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Biomedical subjects

M Osawa

Publications and source records attributed to M Osawa.

At least 181 records · Page 10Linked to original sources
PubMed1996

Fatal methemoglobinemia caused by liniment solutions containing sodium nitrite.

We describe a case of fatal methemoglobinemia (MetHb-emia) resulting from application of liniment solution containing large quantities of sodium nitrite. As a remedial treatment of atopic dermatitis, the liniment solution was applied all over the boy's body. Autopsy findings showed no significant macroscopic or microscopic findings except blood tinted chocolate brown color and chronic atopic dermatitis over the whole surface of the body. Quantitation of the methemoglobin (MetHb) in the blood was performed using spectrophotometer; MetHb concentration of the blood was 76%. Ion chromatographic determination revealed a nitrite concentration of 1 mg/L in the serum. Such a liniment solution is not authorized by the Ministry of Public Welfare.

Administration, Topical↗
PubMed1996

Linkage-disequilibrium mapping narrows the Fukuyama-type congenital muscular dystrophy (FCMD) candidate region to <100 kb.

Fukuyama-type congenital muscular dystrophy (FCMD), the second most common form of muscular dystrophy in Japan, is an autosomal recessive severe muscular dystrophy associated with brain anomalies. After our initial mapping of the FCMD locus to chromosome 9q31-33, we have further defined the locus within a approximately 5-cM region between D9S127 and D9S2111 and have found linkage disequilibrium between FCMD and D9S306 in this candidate region on 9q31. The high prevalence of FCMD among the Japanese, who are a relatively isolated population, provides an opportunity to utilize linkage-disequilibrium mapping. We developed three new microsatellites, near D9S306, from the FCMD YAC contig, determined their positions on YACs, and performed linkage-disequilibrium mapping with these markers and other newly published loci. The maximum value of p(excess), which represents the strength of linkage disequilibrium, was obtained at D9S2107; and this value showed a relatively steady rise and fall across the region that is likely to contain FCMD. Distances between FCMD and each marker were presumed to be approximately 1 Mb, approximately 350 kb, approximately 140 kb, approximately 20 kb, approximately 280 kb, approximately 450 kb, and approximately 740 kb for D9S306, A107XF9, D9S2105, D9S2107, D9S172, D9S299, and D9S2109, respectively. Haplotype analysis using the three closest markers D9S2105, D9S2107, and D9S172 indicated that most FCMD-bearing chromosomes are derived from a single ancestral founder and suggested that these markers can be used for the diagnosis of sporadic FCMD. Thus, the FCMD gene is most likely to lie within a region of <100 kb containing D9S2107.

Alleles↗
PubMed1995

Somatic mosaicism for a DMD gene deletion.

Mosaicism is a mixed state, with two cell populations of different genetic origins caused by a cell mutation occurring after fertilization. In the present case, DNA analysis of lymphocytes led to a DMD diagnosis before death. Postmortem immunocytochemical and DNA analysis showed somatic mosaicism. At age 18 years, blood lymphocyte DNA analysis showed a DMD gene deletion, upstream from exon 7 to the 5' end containing both muscle and brain promoters. As the patient's mother and elder sister had no deletions, he was considered to have a new mutation. Immunocytochemical studies of postmortem tissues showed that dystrophin was absent from the tongue, deltoid, intercostal, psoas and rectus femoris muscles, but there was a mix of dystrophin-positive and negative fibers in the rectus abdominis, cardiac, temporalis and sternocleidomastoid muscles. All diaphragm cells were dystrophin positive. Polymerase chain reaction (PCR) amplification from all tissues except the temporalis and sternocleidomastoid muscles, diaphragm and kidney, in which no deletion was found, showed the deletion from at least exon 6 to the 5' end containing both muscle and brain promoters. In this case, a genomic deletion of the DMD gene contributed to the formation of tissues derived from both ectoderm and endoderm, and cells of mesodermal origin showed genotypic and phenotypic heterogeneity. Our results indicate a mutation of the present case may have occurred just before the period of germ layer formation.

Brain Chemistry↗
PubMed1995

Hematopoietic stem cells found in lineage-positive subsets in the bone marrow of 5-fluorouracil-treated mice.

It is known that treatment of mice with 5-fluorouracil (5-FU, 150 mg/kg) confers radioprotection. To investigate this effect, we performed bone marrow transplantation (BMT) using C57BL/6-Ly5 congenic mice treated with 5-FU five days prior to experiments. The mononuclear cells (MNC) in 5-FU-treated bone marrow (BM) were 10 times more radioprotective than those in untreated BM. Moreover, the number of BM MNC expressing c-kit on their surface from 5-FU-treated mice was markedly decreased relative to those from untreated controls. These results showed that the surface characteristics of cells that contributed to this radio-protective effect differ from those of stem cells as reported recently. BM MNC of mice treated with 5-FU were separated on the basis of expression of the lineage-specific antigens (Lin), c-kit, and Ly6A/E. When injected into lethally irradiated mice, 1,000 Lin+ and Lin-c-kit+Ly6A/E+ cells showed radioprotective effects such that 100% and 60% survived, respectively. Flow cytometric analysis 165 days after BMT showed that 88.8% and 65.1% of peripheral blood (PB) in mice transplanted with Lin+ and Lin-c-kit+Ly6A/E+ was derived from donor mice, respectively. After six months, donor-derived Lin-c-kit+Ly6A/E+ cells which showed radioprotective effects on a secondary irradiated host were detected from mice transplanted with Lin+ cells from 5-FU-treated mice. Taken together, these findings demonstrated that stem cells expressing Lin+ present in the BM of mice treated with 5-FU other than Lin-c-kit+Ly6A/E+ cells and these Lin+ cells play an important role in the recovery of myeloablative mice.

Animals↗
PubMed1995

Developmental defects of lymphoid cells in Jak3 kinase-deficient mice.

Jak3 is a tyrosine kinase mediating cytokine receptor signaling through the association with the common gamma chain of the cytokine receptors such as IL-2, IL-4, IL-7, IL-9, and IL-15. Unlike other members of the Jak family, the expression of Jak3 is highly restricted in hematopoietic cells. To elucidate in vivo function of Jak3, Jak3-deficient mice were generated by homologous recombination. Mice homozygous for Jak3 null mutation showed severe defects, specifically in lymphoid cells. B cell precursors in bone marrow, thymocytes, and both T and B cells in the spleen drastically decreased, although these defects were significantly recovered as aging occurred. Peripheral lymph nodes, NK cells, dendritic epidermal T cells, and intestinal intraepithelial gamma delta T cells were absent. Normal number of hematopoietic stem cells in bone marrow from Jak3-deficient mice and the similar capability to generate myeloid and erythroid colonies as wild-type mice indicated specific defects in lymphoid stem cells. Furthermore, the abnormal architecture of lymphoid organs suggested the involvement of Jak3 in the function of epithelial cells. T cells developed in the mutant mice did not respond to either IL-2, IL-4, or IL-7. These findings establish the crucial role of Jak3 in the development of lymphoid cells.

Animals↗
PubMed1995

Sandwich capture enzyme immunoassay for water soluble blood group B substance in secretor saliva.

Sandwich capture enzyme immunoassays (EIA I and EIA II) are described. Water soluble B substance was reacted simultaneously with affinity-purified dinitrophenyl goat anti-B IgG and affinity-purified goat anti-B IgG-peroxidase conjugate. The complex formed of B substance, dinitrophenyl IgG and IgG-peroxidase conjugate was trapped onto a polystyrene ball coated with affinity-purified goat anti-dinitrophenyl bovine serum albumin IgG. After washing, peroxidase activity bound to the ball was assayed by fluorometry (the sandwich capture EIA I). In the sandwich capture EIA II, the complex was, after thorough washing, eluted from the ball with dinitrophenyl-L-lysine, and then peroxidase activity in the eluate was assayed. The thorough washing and elution processes improved the sensitivity 3.3-fold, and B substance in saliva samples from type B and AB secretors could be detected 200- to 500-fold more sensitively than hemagglutination inhibition, a method commonly used in forensic practices.

ABO Blood-Group System↗
PubMed1995

Newly designed bayonet clips for complicated aneurysms: technical note.

Three newly designed bayonet clips (crankshaft clips) are presented. They were designed to occlude aneurysms with irregular necks by using the angle and shank portion of a bayonet clip (shank clipping). The new clips have shorter distal blades and longer shanks (proximal blades), and the angle portions are bent to an angle of smaller degree. These clips are useful particularly for aneurysms located in a wider space.

Constriction↗
PubMed1995

Regulation of human Gc (vitamin D--binding) protein levels: hormonal and cytokine control of gene expression in vitro.

Studies were performed in Hep3B hepatocytes to better elucidate the mechanisms regulating circulating levels of human group-specific component (Gc). We measured changes in Gc messenger RNA (mRNA) synthesis and levels of secreted protein resulting from treatment of hepatocytes with cytokines and hormones known to influence synthesis of other proteins of hepatic origin. We particularly focused on compounds known to be prototypic stimulants during the acute phase response. Interleukin-6 (IL-6) and dexamethasone were shown to increase Gc mRNA approximately twofold while transforming growth factor beta (TGF beta) decreased Gc mRNA in a dose-dependent fashion by up to fivefold. The effects on secreted Gc protein levels were similar. These results indicate that Gc protein appears to be regulated differently than the other members of this gene family, albumin and alpha-fetoprotein (AFP), which are negative acute phase reactants. In addition, these contrasting effects on Gc synthesis of IL-6 and dexamethasone and of TGF beta suggest that high basal levels of Gc synthesis may be maintained during the acute phase response.

Actins↗
PubMed1995

Influence of antemortem medication on the determination of brain death.

Post-mortem concentration of pentobarbital in the blood and brain of two deceased neurosurgical patients was determined by gas chromatography/mass spectrometry. Patients treated with barbiturate for elevated intracranial pressure after head injury may incur brain death. In the present two cases of brain death a large amount of barbiturate remained in the brain, even when the blood concentration was not detectable, possibly because the blood flow was stagnant in the brain. It is suggested that a patient under barbiturate coma should be given serious consideration as to the determination of brain death, even if barbiturate is negative in the blood.

Adolescent↗
PubMed1995

[A case of cerebral infarction in a young adult following an abuse of cocaine and other drugs].

We reported a case of cerebral infarction in a young adult following an abuse of cocaine and other drugs. A 27-year-old male was admitted to our hospital because of the abrupt onset of right hemiplegia and dysarthria. Brain CT and MRI examinations showed cerebral infarction in the region of the left caudate head and the left corona radiata. Cerebral angiography revealed total occlusion at the origin of the left middle cerebral artery, with neither vascular malformation nor atherosclerotic change. There were no obvious causes that might lead to cerebral infarction in young adults, including potential cardiac sources of embolism, abnormalities of blood coagulation, or collagen vascular diseases. From his history we learned he had started abusing cocaine and other drugs at the age of 16 years, and that he had been addicted to these drugs up to at least 2 months earlier than the onset of cerebral infarction, so we suggested his drug abuse might have affected the occurrence of cerebral infarction. We would like to emphasize that using 'drugs' should be taken into consideration as a possible cause of cerebral infarction in young adults.

Adult↗
PubMed1994

Sperm and its soluble extract cause transient increases in intracellular calcium concentration and in membrane potential of sea urchin zygotes.

Fertilization is known to initiate a transient increase of intracellular calcium concentration and an accompanying change of membrane potential in sea urchin eggs. If the fertilization membrane and hyaline layer are removed, sperm can again enter fertilized eggs (refertilization). We have found that Ca2+ and voltage transients were repeatedly induced in fertilized eggs during refertilization. Similar changes were also obtained by external application of a soluble extract of sperm to fertilized eggs. This sperm extract caused no changes in unfertilized eggs. The active factor in the sperm extract survives heating (100 degrees C, 10 min) and incubation with pronase. Its molecular weight is less than 1300.

Animals↗
PubMed1994

Cytochemical identification of programmed cell death in the fusing fetal mouse palate by specific labelling of DNA fragmentation.

The process of palate fusion was examined in 13- and 14-day-old mouse fetuses by using in situ staining for nuclear DNA fragmentation (TUNEL method) and immunofluorescent staining for keratin, with special reference to the disruption of the midline epithelial seam. TUNEL-positive cells were found in the disappearing midline seam and the oral and nasal epithelial triangles at some late stages of palate fusion, but not in the palatal shelves prior to contact or in the intact midline epithelial seam. It seems that DNA fragmentation or apoptosis is required for the midline epithelial seam to disrupt, but may not be necessary for initial contact of palatal shelves or for the epithelial fusion of opposing palatal shelves. A similar sign of apoptotic cell death was observed in the disappearing epithelial seam between the fusing nasal septum and dorsal palate. We have demonstrated that apoptotic programmed cell death does occur at some stages of palate fusion, although the present results do not exclude the possibility of epithelial-mesenchymal transformation and the oral and nasal migration of midline epithelial cells.

Animals↗
PubMed1994

A newly designed attachment device of multipurpose frame for neuronavigator. Technical note.

A newly designed attachment device of the multipurpose head frame (Sugita) for Neuronavigator (Watanabe) is presented with an illustrative case of glioblastoma in an eloquent area. This has extended the usefulness of the neuronavigator for those who prefer and use the multipurpose head frame, while the requirements for keeping a stereotactic combination and the original concept of the multipurpose head frame, as well as that of the neuronavigator have been kept undisturbed.

Aged↗
PubMed1994

A portable diffuse reflectance spectrophotometer for the rapid and automatic measurement of meat pigments.

A portable reflectance spectrophotometry system, which can measure a wide range of absorbance and has an adhesive pad type fibre optic probe, was developed to improve the availability of non-invasive reflectance spectrophotometry. A Czerny-Turner type spectrometer, which can be connected to an optical fibre probe, was developed, and a linear charge coupled device (CCD) was used as its light detector to increase data acquisition speed. The scanning time of the linear CCD is automatically controlled in accordance with the reflectance of meat to increase the dynamic range of absorption. We tried to apply this instrument to samples of meat pigments in order to demonstrate whether reflectance spectrophotometry is suitable for evaluating the freshness of meat. We examined the myoglobin solution in the form of the met-derivative in order to detect the concentration of myoglobin. The absorbance spectrum of myoglobin in the range of 0-4 mg dl(-1) was successfully distinguished with this instrument.

Animals↗
PubMed1994

Clinical variability of congenital myopathy with type 1 fiber atrophy: a long-term observation of three cases.

The variable clinical courses of three cases of congenital fiber type disproportion (CFTD) over a period of 10 years are presented. All showed improvement in early childhood, but subsequently, varying degrees of deterioration were noted: specifically, marked deterioration in case 2 and decreased muscle strength in case 3. Maximal motor function levels were attained differently among the cases. Histological findings included type 1 fiber hypotrophy and increased internal nuclei in common in all cases. Fine structural changes, such as patchy areas of myofibrillar degeneration, were noted in cases 1 and 2 (second biopsy), and cytoplasmic bodies were seen in case 2 (second biopsy). Myotubes were noted in case 3. The degree of cyto-architectural changes did not correlate with clinical severity. The heterogeneity of CFTD is also discussed.

Adolescent↗