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Biomedical subjects

M Konagaya

Publications and source records attributed to M Konagaya.

At least 55 records · Page 3Linked to original sources
PubMed1990

Neural control of glutamine synthetase activity in rat skeletal muscles.

The mechanism of glutamine synthetase induction in rat skeletal muscle after denervation or limb immobilization was investigated. Adult male rats were subjected to midthigh section of the sciatic nerve. At 1, 2, and 5 h and 1, 2, and 7 days after denervation, rats were killed and denervated, and contralateral control soleus and plantaris muscles were excised, weighted, homogenized, and assayed for glutamine synthetase. Glutamine synthetase activity increased approximately twofold 1 h after denervation in both muscles. By 7 days postdenervation enzyme activity had increased to three times the control level in plantaris muscle and to four times the control level in soleus muscle. Increased enzyme activity after nerve section was associated with increased maximum velocity with no change in apparent Michaelis constant. Immunotitration with an antiglutamine synthetase antibody suggested that denervation caused an increase in the number of glutamine synthetase molecules in muscle. However, Northern-blot analysis revealed no increase in the steady-state level of glutamine synthetase mRNA after denervation. A mixing experiment failed to yield evidence for the presence of a soluble factor involved in regulating the activity of glutamine synthetase in denervated muscle. A combination of denervation and dexamethasone injections resulted in additive increases in glutamine synthetase. Thus the mechanism underlying increased glutamine synthetase after denervation appears to be posttranscriptional and is distinct from that of the glucocorticoid-mediated glutamine synthetase induction previously described by us.

Animals↗
PubMed1990

[Pentose phosphate pathway in neuromuscular diseases--evaluation of muscular glucose 6-phosphate dehydrogenase activity and RNA content].

There have been several reports concerning elevated glucose 6 phosphate dehydrogenase (G6PDH), the rate-limiting enzyme of pentose phosphate pathway (PPP), in experimental muscle disturbances. PPP produces ribose, a substrate of RNA, and NADPH which is a cofactor of fatty acid synthesis. PPP also has a role of by-path pathway of glycolysis. Then, we evaluated G6PDH activity and RNA content in biopsied quadriceps muscle. The subjects were muscles from 23 neurogenic amyotrophy, 54 myopathy including 19 progressive muscular dystrophy (PMD), and 10 controls whose muscle was obtained at orthopedic surgery. Neurogenic amyotrophy consisted of 12 amyotrophic lateral sclerosis (ALS), 4 spinal muscular atrophy and 7 peripheral nerve disorders. Myopathy were 3 Duchenne dystrophy, 2 congenital muscular dystrophy, 8 limb-girdle type dystrophy, 6 facio-scapular +-humeral muscular dystrophy, 6 myotonic dystrophy, 6 mitochondrial myopathy, 5 endocrinological myopathy, 3 hypokalemic myopathy, 8 polymyositis and 4 other inflammatory myopathy. The assays of G6PDH and RNA were performed after Glock's and Fleck's methods, respectively. The control values were 3.6 +/- 0.8 nmol formed NADPH/mg protein/min (M +/- SD) in G6PDH and 0.69 +/- 0.17 micrograms/mg non-collagen protein in RNA. Most cases of PMD, as well as some cases of ALS, hyperthyroidism, mitochondria hypokalemic myopathy, inflammatory myopathy showed increased values (beyond M + 2SD of control) both in G6PDH and RNA. There were significant positive correlations between G6PDH activity and RNA content in PMD and motor neuron disease. Myotonic dystrophy showed normal values in both G6PDH and RNA. Half number of cases of mitochondrial myopathy demonstrated increased G6PDH alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Studies on enzyme activities relating to amino acid mobilization in biopsied muscles].

We evaluated glutamine synthetase (GS) and alanine aminotransferase (GPT) activities in biopsied muscle from 40 cases of various neuromuscular diseases. GS and GPT catalyze the synthesis of glutamine and alanine, respectively, from amino acids derived in part from the breakdown of muscle proteins. The subjects were 7 cases of muscular dystrophy; 1 Duchenne type (DMD), 3 limb-girdle type, 2 facioscapulohumeral type (FSH), 1 Fukuyama type (FCMD); and 1 myotonic dystrophy (MyD); 5 mitochondrial myopathies; 11 inflammatory myopathies including 6 polymyositis and 3 myopathy associated with collagen disease; 5 endocrinological myopathies including 2 periodic paralysis; and, 11 cases of neurogenic amyotrophies [4 amyotrophic lateral sclerosis (ALS), 4 spinal progressive muscular atrophy (SPMA) and 3 other types]. Control subjects were 8 patients with thigh operations. Biopsied muscle was homogenized and assayed for GS activity by the method of Smith et al.; GPT was assayed by commercial kit. Protein was assayed by the method of Lowry et al. Enzyme activities between mean -2SD and mean +2SD of controls were considered to be the normal range. GS activity in control subjects was 28.22 +/- 7.13 (mean +/- SD) nmol glutamine formed/mg protein/hr. Fifteen of 40 cases showed increased enzyme activity, including DMD and FCMD, the acute phase of polymyositis, and periodic paralysis. GPT activity in controls was 16.56 +/- 4.05 IU/mg protein. Sixteen of 40 patients showed increased enzyme activity: FCMD, FSH, MyD, inflammatory and endocrinological myopathy, and ALS. On the other hand, mitochondrial myopathy showed significantly decreased activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[An MRI study of hereditary spinocerebellar degenerations].

We evaluated magnetic resonance image (MRI) in 21 cases of hereditary spinocerebellar degenerations (SCD) of autosomal dominant trait. By the discriminant formula based on size of the cerebellar vermis and ventral pons, which was reported in our previous study, the patients were classified into three types. Group 1 included the cases with atrophies in the vermis and pons; OPCA type. Group 2 showed vermian atrophy and less significant atrophy in pons; LCCA type. And Group 3 was no significant atrophies both in vermis and pons. Cases in Group 1 were furthermore divided into two groups according to width of the midbrain tegmentum. Group 1A, with normal midbrain tegmentum, was consisted of five cases. Four cases were diagnosed as Menzel type OPCA. Another case showed various clinical symptoms and relatively mild atrophies for his duration of illness. His family members were classified to Group 3. Seven cases in Group 1B showed reduced midbrain tegmentum. Four cases showed ataxia, spasticity, ocular symptoms, bladder dysfunction and amyotrophy with or without fasciculation, and they seemed to be a special type of SCD mimicking Joseph disease. One case showed bulging eyes, ocular movement palsy and dystonia. However, his sister manifested only ataxia with very mild ocular movement disorder. Their MRI demonstrated severe atrophies in the cerebellum, pons and afferent cerebellar peduncli, and this pedigree was thought to be Menzel type OPCA with various associated disorders. Another case was clinically diagnosed as dentate-rubro-pallido-luysian atrophy. Group 2 was consisted of 6 cases who were clinically diagnosed as Holmes type LCCA. MRI demonstrated medial dominant cerebellar atrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[MRI findings of the tongue in neurodegenerative diseases with bulbar sign].

We examined the magnetic resonance image (MRI) of the tongue in cases of amyotrophic lateral sclerosis (ALS), bulbo-spinal muscular atrophy (SBMA) and Shy-Drager syndrome (SDS) with sleep apnea. ALS case with severe bulbar disorder showed atrophic, irregularly margin tongue with increased signal intensity in T1-weighted MRI. ALS with less severe bulbar disorder demonstrated mixed hyperintensity and normointensity areas in the tongue. ALS without lingual symptoms showed increased intensity of tongue which suggested subclinical involvement of lingual muscle. BSMA case also showed atrophic tongue with diffusely increased signal intensity. SDS case with sleep apnea was revealed to have round shaped tongue without increased signal intensity, but his tongue fell into the posterior oral cavity, indicating hypotonus of genioglossus muscle. We concluded that MRI of the tongue is useful to determine the bulbar symptoms due to lower neuron disorder or not.

Aged↗
PubMed1990

[MRI study of three siblings of suspicious Sjögren-Larsson syndrome].

We report the characteristics of high field magnetic resonance imaging (MRI) of three siblings with hereditary spastic paraplegia (HSP), probably of autosomal recessive inheritance. The proband was a 25-year-old woman who manifested slowly progressive spastic paraplegia, mental deficit, decayed teeth since her childhood. The siblings of the proband, 29-year-old woman and 27-year-old man, also showed the same clinical course as hers, and the symptoms are more severe in elder siblings. The proband solely had ichthyosis on her neck and lower thighs, which suggested Sjögren-Larsson syndrome. Sagittal and transverse slices of high field MRI (1.5T), T2-weighted (SE 2800/90) and T1-weighted (500/15) images were obtained. The cerebral atrophies were observed in the frontal and the parietal lobes, especially at the precentral and superior frontal gyri, whereas the occipital lobes were relatively spared. The atrophies of motor cortex seemed to be responsible for the disorder of voluntary movement. T2WI demonstrated a diffuse hyperintensity in the cerebral white matter, which suggested demyelination. T2WI also showed remarkable hypointensities in the globus pallidus, putamen, and thalamus. The degenerative involvement in these regions was also suspected. These abnormal intensities, both hyper- and hypo-intensities, were stronger in elder siblings, which indicated the intensity changes to be of progressive nature. Severe atrophy or hypoplasia of corpus callosum was also observed, however the cingulate gyri could be confirmed. We were not able to detect the callosal disconnection syndrome, because of their severe mental impairment. Spinal cord was slender and its degenerative changes were suggested. The high field MRI of a HSP family showed the extensive abnormal findings of the central nervous system in this HSP family, such as cerebral motor area, extrapyramidal system, corpus callosum, and spinal cord.

Adult↗
PubMed1990

[MRI study of hemiballism].

MRI findings of four hemiballism cases are described, and pathophysiology, pathogenesis and treatment of hemiballism are discussed. All cases had no family history. The lesions revealed by MRI and the pathogenesis were different each other. Case 1, a 17 years aged girl with a history of hyperthyroidism and repeated tonsillitis, showed right sided hemiballism which was recovered by prednisolone and haloperidol. Although her involuntary movement was ameliorated by administration of sodium valproate and phenytoin, phenytoin caused allergic agranulocytosis which required prednisolone treatment. T2 weighted MRI at the 31st disease day demonstrated hyperintensities in the left caudate nucleus, putamen, lateral pallidum, perirubral area and substantia nigra. Hyperintensity in the prerubral area suggested involvement of the subthalamic nucleus or its connecting pathway. Fourteen months later, she suffered from convulsion and mental confusion. There were theta wave bursts and delta waves in EEG. No abnormal findings in MRI and positive antinuclear antibody (ANA: X320, speckled type) were observed. Case 2, a 78 year aged woman, suffered from right sided hemiballism. MRI findings at the 58th disease day were the left putaminal infarction and lacunar state in the bilateral caudate nuclei and the deep white matter of the centrum semiovale. There were no abnormal findings in the subthalamic nucleus. Case 3, a 51 year aged man with diabetes mellitus, had right sided hemiballism. X-ray CT at the 8th disease day showed hyperdensity in the left subthalamic nucleus region which could not be observed at the 12th day. Hypointensity in the left subthalamic nucleus region was observed in both T2 weighted and proton density MRI at the 52nd day. Case 4, an 82 year aged woman, had right sided hemiballism which remarkably diminished at the third disease day and disappeared by the fifth day. Any pathogenic lesion concerning to hemiballism was detected by X-ray CT or MRI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Study of the blink reflex in spinocerebellar degeneration].

Blink reflex (BR) was composed of R1 and R2. R1 is considered to indicate the brainstem function. The purpose of this study was to evaluate the brainstem function of spinocerebellar degeneration (SCD) by the R1 latency (R1). BR was evoked by the percutaneous stimulation of supraorbital nerve. And R1 was measured by the action potential of orbucularis oculi muscle. Direct response was recorded by the percutaneous stimulation of facial nerve to determine the terminal latency of facial nerve (D). By these methods R1, D, R1/D and difference between at right and left side of these data (delta R1, delta D, delta R1/D) were measured in 21 normal subjects (57.7 +/- 10.1 ys.) and 28 cases of SCD (56.6 +/- 8.2 ys.), including 12 cases of sporadic type olivopontocerebellar atrophy (SOPCA), 4 of Menzel type olivopontocerebellar atrophy (MOPCA), 6 of late cortical cerebellar atrophy (LCCA) and 6 of Holmes type cortical cerebellar atrophy (HCCA). There was no difference between all types of SCD and normal subject at D, but significant difference of R1 and R1/d was observed between at MOPCA and normal subject. Concerning the difference between right and left side delta R1 and delta R1/D showed the significant difference with MOCA and SOPCA, but delta D showed no difference. Elongation of R1 and R1/D without the delay of facial nerve and the significant difference of R1 and R1/d between at right and left side suggested the synaptic transmission disorder form trigeminal nerve to facial nerve at brainstem of MOCA.

Adult↗
PubMed1989

Histamine synthesis after administration of gastrin and blockade of acid secretion in the rat stomach.

Histidine decarboxylase (HDC) activity in the oxyntic gland and gastric volume were measured in rats treated with tetragastrin, cimetidine or omeprazole. HDC activity was dose dependently activated by not only tetragastrin but also cimetidine and omeprazole treatment. Histamine concentration in the oxyntic gland was reduced, but the amount of histamine in the gastric contents was increased by tetragastrin treatment. In rats premedicated with cimetidine or omeprazole, histamine concentration in the oxyntic gland and the amount of histamine in the gastric contents were not changed by administration of tetragastrin. It was concluded that tetragastrin activated HDC which increased histamine release into the gastric contents. Cimetidine and omeprazole induced the secretion of endogenous gastrin, leading to the activation of HDC.

Animals↗
PubMed1989

[Correlation of clinical course with MRI findings in olivo-pontocerebellar atrophy and late-cortical cerebellar atrophy].

We quantitatively analyzed 1.5 T MRI in 36 cases of sporadic spinocerebellar degeneration (SCD) and 30 control cases without intracranial lesions, using graphic analyzer. SCD consisted of 21 olivo-ponto-cerebellar atrophy (OPCA) and 15 late cortical cerebellar atrophy (LCCA). There was negative correlation between vermian size and the duration of illness both in OPCA (r = 0.8960, p less than 0.001) and LCCA (r = 0.7756, p less than 0.01), but the progression rate in OPCA was three times greater than that in LCCA. LCCA was suggested the preclinical vermian atrophy by the statistical regression study. In OPCA, the duration of illness also revealed significant correlations with atrophy of ventral pons (r = 0.8308, p less than 0.001) and also cerebellar hemisphere (medial hemisphere; r = 0.7278, p less than 0.001. lateral hemisphere; r = 0.6039, p less than 0.01). OPCA showed diffuse atrophy of cerebellar hemisphere, whereas LCCA showed medial dominant atrophy. OPCA demonstrated significant correlation between the fourth ventricle dilatation and the duration of illness (r = 0.6005, p less than 0.01). A discriminant study significantly separated OPCA, LCCA and control each other by sizes of ventral pons and cerebellar vermis (p less than 0.001). In T2 weighted MRI, 10 cases out of 14 LCCA did not show hypointensity in dentate nucleus in spite of normal appearance in the other portions usually decreased intensity. The dentate nucleus of OPCA showed a significant atrophy. The incidence of putaminal hypointensity in OPCA was significantly greater than that of control group (chi-square = 6.476, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[A case of juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated cervical fusion at the C3-C4 levels].

The case, 29-year-old male, had suffered from muscular weakness and atrophy of the bilateral forearms and hands with tremor of the bilateral fingers for about 13 years. A neurological examination showed normal muscle-stretch reflexes and no sensory disturbances. A cervical spinogram revealed a fusion at the C3-C4 levels and mild spondylotic changes. We clinically diagnosed him as juvenile-type distal and segmental muscular atrophy of upper extremities (Hirayama disease) with the isolated congenital cervical fusion. Magnetic resonance imaging demonstrated an enlargement of the anterior epidural space from the C4-C5 levels to the Th 1-Th 2 levels. This abnormal epidural space showed relatively high signal intensity partially with low signal intensity on the T2 weighted spin-echo image and decreased in signal on the T1 weighted spin-echo image. And the dural sac was shifted backward and narrowed. And the soft discs was slightly protruded at the level of C4-5, C5-6 and C6-7. These findings suggest the over swelling and the delayed blood flow of the internal vertebral venous plexus. In this case, the degeneration of the cervical spine and soft disc derived from the congenital cervical fusion seems to have caused the internal vertebral venous plexus congestion and then have damaged the anterior horn cells.

Adult↗
PubMed1988

Nuclear glucocorticoid receptor binding in L6 skeletal muscle cells in culture.

Mechanisms underlying glucocorticoid hormone actions on skeletal muscle remain incompletely understood. This problem may be amenable to solution with a simple cell culture system in which the hormonal environment can be controlled. In this report, we demonstrate that the L6 muscle cell line may provide such a system. These cells, which possess many morphological and functional characteristics of skeletal muscle, originate as mononuclear myoblasts, which fuse to form multinucleated myotubes. L6 myoblasts and myotubes contain an intracellular glucocorticoid receptor that has binding parameters and ligand specificity similar to those of glucocorticoid receptors of classical glucocorticoid target tissues. A major advantage of the use of cultured cells is ease of isolation of myonuclei that display specific glucocorticoid receptor binding. L6 muscle cells should provide a valuable model system for further studies of the mechanisms of glucocorticoid hormone actions on muscle.

Animals↗
PubMed1988

Dexamethasone regulates glutamine synthetase expression in rat skeletal muscles.

The regulation of glutamine synthetase expression by dexamethasone was studied in rat skeletal muscles. Daily administration of dexamethasone caused striking enhancement of glutamine synthetase activity in plantaris, soleus, and diaphragm muscles. Northern blot analysis revealed that the dexamethasone-mediated increase of glutamine synthetase activity was associated with dramatically increased levels of glutamine synthetase mRNA. Both glutamine synthetase activity and mRNA levels were significantly elevated in plantaris muscle at 0.5 mg.kg-1.day-1 of dexamethasone, a dose that approximates endogenous corticosteroid levels in animals under severe stress. Quantification of changes in glutamine synthetase mRNA on the basis of total mRNA (by oligo dT hybridization) also revealed a major increase in glutamine synthetase mRNA. Dexamethasone was without effect on beta-tubulin mRNA levels, indicating that glutamine synthetase induction is not part of a global response to glucocorticoids. Dexamethasone treatment resulted in only an approximately 15% increase in glutamine synthetase activity in heart; there was no change in glutamine synthetase mRNA level in this tissue. Thus glucocorticoids regulate glutamine synthetase gene expression in rat skeletal muscles.

Animals↗
PubMed1988

A case of spontaneous esophageal rupture treated with conservative therapy.

A 51 year-old male was admitted because of abrupt hematemesis and loss of consciousness. Emergency endoscopy depicted a giant esophageal ulcer on the left side extending from the middle intrathoracic region to the lower intrathoracic region. Esophagography, performed on the second day of admission, revealed a huge cavity (10 cm x 7 cm) filled with contrast medium resulting from a rupture in the ulceration. His state of shock improved with conservative therapy and no severe mediastinitis was noted. The drainage from the cavity into the lumen of the esophagus was considered to be acceptable from esophagography and an endoscopic examination. Secondary to his stable condition and continuous drainage, this patient was treated conservatively throughout his clinical course. The patient was given intravenous hyperalimentation (IVH) until the 25th hospital day and was medicated with broad spectrum-antibiotics. On the 21st hospital day the size of the esophageal cavity was markedly decreased (7 cm x 2 cm). Only small irregular mucosa was noted on the esophagogram taken 6 weeks after admission. Six months after the onset, an X-ray examination revealed complete healing of the spontaneous esophageal rupture with no recurrence.

Anti-Bacterial Agents↗
PubMed1988

Activity and distribution of histidine decarboxylase and histamine concentration in rat stomach.

The involvement of histamine in mediating gastric function under normal and pathological conditions has been largely established. Histidine decarboxylase (HDC) is the only synthetic enzyme of histamine in the mast cell or enterochromaffin like (ECL) cell. In this study, we examined, the activity of HDC by a method based on the modification of Kobayashi's method, the histological distribution of HDC containing cells was determined by an immunohistochemical method and the histamine concentration by a HPLC method in rat stomach. Histamine concentration in the total gastric layer of the fundus is overwhelming large compared to that in the antrum. On the other hand, histamine concentration of the mucosal layer of the fundus is 72.1 +/- 0.4 micrograms/g (mean +/- S.D.) and that in both the muscular and serosal layers is 7.2 +/- 0.4 micrograms/g. HDC activity of the total gastric layer of the fundus was about ten times as high as that in the antrum. Histological distribution of HDC-containing endocrine cells was observed in the basal part of the gastric mucosa of the fundus, but could not be observed in the muscular and serosal layer. These results suggest that HDC-containing endocrine cells, in only the basal parts of the mucosal layer of the fundus, were similar to ECL cells and have important parts for biosynthesis of internal gastric histamine. Therefore, using the total gastric layer of the stomach was thought to be easier than using only the mucosal layer for measuring gastric histamine and HDC-activity in rats.

Animals↗
PubMed1987

Increased serum myosin light chain 3 level in neuromuscular diseases.

A radioimmunoassay for human skeletal muscle myosin light chain 3 (MLC-3) was developed. The serum level of MLC-3 was evaluated in 143 patients suffering from neuromuscular diseases. Increased MLC-3 level was observed in muscular dystrophies. There were significant positive correlations between serum levels of MLC-3 and creatine kinase (CK) in Duchenne and limb-girdle type muscular dystrophy, but the regression lines were different. Patients with neurogenic amyotrophy, especially amyotrophic lateral sclerosis, also showed elevated MLC-3 levels with or without high CK, and the frequency of increase in MLC-3 was greater than that of CK. The results of the present study suggest that circulating MLC might be a useful marker for muscle breakdown not merely in myopathies but in neurogenic disorders.

Circadian Rhythm↗
PubMed1987

Evaluation of the endogenous glucocorticoid hypothesis of denervation atrophy.

We studied the effects of oral administration of RU38486, a potent and selective glucocorticoid antagonist, on muscle weight, non-collagen protein content, and selected enzyme activities (choline acetyltransferase, glucose-6-phosphate dehydrogenase, and glutamine synthetase) following denervation of rat skeletal muscle. Neither decreases in muscle weight, protein content, and choline acetyltransferase activity, nor increases in the activities of glucose-6-phosphate dehydrogenase and glutamine synthetase were affected by RU38486. These data do not support the hypothesis that denervation atrophy results from enhanced sensitivity of muscle to endogenous glucocorticoids.

Animals↗