nerve at the ankle were studied in 20 normal subjects. Lumbosacral spinal evoked potentials, with a reference electrode on the contralateral shoulder or ear, demonstrated two well-defined negative peaks. The first peak originated from a traveling wave of depolarization in afferent fibers in the cauda equina, and the second peak originated in the spinal cord. But, with the use of a knee reference contralateral to the side of stimulation, it consisted of only one negative peak, which originated in the cauda equina. These findings suggest that the entire trunk and head are "active" electrophysiologically and not suitable for use as a reference. Furthermore, segmental conduction velocities between S1 and L2, L2 and T10, T10 and C2 are 58.2, 106.7, 62.3 m/sec, respectively. Thus "traveling wave" between L2 and T10 is different from that in other levels. This leads to the assumption that a "generator" may exist in conus medullaris and that it many influence above and below the T12.

Adolescent↗
PubMed1981

[Two cases of natural infection of Angiostrongylus cantonensis in cynomolgus monkeys (Macaca fascicularis) (author's transl)].

Two of 80 cynomolgus monkeys, Macaca fascicularis, imported from Indonesia showed weakness, anorexia, paralysis of extremities and dysstasia. The blood test conducted at the time of autopsy proved that the white blood cell count markedly decreased in both cases and the blood urea nitrogen content increased in Case No. 1. In Case No. 2, a high blood sugar value, a low red blood cell count and a low hematocrit value were recognized. Histologic examinations revealed the presence of fragments of a nematode in the subarachnoid space of the cerebrum, granular layer of the cerebellum and gray matter of the cervical spinal cord. The findings of eosinophilic meningitis, necrosis, foreign body giant cells and cellular infiltration predominantly with eosinophils were also noted there. Morphological features of the nematode found in the tissue sections were identical, in all respects, with those described by predecessors who made morphological observations on the cross sections of Angiostrongylus cantonensis. Immunoelectrophoretic analyses of sera from these monkeys demonstrated the presence of band "a", which has been described to be highly specific to human A. cantonensis infection. Based on the above-mentioned evidences, the parasite fragments found in the histological sections from the monkeys were identified as A. cantonensis. The cases of natural infection reported herein represent the first, to our knowledge, in which migration of A. cantonensis larvae in the central nervous system of monkey was demonstrated. The present observation suggests applicability of simian angiostrongyliasis as a model for infections in man.

Angiostrongylus↗
PubMed1980

[A study of F-wave and cervical evoked action potentials by cutaneous recording (author's transl)].

The measurement of nerve conduction velocity and electro-myography have been used as auxiliary means to diagnose spinal and peripheral neuropathies. But it is quite difficult to present to establish the diagnosis fo the diseases involving the so-called proximal segments, i.e., the root entry zone of the spinal cord, spinal nerve root and plexus, by either of these methods. In the present investigation, therefore, the diagnostic possibility of the F-wave and cervical evoked action potentials was explored for such diseases. The results obtained were as follows: 1) In 50 normal subjects, the average F-wave conduction velocity over the median nerve was 58.5 +/- 2.3 (S.D.) m/sec (wrist to spinal cord); 60.9 +/- 3.0 (S.D.) m/sec (elbow to spinal cord); and the range of the normal value was 54.1--62.8 m/sec and 55.5--66.5 m/sec respectively at a 5% level of significance. 2) The F-wave led out of the abductor pollicis brevis muscle by stimulating the median nerve showed abnormal patterns in cases with a localized lesion in the medullary segment of the C7, C8, Th1, and nerve root. 3) The F-wave is dependent of the efferent nerve fibers; representing their antidromic conduction, or the activation of a few motoneurons with a resulting centrifugal discharge. 4) By observing the F-wave diagnosis can be established for the abnormalities in the conduction of the proximal segment of the peripheral nerve and the anterior root of the spinal cord and the changes in the excitation level of the anterior horn cells. 5) From the cervical evoked action potentials by cutaneous recording, the diagnosis can be established for the abnormalities in the conduction of the proxial segment of the peripheral nerve, spinal posterior horn and posterior cord. 6) When the F-wave and the cervical evoked action potentials by cutaneous recording were applied to clinical cases with disturbances in the spinal cord, nerve root and plexus, peculiar changes in the parameter were characteristically observed in each disease. It was therefore confirmed that these methods are very useful in the diagnosis of functional impairment of the proximal segments of the peripheral nerve, the root entry zone and plexus of the spinal cord, and motoneurons.

Adolescent↗