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Biomedical subjects

K Kusaka

Publications and source records attributed to K Kusaka.

At least 55 records · Page 3Linked to original sources

Enzymatic properties of dipeptidyl carboxypeptidase from Bacillus pumilus.

Enzymatic properties of dipeptidyl carboxypeptidase (DCP) from Bacillus pumilus were investigated. The enzyme was more active on tri- and tetrapeptides than angiotensin-converting enzyme (ACE) from rabbit lung. The presence of chloride ion is essential for the hydrolysis. The Km value of angiotensin I for the enzyme was 0.119 x 10(-3) M. The enzyme was not inhibited by the mammalian ACE inhibitors lisinopril and enalaprilat. The enzyme is readily inhibited by EDTA but restored by Co2+, Mn2+, and Zn2+. Therefore, it seems to be a zinc-metallo protease.

Amino Acid Sequence↗

Reduction of delayed neuronal death by inhibition of protein synthesis.

Brief forebrain ischemia in rodents causes delayed neuronal death selectively in the CA1 pyramidal cells of hippocampus. Treatment with a reversible protein synthesis inhibitor, anisomycin, significantly reduced the occurrence of delayed neuronal death in the Mongolian gerbil. This result indicates that de novo synthesis of certain protein(s), collectively termed 'killer protein' is required, possibly due to deprivation of nerve growth factor or other trophic factors.

Animals↗

Experimental glycerol myopathy: a histological study.

Histopathological changes induced by the intramuscular injection of glycerol were studied in the muscle fibers of rabbits. Fifteen minutes after the injection of 1 ml of 50% (v/v) glycerol, hypercontraction of fibers, disruption of the plasma membrane, and invasion of lanthanum into the sarcoplasm were observed. Between 12 and 24 h after the injection, more extensive pathological changes were seen which included: variation in fiber size; degeneration and necrosis of muscle fibers; hypercontraction of fibers by light microscopy; disruption of the plasma membrane by electron microscopy; vacuolar changes; hypercontraction of myofibrils, and selective loss of Z-bands. Between 7 and 14 days after glycerol injection, extensive regenerative changes were seen. The degenerative changes were similar to those seen in muscle in Duchenne muscular dystrophy, suggesting that a similar mechanism may be involved in the two conditions, so that experimental glycerol myopathy could be a good model for pathophysiological studies on Duchenne muscular dystrophy.

Acid Phosphatase↗

Cauda equina neurinoma associated with normal pressure hydrocephalus--case report.

A 45-year-old male was hospitalized because of gait disturbance, urinary incontinence, and memory disturbance. A computed tomographic (CT) scan revealed dilatation of the cerebral ventricles, and a metrizamide CT scan showed reflux into all ventricles. Cerebrospinal fluid obtained at the time of metrizamide CT was highly xanthochromic. Myelograms demonstrated a tumor between the inferior portion of the fifth lumbar vertebra and that of the second sacral vertebra. After removal of a spinal tumor involving nerve fibers at the cauda equina, his symptoms disappeared and the spinal fluid protein normalized. Three months after surgery, a CT scan revealed reduction of cerebral ventricular size. There are 10 reported cases of spinal tumors resulting in normal pressure hydrocephalus. All these and present cases involved protein in the spinal fluid, which might have been the cause of the hydrocephalus.

Cauda Equina↗

High-performance liquid chromatography of carthamin, safflor yellow A and a precursor of carthamin. Application to the investigation of an unknown red pigment produced in cultured cells of safflower.

A reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyse and purify carthamin, safflor yellow A (safflomin-A) and the yellow precursor of carthamin. A red pigment similar to carthamin was extracted from cell suspension cultures of safflower (Carthamus tinctorius L.) as an application of biotechnology. The RP-HPLC method was used to characterize the unknown red pigment. Various spectroscopic methods were used to characterize purified carthamin and the purified unknown pigment. Based on these spectral observations, it was concluded that the unknown red pigment produced in cultured cells of safflower differed from carthamin, although the unknown pigment might be a glycoside. From other observations, the possibility of anthocyanins and carotenoids were also discounted. It was assumed that the cultured cells lacked the biosynthetic pathway of the yellow precursor of carthamin, although they possessed the activity of the enzyme mediating the synthesis of carthamin from the yellow precursor.

Cells, Cultured↗

[Report of a case of intraosseous meningioma].

Cases of intraosseous meningioma appear to be very rare. In the present paper, we report such a case and discuss its etiological histogenesis on the basis of a review of 26 cases previously reported. A 71-year-old female was admitted to our department because of a painless mass in the right parietal region. Neurological findings were normal. Plain skull radiograph showed a 6 X 5-cm osteolytic lesion in the right fronto-parietal bone. CT scan demonstrated this lesion as a mass showing homogeneous enhancement with contrast medium. A right common carotid angiogram showed an avascular area in the parietal region and no tumor stain. The tumor, which was partly attached to the underlying dura, was totally removed surgically, and the postoperative course was uneventful. Histological examination of the specimen revealed fibroblastic meningioma, which was limited only to the outer membrane of the dura. The inner membrane was intact and free of tumor invasion. The histogenesis of intraosseous meningioma is still controversial but the following theories seem to be widely accepted: (1) The tumor arises from a part of the dura which has become trapped in a suture during embryological development. (2) The tumor arises from a part of the dura which has become trapped in a suture due to pressure on the head during delivery. (3) The tumor arises from a part of the dura which has become trapped in the bone due to trauma. (4) The dura which has become trapped in a suture during embryological development may undergo neoplastic change following traumatic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

[Primary intracranial malignant germ cell tumor associated with abnormal high value of alpha-fetoprotein and human chorionic gonadotropin].

A case of primary suprasellar germ cell tumor that produced alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in a 8-year-old boy is reported. Partial removal of tumor and combination chemotherapy using cisplatin, vincristine, and bleomycin (modified PVB therapy) resulted in an almost definite regression of the tumor and improvement from clinical symptoms in this case. After the chemotherapy the concentrations of both serum AFP and serum HCG decreased to normal levels as well. Moreover by the immunoperoxidase method AFP, HCG, and placental alkaline phosphatase were found in this particular tumor tissue. In reviewing previous reports the immunohistochemical demonstration of three tumor markers in a single germ cell tumor is seemed to be extremely rare.

Antineoplastic Combined Chemotherapy Protocols↗

Autosomal recessive distal muscular dystrophy as a new type of progressive muscular dystrophy. Seventeen cases in eight families including an autopsied case.

A new type of progressive muscular dystrophy, autosomal recessive distal muscular dystrophy, is described, based on observations on 17 cases (8 males and 9 females) in 8 families, including an autopsied case. The disease developed in young adults. Muscle weakness and atrophy were most marked in the distal parts of the legs, especially in the gastrocnemius and soleus muscles, and then spread to the thighs and gluteal muscles. Early impairment of standing on tip-toe with retention of the ability to stand on the heels was conspicuous. Difficulty in climbing stairs, standing up and walking subsequently appeared, but rarely progressed to confinement to bed. The forearms became mildly atrophic, with decrease in grip strength, but the small hand muscles were spared. The EMG showed myopathic changes and nerve conduction was normal. Serum creatine kinase activity was characteristically increased up to 100-fold in the early stages of the disease. It was also markedly increased in subjects in the preclinical stage and mildly in some heterozygotes. Muscle biopsies revealed myopathic changes with severe segmental necrosis accompanied by regeneration. The changes were similar to those of Duchenne muscular dystrophy. An autopsied case, aged 68 years, showed generalized muscle abnormalities with a distal predominance. The muscles in the lower legs, especially those of the calves, were severely affected. No lesions were found in the brain, spinal cord or peripheral nerves.

Adolescent↗

[Intracranial lipoma of the temporal lobe--report of a case and review of the literature].

A 52-year-old female was admitted to our clinic with chief complaint of headache since 2 months ago. Plain computed tomography (CT) revealed low density mass in her right temporal lobe beneath the sylvian fissure with mean Hounsfield number of -52. On admission, no neurological deficit was found. This low density mass had no enhancement region. No abnormal finding was seen in plain skull roentgenogram and right carotid angiography. No epileptic pattern was found electroencephalographically. Right fronto-temporal craniotomy and total removal of tumor was performed to confirm the histological nature of this tumor. The tumor was elastic soft with yellowish color and totally removed. Histological examination revieled typical fatty cells and many capillaries. Her postoperative course was uneventful and was discharged with no neurological deficit. Intracranial lipoma is one of rare brain tumors with incidence of 0.03% or 0.046% in all brain tumor. These tumors are most frequently located in the midline structure, especially in the corpus callosum. After introduction of CT scan, however, lipomas of the extraaxial locations are also reported. From review of literature, location of the lipomas may be divided into 2 groups: the one is located in the midline or paramedian structures of the brain and the other is the extraaxial region such as the sylvian fissure or the cerebellopontine angle. The former group is often associated with anomalies of the central nervous system related to dysraphism. However, the latter group is seemed to have rare association with dysraphism.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗

[Recurrence of cerebral aneurysm after neck clipping--report of a case and review of literature].

A case of recurrent cerebral aneurysm after complete neck clipping is reported. A 38-year-old man was admitted to our service 14 days after attack of subarachnoid hemorrhage. On admission, ruptured left middle cerebral artery aneurysm with intercerebral hematoma and non-ruptured right anterior cerebral artery aneurysm were revealed by radiological examinations. Neck clipping was successfully performed to both of aneurysm and aneurysm was completely disappeard in the postoperative angiographical study. Postoperative course was also uneventful and he was discharged with slight right hemiparesis and motor aphasia. Thirteen months after the neck clipping, however, he was readmitted to our hospital with attack of subarachnoid hemorrhage. After admission, a new aneurysm was noted just under the clip at the right anterior cerebral artery. Neck clipping against this aneurysm was performed by reopening the craniotomy. For his postoperative normal pressure hydrocephalus, ventriculoperitoneal shunt was performed at one month after neck clipping. Postoperative course was uneventful and discharged. From review of literature, it was presumed that hemodynamic stress in the site of aneurysm and injury of arterial wall by the clip may be two major factors as a cause of recurrent aneurysm formation. In our case, possibility of the latter cause was suggested.

Adult↗

Histological changes of muscle in a patient with pyruvate dehydrogenase deficiency.

Histological changes of muscle from a 17-month-old boy with pyruvate dehydrogenase deficiency are presented. The patient had muscle hypotonia, mental retardation, seizures, lactic acidosis and hyperalaninemia. Deficient activity of the pyruvate dehydrogenase complex was found in his platelets (about 25% of normal) and of pyruvate dehydrogenase in his biopsied muscle (about 5% of normal). A muscle biopsy specimen showed an increased proportion of type IIC fibers (24%), fiber-type grouping and lipid droplet accumulation.

Adenosine Triphosphatases↗

The presence of myoglobin in human thyroid tissue.

In the present study we sought to determine the presence of myoglobin in human thyroid tissue. When reacted with antihuman myoglobin antibody on the Ouchterlony plate, homogenates of human thyroid tissue formed a precipitation line. When the human thyroid extract was included in human myoglobin RIA, the dilution curve of thyroid extract was parallel to the standard curve of myoglobin. When the myoglobin immunoreactivity in thyroid extract was fractionated with Sephadex G 75 column, the immunoreactivity was eluted in a peak identical with authentic myoglobin. The position of the peak was different from that of thyroglobulin. Myoglobin concentration in thyroid tissue was estimated to be 0.7-110 mg/g wet wt, being about 1/6000 to 1/40 of that in skeletal muscle. Histochemical studies demonstrated the presence of myoglobin immunoreactivity in thyroid tissue, especially in the apical border of thyroid epithelial cells, implying a functional role in iodinating process or exocytotic-endocytotic process.

Adolescent↗