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Biomedical subjects

M Akino

Publications and source records attributed to M Akino.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Spinal intramedullary tumor with exophytic growth].

We experienced 22 cases of spinal intramedullary tumor, in which 5 cases were accompanied with exophytic growth. We discussed their clinical and radiological features, and therapeutic problems. Concerning the locations of tumors with exophytic growth, the most common site was conus medullaris, accounting for 60% (3 cases). Histopathological findings were astrocytoma in two cases, and in one case, mixed glioma, ependymoma and hemangioblastoma. In neurological observation, the most common initial symptom was back pain and lumbago, suggesting root pain. No neurological features distinguishable from those of extramedullary tumors were presented. In radiological examination, myelography and CT myelography were very helpful for diagnosis. Myelography and CT myelography showed extramedullary mass, shift and deformity of spinal cord that was not serious as compared with the size of extramedullary mass, and showed the portion where the spinal cord was swollen. Good outcomes were obtained in a case with total removal, and two cases with subtotal and partial removal that were managed with additional irradiation and chemotherapy. However recurrence and intracranial seeding made prognosis poor in two cases where total removal was impossible. We thought that postoperative careful follow-up was necessary not only to detect recurrence but also to detect intracranial seeding in the cases of spinal intramedullary tumor with exophytic growth.

Adult↗
PubMed1988

[Multiple neurinoma of the spinal cord: case report].

The patient, a 72-year-old female, was admitted with an 11-year history of progressive dysesthesia in the left leg. Neurological findings on admission revealed weakness in the bilateral legs, hyperreflexia of left leg, hypalgesia and hypesthesia under the Th 8 level, and urinary incontinence. Plain lumber X-ray showed enlargement of the intervertebral foramen of L 1/2. Myelography disclosed block age at the level of Th 9 and filling defect at the level of Th 10/11 and L1/2. CT myelography revealed a cord swelling and partially exophytic tumor from Th 8 to Th 9, another tumor located posterior-laterally at the level of Th 11, and another tumor located extra and intradural at the level of L1/2. Laminectomy was performed from Th 8 to L 3. A tumor of the Th 9 was located intramedullary, another tumor of the Th 11 was located intradural extramedullary, and another tumor of the L1/2 was located in the epidural space (so-called dumb-bell type tumor). These tumors were removed completely except the extra-canal part of L1/2 tumor. Histopathological examination revealed typical Antoni type A schwannoma in all tumors. This case was considered multiple neurinomas of the spine in which tumors were located in three separate anatomical sites, intramedullary, intradural extramedullary, and epidural sites. This patient did not show café-au-lait spot, and neurofibroma in her body. The authors considered the patient might be a case of central neurofibromatosis. The authors stressed that multiple neurinomas of the spine is not rare, so careful study of the whole spine is necessary including its intramedullar space.

Aged↗
PubMed1988

[Radiological diagnosis of chronic spinal cord compressive lesion at thoraco-lumbar junction].

Radiological findings in five cases with chronic spinal cord compressive lesion at thoraco-lumbar junction were reported. Three cases had spondylosis and two cases had ossification of yellow ligament (OYL). The levels of the lesions were T12/L1 in three cases and T11/12 in two cases. Two out of three spondylotic patients had also OYL at the same level. The five cases consisted of three men and two women. The ages ranged from 42 to 60 years old with a mean age of 53 years old. Neurologically, every patient showed flaccid paresis and sensory disturbance of the legs. Two cases had sensory disturbance of stocking type. The intervals from the onset of the symptoms to the final diagnosis were 6 months, 7 years, 8 years, 11 years and 12 years. Myelography showed anterior spinal cord compression by bony spur in spondylotic patients, and posterior compression by OYL in other cases. Myelography in flexion posture disclosed the cord compression by bony spur more clearly in two out of three spondylotic patients. Delayed CT-myelography showed intramedullary filling of contrast material in two cases, which indicated degenerative change or microcavitation due to long term compression of the spinal cord. MRI was taken in three spondylotic patients and could directly show compression of the spinal cord. Difficulty in detecting abnormality at thoraco-lumbar junction on plain roentgenogram, and similarity of the symptoms to peripheral nerve disease often lead to a delay in diagnosis. The significance of dynamic myelography and delayed CT-myelography when dealing with such a lesion was discussed here.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Thermographic findings of syringomyelia].

Thermographic findings in 10 cases of syringomyelia were reported. 7 cases were associated with Arnold-Chiari malformation and 3 cases with spinal adhesive arachnoiditis. The cases included 3 men and 7 women, aged 7 to 56 years (mean age 27.7 years). Comparing the right side of the body with the left side, in 9 cases, thermography demonstrated asymmetric skin temperature of the trunk or extremities. MRI revealed laterality of the syrinx at the level of cervical or lumbo-sacral cord in 9 cases. The side with the lower temperature corresponded with the side of lateralized syrinx in 8 cases. Neurologically, 9 cases had laterality of sensory disturbance and 6 cases had asymmetric motor weakness. The side with the lower temperature also corresponded with the laterality of sensory disturbance in 8 cases, and the side of the motor weakness in 4 cases. Considering these findings, many of the patients with syringomyelia are thought to have asymmetric skin temperature. Intramedullary involvement of sympathetic pathway by the syrinx may cause such a change. As thermography is non-invasive and easy to carry out, it should be a useful method for estimating or even detecting cases of syringomyelia, especially when applied to out-patients.

Adolescent↗
PubMed1988

[Surgical treatment of syringomyelia associated with Chiari malformation].

There is now a controversy about the methods of surgical treatment in syringomyelia associated with Chiari malformation. In this report, the authors emphasize that syringosubarachnoid shunt is effective as a surgical procedure or syringomyelia associated with Chiari malformation. From 1982 to 1986, 17 patients with syringomyelia associated with Chiari malformation were surgically treated. Seventeen patients underwent 22 operative procedures for syringomyelia. Syringosubarachnoid shunt was used in eighteen patients, foramen magnum decompression with syringosubarachnoid shunt in one, foramen magnum decompression with terminal syringostomy in one, terminal syringostomy in one, and ventriculoperitoneal shunt in one. The average postoperative follow up period was 2 years and 3 months, from 4 months to 4 years and 11 months. Thirteen out of 17 patients showed neurological improvement and 3 patients were neurologically unchanged. In one patient, the symptoms deteriorated. Syringosubarachnoid shunt is an effective therapeutic procedure for the patient with syringomyelia associated with Chiari malformation. We think that shunt malfunction by arachnoiditis after operation could be prevented by inserting the shunt tube into the subarachnoid space and closing the arachnoid membrane.

Adolescent↗
PubMed1987

Magnetic resonance imaging of heterotopic gray matter.

Heterotopic gray matter was detected by means of magnetic resonance imaging in a 3-year-old girl with left hemiparesis and atonic seizures. In the inversion recovery sequence, a large area of decreased signal intensity was noted in the right centrum semiovale and differentiation of the right basal ganglia was not clear. We speculated that the brain malformation in our patient occurred at ten weeks conceptional age.

Basal Ganglia↗
PubMed1987

Syphilitic myelitis with its magnetic resonance imaging (MRI) verification and successful treatment.

A 31-year-old man with a 10-day duration of a progressive paraparesis and sensory disturbance was found to have a syphilitic infection which was confirmed by the blood and cerebrospinal fluid (CSF) syphilitic reaction. A discrete and wedge-shaped Gadolinium-DTPA-enhanced lesion on magnetic resonance imaging (MRI) was identified at the level of Th 3/4. The neurologic states and MRI findings improved noticeably after a 16-day course of penicillin with a high dose of prednisolone. Therefore, we want to emphasize the importance and usefulness of MRI in syphilitic myelitis.

Adult↗
PubMed1987

[Intra-operative spinal sonography in spinal intramedullary tumor].

Recently, operative results of intramedullary spinal cord tumors have been greatly improved since the introduction of microsurgery. It is very important to know the precise size and location of the tumor prior to the operation so that we can approach the tumor with a minimum of damage to the spinal cord. However, it is not always possible to demonstrate the precise localization of the tumor preoperatively. In this report, we emphasize that intraoperative spinal sonography is very useful in determining the extent of the tumor and differentiating solid component from cystic component of the tumor. Methods and Materials We performed intraoperative spinal sonography on ten patients with intramedullary spinal cord tumor. This series included three cases of hemangioblastoma, three cases of astrocytoma, two cases of ependymoma, one case of subependymoma, and one case of mixed glioma. Eight out of ten cases were associated with cysts. The intraoperative spinal sonographic examinations were performed after laminectomy. The linear scanning probe of 5 or 7.5 MHz transducer was used. Results 1) Solid components The acoustic pattern of the solid tumor was either hyperechoic or iso-echoic. Six cases (three hemangioblastomas, two ependymomas, and one astrocytoma) were hyperechoic. Other four cases (two astrocytomas, one subependymoma, and one mixed glioma) were iso-echoic. 2) Cystic components The cysts associated with the tumor were anechoic in six out of eight cases, which were confirmed at surgery, and multiple cysts were identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Diagnosis of a cystic lesion in the spinal cord--studies on delayed CT myelography and MRI].

UNLABELLED: The collection of contrast medium within the spinal cord on delayed CT myelography generally indicates the presence of syringomyelia. We report the cases of cystic myelopathy with intramedullary contrast accumulation on delayed CT myelography. The purpose of this report is to compare MRI with delayed CT myelogram and to discuss the pathogenesis of the intramedullary contrast accumulation on delayed CT myelography. METHODS AND MATERIALS: Thirty patients with intramedullary contrast accumulation on delayed CT myelography were studied with High Resolution Computed Tomography (Siemens Somatom II) and Magnetic Resonance Imaging (MRI) (0.15T imager, Toshiba MRT 15A). MRI were routinely obtained in both axial plane and sagittal plane. Short spin-echo sequences (30 msec TE, 500 msec TR) were used. This series included 6 cases of cervical disc disease, 5 cases of Chiari malformation, 4 cases of lipomeningocele, 4 cases of adhesive arachnoiditis, 2 cases of thoracolumbar spondylosis, 2 cases of trauma, one case of spinal arachnoid cyst, one case of spinal epidural cyst, and 5 cases of idiopathic type. RESULTS: 1) In 17 out of the 30 patients (57%), the region corresponding to the region of contrast medium collection, which was visualized on delayed CT myelography, was seen as an area of the low signal intensity on MRI. In 11 cases out of 17, the syrinx cavity was confirmed at surgery. 2) In 13 cases, delayed CT myelogram showed collection of intramedullary contrast medium, but MRI failed to reveal an area of low signal intensity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

A sensitive assay of GTP cyclohydrolase I activity in rat and human tissues using radioimmunoassay of neopterin.

A highly sensitive and simple assay for the activity of GTP cyclohydrolase I (EC 3.5.4.16) was established using a newly developed radioimmunoassay. D-erythro-7,8-Dihydroneopterin triphosphate formed from GTP by GTP cyclohydrolase I was oxidized by iodine and dephosphorylated by alkaline phosphatase to D-erythro-neopterin, and quantified by a radioimmunoassay for D-erythro-neopterin. This method was highly sensitive and required only 0.2 mg of rat liver tissues for the measurement of the activity. It was reproducible and can be applied for the simultaneous assay of many samples. The activity of GTP cyclohydrolase I was measured in several rat tissues. For example, the enzyme activity in rat striatum (n = 5) was 13.7 +/- 1.5 pmol/mg protein per hour (mean +/- SE), and agreed well with those obtained by high-performance liquid chromatography with fluorescence detection. The activity in the autopsy human brains (caudate nucleus) was measured by this new method for the first time. The activity in the caudate nucleus from parkinsonian patients (n = 6) was 0.82 +/- 0.56 pmol/mg protein per hour which was significantly lower than the control value, 4.22 +/- 0.43 pmol/mg protein per hour (n = 10).

Aminohydrolases↗
PubMed1986

Purification and physicochemical properties of NADPH-specific dihydropteridine reductase from bovine and human livers.

A new type of dihydropteridine reductase [EC 1.6.99.10], which is specific for NADPH as the substrate in the reduction of quinonoid-dihydropterin to tetrahydropterin, was purified to homogeneity from bovine liver and human liver. The molecular weight of the enzyme was determined to be 65,000-70,000. The enzyme was composed of two subunits with identical molecular weight of 35,000; the amino terminal residue was determined to be valine. The isoelectric point of the enzyme was 7.05. The physicochemical properties of this enzyme were quite different from those of bovine liver NADH-specific dihydropteridine reductase [EC 1.6.99.7]. NADPH-specific dihydropteridine reductase did not cross-react with an antiserum raised against the NADH-specific dihydropteridine reductase, nor did the latter enzyme react with an antiserum to the former enzyme, indicating that the two enzymes have no common antigenic determinants. NADPH-specific dihydropteridine reductase from human liver was shown to have properties similar to those of the bovine liver enzyme.

Amino Acids↗
PubMed1986

Catalytic properties of NADPH-specific dihydropteridine reductase from bovine liver.

The catalytic properties of a new type of dihydropteridine reductase, NADPH-specific dihydropteridine reductase [EC 1.6.99.10], from bovine liver, were studied and compared with those of the previously characterized enzyme, NADH-specific dihydropteridine reductase [EC 1.6.99.7]. With quinonoid-dihydro-6-methylpterin, approximate Km values of NADPH-specific dihydropteridine reductase for NADPH and NADH were estimated to be 1.4 micron and 2,900 microns, respectively. The Vmax values were 1.34 mumol/min/mg with NADPH and 1.02 mumol/min/mg with NADPH. With NADPH, the Km values of the enzyme for the quinonoid-dihydro forms of 6-methylpterin and biopterin were 1.4 micron and 6.8 microns, respectively. The enzyme was inhibited by its reaction product, NADP+, in a competitive manner, and the inhibition constant was determined to be 3.2 microns. The enzyme was severely inhibited by L-thyroxine and by 2,6-dichlorophenolindophenol.

2,6-Dichloroindophenol↗
PubMed1986

Computed tomography and magnetic resonance imaging of intramedullary spinal cord tumors.

Magnetic resonance imaging (MRI) was found useful in the evaluation and management of patients with intramedullary tumors. Both T1 and T2 weighted images are mandatory for depicting intramedullary pathology and sizable change of the spinal cord. Intratumoral cysts and syrinxes were often associated with tumors and shown as a low signal intensity on the T1 weighted image. Computed tomography (CT) with intravenous iodine showed enhancement of tumor nodules, in all mixed gliomas, ependymomas and hemangioblastomas. Enhanced MRI using gadolinium-DTPA is equal or superior to enhanced CT in localizing intramedullary tumors.

Humans↗
PubMed1986

[Spinal dural AVM--report of three cases].

A new type of spinal AVM is reported. The characteristics are as follows: All the patients are male over 50-years-old. Their symptoms are insiduous and progressive ischemic pattern. All the lesions locate at the thoracic and lumbar levels. Selective intercostal angiography shows a fistulous AVM adjacent to the intervertebral foramen fed by spinal dural branch and drain into tortuous veins on the spinal cord via radiculomedullary vein. No typical hair-pin configuration by radiculomedullary and spinal cord arteries contributes to the AVM. This type of spinal AVM must be distinguished from so-called singled coiled type spinal cord AVM since pathophysiological features presumably are different from each other; the former is "dural" on anatomical basis, whereas the latter is "pial". Embolization should be recommended as a first choice of treatment to spinal dural AVM.

Aged↗
PubMed1985

Dyspropterin, an intermediate formed from dihydroneopterin triphosphate in the biosynthetic pathway of tetrahydrobiopterin.

The structure of dyspropterin, a new name given to an intermediate which is formed from dihydroneopterin triphosphate in the biosynthetic pathway of tetrahydrobiopterin, has been studied. Sepiapterin reductase (EC 1.1.1.153) was found to reduce dyspropterin to tetrahydrobiopterin in the presence of NADPH. Several lines of evidence showing the formation of tetrahydrobiopterin have been presented. Stoichiometric analysis revealed that there is a 1:2 relationship between the production of biopterin and the oxidation of NADPH during the reductase-catalyzed reduction of dyspropterin. The tetrahydrobiopterin production from dyspropterin was enhanced by dihydropteridine reductase (EC 1.6.99.7). Dyspropterin could also serve as a cofactor in phenylalanine hydroxylase (EC 1.14.16.1) system. These results are consistent with the view that dyspropterin is 6-(1,2-dioxopropyl)-5,6,7,8-tetrahydropterin. Based on our findings, the biosynthetic pathway of tetrahydrobiopterin from dihydroneopterin triphosphate has been discussed.

Alcohol Oxidoreductases↗
PubMed1985

Functional prognosis of surgical treatment of craniosynostosis.

Twenty-three cases of craniosynostosis were studied with regard to age at operation, symptoms, operative methods, and long-term results. Long-term results of 20 cases that were followed up for more than 1 year after surgery showed that mental retardation remained in 8 cases; a slight improvement in mental function was observed in only 2 cases. Of the 8 patients with mental retardation, 7 were operated on more than 6 months after birth, 7 showed striking digital impression on skull X-ray films and 5 were suffering from oxycephaly. Of the 8 patients with mental retardation, 5 had suffered from perinatal asphyxia or had seizures during delivery and subsequent past history. From these observations, factors affecting prognosis are: (1) age at operation; (2) the degree and duration of increased intracranial pressure; (3) the extent and degree of suture closures; (4) perinatal asphyxia and seizure disorders.

Child↗