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Biomedical subjects

M Inagaki

Publications and source records attributed to M Inagaki.

At least 289 records · Page 16Linked to original sources

Myoclonic astatic epilepsy presenting eyelid myoclonic seizures induced by closing of eyes.

A male infant with myoclonic astatic epilepsy showed myoclonic seizures of the eyelids by closing of the eyes. There was no photosensitivity in EEG with flash-stimulation and he could induce seizures even in total darkness. The latency between a lid closure and onset of seizure discharges on EEG was relatively long (0.3-0.5 second). Epileptic seizures in this patient may be induced via a brainstem reticular formation, and elevated Bell's position seems to be the necessary stimulus to produce seizures.

Blinking↗

Inhibitory effects of high doses of intravenous gamma-globulin on platelet interaction with the vessel wall in Kawasaki disease.

Clinical effects of high-dose gamma-globulin therapy in Kawasaki disease have been evaluated from the viewpoints of its inhibitory effects on platelet adhesion and thrombus formation on the vessel wall. Platelet adhesion to the subendothelium is the fist step of thrombosis as well as platelet interaction with the vessel wall, which can be observed experimentally by Baumgartner's method. Twelve patients with Kawasaki disease treated with intact intravenous gamma-globulin (IVGG) showed decreased platelet adhesion in contrast to ten patients treated with only aspirin (ASA) or flurbiprofen (FP). Addition of intact IVGG to normal blood in Baumgartner's method also resulted in decreasing platelet adhesion and thrombus formation; however, other pepsin-treated IVGG caused enhanced platelet adhesion and thrombus formation. Moreover, pretreatments of the vessel wall with both types of IVGG showed effects similar to those of addition. In conclusion, high-dose therapy with intact IVGG has inhibitory effects on platelet adhesion and thrombus formation. Although the mechanism of the effects is not yet clear, some competitive inhibition between intact IgG and adhesive protein such as von Willebrand factor is suggested, and Fc receptors of the platelet membrane and Fab and Fc receptors of the subendothelium of the vessel wall may have some role in the interaction.

Coronary Thrombosis↗

High sensitivity of neonatal rat hepatocytes to retroviral-mediated gene transfer and their transplantation into the spleen of adult rat.

To optimize conditions for retroviral-mediated transfer of a recombinant gene to hepatocytes, the pMNSM-Tk-lacZ vector, which we had constructed to express the bacterial beta-galactosidase gene, was transduced to rat hepatocytes under various conditions, and the expression of beta-galactosidase activity was examined by cytochemical staining. Compared to the hepatocytes of adult rats, those of newborns were about 50-100 times more sensitive to transduction with the beta-galactosidase gene in vitro. The sensitivity was high in the newborn hepatocytes when the virus was infected on days 1 and 2 after initiation of culture. However, the sensitivity to infection did not correlate with the DNA synthetic activity. The gene transfer was feasible not only to hepatocytes in monolayer culture but also to those in spheroid culture. The spheroidal aggregates containing hepatocytes transduced with the beta-galactosidase gene could be transplanted into the spleen of syngenic adult rat, although the expression was very low.

Animals↗

Systemic histopathology of rats with CCl4-induced hepatic cirrhosis.

Systemic histopathological examinations were carried out on rats with CCl4-induced hepatic cirrhosis. Moderate congestion in the spleen, prominent oedema in the focal acinar cell degeneration in the pancreas, marked haemorrhage and phagocytosis of haemosiderin by macrophages in the pancreaticoduodenal lymph node, appearance of monocytes bearing haemosiderin-like granules in the pulmonary arteries and cardiac right atrium, and focal segmental glomerulosclerosis were consistently observed in rats with hepatic cirrhosis. In addition, a marked increase in number of target cells and the appearance of a small number of monocytes bearing haemosiderin-like granules were also commonly found in the peripheral blood smears of these animals. These findings are considered to be important in the use of the CCl4-induced model of hepatic cirrhosis in the rat.

Animals↗

Cat pontine omnipause neurons: direct inhibitory connection with Forel's field burst neurons participating in the genesis of vertical saccades.

This study investigates synaptic connections of omnipause neurons (OPNs) in the midline pontine tegmentum with vertical medium-lead burst neurons (BNs) in the Forel's field H (FFH), using the microstimulation and spike-triggered averaging techniques in chronically prepared alert cats. OPNs on both sides were antidromically activated by microstimulation at the recording sites of the BNs. Systematic tracking with the stimulating microelectrode revealed indications of profuse axonal branching of OPNs within the BN area. Antidromic spikes of the BNs evoked from the oculomotor nucleus and spike bursts of the BNs associated with saccades were suppressed by OPN area microstimulation. Averaged field potentials in the BN area triggered by spikes of OPNs showed monosynaptic positive waves. These results all but confirm the existence of direct inhibitory synaptic connections of OPNs with the BNs in the FFH. The role of OPNs in the genesis of vertical saccades was also discussed.

Animals↗

[Conventional X-ray versus CT in diagnosis of chronic sinusitis in children].

The interpretation of conventional radiographic views for sinusitis in children has given rise to considerable controversy. Thirty-three children (66 sides of sinuses) aged from 4 to 15 years who were suspected of having chronic sinusitis were studied to determine the accuracy of conventional X-ray examination, comparing the results with those of CT. Coronal CT was taken after conventional X-ray examination (Waters and occipito-frontal views), and the time interval between these two examinations was 0 to 14 days (average 5.1 days). The rate of correspondence in diagnosis of sinus pathology between conventional X-ray views and CT was 74.3% in the maxillary sinus and 40.9% in the ethmoid. The rate of overestimation with conventional X-ray views was 24.2% in the maxillary sinus and 56.1% in the ethmoid, while that of underestimation was 1.5% and 3.0% in the maxillary and the ethmoid sinus respectively. The incidence of false positives according to conventional X-ray views was 8.0% in the maxillary sinus and 33.3% in the ethmoid. Our results indicate that Waters view is sufficient to diagnose maxillary sinus pathology in children. However, additional radiologic examinations, such as CT, are necessary in investigating the pathologic conditions of the ethmoid sinus, since diagnostic significance of occipito-frontal view for ethmoid pathology is doubtful in children. A routine preoperative CT is recommended, which allows a detailed evaluation of pathologic changes and anatomical relations of the ethmoid before embarking a surgical intervention for the ethmoid sinus in children.

Adolescent↗

[Relationship between electroencephalographic abnormality and late blink reflex responses in infantile spasms and EIEE].

Electrically elicited blink reflex (BR) were analyzed in seven patients with age dependent epileptic encephalopathies (5 patients with infantile spasms and 2 with EIEE). Four patients with infantile spasms showed prolonged latency of the late BR responses (R2). In 2 patients with EIEE showing suppression burst pattern on EEG, R2 was not detectable. R2 abnormality in BR might reflect the dysfunction of the brainstem reticular formation in age dependent epileptic encephalopathies.

Age Factors↗

[Hypertrophic cardiomyopathy associated with anomalous origin of the left coronary artery from the right sinus of valsalva].

A 47 year old Japanese male with exertional shortness of breath, cardiac murmur and ECG abnormalities was examined with invasive and non-invasive cardiology techniques that disclosed hypertrophic cardiomyopathy, and the anomalous origin of the left coronary artery from the right sinus of Valsalva. Although both situations have been known to cause sudden death especially under a state of strenuous physical stress, his exercise thallium scintigraphy performed with the symptom limited maximal test did not uncover any significant myocardial ischemia or exercise induced malignant arrhythmias. This is a very rare association of two distinctly identified clinical situations highly indicative of a likelihood of sudden cardiac death. Therefore, careful observation is needed.

Cardiac Catheterization↗

[A two-year-old clinically manifesting carrier of Duchenne muscular dystrophy].

A two-year-old symptomatic carrier of Duchenne muscular dystrophy (DMD) confirmed by dystrophin immunohistochemical study was reported. She had mild proximal muscular weakness and elevated serum creatine kinase (CK) level. There were no family members of DMD. CT examination revealed low density areas in the muscles similar to that seen in the early stage of DMD. Biopsied specimen of muscle showed myopathic changes with necrotic and regenerating fibers. The immunohistochemical study using an antiserum against dystrophin showed the mosaic expression of the surface membrane, with positive and negative patches. Accordingly, she was strongly suggested to be a DMD carrier. This case shows that dystrophin immunohistochemistry is useful for diagnosis of a DMD carrier without affected family members.

Child, Preschool↗

[Charcot-Marie-Tooth disease associated with dilated cardiomyopathy: an autopsy case report].

This is a clinical report of a rare case of Charcot-Marie-Tooth disease associated with dilated cardiomyopathy. A seventy-seven-year-old Japanese male first visited our outpatient clinic with a ten-year history of muscular weakness in his bilateral lower extremities and gait disturbance characterized by classical features of peroneal muscular atrophy and inverted champagne bottle legs. Biopsy findings of the m. quadriceps femoris and the n. gastrocnemius revealed clustered atrophy of myofibrils and segmental demyelinization mingled with remyelinization. Because of his other problem of dilated cardiomyopathy, he had been treated with salt restriction, digitalis, diuretics and vasodilators, until his third hospitalization, when he developed terminal stage of severe congestive heart failure. Despite our intensive cardiac care, the patient died because of profound pump failure. Autopsy findings disclosed a remarkably dilated left ventricular chamber and an increased total heart weight of 600 grams. Grossly, the cross sectional view of the left ventricle revealed diffuse, but not homogenous fibrosis that was most prominent in the posterior wall. On light microscopic examination, the left ventricular myocardium revealed diffusely scattered muscular degeneration interlaced with fibrosis. Although large epicardial coronary arteries revealed only mild intimal atheromatous thickening, most of the small intramuscular coronary arteries were free from atherosclerosis. Neither diabetic nor amyloid lesions could be detected. It has been well known that cardiomyopathy is often associated with various forms of muscular dystrophy and Friedreich's ataxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrophy↗

Activation of a serine/threonine kinase that phosphorylates microtubule-associated protein 1B in vitro by growth factors and phorbol esters in quiescent rat fibroblastic cells.

We have previously found and characterized a mitogen-activated, serine/threonine-specific protein kinase that specifically phosphorylates microtubule-associated protein 2 (MAP2) in vitro, which we call here MAP2 kinase [Hoshi, M., Nishida, E. & Sakai, H. (1988) J. Biol. Chem. 263, 5396-5401; Hoshi, M., Nishida, E. & Sakai, H. (1989) Eur. J. Biochem. 184, 477-486]. In this study, we have found another serine/threonine-specific protein kinase that is activated by various mitogens. The activated kinase utilized microtubule-associated protein 1B (MAP1B) as the major substrate in vitro, so we tentatively call it MAP1B kinase (M1BK). M1BK was maximally activated 20-30 min after treatment of quiescent rat fibroblastic 3Y1 cells with epidermal growth factor (EGF), while MAP2 kinase was maximally activated within 5-10 min of EGF treatment. The EGF-activated M1BK was eluted at about 0.15 M NaCl on a DEAE-cellulose column, while the activated MAP2 kinase was eluted at about 0.1 M NaCl under the conditions used. The EGF-activated M1BK was eluted as a single peak just after the activated MAP2 kinase on an HPLC gel-filtration column. Histone, casein and ribosomal protein S6 were very poor substrates for the M1BK, while MAP2 and myelin basic protein were moderate substrates. The M1BK activity in cell extracts was inhibited by Ca2+, glycerol 2-phosphate and Zn2+, and slightly enhanced by heparin. These data suggested that M1BK is distinct from previously described mitogen-activated kinases such as MAP2 kinase, casein kinase II and S6 kinase. Pretreatment with cycloheximide or puromycin did not block the M1BK activation by EGF. Furthermore, incubation of the EGF-activated M1BK with acid phosphatase inactivated the kinase activity. Therefore, M1BK may be activated by phosphorylation in EGF-treated cells. In addition to EGF, 12-O-tetradecanoylphorbol 13-acetate, platelet-derived growth factor and insulin-like growth factor-I also induced the activation of M1BK in quiescent cells.

Animals↗

Mitosis-specific histone H3 phosphorylation in vitro in nucleosome structures.

A mechanism of mitosis-specific enhancement of histone H3 phosphorylation was analyzed in vitro in terms of nucleosome structure. The incorporation of [32P]phosphate into DNA-bound H3 was approximately 5-7 times higher than in DNA-free H3 using the catalytic subunit of cAMP-dependent protein kinase. The two major N-terminal serine sites, including the mitosis-specific site (Ser10) and Ser28, were extensively phosphorylated in the DNA-bound forms. These phosphorylation patterns were identical to those of nucleosomal H3. In contrast, the H3 in DNA-free octamers was very slightly phosphorylated. The major site of H3 phosphorylation in DNA-free H3 was Thr118 in the C-terminus. Results indicate that DNA-binding is essential for the high level of mitosis-specific H3 phosphorylation, and that the nucleosome structure promotes H3 N-terminal phosphorylation in vitro. It also suggests the possibility that H1 prevents H3 phosphorylation during interphase of the cell cycle.

Animals↗

Ca2(+)-calmodulin-dependent protein kinase II phosphorylates various types of non-epithelial intermediate filament proteins.

We have investigated the actions of Ca2(+)-calmodulin (CaM)-dependent protein kinase II on various types of non-epithelial intermediate filament proteins, vimentin, desmin, glial fibrillary acidic protein (GFAP) and neurofilament triplet proteins. Most of these filament proteins could serve as substrates. The effects of phosphorylation on the filamentous structure of vimentin were investigated in sedimentation experiments and by using electron microscopy. The amount of unassembled vimentin increased linearly with increased phosphorylation. However, the extent of the effect of phosphorylation on the potential to polymerize was also affected by the MgCl2 concentration, under conditions for reassembly. The actions of Ca2(+)-CaM-dependent protein kinase II on non-epithelial intermediate filaments under physiological conditions are given attention.

Animals↗