Biomedical subjects

Junko Sato

Publications and source records attributed to Junko Sato.

28 records · Page 2Linked to original sources

PubMed2004

Recovery of the susceptibility of isolated bacterium achieved by giving long-established antibiotics as prophylaxis against postoperative infections.

PURPOSE: To evaluate the effectiveness of operative antibiotic therapy we changed the antibiotics and examined the susceptibility of the postoperative infection. METHODS: We studied 4 593 patients who underwent gastrointestinal surgery during the last 12.5 years, and examined the changes in intraoperative antibiotics, the return of bacteria isolated from infectious sites, the trends in frequency of Methicillin-resistant Staphylococcus aureus (MRSA) isolation, and changes in the antibiotic susceptibility of Pseudomonas aeruginosa and Bacterioides fragilis. We changed the antibiotics to Cefazolin (CEZ) for upper gastrointestinal tract surgery and cholecystectomy, and to Cefotiam (CTM) for colonic, liver, and pancreatic surgery. We also reduced the period of drug administration. RESULTS: The rate of MRSA infections decreased, the rate of P. aeruginosa infections was always under 20% and the rate of B. fragilis infections increased. After the guidelines of drug susceptibility were prepared, the minimum inhibitory concentrations (MICs) of Cefsulodin (CFS) and Piperacillin (PIPC) for P. aeruginosa and of Latamoxef (LMOX) and PIPC for B. fragilis, decreased. CONCLUSION: The use of antibiotics considered comparatively old for the prophylaxis of postoperative infection prevented the emergence of MRSA-like resistant strains, influenced changes in Gram-negative bacteria drug susceptibility, and led to an overall reduction in multiple drug resistance.

Anti-Bacterial Agents↗

PubMed2004

Pharmacokinetic-pharmacodynamic analysis of fluoroquinolones against Bacillus anthracis.

Based on the pharmacokinetic-pharmacodynamic (PK-PD) parameters of ciprofloxacin in rhesus monkeys, the efficacies of levofloxacin, sparfloxacin, norfloxacin, and tosufloxacin against anthrax in humans were examined. The optimal PK-PD parameter for the prophylaxis or treatment of infection with Bacillus anthracis is not clearly defined. To evaluate the efficacy of fluoroquinolones against anthrax, PK-PD parameters and the protein-binding effect of fluoroquinolones are used. B. anthracis is very susceptible to fluoroquinolones in vitro, and levofloxacin, sparfloxacin, and tosufloxacin may be as effective against anthrax as ciprofloxacin by PK-PD analysis. However, additional studies of the in vivo model are necessary to define more clearly efficacy against anthrax and the pharmacodynamic relationship of fluoroquinolones.

Anthrax↗

PubMed2003

Occan, a novel transposon in the Fot1 family, is ubiquitously found in several Magnaporthe grisea isolates.

We investigated a DNA fragment and its flanking region deleted in the spontaneous Pi-a virulent mutant of Magnaporthe grisea Ina168. A new transposon-like sequence was identified from a region adjacent to the deleted fragment and was named Occan. Occan contained a 2,259-bp ORF interrupted by one 63-bp intron and had both a TA dinucleotide and 77 bp of perfect inverted repeats at both termini, without direct repeats. These features indicated that Occan is a member of the Fot1 family. RT-PCR analysis confirmed the expression of the putative transposase and the presence of an intron. Southern analysis of pulse-field gel electrophoresis-separated chromosomes indicated that Occan was dispersed in all chromosomes of the rice pathogen, Ina168. Copy numbers of Occan were also preserved in a host-specific manner amongst M. grisea isolates. In particular, rice pathogens contained a large number of the element inserted into their genome. Phylogenetic analysis with other known members of the Fot1 family revealed that Occan was dissimilar to any other known elements and it is thus proposed that Occan be separated to a new subfamily.

Amino Acid Sequence↗

PubMed2003

Virological and biochemical relapse according to YMDD motif mutant type during long-term lamivudine monotherapy.

Whether the type of lamivudine-resistant virus in hepatitis B virus (HBV) influences the clinical outcome, it is not completely understood. We evaluated the serial changes in YMDD motif mutant in 60 Japanese genotype C-HBV patients who received long-term lamivudine monotherapy. YIDD or YVDD alone tended to stop shifting to the mixed type (YVDD and YIDD) within 12 months after the detection of mutant virus. Hence, the characteristics, virological relapse (DNA breakthrough) and biochemical relapse (breakthrough hepatitis) of 49 patients, who could be classified into three types (continuous YVDD, continuous YIDD, and the mixed type), were investigated. YVDD and YIDD type tended to have the opposite background with regard to age, histology, and viral load. The mixed and YIDD types tended to have similar backgrounds, except for viral load. In the mixed type, both the HBeAg-positive rate and viral load as risk factors for emergence of the mutant tended to be high. Mutant virus, DNA breakthrough and breakthrough hepatitis emerged significantly earlier in the mixed type than the two other types. The incidence of severe breakthrough hepatitis accompanied by icteric flare-up tended to be higher in the mixed type than the other types. Our results suggest that the YMDD motif mutant type might emerge from different backgrounds and modulate the virological and biochemical relapse after the emergence. Large-scale studies of each mutant type should be conducted in the future to confirm these findings.

Adult↗

PubMed2003

Clinical features of hepatitis B virus genotype A in Japanese patients.

BACKGROUND: Hepatitis B virus (HBV) genotype A is predominant in northern Europe and central Africa. In the present study, we examined the clinical features associated with HBV genotype A disease in the Tokyo metropolitan area. METHODS: We investigated 53 cases of HBV surface antigen (HBsAg)-positive Japanese patients with HBV genotype A. The 53 cases were further classified as to their serum alanine aminotransferase (ALT) status being within the normal range (asymptomatic carriers, n = 17), chronic hepatitis (n = 15), liver cirrhosis (n = 4), and acute hepatitis (n = 17). RESULTS: Chronic hepatitis patients had significantly higher HBV DNA levels (P = 0.003) and hepatitis B e antigen (HBeAg) positivity rates at the initial visit than did asymptomatic carriers or patients with liver cirrhosis (P = 0.003 and P = 0.054, respectively). The efficacy of treatment (HBeAg seroconversion rate) was 75% in 12 chronic hepatitis patients, which was excellent. A family history of HBsAg positivity was identified in eight (15%) families (five asymptomatic carriers, three with chronic hepatitis). However, none of the mothers in the study was positive for HBV genotype A. CONCLUSIONS: Maternal transmission of HBV has often been reported in Japan, but our present findings suggest that horizontal infection of HBV genotype A is more prevalent in the Tokyo metropolitan area. Our data indicate that HBV genotype A exhibits a mode of infection different from that of conventional HBV previously seen in Japan.

Adolescent↗

PubMed2003

Changes in environmental humidity affect the water-holding property of the stratum corneum and its free amino acid content, and the expression of filaggrin in the epidermis of hairless mice.

BACKGROUND: Seasonal changes affect the condition of skin and may trigger various cutaneous disorders. OBJECTIVE: To clarify the effects of the environmental humidity on the skin pathology, we studied the effects of the humidity on a water-holding function of the stratum corneum. METHODS: We evaluated the skin surface conductance, amino acid in the stratum corneum, and immunoreactivity of filaggrin of the epidermis of hairless mice kept in different environmental humidity. RESULTS: Skin surface conductance in the stratum corneum of hairless mice 3-7 days after transfer from a humid environment (>80% relative humidity) to a dry (<10% relative humidity) environment, was significantly lower than that of the mice transferred from a normal environment (relative humidity=40-70%) to a dry environment. The free amino acid content in the stratum corneum significantly decreased 24 h after we transferred the mice from a normal to a dry condition, then it recovered to the original level within 3 days, while the mice transferred from a humid to a dry condition showed a significantly lower amino acid content even 7 days after the transfer. No obvious change was observed in the relative composition of the major components of the free amino acids during the experiments. Immunoreactivity of filaggrin, which is the main precursor of free amino acids in the stratum corneum, also became faint in the epidermis of the mice transferred from a humid or normal to a dry environment. CONCLUSION: These results suggested that a drastic decrease in the environmental humidity reduced the total free amino acid generation and consequently induced skin surface dryness in the stratum corneum.

Amino Acids↗

PubMed2003

Precore wild-type hepatitis B virus with G1896 in the resolution of persistent hepatitis B virus infection.

OBJECTIVE: Factors influencing the resolution of persistent hepatitis B virus (HBV) infection were sought for. METHODS: The loss of hepatitis B surface antigen (HBsAg) from serum was correlated with mutations in HBV DNA for a hepatitis B e antigen (HBeAg)-minus phenotype in patients infected with HBV genotype C and positive for HBeAg at presentation. RESULTS: HBeAg turned negative in all the 22 patients in whom HBV infection resolved, but only in 11 of the 25 patients with severe liver diseases (100 vs. 44%, p = 0.0001). The precore wild type (G1896) persisted significantly more frequently in the 22 patients in whom HBV infection resolved than in the 11 patients who developed decompensated liver cirrhosis or hepatocellular carcinoma (15/22 or 68% vs. 1/11 or 9%, p = 0.005). The double mutation in the core promoter (T1762/A1764) was comparably frequent in the two groups of patients at presentation (14/22 or 64% vs. 7/11 or 64%) and >15 years thereafter (18/22 or 82% vs. 10/11 or 91%). CONCLUSION: The precore wild type (G1896) would seem to facilitate the resolution of HBV infection, while the precore mutant (A1896) may induce severe liver diseases in patients with HBeAg-positive chronic hepatitis who have lost HBeAg from serum.

Adult↗

PubMed2002

Viral genotypes and response to interferon in patients with acute prolonged hepatitis B virus infection of adulthood in Japan.

Acute hepatitis B virus (HBV) infection was diagnosed in 57 adults admitted to Toranomon Hospital in Tokyo, Japan. Genotypes of HBV were determined by a serological method and compared to those in 1,077 patients with chronic hepatitis B. The distribution of genotypes were: genotype A (acute, 22.8% vs. chronic, 1.9%; P < 0.00001); B (14.0% vs. 9.4%); C (43.9% vs. 87.7%, P = 0.004); D (1.8% vs. 0.2%); F (1.8% vs. 0.2%); and unable to be typed (15.8% vs. 0.6%, P = 0.001). The infection persisted in seven (12%) of them. They included six (86%) of the seven patients who received prednisolone or glycyrrhizin during an acute phase of illness and one of the 41 (2%) who did not (P = 0.01). Interferon was given to the seven patients with acute prolonged HBV infection, and four of them responded by clearing hepatitis B e antigen (HBeAg) and surface antigen (HBsAg) from serum. Of the four responders, one was infected with HBV genotype B and three with genotype C. HBsAg persisted in the remaining three patients all of whom were infected with HBV genotype A, and HBeAg stayed positive in one of them. These results indicate that HBV genotype A prevails in Japanese patients with acute hepatitis B, and suggest a high efficacy of interferon in the adult patients with acute prolonged HBV infection, except in those infected with HBV genotype A.

Acute Disease↗

PubMed2002

Clinical characteristics of patients infected with hepatitis B virus genotypes A, B, and C.

BACKGROUND: The aim of the present study was to evaluate the clinical characteristics at first hospital consultation, according to the genotype of hepatitis B virus (HBV), in patients with chronic liver diseases and positivity for hepatitis B surface antigen (HBsAg) in metropolitan Tokyo. METHODS: The subjects consisted of 1077 patients with chronic liver diseases who were HBsAg-positive. HBV genotype was determined by an enzyme-linked immunosorbent assay (ELISA), using PreS2 monoclonal antibody, which is specific for HBV genotypes in the PreS2 region. RESULTS: The proportion of patients with genotype A was 2% (20 patients), genotype, B 9% (101 patients), and genotype C, 88% (945 patients), while 11 patients (1.0%) had other genotypes, including 2 (0.2%) each with genotypes D and F, and 7 (0.6%) that were untypeable. Patients with genotype A were significantly (P = 0.049) more likely to be positive for Hepatitis B envelope antigen (HBeAg) at the first consultation compared with those with genotype B. Patients with genotype B were significantly more likely to be HBeAg-negative at the first consultation compared with those with genotype A (P = 0.049) and genotype C (P = 0.001), significantly more likely to show minimal hepatic fibrosis (P = 0.003), and least likely to develop liver cirrhosis (P = 0.005). Patients with genotype C were likely to be HBeAg-positive (P = 0.001) and to have a positive family history of HBV infection (P = 0.0002). CONCLUSIONS: The clinical features of patients with HBV infection in metropolitan Tokyo varied depending on the HBV genotype.

Adolescent↗

PubMed2002

Abrupt decreases in environmental humidity induce abnormalities in permeability barrier homeostasis.

Previous reports demonstrated that long-term exposure to extremes in humidity influence permeability barrier homeostasis. Here the effects of a sudden shift from a high humidity to a dry environment were studied. Mice were initially maintained in either a humid (> 80% relative humidity) or normal environment (relative humidity = 40-70%), and then transferred to a dry environment (< 10% relative humidity). Within 2 d of transfer from a humid to a dry environment a 6-7-fold increase in transepidermal water loss occurred that returned to normal within 7 d. No increase in transepidermal water loss occurred in response to a switch from a normal to a dry environment. At a time when barrier function was abnormal, both stratum corneum hydration and pH were normal, indicating that the mechanisms that regulate these functions differ. Following transfer from a humid to dry environment, electron microscopy revealed a marked decrease in: (i) lamellar bodies in the outermost stratum granulosum; (ii) deposition of lamellar body contents at the stratum granulosum-stratum corneum interface; and (iii) the quantity of intercellular lamellae in the stratum corneum, which together could account for the barrier abnormality. Transfer of mice from a normal to a dry environment rapidly stimulated epidermal proliferation, whereas animals switched from a humid to a dry environment displayed a delayed increase in proliferation that might also contribute to the barrier abnormality. The present study demonstrates that sudden changes from a high to a low humidity environment results in abnormal barrier function, which could adversely influence the incidence and/or severity of skin disorders.

Animals↗