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Biomedical subjects

K Kato

Publications and source records attributed to K Kato.

At least 253 records · Page 14Linked to original sources
PubMed2001

Immunoglobulin heavy chain gene analysis of ocular adnexal extranodal marginal zone B-cell lymphoma.

PURPOSE: To clarify the cellular origin of extranodal marginal-zone B-cell lymphoma (EZML) of the mucosa-associated lymphoid tissue (MALT) type in ocular adnexa, the somatic mutation was analyzed in the immunoglobulin heavy-chain variable region (VH) gene. METHODS: Eight cases of EZML in the orbit and four in the conjunctiva were studied. The VH genes were amplified by a seminested PCR and sequenced directly. These were compared with the closest published VH germline segments to determine the somatic mutation frequency. Intraclonal microheterogeneity, which was termed the ongoing mutation frequency in the current study, was estimated by counting the number of single nucleotide substitutions in individual clones and dividing by the total number of nucleotides analyzed. Nine cases of gastrointestinal EMZL were also examined for comparison. RESULTS: The somatic mutation frequency varied between 2.0% and 12.7%, with a mean value of 7.9%. Ten cases with intraclonal microheterogeneity showed between one and six further substitutions. The average of ongoing mutation frequency was 0.11%, with a range of 0% to 0.25%. In the gastrointestinal EMZLs, the average of somatic mutation frequency was 8.5% (1.5%-14.2%) and of ongoing mutation frequency was 0.51% (0.25%-0.75%). CONCLUSIONS: The average of ongoing mutation frequency in ocular adnexal EMZL was lower than that in gastrointestinal EMZL. Both ocular adnexal and gastrointestinal EMZLs are derived from postgerminal center memory B cells, but the low ongoing mutation frequencies of ocular adnexal EMZL may result from less antigen stimulation and follicular colonization in the orbit relative to gastrointestinal EMZL.

Adult↗
PubMed2001

17 beta-Hydroxysteroid dehydrogenase type 2 expression and enzyme activity in the human gastrointestinal tract.

The 17 beta-hydroxysteroid dehydrogenases (17 beta HSDs) play an important role in the regulation of intracellular levels of biologically active sex steroid hormones in various human tissues. To date, eight distinctive 17 beta HSD enzymes have been cloned and characterized in humans. Among these isoenzymes, 17 beta HSD type 2 (17 beta HSD2) catalyses the conversion of testosterone into androstenedione and/or oestradiol into oestrone in various tissues, and it has thus been suggested to be involved in the biological inactivation of these sex steroids. The human gastrointestinal tract and liver are considered as the principle sites of inactivation and metabolism of various forms of orally administered sex steroids. We therefore examined 17 beta HSD2 expression and activity in human adult non-pathological gastrointestinal tract in order to clarify further the biological significance of this enzyme. A total of 80 specimens (40 from males and 40 from females) of normal oesophageal, stomach, duodenal, ileal, colonic and rectal tissues were examined for immunohistochemistry. Altogether, 17 tissue specimens were used for enzyme assay, and eight for RNA analysis. 17 beta HSD2 activity was detected in the stomach, duodenum, ileum, colon and rectum. 17 beta HSD2 mRNA was most abundant in the small intestine. 17 beta HSD2 immunoreactivity was localized almost exclusively to the absorptive epithelium, which may be involved in the inactivation of excessive endogenous and exogenous active sex steroids. Results from the present study thus suggest that the human gastrointestinal tract is an important sex steroid metabolizing organ in humans.

17-Hydroxysteroid Dehydrogenases↗
PubMed2001

[Implementation and evaluation of public relations activity in a community health program].

OBJECTIVE: This study evaluated public relations activity in a community health program in order to develop effective strategies to attract the public attention for the program. METHODS: An intervention study was conducted on public relations for "Nutrition Seminar for Citizens," sponsored by the Health Department of Machida City, Tokyo, in October, 1999. One ward in the city was selected as an intervention area, and another ward which had similar demographic and geographic characteristics was chosen as a control area. Two target populations were defined; one was women in their 20s to 60s (#1) and the other was those who had previously never utilized community health programs sponsored by the city (#2). Handbills were used as the medium for public relations for the seminar. These announced the time, place and content of the nutrition seminar and were designed by authors with special attention to catchphrases, colors and fonts. Handbills were distributed in the intervention area through elementary schools, local voluntary organizations and local health volunteers. In addition, the authors directly handed them out to people in front of two supermarkets in the town. The sources of seminar information were requested from the participants of the Nutrition Seminar with a self-administered questionnaire. RESULTS: 1. The percentage of participants who received the seminar information from handbills was higher than that of those who used monthly newsletters from the city as a source of information. 2. The percentage of participants from the intervention area was higher than that from the control area. 3. Regarding target populations #1 and #2, there were no differences in participation rates between the intervention and control area. 4. Among the four distribution routes, the local voluntary organization route was the most effective for attracting participants. CONCLUSIONS: The results show that handbills can be an effective medium for pubic relations to increase the number of participants in community health programs. Also, local voluntary organizations can play a crucial role in information transfer in the community because of their high credibility. On the other hand, we could not reach specified target populations with the medium. Further surveys are needed to establish optimal media and routes to reach appropriate target populations in health programs.

Adult↗
PubMed2001

[The usefulness of two-step tuberculin skin testing in nosocomial infection cases].

The usefulness of the two-step tuberculin skin test in the preceding year for the contact investigation was reported, when a pulmonary tuberculosis patient was discovered in our hospital. Four persons showed stronger reaction than the results in two-step tuberculin skin test in the preceding year after nosocomial infection. One of them was diagnosed as pulmonary tuberculosis by chest radiograph, and antituberculosis chemotherapy was started. Other three started chemoprophylaxis. The chemoprophylaxis subjects might increase 4, if basic value of tuberculin reaction had not been available by two-step tuberculin skin test in the previous year. We could identify persons in whom tuberculin reaction became stronger by comparing the test results after exposure with the result of two-step tuberculin skin test in the preceding year. It is considered that two-step tuberculin skin test is very useful to efficiently execute the protective measure.

Adult↗
PubMed2001

[The effectiveness of steroid as adjunctive therapy in the management of two patients with febrile reaction due to antituberculous drugs].

Antituberculous treatment could be continued by using steroid as adjunctive therapy in two patients showing febrile reaction to antituberculous drugs in spite of desensitization therapy. Case 1 (39-year-old man) was admitted to our hospital with positive sputum-smear and bilateral cavitary tuberculosis (b II 2) on chest X-ray. He showed fever of 38-39 degrees C after 8 days of HREZ treatment. Desensitization therapy of RFP with the combined use of prednisolone was enforced, since the exothermic reaction continued in spite of stopping the 4 medicines, and the treatment became possible. Case 2 (40-year-old woman) was admitted with positive sputum-smear and bilateral cavitary tuberculosis (b II 2) on chest X-ray. The administration of drugs was stopped as temperature rose to 38-39 degrees C after 12 days of HREZ treatment. Though the DLST of INH was positive, the treatment with INH became possible by the combined use of PSL.

Adult↗
PubMed2001

[A patient with Moyamoya-like vessels after radiation therapy for a tumor in the basal ganglia].

A patient with Moyamoya-like vessels after radiation therapy for treatment of a tumor in the basal ganglia is reported. He was diagnosed as Down syndrome at birth. He had a tumor in the left basal ganglionic region at 12 years of the age. The tumor increased in size at age 14. He underwent cerebral angiography, which did not show a stenosis nor occlusion of the internal carotid artery, anterior cerebral artery, nor the middle cerebral artery. He received radiation therapy with a total dose of 56 Gy. He presented a dressing apraxia at age 19. MRI showed cerebral infarction in the left temporo-occipital region. Right internal carotid angiography revealed a severe stenosis of the internal carotid artery and anterior cerebral artery as well as a severe stenosis of the middle cerebral artery on the right side. Moyamoya-like vessels were seen in the basal ganglionic region. Left internal carotid angiography also showed a stenosis of the internal carotid artery and anterior cerebral artery as well as a severe stenosis of the middle cerebral artery on the left side. Moyamoya-like vessels were seen in the basal ganglionic region. Leptomeningeal anastomose and transdural anastomose were bilaterally seen. These arterial occlusion and stenotic phenomenon corresponded to a previous radiation field. These Moyamoya-like vessels with arterial stenosis and occlusion were thought to be due to radiation-induced vasculopathy, because a previous cerebral angiography showed a normal caliber of cerebral arteries. This patient showed that patients with radiation therapy in their early childhood should be carefully observed considering the possibility of this phenomenon.

Adult↗
PubMed2001

T-cell-conditioned medium efficiently induces the maturation and function of human dendritic cells.

We present evidence that T-cell-conditioned media (TCCM) can efficiently induce human immature dendritic cells (DC) to express high levels of immune accessory molecules commonly found on mature DC. TCCM prepared from cell-free supernatants of anti-CD3-activated T cells contained several soluble factors including CD40-ligand (sCD40L), TNF-alpha, and IFN-gamma. In contrast to moderate up-regulation of costimulatory molecules by the addition of individual cytokines or monocyte-conditioned medium, treatment of immature DC with TCCM induced a marked increase in the expression of costimulatory molecules in a dose-dependent manner. The ability of TCCM to induce such phenotypic changes could be abrogated by neutralizing antibodies specific for CD40L, TNF-alpha, and IFN-gamma, indicating that these factors present in TCCM are mainly implicated in the maturation of DC. Importantly, TCCM-treated DC can produce significantly higher levels of IL-12 and are highly effective stimulators in allogenenic and autologous mixed-lymphocyte reactions. Overall, these findings show that cultivation with TCCM is an efficient approach for the induction of mature DC that should be useful in eliciting antigen-specific immune responses against cancer and viruses.

Antigen Presentation↗
PubMed2001

Soluble CD154 in rheumatoid arthritis: elevated plasma levels in cases with vasculitis.

OBJECTIVE: To determine the levels of soluble CD154 (sCD154) in the plasma of patients with rheumatoid arthritis (RA) and rheumatoid vasculitis (RV). and to examine the relationship between the levels of sCD154 in plasma and the clinical variables. METHODS: Levels of sCD154 were quantified in 39 plasma samples from patients with RA, including 9 patients who were also diagnosed with RV, and compared with those of 20 healthy subjects. An ELISA was established and specificity of the ELISA was tested by control ELISA using isotype-matched IgG and preabsorption assay. The titers of IgM and IgG rheumatoid factor (IgM-RF, IgG-RF) for each patient were determined simultaneously, and values of other laboratory variables were also determined. RESULTS: Levels of sCD 154 in plasma were higher in patients with RA than in the healthy subjects (p < 0.02). Compared with RA patients without vasculitis, patients with RV had significantly higher levels of sCD154 in their plasma (p < 0.001). Control ELISA and absorption assay of sCD154 indicated that our ELISA system was capable of measuring plasma sCD154 in RA patients. Levels of sCD154 in RA plasma correlated significantly with both IgM-RF and IgG-RF titers (r = 0.64 and 0.61, respectively, both p < 0.001). The levels of sCD154 decreased after commencement of treatment for vasculitis in cases with RV. CONCLUSION: We identified the presence of sCD154 in RA plasma, with especially high levels in cases with vasculitis. Correlation between sCD154 and RF titers indicates the CD154-CD40 pathway is likely related to pathogenic RF production.

Adult↗
PubMed2001

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1998 and March 1999].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. This paper describes the results obtained in fiscal 1998 (from April 1998 to March 1999). The number of cases investigated as objectives was 225 for one year. A total of 429 strains (121 strains from primary infections and 308 strains from postoperative infections) were isolated from 183 cases (81.3% of total cases). In primary infections, the isolation rates of anaerobes and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes and Pseudomonas aeruginosa were higher than in primary infections. On the whole, among Gram-positive aerobes, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus with high frequency in isolation from postoperative infections. Among Gram-positive anaerobes, Peptostreptococcus spp. and Streptococcus spp. were predominantly isolated. Among Gram-negative aerobes, E. coli, P. aeruginosa, Klebsiella pneumoniae and Enterobacter cloacae were frequently isolated. Among Gram-negative anaerobes, Bacteroides fragilis group was the majority of isolates. In primary infections, the percentage of Gram-negative aerobes has gradually increased since fiscal 1995 or 1996 with these years as the turning point, while those of Gram-positive and Gram-negative anaerobes have gradually declined. In postoperative infections, the percentage of Gram-negative anaerobes has increased continuously since the mid-1980s. The percentage of MRSA among S. aureus rose to 89.7%, which was the highest level since the beginning of this study. The susceptibilities of B. fragilis, which did not show apparent changes, were recognized to have decreased against cephems in fiscal 1998. Among other bacteria in B. fragilis group, development of resistance to cephems has continued on a long-term basis since the mid-1980s. E. coli and K. pneuminiae have obviously not changed in susceptibilities, however, the susceptibilities of isolated strains in fiscal 1998 against high-generation cephems, oxacephems and monobactams have declined. We found neither vancomycin-resistant nor teicoplanin-resistant strains of S. aureus and Enterococcus spp.

Anti-Bacterial Agents↗
PubMed2001

[A case of posterior mediastinal ganglioneuroma with fat tissue].

We present a rare case of posterior mediastinal ganglioneuroma with fat tissue. A 50-year-old man visited our Department of Internal Medicine because of hypertension and fatty liver. On screening with abdominal CT a soft tissue tumor was found in the posterior mediastinum. CT and MRI revealed that the tumor appeared to have an abundant fatty component. To obtain a definitive diagnosis, the tumor was resected thoracoscopically. The histological diagnosis was ganglioneuroma. A ganglioneuroma containing a fat component has rarely been reported after cross-sectional imaging. We infer that the tumor may have resulted from spontaneous regression, with subsequent infiltration of adipose tissue from the posterior mediastinum.

Adipose Tissue↗
PubMed2001

Longitudinal measurement of bone mineral density at the radius in hemodialysis patients using dual-energy X-ray absorptiometry.

The object of our study was to document the changes in bone mineral density (BMD) at the (1/3) distal radius in patients undergoing maintenance hemodialysis (HD). Forty nine male and 24 female patients were enrolled in this study. The mean age was 55.9-/+13.1 (mean -/+ SD) years, and the duration of HD was 89.2 -/+ 81.0 months at the beginning of the investigation. BMD was measured by dual-energy X-ray absorptiometry at 1-year intervals for a period in excess of 3 years. No significant relationship was observed between BMD and age in both sexes. In male patients, BMD was positively correlated with body mass index (BMI) (r=0.47, p<0.01) and negatively with the duration of HD (r=0.61, p<0.01). In contrast, BMD was not correlated with either BMI or with the duration of HD in female patients. Eleven of the 14 patients on HD for more than 15 years showed marked bone loss (male; 0.460, female; 0.394g/cm(2)), although they were relatively young (mean age: 43.4 years). Prolonged HD could be one of the risk factors responsible for bone loss.

Journal Article↗
PubMed2000

Gene expression profiling of mouse postnatal cerebellar development.

Expression patterns of 1,869 genes were determined using adapter-tagged competitive PCR (ATAC-PCR) at 6 time points during mouse postnatal cerebellar development. The expression patterns were classified into 12 clusters that were further assembled into 3 groups by hierarchical cluster analysis. Among the 1,869 genes, 1,053 known genes were assigned to 90 functional categories. Statistically significant correlation between the clusters or groups of gene expression and the functional categories was ascertained. Genes involved in oncogenesis or protein synthesis were highly expressed during the earlier stages of development. Those responsible for brain functions such as neurotransmitter receptor and synapse components were more active during the later stages of development. Many other genes also showed expression patterns in accordance with literature information. The gene expression patterns and the inferred functions were in good agreement with anatomical as well as physiological observations made during the developmental process.

Animals↗
PubMed2000

Determination of pibutidine metabolites in human plasma by LC-MS/MS.

A novel metabolite-screening procedure for pibutidine. an H2-receptor antagonist, which uses high-performance liquid chromatography/tandem mass spectrometry (LC-MS/MS), demonstrated the presence of pibutidine and its four metabolites in plasma from volunteers who received a single dose of pibutidine hydrochloride. In order to quantitatively examine the metabolism of pibutidine, an assay based on LC-MS/MS was subsequently developed for the simultaneous determination of its metabolites in human plasma. Target analytes consisted of M-5, M-7 and M-8, which were prominently detected by the screening procedure, and M-9, which has pharmacological activity as an H2-receptor antagonist. Metabolites and their deuterated internal standards were extracted from human plasma using an Oasis HLB extraction cartridge, and chromatographed on a Monitor C18M column. No isotope effects on chromatographic retention time were observed for any deuterated compounds, which were ionized using an electrospray ionization (ESI)- interface and detected by MS/MS in the selected reaction-monitoring (SRM) mode simultaneously with the corresponding metabolites. The assay was validated over the concentration range of 0.1 to 25.6 ng ml(-1) and used to determine the plasma levels of metabolites in volunteers following oral administration of a 20-mg dose of pibutidine hydrochloride.

Area Under Curve↗
PubMed2000

Predictors of disease course in patients with acute myocarditis.

BACKGROUND: Clinical manifestations of acute myocarditis, with distinct onset, vary from asymptomatic to fatal. The predictors of the course of the disease in patients with acute myocarditis at initial presentation have not yet been established. In this study, we examined the predictive values of various parameters in the disease course of patients with myocarditis. METHODS AND RESULTS: Twenty-one consecutive patients who had been diagnosed as having acute myocarditis by histological examinations were analyzed. The patients with myocarditis were divided into the survival group (n=13) and the fatal group (n=8). We examined the parameters of the clinical state, hemodynamic variables, required therapies, biochemical laboratory data, and cytokines. The control groups were composed of 23 patients with old myocardial infarction and 20 healthy volunteers. The fatal group had lower blood pressure and higher pulmonary capillary wedge pressure compared with those values in the survival group. Mechanical ventilation support was more frequently required in the fatal group. Serum levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were significantly higher in the myocarditis group than in the 2 control groups. Furthermore, levels were significantly higher in the fatal group than in the survival group for sFas (13.93+/-4.77 versus 3.77+/-0.52 ng/mL, respectively; P:<0.001) and sFasL (611.4+/-127.7 versus 269.5+/-37.3 pg/mL, respectively; P:<0.05). Other clinical states, hemodynamic variables, required therapies, and biochemical laboratory parameters were not different between the 2 groups. CONCLUSIONS: Elevation of sFas and sFasL levels at initial presentation appear to be a good serological marker to predict the prognosis of acute myocarditis.

Acute Disease↗
PubMed2000

Microarray hybridization with fractionated cDNA: enhanced identification of differentially expressed genes.

Molecular indexing is a technique to select a subpopulation of cDNA by ligation of adapters to cDNA fragments digested by a class IIS restriction enzyme(s). By this technique, 3' end cDNA fragments are divided into 16 fractions by selective ligation of adapters and subsequent PCR amplification. Each fraction is used as a hybridization target for microarray hybridization. This fractionated target has a relatively lower nucleic acid complexity, including more fractions for rare transcripts, and is useful for their detection. In an experiment with mouse cerebellum and cerebrum RNA, analysis of a subset of candidate genes indicated that 10 times more differentially expressed genes were detected by this method than by the conventional method using the unfractionated target.

Animals↗
PubMed2000

Calcium stores regulate the polarity and input specificity of synaptic modification.

Activity-induced synaptic modification is essential for the development and plasticity of the nervous system. Repetitive correlated activation of pre- and postsynaptic neurons can induce persistent enhancement or decrement of synaptic efficacy, commonly referred to as long-term potentiation or depression (LTP or LTD). An important unresolved issue is whether and to what extent LTP and LTD are restricted to the activated synapses. Here we show that, in the CA1 region of the hippocampus, reduction of postsynaptic calcium influx by partial blockade of NMDA (N-methyl-D-aspartate) receptors results in a conversion of LTP to LTD and a loss of input specificity normally associated with LTP, with LTD appearing at heterosynaptic inputs. The induction of LTD at homo- and heterosynaptic sites requires functional ryanodine receptors and inositol triphosphate (InsP3) receptors, respectively. Functional blockade or genetic deletion of type 1 InsP3 receptors led to a conversion of LTD to LTP and elimination of heterosynaptic LTD, whereas blocking ryanodine receptors eliminated only homosynaptic LTD. Thus, postsynaptic Ca2+, deriving from Ca2+ influx and differential release of Ca2+ from internal stores through ryanodine and InsP3 receptors, regulates both the polarity and input specificity of activity-induced synaptic modification.

Animals↗