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Biomedical subjects

Y Mikawa

Publications and source records attributed to Y Mikawa.

At least 37 records · Page 2Linked to original sources
PubMed1994

Hypertrophic spinal pachymeningitis.

A patient with idiopathic hypertrophic spinal pachymeningitis (HSP) with predominant involvement of the cervical and thoracic dura is reported. Serial magnetic resonance (MR) images detected isolated thickening and ridges of the dura mater. There has been no report describing the serial changes of MR images in idiopathic HSP. According to a review of the English and Japanese literature on idiopathic HSP, the prognosis of patients with positive inflammatory signs is worse than that of those with no inflammatory signs. Idiopathic HSP is a rarely reported disease that can resemble other disorders associated with dural compression. MR imaging can help to differentiate it from other disorders, and enables the diagnosis of the disease in its early stage. The prognosis of idiopathic HSP with positive inflammatory signs may be worse; the authors stress the significance of early surgical treatment.

Dura Mater↗
PubMed1994

Quadriplegia caused by push-up exercises.

This paper describes a case of a 52-year-old male patient with spinal cord injury caused by doing push-up exercises in the prone position. To our knowledge, no previous report has been published describing a case of spinal cord injury caused by push-up exercise. These days, sport is recommended not only to the young but also to older persons. However, to the older, who inevitably have some degenerative disease, moderation should be recommended.

Cervical Vertebrae↗
PubMed1991

Stress fracture of the first rib in a weightlifter.

An isolated fracture of the first rib is rare. Stress fractures of the first rib have previously been reported in various sports and the mechanism of fractures of the first rib has been well documented. Stress fractures of the first rib have also been reported in laborers involved in heavy lifting. The course is insidious, and identification of the lesion is usually made on the basis of an incidental roentgenogram. No reported case of stress fracture of the first rib in a weightlifter has hitherto been available. This paper describes such a case for the first time.

Adolescent↗
PubMed1990

Performance of wide-pore silica- and polymer-based packing materials in polypeptide separation: effect of pore size and alkyl chain length.

The effects of pore size and alkyl chain length of silica- and polymer-based packing materials in the elution of polypeptides with an acetonitrile gradient in the presence of trifluoroacetic acid were studied. Considerable differences were found in the performance of alkylsilylated phases prepared from various wide-pore silica particles assumed to have 30-50-nm pores. The pore size of such silica gels was found to be the critical factor in determining the efficiency for high-molecular-weight polypeptides. Silica C18 phases having small pore volumes below 20 nm pore diameter showed comparable performances to C4 and C8 phases for polypeptides with molecular weights of up to 80,000, and were more stable. Polymer-based packing materials with adequate pore size provided excellent column efficiencies and recoveries for polypeptides with higher chemical stabilities than silica-based materials.

Acetonitriles↗
PubMed1990

Hemodialysis-associated amyloidosis of bone of beta-2 microglobulin origin.

A case of hemodialysis-associated amyloidosis in a patient who had been on hemodialysis for 10 years is described. Bone lesions were found in the humeral heads, carpal bones, and femoral heads and necks. Specimens obtained from the pathologically fractured left femoral neck revealed amyloid deposits histologically. Immunoperoxidase staining for beta-2 microglobulin was positive in the amyloid at the light-microscopic level. We reconfirmed that bone lesions associated with long-term hemodialysis are manifestations of amyloidosis of beta-2 microglobulin origin. Hemodialysis-associated amyloidosis should be considered in the treatment of long-term hemodialysis patients.

Amyloidosis↗
PubMed1989

Atlanto-axial subluxation in Down's syndrome.

Atlanto-axial subluxation, which was causing symptoms in eight patients with Down's syndrome, was treated by operation. In every case various congenital bony anomalies were found. Marked myelopathy was present in four cases of ossiculum terminale, and mild myelopathy in one with anteroposterior spondyloschisis. Successful posterior arthrodesis was performed from C1 to C2 in six cases, and from the occiput to C2 in the other two patients with anteroposterior spondyloschisis. Excellent bony union and an overall improvement in symptoms was achieved. The follow-up period was from one year to five years and six months. Early surgical stabilization is the treatment of choice in those cases of symptomatic atlanto-axial subluxation in Down's syndrome where there are congenital osseous anomalies and generalised ligamentous laxity, and where the spinal cord is at risk.

Adolescent↗
PubMed1989

Instrumentation surgery for primary tumors of the spine.

We performed instrumentation surgery on ten patients with the following rare primary spinal tumors; three solitary plasmacytomas, an aneurysmal bone cyst, a chordoma, a giant-cell tumor, a hemangioma, a solitary bone cyst, a benign osteoblastoma, and a chondrosarcoma. These tumors were found in the cervical spine (one case), thoracic spine (five cases), lumbar spine (two cases), and sacrum (two cases). The patients consisted of five men and five women, and their average age was 43.1 years. Harrington instrumentation was used in six cases, Zielke instrumentation in two, a combination of both in one case, and a Kirshner wire in one. In two cases, iliolumbar fusion was performed with Harrington instrumentation, after total resection of the sacrum. Average duration of the follow-up period was 5 years. This report describes these rare cases and emphasizes the effectiveness of instrumentation surgery in the reconstruction of the spine after extensive surgery.

Adult↗
PubMed1988

Stress fracture of the body of pubis in a pregnant woman. Case report.

A case with stress fracture of the body of the pubic bone which occurred in a 35-year-old pregnant woman is described. No underlying pathologic process was found and it would seem that the mechanical load acting on the pubic bone to cause stress fracture is brought about by both the muscle imbalance and ligament laxity. In a few weeks after delivery, the fracture showed a complete bony union.

Adult↗
PubMed1988

Intraspinal epidermoid and dermoid cysts. Surgical results of seven cases.

Seven cases of intraspinal inclusion cysts, surgically treated between 1970 and 1984, are reported in this paper. Four were epidermoid cysts and three dermoid. Two cysts were located in the thoracic spine (one dermoid and one epidermoid) and five in the lumbosacral region (three epidermoid and two dermoid). Associated spinal dysraphia was noted in five cases. Congenital dermal sinus was found in two cases, spina bifida cystica in one, spina bifida occulta in one, and diastematomyelia in one case. The average postoperative follow-up period was 5 years. No neurological symptoms were found in the five patients who received early surgical treatment, but for the two patients whose operations were late, there were some residual neurological deficits. Therefore, early and accurate diagnosis and radical surgical extirpation are emphasized.

Adult↗
PubMed1988

Computer graphic analysis of antigenic sites on the insulin molecule.

Antigenic sites on a protein have been predicted by the measurement of hydrophilicity values. We have compared this approach to the use of atomic temp factors to predict the antigenic sites on insulin. These predictions were based upon computer assisted analysis of X-ray crystallography data. The results demonstrate that the hydrophilic sites A6, B19, B23, B24, and B26 are not on the surface of the molecule and therefore are not potential antigenic determinants. Thus, hydrophilicity values alone are not sufficient to predict antigenic sites. In contrast, atomic temp factors were more predictive of antigenicity. These findings may explain why anti-insulin antibodies are less likely to develop against certain hydrophilic sites.

Animals↗
PubMed1987

Surgical treatment of symptomatic atlantoaxial subluxation in Down's syndrome.

Six cases of relatively uncommon symptomatic atlantoaxial subluxation in Down's syndrome were treated surgically. In all cases, various congenital osseous anomalies were found. Marked myelopathy was noted in four cases of ossiculum terminale and mild myelopathy in one case of anteroposterior spondyloschisis. Five cases were treated successfully with posterior arthrodesis of C1 to C2 and one from the occiput to C2. Excellent bony union and overall improvement in the patients' symptoms was achieved, with a follow-up period ranging from 11 months to three years and nine months. In cases of symptomatic atlantoaxial subluxation of Down's syndrome, where the spinal cord is at risk, early surgical stabilization is the treatment of choice.

Adolescent↗
PubMed1986

Elastin in the human intervertebral disk. A histological and biochemical study comparing it with elastin in the human yellow ligament.

The elastic fiber and elastin in the human yellow ligament and intervertebral disk were studied histologically and biochemically. The elastic fiber in the human intervertebral disk, which until now had not been clearly identified microscopically, was observed clearly. We found the distribution of the elastic fiber in the intervertebral disk to be very sparse and irregular, and its diameter was small, being about one-tenth of that found in the yellow ligament. The elastin contents of the yellow ligament and intervertebral disk were 46.7% +/- 0.9% and 1.7% +/- 0.2% respectively (mean +/- SE) of the total dry weight. The amino acid composition of elastin in the yellow ligament is similar to that of other tissue, as reported in the literature; however, that found in the intervertebral disk is significantly different. It would appear, therefore, that the elastin in the intervertebral disk is of a different type from that found elsewhere.

Adolescent↗