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Biomedical subjects

H Fujimoto

Publications and source records attributed to H Fujimoto.

At least 163 records · Page 9Linked to original sources
PubMed1993

A novel murine zinc finger gene mapped within the tw18 deletion region expresses in germ cells and embryonic nervous system.

A novel zinc finger gene, designated NT fin12, belonging to the C2H2-Krüppel-type gene family was isolated from a newborn mouse testis cDNA library by using zinc finger consensus motif probes. Northern blot analyses showed that NT fin12 mRNA was expressed during the meiotic prophase of spermatogenesis and in embryogenesis. Transcripts were localized by in situ hybridization in spermatogonia and in early spermatocytes, and in testis cords in the genital ridge as well as in oocytes and follicle cells in the ovary. In midgestational embryos at 8.5-13.5 days postcoitum, transcripts were present in the neuroectoderm, and they were progressively restricted to peripheral ganglia derived from neural crest cells and neural placodes and to the motor nerve cells in the central nervous system. Taken together these results indicate that NT fin12 functions during germ cell development and also plays a role in the specification of a subpopulation of neuroectodermal cells. Genetic linkage analyses revealed that the NT fin12 locus mapped to the deletion region of the tw18 haplotype on mouse chromosome 17.

Amino Acid Sequence↗
PubMed1993

A rho-like protein is involved in the organisation of the contractile ring in dividing sand dollar eggs.

Sand dollar eggs were microinjected with botulinum C3 exoenzyme, an ADP-ribosyltransferase from Clostridium botulinum that specifically ADP-ribosylates and inactivates rho proteins. C3 exoenzyme microinjected during nuclear division interfered with subsequent cleavage furrow formation. No actin filaments were detected in the equatorial cortical layer of these eggs by rhodamine-phalloidin staining. When microinjected into furrowing eggs, C3 exoenzyme rapidly disrupted the contractile ring actin filaments and caused regression of the cleavage furrows. C3 exoenzyme had no apparent effect on nuclear division, however, and multinucleated embryos developed from the microinjected eggs. By contrast, C3 exoenzyme did not affect the organisation of cortical actin filaments immediately after fertilisation. Only one protein (molecular weight 22,000) was ADP-ribosylated by C3 exoenzyme in the isolated cleavage furrow. This protein co-migrated with ADP-ribosylated rhoA derived from human platelets when analysed by two-dimensional gel electrophoresis. These results strongly suggest that a rho-like, small GTP-binding protein is selectively involved in the organisation and maintenance of the contractile ring.

ADP Ribose Transferases↗
PubMed1993

Insect resistant rice generated by introduction of a modified delta-endotoxin gene of Bacillus thuringiensis.

As a first step towards development of insect resistant rice we have introduced a truncated delta-endotoxin gene, cryIA(b) of Bacillus thuringiensis (B.t.) which has specific biological activity against lepidopteran insects into a japonica rice. To highly express the cryIA(b) gene in rice the coding sequence was extensively modified based on the codon usage of rice genes. Transgenic plants efficiently expressed the modified cryIA(b) gene at both mRNA and protein levels. Bioassays using R2 generation plants with two major rice insect pests, striped stemborer (Chilo suppressalis) and leaffolder (Cnaphalocrosis medinalis), indicated that transgenic rice plants expressing the CryIA(b) protein are more resistant to these pests than untransformed control plants. Our results suggest that the B.t. endotoxin genes will be useful for the rational development of new rice varieties resistant to major insect pests.

Amino Acid Sequence↗
PubMed1993

Electron microscopic study of intercellular junctions in human gastric mucosa with special reference to their relationship to gastric ulcer.

The development of gap junctions in the human gastric mucosa has been examined to see if there is any relation to gastric ulcer. Freeze fracture replicas were prepared from the endoscopic biopsy specimens of 20 patients with gastric ulcer (15 men and five women, aged 49 (13) years) and seven healthy volunteers (four men and three women, aged 41 (19) years). Large fractured areas of lateral cell membranes of surface mucous cells were observed randomly at a direct magnification of 15,000 using electron microscopy. Small gap junctions were observed between gastric surface mucous cells in all healthy volunteers. Gap junctions in the patients with gastric ulcer were significantly fewer than in the healthy volunteers. In addition, gap junctions in patients with recurrent ulcer were significantly fewer than in those with first onset ulcer. There was no obvious relationship between age and the development of gap junctions in patients with gastric ulcer or in healthy volunteers. In areas of intestinal metaplasia, gap junctions were occasionally seen between absorptive cells of the villi, but not in the lateral membranes of goblet cells. These findings suggest that loss of intercellular communication via gap junctions is associated with gastric ulcer formation.

Female↗
PubMed1993

Identification of immunosuppressive components of a mushroom, Lactarius flavidulus.

Three metabolites having a suppressive effect on proliferation of mouse lymphocytes stimulated with mitogens such as concanavalin A (Con A) and lipopolysaccharide (LPS) were isolated from a mushroom, Lactarius flavidulus, and identified as geranylphenols, flavidulols A, B and C, respectively, which had previously been isolated from the same mushroom. The IC50 values of flavidulols A, B and C were found to be 8.9, 4.9 and 36.3 micrograms/ml against Con A-induced proliferation of mouse lymphocytes, and 6.7, 3.9 and 28.3 micrograms/ml against LPS-induced proliferation, respectively.

Agaricales↗
PubMed1993

[Tumor recurrence and grade and/or stage progression in low grade tumor. Analysis of 154 patients with superficial transitional cell carcinoma of the bladder].

The clinicopathological findings of 154 patients with initially superficial (stage pTa or pT1) transitional cell carcinoma in the bladder were analyzed to study risk factors for tumor recurrence or progression in grade and/or stage of the low grade tumor. The number, size, grade and stage of tumor at the first presentation were the significant predictors for the first tumor recurrence. However, only the tumor grade and size at the first recurrence were the predictors for the second recurrence. In 19 (33%) of 57 patients with recurrence, low grade superficial tumor progressed in tumor grade and/or muscle invasion. The progression of low grade tumor correlated with short tumor free intervals and tumor size. Grade and/or stage progression was observed in 14% of the tumor of 1 cm or less in diameter, whereas in 42% of the tumor more than 1 cm in diameter (Chi-square test: p < 0.25). These results indicate that tumor grade and size are important predictors for recurrences. Short tumor free intervals and sizes of tumors in the second recurrence are significant predictors for grade and/or stage progression in low grade superficial cancer.

Adult↗
PubMed1993

Transitional cell carcinoma of the upper urinary tract: analysis of morphology and distribution for surgical management.

Two series of transitional cell carcinomas (TCC), one including 49 renal pelvic and/or ureteral cancers and the other 29 bladder cancers with concomitant ureteral involvement, were reviewed to establish the criteria for nephron-sparing surgery and for selecting the most appropriate surgical intervention for TCCs at the ureterovesical junction. The following categorization of tumors was made possible by histological mappings of step-sectioned surgical specimens from various surgical modes: 1) low grade papillary superficial tumor, 2) high grade papillary or non-papillary tumor with adjacent or skipped carcinoma in situ (CIS), 3) high grade non-papillary invasive tumor without CIS, 4) high grade papillary superficial tumor without CIS. We can, by comparing postoperative clinical courses, select the mode of surgery in the following manner: 1) nephron-sparing surgery could be indicated in cases of low grade papillary tumor so far as a complete resection is possible; 2) in a case of high grade papillary or non-papillary tumor with adjacent or skipped CIS, extended resection of the urinary tract is required; 3) in a case of high grade non-papillary tumor without CIS, complete en bloc resection of the tumor site, including surrounding organs, will be necessary. The possibility of organ-sparing surgery for early stage cancer without CIS at the ureterovesical junction has been suggested. Preoperative consideration of the above classifications for conservative surgery is also discussed.

Adult↗
PubMed1993

[An evaluation of tumor markers and risk factors in mass screening for various cancers].

The borderline values of tumor markers and the clarification of risk factors for cancer are problems to be solved in the development of mass screening tests for various cancers. A tiny abnormality may be overlooked in an evaluation based upon traditional reference standards obtained by surveying healthy subjects. Both negative and positive values are required in mass screening for various cancers. That is, cut-off values should minimize the incidence of false negatives and false positives in the screening test. A modified combination assay using tumor markers and risk factors was used to screen 967 healthy subjects over age 50 for nonspecific cancers and the results were analyzed. Positive rates based on ordinary cut-off values for each tumor marker were about 6 to 7% in CEA, CA19-9 and BFP, 2.7% in SPAN-1, 1.3% in PAP, and less than 1% in AFP, SCC, CA125 and NCC -ST-439. For pepsinogen, a risk factor of various cancers especially in the digestive tract, the cut-off value was determined as the mean-SD in 967 healthy subjects over 50 years old. That is, the cut-of value for pepsinogen I was 18.7 ng/ml. A lower value was found in 149 subjects (15.4%). The cut-off value for pepsinogen II was 7.4 ng/ml and a lower value was found in 227 subjects (23.5%). The cut-off value for the pepsinogen I/II ratio was 1.2 and 108 subjects showed lower values (11.2%). Positive cases were referred to specialists in various fields to detect the specific suspected cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Antibody dependent cell mediated cytotoxicity on human cervical carcinoma cell line, ME-180, with human monoclonal antibody.

A human monoclonal antibody (MCA), CLN-IgG, showed cytotoxic effect in vitro against the cervical carcinoma cell line, ME-180, by antibody dependent cell-mediated cytotoxicity (ADCC). To determine which fractions of cells in peripheral blood lymphocyte (PBL) mediate ADCC, PBL were separated with nylon wool column and sheep red blood cells (SRBC). Both adherent cells (monocyte) and non-T, non-B cells showed cytotoxicity by ADCC. Human non-T, non-B cells showed higher cytotoxic activity against ME-180 cells than monocytes. Furthermore murine effector cells were less effective in ADCC than human effector cells with human MCA.

Antibodies, Monoclonal↗
PubMed1992

Peritoneal mesothelioma: hypertrophic gastroepiploic and omental arteries identified by radioimmune angiography.

We report a first case of malignant peritoneal mesothelioma examined by radioimmune (RI) angiography with technetium-99m human serum albumin. The RI angiography clearly demonstrated the characteristic findings including hypertrophic gastroepiploic arteries and dilated omental branches. These findings may be very helpful in distinguishing malignant peritoneal mesotheliomas from peritoneal carcinomatosis.

Adult↗
PubMed1992

Expression of a mouse zinc finger protein gene in both spermatocytes and oocytes during meiosis.

In order to identify genes regulating meiosis, a mouse spermatocyte cDNA library was screened for sequences encoding proteins with C2H2-type zinc finger motifs which are typically expressed by the Drosophila Krüppel gene. Three new cDNAs were isolated, and they were designated CTfin33, CTfin51, and CTfin92. Among them, CTfin51 was selected for further study. The deduced amino acid sequence revealed seven zinc finger motifs in its C-terminal region. Northern blot and in situ hybridization showed CTfin51 mRNA expression in spermatocytes after the pachytene stage and in early stage round spermatids of prepuberal and adult males. Immunocytochemical staining with an antiserum against beta-gal-CTfin51 fusion protein was localized within nuclei of spermatocytes and spermatids. Oocyte nuclei after the pachytene stage also were immunoreactive for CTfin51 protein. Immunoblots revealed a band at M(r) 75,000 in protein extracts from the testis and the ovary. These results suggest that the CTfin51 gene encodes a DNA-binding regulatory protein functionally associated with meiosis in both male and female gametogenesis.

Amino Acid Sequence↗
PubMed1992

Splenic metastasis of hepatocellular carcinoma. Accumulation of Tc-99m HDP.

Considerable accumulation of Tc-99m HMDP was noted in a huge splenic mass in a 62-year-old man with hepatocellular carcinoma. An autopsy revealed a massive hemorrhage within the splenic metastasis. The splenic uptake of the radionuclide corresponded to the marked deposition of hemosiderin.

Carcinoma, Hepatocellular↗
PubMed1992

Parental methylation patterns of a transgenic locus in adult somatic tissues are imprinted during gametogenesis.

The methylation status of a mouse metallothionein-I/human transthyretin fusion gene was studied during gametogenesis in transgenic mice. In the adult tissues of this mouse line, the promoter region of the transgene on chromosome 11 is methylated when it is maternally inherited and undermethylated when it is paternally inherited. Germ cells from various developmental stages of gametogenesis were isolated, and their DNAs were assayed using methylation-sensitive restriction endonucleases and the polymerase chain reaction. Only low to nonexistent levels of transgene methylation were detected in germ cells from 14.5-day-old male and female fetuses irrespective of the parental origin of the transgene. This undermethylated state persisted in oocytes from newborn females as well as in testicular spermatogenic cells and sperm. By contrast, the transgene promoter was completely methylated in fully grown oocytes arrested at the first meiotic prophase. The endogenous metallothionein-I gene promoter, located on a different chromosome, remained undermethylated at all stages examined, consistent with previous findings reported for a typical CpG island. Taken together, the results suggest that parental-specific adult patterns of transgene methylation are established during gametogenesis.

Animals↗
PubMed1992

Correlation of axenic linkage groups with the position of the microtubule-organizing center in aggregating Dictyostelium.

Positioning of the microtubule-organizing center (MTOC) in Dictyostelium discoideum was found to be genetically regulated. We examined the wild-type strain NC-4 cells independently maintained in different laboratories, freshly recovered cells from spores stocked for over 20 years, the temperature-sensitive growth mutant HU49 isolated from NC-4, as well as strain V-12 which is the opposite mating-type to NC-4. During aggregation on nonnutrient agar plates, all these strains showed similar cell polarity, as defined by the alignment of the nucleus ahead of the MTOC. By contrast, in Ax2 and Ax3, axenic strains carrying axenic mutations on linkage groups II and III, the MTOC was usually positioned ahead of the nucleus. Cells containing axenic linkage group II but not III positioned the MTOC ahead of the nucleus. Conversely cell polarity of strains including axenic linkage group III but not II was similar to that of wild-type cells. Thus axenic linkage group II, probably axeC or other linked gene(s) not yet identified, is responsible for the location of the MTOC anterior to the nucleus during aggregation. The anterior positioning of the MTOCs was prevented by growth on bacteria in cells carrying both axenic linkage groups, but not in those carrying only axenic linkage group II.

Animals↗
PubMed1992

Isolation, identification and pharmacological studies on three toxic metabolites from a mushroom, Hebeloma spoliatum.

Three metabolites, tentatively named HS-A, -B and -C, were isolated from a mushroom, Hebeloma spoliatum, as the fatal toxic principles to mice. HS-A was identified as 3-acetyl-2-(3'-hydroxy-3'-methyl)glutarylcrustulinol, which has been isolated from Hebeloma crustuliniforme and H. sinapizans as a cytotoxic principle. HS-B and -C were deduced to be 3,21-diacetyl-2-(3'-hydroxy-3'-methyl)glutarylcrustulinol and 3-acetyl-2-(3'-hydroxy-3'-methyl)glutarylanhydrocrustulinol, respectively, from their chemical and spectral data. Intraperitoneal administration of HS-A, -B and -C at a dose of 100 mg/kg caused death after paralysis of the limbs in mice. The compounds caused relaxation of mouse small intestine contracted by acetylcholine chloride or barium chloride treatment in vitro. They appear to exhibit a papaverine-like relaxation effect.

Animals↗