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Biomedical subjects

S Ohkawa

Publications and source records attributed to S Ohkawa.

At least 55 records · Page 3Linked to original sources
PubMed1998

Histological evidence for cell proliferation activity in cystic tumor (endodermal heterotopia) of the atrioventricular node.

Cystic tumor (endodermal heterotopia) of the atrioventricular (AV) node in a 95-year-old female is described. Electrocardiograms showed complete AV blockage with a narrow QRS morphology resulting from the long-standing first degree of AV blockage since age 61. A cardiac pacemaker was implanted at age 83. The patient died of pneumonia at age 95. Autopsy demonstrated a normal heart weight (320 g), normal coronary artery and normal myocardium. Histological examination of the conduction system revealed a marked fibrotic sinoatrial (SA) node and a cystic lesion in the lower right atrium, including the approaches to the AV node. The bundle of His and its branches were completely intact. Cellular nests and cystically dilated tubules were scattered within a loose tissue stroma, which measured 18 x 12 x 5 mm. There were several mitotic figures among the tubules, as well as nuclear fragments similar to apoptotic bodies and exfoliation of the tumor cells. Immunohistochemical studies demonstrated a positive reaction for epithelial membrane antigen, carcinoembryonic antigen, CA19-9, cytokeratin and secretory component in the tubular cells, and a negative reaction for thrombomodulin. Endocrine cells among the tubules were positive only for calcitonin and serotonin. Ultrastructurally, sparse microvilli and desmosome-like structures between the tumor cells were observed. These findings support that this lesion originates from the endoderm. Moreover, it is likely that progression in the degree of AV block may be explained by the cell proliferation activity of the tumor.

Aged↗
PubMed1997

7-Spiroindanyl derivatives of naltrexone and oxymorphone as selective ligands for delta opioid receptors.

A series consisting of spiroindanyl (5-7), benzospiroindanyl (8-10), and spiroperinaphthyl (11) derivatives of naltrexone and oxymorphone were synthesized in order to investigate the role of an orthogonal-oriented "address" for delta opioid receptors. All of the ligands exhibited a preference for delta receptors in vitro. The 7-benzospiroindanyl derivative 8 (BSINTX) was the most selective delta opioid receptor antagonist in vitro. In mice BSINTX antagonized the delta 1-selective agonist, [D-Pen2,D-Pen5]enkephalin without significantly affecting the antinociceptive potency of delta 2, mu, and kappa agonists. The results of this study are consistent with an orthogonally-oriented address favoring delta 1 activity.

Analgesia↗
PubMed1997

Relationship between the recurrence of hepatocellular carcinoma (HCC) and serum alanine aminotransferase levels in hepatectomized patients with hepatitis C virus-associated cirrhosis and HCC.

BACKGROUND: The relationship between the recurrence of hepatocellular carcinoma (HCC) and the serum alanine aminotransferase (ALT) level was studied in hepatectomized patients with hepatitis C virus (HCV)-associated cirrhosis and HCC. METHODS: Twenty-six hepatectomized patients with HCV-associated cirrhosis and HCC whose resected specimens showed neither portal vein nor hepatic vein invasion by HCC histologically were divided into 2 groups: 15 patients who had no recurrence 3 years after surgery (Group A) and 11 patients whose disease recurred 1-3 years after surgery (Group B). The patients' serum ALT levels during this period were examined. RESULTS: In Group A, serum ALT generally showed sustained low levels < 80 international units (INU) in 12 patients (80%). In contrast, ALT levels in Group B showed several peaks or plateaus > 80 INU in all patients except 2. The recurrence rate of HCC in the hepatectomized patients with sustained low levels of ALT was 14.3% (2 of 14 patients) at 3 years, and was significantly lower (P < 0.01) than that in those patients whose ALT levels showed several peaks or plateaus > 80 INU (9 of 12 patients; 75.0%). The average level of mode of ALT in Group A (48.8 +/- 26.0 INU) was significantly smaller than that in Group B (101.1 +/- 47.3 INU) (P < 0.005). CONCLUSIONS: The importance of hepatocytic necrosis in the recurrence of HCC in hepatectomized patients with cirrhosis and HCC of HCV origin was demonstrated and the significance of subsiding hepatic necroinflammatory process in the prevention of HCC recurrence suggested.

Aged↗
PubMed1997

5-aminocoumarans: dual inhibitors of lipid peroxidation and dopamine release with protective effects against central nervous system trauma and ischemia.

A series of 2,3-dihydro-5-benzofuranamines (5-aminocoumarans) were developed for the treatment of traumatic and ischemic central nervous system (CNS) injury. Compounds within this class were extremely effective inhibitors of lipid peroxidation in vitro and antagonized excitatory behavior coupled with peroxidative injury induced by spinal intrathecal injection of FeCl2 (mouse-FeCl2-it assay) in vivo. Selected compounds were tested for antagonistic activity on methamphetamine (MAP)-induced hypermotility resulting from dopamine release in the mouse brain. Among the compounds synthesized, compound 26n (2,3-dihydro-2,4,6,7-tetramethyl-2-[(4-phenyl-1-piperidinyl) methyl]-5-benzofuranamine) exhibited potent effects in these assays (inhibition of lipid peroxidation, IC50 = 0.07 microM; mouse-FeCl2-it assay, ID50 = 10.4 mg/ kg, po; MAP-induced hypermotility, 98% inhibition, 10 mg/kg, ip). The S-(+)-form of compound 26n dihydrochloride (TAK-218), which has 30 times more potent antagonistic activity on MAP-induced hypermotility than the R-(-)-form, improved more significantly the survival rate in the cerebral ischemia model (rat, 1-3 mg/kg, ip) during the period of 1-14 days after ischemia and decreased functional disorders in the traumatic brain injury model (rat, 0.1-1 mg/kg, ip) 3-14 days after injury. These results imply a role for dopamine in deterioration of CNS function after ischemic and traumatic injury. TAK-218 is a promising compound for the treatment of stroke and CNS trauma and is now under clinical investigation.

Animals↗
PubMed1997

[Trend of bacterial meningitis in children over a 14 year period (1981 through 1994) in Japan--an analysis based on studies in 27 institutions].

We observed 266 children with purulent meningitis in 27 institutions in Japan during the 14 years from 1981 on dividing these years into 3 periods, 1981-1985, 1986-1990 and 1991-1994, and studied the trend of causative organisms identified in 254 among the 266 patients. Their ages were less than 3 months after birth in 50 children and 3 months or older in 216: there were 141 boys and 125 girls. The causative organisms were H. influenzae in 134 patients and S. pneumoniae in 50, most of them being aged 3 months or older. Next to the above bacteria ranked S. agalactiae in 29 and E. coli in 12, many of the patients were aged less than 3 months. Staphylococcus spp. was found in 7 patients and about 70% of them were aged 3 months or older. L. monocytogenes was found in 4 patients and N. meningitidis in 3 and they were aged 3 months or older in both patient groups. S. pyogenes, Enterococcus spp., Peptostreptococcus spp., P. Mirabilis and Enterobacter spp. were detected each in 1 patient. The causative organism was unknown in 21 patients and there was no double infection. H. influenzae were detected in 18 patients in 1981-1985 period (36.7%), in 56 in 1986-1990 (54.9%) and in 60 in 1991-1994 (63.8%) showing an increasing tendency, but S. pneumoniae exhibited neither an increasing nor decreasing tendency. There was a decreasing tendency with S. agalactiae and E. coli, but the details were not clear because there were few patients aged less than 3 months. Although the period of coexistence of 4 main bacterial species was not made clear in this study. Listeria is considered to develop mainly in the early childhood, and we believe that the conventional way of using a cephem preparation and ampicillin combined for patients under 6 years need not be altered. However, panipenem (phonetic) is likely to be effective for insensible S. pneumoniae for the time being.

Escherichia coli↗
PubMed1997

A case of primary malignant fibrous histiocytoma of the heart with a left-to-right atrial shunt.

A previously healthy 64-year-old woman attended our hospital with chest pain, facial edema, and general fatigue. A chest radiograph revealed cardiomegaly, small bilateral pleural effusions, and hilar congestion--findings that improved after early therapy with furosemide and methyldigoxin. A chest radiograph recorded 7 years earlier had revealed no dilation of cardiac shadow. There were no findings suggesting atrial septal defect (ASD) or valvular heart disease. Echocardiography revealed a tumor-like mass adhering to the posterior wall of the left atrium. Color-flow Doppler echocardiography revealed a left-to-right shunt at the atrial level. The Qp/Qs ratio as measured by cardiac catheterization was 2.0. Coronary angiography revealed abnormal dilated arteries from the atrioventricular nodal branch and several feeding arteries from the left circumflex branch. We hypothesized that the left-to-right shunt could be due to the tumor, which extended to the rim of the patent foramen ovale, or to the very small, previously unrecognized, ASD. This patient died 6 months after her first admission and an autopsy was performed. Light microscopic examination of the tumor revealed spindle-shaped fibroblast-like cells arranged in a storiform or fascicular pattern. The immunohistochemical findings were consistent with malignant fibrous histiocytoma (MFH). In the literature, left-to-right shunt at the atrial level has not been reported in patients with cardiac MFH.

Echocardiography↗
PubMed1997

[Relation of asymptomatic myocardial ischemia to impaired communication, cerebrovascular disease, and lack of ability to perform activities of daily living in elderly patients].

Patient's reports of angina pectoris depend on cognition and communication, and on the patient's physical and mental activity. In elderly people, these functions are often impaired, and we therefore looked for evidence of myocardial ischemia in 770 consecutive autopsies. We defined the coronary stenosis index (CSI) as the sum of the stenosis scores of three coronary arteries: 0% = 1, 25% = 2, 50% = 3, 75% = 4, 90% = 4.5 95 or 100% = 5. A total score of more than 13.0 and a score of 5.0 in one vessel was assumed to have been associated with myocardial ischemia. Patients assumed to have had myocardial ischemia were classified according to the presence or absence of angina pectoris: 24 had angina pectoris and 92 were asymptomatic. As controls, 86 patients in whom the CSI was lower than 10.0 were studied. Death due to myocardial infarction was most frequent in patients with angina (67%). Acute myocardial infarction was more common in asymptomatic patients than in controls (27% vs. 1%). Small myocardial infarctions and inferior myocardial infarctions were more frequent in asymptomatic patients than in those with angina. Cerebrovascular disease, problems doing activities of daily living, and communication disturbance were more common in asymptomatic patients than in those with angina. Electrocardiographic evidence of an old myocardial infarction was found in 40.9%, 16.6%, and 2.3% of patients with angina, asymptomatic patients, and controls, respectively (p < 0.05). Morphologic details of the myocardial infarction, coexistence of cerebrovascular disease, inability to perform activities of daily living, and impaired communication are associated with asymptomatic myocardial ischemia. Patients with asymptomatic myocardial ischemia should be identified and treated because of their relatively poor prognosis. Ischemic events might be detected by careful observation and prevented by appropriate treatment.

Activities of Daily Living↗
PubMed1997

["Forced mouth opening reaction" associated with corticobasal degeneration].

Corticobasal degeneration (CBD) is a slowly progressive disorder characterized by an asymmetrical akinetic-rigid syndrome, supranuclear ophthalmoplegia, dystonia, often accompanied by involuntary movements, particularly myoclonus, and associated with lateralized cortical signs such as alien limb behavior and apraxia. Computerized tomography demonstrates asymmetrical frontoparietal cortical atrophy in the later stages of the illness. Neuropathological examination reveals neuronal loss, gliosis and swollen achromatic neurons within the frontal and temporal cortices, and the substantia nigra. We discuss here a unique phenomenon not described so far in three patients with clinical features of CBD, one with subsequent autopsy observations. When awake, they all showed a common behavior, their mouth opened constantly and immediately, when a tongue-depresser was approached in front of it by the examiner. In two of them, their mouth also opened when its corner was stroked by a tongue-depressor. They could not control these phenomena at all, even they were asked not to open their mouth. We would like to call these phenomena "forced mouth opening reactions" because they were uncontrollable voluntarily. They may be divided into two groups, i.e. visual and tactile "forced mouth opening reactions". In all the patients the neurological, neuro-imaging and neuropathological data showed that the frontal lobes were damaged. Additionally, they had some frontal lobe release signs such as forced grasping, forced groping, or alien limb sign. We would like to apply the mechanism for these release signs to the "forced mouth opening reactions". Thus, we speculate that the frontal lobe contains a higher motor control mechanism for normal mouth opening movement, and the "forced mouth opening reactions" result from impairment of this control.

Basal Ganglia Diseases↗
PubMed1996

Pathologic implications of restored positive T waves and persistent negative T waves after Q wave myocardial infarction.

OBJECTIVES: We sought to study the pathologic implications of restored positive T waves and persistent negative T waves in the chronic stage of Q wave myocardial infarction. BACKGROUND: Some inverted T waves (coronary T waves) become positive after acute myocardial infarction; others retain their negative T wave component for a long time. The pathologic implications of the difference between restored positive T waves and persistent negative T waves in leads with Q waves has not, until now, been given much careful study. METHODS: Of 17 patients with anterior or anteroseptal myocardial infarction confirmed by autopsy, 8 (group P) had positive and 9 (group N) had negative T waves in precordial leads with Q waves > or = 1 year after the onset of myocardial infarction. The appearance and extent of the infarct area and the degree of coronary artery stenosis were evaluated in both groups. RESULTS: At autopsy, seven of eight patients in group P had nontransmural fibrotic changes in the anteroseptal or anterior wall. However, seven of nine patients in group N had a transmural myocardial infarction consisting of only a thin fibrotic layer in the anteroseptal or anterior wall. The left anterior descending coronary artery showed 75% stenosis in 1 patient in each group but > 90% stenosis in the remaining 15 patients. CONCLUSIONS: Persistent negative T waves in leads with Q waves in the chronic stage of myocardial infarction indicate the presence of a transmural infarction with a thin fibrotic layer, whereas positive T waves indicate a nontransmural infarct containing viable myocardium within the layer.

Aged↗
PubMed1996

Myocardial viability in cases with persistent perfusion defects on the dipyridamole thallium-201 scintigram. A comparative study with autopsy findings.

The aim of this study was to assess the incidence of myocardial infarction among persistent perfusion defects in dipyridamole-stress thallium scintigraphy by inspecting autopsied hearts and to evaluate whether the regional thallium activity of a scintigraphic defect can predict the presence of infarction. Autopsied hearts were compared with dipyridamole myocardial scintigrams undertaken during life in 27 patients (mean age 85 +/- 8 years). The time interval from stress testing until death was 428 +/- 351 days. Regional thallium uptake of delayed perfusion defect was calculated on the short axis images. The grade of regional myocardial fibrosis in autopsy specimens was also quantified to correlate with the corresponding regional thallium uptake. In 6 of 15 (40%) regions with persistent defects on the scintigram, myocardial infarction was not found at autopsy. Regional thallium-201 uptake of delayed defects < 50% diagnosed infarction with a sensitivity of 82% and a specificity of 80%. A linear correlation (r = -0.67) was observed between percent thallium-201 uptake and the degree of myocardial fibrosis. In conclusion, perfusion defects at 4-hour imaging in dipyridamole-stress testing may overestimate the presence of myocardial infarction and regional thallium-201 activity is helpful in distinguishing between defects with and without infarction.

Aged↗
PubMed1996

[The relationship between office and ambulatory blood pressure in elderly patients in a non-academic setting].

We investigated the relationship between clinic blood pressure (BP) and ambulatory blood pressure (ABP) in 297 elderly patients who underwent 24 hour ABP monitoring as a non-academic clinical references. Among 107 cases who were normotensive in office BP measurements, 33 cases (30.8%) proved to be hypertensive with more than 140 mmHg in ambulatory systolic BP. Those patients should be referred to as home hypertension or white coat normotension. On the other hand, among 187 patients who were hypertensive in the clinic, 78 cases (41.7%) turned out to be white coat hypertension with an ambulatory daytime systolic BP of less than 140 mmHg. Ambulatory systolic BP in white coat hypertension was comparable with that in the non-hypertensive group although their BP in the clinic was significantly higher than the latter (p < 0.02). Ambulatory systolic BP in the home hypertension group was significantly higher than that in the normotension but was comparable with that in true hypertension. The number of the antihypertensive drugs prescribed in the white coat hypertensive group tended to be greater than that in other groups although that in the home hypertensive group was similar to the other groups. The incidence of cerebro vascular disease in each group was similar.

Aged↗
PubMed1996

[Clinicopathologic study of mitral regurgitation due to abnormal chordae tendineae].

Severe mitral regurgitation (MR) due to abnormal chordae tendineae as a primary cause is rare. This clinicopathologic study included four such cases which occurred among 6,500 consecutive autopsies on persons older than 60 years. This paper describes three of these cases. Case 1 was a 76-year-old woman with congestive heart failure, MR and atrial fibrillation. She died of acute myocardial infarction. The heart weighed 360 g. Mitral regurgitation was caused by a thick and long abnormal chorda originating from the posteromedial papillary muscle and protruding into the atrial surface of the middle scallop of the posterior mitral leaflet associated with prolapsed anterior mitral leaflet. Case 2 was an 81-year-old woman with MR and congestive heart failure. She died of acute myocardial infarction. The heart weighed 480 g. There were abnormal chordae tendineae with very few branches at the posterior commissure. Parts of both mitral leaflets on the sides of posterior commissure were also prolapsed. Case 3 was a 91-year-old man with MR and atrial fibrillation. He died of congestive heart failure. The heart weighed 530 g. Abnormal chordae tendineae with reticular structures originated from the anterolateral papillary muscle and protruded into the anterior mitral leaflet, which induced severe MR. These cases had abnormally protruding chordae tendineae, abnormal branching, and abnormal structures of the chordae tendineae, respectively. These abnormal chordae tendineae were considered to be congenital anomalies. Clinically all patients had a holosystolic murmur (Levine III-IV degrees), refractory congestive heart failure and atrial fibrillation. The etiology of the MR in these three patients was suspected to be ruptured chordae tendineae demonstrated on echocardiograms. These patients had heavy hearts (mean 457 g) with enlarged left atria and thickened mitral valves, which corresponded to the appearance of severe MR.

Aged↗
PubMed1996

[Trigeminal motor paralysis and dislocation of the temporo-mandibular joints].

A 64-year-old woman with diabetes mellitus was admitted to our hospital with left hemiparesis of sudden onset. A brain MRI demonstrated a cerebral infarction in the ventral part of the right lower pons. When left hemiparesis worsened, she had dislocation of the temporo-mandibular joints repeatedly. Then, her lower jaw deviated to the right when she opened her mouth. Also, there was decreased contraction of the right masseter when she clenched her teeth. These findings suggest that there was trigeminal motor paralysis on the right side resulting from involvement of the intrapontine trigeminal motor nerve. She has no history of dislocation of the temporo-mandibular joints. An X-ray film showed that the temporo-mandibular joints were intact. Thus, it is possible that deviation of the lower jaw was the cause of this dislocation. We suspect that dislocation of the temporo-mandibular joints may occur as a complication of unilateral trigeminal motor paralysis. This has not been reported to our knowledge.

Cerebral Infarction↗