Biomedical subjects

S Nogawa

Publications and source records attributed to S Nogawa.

49 records · Page 3Linked to original sources

PubMed1994

A MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) mtDNA mutation that induces subacute dementia which mimicks Creutzfeldt-Jakob disease.

A 50-year-old woman with subacute dementia and brain atrophy on CT showed periodic synchronous discharge (PSD) on electroencephalogram (EEG) and myoclonus. She was initially suspected of suffering from Creutzfeldt-Jakob disease (CJD), but dramatically recovered over 5 months. Based on further investigations, the final diagnosis was mitochondrial encephalomyopathy with an A-to-G substitution at nucleotide position 3243 in mitochondrial DNA (mtDNA), commonly seen in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). This case suggests that patients suspected of suffering from CJD should be evaluated for mitochondrial encephalomyopathy.

Creutzfeldt-Jakob Syndrome↗

PubMed1993

Immobilization stress induces alterations of second-messenger systems in the gerbil brain.

The effects of immobilization stress on the cerebral second messenger (adenylate cyclase and phosphoinositide) were investigated autoradiographically in mongolian gerbils. After 10 min (10-min stress group, n = 7), or after 6 h (6-h stress group, n = 7) of fixation on a flat board while supine, in vitro autoradiography was performed using [3H]forskolin (3H-FK) and [3H]phorbol-12,13-dibutyrate (3H-PDBu) as specific ligands to identify the distribution of adenylate cyclase and protein kinase C, respectively. In another group of 7 gerbils (control group), the same autoradiographic procedure was performed immediately after the animals were removed from the cage. In the 10-min stress group, FK binding was significantly decreased in the hypothalamus and amygdala, but significantly increased in the basal ganglia including the caudate-putamen and globus pallidus. FK binding in the 6-h stress group tended to increase throughout the brain, rising significantly in the basal ganglia. PDBu binding in either stress group did not change significantly compared to the control group in any region except the hippocampal CA3 region of the 6-h stress group. Under immobilization stress, the adenylate cyclase system may undergo time-dependent and regionally specific changes, while the phosphoinositide system remains relatively stable.

Adenylyl Cyclases↗

PubMed1993

Reduction in second-messenger ligand binding sites after brain ischemia--autoradiographic Bmax and Kd determinations using digital image analysis.

Changes in forskolin (FK) and phorbol 12,13-dibutyrate (PDBu) binding were evaluated in relation to local cerebral blood flow (CBF) after 6-h unilateral carotid artery occlusion in the gerbil striatum employing a quantitative autoradiographic method, which permitted these three parameters to be measured in the same brain. CBF was measured by the [14C]iodoantipyrine method at the end of the experiment. [3H]FK and [3H]PDBu were utilized as specific ligands to assess the activity of adenylate cyclase (AC) and protein kinase C (PKC), respectively. A saturation study was undertaken to measure the Kd (dissociation constant) and Bmax (maximal binding capacity) of each ligand by digital image processing of sequential autoradiograms employing pixel-by-pixel Scatchard analysis. The Bmax values of FK and PDBu were significantly decreased on the ischemic side, but the reduction in Bmax of FK was greater than that of PDBu. The K4 of each ligand remained unchanged. The FK binding underwent a progressive decline as CBF fell below 30 ml/100 g/min. The PDBu binding showed only a gradual decline in parallel with the CBF reduction. These findings suggest that a reduction in CBF below 30 ml/100 g/min for 6 h may induce a remarkable suppression of the AC system with less significant inhibition of the PKC system in the striatum.

Adenylyl Cyclases↗

PubMed1993

Inhibition of nitric oxide synthesis impairs autoregulation of local cerebral blood flow in the rat.

The effect of intravenous administration of NG-monomethyl-L-arginine (L-NMMA, 30 mg kg-1), a specific inhibitor of nitric oxide (NO) synthesis, on the autoregulation of local cerebral blood flow (LCBF) was examined in the rat using the [14C]iodoantipyrine autoradiographic method. LCBF was significantly lower in various superficial regions such as the cerebral cortices and cerebellar cortex and in several deep brain regions in animals with haemorrhagic hypotension induced after L-NMMA infusion (the L-NMMA + HEM group) compared with animals without haemorrhagic hypotension after L-NMMA infusion (the L-NMMA group). The present findings suggest that NO synthesis may play a crucial role in the autoregulation of LCBF in response to a reduction in blood pressure in the cerebral cortices, cerebellar cortex and several deep brain regions.

Animals↗

PubMed1993

[Alteration of inositol 1,4,5-trisphosphate receptor binding after 6-hour hemispheric ischemia in the gerbil brain].

Inositol 1,4,5-trisphosphate (IP3) has recently been known to play vital roles as one of the second messengers to control intracellular metabolism of calcium ion. Therefore, alterations of IP3 receptor binding and local cerebral blood flow (1CBF) were evaluated at 6 hours after occlusion of the right common carotid artery in the gerbil brain. The autoradiographic method developed in our laboratory enabled us to measure both parameters in the same brain. Animals attaining more than 5 in their ischemic scores, which were assessed at 1 hour after the occlusion, were utilized. LCBF was measured by the 14C-iodoantipyrine method at the end of the experiment. After frozen brains were cut into serial slices on a cryostat, the IP3 receptor binding was evaluated in vitro by using 3H-inositol 1,4,5-trisphosphate as the ligand. LCBF fell below 10 ml/100 g/min in most of the cerebral regions on the occluded side. In contrast a significant reduction in IP3 binding was noted only in the hippocampus CA1 on the occluded side. The IP3 binding tended to decrease when the values of 1CBF were reduced below 20 ml/100 g/min in this region. These findings suggest that the selective alteration of IP3 receptor binding in the hippocampus CA1 may be closely associated with the selective vulnerability of this region to ischemia.

Animals↗

PubMed1992

Local cerebral blood flow and its response to intravenous levodopa in progressive supranuclear palsy. Comparison with Parkinson's disease.

The local cerebral blood flow (LCBF) at steady state and after the intravenous administration of levodopa (1 mg/kg) was measured by the xenon-enhanced computed tomographic method in six patients with progressive supranuclear palsy (PSP) and in nine patients with idiopathic Parkinson's disease. The baseline LCBF values in most brain regions in patients with PSP were lower than those in patients with Parkinson's disease, and hyperfrontality of the LCBF was lost. In patients with Parkinson's disease, the injection of levodopa markedly increased LCBF, especially in the striatum, thalamus, and internal capsule (approximately 40%). In patients with PSP, however, levodopa did not increase the LCBF in all brain regions examined. The LCBF increases after the administration of levodopa in patients with Parkinson's disease may be secondary to metabolic activation of the dopaminergic system. The different LCBF responses to levodopa between patients with PSP and those with Parkinson's disease may reflect differences in pathologic features, such as in the degree of preservation of nigrostriatal dopaminergic neurons and the distribution and density of dopamine receptors, and are also related to the clinical effectiveness of levodopa therapy.

Aged↗

PubMed1992

Alteration of second-messenger ligand binding following 2-hr hemispheric ischemia in the gerbil brain.

The alterations of second-messenger ligand binding and cerebral blood flow (CBF) were evaluated in the gerbil brain after 2-h unilateral common carotid artery occlusion. [3H]Forskolin (FK) and [3H]phorbol-12,13-dibutyrate (PDBu) were used as specific ligands for adenylate cyclase (AC) and protein kinase C (PKC) activity estimation, respectively. CBF was determined at the end of the experiment by the [14C]iodoantipyrine method. A quantitative autoradiographic method permitted simultaneous measurement of the three parameters in the same brain. The levels in the caudate-putamen, globus pallidus, and hippocampus were analyzed. The animals were divided into three groups: Group 1 with severe ischemia (CBF in the lateral nuclei of the thalamus (CBFt) less than 50 ml/100 g/min), Group 2 with mild ischemia (CBFt greater than or equal to 50 ml/100 g/min), and the Sham Group. The PDBu binding revealed a statistically significant increase in the caudate-putamen, lateral nuclei of the thalamus and hippocampus (CA1 and CA3 regions and dentate gyrus) on the ischemic side in Group 1 as compared to that in Group 2 and the Sham Group. In contrast, the FK binding did not show any significant changes in any of the regions. These data and our previous findings for 6-h ischemia suggest that (1) PKC translocation to the cell membrane may occur at the early ischemic phase in particular regions including the caudate-putamen, lateral nuclei of the thalamus and hippocampus, with the translocated PKC gradually diminishing during the subsequent ischemic period; and (2) the suppression of the AC system observed in 6-h ischemia may not appear in the early ischemic phase.

Adenylyl Cyclases↗

PubMed1991

Inhibition of nitric oxide synthesis induces a significant reduction in local cerebral blood flow in the rat.

The effect of intravenous administration of NG-monomethyl-L-arginine (L-NMMA, 30 mg/kg), a specific inhibitor of nitric oxide synthesis, on local cerebral blood flow (lCBF) was examined in the rat using the [14C]iodoantipyrine autoradiographic method. L-NMMA induced a statistically significant reduction in lCBF in the cerebral cortices as well as in various deep structures of the brain. This reduction in lCBF was accompanied by a clear increase in mean arterial blood pressure, suggesting that the cerebral resistance vessels constricted significantly beyond the autoregulatory response following L-NMMA administration. These findings indicate that the basal cerebral circulation may be closely related to nitric oxide production.

Animals↗

PubMed1991

Nine Japanese patients with immotile-dyskinetic cilia syndrome: an ultrastructural study using tannic acid-containing fixation.

Respiratory cilia and sperm flagella of nine Japanese patients with immotile-dyskinetic cilia syndrome were studied ultrastructurally by using a tannic acid-containing fixative. Respiratory cilia from two female patients with Kartagener's syndrome and one male patient with situs inversus and sinobronchitis were completely immotile and lacked both dynein arms. However, approximately 30% of the spermatozoa from the male patient were weakly motile. In four patients with immotile cilia syndrome without Kartagener's triad, immotile respiratory cilia generally lacked the inner dynein arms. Two clinically unusual cases, an 11-year-old boy and a 29-year-old woman with prolonged saccharin test, recurrent bronchitis, and bronchiectasia, possessed motile respiratory cilia. Ultrastructurally, both dynein arms were normal, but numerous defective central pairs (more than 50% and 70%, respectively) were seen, and the defect in the second case was similar to the transposition of microtubules reported by Sturgess et al (N Engl J Med 303:318-322, 1980). However, defects in the first case were unique and may be congenital. We propose a new type of dyskinetic cilia syndrome with defective central pairs. Additionally, nasal cilia from a 35-year-old man with immotile cilia syndrome contained excess large singlets within ciliary axonemes consisting of 17 protofilaments.

Adult↗

PubMed1990

Chronic immune thrombocytopenia in sarcoidosis.

We report a 69 year-old female with sarcoidosis who developed chronic thrombocytopenia, a rare complication of this disorder. Histologically normal bone marrow with increased number of megakaryocytes and high level of PAIgG strongly suggest the immune destruction of platelets as the cause of thrombocytopenia. In addition to thrombocytopenia, this case is also distinctive in its clinical manifestation. The patient developed several infrequent manifestations of sarcoidosis including complete AV block, uveitis, skin eruptions and middle lobe syndrome, but, did not have an intrathoracic adenopathy, the commonest manifestation of this disease.

Aged↗

PubMed1989

[A case of anti-phospholipid antibody syndrome presenting chorea as an initial manifestation].

A 20 year old female patient with anti-phospholipid antibody syndrome who presented chorea as an initial symptom is described. At the age of 14, she noticed involuntary movements of upper and lower extremities bilaterally. The CT scan revealed the presence of low density areas in the right caudate nucleus and left putamen. The result of the laboratory tests included antibodies to nuclear antigens (positive FANA and anti-DNA), prolonged PT and APTT, biological false positive for syphilis. Her serum contained antibodies to cardiolipin and phosphatidylserine as demonstrated by specific ELISA assay method. The clinical diagnosis of chorea was made and haloperidol was administered with partial symptomatic improvements. The patient reported here is the first well documented case of anti-phospholipid antibody syndrome presenting chorea as an initial manifestation in the Japanese literature.

Adult↗

PubMed1989

[A case of immotile cilia syndrome and a review of Japanese cases].

A case of immotile cilia syndrome (ICS) is presented. A 34-year-old male, who had suffered from recurrent bronchitis, sinusitis and otitis media since early childhood, was admitted to Keio University Hospital complaining of productive cough and infertility. A saccharin test showed prolonged nasal clearance time, and semen analysis revealed immotile sperm. By electron microscopic observation of cilia of the nasal mucous epithelium and the sperm, inner and outer dynein arm defect, abnormal microtubular arrangement and compound cilia were detected and he was diagnosed as ICS. Thirty eight Japanese cases of ICS collected from the literature were analyzed concerning clinical manifestations, airway clearance, family history and ciliary ultrastructural abnormalities (Table 2, 3). Recurrent bronchitis, male infertility, chronic sinusitis, otitis and decrease in airway clearance were very common in these patients. Female infertility was more common than anticipated. The prevalence rate of situs inversus was more than 50%, probably due to more attention having been paid to Kartagener's syndrome in Japan. Recent studies show that the cilia of this syndrome is not always immotile but characterized by hypomotility or asynchrony, and have attempted to determine the relationship between each ciliary ultrastructural abnormality and motility pattern. It is necessary that more patients including incomplete and mild cases should be investigated.

Adult↗

PubMedDate not supplied

Expression of interleukin-6 in cerebral neurons and ovarian cancer tissue in Trousseau syndrome.

Interleukin-6 (IL-6) is reportedly increased in serum and CSF from acute stroke patients. However, the cellular origin and possible role of IL-6 in CNS after stroke are unclear. We describe a woman with recurrent stroke, disseminated intravascular coagulation (DIC) and non-bacterial thrombotic endocarditis (NBTE) caused by ovarian cancer (Trousseau syndrome). The patient died 50 days after the final episode of cerebral embolism. The immunohistochemical study revealed IL-6 protein to have been expressed both in cerebral neurons spared from ischemic insult and in epithelial cells of the ovarian tumor. We speculate that IL-6 produced in ovarian cancer may be associated with the hypercoagulable state and the development of NBTE in this patient. In contrast, IL-6 induction in cerebral neurons may contribute to the survival of these neurons after a stroke.

Coronary Thrombosis↗