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Biomedical subjects

K Fukui

Publications and source records attributed to K Fukui.

At least 37 records · Page 2Linked to original sources

Genomic organization of the S locus: Identification and characterization of genes in SLG/SRK region of S(9) haplotype of Brassica campestris (syn. rapa).

In Brassica, two self-incompatibility genes, encoding SLG (S locus glycoprotein) and SRK (S-receptor kinase), are located at the S locus and expressed in the stigma. Recent molecular analysis has revealed that the S locus is highly polymorphic and contains several genes, i.e., SLG, SRK, the as-yet-unidentified pollen S gene(s), and other linked genes. In the present study, we searched for expressed sequences in a 76-kb SLG/SRK region of the S(9) haplotype of Brassica campestris (syn. rapa) and identified 10 genes in addition to the four previously identified (SLG(9), SRK(9), SAE1, and SLL2) in this haplotype. This gene density (1 gene/5.4 kb) suggests that the S locus is embedded in a gene-rich region of the genome. The average G + C content in this region is 32.6%. An En/Spm-type transposon-like element was found downstream of SLG(9). Among the genes we identified that had not previously been found to be linked to the S locus were genes encoding a small cysteine-rich protein, a J-domain protein, and an antisilencing protein (ASF1) homologue. The small cysteine-rich protein was similar to a pollen coat protein, named PCP-A1, which had previously been shown to bind SLG.

Amino Acid Sequence↗

Leukocyte function-associated antigen-1 expression on decidual natural killer cells in patients with early pregnancy loss.

A large number of CD56(bright) natural killer (NK) cells, which comprise a very small fraction of peripheral blood lymphocytes, appear in the endometrium during the late secretory phase and early pregnancy. These cells are thought to immunologically maintain or inhibit pregnancy. However, the details regarding their contribution to the immuno-elimination systems of embryonic cells or decidual stromal cells remain unclear. Recently, leukocyte function-associated antigen-1 (LFA-1) was shown to play a critical role in the regulation of NK cytolysis in peripheral blood lymphocytes. We speculated that LFA-1 on the decidual CD56(bright) NK may be involved in the regulation of pregnancy. The expression of LFA-1 on the decidual CD56(bright) NK cells was analysed using flow cytometry with fluorescent monoclonal antibodies; CD56 (NKH1), CD16 (Fcg-R3) and CD11a (LFA-1 alpha-chain). In comparison with non-pregnant endometrium during the late secretory phase, the subpopulation of CD56(bright)CD16(-) cells in decidual lymphocytes was significantly increased during normal pregnancy, but was less than that in early pregnancy loss (P < 0.05). Furthermore, the number of CD56(bright) NK cells expressing LFA-1 was significantly higher in early pregnancy loss, and the late secretory phase, than during normal pregnancy (P < 0.05). Our results indicate that up-regulation of LFA-1 on CD56(bright) NK cells is related to spontaneous abortion or the onset of menstruation.

Abortion, Spontaneous↗

Structure and enzymatic properties of genetically truncated forms of the water-insoluble glucan-synthesizing glucosyltransferase from Streptococcus sobrinus.

Glucosyltransferase-I (GTF-I: 175 kDa) of a cariogenic bacterium, Streptococcus sobrinus 6715, mediates the conversion of water-soluble dextran (alpha-1,6-glucan) into a water-insoluble form by making numerous alpha-1,3-glucan branches along the dextran chains with sucrose as the glucosyl donor. The structures and catalytic properties were compared for two GTF-I fragments, GTF-I' (138 kDa) and GS (110 kDa). Both lack the N-terminal 84 residues of GTF-I. While GTF-I' still contains four of the six C-terminal repeats characteristic of streptococcal glucosyltransferases, GS lacks all of them. Electron microscopy of negatively stained samples indicated a double-domain structure for GTF-I', consisting of a spherical head with a smaller spherical tail, which was occasionally seen as a long extension. GS was seen just as the head portion of GTF-I'. In the absence of dextran, both fragments simply hydrolyzed sucrose with similar K(m) and k(cat) values at low concentrations (<5 mM). At higher sucrose concentrations (>10 mM), however, GTF-I' exhibited glucosyl transfer activity to form insoluble alpha-1, 3-glucans. So did GS, but less efficiently. Dextran increased the rate and efficiency of the glucosyl transfer by GTF-I'. On removal of the C-terminal repeats of GTF-I' by mild trypsin treatment, this dextran-stimulated transfer was completely lost and the dextran-independent transfer became less efficient. These results indicate that the N-terminal two-thirds of the GTF-I sequence are organized as a structurally and functionally independent domain to catalyze not only sucrose hydrolysis but also glucosyl transfer to form alpha-1,3-glucan chains, although not efficiently; the C-terminal repeat increases the efficiency of the intrinsic glucosyl transfer by the N-terminal domain as well as rendering the whole molecule primer-dependent for far more efficient insoluble glucan synthesis.

Bacterial Proteins↗

Incidence of Prevotella intermedia and Prevotella nigrescens carriage among family members with subclinical periodontal disease.

We established a typing system for Prevotella intermedia and Prevotella nigrescens using the combination of PCR ribotyping and arbitrarily primed PCR (AP-PCR) fingerprinting and applied this system to the study of intrafamilial incidence of these species in the oral cavity. PCR ribotyping followed by subtyping by AP-PCR fingerprinting was applied to each type strain of P. intermedia and P. nigrescens and 54 isolates (32 isolates of P. intermedia and 24 isolates of P. nigrescens) from extraoral infections, resulting in an excellent discriminatory power (discrimination index, 0.99) for both species. A total of 18 subjects from six families, with the subjects from each family comprising the mother, the father, and a child who had subclinical early-stage to moderate adult periodontitis or simple gingivitis and who carried P. intermedia or P. nigrescens, or both, were enrolled in the study of intrafamilial carriage. When 20 colonies per specimen of subgingival plaque, if available, were picked from primary culture, 115 P. intermedia and 178 P. nigrescens isolates were recovered from the 18 subjects. Among the subjects studied, family members shared the same subtype strain(s) but non-family members did not. Multiple subtypes were found in 8 (57%) of the 14 P. nigrescens-positive subjects but in only 3 (27%) of the 11 P. intermedia-positive subjects; the difference was, however, not statistically significant (P = 0.14). These results suggest that the combination of PCR ribotyping and AP-PCR fingerprinting is well suited for the epidemiological study of P. intermedia and P. nigrescens and that each family seems to carry a distinct subtype(s) of these species.

Adolescent↗

Use of PCR and sodium dodecyl sulfate-polyacrylamide gel electrophoresis techniques for differentiation of Prevotella intermedia sensu stricto and Prevotella nigrescens.

Primers were designed from 16S rRNA sequences of Prevotella intermedia sensu stricto and Prevotella nigrescens and were used to discriminate these two species by PCR. The results were compared with those from the PCR technique using primers designed from arbitrarily primed PCR products by Guillot and Mouton (E. Guillot and C. Mouton, J. Clin. Microbiol. 35:1876-1882, 1997). The specificities of both assays were studied by using P. intermedia ATCC 25611, P. nigrescens ATCC 33563, 174 clinical isolates of P. intermedia sensu lato, and 59 reference strains and 58 clinical isolates of other Prevotella species and/or common oral flora. In addition, the usefulness and reliability of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the differentiation of the two species were examined by comparing the results with those from PCR assays. The controversial lipase test for distinguishing these species was also carried out. Unambiguous differentiation was made by both PCR assays, and the results matched each other. The SDS-PAGE assay was found to misidentify a few strains tested, compared with the results of PCR assays. The lipase test was positive for both species, including the reference strains of P. intermedia and P. nigrescens. We conclude that both PCR assays are simple, rapid, reliable, and specific methods which could be used in clinical studies and that the lipase test is not valuable in the differentiation. The reliable discrimination of the two species by SDS-PAGE is questionable.

Bacterial Typing Techniques↗

Distribution of TGG repeat-related sequences in 'Trovita' orange (Citrus sinensis Osbeck) chromosomes

The clone pAS"C" is a sequence related to M13 phage minisatellite sequences isolated from bovine DNA. It contains TGG repeats, and related sequences are abundant in the Citrus genome. Fluorescent in situ hybridization (FISH) signals detected using this clone as a probe showed that the TGG repeat-related sequences are found on all the Citrus chromosomes, but are not found in Citrus-specific CMA+/DAPI- heterochromatic regions located at the extreme ends of each chromosome. These data suggest that the TGG-repeated sequences are evolutionarily conserved and that the CMA+/DAPI- heterochromatic regions were added to the chromosome ends at a recent stage in Citrus evolution.

Journal Article↗

Oral administration of sepimostat mesilate prevents acute alcohol pancreatic injury in rats.

The preventive effect of a novel synthetic serine protease inhibitor, sepimostat mesilate (sepimostat), on acute alcohol pancreatic injury, induced by exocrine hyperstimulation and ethanol administration, was assessed and compared with that of a similar protease inhibitor, camostat mesilate (camostat). Conscious rats were infused with 1 microg mL(-1) h(-1) caerulein intravenously for 6 h and with 0.1 g mL(-1) h(-1) ethanol for 9 h, with the latter infusion beginning 3 h after the start of the caerulein infusion. Sepimostat or camostat was administered orally 1 h before the caerulein infusion. Rats infused with caerulein plus ethanol showed increased plasma amylase and lipase activities, and aggravated pancreatic interstitial oedema when compared with rats given caerulein alone. Sepimostat at 10 and 30 mg kg(-1) prevented the increase in plasma amylase and lipase activities caused by caerulein plus ethanol infusion. Sepimostat at 30 mg kg(-1) suppressed the histological change. Camostat did not show any preventive effects at the equivalent dose. When conscious rats were infused with 1 microg mL(-1) h(-1) caerulein alone intravenously for 6 h, plasma amylase and lipase activities were increased compared with rats given saline. Neither drug prevented the increase in these activities at 30mg kg(-1). Our results suggest that sepimostat has superior preventive effects on alcohol-induced acute pancreatic injury compared with camostat. Sepimostat may thus be a useful drug in the therapy of alcohol-induced pancreatitis.

Acute Disease↗

[A case report of organic solvent abuse with amotivational syndrome].

We investigated an organic solvent abuser who developed amotivational syndrome employing neuropsychological examination (Rorschach test, Bender Gestalt test and Benton visual retention test), electroencephalography, magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The patient manifested a disability to maintain a goal-orient mental activity, immature reality testing and poor set shifting, which suggest frontal lobe dysfunction, as we have reported before in neuropsychological examination. In this case, single photon emission computed tomography (SPECT) also revealed a decrease of regional cerebral blood flow (rCBF) in the medial frontal lobe. These results may suggest a contribution of frontal lobe (especially medial frontal lobe) dysfunction to the pathogenesis of amotivational syndrome due to organic solvent abuse.

Adult↗

[A case report of male alcoholics treated the left replacement prosthesis on account of the idiopathic avascular necrosis of the left femoral head].

Idiopathic necrosis of the femoral head is already described associated with alcoholism. However, it is unusual to meet alcoholic patient with idiopathic necrosis of the femoral head in psychiatric hospital. In this report, we describe about the psychiatric treatment of an alcoholic male patient who complicated idiopathic necrosis of the femoral head. He begun drinking a large amount of alcohol at the age of 20. After 32 years old, he repeated admission to psychiatric hospitals for the treatment against alcohol dependence. At the age of 35, he felt left hip pain. At 36 years old, the illness was diagnosed as idiopathic necrosis of the femoral head and osteotomy was performed. After the operation, he did not keep the direction to keep a rest and not to drink. At last, total replacement arthroplasty was undergone. All through the treatment, we supported the patient to participate in group therapy and Alcoholics Anonymous, and approached directively and supportively to gain an insight about problems of drinking. As a result, after the last operation he hoped psychiatric treatment of his own will and began to gain insight gradually about his own alcoholic problems. This case emphasizes the necessity of psychotherapeutic approach and treatment programs for alcohol dependence and its physical complications.

Adult↗

[Mental and physical symptoms in alcoholics after alcohol withdrawal--comparing with involutional melancholia patients].

As a factor of recurrence of drinking in patients with alcoholic dependence, emotional disorders accompanied by alcohol dependence has been noted in many reports. Particularly, it is noted to be very likely that depression after abstinence is an incentive to re-start drinking. In this study, we investigated depressive feeling in aspects of psychiatric and physical subjective symptoms after abstinence in patients with alcohol dependence, and compared the symptoms with those in patients with involutional depression. On analysis of the major component of psychiatric subjective symptoms, a sense of alienation, emotional instability, anxiety, and aggressiveness were observed. In involutional depression, depressive feeling, somnipathy, anxiety, self accusation/sense of guilt, delusion of culpability were observed. On analysis of the major component of physical subjective symptoms, autonomic nervous symptoms accompanied by feebleness, hysterical neurosis-like autonomic nervous symptoms, reduced sexual libido, anorexia, hydrodipsia/sweating were observed. Similarly, in patients with involutional depression, hysterical neurosis-like autonomic nervous symptoms, anorexia, elevation of tonus, general malaise, and hydrodipsia were noted. Differences in status were emphasized in comparison between the two groups in both analyses. Unlike involutional depression that exhibits the current features of depression, patients with alcohol dependence showed a sense of alienation, emotional instability, anxiety, and aggressiveness, reflecting self-uncertainty and loss of self-respect. Drinking may be re-started to relieve or reduce tension and frustration in such conditions.

Alcoholism↗

Molecular cloning and characterization of the noncatalytic subunit of the Rab3 subfamily-specific GTPase-activating protein.

We recently purified and characterized from rat brain a GTPase-activating protein (GAP) specific for the Rab3 small G protein subfamily implicated in Ca2+-dependent exocytosis. Rab3 GAP showed two bands with Mr of about 130,000 (p130) and 150,000 (p150) on SDS-polyacrylamide gel electrophoresis. p130, but not p150, showed the catalytic activity. Because p150 was likely the subunit of Rab3 GAP, here we cloned the cDNA of p150, determined its primary structure, and characterized it. The tissue and subcellular distribution patterns of p150 and p130 were similar, and both the proteins were enriched in the synaptic soluble fraction. p150 was co-immunoprecipitated with p130 from this fraction. Recombinant p150 formed a heterodimer with recombinant p130 as estimated by sucrose density gradient ultracentrifugation. Recombinant p150 neither showed the Rab3A GAP activity nor affected the activity of recombinant p130. When p150 and p130 were co-expressed in the cells, the subcellular localization of each protein did not change. These results indicate that p150 is the noncatalytic subunit of Rab3 GAP.

Amino Acid Sequence↗

Visualization of the Brassica self-incompatibility S-locus on identified oilseed rape chromosomes.

Seventy years after Karpechenko [15] first reported the accurate chromosome number of oilseed rape (Brassica napus L., 2n=38), we have developed a quantitative chromosome map of rape using computer imaging technology. The capacity to identify individual rape chromosomes will facilitate a wide range of genetic studies. Here we demonstrate the use of imaging methods in combination with fluorescence in situ hybridization to localize, on identified chromosomes, the single copy S-locus glycoprotein and S-locus-related genes involved in the self-incompatibility system of Brassica. These techniques have a broader application in plant genome research involving the mapping of single-copy genes and markers, irrespective of the plant species.

Brassica↗

Physical mapping of unique nucleotide sequences on identified rice chromosomes.

A physical mapping method for unique nucleotide sequences on specific chromosomal regions was developed combining objective chromosome identification and highly sensitive fluorescence in situ hybridisation (FISH). Four unique nucleotide sequences cloned from rice genomic DNAs, varying in size from 1.3 to 400 kb, were mapped on a rice chromosome map. A yeast artificial chromosome (YAC) clone with a 399 kb insert of rice genomic DNA was localised at the distal end of the long arm of rice chromosome (1q2.1) and a bacterial artificial chromosome (BAC) clone (180 kb) containing the rice leaf blast-resistant gene (Pi-b) was shown to occur at the distal end of the long arm of chromosome 2 (2q2.1). A cosmid (35 kb) with the resistance gene (Xa-21) against bacterial leaf blight was mapped on the interstitial region of the long arm on chromosome 11 (11q1.3). Furthermore a single RFLP marker, 1.29 kb in size, was mapped successfully to the distal region of the long arm of rice chromosome 4 (4q2.1). For precise localisation of the nucleotide sequences within the chromosome region, image analyses were effective. The BAC clone was localised to the specific region, 2q2.1:96.16, by image analysis. The result was compared with the known location of the BAC clone on the genetic map and the consistency was confirmed. The effectiveness and reliability in physically mapping nucleotide sequences on small plant chromosomes achieved by the FISH method using a variety of probes was unequivocally demonstrated.

Base Sequence↗

Condensation pattern (CP) analysis of plant chromosomes by an improved chromosome image analysing system, CHIAS III.

The third-generation chromosome image analysing system (CHIAS III) was developed by using an ordinary personal computer with public domain imaging software, the NIH Image. An uneven condensation pattern (CP) appearing on small sugarcane chromosomes at the mitotic prometaphase stage was analysed and a quantitative chromosome map or idiogram was developed by using CHIAS III. The analysis consists of three major steps as follows: (1) manipulation of original chromosome images and measurement of CP or numerical data of the CP; (2) calculation of an averaged CP for homologous chromosomes; and (3) development of an idiogram based on the averaged CP. The CP has been analysed quantitatively by using the first- and the second-generation chromosome image analysing systems with hard- and software specific to the systems. The data obtained using CHIAS III are consistent with those obtained with the chromosome image analysing systems previously developed.

Chromosomes↗

Experimental creation of fusiform carotid artery aneurysms using vein grafts in rats.

OBJECTIVE: We developed an in vivo model of growing fusiform aneurysms, using vein grafts to the rat carotid artery. This aneurysm model might demonstrate the pathological features of the development and growth of aneurysms to become giant aneurysms. METHODS: Placement of an interposed femoral vein graft to restore carotid artery flow was performed in Wistar rats. On Day 21, 75% of the grafts (mean diameter, 1.6 mm) were found to be dilated to resemble fusiform aneurysms (mean diameter, 5.82 mm), and 53% of these were giant. Quantitative analysis of the histological findings was performed using image-analyzing software. RESULTS: Histological findings were similar to those for human intracranial giant aneurysms. The average length of the initial grafts in the aneurysm group was 9.1+/-1.9 mm, and grafts were significantly longer and more tortuous than in the normal graft group (6.4+/-0.8 mm) (P = 0.01). Cross-sectional areas of the aneurysms (mean, 18.9 mm2) were significantly correlated with the following: 1) the area of intra-aneurysmal thrombosis (mean, 11.1 mm2) (P < 0.0001); 2) the number of intrathrombotic vascular channels (P = 0.005); and 3) the area of dissection, with hemorrhage, between the thrombus and the wall of the aneurysm (mean, 0.72 mm2) (P = 0.0013). Scanning electron microscopic examination showed evidence of endothelial damage associated with growth of the aneurysms. CONCLUSION: Recurrent hemorrhaging from intrathrombotic vascular channels caused dissection between the thrombus and the aneurysm wall, which led to growth of the experimental aneurysms to giant aneurysms. With this model, we demonstrated the growth mechanism of giant fusiform aneurysms.

Aortic Dissection↗

Molecular characterization of low-molecular-weight component protein, Flp, in Actinobacillus actinomycetemcomitans fimbriae.

Fimbriae preparation from Actinobacillus actinomycetemcomitans was found to contain an abundant low-molecular-weight protein (termed Flp) with an apparent molecular mass of approximately 6.5 kDa, in addition to a small amount of 54-kDa protein. Immunogold electron microscopy localized the Flp protein at the bacterial fimbriae but not at the cell surface. The DNA fragment including the flp gene was cloned from A. actinomycetemcomitans 304-a and its nucleotide sequence was determined. An open reading frame of the flp gene was composed of 225 bp encoding a protein of 75 amino acids. Comparison of the translated amino acid sequence with the sequence of native Flp determined by Edman degradation indicated that the N-terminal part of 26 amino acids is leader peptide. The N-terminal sequence of mature Flp exhibited some similarity to type-IV pilin. Furthermore, the processing site of premature Flp is also similar to that of type-IV prepilin, and a gene encoding a protein homologous to type-IV prepilin-like protein leader peptidase was found downstream of the flp gene. These findings indicate that Flp is the major component protein of A. actinomycetemcomitans fimbriae.

Aggregatibacter actinomycetemcomitans↗