Search PubMed⌕ Search

Biomedical subjects

M Yamada

Publications and source records attributed to M Yamada.

At least 271 records · Page 15Linked to original sources
PubMed2001

[Neuro-Behcet disease mimicking a thalamic tumor].

A case of neuro-Behcet disease presenting as a thalamo-lenticular expanding lesion is reported. A 41-year-old female was admitted with mental deterioration and right hemiparesis. She had been suffering from recurrent oral and genital ulcers and erythema nodosum for several years before admission. Neurological examination on admission revealed poor mental activity, dysarthria and right hemiparesis. Lumbar puncture showed CSF pleocytosis. CT and MRI revealed a thalamo-lenticular expanding lesion. CT showed a homogeneous hypodense lesion of the left lenticulothalamic region, which was enhanced in the central part, exerting a mild mass effect. MRI also revealed the lesion better. The T2 weighted images showed a high intensity signal in the left thalamo-lenticular region and the left peduncle. The T1 weighted images showed a low signal in the corresponding areas with a central enhancement with Gd-DTPA. EEG, SPECT and angiography indicated normal findings. Histologic study of the brain biopsy tissue ruled out a tumor but did not show any specific diagnosis. The patient improved with steroid therapy. In conclusion, the clinical and radiological presentation of neuro-Behcet disease can mimic a cerebral tumor. In such cases, stereotactic biopsy is useful to exclude suspicion of a cerebral tumor.

Adult↗
PubMed2001

[Bilateral chylothorax as initial manifestation of gastric cancer].

We describe a case in which bilateral chylothorax was the initial presenting manifestation of a gastric cancer (scirrhous type). A 58-year-old woman was admitted because of acute right subclavian vein thrombosis. Following admission, she complained of dyspnea on effort and on the 14th hospital day chest X-ray examination revealed bilateral pleural effusion. Biochemical tests of the pleural fluid detected chyle, and cytological examinations revealed mucinous adenocarcinoma bilaterally. An upper gastrointestinal examination revealed gastric cancer (scirrhous type). Carcinoma of the stomach has very rarely been described as the cause of chylothorax, but our findings indicate the need to rule out a gastric neoplasm in patients with chylothorax of no clear cause.

Adenocarcinoma, Scirrhous↗
PubMed2001

Widespread distribution of adenovirus-transduced monkey amniotic epithelial cells after local intracerebral injection: implication for cell-mediated therapy for lysosome storage disorders.

Cell-mediated therapy for mucopolysaccharidosis type VII (MPSVII) was studied using monkey amniotic epithelial cells (mAEC). The cells were transduced with a recombinant adenovirus expressing human beta-glucuronidase (GUSB), and cells overexpressing GUSB were generated. The cells expressed 2000-fold higher activities than the endogenous GUSB activities of nontransduced mAEC, demonstrating that mAEC were successfully transduced with adenoviral vectors. These cells also secreted high levels of GUSB. To clarify the cross-correction of GUSB secreted from mAEC, the conditioned medium containing high levels of GUSB was added into the medium for culturing human or murine fibroblasts established from an MPSVII patient or a mouse model of the disease. Dramatic increases in GUSB activities were observed in both fibroblasts. We then transplanted the cells transduced with an adenovirus expressing LacZ into the caudate-putamen of monkey brain. Survival and distribution of the transplanted cells 1 month after the treatment were evaluated. Histochemical analysis showed that LacZ-positive cells were widely distributed in the brain, suggesting that the transplanted cells had migrated and were distributed even at regions far from the implantation site. These findings suggest that local intracerebral engraftment of genetically engineered amniotic epithelial cells is favorable for the treatment of lysosome storage disorders, whose pathological abnormalities are not restricted to specific regions of the brain.

Adenoviridae↗
PubMed2001

New thiocholine ester substrates for the assay of human serum cholinesterase.

BACKGROUND: Several thiocholine alkanoyl esters were newly synthesized and explored as substrates for the assay of human serum cholinesterase after being subjected to the Ellman reaction (Arch Biochem Biophys 1958;74:443-50 and Arch Biochem Biophys 1959;82:70-7). METHODS: We synthesized thiocholine ester iodides by the method of Renshow et al. (J Am Chem Soc 1938;60:1765-70). We examined solubility in H(2)O, substrate specificity serum for cholinesterase, (spontaneous) self-hydrolysis, storage stability, and reaction conditions for measurement of the activity of the enzyme. RESULTS: Isobutyryl and cyclohexane-carboxyl esters showed the best efficiency for the specific and stable assay of human serum cholinesterase. Aqueous solubility of each was >10 mmol/L, and the reactivity with acetylcholinesterase was negligible. For isobutyryl and cyclohexane-carboxyl esters, respectively, spontaneous hydrolysis in the aqueous phase was approximately 1/25 and approximately 1/175 slower than the enzymatic hydrolysis, and assays with these substrates were linear to 1800 and 3000 U/L, respectively. The K(m) values of these acylthiocholines with human cholinesterase were almost equivalent (6.9 x 10(-3) mmol/L). The substrates were stable in aqueous solution and in the solid state as the iodides for at least 5 years at 5 degrees C. CONCLUSIONS: The isobutyrate and cyclohexane-carboxylate of thiocholine are suitable for the specific assay of human serum cholinesterase.

Cholinesterases↗
PubMed2001

[Autosomal dominant inherited corneal dystrophies associated with TGFBI mutation].

BACKGROUND: Mutations of the transforming growth factor beta-induced (TGFBI) gene whose product is called keratoepithelin (KE) have been identified in 4 major autosomal dominantly inherited corneal dystrophies. The purpose of this study was to identify the mutations in Japanese patients with these dystrophies, and to investigate the nature of corneal deposits. METHOD: Mutations of the TGFBI gene were screened by polymerase chain reaction (PCR) followed by direct sequencing of the PCR products in Japanese patients clinically diagnosed as having granular corneal dystrophy, Avellino corneal dystrophy, lattice corneal dystrophy, and Reis-Bücklers' dystrophy. Corneal specimens obtained from corneal transplants were analyzed by histochemistry (Masson trichrome and Congo red stains), immunohistochemistry, and western blotting using anti KE antibody. I reviewed papers about TGFBI gene mutations previously published. RESULTS: The genotype/phenotype relationship of corneal dystrophies associated with mutations of the TGFBI gene is markedly evident. Avellino corneal dystrophy associated with the R 124 H mutation was the most common form of corneal stromal dystrophy in Japan. In Japan this dystrophy has been called granular corneal dystrophy up to now. Thiel-Behnke dystrophy (R 555 Q) has been also misdiagnosed as Reis-Bücklers' dystrophy. The original Reis-Bücklers' dystrophy is associated with R 124 L, which is compatible with superficial granular corneal dystrophy. Corneal deposits were associated with TGFBI products whose sizes were specific for their mutations. CONCLUSIONS: Mutations of the gene resulted in different types of KE aggregation accompanied with characteristic changes of processing and metabolism. The classification of these diseases according to genetic pathogenesis may be more appropriate than the use of clinical or histological findings.

Corneal Dystrophies, Hereditary↗
PubMed2001

[Epilepsy].

Explore the source record for details and available documents.

Adolescent↗
PubMed2001

Long-term duration of reduced serum complement level following burn injury.

We report the case of a boy whose serum CH50 was below the detection limit following burn injury and skin transplantation. The APCH50 level was slightly decreased, although C3, C4, and the other complements were within the normal range. Cold activation was not detected in his plasma. His peripheral blood monocyte ratio slightly elevated to 19% and then decreased to 5.9%. In this case, burn injury caused the depletion of the complement, particularly in the alternative pathway, and resulted in the reduced CH50 level, although C3 did not show the typical pattern of alternative pathway depletion. In previously reported cases of burn injury, the CH50 level returned to the normal range within 2 weeks. In this patient the reduced level of CH50 continued for 4 months. We should consider burn injury one of the causes of complement deficiency even in cases with a duration of more than 1 month.

Burns↗
PubMed2000

Complete genome structure of the nitrogen-fixing symbiotic bacterium Mesorhizobium loti.

The complete nucleotide sequence of the genome of a symbiotic bacterium Mesorhizobium loti strain MAFF303099 was determined. The genome of M. loti consisted of a single chromosome (7,036,071 bp) and two plasmids, designated as pMLa (351,911 bp) and pMLb (208, 315 bp). The chromosome comprises 6752 potential protein-coding genes, two sets of rRNA genes and 50 tRNA genes representing 47 tRNA species. Fifty-four percent of the potential protein genes showed sequence similarity to genes of known function, 21% to hypothetical genes, and the remaining 25% had no apparent similarity to reported genes. A 611-kb DNA segment, a highly probable candidate of a symbiotic island, was identified, and 30 genes for nitrogen fixation and 24 genes for nodulation were assigned in this region. Codon usage analysis suggested that the symbiotic island as well as the plasmids originated and were transmitted from other genetic systems. The genomes of two plasmids, pMLa and pMLb, contained 320 and 209 potential protein-coding genes, respectively, for a variety of biological functions. These include genes for the ABC-transporter system, phosphate assimilation, two-component system, DNA replication and conjugation, but only one gene for nodulation was identified.

ATP-Binding Cassette Transporters↗
PubMed2000

Sequence and analysis of chromosome 5 of the plant Arabidopsis thaliana.

The genome of the model plant Arabidopsis thaliana has been sequenced by an international collaboration, The Arabidopsis Genome Initiative. Here we report the complete sequence of chromosome 5. This chromosome is 26 megabases long; it is the second largest Arabidopsis chromosome and represents 21% of the sequenced regions of the genome. The sequence of chromosomes 2 and 4 have been reported previously and that of chromosomes 1 and 3, together with an analysis of the complete genome sequence, are reported in this issue. Analysis of the sequence of chromosome 5 yields further insights into centromere structure and the sequence determinants of heterochromatin condensation. The 5,874 genes encoded on chromosome 5 reveal several new functions in plants, and the patterns of gene organization provide insights into the mechanisms and extent of genome evolution in plants.

Animals↗
PubMed2000

Involvement of glycolytic metabolism in developmental inhibition of rat two-cell embryos by phosphate.

To elucidate the mechanism by which phosphate induces developmental inhibition of rat 2-cell embryos, we examined the mutual effects of glucose and other glycolytic and non-glycolytic sugars, the non-metabolizable glucose analogue, and glycolytic inhibitors on the inhibitory effect of phosphate. In the absence of glucose, 30-49% of embryos treated with 10-500 microM phosphate were able to develop to morula and blastocysts. On the other hand, in the presence of 5 mM glucose, 10 microM phosphate decreased the developmental rate of 2-cell embryos to the 4-cell stage and completely inhibited the development beyond the 4-cell stage. In contrast, glucose showed no influence on development in phosphate-free medium. Similarly to glucose, the other glycolytic sugars fructose (5 mM) and mannose (5 mM) enhanced the inhibitory effect of 10 microM phosphate but had no influence in the absence of phosphate. In contrast, the non-glycolytic sugar and non-metabolizable glucose analogue N-acetylglucosamine and 3-O-methylglucose (3-O-MGlc), respectively, did not enhance the effects of phosphate. 2-Deoxyglucose (2DGlc), another glucose analogue that is non-metabolizable but is converted by hexokinase to 2DGlc 6-phosphate, at concentrations as low as 0.1 mM completely inhibited cell cycle progression of 2-cell embryos cultured in glucose-free (Glc(-)) medium with 10 microM phosphate. In contrast, in the absence of phosphate, 2DGlc at the same concentration allowed 55% of 2-cell embryos to develop to morula and blastocyst stages. Addition of an inhibitor of enolase in glycolysis, sodium fluoride (NaF), at 1 mM to the Glc(-) medium also enhanced the inhibitory effects of 10 microM phosphate, whereas 1 mM NaF in the absence of phosphate showed no inhibitory effects on the development of 2-cell embryos to morula and blastocyst stages. From these results, disturbance of glycolysis is a critical reason for the developmental inhibition caused by phosphate in early rat embryos in culture.

Animals↗