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Biomedical subjects

Jun Kato

Publications and source records attributed to Jun Kato.

29 records · Page 2Linked to original sources

[Hematopoietic stem cell transplantation in the second or later complete remission in acute promyelocytic leukemia initially treated with all-trans retinoic acid].

Despite the use of all-trans retinoic acid (ATRA) as the first-line treatment for acute promyelocytic leukemia (APL), relapse occurs in about 20% of cases. Most relapsing APL patients can achieve second remission (CR2) following ATRA combined with chemotherapy or arsenic trioxide. Stem cell transplantation (SCT) has been widely adopted in CR2, but optimal SCT (auto- or allo-SCT) remains controversial. We analyzed the outcomes for 8 APL patients initially treated using ATRA, who relapsed, achieved CR2 and underwent auto-SCT (n = 4) or allo-SCT (n = 4). The mean age of patients who underwent allo-SCT was 39 years. Minimal residual disease (MRD) just prior to SCT was positive in 1 patient and negative in 3. Engraftment was achieved in all patients, but 2 patients died of transplantation-related complications within 6 months. Complete molecular remission has been maintained in the remaining 2 patients. The mean age of patients who underwent auto-SCT was 48 years. MRD just prior to SCT was negative in all 4 patients. Complete molecular remission has been maintained in all 4 patients (mean follow-up, 3 years 9 months). The results for auto-SCT are favorable in patients with MRD-negative APL.

Adult↗

Daily concentrations of trace metals in aerosols in Beijing, China, determined by using inductively coupled plasma mass spectrometry equipped with laser ablation analysis, and source identification of aerosols.

This paper describes the daily concentrations of trace metals and ionic constituents in the aerosol of Beijing, China from March 2001 to August 2003. Daily PM10 concentrations were also measured from September 2001 to August 2003. The daily average PM10 concentration at Beijing, China from September 2001 to August 2003 was 171+/-117 microg m(-3) (n = 673), which is 5-fold higher than at Yokohama, Japan. Trace metal concentrations were analyzed by using inductively coupled plasma mass spectrometry equipped with a laser ablation sample introduction (LA/ICP-MS), which is a rapid and simultaneous method for multi-element analysis. The daily average metal concentrations in TSP in Beijing from March 2001 to August 2003 were: Al: 3.5+/-2.4 (n = 727), Ti: 0.47+/-0.35 (n = 720), V: 0.013+/-0.010 (n = 716), Cr: 0.019+/-0.015 (n = 618), Mn: 0.24+/-0.16 (n = 730), Fe: 5.5+/-3.9 (n = 728), Co: 0.0046+/-0.0055 (n = 629), Ni: 0.022+/-0.024 (n = 680), Cu: 0.11+/-0.11 (n = 660), Zn: 0.77+/-0.60 (n = 726), As: 0.048+/-0.047 (n = 731), Se: 0.010+/-0.010 (n = 550), Cd: 0.0068+/-0.0082 (n = 709), Sb: 0.033+/-0.036 (n = 687), and Pb: 0.43+/-0.50 (n = 728) (unit, microg m(-3)). All the metal concentrations in TSP in Beijing, China were 1.7-21.8 times higher than those in TSP in the center of Tokyo, Japan. Notably, As concentrations in TSP in Beijing were 20-fold higher than those in Tokyo. Source identification of aerosols in Beijing was carried out by using the chemical mass balance (CMB) receptor model, with the daily concentration of metals in the aerosol. The major primary sources of the aerosol of Beijing were considered to be soil dust and coal combustion. Vehicle exhaust contribution tended to increase.

Journal Article↗

Comprehensive search for chicken W chromosome-linked genes expressed in early female embryos from the female-minus-male subtracted cDNA macroarray.

In order to seek chicken W chromosome-linked genes expressed significantly earlier than the time of gonadal differentiation, female-minus-male-subtracted cDNA macroarrays were prepared from day 2 (Hamburger-Hamilton stages 12-13), day 3 (stages 19-20) and day 4 (stages 24-25) embryos. From a total of 15-744 macroarrayed cDNA clones, 610 clones exhibiting significantly female-specific expression were selected. When each one of the 610 cDNA clones was used as a probe in Southern blot hybridization with male or female chicken genomic DNA, 62 clones, grouped into eight (A-H) types according to their patterns of hybridization, were considered to be derived from W chromosome-linked genes. When representative cDNA clones in each type were sequenced, clones derived from two known W-linked genes; SPIN-W and ATP5A1W , and from two hitherto unknown W-linked genes, represented by 2d-2D9 and 2d-2F9 clones, were identified and their localizations on the W chromosome were confirmed by fluorescence in-situ hybridization. The 2d-2D9 sequence has no significant homology with other genes in databases but 2d-2F9 has a region which shows partial homology to the consensus sequence of the AAA ATPase superfamily. Both 2d-2D9 and 2d-2F9 sequences are found in contigs of undetermined chromosome-linkage in the Draft Chicken Genome Sequence.

Animals↗

[Activities of antimicrobial agents against 8,474 clinical isolates obtained from 37 medical institutions during 2000 in Japan].

A survey was conducted to determine the antimicrobial activity of fluoroquinolones and other antimicrobial agents against 8,474 clinical isolates obtained from 37 Japanese medical institutions in 2000. A total of 25 antimicrobial agents were used, comprising 4 fluoroquinolones, 13 beta-lactams, minocycline, chloramphenicol, clarithromycin, azithromycin, gentamicin, amikacin, sulfamethoxazole-trimethoprim, and vancomycin. A high resistance rate of over 85% against fluoroquinolones was exhibited by methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium. Isolates showing resistance to fluoroquinolones among methicillin-resistant coagulase-negative Staphylococci, Enterococcus faecalis, and Pseudomonas aeruginosa from UTI accounted for 30-60%. However, many of the common pathogens were still susceptible to fluoroquinolones, such as Streptococcus pneumoniae (including penicillin-resistant isolates), Streptococcus pyogenes, methicillin-susceptible S. aureus (MSSA), methicillin-susceptible coagulase-negative Staphylococci, Moraxella catarrhalis, the Enterobacteriaceae family, and Haemophilus influenzae (including ampicillin-resistant isolates). About 85% of P. aeruginosa isolated from RTI were susceptible to fluoroquinolones. In conclusion, this survey of sensitivity to antimicrobial agents clearly indicated trend for increasing resistance to fluoroquinolones among MRSA, Enterococci, and P. aeruginosa isolated from UTI, although fluoroquinolones are still effective against other organisms and P. aeruginosa from RTI as has been demonstrated in previous studies.

Anti-Bacterial Agents↗

Radiation-induced reactions via the lowest excited states in cinnamic acid crystals.

Radiation-induced reactions of cinnamic acid derivatives have been examined and compared with photoreactions in the crystalline state; all the reaction products were exactly the same as those of the photoreactions, indicating that the reactions proceed only via the lowest excited state to give [2 + 2] cycloadducts, E/Z isomerization products, or starting molecules.

Journal Article↗

Interferons specifically suppress the translation from the internal ribosome entry site of hepatitis C virus through a double-stranded RNA-activated protein kinase-independent pathway.

Interferon (IFN) therapy is used worldwide as the best available treatment for hepatitis C virus (HCV) infection; however, little is known about how IFN or other drugs work against liver diseases. The effect of 6 drugs (glycyrrhizin, ursodeoxycholic acid, ribavirin, methylprednisolone, IFN-alpha, and IFN-beta) on HCV RNA translation from the HCV internal ribosome entry site (IRES) was investigated, using a bicistronic reporter containing the HCV IRES. IFNs suppressed both cap-dependent and HCV IRES-dependent translation, with HCV IRES-dependent translation being more significantly suppressed. In contrast to HCV IRES, IFN did not suppress either foot-and-mouth disease virus IRES-dependent or encephalomyocarditis virus IRES-dependent translation more than it suppressed cap-dependent translation. Moreover, dominant inhibition of HCV IRES-dependent over cap-dependent translation depended neither on the double-stranded RNA-activated protein kinase activation nor on La protein function. These results indicate a novel antiviral effect of IFNs against HCV.

Anti-Infective Agents↗

Hepatitis C virus NS4A and NS4B proteins suppress translation in vivo.

Many viruses can inhibit protein synthesis in their host cells by targeting translation ("translational shutoff"). There are few reports on the effects of hepatitis C virus (HCV) infection on protein synthesis, because of the lack of a reproducible tissue culture system for HCV. In this study, the influence of seven HCV proteins (core, NS2, NS3, NS4A, NS4B, NS5A, NS5B) on protein synthesis was examined using a reporter assay. In addition, it was determined whether the HCV proteins inhibit protein synthesis via transcription or translation using an RNase protection assay and the effect of HCV proteins on translation from the HCV internal ribosome entry site (IRES) was also examined using a bicistronic reporter. Of the seven HCV proteins, NS4A and NS4B proteins inhibited cellular protein synthesis by targeting the process of translation. They also inhibited translation from the HCV IRES. Moreover, NS4A protein, induced under the control of doxycycline, inhibited the proliferation of HeLa cells. In conclusion, HCV NS4A and NS4B proteins have an effect of translational inhibition. This novel function may be involved in HCV infection and help its survival in host cells.

Animals↗

Relationship between age and site of colorectal cancer based on colonoscopy findings.

BACKGROUND: Colorectal cancer occurs more frequently in older people. Because the population of aged persons is increasing, a better understanding of the characteristics of colorectal cancer with respect to age would be useful. The purpose of this study was to determine whether there is any relationship between the site of colorectal adenoma and adenocarcinoma in the colon and age. METHODS: Colonoscopy was performed (September 1995 to December 1998) on 2942 consecutive patients (1907 men, 1035 women; mean age 61 years, range 11 to 95 years) with no history of colorectal adenoma, adenocarcinoma, or inflammatory bowel disease. The occurrence of colorectal neoplasia, histologically proven as adenoma or adenocarcinoma, was analyzed for a possible association between site in the colon and patient age. RESULTS: Adenocarcinoma was found in 191 patients (196 lesions). The proportion of patients with right-sided colonic adenocarcinoma increased with patient age: < 50 years, 15% (2/13); 50 to 59 years, 21% (8/39); 60 to 69 years, 32% (18/57); 70 to 79 years, 42% (25/49); > or =80 years, 57% (16/28). The proportion of patients with right-sided adenoma did not significantly differ among age groups: < 50 years, 40% (98/246); 50 to 59 years, 41% (280/678); 60 to 69 years, 46% (459/1001); 70 to 79 years, 53% (270/508); and > or =80 years, 57% (87/152). CONCLUSION: The frequency of right-sided colon cancer increases with patient age. Hence, colonoscopy may be indicated in the elderly for colorectal cancer screening. Over half of colon carcinomas may be missed if sigmoidoscopy alone is used for screening.

Adenocarcinoma↗