Biomedical subjects

K Fukushima

Publications and source records attributed to K Fukushima.

At least 181 records · Page 10Linked to original sources

PubMed1998

Application of the resident plasmid integration technique to construct a strain of Streptococcus godronii able to express the Bacillus circulans cycloisomaltooligosaccharide glucanotransferase gene, and secrete its active gene product.

A novel transformation technique, resident plasmid integration, for the cloning of foreign DNA in oral streptococci was described recently (T. Shiroza and H.K. Kuramitsu, Plasmid 34 (1995) 85-95. This technique is based on the integration of linearized foreign genes by recombination-proficient bacteria onto a resident plasmid, if an appropriate selection marker is flanked by the same anchor sites present in the resident plasmid. Since the transforming vehicles for this system included a pUC-derived replication origin, the high level expression in Escherichia coli cells hindered the cloning of certain genes. In the present study, new plasmids were constructed, two resident plasmids, four integration plasmids, and four cloning plasmids, all of which possess the medium-copy number replication origin, p15A ori, isolated from pACYC177. The resident plasmids consisted of the following three components: the p15A ori (0.65-kb Bg/II fragment), the pVA380-1 basic replicon functional in mutans streptococci (2.5-kb BamHI fragment), and either an erythromycin resistance or a spectinomycin resistance gene (0.9- or 1.1-kb BamHI fragment, respectively). Most of the basic replicon of pVA380-1, except for the 3'-portion of the 0.2-kb region, in the resident plasmid was replaced with a kanamycin resistance gene to construct the four integration plasmids. Therefore, the upstream and downstream anchor sites for the double cross-over event in this new system were 0.65-kb p15A ori and the 0.2-kb portion of the 3'-end of pVA380-1 replicon, respectively. This system was used to clone the gene coding for cycloisomaltooligosaccharide glucanotransferase which produces cycloisomaltooligosaccharide, a potent inhibitor of oral streptococcal glucosyltransferase, isolated from Bacillus circulans chromosome, into Streptococcus gordonii, and its gene product was successfully secreted into the culture media. Plasmids described here should be useful tools for introducing heterologous DNA into resident plasmids following integration in oral streptococci.

Bacillus↗

PubMed1998

Generation of plasma cells from peripheral blood memory B cells: synergistic effect of interleukin-10 and CD27/CD70 interaction.

B cells can differentiate into the antibody-secreting cells, plasma cells, whereas the crucial signals that positively control the entry into the pathway to plasma cells have been unclear. Triggering via CD27 by CD27 ligand (CD70) on purified peripheral blood B cells yielded an increase in the number of plasma cells in the presence of interleukin-10 (IL-10). Differentiation into plasma cells by a combination of IL-10 and CD70 transfectants occurred in CD27+ B cells but not in CD27- B cells. Moreover, addition of IL-2 to the IL-10 and CD70-transfect activation system greatly induced differentiation into plasma cells. In the presence of only IL-2, IL-4, or IL-6, CD70 transfectants did not promote differentiation into plasma cells. On the other hand, CD40 signaling increased the expansion of a B-cell pool from peripheral blood B cells primarily activated by IL-2, IL-10, and anti-CD40 monoclonal antibody (MoAb). Finally, CD27 signaling also rescued B cells from IL-10-mediated apoptosis. These data demonstrate that CD27 ligand (CD70) is a key molecule to prevent the IL-10-mediated promotion of apoptosis and to direct the differentiation of CD27+ memory B cells toward plasma cells in cooperation with IL-10.

Adult↗

PubMed1998

Latency of saccades during smooth-pursuit eye movement in man. Directional asymmetries.

To examine the effects of smooth-pursuit eye movements on the initiation of saccades, their latency was measured when subjects initially fixated or pursued a target. In half of the block of trials, the fixation or pursuit target was extinguished 200 ms before the saccade target was illuminated (gap trials). Reduction of the mean saccade latency in the gap trials (the "gap effect") was evident even when the subjects were pursuing a moving target, consistent with previous observations. The effect of pursuit direction on saccade latency was also examined. Saccades in the same direction as the preceding pursuit (forward saccades) had shorter latencies than those in the opposite direction (backward saccades). This asymmetry was observed in both the gap and nongap trials. Although the forward-backward asymmetry was much smaller than the "gap effect", it was statistically significant in six of eight cases. These results suggest that the preparation of saccades is affected by smooth-pursuit eye movements.

Adult↗

PubMed1998

Early pulmonary resection for localized Mycobacterium avium complex disease.

BACKGROUND: Results of antituberculous chemotherapy for Mycobacterium avium complex disease remain disappointing. Pulmonary resection during an early stage of the disease, therefore, may be beneficial to patients whose disease is localized and who can tolerate a resectional operation. METHODS: Thirty-three patients with localized M avium complex disease underwent 33 pulmonary resections between 1979 and 1996. There were 17 males and 16 females, with a mean age of 50 years (range, 30 to 69 years). Lobectomy was performed in 26 patients, pleuropneumonectomy in 1, segmentectomy in 5, and wedge resection in 1. RESULTS: There was no operative mortality. After pulmonary resection, 31 (94%) patients attained sputum-negative status. Bronchopleural fistula occurred in one patient who underwent a right upper lobectomy. There were two late deaths. A patient with bronchopleural fistula died of respiratory failure two years postoperatively. Another patient died of an unknown cause 12 years postoperatively. Of the 31 patients with negative sputum status postoperatively, only 2 patients (6%) had relapse at 1 and 9 years after operation. CONCLUSIONS: We recommend that patients with this disease be considered for pulmonary resection as early as possible.

Adult↗

PubMed1998

Effects of surfactants on glucosyltransferase production and in vitro sucrose-dependent colonization by Streptococcus mutans.

The presence of Tween 80 in media was associated with a significant increase in three glucosyltransferases(GTFs)(I, SI and S), especially GTF-I, produced by Streptococcus mutans strain PS14, indicating that the surfactant is a major cause of the enhanced GTF production observed in cultures in M4 medium. Lecithin and Tween 20 also enhanced GTF-I production, while Triton X-100 depressed it. At a lot concentration of 0.00125%, Tween 80 enhanced markedly only GTF-I production and its effect reached maximum at a concentration of 0.0025%. Water-insoluble glucan synthesis and artificial plaque formation (in vitro sucrose-dependent colonization) by PS14 were significantly enhanced by the addition of Tween 80 at concentrations over 0.00125%. These results suggest that surfactants might vary the cariogenic potential of Strep. mutans even at low concentrations.

Bacterial Adhesion↗

PubMed1998

An EGF receptor-mediated signal attenuates the inhibitory effect of LPA on an adenylate cyclase activity.

A tyrosine kinase receptor-mediated and a heterotrimeric G protein-coupled receptor-mediated signals have been shown to evoke distinct intracellular signaling events. There has been increasing evidence that cross-talk exists between a tyrosine kinase receptor-mediated and a heterotrimeric G protein-coupled receptor-mediated signal transduction pathways. In the present study, we have studied effects of EGF receptor activation on activities of inhibitory G protein (Gi). We show that the amounts of Gi/Go ADP-ribosylated by islet-activating protein (IAP) increased by 30-40% in the membranes of Rat 1 fibroblast cells pretreated with EGF compared with those without pretreatment. When an effect of lysophosphatidic acid (LPA) stimulation on an adenylate cyclase activity was examined, LPA partly attenuated forskolin-stimulated adenylate cyclase activity via Gi because IAP pretreatment blocked the inhibitory effect of LPA. Pretreatment with EGF reduced the ability of LPA to inhibit the forskolin-stimulated adenylate cyclase activity, while the pretreatment did not have any effects on the forskolin-stimulated activity. Thus, the EGF receptor-mediated signal appears to cause the impairment of Gi function in Rat 1 fibroblast cells.

Adenylate Cyclase Toxin↗

PubMed1998

Passage to India: the search for genes causing autosomal recessive nonsyndromic hearing loss.

Hereditary hearing impairment affects approximately 0.05% of all children born in the United States. It is most commonly autosomal recessive, nonsyndromic, and monogenic [autosomal recessive nonsyndromic hearing loss (ARNSHL)]. Although the number of disease loci is not known, some estimates exceed 100. Using a strategy of homozygosity mapping to localize ARNSHL genes by screening consanguineous families for chromosomal regions that are homozygous by descent, we have mapped several genes in multiplex, nuclear, consanguineous families in Tamil Nadu, India. From the mean frequency of the ARNSHL genes in this population, the total number of disease genes is estimated to be 57.

Chromosome Mapping↗

PubMed1998

Sodium butyrate-induced liver-type alkaline phosphatase activity in a small intestinal epithelial cell line, IEC6.

Sodium butyrate is a well-recognized differentiating agent inducing alkaline phosphatase activity, one of the epithelial differentiation markers. When IEC6 cells, a nontransformed, small intestinal epithelial cell line, were cultured with butyrate, this substrate induced alkaline phosphate activity in a time- and dose-dependent fashion. However, the type of isoenzyme involved was a liver-type, not an intestinal-type. Electron microscopy revealed that the induced activity was strictly localized in the cytosol and not on the plasma membrane. However, disaccharidase activities, another kind of differentiation marker, were also enhanced by sodium butyrate. In addition, the positive cells demonstrating the presence of alkaline phosphatase activity were preferentially observed in tubular structures. These data show that butyrate-induced alkaline phosphatase activity is closely associated with differentiation-like phenomena in IEC6 cells, although the type of isoenzyme and cellular localization of the activity are different from those observed in mucosa.

Alkaline Phosphatase↗

PubMed1998

Immunohistochemical expression of ABH/Lewis-related antigens in primary breast carcinomas and metastatic lymph node lesions.

The expression of blood group antigens A, B, and H, as well as sialylated and nonsialylated forms of Lewis(a) and Lewis(x), was studied using immunohistochemical methods in normal and tumor tissues in the following cohort of patients: 51 patients with primary breast carcinoma, 13 with metastatic lymph node lesions, and 16 with benign tumors of the breast. As a control, normal tissue was obtained from a similar group of 22 patients with breast cancer. The noncancerous tissues expressed the same A/B/H antigens as the patients' red blood cells and also usually expressed Lewis-related antigens. Seventy-six percent of primary carcinomas failed to express the appropriate A/B/H antigens, and in one blood group A patient the tumor tissue expressed B antigen. In the metastatic lesions, Lewis(a)/sialyl Lewis(a) expression was reduced when compared with the primary tumors, but Lewis(x)/sialyl Lewis(x) antigens were still expressed. These results suggest a possible relationship between the metastatic behavior of the tumor and expression of the blood group antigens.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1998

Follow-up study of children with nephrotic syndrome treated with a long-term moderate dose of cyclosporine.

Because of its potential for chronic nephrotoxicity, the long-term use of cyclosporine A (CsA) as treatment for nephrotic syndrome (NS) is controversial. The clinical outcome of patients with NS treated with CsA is unclear. We retrospectively evaluated 35 children with idiopathic NS, 24 with steroid-dependent NS (SDNS), and 11 with steroid-resistant NS (SRNS), who received CsA therapy for more than 12 months (median, 23 months) at the dosage maintaining 50 to 120 ng/mL in trough level. For SDNS patients, CsA was added to prednisolone after complete remission was achieved. For SRNS patients, CsA was used in combination with alternate-day prednisolone. Initial renal histology showed minimal changes (MC) in 28 patients (including all of the patients with SDNS) and focal segmental glomerulosclerosis (FSGS) in seven patients. The patients were followed up for 2 to 10.5 years (median, 6.5 years) after the termination of the CsA therapy. In SDNS patients, the relapse rate, dosage of prednisolone, standard deviation score for height, and body mass index significantly improved during CsA treatment. The follow-up study showed the proportion of SDNS decreased to 13 of 24 (54%) patients. In SRNS patients, CsA therapy induced remission in 8 of 11 patients (73%) (complete remission in seven and incomplete remission in one). Six of 11 patients (55%) then became steroid sensitive. Post-therapy biopsies, performed in 13 patients (10 with SDNS and three with SRNS), showed mild stripped interstitial fibrosis in two SDNS patients (15%). Long-term CsA therapy in moderate doses was effective to the patients with SDNS and SRNS and low in incidence of nephrotoxicity. The long-term use of CsA appears to result in a decrease in the proportion of SDNS and acquisition of subsequent steroid responsiveness in SRNS.

Adolescent↗

PubMed1998

Localization of a gene for otosclerosis to chromosome 15q25-q26.

Among white adults otosclerosis is the single most common cause of hearing impairment. Although the genetics of this disease are controversial, the majority of studies indicate autosomal dominant inheritance with reduced penetrance. We studied a large multi-generational family in which otosclerosis has been inherited in an autosomal dominant pattern. Five of16 affected persons have surgically confirmed otosclerosis; the remaining nine have a conductive hearing loss but have not undergone corrective surgery. To locate the disease-causing gene we completed genetic linkage analysis using short tandem repeat polymorphisms (STRPs) distributed over the entire genome. Multipoint linkage analysis showed that only one genomic region, on chromosome 15q, generated a lod score >2.0. Additional STRPs were typed in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis gene.

Adult↗

PubMed1998

Lipoid pneumonia in lung cancer: radiographic and pathological features.

BACKGROUND: Obstructive pneumonia, a synonym for endogenous lipoid pneumonia, is often seen in patients with lung cancer, but details of this condition are still uncertain. METHODS: To elucidate the features of obstructive pneumonia, we radiopathologically studied 147 patients with lung cancer that had been resected. RESULTS: Gross inspection of the resected materials revealed evidence of endogenous lipoid pneumonia in 33 of the 147 patients with radiography that corresponded to obstructive pneumonia. We classified the 33 cases into three types as follows: (1) type I lipoid pneumonia, localized to the lung parenchyma distal to an airway obstructed by a tumor (23 cases); (2) type II lipoid pneumonia, features of type I lipoid pneumonia and consecutively spreading to the adjacent segment whose airway was not affected (five cases); (3) type III lipoid pneumonia, features of type II lipoid pneumonia and spreading to the isolated segments (five cases). Lipoid pneumonia was found in 16 of 89 (18%) adenocarcinoma cases and in 17 of 55 (31%) squamous cell carcinoma cases. In type I lipoid pneumonia, squamous cell carcinoma cases were predominant over adenocarcinoma cases (14 vs nine cases), but in type III lipoid pneumonia, adenocarcinoma cases predominated (four vs one case). Further, in cases of type III lipoid pneumonia, radiographs frequently revealed that lung cancers were cavitated. CONCLUSION: Lipoid pneumonia in lung cancer may be associated with factors that play a larger role than the cancer alone. It can be speculated that transbronchial dissemination of breakdown products of adenocarcinoma cells, including mucin, may contribute to the spread of the non-obstructive component of lipoid pneumonia, because the local physical effect of obstructed bronchus does not affect the non-obstructive component.

Adenocarcinoma↗

PubMed1998

Human dis3p, which binds to either GTP- or GDP-Ran, complements Saccharomyces cerevisiae dis3.

Saccharomyces cerevisiae Dis3p, which interacts with Ran/Gsp1p, complements Schizosaccharomyces pombe dis3-54. Consistent with the functional conservation of Dis3p in S. cerevisiae and S. pombe, the human ORF (accession number: R27667) was found to be highly homologous to yeast Dis3p. Based on its nucleotide sequence, we cloned a full-sized human DIS3 cDNA. The cloned human cDNA partly but significantly restored the temperature-sensitivity of S. cerevisiae dis3. Thus, Dis3p was found to be structurally and functionally conserved from yeast to mammals. Consistent with the report that S. cerevisiae Dis3p is identical to Rrp44p, which comprises the exosome involved in ribosomal RNA processing, S. cerevisiae Dis3p was found to be localized in the nucleolus. Similar to S. cerevisiae Dis3p, human Dis3p enhanced RCC1-stimulated nucleotide release from Ran, in a dose-dependent manner, and bound to GTP- or GDP-Ran.

Amino Acid Sequence↗

PubMed1998

Multiple carpal bone fractures in an eleven-year-old.

The successful treatment of a very rare case of multiple carpal bone fractures in a child is described. Fractures of the scaphoid, the capitate, and the hamate were treated with wire fixation, leading to good clinical results twenty-nine months after surgery.

Accidental Falls↗

PubMed1998

Rapid isolation of chromosomal DNA from oral streptococci and polymerase chain reaction-oriented restriction fragment-length polymorphism analysis for genetic heterogeneity.

We have extensively modified the published method for the lysis of gram-positive bacteria to isolate chromosomal DNA from only 1 ml of oral streptococcal overnight culture. Cells were incubated with lysozyme and R Nase A in the presence of polyethylene glycol. After centrifugation, cells were lysed with sodium dodecyl sulfate and proteinase K. Following ethanol precipitation, sodium dodecyl sulfate solution was added to the residue, and the pellet was completely dispersed by incubating at 65 degrees C. The chromosome was purified by extraction over phenol and chloroform. Two regions corresponding to the ribosomal RNA (rrn) operon and the glucosyltransferase gene were amplified using the chromosome from Streptococcus mutans and Streptococcus sobrinus by polymerase chain reaction (PCR). Genetic heterogeneity was assessed by restriction fragment-length polymorphism (PCR-RFLP). The PCR-RFLP analysis readily allowed us to subtype each strain, suggesting that the strategy presented here will provide a useful tool to verify epidemiological studies at the molecular level.

Base Sequence↗

PubMed1998

Long-term course of West syndrome associated with tuberous sclerosis.

We retrospectively analyzed the long-term clinical profiles of 47 patients with West syndrome (WS) associated with tuberous sclerosis (TS) the follow-up study for >10 years showed that WS developed into epilepsies of various types in all patients. Their final diagnoses were symptomatic generalized epilepsy (SGE: 29 patients, 62%), symptomatic partial epilepsy (PE: 14 patients, 30%), and undetermined epilepsy (UE: 4 patients, 8%). Eighty-five percent of all patients continued to show the same types of epilepsy that they had at their first examination, but in 15% the diagnosis had to be revised at the end of the follow-up period. The outcome of seizures was unfavorable for the SGE group. In the PE group, however, seizures were controlled in 9 (64%) of the 14 patients, and disturbances of daily activity were mild. In patients with WS associated with TS, the seizure outcome and social activity varied depending on the type of epilepsy or epileptic syndrome that developed from WS. The complicated clinical developments from WS with TS multiple cortical tubers related to epileptogenesis in addition to impairment of brain development.

Adolescent↗

PubMed1998

Atrial electrograms and activation sequences in the transition between atrial fibrillation and atrial flutter.

INTRODUCTION: The electrophysiologic mechanism of atrial fibrillation (AF) has a wide spectrum, and it seems that some atrial regions are essential for the occurrence of a particular type of AF. We focused on one type of AF: AF associated with typical atrial flutter (AFL), which was right atrial (RA) arrhythmia, and sought to investigate intra-atrial electrograms and activation sequences in the transition between AF and AFL. METHODS AND RESULTS: Intra-atrial electrograms and activation sequences in the RA free wall and the septum were evaluated in the transition between AF and AFL in seven patients without organic heart disease (all men; mean age 57+/-11 years). In five episodes of the conversion of AFL into AF, the AFL cycle length was shortened (from 211+/-6 msec in stable AFL to 190+/-15 msec before the conversion, P, 0.001). Interruption of the AFL wavefront and an abrupt activation sequential change induced by a premature atrial impulse resulted in fractionation and disorganization of the septal electrograms. During sustained AF, septal electrograms were persistently fractionated with disorganized activation sequences. However, the RA free-wall electrograms were organized, and the activation sequence was predominantly craniocaudal rather than caudocranial throughout AF. In 12 episodes of the conversion of AF into AFL, the AF cycle length measured in the RA free wall increased (from 165+/-26 msec at the onset of AF to 180+/-24 msec before the conversion, P, 0.001). AFL resumed when fractionated septal electrograms were separated and organized to the caudocranial direction, despite the RA free-wall electrograms remaining discrete and sharp with an isoelectric line. CONCLUSION: Changes of the electrogram and activation sequence in the atrial septum played an important role in the transition between AF and AFL.

Adult↗

PubMed1998

Volatile fatty acid, metabolic by-product of periodontopathic bacteria, induces apoptosis in WEHI 231 and RAJI B lymphoma cells and splenic B cells.

The ability of butyric acid, an extracellular metabolite from periodontopathic bacteria, to induce apoptosis in murine WEHI 231 cells, splenic B cells, and human RAJI cells was examined. The culture filtrate of Porphyromonas gingivalis, Prevotella loescheii, and Fusobacterium nucleatum, which contains high a percentage of butyric acid, induced DNA fragmentation in WEHI 231 cells. Volatile fatty acid, especially butyric acid, significantly suppressed B-cell viability in a concentration-dependent fashion. The DNA fragmentation assay indicated that butyric acid rapidly induced apoptosis in WEHI 231 cells (with 1.25 mM butyric acid and 6 h after treatment), splenic B cells (with 1.25 mM butyric acid), and RAJI cells (with 2.5 mM butyric acid). Incubation of WEHI 231 cells with butyric acid for 16 h resulted in the typical ladder pattern of DNA fragmentation and the apoptoic change such as chromatin condensation and hypodiploid nuclei. Cell cycle analysis implied that butyric acid arrested the cells at the G1 phase. The inhibitory assay suggested that butyric acid-induced apoptosis of WEHI 231 and splenic B cells was inhibited by W-7, a calmodulin inhibitor. These results suggest that calmodulin-dependent regulation is involved in the signal transduction pathway of butyric acid.

Animals↗