Search PubMed⌕ Search

Biomedical subjects

M Kaku

Publications and source records attributed to M Kaku.

At least 37 records · Page 2Linked to original sources
PubMed2001

Quantitative determination of gelatinase activity among enterococci.

Gelatinase, hemolysin and aggregation substance have all been reported to be virulence factors of enterococci. In this study, gelatinase production was investigated in isolates of Enterococcus faecalis (n=93), E. faecium (n=49) and E. avium (n=36) recovered from hospitalized patients. Gelatinase was detected in 45% of E. faecalis isolates, but could not be detected in E. faecium and E. avium. Gelatinase activity was then measured by radial diffusion for the 42 gelatinase-positive E. faecalis isolates. To convert gelatinase activity into proteinase K activity, a standard curve was produced by placing different concentrations of proteinase K into wells in the gelatine plate. Gelatinase activity per E. faecalis colony ranged from 2.6 x 10(-7) to 2.2 x 10(-5) microg/ml, proportionate to the activity of proteinase K. An approximately 84-fold difference in gelatinase concentration was observed between the colony producing the highest amount and that producing the lowest amount. This method may be useful for determining the virulence of given isolates in relation to gelatinase production as it is quick, easy and inexpensive to perform.

Adult↗
PubMed2001

Comparison of no airway device, the Guedel-type airway and the Cuffed Oropharyngeal Airway with mask ventilation during manual in-line stabilization.

STUDY OBJECTIVE: To compare two different types of oropharyngeal airway: the Guedel-type oral airway and the Cuffed Oropharyngeal Airway (COPA), with respect to the effectiveness of positive-pressure ventilation (PPV) through a face mask in patients with in-line stabilization of the head and neck. DESIGN: Prospective, randomized, crossover study. SETTING: University hospital. PATIENTS: 30 ASA physical status I and II patients undergoing elective surgery. INTERVENTIONS: General anesthesia was induced with propofol and muscle relaxation was produced with vecuronium. In a random sequence, no airway device, the Guedel-type airway, and the COPA were used in each patient while applying a face mask and lifting the jaw forward. MEASUREMENTS AND MAIN RESULTS: Tidal volumes were measured during PPV in each option. The position of the distal tip of each airway was assessed using a fiberscope, and the resulting views were graded and compared. When the Guedel-type airway was used, tidal volumes (V(T)s; means +/- SD) were significantly greater (12.3 +/- 4.5 mL/kg) than those with no airway device (8.5 +/- 4.5 mL/kg) (p < 0.001). When the COPA was used, V(T)s (14.6 +/- 4.4 mL/kg) were significantly greater than those with the Guedel-type airway (p < 0.05). The grade of the fiberscopic view through the distal tip was significantly better with the COPA than with the Guedel-type airway (p < 0.05). CONCLUSIONS: Although clinical differences often appear trivial, the COPA is more effective on mask ventilation than the Guedel-type airway when used in patients with manual in-line stabilization.

Adult↗
PubMed2001

Breadth of the mandibular condyle affected by disturbances of the sex hormones in ovariectomized and orchiectomized mice.

It is well known that the size of the condyle is different between males and females in humans. It has also been documented that ovariectomy (OVX) and orchiectomy (ORX) influence the remodeling of the condylar head in experimental animals. However, influences of sex hormones on the condyle in terms of its breadth have not been examined. With these considerations, this study was designed to examine the breadth of the mandibular condyle in OVX and ORX mice by histomorphometry 8 weeks after surgery. In the OVX mice, the condylar breadth was significantly larger than in the controls, while no significant differences in the breadth were found between the ORX mice and the controls. The thickness of the condylar cartilage layers exhibited similar findings to the breadth of the condyle. On the contrary, the trabecular bone volume was significantly smaller in the OVX and ORX mice than in the corresponding controls, and the difference was more substantial in female mice than in the males. These findings emphasize that a reduction of sex hormone levels, induced by OVX and ORX, significantly influences condylar morphogenesis.

Journal Article↗
PubMed2001

Decreased expression of transcription factor GATA-2 in haematopoietic stem cells in patients with aplastic anaemia.

Aplastic anaemia is characterized by reduced haematopoiesis resulting in pancytopenia. It has been speculated that there is an injury in haematopoietic stem cells in the bone marrow; however, the precise nature of the injury has not been elucidated. In this study, the levels of expression of mRNAs for three transcription factors, GATA-2, SCL and AML1, which function in the early stages of haematopoiesis, were examined by quantitative polymerase chain reaction in patients with aplastic anaemia, idiopathic thrombocytopenic purpura (ITP) and normal subjects. Among these factors, expression of GATA-2 mRNA in purified CD34-positive cells was markedly decreased in aplastic anaemia compared with that in ITP and in normal subjects. The expression levels of SCL and AML1 mRNA in CD34-positive cells in aplastic anaemia were not different from those in normal subjects. When the expression of GATA-2 protein in CD34-positive cells was examined by immunocytochemical analysis, the percentage of GATA-2-positive cells in aplastic anaemia was lower than that in normal subjects. These findings strongly suggest that there is an aberrant expression of transcription factors in stem cells in aplastic anaemia, which may be responsible for the development of the disease.

Anemia, Aplastic↗
PubMed2001

Quantitative evaluation of cytomegalovirus DNA in infantile hepatitis.

We used a PCR method to develop a diagnostic assay for the detection of cytomegalovirus (CMV) DNA in infantile hepatitis, which has been suggested to be associated with CMV infection. CMV DNA was detected in 25 (58.1%) of 43 patients with elevated serum alanine aminotransferase (ALT) levels but no jaundice, and no hepatitis B or C as assessed by conventional PCR. None of the samples from 97 healthy infants tested positive for CMV DNA. We assayed CMV DNA quantitatively in blood using a real-time PCR system that allowed reproducible detection of at least 10 copies of CMV DNA. When 1 microg of DNA from each blood sample was used in this system, a good correlation was obtained between the calculated and measured copy numbers of CMV DNA. This system detected CMV DNA in 29 patients (67.4%) with liver dysfunction. Serial studies in patients with liver dysfunction revealed that CMV DNA copy number decreased, ultimately to below 10, as the ALT levels normalized. In contrast, no CMV DNA copies were detectable by the real-time system in any of the samples from control subjects. These results highlight the usefulness of detecting CMV DNA in the diagnosis of infantile hepatitis and indicate that the real-time quantitative PCR assay may be a valuable tool for monitoring CMV-associated infantile hepatitis.

Alanine Transaminase↗
PubMed2001

Measurement of tumor necrosis factor-alpha messenger RNA in synovial fibroblasts by real-time quantitative reverse transcriptase-polymerase chain reaction.

We applied a real-time quantitative assay to determine the expression of tumor necrosis factor-alpha (TNF-alpha) messenger RNA (mRNA) in tissue samples. This method is based on the real-time monitoring of reverse transcriptase-polymerase chain reaction (RT-PCR) with a dual-fluorescence-labeled probe and a sequence detector. A linear correlation existed between assay measurements and input target (r = 0.999). TNF-alpha mRNA was detected in the synovial cells of patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and also in the U937, THP1, and HL60 cell lines. Stimulation with interleukin-1alpha (IL-1alpha) caused an immediate increase in the intracellular level of TNF-alpha mRNA. In particular, the relative copy number of TNF-alpha mRNA increased dramatically from 15 to 3554 in synovial cells from RA patients. This method is simple, accurate, and sensitive for the quantitative detection of TNF-alpha mRNA. The real-time quantitative RT-PCR assay may be valuable for measuring TNF-alpha mRNA expression in clinical samples.

Arthritis, Rheumatoid↗
PubMed2001

Childhood T-cell acute lymphoblastic leukemia with four distinct immunophenotypes representing different stages of T-cell development.

The authors report on a 14-year-old boy who developed T-cell acute lymphoblastic leukemia (FAB:L1) displaying 4 immunophenotypically distinct leukemic cell populations by 3-color immunofluorescence staining. Cytogenetic analysis at diagnosis showed 46,XY,add(4)(p16)[12]/46,XY[2]. A single rearrangement of the T-cell antigen receptor beta- and gamma-chain genes in these cells indicated monoclonality of the leukemic cells. These findings suggest that leukemic blast cells of monoclonal origin in this case were divided into 4 immunophenotypic populations, representing various stages of differentiation.

Adolescent↗
PubMed2001

Increased sensitivity to cytosine arabinoside in human leukemia by c-raf-1 antisense oligonucleotides.

c-raf-1, a cytoplasmic serine/threonine protein kinase, plays an important role in mitogen- and damage-responsive cellular signal transduction pathways. Expression of c-raf-1 modifies cell growth, proliferation and survival. Although expression of c-raf-1 has been studied in several tumors, the role of c-raf-1 in leukemia is so far unclear. We examined the expression of c-raf-1 in the human leukemia cell lines U937 and K562, and in a cytosine arabinoside (Ara-C)-resistant cell line (K562AC) derived from K562. Expression of c-raf-1 was increased in U937 and in Ara-C-resistant K562AC cells compared with the parental cells. We then investigated whether inhibition of c-raf-1 expression by antisense oligonucleotides increases the sensitivity to Ara-C in U937 and K562AC cells. Antisense oligonucleotides for c-raf-1 inhibited expression of c-raf-1 mRNA, but did not affect cell growth and increased sensitivity to Ara-C but not to other drugs such as adriamycin, VP-16 or vincristine. These results suggest that c-raf-1 is one of the factors involved in Ara-C resistance in leukemia and lend weight to the case for development of anti-cancer therapeutics involving oncogene-targeted antisense oligonucleotides.

Antimetabolites, Antineoplastic↗
PubMed2001

Modification of the sensitivity to cisplatin with c-myc over-expression or down-regulation in colon cancer cells.

Human colon cancer SW480 cells express the c-myc gene. On the other hand, SW480DDP cell lines resistant to cisplatin exhibited decreased c-myc gene expression, but their cell growth rates remained similar to those of their parental cells. Antisense oligonucleotides to c-myc inhibited c-myc expression and induced increased resistance to cisplatin in SW480 cells. In contrast, SW480DDP cells showed increased c-myc expression and reversed sensitivity to cisplatin when these cells were transfected with c-myc cDNA from the pLNCX plasmid. Moreover, SW480DDP cells transfected with c-myc cDNA induced apoptosis when exposed to cisplatin, but not SW480 cells transfected with an antisense sequence for c-myc. Transfection either with a c-myc antisense sequence or c-myc cDNA to these cells did not change their growth rates. Thus enforced expression of c-myc in SW480 and SW620 lines sensitizes cells to cisplatin-induced apoptosis, whereas the down-regulation of c-myc in SW480DDP and SW620DDP increases cisplatin resistance when using antisense strategy.

Adenocarcinoma↗
PubMed2001

Relatedness between the coagulase gene 3'-end region and coagulase serotypes among Staphylococcus aureus strains.

The 3'-end region of the coagulase gene from 22 strains of Staphylococcus aureus including 10 standard serotype strains was sequenced, and five subgroups with 4-8 tandem repeating units were distinguished among the tested strains. Phylogenetic analysis of the 3'-end region of the coagulase gene indicated that strains belonging to the same serotype were clustered in the same branch. A phylogenetic tree of the deduced amino acid sequences revealed that the C-terminal region might not be responsible for the epitope of the coagulase protein.

Bacteriological Techniques↗
PubMed2001

[The characterization of Vibrio cholerae non-O1 strain causing perforative pan-peritonitis].

We report a case of a 53-year-old male with Vibrio cholerae non-O1 (serotype O19) infection, resulting in perforative pan-peritonitis. The patient had a history of gastric cancer and a gastrectomy was performed one year prior. The patient had previously been admitted with nausea and vomiting and was diagnosed with a sub-ileus condition. He was provisionally discharged when his condition improved and during that period he ate raw fish caught locally in Nagasaki Prefecture, and several hours later he experienced a sudden onset of severe abdominal pain and nausea and on diagnosis of pan-peritonitis an emergency resection of the transverse colon was performed. We subsequently isolated Vibrio cholerae non-O1 from the patient's peritoneal fluid and stool. He died of multiple organ failure three weeks later despite intensive chemotherapeutic care and treatment for shock and disseminated intravascular coagulation. The strain of Vibrio cholerae non-O1 isolated was non-toxigenic but hemolytic with hyper-producing of metalloprotease.

Colectomy↗
PubMed2001

Effects of vascular endothelial growth factor on osteoclast induction during tooth movement in mice.

UNLABELLED: For orthodontic tooth movement, remodeling of the alveolar bone is maintained by a repeated process of bone resorption and new bone formation, controlled, respectively, by osteoclasts and osteoblasts. Recently, we have found that recombinant human vascular endothelial growth factor (rhVEGF) acts as a macrophage colony-stimulating factor in osteoclast induction in osteopetrotic (op/op) mice. The purpose of this study was to investigate whether rhVEGF stimulates osteoclast differentiation during experimental tooth movement. Purified rhVEGF was injected once into the buccal gingival groove around the incisors. An experimental appliance with a helical loop was bonded onto the upper incisors, and an initial force of 1.0 g was applied for three days. The number of osteoclasts appearing in the periodontal ligament space on the pressure side of the alveolar bone was increased markedly. These results suggest that local administration of rhVEGF enhances the number of osteoclasts, and may increase the rate of orthodontic tooth movement. ABBREVIATIONS: recombinant human vascular endothelial growth factor (rhVEGF), macrophage colony-stimulating factor (M-CSF), osteopetrotic mice (op/op mice),fms-like tyrosine kinase (Flt-1), periodontal ligament (PDL), phosphate-buffered saline (PBS), tartrate-resistant acid phosphatase (TRAP), and analysis of variance (ANOVA).

Acid Phosphatase↗
PubMed2001

[A case of Miller-Dieker syndrome associated with satellite on chromosome 17p].

In this report, we describe a one-year-old girl of the Miller-Dieker syndrome(MDS) with lissencephaly, seizures, microcephaly and mental disorders. Cytogenetic studies of this patient confirmed the presence of a 46,XX, 17ps+ chromosome karyotype, but it could not find the microdeletion of 17p13.3. Fluorescence in situ hybridization(FISH) studies confirmed a terminal deletion in the patient using the LIS1 gene probe which mapped to 17p13.3. Further it was also found the satellite on 17p13(17ps) in the patient who was rare associated with MDS. These findings suggest that FISH analysis may be useful method to detect microdeletion of LIS1 gene as 17-specific probe in the investigation of MDS patients.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2001

[Laboratory system for networks in infection control].

The goals of a surveillance for nosocomial infections are to observe the magnitude and characteristics of the infections, and to plan and evaluate policies and guidelines of infection control. In clinical laboratory, although it is most important to detect their causative pathogens, further to provide the surveillance study as a multicenter. Actually, we have just started an infection control room in our hospital. Thus this room may present various informations about infection and contribute to the networks with the area community.

Cross Infection↗
PubMed2001

[A case of 9p-syndrome identified chromosome 20 on chromosome 9p by M-FISH].

In this report, we describe one-year-old girl diagnosed with 9p-syndrome. Cytogenetic studies of this patient confirmed a karyotype of 46,XX,add(9) (p24) chromosome, but could not find the additional fragment on 9p22 in one allele. Fluorescence in situ hybridization (FISH) studies could not confirm the fragment in the patient using the LIS1 gene probe which mapped to 9p22. The more recently developed M-FISH method clearly showed that the additional fragment was 20p in this patient. These findings suggest that M-FISH analysis may be a useful method for identifying unknown additional and rearranged chromosomes.

Abnormalities, Multiple↗
PubMed2000

Detection of mutations in adenine phosphoribosyltransferase (APRT) deficiency using the LightCycler system.

We have applied an established technique, the polymerase chain reaction (PCR) with LightCycler technology, to a single disease with well-defined mutations. This assay produces results within only 30 min by combining PCR and fluorescence detection in one tube without electrophoretic band detection. In this study, we found 2,8-dihydroxyadenine (DHA) lithiasis in Japanese patients who were heterozygous for Japanese-type (type II) adenine phosphoribosyltransferase (APRT) deficiency (APRT*J). These patients, from a family with 2,8-DHA lithiasis, had a heterozygous mutation in the J region of the APRT gene. We demonstrated that the present system, using LightCycler technology, was simple, rapid, and reliable for detecting known mutations, and capable of identifying heterozygous and homozygous mutations in this family with APRT deficiency.

Adenine↗