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Biomedical subjects

S Murayama

Publications and source records attributed to S Murayama.

At least 73 records · Page 4Linked to original sources
PubMed1998

Progressive aphemia in a patient with Pick's disease: a neuropsychological and anatomic study.

We describe a patient with progressive aphemia with agrammatism that was later overlaid with buccofacial apraxia and pseudobulbar palsy. Pathological findings were consistent with those of classic Pick's disease with argyrophilic inclusions and neuronal achromasia, except for restricted cortical atrophy in the frontal operculum posterior to the pars opercularis (Brodmann Area 44). In addition, major neuronal loss was confined to the premotor cortex and the anterior half of the precentral gyrus (Area 6), which apparently explained the aphemia. The present case demonstrated that classic Pick's disease can show quite limited cortical atrophy in a patient who clinically presents with progressive aphemia. Also, our patient differed from the progressive non-fluent aphasia patients reported as having Pick's disease, who were all Pick variants, revealing that classic Pick's disease can be included in the spectrum of progressive aphasia syndrome.

Aphasia, Broca↗
PubMed1998

Enhancement of the Nipple-Areolar-Complex on Contrast-Enhanced MR Imaging of the Breast.

OBJECTIVE: To evaluate patterns of enhancement in the nipple-areolar-complex (NAC) on contrast-enhanced MRI. METHODS: We reviewed the MR images of 37 patients in which enhancement of the NAC was demonstrated on gadolinium-enhanced dynamic fast radiofrequency spoiled gradient recalled echo (fast-SPGR) images. Time intensity profiles derived from signal intensity values were constructed, and findings correlated with histological results. RESULTS: Three types of curve were observed. In the first type seen in adenoma of the nipple, rapid initial increase in signal intensity with an early peak (1 min) occurred followed by gradual washout. In the second type seen in direct invasion from carcinoma, subareolar intracystic papilloma, or Paget's disease, rapid initial increase in signal intensity followed by a more gradual increase or plateau was seen. In the third type seen in carcinoma without nipple invasion, fibrocystic disease and fibroadenoma, a gradual increase in signal intensity was observed throughout the examination period. CONCLUSION: Early and prominent enhancement of the NAC on contrast-enhanced MRImay indicate the presence of a primary lesion in the NAC or secondary involvement by a primary tumor elsewhere in the breast.

Journal Article↗
PubMed1998

Mechanism of short-term memory and repetition in conduction aphasia and related cognitive disorders: a neuropsychological, audiological and neuroimaging study.

To evaluate the role of the sub-cortical white matter and cortical areas of the supramarginal gyrus in short-term memory impairment (shortened digit or letter span) and repetition difficulty, four patients with conduction aphasia and impaired short-term memory and two patients with only short-term memory impairment were given digit span, letter span, speech audiometry and dichotic listening tests. The results showed that in most of the patients letter span was inferior to digit span and that bilateral ear suppression in the dichotic listening test was observed in two patients with a lesion in the inferior part of the supramarginal gyrus, suggesting that what was affected was phonological information and that the supramarginal gyrus was the storage site. The overlapped lesion of conduction aphasia patients with short-term memory impairment was the periventricular white matter at the upper to middle part of the trigone, while patients with only short-term memory impairment had a lesion in the inferior supramarginal gyrus in common. Thus, damage to the periventricular white matter at the trigone may yield the phonemic paraphasia characteristic of conduction aphasia, while damage to the inferior part of the supramarginal gyrus may result in the impairment of short-term memory. We believe that as a part of the mechanisms of short-term memory and repetition, phonological information is processed in the primary auditory cortex and goes through the periventricular white matter to the inferior part of the supramarginal gyrus and is temporarily stored there.

Aged↗
PubMed1998

Two types of chicken 2',5'-oligoadenylate synthetase mRNA derived from alleles at a single locus.

We have isolated two types of chicken 2',5'-oligoadenylate synthetase cDNAs, A and B, which encode predicted proteins of 508 amino acids (58316 Da) and 476 amino acids (54336 Da), respectively. The region of A-protein comprising 33 amino acid residues from 385Ala to 417Cys is substituted by a single amino acid 385Tyr in B-protein. The homology between chicken and mammalian 2',5'-oligoadenylate synthetases is 49.5% over the amino-terminal 337 residues. Proteins expressed from A- and B-cDNAs in E. coli cells were both active in synthesizing 2',5'-oligoadenylate. However, the activity of B-protein was 10-15% of that of A-protein. Southern blotting hybridization indicated that the chicken synthetases are encoded by a single gene. RT-PCR and PCR analyses of RNA and DNA of chicken erythrocytes together with the sequence data of the PCR products showed that A- and B-mRNAs are derived from alleles at a single locus encoding chicken 2',5'-oligoadenylate synthetase, designated as OAS * A and OAS * B. Chickens carrying OAS * A/B produce two types of synthetase with molecular masses of 58 and 54 kDa, and those carrying OAS * A/A produce only a single type of 58 kDa.

2',5'-Oligoadenylate Synthetase↗
PubMed1998

A genetic locus susceptible to the overt proteinuria in BUF/Mna rat.

The BUF/Mna (BUF) strain is a high-proteinuria line of rats, and virtually all rats develop overt proteinuria by the age of 20 weeks. Genetic analysis revealed that proteinuria susceptibility was determined principally by two autosomal recessive genes. These findings prompted us to perform genetic mapping of the genes. (BUF/Mna x WKY/NCrj) F1 x BUF/Mna backcross rats were raised and maintained for 40-60 weeks to detect proteinuria. DNAs were extracted from ears of these rats and were examined by linkage study with polymerase chain reaction (PCR) with 132 microsatellite markers. Fifty-three out of 167 rats developed proteinuria. DNAs of 51 out of these 53 rats showed homozygous BUF/BUF genotype in the D13Mgh4 and D13N1 markers located on Chromosome (Chr) 13. The D13Rat1, D13Mgh2, D13Rat13, D13Mgh3, Syt2, Ren, D13Rat25, D13Mit2, D13Mgh5, and D13N2 markers located on the chromosome also showed statistically significant linkage to the development of proteinuria, whereas the other 110 markers showed no linkage. Here we report that a proteinuria-susceptible gene, Pur1, resides on a region flanked by the loci D13Mgh3 and D13Mgh4 on Chr 13.

Animals↗
PubMed1998

Astrocytic plaques and tufts of abnormal fibers do not coexist in corticobasal degeneration and progressive supranuclear palsy.

Corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) are characterized by their unique clinical features and neuronal pathology. Although astrocytic plaques and tufts of abnormal fibers have been suggested to be specific histopathologic markers, recent studies have revealed significant clinicopathologic overlap between CBD and PSP. Based on the distinctive camera lucida profile of astrocytic inclusions on Gallyas-Braak silver staining, we found that astrocytic plaques and tufts of abnormal fibers did not coexist in the same patient among 30 cases of clinically diagnosed CBD, PSP and atypical Parkinson's disease. Using Tau immunohistochemistry it was difficult to verify the absence of tufts of abnormal fibers. A morphometric analysis revealed that the two groups classified by the presence or absence of astrocytic plaques and tufts of abnormal fibers exhibited significant differences in the density of ballooned neurons and neurofibrillary tangles and degeneration of the subcortical nuclei. Assessment using the NINDS neuropathologic criteria revealed that the cases with astrocytic plaques and tufts of abnormal fibers closely correspond to CBD and typical PSP, respectively. In addition, the cases lacking either of these two astrocytic inclusions had atypical PSP according to the NINDS criteria, and were associated with novel tau-positive astrocytes (spiny astrocytes). We thus conclude that astrocytic plaques and tufts of abnormal fibers are highly characteristic structures for CBD and typical PSP, respectively. We emphasize the importance of strict differentiation between different astrocytic inclusions not only for diagnosis, but also for further studies for elucidation of their role in the disease mechanisms of CBD and PSP.

Aged↗
PubMed1998

Lewy body in neurodegeneration with brain iron accumulation type 1 is immunoreactive for alpha-synuclein.

In familial PD, a mutation of the alpha-synuclein gene has been identified. Alpha-synuclein also was revealed in Lewy bodies in idiopathic PD. Lewy bodies in neurodegeneration with brain iron accumulation type 1 (NBIA 1; Hallervorden-Spatz syndrome) were found to show immunostaining for alpha-synuclein/precursor of non-A beta component of Alzheimer's disease amyloid, indicating that alpha-synuclein is commonly associated with the formation of Lewy bodies in other sporadic and familial neurodegenerative diseases apart from PD.

Adult↗
PubMed1998

Distal sensory axonopathy after sarin intoxication.

A 51-year-old man inhaled sarin during a terrorist attack on the Tokyo subway system and died 15 months later. Neuropathologic examination revealed marked nerve fiber decrease in the sural nerve, moderate nerve fiber loss in the sciatic nerve, and unremarkable dorsal root ganglia, dorsal roots, and posterior column of the spinal cord. This pathology is consistent with dying-back degeneration of the peripheral nervous system and could represent a late sequela of sarin intoxication.

Fatal Outcome↗
PubMed1997

Morphologic difference of neuropil threads in Alzheimer's disease, corticobasal degeneration and progressive supranuclear palsy: a morphometric study.

Using Gallyas-Braak's silver stain, neuropil threads (NTs) in Alzheimer's disease (AD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) were analyzed morphologically and morphometrically. The NT density was highest in the cerebral cortical layer V in AD and CBD, and in the subcortical white matter in PSP. An overlaid, two-dimensional, camera lucida drawing revealed differences in the fine profile of NTs among these three disease groups. The differences were confirmed by computerized feature analysis which revealed differences in maximum length, breadth, Feret's angle and orientation of the NTs. Unlike a previous assumption that all NTs have a similar appearance, our study revealed that NTs in AD, CBD and PSP were distinctively different with respect to their morphology.

Aged↗
PubMed1997

A Japanese family carrying a novel mutation in the Emery-Dreifuss muscular dystrophy gene.

We report on a Japanese family affected by Emery-Dreifuss muscular dystrophy carrying a novel mutation of the emerin (STA) gene. The cardinal clinical feature of the family was cardiac conduction block and mild myopathy. A deletion of 11 bp with a frameshift was identified in exon 6, causing truncation of the predicted protein. The relationship between mutation and phenotype is discussed.

Adolescent↗
PubMed1997

Expression of the copper-zinc superoxide dismutase gene in amyotrophic lateral sclerosis.

The demonstration of a genetic linkage between the copper-zinc superoxide dismutase (SOD1) gene and familial amyotrophic lateral sclerosis has aroused interest in the role of SOD1 in motoneuronal death. We investigated the expression of the human SOD1 gene at a cellular level in the motoneurons of patients with sporadic amyotrophic lateral sclerosis, patients with familial amyotrophic lateral sclerosis, and normal control subjects, using a quantitative in situ hybridization technique. There were no significant differences between the amounts of SOD1 messenger RNA observed in patients with sporadic disease, patients with familial disease, and normal control subjects. However, many of the atrophic motoneurons from patients with sporadic or familial disease had significantly lower levels of SOD1 messenger RNA, compared to morphologically intact motoneurons. Moreover, motoneurons in the normal spinal ventral horn and precentral motor cortex exhibited significantly higher levels of SOD1 messenger RNA than did other neurons. Our study indicated that vulnerable neurons in amyotrophic lateral sclerosis exhibit high levels of SOD1 messenger RNA, suggesting a close relationship between the SOD1 gene and the pathogenesis of amyotrophic lateral sclerosis.

Aged↗
PubMed1997

Regional and cellular expression of the dentatorubral-pallidoluysian atrophy gene in brains of normal and affected individuals.

Dentatorubral-pallidoluysian atrophy is an autosomal dominant neurodegenerative disorder characterized by dementia and spinocerebellar degeneration. Recently, part of the gene responsible for this disorder was cloned containing a CAG repeat, and predominant neuronal expression of the gene was proved only through Northern blot analysis in rats. In this study, we investigated the regional and cellular expression of the dentatorubral-pallidoluysian atrophy gene in the central nervous system of normal and affected humans, as well as in rat brains. In normal control human subjects, the gene messenger RNA was present in all brain regions examined, with the highest levels seen in the cerebellum, hippocampus, substantia nigra, and pontine nuclei. Its expression in the striatum, globus pallidus, and cerebral cortex was intermediate. The gene was expressed predominantly in neurons; a low but significant level of expression was also seen in glial cells. Neurons susceptible to degeneration in dentatorubral-pallidoluysian atrophy did not selectively express high or low levels of its gene messenger RNA. In brains affected by the disorder, the distribution and levels of gene messenger RNA were comparable to those of the normal controls in all the areas. In the rat brains, gene messenger RNA expression was very similar to that in human brain. It was also expressed predominantly in neurons, while low-level expression was observed in glial cells. It is apparent from these results that the presence of expanded trinucleotide repeats in dentatorubral-pallidoluysian atrophy does not result in the absence of its gene messenger RNA expression or in altered patterns or levels of expression.

Adult↗
PubMed1997

HDR and MDR intracavitary treatment for carcinoma of the uterine cervix. A prospective randomized study.

AIM: Treatment of carcinoma of the uterine cervix by remote afterloading brachytherapy has been accompanied with new isotopes having dose rates different from the classical low-dose rate (LDR) radium source. The dose rate conversion factor from LDR to high-dose rate (HDR) found to be around 0.54 in most studies. As regards medium-dose rate (MDR) brachytherapy, the published data are very few and the experience is still short. In this study the experience of Osaka University Hospital with micro-HDR-Selectron and Selectron-MDR, as a preliminary report of the clinical trial, is presented. PATIENTS AND METHOD: From August 1991 through April 1993, a total of 45 patients with carcinoma of the uterine cervix were randomly allocated to either microSelectron-HDR or Selectron-MDR at the Osaka University Hospital. As regards HDR, dose to point A was adjusted to 32 Gy (for stages I and II). 30 Gy/4 fractions, and 22.5 Gy/3 fractions, for stages III, and IV, respectively. The corresponding values in case of MDR were 35.6, 34 Gy/4 fractions, and 25.5 Gy/3 fractions. External irradiation, according to the stage, was the same in the 2 groups. Nucletron Planning System (NPS) was used for pre-treatment dose calculation at point A, rectal and bladder wall. The dose rate at point A ranged from 24 to 75.6 cGy/min for the HDR group, while for the MDR group ranged among 174.8 to 229.6 cGy/h. RESULTS: The 3-year survival and loco-regional control rates for both modalities were nearly equivalent (62% and 67% for HDR and 68% and 74% for MDR). The cumulative rectal and bladder complication rates were the same in both groups (29% at 3 years), with only 1 patient (MDR-group) developed grade 3 rectal and bladder complication. In this study, point A dose rate correction factor from LDR to HDR was 0.53 and 0.6 from LDR to MDR. CONCLUSIONS: From the previous reports from Osaka University Medical School, as well as others, HDR was proposed as an alternative to LDR brachytherapy for treatment of carcinoma of the uterine cervix. In this report, Selectron-MDR was nearly equivalent to the microSelectron-HDR as regards survival and loco-regional control rates as well as radiation-induced complication. This is a preliminary report, and the study still needs larger number of patients, and longer follow-up period.

Brachytherapy↗
PubMed1997

Acute suppurative perithyroiditis: MR findings.

We report the MR findings in two cases of acute suppurative perithyroiditis. MR has the advantages over other imaging modalities of being able to distinguish areas of inflammation from adjacent normal tissue and of allowing imaging in planes which more accurately demonstrate the extent of the lesion. MR imaging is one of the most useful methods to evaluate this entity.

Acute Disease↗
PubMed1997

Superoxide dismutase-like immunoreactivity in spheroids in Hallervorden-Spatz disease.

Iron accumulation in the basal ganglia and spheroid formation are pathological hallmarks of Hallervorden-Spatz disease (HS). Since an overaccumulation of iron (iron thesaurosis) that exceeds the binding capacity of ferritin could cause oxidative damage, we studied the possible role of oxidative stress in the pathogenesis of HS. The basal ganglia and spinal cord from patients with HS were investigated at autopsy, using histochemistry for iron and immunohistochemistry for Cu/Zn superoxide dismutase (SOD1), Mn superoxide dismutase (SOD2) and ferritin. SOD1-like immunoreactivity (IR), SOD2-IR and ferritin-IR occurred frequently in spheroids observed in the basal ganglia, and associated iron accumulation indicated the possible existence of increased oxidative stress in HS patients. Spheroids in the spinal cord showed intense SOD1-IR and SOD2-IR in HS, in sharp contrast with the occasional weak SOD1-IR and SOD2-IR observed in spheroids from patients with amyotrophic lateral sclerosis (ALS). Neither increased ferritin-IR nor iron accumulation were observed in spinal spheroids from HS and ALS patients. These data may suggest that, at least in the spinal cord, SOD1-IR and SOD2-IR in spheroids in HS patients do not result from oxidative stress directly related to iron accumulation.

Adult↗
PubMed1997

Colour Doppler sonography of breast masses: a multiparameter analysis.

OBJECTIVE: To evaluate signals from breast lesions on both colour and spectral Doppler US, and to correlate findings with angiographic and histopathological features including microvessel density. MATERIALS AND METHODS: One hundred and sixteen breast lesions in 113 patients were evaluated with colour Doppler ultrasonography. Subjective and semi-quantitative assessment of colour signals as well as spectral Doppler analysis were performed and compared. Comparison of colour Doppler features with angiographic and histopathological findings were also carried out. RESULTS: Subjective evaluation revealed that colour signals were more commonly found in malignant (89%) than benign (56%) lesions. Malignant lesions demonstrated a more elaborate vascular network (51%) compared to 12.5% in benign lesions. Spectral Doppler analysis revealed slightly higher specificity values for the pulsatility and resistivity indices, respectively, but lower sensitivity and accuracy values compared to qualitative assessment. Colour Doppler patterns corresponded well with angiograhic images, however, the correlation between colour Doppler parameters and microvessel density was not significant. CONCLUSION: Despite the increased examination time required, spectral analysis does not appear to contribute significantly to the differentiation between malignant and benign breast tumours. Features such as the density, pattern and predominant site of colour signals may be more useful for the evaluation of breast lesions on colour Doppler imaging.

Adolescent↗
PubMed1997

Serotyping of Streptococcus pyogenes isolated from common and severe invasive infections in Japan, 1990-5: implication of the T3 serotype strain-expansion in TSLS. The Working Group for Group A Streptococci in Japan.

To clarify the relationship between the epidemics of severe invasive group A streptococcal infections (streptococcal Toxic Shock-Like Syndrome: TSLS) and common group A streptococcal infections in Japan, we examined the T serotypes of S. pyogenes strains (group A streptococci) isolated from clinical specimens of the streptococcal infections (17999 cases) in the period 1990-5, including the severe infections (TSLS) (29 cases) in the period 1992-5. Characteristic points of the analyses were: (1) dominant serotypes of the infections in these periods were T12, T4, T1, T28 and TB3264, which were consistently isolated; (2) isolates of T3 rapidly increased through 1990 to 1994 while T6 decreased in the period 1990-3; (3) when Japanese area was divided into three parts, T3 serotype tended to spread out from the north-eastern to the south-western area; (4) strains of T3 and T1 serotypes were dominant in the TSLS. Dominant-serotype strains of streptococcal infections did not always induce severe infections and dominance of T3 serotype in the TSLS seemed to be correlated with the increase of T3 in streptococcal infections. These results may indicate that certain clones of S. pyogenes are involved in the pathogenesis of the TSLS.

Adolescent↗