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Masami Tanaka

Publications and source records attributed to Masami Tanaka.

At least 19 recordsLinked to original sources
PubMed2006

Soluble-insoluble-soluble transitions of aqueous poly(N-vinylacetamide-co-acrylic acid) solutions.

Several poly(N-vinylacetamide-co-acrylic acid)s with various copolymer compositions have been synthesized, and their unique phase-transition behavior in aqueous salt (Na2SO4 or NaCl) solutions was investigated. Copolymers containing more than 51 mol % N-vinylacetamide (NVA) show reentrant soluble-insoluble-soluble transitions with increasing temperature. The soluble-insoluble transition temperature (T(p1)) increased linearly with increasing NVA content, whereas the insoluble-soluble transition temperature (T(p2)) was almost constant irrespective of the NVA content. Potentiometric titration of the copolymer solutions suggested that the acrylic acid (AA) carboxyl groups form hydrogen bonds with the NVA amide groups even under soluble conditions. Dehydration of the NVA amides and their consequent hydrogen bonding with the AA carboxyl groups during the soluble-insoluble transition process was indicated by FTIR measurements. Addition of salt (Na2SO4 or NaCl) to the aqueous media reduces the solvent quality and enhances the intra- and interchain interactions of the copolymers. Thus, T(p1) was observed to decrease and T(p2) was observed to increase with increasing salt concentration. However, the addition of urea to the media reverses the concentration dependence of T(p1) and T(p2) by disturbing the intra- and interchain interactions of the copolymers.

Journal Article↗
PubMed2006

Identification and expression profiling of 10 novel spermatid expressed CYPT genes.

To identify candidate genes for poor sperm morphology, we have screened for genes expressed during spermiogenesis. We identified 10 new members of the cysteine-rich perinuclear theca (CYPT) family showing that this family contains at least 15 members, which also includes the casein kinase II target genes. Based on similarity the CYPT sequences could be divided into two groups, Cypt1-10 and the novel members Cypt12-15. The 5'-end of the CYPT family is highly similar to exon1A and part of the first intron of Zfy2. Seven CYPT genes mapped to the X chromosome; six contained an intron and one was intron-less. One CYPT gene mapped to chromosome 3 and one mapped to chromosome 9 which were both intron-less. The upstream region of the CYPT family and Zfy2 genes is conserved. For some the conservation extended over a large region, however, only about 150 nucleotides is conserved among all CYPT members and Zfy2. Nevertheless, the short conserved promoter leads to essentially identical expression profiles for the CYPT family members and Zfy2, which was clearly different from the profile of Zfy1. Expression of the CYPT family and Zfy2 preceded the expression of other spermatid-specific genes such as the transition proteins and the protamines. In situ hybridization revealed a low expression in pachytene spermatocytes from stages IX-X followed by a strong upregulation in spermatids from stage VI with maximum expression in spermatids in stages VII-VIII. The CYPT family may function in the remodeling of the spermatid nucleus before condensation of the DNA.

Animals↗
PubMed2006

[Two cases of classical polyarteritis nodosa associated with MPO-ANCA].

Case 1: An 82 year-old female had a drop-foot, livedo reticularis and paresthesia. MPO-ANCA was positive. Because of developing renal dysfunction, she underwent steroid pulse therapy and dialysis, but died from the complication of congestive heart failure. Autopsy revealed necrotizing arteritis in the interlobular arteries and the arcuate arteries of the kidneys. Crescent formation was not found in the glomeruli. Case 2: A 49-year-old male had a drop foot and numbness. MPO-ANCA was positive. Because of developing renal failure, he underwent dialysis and steroid pulse therapy. MPO-ANCA became negative. Nevertheless, he developed perforation of multiple ulcers in the small intestine and died. Pathohistology revealed arteritis in medium-size arteries at the branch level of the mesenteric arteries. Since the presented two cases showed rapidly and irreversibly aggravated renal function with positive MPO-ANCA, MPA was suspected. However, pathological findings from the autopsy and operation and not the kidney biopsy supported the diagnosis of polyarteritis nodosa (PN). Vasculitis in the arterioles was absent. MPO-ANCA is not specific, and it can be detected in not only MPA, but also PN. The clinical course and pathological findings must be considered to differentiate PN from MPA.

Aged, 80 and over↗
PubMed2005

Effects of bisphenol A given neonatally on reproductive functions of male rats.

Male Sprague-Dawley rats (Crj:CD (IGS) were treated neonatally with bisphenol A (BPA) to evaluate effects on reproductive parameters. Animals were given BPA subcutaneously in corn oil to dosages of 0.002-97 mg/kg body weight, or 0.9 mg/kg 17beta-estradiol (E2) once a day from postnatal day (PND) 0 to PND 9. Preputial separation, copulatory rate, fertility rate, sperm analysis, serum testosterone levels, and gene expression in the testis were assessed. Males in the E2 group showed a decrease in testis weight and alterations of estrogen-mediated gene expression in the testis on PND 10, and by PND 150 incomplete preputial separation, decreases in the copulatory rate, testicular and accessory organ weights and number of sperm. In contrast, males in all BPA groups showed normal reproductive parameters. These results indicate that in male rats, BPA given during the neonatal period neither affected reproductive function nor evoked estrogen-mediated gene responses in the testis.

Animals↗
PubMed2005

Acute physical stress elevates mouse period1 mRNA expression in mouse peripheral tissues via a glucocorticoid-responsive element.

In mammals, the circadian and stress systems (both centers of which are located in the hypothalamus) are involved in adaptation to predictable and unpredictable environmental stimuli, respectively. Although the interaction and relationship between these two systems are intriguing and have been studied in different ways since the "pre-clock gene" era, the molecular interaction between them remains largely unknown. Here, we show by systematic molecular biological analysis that acute physical stress elevated only Period1 (Per1) mRNA expression in mouse peripheral organs. Although behavioral rhythms in vivo and peripheral molecular clocks are rather stable against acute restraint stress, the results of a series of promoter analyses, including chromatin immunoprecipitation assays, indicate that a glucocorticoid-responsive element in the Per1 promoter is indispensable for induction of this mRNA both in vitro and in vivo. These results suggest that Per1 can be a potential stress marker and that a third pathway of Per1 transcriptional control may exist in addition to the clock-regulated CLOCK-BMAL1/E-box and light-responsive cAMP-responsive element-binding protein/cAMP-responsive element pathways.

Acute Disease↗
PubMed2005

Pregnane-type steroids from the inedible mushroom Thelephora terrestris.

Chromatographic fractionation of the methanol extract of fruiting bodies of the inedible Japanese mushroom Thelephora terrestris (Thelephoraceae) has led to the isolation and characterization of two unusual new pregnane-type steroids, 2beta,3alpha-dihydroxypregna-4,7,16-trien-12,20-dione (2) and 1alpha,2beta,3alpha-trihydroxypregna-4,7,16-trien-12,20-dione (3) named terresterones A and B (2, 3), as well as the previously known compound stizophyllin, now assigned as 2beta,3alpha,12beta-trihydroxypregna-4,7,16-trien-20-one (1). Elucidation of their structures and the revision of the stereochemical assignment of stizophyllin were achieved by means of extensive 1D and 2D NMR, UV, CD, IR, MS and molecular modeling experiments. This paper presents the first report on the isolation of true pregnane-type steroids from the Fungi kingdom.

Basidiomycota↗
PubMed2004

Analysis of cell-type-specific gene expression during mouse spermatogenesis.

In rodents, changes in gene expression during spermatogenesis can be monitored by sampling testis from each day during postnatal development. However, changes in gene expression at the tissue level can reflect changes in the concentration of an mRNA in a specific cell type, changes in volume of specific cells, or changes in the cell-type composition. This reflects the cellularity of the tissue. Here we have combined techniques that assess the expression profiles of genes at the whole-tissue level, differential display and DNA array, and, at the level of cellularity, in situ hybridization. Combining results from these techniques allows determination of the cell-type-specific gene-expression patterns of many genes during spermatogenesis. Differential display was used to determine expression profiles with high sensitivity and independent of prior knowledge of the sequence, whereas DNA arrays quickly assess the expression profiles of all the genes. This identified three groups of gene-expression profiles. The major group corresponds to genes that are upregulated in spermatocytes during either the mid- or late- pachytene phase of spermatogenesis (stages VII-XI). This pachytene cluster was gradually extinguished in the later spermatid stages but was followed by another cluster of genes expressed in spermatids. Finally, a group of genes was downregulated during spermatogenesis and probably expressed in nongerm cells. We believe that expression of most genes can be described by a combination of these cell-type-specific expression patterns.

Animals↗
PubMed2004

Effects of antineuronal antibodies from patients with paraneoplastic neurological syndrome on primary-cultured neurons.

Some patients with paraneoplastic neurological syndrome (PNS) produce autoantibodies against tumor and neuronal tissues of symptom-relevant areas. These characteristic antibodies are detected at early stages of the neurological disorder and are reliable markers for the diagnosis of PNS and underlying cancers. These antibodies are thought to be related directly to neuronal damage. However, the passive transfer of antibodies to rodents has been succeeded only in those in which the target antigens were expressed on the cell surface, like Lambert-Eaton myasthenic syndrome. The serum IgGs from patients with PNS and anti-Yo or anti-Hu antibody were not shown to induce the disease by passive transfer or active immunization with these antigen proteins to date. Instead, cytotoxic T lymphocytes (CTLs) against these antigen peptides-presenting targets could be induced in the peripheral blood of PNS patients. However, there is no direct proof of CTLs killing neurons. In this study, we examined the effects of the anti-Yo or anti-Hu antibody on mouse-brain-derived neurons in a primary culture system and found that these antibodies did not kill neurons, but induced the expression of cell adhesion molecules and accelerated neuronal differentiation. These effects of serum IgG fractions containing the anti-Yo or the anti-Hu antibody on the cultured neurons were the same, suggesting that their effects were not through the binding of the antibody to specific antigens, but to some other factors contained in IgG fractions.

Animals↗
PubMed2004

Severe hyperreninemic hypertension associated with spontaneous renal cholesterol crystal embolization.

A 70-year-old man was admitted because of severe hypertension and renal insufficiency. Marked elevation in plasma renin activity (PRA; 34.2 ng/ml per h) was noted. Five days later, the patient developed hemorrhagic duodenal ulcers and panperitonitis, went into shock, and died. An autopsy revealed severe atherosclerosis with marked ulceration in the abdominal aorta. Renal histology showed multiple cholesterol crystal embolization (CCE) associated with infarction. Cholesterol crystals were also detected in the vessels of the gastrointestinal system, including the liver, stomach, colon, and pancreas. Although not common, spontaneous CCE should be considered in elderly patients who present with abrupt onset of severe hypertension associated with renal insufficiency. The most important finding in this patient was severe hyperreninemia. Although potentiation of the renin-angiotensin-aldosterone system is the suggested mechanism for the hypertension in renal CCE, we could not find any reported case of renal CCE with hyperreninemia. It is reasonable to consider that severe hyperreninemia might be overlooked in renal CCE. PRA should be measured in patients with renal CCE, because it may give important information for selecting antihypertensive agents and improving the prognosis. To clarify this possibility, an accumulation of similar cases is necessary.

Acute Kidney Injury↗
PubMed2004

Cyclic azaphilones daldinins E and F from the ascomycete fungus Hypoxylon fuscum (Xylariaceae).

Phytochemical examination of the methanolic extract of fruit bodies of the Xylariaceous ascomycete fungus Hypoxylon fuscum led to the isolation of two azaphilone derivatives named daldinins E and F together with two known compounds daldinin C and 4,5,4',5'-tetrahydroxy-1:1'-binaphthyl using a combination of reversed phase HPLC and high performance gel permeation chromatography. Their structures were determined by 2D NMR, MS, IR, UV, and CD spectroscopy. Their antioxidative activities were also estimated by an indication of a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging effect. The chemosystematics of Hypoxylon is discussed.

Ascomycota↗
PubMed2004

Thelephantins I-N; p-terphenyl derivatives from the inedible mushroom Hydnellum caeruleum.

Phytochemical investigation of the methanolic extract of the fruiting bodies of the inedible mushroom Hydnellum caeruleum resulted in the isolation of six p-terphenyl derivatives named thelephantins I-N (1-6), together with a known compound, dihydroaurantiacin dibenzoate (7). These structures were determined by high-resolution MS, 2D NMR, IR and UV spectroscopic analysis, and by the chemical reactions.

Basidiomycota↗
PubMed2004

Tyromycic acids B-E, new lanostane triterpenoids from the mushroom Tyromyces fissilis.

Four new triterpenoids, tyromycic acids B-E (1-4), were isolated from a methanol-soluble extract of the fruit bodies of the Japanese inedible mushroom Tyromyces fissilis. Tyromycic acids B-D possess a lanostane skeleton, while tyromycic acid E is based on a rare 14(13-->12)abeo-lanostane skeleton. Their structures were determined by spectral data analysis and by single-crystal X-ray crystallography.

Agaricales↗
PubMed2004

Expression of CYP3A4 mRNA is correlated with CYP3A4 protein level and metabolic activity in human liver.

A relatively large amount of human liver tissue was required to determine the exact activity of human hepatic CYP3A. Although, the quantity of available human liver tissue samples is limited. We measured levels of CYP3A4 mRNA by RT-PCR with a radiolabeled primer specific for CYP3A4 and compared mRNA expression with CYP3A4 protein level and metabolic activity in liver. The level of CYP3A4 mRNA was correlated with the levels of CYP3A4 protein and activity. Our results suggest that CYP3A4 protein and activity levels can be predicted from CYP3A4 mRNA levels determined by RT-PCR and using a very small amount of liver tissue.

Blotting, Western↗
PubMed2004

Alcoholic ketoacidosis associated with multiple complications: report of 3 cases.

We report 3 patients with alcoholic ketoacidosis (AKA). All had a history of excessive intake and abrupt termination of alcohol. They showed tachypnea, tachycardia, abdominal tenderness, and epigastralgia. Metabolic acidosis with an increased anion gap, decreased PaCO2 and ketonemia were present. One patient whose ratio of 3-hydroxybutyric acid to acetoacetic acid was 4.0 was associated with diabetic ketoacidosis. All patients were successfully hydrated with electrolyte, glucose and thiamine. Complications such as liver dysfunction, lactic acidosis, acute pancreatitis, Wernicke's encephalopathy, rhabdomyolysis and heart failure were present. Attention should be paid to multiple complications in the treatment of AKA.

Acidosis↗
PubMed2004

[Asialo GM1].

Explore the source record for details and available documents.

Alzheimer Disease↗
PubMed2004

[Two autopsy cases of ANCA-associated glomerulonephritis manifested after contrast medium use].

[Case 1]: An 81-year old man was referred to our hospital with dyspnea and bloody sputum. Computed tomography with contrast medium for the evaluation of metastasis of urinary bladder carcinoma had been performed 4 months previously. On admission, his serum creatinine and potassium were 15.3 mg/dl and 6.9 mEq/l, respectively. His chest X ray revealed cardiomegaly, butterfly shadow and interstitial change, indicating congestive heart failure and interstitial pneumonia. His electrocardiogram showed that he was on the brink of cardiac arrest due to hyperkalemia. Mechanical ventilation and hemodialysis were initiated. Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) was highly positive(321 EU), leading to the diagnosis of MPO-ANCA-associated rapidly progressive glomerulonephritis (RPGN) with interstitial pneumonia. Treatment with pulse methylprednisolone was not effective and he died. Autopsy findings showed crescentic glomerulonephritis, alveolar hemorrhage and interstitial pneumonia with honeycomb formation. [Case 2]: A 73-year old man was referred to our hospital with rapid deterioration of his renal function. He had received a cardiac catheter examination 3 weeks previously. On admission, his serum creatinine was 4.5 mg/dl. His chest X ray showed cardiomegaly and interstitial change. Renal biopsy findings showed crescentic formation in the glomeruli. Moreover, MPO-ANCA was 494 EU, leading to the diagnosis of MPO-ANCA-associated RPGN with interstitial pneumonia. Treatment with pulse methylprednisolone and cyclophosphamide was not effective and he died. Autopsy findings revealed crescentic glomerulonephritis and interstitial pneumonia with honeycomb formation. Here we described two cases of ANCA-associated RPGN complicated by microscopic polyantitis and interstitial pneumonia after the use of contrast medium. The relation between ANCA-associated RPGN and the contrast medium was unclear. However, in the case of rapid deterioration of renal function, MPO-ANCA should be measured even after the use of contrast medium. The complication of lung diseases, especially interstitial pneumonia, should be investigated simultaneously.

Aged↗
PubMed2003

Primary lateral sclerosis: a rare upper-motor-predominant form of amyotrophic lateral sclerosis often accompanied by frontotemporal lobar degeneration with ubiquitinated neuronal inclusions? Report of an autopsy case and a review of the literature.

We report the autopsy findings of an 82-year-old woman who exhibited slowly progressive upper motor neuron signs (pseudobulbar palsy, muscle weakness and positive Babinski's sign) in the absence of lower motor neuron signs, which were followed by progressive dementia and frontotemporal atrophy, and who died 7 years and 4 months after onset of the disease. In this patient, the upper motor neuron system, including the precentral cortex and descending pyramidal tract, was severely degenerated, but the lower motor neurons and innervated skeletal muscles were well preserved. A few lower motor neurons were found to contain cytoplasmic inclusion bodies characteristic of amyotrophic lateral sclerosis (i.e., Bunina bodies and ubiquitin-positive skeins). However, fragmentation of the Golgi apparatus was not evident in the anterior horn cells examined. Therefore, it was considered that the lower motor neurons were also involved, but that the rate of degeneration of these neurons was very slow in the disease process. Marked frontotemporal lobar degeneration characterized by microvacuolation, and ubiquitin-positive neuronal inclusions and dystrophic neurites in cortical layer II were also observed, the precentral cortex being the most severely affected area. Similar ubiquitin-positive structures were also observed in the neostriatum. Finally, a survey of the literature based on this patient's clinical and pathological features led us to conclude that the rare clinical syndrome of primary lateral sclerosis is, in general, a rare upper-motor-predominant form of amyotrophic lateral sclerosis that is often accompanied by frontotemporal lobar degeneration with ubiquitinated neuronal inclusions.

Aged↗