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Biomedical subjects

S Murayama

Publications and source records attributed to S Murayama.

At least 181 records · Page 10Linked to original sources
PubMed1991

Radiographic changes in cardiac contours following heart transplantation. Clarification by MR imaging.

Chest radiographs of 46 patients who had undergone heart transplantation were reviewed with special attention to abnormalities of the cardiac contours. MR imaging in 3 such patients revealed 3 types of double right cardiac contours: the recipient right atrium combined with the donor right atrium; the donor right atrium combined with the recipient left atrium; and a cardiac fat pad combined with the right atrium. A prominent main pulmonary artery was shown by MR imaging to result from leftward displacement of the main pulmonary artery caused by clockwise rotation and transverse position of the transplanted heart. Recognition of these unique radiographic appearances is of value in assessing transplanted hearts and in avoiding misdiagnosis.

Adolescent↗
PubMed1991

[Coronary venous oxygen saturation dynamics during intracoronary infusion of ergonovine or acetylcholine in vasospastic angina].

We investigated changes in coronary venous oxygen saturation (CSO2-Sat) dynamics during intracoronary infusion of ergonovine (ERG) or acetylcholine (ACh) in patients with vasospastic angina. In 16 patients with suspected vasospasm in the left coronary artery, intracoronary ERG injection provoked vasospasm in 4 out of 6 patients, and intracoronary ACh in 6 out of 11 patients. A gradual decrease in CSO2-Sat, anteceding angina and ischemic ECG evidence, was characteristic in ERG-induced vasospastic patients, while no significant change of CSO2-Sat was observed in non ERG-induced patients. Intracoronary infusion of ACh was followed in all 11 patients by a transient increase in CSO2-Sat, suggesting decreased myocardial oxygen extraction due to increased coronary blood flow with ACh. However, earlier and sudden decreases in CSO2-Sat below the control levels were characteristic in 6 patients with ACh-induced vasospastic angina. These findings suggest that effects of ERG and ACh on coronary flow dynamics are essentially different although both drugs can provoke vasospasm.

Acetylcholine↗
PubMed1990

[Late radiation fibrosis in rat lung following protons and 250 kV X-rays irradiation].

To investigate the biological effectiveness of proton beams in the development of pulmonary fibrosis the lungs of male 7-week-old Wistar rats were locally irradiated with a single dose of 10-50 Gy of 250 kV X-rays and modulated, 250 MeV protons at Particle Radiation Medical Science Center (PARMS). Animals were sacrificed serially after 3, 6, 9 and 12 months at which times the development of the fibrotic lesion in alveolar walls and peribronchial connective tissues was assessed quantitatively by analysis of microscopic images of Azan-Mallory stained sections. Fibrosis index (FI) values in alveolar walls and peribronchial tissues were defined as the fraction (in percent) of a specific image area, the gray level of which represents collagen deposits. Using this FI values, the increase of fibrotic lesion following 0-40 Gy of X-rays irradiation as a function of time were observed better in alveolar walls than in peribronchial tissues. Compared with 250 kV X-rays, 30 Gy of proton beams irradiation produced less increase in the time course of FI values of alveolar walls and dose-response curve at 12 months later suggested that the fibrotic lesion in alveolar walls after protons exposure of the doses above 30 Gy might develop more slowly.

Animals↗
PubMed1990

Immunocytochemical and ultrastructural studies of lower motor neurons in amyotrophic lateral sclerosis.

Neuronal inclusions in lower motor neurons in 23 cases of adult-onset sporadic amyotrophic lateral sclerosis were studied immunocytochemically and ultrastructurally. Monoclonal and polyclonal antiubiquitin antibodies recognized four structures in the neuronal perikarya: (1) all Lewy body-like inclusions in 6 cases with a relatively short clinical course, (2) a small percentage of Bunina bodies in 4 cases with abundant Bunina bodies, (3) ill-defined structures closely associated with Bunina bodies (Bunina body-related structures) in 15 cases, and (4) a focally aggregated meshwork of fine filamentous structures not associated with Bunina bodies in all cases. These four structures were not recognized by the antibodies raised against cytoskeletal proteins (neurofilament, tubulin, microtubule-associated protein 2, and phosphorylated tau). Electron microscopy revealed Lewy body-like inclusions to be accumulations of randomly oriented filaments, approximately 15 nm in diameter, covered by fine granules. Bundles of coated filaments 12 nm in diameter that sometimes formed Bunina body-like structures were also observed in the perikarya. Immunoelectron microscopy showed the reaction product with antiubiquitin to be on the filaments, 15 nm in diameter, of Lewy body-like inclusions. Our study revealed the existence of two types of filaments in lower motor neurons of patients with amyotrophic lateral sclerosis: (1) ubiquitin-positive, granule-associated filaments, approximately 15 nm in diameter, that form Lewy body-like inclusions; and (2) 12 nm coated filaments that may be a candidate for another ubiquitin-positive structure and possibly a precursor of Bunina bodies. These two types of filaments may represent early pathological changes of lower motor neurons in amyotrophic lateral sclerosis.

Adult↗
PubMed1990

Immunocytochemical and ultrastructural studies of Pick's disease.

Cerebral cortical changes in 10 cases with Pick's disease were studied immunocytochemically and ultrastructurally. All cases contained Pick's argentophilic bodies and ballooned neurons. The antibodies against phosphorylated tau proteins that intensely stained all Pick bodies recognized numerous neuronal processes around Pick body-bearing cells and focal portions in the perikarya of ballooned neurons. Monoclonal and polyclonal anti-ubiquitin antibodies stained not only some Pick bodies with variable intensity, but also the perikarya of all ballooned neurons. Ultrastructurally, Pick bodies consisted of accumulation of randomly oriented, approximately 15-nm straight filaments and paired twisted profiles with a minimal diameter of 13 nm, maximal diameter of 26 nm, and twist periodicity of 120 nm. These Pick body-type filaments were also observed in the perikarya of ballooned neurons and neuronal processes around Pick body-bearing cells. Our studies demonstrate, for the first time, the characteristic pathological feature of neuropil in Pick's disease. Pick body-bearing cells and ballooned neurons show unique immunocytochemical and ultrastructural properties that may be a clue to the pathogenesis of Pick's disease.

Aged↗
PubMed1990

Selective sparing of Betz cells in primary motor area in hypoxic-ischemic encephalopathy.

Two cases of postoperative hypoxic-ischemic encephalopathy are described in which Betz cells of the primary motor area were selectively spared. In one patient the hypoxic-ischemic encephalopathy led to a vegetative state and in the other patient to a spastic quadriparesis and cortical blindness. In contrast to the relative sparing of Betz cells, Purkinje cells of the cerebellar cortex were totally destroyed. These two cases suggest that Betz cells are relatively resistant to hypoxic-ischemic insult under certain conditions.

Adult↗
PubMed1990

MR imaging of pancreas in cystic fibrosis.

The pancreatic regions of 18 patients with cystic fibrosis were analyzed with a 1.5 Tesla MR unit. Signal intensity of the pancreas was correlated with clinical data and ultrasound. A hyperintense pancreas on T1-weighted image was consistent with fatty replacement of pancreatic insufficiency. A pancreas of normal soft tissue intensity was found in two asymptomatic and one symptomatic patient. A very hypointense pancreas on any pulse sequence was considered to be an intermediate stage of pancreatic degeneration.

Adolescent↗
PubMed1990

Degenerative lumbar spine disorders in gradient refocused echo axial magnetic resonance images.

The axial images of 58 lumbar disks having degenerative disorders imaged by gradient refocused echo (GRE) and spin echo (SE) magnetic resonance imaging (MRI) pulse sequences at high field strength were compared for diagnostic quality. The vacuum phenomenon, calcified disk, and bony hypertrophic changes were better demonstrated by GRE images than by SE images due to magnetic susceptibility effect. Axial GRE images are therefore useful adjuncts to SE images for effective MRI of degenerative lumbar spine disorders at high field strength.

Humans↗
PubMed1990

Transposon insertion mutagenesis of a genetic region encoding serum resistance in an 80 kb plasmid of Salmonella dublin.

Using transposon insertion mutagenesis with Tn1 or Tn5, we obtained Salmonella dublin mutant strains that showed either diminished serum resistance (five mutants) or diminished mouse lethality (two mutants). Detailed restriction cleavage analysis to determine the single sites of transposon insertion in an 80 kb plasmid (pTE800) indicated that a region for serum resistance was located within a 3.0 kb region of the SalI cleavage fragment 5 and the HindIII fragment 2, while the region for mouse lethality was within a 6.0 kb region of the SalI fragment 2 and the HindIII fragment 1. When the Tn1-containing SalI fragment 5 was reconverted, by homologous recombination, to the original SalI fragment 5 (9.6 kb), serum resistance was recovered to the same level as that of a parent strain 52401. Moreover, the change in the serum resistance correlated with changes in the neutral sugar composition of the LPS. The mutation in the plasmid in strain TE4-55 that gave diminished mouse lethality was also reversed by recombination with the cloned SalI fragment 2 (15.0 kb), with concomitant recovery of mouse lethality. These results indicate that the genetic region for serum resistance is different from that for mouse lethality, and that the gene for serum resistance is closely involved with the expression of the neutral sugar composition of the LPS of S. dublin.

Animals↗
PubMed1990

Paraneoplastic encephalomyelitis. An autopsy case with encephalitis principally confined to the thalamus and associated with pulmonary and gastric cancers.

We report an autopsy case of encephalitis principally confined to the bilateral thalamus and associated with pulmonary and gastric cancers. An 81-year-old man exhibiting behavioral abnormalities and progressive somnolence died of pneumonia 11 months after onset. Because the patient had lung cancer and no definite cause of the encephalitis was found, this case was categorized as one of paraneoplastic encephalomyelitis. This may be the first reported case of this condition in which the central nervous system (CNS) lesion was located predominantly in the thalamus.

Aged↗
PubMed1990

Bronchopulmonary sequestration: CT assessment.

Computed tomographic (CT) scans of 24 bronchopulmonary sequestrations in 23 patients were reviewed. Seventeen sequestrations were diagnosed at surgery, three at angiography, and four on the basis of radiographic or CT findings combined with appropriate history. Sixteen sequestrations were intralobar, and eight were extralobar; 21 were posterobasal. Seventeen occurred on the left side and seven on the right. Anomalous systemic arterial supply was demonstrated by CT in 16 sequestrations. In the others, a systemic artery was not shown, presumably because of unfavorable orientation or small size of the vessel. The lung abnormalities shown by CT were classified into three types: A = cysts containing air or fluid (n = 8), or soft-tissue masses (n = 2); B = emphysematous lung surrounding cysts, and/or soft-tissue nodules (n = 13); and C = lung hypervascularity (n = 2). In only three cases did the chest radiograph show the emphysematous lung tissue. Such emphysematous lung has rarely before been reported as a CT finding, and lung hypervascularity has not, to the authors' knowledge, been reported. The authors conclude that CT can be helpful in the diagnosis and evaluation of bronchopulmonary sequestration. Characteristic manifestations are (a) a complex lesion containing solid or fluid components combined with emphysematous lung or (b) any basal lesion supplied by a systemic artery.

Adolescent↗
PubMed1990

Whipple's disease presenting with isolated neurological symptoms. Case report.

Whipple's disease is infrequently considered in the differential diagnosis of patients presenting with progressive neurological deterioration. This is in part a result of the relative rarity of this entity and in part due to the more frequent initial presentation of the disease with gastrointestinal, musculoskeletal, or cardiovascular symptoms. A case is described in which the neurological symptoms of progressive dementia and weakness were seen in the relative absence of non-neurological symptomatology. The diagnosis of Whipple's disease was made from a brain biopsy. The neuropathology of Whipple's disease of the central nervous system is described and the importance of considering it as a treatable entity in the differential diagnosis of progressive neurological deterioration, despite the absence of systemic symptomatology, is stressed.

Biopsy↗
PubMed1990

Analysis of left ventricular diastolic function by the pressure-volume relation in cases with idiopathic restrictive cardiomyopathy and amyloid restrictive cardiomyopathy.

To assess left ventricular (LV) diastolic function in idiopathic restrictive cardiomyopathy (IRCM) and amyloid restrictive cardiomyopathy (ARCM), we analyzed LV cineangiograms and pressures (tip manometer) in two patients, one with IRCM and the other with ARCM. LV volume and instantaneous rate of change of volume were derived from frame-by-frame analyses of angiograms. LV relaxation was assessed by the time constant of isovolumic pressure decay. LV compliance was evaluated by the pressure-volume relationship. From these analyses, we conclude as follows: (1) In restrictive cardiomyopathy (RCM), LV diastolic dysfunction may be characterized by impaired relaxation and decreased compliance; (2) LV diastolic filling was minimally impaired or normal in both conditions; (3) The ventricular diastolic pressure wave form of "dip and plateau" seemed not to be a characteristic sign in RCM.

Blood Pressure↗