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Biomedical subjects

Y Kaneko

Publications and source records attributed to Y Kaneko.

At least 127 records · Page 7Linked to original sources
PubMed2000

Minimal damage during endoscopic latissimus dorsi muscle mobilization with the harmonic scalpel.

BACKGROUND: To reduce wound-related complications, a video-assisted surgical technique has been adopted for the mobilization of the latissimus dorsi muscle. We postulated that thermal damage to the muscle might be minimized by using a Harmonic Scalpel instead of electrocautery during this procedure. METHODS: Canine latissimus dorsi muscles were mobilized through a small incision, assisted by a videoscope. In 6 dogs, dissection with electrocautery was used to mobilize the latissimus dorsi muscle. In 6 other dogs, the Harmonic Scalpel was used. We compared operation times, wound infection rates, histologic changes in the muscles, and ease of handling between these groups. RESULTS: The operation time was significantly shorter in the Harmonic Scalpel group than in the electrocautery group (61.5 versus 106.5 minutes, p = 0.00014). The Harmonic Scalpel caused less histologic damage to the mobilized muscles and produced less vision-obscuring smoke. CONCLUSIONS: The Harmonic Scalpel shortens the operation, minimizes muscle damage, and facilitates the performance of video-assisted latissimus dorsi muscle mobilization.

Animals↗
PubMed2000

A case of papillary meningioma with a t(1;4)(q44;q21).

We report the results of cytogenetic analyses of three cases of meningiomas. The first case, a papillary meningioma, showed only one cytogenetic abnormality, 46,XX,t(1;4)(q44;q21). In contrast, the other two benign fibroblastic meningiomas showed loss of chromosome 22. Loss and/or rearrangement of chromosomes other than chromosome 22 appears to be associated with a more aggressive clinical course. It is suggested that a sole cytogenetic abnormality with a normal chromosome 22 indicates an atypical nature of meningioma.

Adult↗
PubMed2000

Dissection of signaling cascades through gp130 in vivo: reciprocal roles for STAT3- and SHP2-mediated signals in immune responses.

We generated a series of knockin mouse lines, in which the cytokine receptor gp130-dependent STAT3 and/or SHP2 signals were disrupted, by replacing the mouse gp130 gene with human gp130 mutant cDNAs. The SHP2 signal-deficient mice (gp130F759/F759 were born normal but displayed splenomegaly and lymphadenopathy and an enhanced acute phase reaction. In contrast, the STAT3 signal-deficient mice (gp130FXQ/FXXQ) died perinatally, like the gp130-deficient mice (gp130D/D). The gp130F759/F759 mice showed prolonged gp130-induced STAT3 activation, indicating a negative regulatory role for SHP2. Th1-type cytokine production and IgG2a and IgG2b production were increased in the gp130F759/F759 mice, while they were decreased in the gp130FXXQ/FXXQ immune system. These results indicate that the balance of positive and negative signals generated through gp130 regulates the immune responses.

Acute-Phase Reaction↗
PubMed2000

Japanese population data for two STR loci, HumTPO and HumLPL.

The two short tandem repeat (STR) systems, HumTPO and HumLPL, were investigated in blood samples obtained from approximately 800 unrelated Japanese individuals living in seven geographically different areas of Japan. Neither deviation from a Hardy-Weinberg equilibrium nor significant difference between the allele distributions was found among the seven Japanese populations in the two STR systems. These findings indicate that there is a general uniformity for both the STR loci in the Japanese population.

Journal Article↗
PubMed2000

Development of a host-vector system for Lactobacillus plantarum L137 isolated from a traditional fermented food produced in the Philippines.

Lactobacillus plantarum NC13, a strain derived from the L. plantarum strain L137 isolated from a traditional fermented food produced in the Philippines, contains 9 of the 15 plasmids in the parental strain. To construct a shuttle vector between L. plantarum and Escherichia coli for genetic manipulation of L137 and its derivatives, recombinant plasmids were prepared by using the 9-plasmid DNA mixture and an E. coli vector, pBluescript II SK+. The resultant recombinant plasmids were re-transferred to L. plantarum NCL21, an NC13-derived strain cured of 3 of the 9 plasmids, and 3 recombinant plasmids were obtained. The smallest plasmid, pRN14, contained a small cryptic plasmid, pLTK2, which is one of the plasmids in L. plantarum L137. Thus, the complete nucleotide sequence of pLTK2 was determined. The pLTK2 is 2295 bp in length, and has a major open reading frame of 951 bp. An encoded sequence of 317-amino acids showed extensive similarity with genes encoding replication protein (repA). A putative replication origin in pLTK2 also showed high homology to those of other gram-positive bacterial plasmids that replicate by the rolling circle mechanism. The shuttle vector pRN14 contained the erythromycin resistance gene and the ColE1 and pLTK2 replication origins. Transformation of L. plantarum strains with pRN14 by electroporation was optimized to give a transformation efficiency of 2 x 10(4) transformants/ mug plasmid. Plasmid pRN14 was stably maintained in strain NCL21, as well as in L. casei K95-5.

Journal Article↗
PubMed2000

A quantitative reverse transcriptase polymerase chain reaction method for the detection of leukaemic cells with t(8;21) in peripheral blood.

We evaluated the usefulness of a recently developed real-time reverse transcriptase polymerase chain reaction (RT-PCR) system to detect minimal residual diseases (MRD) in patients with acute myelogenous leukaemia (AML) with chromosomal translocation t(8:21). The method was simple, rapid and reproducible for the quantity of chimeric AML1-ETO (MTG8) transcripts. The ratio of the absolute copy number of a target gene (AML1-ETO) to a control gene (glyceraldehyde-3-phosphate dehydrogenase, GAPDH) was calculated by using a fluorescence curve prepared from amplicons of serially diluted standard RNA. The relative points of MRD in bone marrow (BM) of 8 patients in the acute phase of the disease was from 0.85 to 3.0, whereas those of MRD in complete remission (CR) decreased to below 6.4 x 10(-3). This method was also applied to evaluate chimeric transcripts in peripheral blood (PB) samples. The values in patients with t(8;21) AML were from 0.97 to 2.0 in the acute phase, whereas those in CR showed less than 2.2 x 10(-4). There was 10(-5)-fold difference in AML1-ETO mRNA expression between PB samples in the acute phase and those in CR. The results suggest that we may easily monitor MRD in patients with t(8;21) AML through quantitative analysis of AML1-ETO transcripts in blood samples.

Chromosomes, Human, Pair 21↗
PubMed2000

Intrapulmonary concentrations of inflammatory cytokines in a mouse model of chronic respiratory infection caused by Pseudomonas aeruginosa.

We investigated the role of inflammatory cytokines in a mouse model of chronic Pseudomonas aeruginosa infection mimicking diffuse panbronchiolitis (DPB), and determined the effects of clarithromycin therapy on the production of these cytokines. The concentrations of IL-1beta, IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were measured serially in the lungs of mice with experimentally induced chronic respiratory P. aeruginosa infection until 60 days after inoculation. The concentrations of these cytokines during the course of the disease were significantly higher than baseline (before inoculation, P<0.01 for all cytokines). Clarithromycin significantly inhibited the production of IL-1beta and TNF-alpha in the lung (P<0.01). The same treatment also reduced the levels of other cytokines, albeit insignificantly. Treatment with anti-TNF-alpha antibody significantly reduced the number of pulmonary lymphocytes and concentration of IL-1beta in the lung (P<0.01), but did not change the number of viable bacteria. Our findings resemble those detected in bronchoalveolar lavage fluid of patients with DPB and indicate that inflammatory cytokines play an important role in chronic P. aeruginosa lung infection. Our results also show that macrolides modulated the production of these cytokines, ultimately reducing lymphocyte accumulation in the lung. Our data suggest that anti-TNF-alpha antibody might be a useful new strategy for the treatment of chronic respiratory P. aeruginosa infection.

Animals↗
PubMed2000

Larval-to-adult conversion of a myogenic system in the frog, Xenopus laevis, by larval-type myoblast-specific control of cell division, cell differentiation, and programmed cell death by triiodo-L-thyronine.

For the clarification of larval-to-adult muscle conversion, the authors established primary culture methods for adult- and larval-type myoblasts in the frog, Xenopus laevis, and examined the hormonal response in each case. The cell types were enzymatically dissociated from adult frog leg and tadpole tail muscles, respectively. The cells became attached to culture plates, proliferated, and fused with each other to form multinucleated myotubes within one week. Five significant differences between the two cell types were noted. (1) Adult cells showed greater proliferation activity than larval cells, the former increasing 5.5-fold over 6 days while the latter increase only 2.5-fold. (2) Differentiation (fusion) of larval type myoblasts started earlier. Cell fusion began on day 2 or 3 in larval cells and on day 4 in adult cells. (3) The metamorphic hormone, triiodo-L-thyronine (T3) decreased larval cell numbers to 56% of that of control-cultures on day 7 but had no effect on adult cell number. DNA synthetic activity (3H-thymidine incorporation) in larval cells decreased under T3 (10(-8) M) to 45% of the control level on day 7. (4) Differentiation of adult myoblasts into myotubes was promoted by T3, whereas that of larval cells diminished by half. (5) Myotube death was induced by T3 specifically in larval but not in adult cultures. In addition to the myotube death, double staining with TUNEL (in situ DNA nick end labeling) and anti-desmin antibody indicated that T3 induces myoblast (desmin+ cell) death specifically in larval but not in adult cells. It is thus evident that the conversion of a larval-type myogenic system during metamorphosis becomes possible through nearly totally specific control of cell division, cell differentiation, and programmed cell death at a precursor cell level by T3.

Animals↗
PubMed2000

Expression of osteopontin messenger RNA by macrophages in ovarian serous papillary cystadenocarcinoma: a possible association with calcification of psammoma bodies.

Calcified psammoma bodies often appear in human ovarian serous papillary cystadenocarcinoma. Osteocalcin (OC), osteonectin (ON) and osteopontin (OPN) are three members of non-collagenous bone-related proteins known to be related with mineralization of bone. To clarify possible involvement of these bone matrix proteins in the calcification of the psammoma bodies, the expression of OC, ON and OPN was analyzed by immunohistochemical and in situ hybridization studies using 15 surgical specimens. OPN protein was detected in the calcified area of the psammoma bodies which was positively stained by von Kóssa's staining, while OC and ON proteins were not. OPN protein was not detected in any cells in tissues, but OPN messenger ribonucleic acid (mRNA) was detected in CD68-positive macrophages, indicating that OPN was produced and promptly secreted by macrophages. These results suggest that OPN produced and promptly secreted by macrophages and subsequently translocated to psammoma bodies may be causally related with the calcium phosphate deposition in the psammoma bodies of the ovarian serous papillary cystadenocarcinomas.

Antigens, CD↗
PubMed2000

Expression of cytokeratin 1, 5, 14, 19 and transforming growth factors-beta1, beta2, beta3 in osteofibrous dysplasia and adamantinoma: A possible association of transforming growth factor-beta with basal cell phenotype promotion.

To elucidate the precise origin and characteristics of the epithelial components of osteofibrous dysplasia (OF) and adamantinoma (AD), the expression of transforming growth factor (TGF)-beta1, beta2 and beta3 and cytokeratin (CK) subtypes were studied in five cases of AD and 18 cases of OF by immunohistochemistry. CK1 was expressed in 10 out of 18 OF cases; CK5 was expressed in one OF case; CK14 was positively stained in 10 cases of OF; CK19 was positively stained in 16 OF cases; CK1 was expressed in three out of five AD cases; CK5 was expressed in one case of AD; CK14 was positively stained in four AD cases; and CK19 was positively stained in five AD cases. In OF, TGF-beta1, beta2 and beta3 were expressed in both fibroblasts and osteoblasts. In AD, TGF-beta1, beta2 and beta3 were expressed in both epithelial and fibrous components. These results suggest that epithelial components of AD and OF share epidermal characteristics, CK1, express basal cell phenotype and cytokeratins 5, 14 and 19. In addition to these epithelial characteristics, strong immunoreactivity for TGF-beta poses the possibility of TGF-beta promotion of basal cell phenotype expression for the epithelial components in OF and AD.

Adolescent↗
PubMed2000

Pleural amyloidosis in a patient with intractable pleural effusion and multiple myeloma.

Pleural involvement of systemic amyloidosis has been rarely reported. We report a case with multiple myeloma presenting an intractable right pleural effusion, in which pleural amyloidosis was diagnosed through pleural biopsy using a Cope needle. The diagnosis of pleural amyloidosis is important, because its refractory pleural effusion should be treated with pleurodesis. Since closed pleural biopsy using a Cope needle is much less invasive than thoracoscopy, the former should be attempted first whenever pleural amyloidosis is suspected.

Aged↗
PubMed2000

Easy aortic cannulation: a transxyphoid approach.

An easy aortic cannulation technique in minimally invasive pediatric cardiac surgery is described. We have developed a dilator which fits an aortic perfusion cannula. The aortic cannula over the dilator with a hole for passage of a guide wire is inserted into the ascending aorta by the Seldinger technique. Using this technique, the cannula never slips off, even at a slant angle to the aorta owing to the guidance of the guide wire. We recommend this safe and reliable technique for insertion of an aortic cannula into the ascending aorta in minimally invasive pediatric cardiac surgery.

Aorta↗
PubMed2000

Use of tactile stiffness to detect fatigue in the latissimus dorsi muscle.

In clinical settings, no method has been established to examine the fatigue of a latissimus dorsi muscle (LDM) preconditioned for cardiomyoplasty. We examined the feasibility of measuring muscle stiffness (tactile stiffness) to evaluate muscle fatigue in situ using our tactile sensor. We stimulated canine LDM with burst pacing and monitored both stiffness and tension to determine their relationship. In both dissected LDM and LDM in situ, the decrements of these parameters during burst pacing were compared between preconditioned and unconditioned LDM. In measurement in situ, the sensor probe was placed on the LDM through a small incision. Strong statistical correlation was shown between stiffness and tension (r = 0.935). In decrements of stiffness in situ, there were statistically significant differences between preconditioned and unconditioned LDM. Our tactile sensor system can provide an efficient method for evaluating fatigue of muscles in situ without measuring muscle tension.

Analysis of Variance↗
PubMed2000

Detailed deletion mapping of chromosome band 14q32 in human neuroblastoma defines a 1.1-Mb region of common allelic loss.

Neuroblastoma (NB) is a well-known malignant disease in infants, but its molecular mechanisms have not yet been fully elucidated. To investigate the genetic contribution of abnormalities on the long arm of chromosome 14 (14q) in NB, we analysed loss of heterozygosity (LOH) in 54 primary NB samples using 12 microsatellite markers on 14q32. Seventeen (31%) of 54 tumours showed LOH at one or more of the markers analysed, and the smallest common region of allelic loss was identified between D14S62 and D14S987. This region was estimated to be 1-cM long from the linkage map. Fluorescence in situ hybridization also confirmed the loss. There was no statistical correlation between LOH and any clinicopathologic features, including age, stage, amplification of MYCN and ploidy. We further constructed a contig spanning the lost region using bacterial artificial chromosome and estimated this region to be approximately 1.1-Mb by pulsed-field gel electrophoresis. Our results will contribute to cloning and characterizing the putative tumour-associated gene(s) in 14q32 in NB.

Alleles↗
PubMed2000

Combination therapy for chronic Pseudomonas aeruginosa respiratory infection associated with biofilm formation.

There had been no reports of investigations into biofilms in chronic respiratory infection in vivo. Recently, we established a new murine model of chronic respiratory infection with Pseudomonas aeruginosa. In the present study, we examined the bacteriological effect of combined clarithromycin and levofloxacin against chronic respiratory infection with P. aeruginosa. Scanning electron micrograph of the surface of the catheter intubated in mouse bronchus for 7 days demonstrated in vivo formation of a biofilm containing blood cells, complex fibrous structures and bacteria. Treatment with either clarithromycin alone or levofloxacin alone had no statistical effect on the number of viable bacteria in lung. The combined use of both drugs resulted in a significant decrease in the number of viable bacteria. The present experiment demonstrates that the newly established murine model was useful to investigate the treatment of biofilm-associated chronic respiratory infection with P. aeruginosa, and combination therapy with clarithromycin and levofloxacin was effective in biofilm-associated chronic respiratory infection.

Animals↗
PubMed2000

Expression and imprinting status of human PEG8/IGF2AS, a paternally expressed antisense transcript from the IGF2 locus, in Wilms' tumors.

A large imprinted gene cluster in human chromosome 11p15.5 has been implicated in Beckwith-Wiedemann syndrome and Wilms' tumor. We have identified a paternally expressed imprinted gene, PEG8/IGF2AS, in this locus. It is transcribed in the opposite direction to the IGF2 transcripts and some genomic regions are shared with the IGF2 gene, as in the case of the mouse imprinted Igf2as gene reported previously by T. Moore et al. As to the relationship between these genomic regions, the human and mouse genes are very similar but there is no homology in their middle parts. Interestingly, PEG8/IGF2AS and IGF2 were found to be overexpressed in Wilms' tumor samples, at levels over ten and a hundred times higher than that in normal kidney tissues neighboring the tumors, respectively. These findings indicate that PEG8/IGF2AS is a good marker of Wilms' tumor and also suggest the possibility of PEG8/IGF2AS being one of the candidate Wilms' tumor genes.

Amino Acid Sequence↗
PubMed2000

Genetic characterization of rbt mutants that enhance basal transcription from core promoters in Saccharomyces cerevisiae.

While this Saccharomyces cerevisiae SIN4 gene product is a component of a mediator complex associated with RNA polymerase II, various studies suggest the involvement of Sin4 in the alteration of higher-order chromatin structure. Our previous analysis of a sin4 mutant suggested that the mechanisms of transcriptional repression by Sin4 (mediator) and the Tup1-Ssn6 complex (general repressor) are different. To elucidate the way in which these two repression systems are interrelated, we isolated mutants that exhibit enhanced transcription of a reporter gene harboring the upstream activation sequence (UAS), but still are subject to Tup1-Ssn6-mediated repression. Besides sin4, rgr1, tup1, and ssn6 mutants, we also obtained new mutants that enhance basal transcription even from a core promoter without UAS. Such mutants, designated rbt for regulator of basal transcription, can be classified into at least six complementation groups, i.e., four single (rbt1 to rbt4) and two apparently double (rbt5 rbt6 and rbt7 rbt8) mutations. The phenotype of rbt mutants is dependent on the TATA box and not specific to the integration site or kind of core promoter. No significant difference in micrococcal nuclease (MNase) accessibility to the core promoter of test genes was observed between rbt mutants and the wild-type strain, indicating that the higher-order chromatin structure of the core promoter region is not significantly altered in these mutants. The rbt1 to rbt4 mutations are suppressed by the Dgal11 mutation as in the case of the sin4 mutation, but give rise to a different profile from the sin4 mutation with regard to the activity of some of the promoters. From these observations, we suggest that RBT gene product(s) could be novel mediators that act with or in close association with Sin4 but have a function distinct from that of Sin4. Moreover, the fact that rbt mutations nullify Tup1-Ssn6 general repressor-mediated repression is consistent with the idea that the mechanisms of Rbt (mediator)- and Tup1-Ssn6 (general repressor)-mediated repression are interconnected but substantially different.

Acid Phosphatase↗