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Biomedical subjects

C Mori

Publications and source records attributed to C Mori.

At least 73 records · Page 4Linked to original sources

Targeted disruption of gp130, a common signal transducer for the interleukin 6 family of cytokines, leads to myocardial and hematological disorders.

gp130 is a ubiquitously expressed signal-transducing receptor component shared by interleukin 6, interleukin 11, leukemia inhibitory factor, oncostatin M, ciliary neurotrophic factor, and cardiotrophin 1. To investigate physiological roles of gp130 and to examine pathological consequences of a lack of gp130, mice deficient for gp130 have been prepared. Embryos homozygous for the gp130 mutation progressively die between 12.5 days postcoitum and term. On 16.5 days postcoitum and later, they show hypoplastic ventricular myocardium without septal and trabecular defect. The subcellular ultrastructures in gp130-/- cardiomyocytes appear normal. The mutant embryos have greatly reduced numbers of pluripotential and committed hematopoietic progenitors in the liver and differentiated lineages such as T cells in the thymus. Some gp130-/- embryos show anemia due to impaired development of erythroid lineage cells. These results indicate that gp130 plays a crucial role in myocardial development and hematopoiesis during embryogenesis.

Animals↗

Testis-specific expression of mRNAs for a unique human type 1 hexokinase lacking the porin-binding domain.

Several enzymes in the glycolytic pathway are reported to have spermatogenic cell-specific isozymes. We reported recently the cloning of cDNAs representing three unique type 1 hexokinase mRNAs (mHk1-sa, mHk1-sb, and mHk1-sc) present only in mouse spermatogenic cells and the patterns of expression of these mRNAs (Mori et al., 1993: Biol Reprod 49:191-203). The mRNAs contain a spermatogenic cell-specific sequence, but lack the sequence for the porin-binding domain that somatic cell hexokinases use to bind to a pore-forming protein in the outer mitochondrial membrane. We now report the cloning of cDNAs representing three unique human type 1 hexokinase mRNAs (hHK1-ta, hHK1-tb, and hHK1-tc) expressed in testis, but not detected by Northern analysis in other human tissues. These mRNAs also contain a testis-specific sequence not present in somatic cell type 1 hexokinase, but lack the sequence for the porin-binding domain. The hHK1-tb and hHK1-tc mRNAs each contain an additional unique sequence. The testis-specific sequence of the human mRNAs is similar to the spermatogenic cell-specific sequence of the mouse mRNAs. Furthermore, Northern analysis of RNA from mouse, hamster, guinea pig, rabbit, ram, human, and rat demonstrated expression of type 1 hexokinase mRNAs lacking the porin-binding domain in the testes of these mammals. These results suggest that hexokinase may have unique structural or functional features in spermatogenic cells and support a model proposed by others for hexokinase gene evolution in mammals.

Amino Acid Sequence↗

[Effect of ethanol on expression of nitric oxide synthases in the cerebral culture cells from chick embryo].

The effect of ethanol on nitric oxide synthase (NOS) activity was examined histochemically and biochemically in cultured cerebral cells of chick embryos. The cells were isolated from 13- to 14-day-old chick embryos to which 10% ethanol (ethanol group) or saline (control) had been injected on the 3rd day of embryogenesis. Expression of NADPH diaphorase in cultured cells was stained using nitro blue tetrazolium (NBT). The activity of NOS was observed by the following 2 assays: NADPH diaphorase activity was determined using the substrate NBT with the cofactor NADPH, and NOS activity was determined by measurement as radiochemical activity of the conversion of [3H]L-arginine to [3H]L-citrulline. The number of isolated cells and viability from one cerebrum of chick embryo were 3 approximately 4 x 10(6) and more than 97%, respectively. In the neuronal cells, moderately positive expression of NADPH diaphorase was first detected on about the 3rd day of culture in both the control and ethanol group. The NADPH diaphorase and NOS activities in the isolated cells were higher in the ethanol group than in the control group. The NADPH diaphorase and NOS activities were significantly higher in the ethanol group than in the control group on the 4th and 2nd day of culture, respectively. These findings suggest that NO-released by elevated NADPH diaphorase activity and NOS activity is responsible for the induction of neuronal cell disorders attributed to chronic ethanol damage.

Animals↗

[Anterior denture teeth selected for complete dentures].

The purpose of this study was to investigate the influence of sex and age on the selection of color, size, and form of anterior teeth for complete dentures. A sample representing one hundred eighty-five edentulous patients whose complete dentures were made with. Real Crown teeth (Shofu Inc.) was obtained. The results were as follows: 1) Lighter teeth were selected for females than males, but age had no relation to the selected color of the teeth. 2) Larger teeth were selected for males than females, but age had no relation to the selected size of the teeth. 3) The combination and tapering forms were selected frequently, the combination form was used more frequently for females than males and the tapering form was used more frequently for males than females.

Adult↗

Placental defect and embryonic lethality in mice lacking hepatocyte growth factor/scatter factor.

Hepatocyte growth factor/scatter factor (HGF/SF) functions as a mitogen, motogen and morphogen for a variety of cultured cells. The genes for HGF/SF and its receptor (the c-met proto-oncogene product) are expressed in many tissues during the embryonic periods and in the adult. HGF/SF is thought to mediate a signal exchange between the mesenchyme and epithelia during mouse development. To examine the physiological role of HGF/SF, we generated mutant mice with a targeted disruption of the HGF/SF gene. Here we report that homozygous mutant embryos have severely impaired placentas with markedly reduced numbers of labyrinthine trophoblast cells, and die before birth. The growth of trophoblast cells was stimulated by HGF/SF in vitro, and the HGF/SF activity was released by allantois in primary culture of normal but not mutant embryos. These findings suggest that HGF/SF is an essential mediator of allantoic mesenchyme-trophoblastic epithelia interaction required for placental organogenesis.

Allantois↗

Tissue accumulation of sulfatide and GM3 ganglioside in a patient with variant Farber disease.

We analyzed the lipids in the tissues of a patient with an atypical form of Farber disease who developed several clinical symptoms not seen in patients with typical Farber disease (acid ceramidase deficiency). Lipids were extracted from formalin-fixed brain, liver and kidney and purified by ion exchange and silica gel column chromatographies and further by high-performance liquid chromatography on a silica gel column. We performed structural and quantitative analyses of three lipids named lipids X, Y and Z. Lipid X accumulated in the liver but not in the brain. Accumulation of lipids Y and Z was observed in liver and kidney. The content of lipid Y in the patients liver was more than ten times that in a control. The structures of lipids X, Y and Z were confirmed by means of 1H-nuclear magnetic resonance spectroscopy, fast atom bombardment mass spectrometry, infrared absorption spectroscopy, and component analysis involving gas liquid chromatography and gas chromatography-mass spectrometry. The structures of lipids X, Y and Z were identified as those of ceramide, sulfatide and GM3 ganglioside, respectively. These results suggest two possibilities. One is that the accumulation of glycolipids such as sulfatide and GM3 ganglioside is a secondary event produced by the accumulation of ceramide due to ceramidase deficiency. The other is that the accumulation of glycolipids other than ceramide is due to a deficiency of sphingolipid activator proteins which may affect the degradation of sulfatide and GM3 ganglioside as well as ceramide.

Acid Ceramidase↗

Programmed cell death in the interdigital tissue of the fetal mouse limb is apoptosis with DNA fragmentation.

BACKGROUND: Programmed cell death is an essential event during mammalian morphogenesis which eliminates unnecessary cells to accomplish histogenesis and organogenesis. Cell death in interdigital spaces of the developing limb is a classical example of morphogenetic cell death. We investigated whether classical programmed cell death in the interdigital tissue of the developing limb in mice is apoptosis with fragmentation of nuclear DNA and also examined sequentially the occurrence of programmed cell death and cell proliferation in the developing limb of mouse fetuses to analyze their interrelation. METHODS: We examined the occurrence of apoptotic cell death in the developing limbs of mouse fetuses by using Nile blue sulphate staining, agarose gel electrophoresis for detecting DNA laddering, and a cytochemical labeling of DNA fragmentation. We also labeled proliferating cells using BrdU/anti-BrdU immunohistochemistry and examined the interrelation between apoptotic programmed cell death and cell proliferation. RESULTS: DNA ladders, a biochemical evidence of apoptosis, were detected in DNA extracts from the interdigital tissue of day 13 mouse fetuses by agarose gel electrophoresis. Programmed cell death and DNA fragmentation were detected by Nile blue staining and cytochemical labeling of DNA fragmentation, respectively, in the interdigital mesoderm and in the regions of presumptive joints of the digit. BrdU/anti-BrdU immunohistochemistry for identifying proliferating S-phase cells revealed that interdigital mesenchymal cells cease DNA synthesis before programmed cell death and DNA fragmentation begin. CONCLUSIONS: We confirmed that both cytological apoptotic alterations and fragmentation of nuclear DNA occur in the interdigital tissue and presumptive joint areas of fetal mouse limbs, and they appear to play a significant role in the separation of digits as well as the formation of joint cavities.

Animals↗

Characterization of Fsc1 cDNA for a mouse sperm fibrous sheath component.

The fibrous sheath is a major cytoskeletal structure in the principal piece of the mammalian sperm flagellum. We have cloned a cDNA and used it to characterize the expression of mRNA for a mouse sperm fibrous sheath protein. Peptides from a tryptic digest of fibrous sheath proteins were separated by HPLC and a 31 amino acid sequence was obtained from one of the peptides. Through the use of degenerate oligonucleotide polymerase chain reaction (PCR) primers predicted from this sequence, an 80-bp product was amplified from mouse testis first-strand cDNA. This was utilized as a probe to isolate a 2.9-kb cDNA clone from a mouse round spermatid cDNA library. Sequence analysis of the cDNA clone showed that it encodes a protein with an open reading frame of 849 amino acids and includes the original peptide sequence. The predicted protein has a molecular weight of 93,795 and contains 32 cysteine residues and 32 potential phosphorylation sites. It has no significant homology with other known cytoskeletal proteins. Northern blot analysis detected an mRNA of approximately 3 kb that was abundant in round spermatids of the mouse and in testes from six other mammalian species, but not in twelve somatic tissues from the mouse. In situ hybridization analysis indicated that the mRNA is first detected in step 1-6 spermatids, is most abundant in step 8-12 spermatids, and decreases in amount in step 13-15 spermatids, suggesting that expression of the mRNA occurs in the postmeiotic phase of spermatogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Disruption of the mouse RBP-J kappa gene results in early embryonic death.

The RBP-J kappa protein is a transcription factor that recognizes the sequence C(T)GTGGGGA. The RBP-J kappa gene is highly conserved in a wide variety of species and the Drosophila homologue has been shown to be identical to Suppressor of Hairless [Su(H)] which plays important roles in the development of the peripheral nervous system. To explore the function of the RBP-J kappa gene in mouse embryogenesis, a mutation was introduced into the functional RBP-J kappa gene in embryonic stem (ES) cells by homologous recombination. Null mutant ES cells survived but null mutant mice showed embryonic lethality before 10.5 days of gestation. The mutant mice showed severe growth retardation as early as 8.5 days of gestation. Developmental abnormalities, including incomplete turning of the body axis, microencephaly, abnormal placental development, anterior neuropore opening and defective somitogenesis, were observed in the mutant mice at 9.5 days of gestation. RBP-J kappa mutant embryos expressed a posterior mesodermal marker FGFR1. Their irregularly shaped somites expressed a somite marker gene Mox 1 but failed to express myogenin. The RBP-J kappa gene was revealed to be essential for postimplantation development of mice.

Animals↗

Synthesis of some 4H-pyrido[1,2-a]pyrimidin-4-ones investigated as antimicrobial agents.

Synthesis of some 4H-pyrido[1,2-a]pyrimidin-4-ones and assay of their antibacterial and antifungal activity are reported. Compounds 3a-e,g were prepared by reaction of substituted 2-chloromethyl-4H-pyrido[1,2-a]pyrimidin-4-ones 2a-c with suitable amines. These compounds and the previously obtained analogues 5a-o and 6a,b have been tested for their antimicrobial activity. All tested compounds were devoid of antimicrobial activity.

Anti-Bacterial Agents↗

Computer-aided clinical laboratory diagnosis in conjunction with the electronic medical textbook.

1. INTRODUCTION. Medical knowledge has been increasing and diversifying on a worldwide scale, while the specialization of physicians has been extended vigorously. Under this environment, it may be natural that mistakes are made in a comprehensive diagnosis, as the physician cannot master all of this dramatically increasing volume of knowledge. The knowledge has extended beyond the memory of human beings, thereby causing the deterioration of service; this is called the "Knowledge crisis." To tackle this problem, the Electronic Medical Textbook (EMT) has been conceived and set up as a medical knowledge base for physicians to optimize both their specialties and activities in clinical practice. Meanwhile, laboratory information systems were widely introduced. However, there are few systems which allow interpretation of the findings obtained. With this in mind, we have improved the utility of the EMT by enhancing its function with laboratory information follow-up, thesaurus back-up, Japanese language support, and online access. 2. SYSTEM DESCRIPTION. The knowledge database for medical decision-making consists of three categories: 1) Medical domain knowledge (including approximately 3500 diseases) from the AMA's "The Current Medical Information & Terminology (CMIT)"; 2) Knowledge on relationship between laboratory testing results and diseases from "The Effects of Disease on Clinical Laboratory," compiled by the AACC; and 3) Clinical testing knowledge from Otsuka's laboratory test handbook "Kensa-Kojien." These categories are connected by links in the process of cross-reference. In actual use, the first is to select the supporting system bringing up clinical signs and findings on CRT from which users can then choose any representations corresponding to the patient's clinical state. Once the relevant objects have been selected, the system presents the correlated investigative tests to be performed, along with a scope of laboratory tests ordering for its initial investigative task. The required tests against the data objects denoted by "High," "Low," or "Abnormal" are linked to possible diagnoses, which appear on CRT in order of likelihood. Similarly, the possible diagnoses can be obtained directly by consulting the patient's laboratory test results in linkage, by way of automated data transformation into the corresponding data object using the reference interval. If necessary, additional information relative to clinical signs can be added. With the repetition of this procedure, clinically useful tests can be located, thus increasing the likelihood of an appropriate diagnosis. The proposed diseases can be confirmed through cross-reference to the patient's clinical signs from the description in the Textbook on CRT. In order to bolster the efficiency of cross-checking on CRT, the sentences including hit-words are highlighted in red. Moreover, with regard to specific keywords for disease, those sentences are highlighted in green to emphasize differences in between. In parallel, the description points out an active behavior of laboratory test results in the progression of the disease and is also able to display applicable laboratory test listings. Furthermore, this knowledge-based interpretation system is directly accessible via online network services in referring to laboratory test results. 3. CONCLUSION. A combination of the CMIT and laboratory diagnostic information in the knowledge database allows the narrowing down of proposed diagnoses due to its flexible approach, which depends not only on clinical signs and findings, but also on applicable test-ordering support and suggestions. This enhances the potential usefulness of the EMT. The system contributes to the support of the diagnostic procedures and assists in educational setting, because the process can be operated in reverse based on clinical signs and laboratory findings in a dialogue style on CRT. The related disease description highlighted in color has won a good reputation dur

Artificial Intelligence↗

Sexing of human embryos and fetuses by fluorescent in situ hybridization (FISH) to paraffin-embedded tissues with sex chromosome-specific DNA probes.

A fluorescent in situ hybridization (FISH) study was carried out on paraffin sections of human embryonic and fetal tissues with two DNA probes, DXZ1 and DYZ1 (Oncor), for X and Y chromosome-specific DNA sequences, respectively. The specificity of the DNA probes was confirmed on metaphase and interphase lymphocytes of healthy normal adult males. The paraffin blocks of the human embryonic and fetal tissues examined in the present study had been stored at room temperature for up to 5 years after fixation in 4% paraformaldehyde. All the seven embryos and five fetuses examined were successfully sexed by FISH. The cells from three embryos and four fetuses were positive for a hybridization signal with each of the DXZ1 and DYZ1 probes and they were classified as male. The cells from the remaining four embryos and one fetus were positive for two identical hybridization signals with the DXZ1 probe in a nucleus instead of the absence of the signal hybridized with DYZ1, indicating that their cells have two X chromosomes but no Y chromosomes. The FISH results for the five fetuses examined were consistent with their genital sex and/or gonadal histology. The FISH results were highly specific and no false positive or false negative results were obtained. Thus, the FISH technique has been shown to visualize specific DNAs in situ on paraffin sections and to be useful to determine the sex of fixed embryos and fetuses retrospectively.

Cells, Cultured↗

Highly sensitive detection of viral RNA genomes in blood specimens by an optimized reverse transcription-polymerase chain reaction.

A protocol was developed for a highly sensitive detection of viral RNA in blood specimens by reverse transcription coupled with a nested polymerase chain reaction. Using Japanese encephalitis virus (JEV) as a model, the optimized reverse transcription-polymerase chain reaction (ORTPCR) detects as few as 3-5 virions in 0.1 ml of whole blood specimens. The effectiveness of this assay system is confirmed by diagnosis of human hepatitis C viral (HCV) infection.

Animals↗

Production of nonstructural proteins of hepatitis C virus requires a putative viral protease encoded by NS3.

Hepatitis C virus (HCV) is a positive strand RNA virus with certain similarity to flaviviruses and pestiviruses. To examine the processing and possible assembly of HCV proteins, we constructed a recombinant vaccinia virus that expresses a full-length genomic RNA, infected chimp liver cells with the virus, and analyzed HCV-related protein products by immunofluorescent antibody staining and Western blot detection with mouse monoclonal antibodies. The putative core, envelope, and NS1 and NS3 proteins that yielded from this recombinant were 22, 32, 53 to 58, and 65 kDa in size, respectively. The NS4 protein was unexpectedly small, with an estimated molecular weight of 7 kDa, and the NS5 protein was found to be further cleaved into 52-kDa NS5a and 58-kDa NS5b proteins, the latter of which contains a hallmark of RNA replicase. A point mutation in the putative protease domain of NS3 resulted in a failure in the production of NS3, NS4, NS5a, and NS5b, but coexpression of NS3 restored the proper processing of these proteins, demonstrating that NS3, the putative viral protease, is essential for the production of these nonstructural proteins. Thus, HCV strikingly resembles pestiviruses in the size and the processing mode of the nonstructural proteins, particularly NS4 and NS5.

Animals↗

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↗