PubMed Health⌕ Search

Biomedical subjects

S Toriyama

Publications and source records attributed to S Toriyama.

54 records · Page 3Linked to original sources
PubMed1988

Dissociation of muscle action potentials and spinal somatosensory evoked potentials after ischemic damage of spinal cord.

In patients undergoing spinal fusion and Cotrel-Dubousset instrumentation we recorded compound muscle action potentials (CMAP) from the lower limb and spinal somatosensory evoked potentials (SSEP) from the caudal epidural space after direct stimulation of rostral spinal cord via epidural electrodes. In three of 30 patients tested, the derotation maneuver altered CMAP but not SSEP. In ten dogs, we observed similar dissociation with decrease or disappearance of CMAP amplitude and unchanged SSEP after ligation of the thoracoabdominal aorta or intercostal arteries at each level. In contrast, both CMAP and SSEP were unchanged by clamping the artery at the lumbar level. This is likely due to the lack of collateral vascular flow at the thoracic cord level, the anterior cord in particular, which is mainly supplied by a single large radicular artery (Adamkiewicz artery). These findings support that the CMAP and SSEP are mediated through two independent pathways located in the anterior and posterior spinal cord, respectively. We postulate that the dissociate alteration of CMAP and SSEP by derotation maneuver is due to greater vulnerability of the anterior cord or motor tract to ischemia caused by the displacement of anterior spinal or radiculomedullary artery. Therefore, the patients requiring major derotation procedure would benefit from CMAP monitoring, which provides more sensitive measure of anterior cord function that the conventional SSEP monitoring.

Action Potentials↗
PubMed1988

[Surgical treatment of malignant bone tumors of the pelvis and proximal femur].

We reviewed 93 cases of malignant bone tumor in the pelvic region in order to evaluate surgical propriety. Surgical intervention gave a better prognosis in patients who had malignant pelvic tumor even when they had a high recurrence rate, in comparison with patients who had only biopsy or palliative treatment. Preoperative evaluation for extension of the lesion is the most critical factor for successful surgical treatment.

Bone Neoplasms↗
PubMed1988

[Surgical treatment of bone and soft tissue tumors in the sacroiliac area--low- and high-grade neoplasms].

Operative treatment of tumors in the sacroiliac area is very difficult for the orthopedic surgeon. We reviewed low- and high-grade neoplasms in the sacrum and part of the ilium. Primary bone tumors were giant cell tumor, chondrosarcoma and others; invading bone tumors were carcinoma, rhabdomyosarcoma and others; soft tissue tumors were liposarcoma, metastasis of extraskeletal chondrosarcoma and others; total, 19 cases. The preoperative treatment performed was embolization, intra-arterial infusion (chemotherapy) and radiation therapy. The surgical approach used were the posterior, posterolateral, anterior and posterior, anterior and lateral combined approach. The transiliac procedure using the posterolateral approach gives better visualization adjacent to the sacroiliac area. The gap between the sacrum and the ilium is bridged by grafting the resected ilium. The anterior and lateral combined approach was used in the resection of large iliac tumors, and the abdominoinguinal approach was selected for large retroperitoneal tumors. The surgical treatment performed ranged from simple to wide excision, including the external iliac vessels or rectum, and also palliative surgery. Reconstructive surgery was done for reconstruction of the pelvic ring, spinal fusion using instrumentation and replacement of artificial vessels. Many complications and functional loss requiring treatment were encountered.

Adolescent↗
PubMed1987

[Phase I study of natural interferon-gamma].

We report a clinical study of toxicity and pharmacokinetics of intravenously administered natural interferon-gamma. Twenty three cases with metastatic cancer were given interferon-gamma at doses of 10 X 10(4)-400 X 10(4) IU in single injection. Another twenty three cases were administered at doses of 5 X 10(4)-50 X 10(4) IU/day every day for thirty days. Side effects associated with natural interferon-gamma administration were qualitatively similar to those previously reported for alpha, and beta interferon treatment. After intravenous injection, interferon-gamma was cleared monoexponentially with a short half-life of 120 minutes from the circulation. One case with disseminated thyroid cancer showed minor response.

Drug Evaluation↗
PubMed1987

Surgical treatment of giant cell tumors of the pelvis.

There are many problems concerning management of giant cell tumors in the pelvis: diagnosis, surgical approach, adequacy of treatment, reconstruction, and prognosis. Of 58 cases of giant cell tumor of bone from 1962 to 1985, five cases arose in the pelvis, two in the ilium, two in the ischium, and one in the pubis. Surgical procedures included en bloc excision in four cases and intralesional excision in one. Reconstruction included sacroiliac fusion in one, iliofemoral fusion in one, and pelvic prosthetic replacement in another. Recurrence and metastasis did not occur in any of the cases. All patients were able to walk without crutches. A good surgical approach isolates major vessels and nerves, and permits excision to prevent recurrence and control bleeding. Reconstructive surgery may be required for treatment of a pelvic giant cell tumor.

Adult↗
PubMed1986

New approach for diagnosis in herniated lumbosacral disc. Dermatomal somatosensory evoked potentials (DSSEPs).

Dermatomally activated somatosensory evoked potentials (DSSEPs) were recorded over the scalp of 50 healthy subjects and 40 patients who later underwent exploration for herniated lumbosacral disc. DSSEPs normally consisted of 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 a 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 the myelogram were misleading in eight patients, showing either false-positive or false-negative results. The DSSEPs were normal in six patients with documented disc protrusion at the level of the L5 or S1 root. The test was also normal in another case with herniation at the level of the S2 root. In this series, DSSEPs accurately predicted the level and degree of lumbosacral root involvement. In addition to myelography and other electrodiagnostic tests, the DSSEPs are valuable non-invasive diagnostic tool for the evaluation of herniated lumbosacral disc.

Adolescent↗
PubMed1980

Regulation of cell wall mycolic acid biosynthesis in acid-fast bacteria. I. Temperature-induced changes in mycolic acid molecular species and related compounds in Mycobacterium phlei.

Molecular species of two major subclasses of mycolic acids from Mycobacterium phlei, alpha-mycolic acids (M1) and dicarboxy mycolic acids (M3), were separated gas-chromatographically and identified mass-spectrometrically. The mycolic acid compositions of extractable and cell wall bound lipids were markedly influenced by growth temperature. Increasing growth temperature from 20 degrees C to 50 degrees C resulted in an increase in longer chain species of both mycolisc acid subclasses with a concomitant decrease in shorter chain homologues. The most abundant molecular species were C76 and C58 of M1 and M3 in the 20 degrees C grown cells, while the 50 degrees C grown cells contained C80 in M1 and C62 in M3, most abundantly. Changes in mycolic acid composition occurred rapidly after growth temperature was raised from 20 degrees C to 50 degrees C with an increase in C62 and a concomitant decrease in C58. Mass fragmentographic analysis revealed that an increase in total carbon numbers of mycolic acids was caused by the elongation of straight chain alkyl unit, without any changes in alpha-branch. Changes in the molecular species composition of secondary alcohols presumably derived from the ester mycolic acids were also observed and an increase in longer species (C20-ol-2) with a concomitant decrease in shorter ones (C18-ol-2) was noted as the temperature rose. An increase in the growth temperature also resulted in a decrease in unsaturated fatty acids in extractable lipids. These observations suggest that mycobacteria alter the molecular species composition of mycolic acid subclasses and phospholipids, in response to growth temperature, to maintain a suitable membrane function.

Cell Wall↗
PubMedDate not supplied

Pathogenesis of idiopathic scoliosis: SEPs in chicken with experimentally induced scoliosis and in patients with idiopathic scoliosis.

We studied somatosensory evoked potentials (SEPs) in 20 chickens with experimentally induced scoliosis after pinealectomy and in 100 patients with idiopathic scoliosis. We also studied 20 chickens without scoliosis and 20 healthy youngsters. In the chickens, SEPs after leg stimulation was significantly delayed in the scoliosis group compared to the controls. In patients, the latency of cortical potential (N37) after stimulation of tibial nerve was longer in the scoliosis group than in the controls. Our findings in both experimental and clinical studies strongly support the hypothesis that idiopathic scoliosis results from dysfunction in the central nervous system. The type of SEPs abnormalities described in idiopathic scoliosis suggest a pathology from the midbrain to the cortex.

Adolescent↗