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Biomedical subjects

Mikihiko Kawano

Publications and source records attributed to Mikihiko Kawano.

12 recordsLinked to original sources

Serum ghrelin and carotid atherosclerosis in older Japanese people with metabolic syndrome.

Ghrelin may play a role in the development of atherosclerosis. However, the effect of serum ghrelin on carotid intima-media thickness (cIMT) (well-established as a surrogate marker to atherosclerosis) in metabolic syndrome (MS), particularly among relatively older subjects, has still not been thoroughly investigated. A total of 101 subjects >60 years of age (mean age, 72.3 years) with MS were enrolled in the study to investigate the relationship between serum total ghrelin and B-mode ultrasonographic cIMT levels. There were significantly positive correlations between cIMT and both age and systolic BP, but cIMT was significantly inversely correlated to ghrelin levels. In the multiple regression analysis for cIMT adjusted by other measured parameters, ghrelin was a significant and independent factor along with age and systolic BP. These findings suggest that decreased ghrelin levels may be related to carotid atherosclerosis among older subjects with MS.

Aged↗

[Evaluation of samples that indicated the difference of immunoglobulin values between different assays].

Since the immunoglobulin levels of survey samples for the survey of Japanese Association of Medical Tech7ologists in 2003, especially the IgA and IgM, became different by the immunological methods (LAIA [latex agglutination immunoassay] and TIA [turbidimetric immunoassay]), the cause of difference was investigated. From the results of gel filtration and immunoblotting analysis, it was suggested that profiles of the reaction of purified IgA and IgM polymers in survey samples were different on each method. In the case of M protein, also, there were higher levels of IgM and IgA type M protein by TIA and SRID methods than other methods even though the precipitation curve was obscure. Similarly, several samples from patients with M protein demonstrated higher values by SRID method than that of other methods. When these samples were analyzed by gel filtration and immunoblotting, they did not indicate the presence of the polymeric IgM. It will be suggested that non-specific reactions on TIA (weak reaction) and SRID (unusual precipitin line) methods were present. Furthermore, in a case of IgM type M protein, IgM level was twice higher by LAIA than that by TIA. However, it did not indicate any polymer or fragment of IgM by gel filtration and immunoblotting. Accordingly, it was assumed that the difference in measured values between the methods was attributable to the difference of the reaction to the samples.

Glycoproteins↗

Involvement of the tumor necrosis factor (TNF)/TNF receptor system in leukemic cell apoptosis induced by histone deacetylase inhibitor depsipeptide (FK228).

Inhibition of histone deacetylase (HDAC) is a novel strategy for the treatment of leukemias via restoration of aberrantly silenced genes. In this study, we conducted a detailed analysis of anti-leukemic effects of an HDAC inhibitor (HDI), depsipeptide (FK228), using myeloid leukemia cell lines HL-60 and K562. DNA chip analysis revealed upregulation of TNF-alpha mRNA and a number of molecules involved in TNF-signaling such as TRAF-6, caspases-10, and -7 in depsipeptide-treated HL-60 cells, which prompted us to examine the involvement of the TNF/TNF receptor system in the anti-leukemic effects of the drug. Upregulation of TNF-alpha was induced by depsipeptide in HL-60 and K562 cells, which expressed type I TNF receptors (TNF-RI). Depsipeptide activated caspases-8 and -10, which in turn cleave caspases-3 and -7, leading to apoptotic cell death in both cell lines. Anti-TNF-alpha neutralizing antibody and short interfering RNA (siRNA) against TNF-RI alleviated the activation of the caspase cascade and the induction of apoptosis, indicating the presence of an autocrine loop. Finally, we demonstrated that the enhanced production of TNF-alpha by depsipeptide was due to transcriptional activation of the TNF-alpha gene through hyperacetylation of histones H3 and H4 in its promoter region (-208 to +35). These results suggest that autocrine production of TNF-alpha plays a role in the cytotoxicity of depsipeptide against a subset of leukemias.

Acetylation↗

Self-assembly of HDL network on mica.

The structure of high-density lipoprotein (HDL) is a subject that continues to attract interest. The goal of this study is to observe the self-assembly construction of HDL on mica using atomic force microscopy (AFM). On mica, HDL was observed to form a honeycomb-like network formation. The narrowest part of the HDL wire was approximately 5.6 nm. HDL can be used in the microcircuitry of electronic devices and is of great interest in the field of nanotechnology.

Aluminum Silicates↗

Tamoxifen might influence the affinity of LPL for heparin-sepharose.

BACKGROUND: We previously reported that the tamoxifen treatment caused a decrease in lipoprotein lipase (LPL) activity and an increase in LPL mass. We hypothesized that tamoxifen may increase the quantity of inactive LPL. METHODS: Lipoprotein lipase in post-heparin plasma usually exists in both monomeric and dimeric forms, which may be separated on a heparin-Sepharose column with different salt concentrations. Lipoprotein lipase in post-heparin plasma from postmenopausal patients with hypertriglyceridemia treated with or without tamoxifen was incubated with or without 4-hydroxy-tamoxifen (4-OHT), the monomers and dimers were separated on a heparin-Sepharose column and their masses were measured. RESULTS: The masses of total LPL and dimeric LPL of tamoxifen-treated patients were significantly higher than those of control subjects. Monomeric LPL of tamoxifen-treated patients passed more slowly through the heparin-Sepharose column compared with that of control subjects. The ratio of monomeric LPL to dimeric LPL of tamoxifen-treated patients was 0.61, significantly lower than that of control subjects, which was 1.45 (p<0.01). In addition, monomeric LPL incubated with 4-OHT passed more slowly through the heparin-Sepharose column compared with that incubated without 4-OHT. CONCLUSION: Tamoxifen influences the affinity of LPL for heparin.

Breast Neoplasms↗

[Laboratory examinations performed in rural practice].

Graduates from Jichi Medical School are obligated to work at rural clinics or hospitals, where most of them are the only medical doctor in the house. To understand how these graduates actually use laboratory examinations, what examinations they found most important in their practice, and when they were confident of their laboratory techniques, we designed a questionnaire to address these questions. Many respondents reported that their institutions had electrocardiographs, abdominal and/or cardiac ultrasonographs, urinalysis test paper, and portable blood glucose meters, and more than half of them reported having used these instruments without assistance in emergency situations. Moreover, a majority of the respondents said that they considered it important that a physician is able to use these instruments without the help of other staff members. Proficiency in many laboratory techniques was obtained and physicians were confident during their first postgraduate clinical practice. These responses clearly show the importance and usefulness of covering examination techniques and the principles of laboratory medicine in medical education and the first postgraduate clinical practice.

Clinical Competence↗

Marked removal of bezafibrate-induced high-density lipoprotein-cholesterol by low-density lipoprotein apheresis.

BACKGROUND: A case of marked reduction of the bezafibrate-induced increase of high-density lipoprotein (HDL)-cholesterol by low-density lipoprotein apheresis (LDL-apheresis) has not been previously reported. METHODS: A 68-year-old Japanese man with arteriosclerosis obliterans (ASO), diabetes mellitus, and hyperlipidemia underwent LDL-apheresis, followed by the concomitant bezafibrate administration. Plasma lipids of pre- and post-LDL-apheresis were measured and apolipoprotein E (apoE) localization of the pre- and post-LDL-apheresis was detected by agarose gel electrophoresis. RESULTS: Plasma concentrations of the total cholesterol, LDL-cholesterol, triglyceride, and HDL-cholesterol of pre-LDL-apheresis were 4.78 +/- 0.36, 2.74 +/- 0.24, 2.44 +/- 0.52, and 0.92 +/- 0.10 mmol/l, respectively; those of the post-LDL-apheresis were 1.94 +/- 0.31, 0.72 +/- 0.13, 0.81 +/- 0.38, and 0.86 +/- 0.11 mmol/l, respectively. LDL-apheresis reduced HDL-cholesterol by 6.4% (p=0.346). During the bezafibrate administration, plasma concentrations of the above of pre-LDL-apheresis were 5.24 +/- 0.34, 3.28 +/- 0.22, 1.26 +/- 0.25, and 1.39 +/- 0.21 mmol/l, respectively; those of the post-LDL-apheresis were 2.25 +/- 0.44, 0.80 +/- 0.12, 0.58 +/- 0.19, and 1.18 +/- 0.16 mmol/l, respectively. LDL-apheresis reduced HDL-cholesterol by 15.2% (p<0.01). Plasma apolipoprotein E detected between the prebeta- and alpha-mobility was markedly lower after the LDL-apheresis in the agarose gel electrophoresis. CONCLUSIONS: The removal of the bezafibrate induced an increase of the HDL-cholesterol by LDL-apheresis.

Aged↗

[Hyperlipidemia in the elderly].

Many studies show hypercholesterolemia is an even stronger risk factor for coronary heart disease(CHD) in the elderly, and most studies evaluated ischemic strokes separately show a positive association with cholesterol levels. Large prevention studies show HMG-CoA reductase inhibitors significantly decreased major coronary events in the elderly similar to that observed in the younger people, and were also effective in preventing ischemic stroke. For primary prevention, therapeutic life-style change is the first line of therapy for the elderly. However, LDL-lowering drugs can be considered when they are at established CHD, higher risk because of multiple risk factors, or advanced subclinical atherosclerosis. The association of triglycerides level or HDL-cholesterol level and atherosclerotic diseases has been well defined in the elderly.

Aged↗

[Selection of appropriate antimicrobial agents to test and report by clinical microbiology laboratories].

Clinical microbiology laboratories in Japan have not yet established standards for selecting the most appropriate antimicrobial agents for testing and reporting antimicrobial susceptibility that are comparable to the performance standards of the National Committee for Clinical Laboratory Standards(NCCLS) in the United States of America. Selection of the most appropriate antimicrobial agents for testing and reporting was discussed by a working group(WG) consisting of medical physicians, surgeons, pharmacists, medical technologists and medical microbiologists. The WG agreed on the following basic criteria for the selection of antimicrobial agents: 1) the agent should be useful when screening various resistant bacteria, 2) the agent should serve as a useful guide for physicians and residents when selecting antimicrobial agents, and 3) the agent should be useful for controlling nosocomial infections and resistant bacteria. Clinically isolated microorganisms were classified into 7 groups based on susceptibility to antimicrobial agents. These groups were Staphylococcus spp. or Enterococcus spp., Streptococcus spp. or Haemophilus spp., enterobacteriae, glucose non-fermenting gram positive rods(NFRs), anaerobic bacteria, fungi and mycobacterium. After considering clinical and bacteriological evidence, the WG decided on several antimicrobial agents for testing in clinical microbiology laboratories in Jichi Medical School Hospital. For the NFR group, these were Piperacillin(PIPC), ceftazidime(CAZ), cefepime, imipenem, amikacin and levofloxacin(LVFX). For the enterobacteriae group, these were Amplicillin(ABPC), PIPC, aztreonam, CAZ and LVFX. For the Staphylococcus spp. or Enterococcus spp. group, these were oxacillin, ABPC, vancomycin and gentamicin. We concluded that the most appropriate antimicrobial agent for testing and reporting must be economical and agreed upon at the hospital level, although the ultimate selection must be based on the available clinical and bacteriological evidence.

Anti-Bacterial Agents↗