Biomedical subjects

K Saeki

Publications and source records attributed to K Saeki.

367 records · Page 21Linked to original sources

PubMedDate not supplied

Relationships between bacterial tolerance levels and forms of copper and zinc in soils.

The effects of various fractions of copper (Cu) and zinc (Zn) on soil bacteria were evaluated by the heavy metal tolerance level of the bacterial community (IC50) in soil samples collected near a mine. The IC50 values had no relationship with the total concentrations of Zn and Cu in the soils, but were weakly correlated with the 0.05 M CaCl2-extractable form of each metal in the soils (Cu: R2 = 0.670, p < 0.01; Zn: R2 = 0.453, p < 0.05). It was found that the IC50 correlated strongly with the total concentration of each metal in the extracts from water-saturated soil samples, described below as "soil solution" (Cu: R2 = 0.789, p < 0.01; Zn: R2 = 0.617, p < 0.01). The speciation of these metals in the soil solutions was estimated using an equilibrium thermodynamic computer model, SOILCHEM. Simulated free Cu ion ranged from 18 to 98% of total Cu, and organic complexes of Cu ranged from < 1 to 56%. In all samples, Zn existing as the free ion was estimated to be more than 80% of total Zn in the soil solutions. The IC50 values were also correlated with the estimated free metal ion activities, but with slightly lower correlation coefficients than found for total concentration in the soil solutions (Cu: R2 = 0.735, p < 0.01; Zn: R2 = 0.610, p < 0.01). The results suggest that not only high metal ion activities, but also total dissolved metal concentrations in soil solutions may affect the bacterial community.

Adaptation, Physiological↗

PubMedDate not supplied

Bcl-2 expression and prognosis in childhood acute leukemia. Children's Cancer and Leukemia Study Group.

Bcl-2 expression and its prognostic value were evaluated in 42 children with acute leukemia. The Bcl-2 expression of the leukemic blast cells was measured quantitatively by flow cytometry and was further analyzed by the simultaneous immunostaining of Bcl-2 with the surface membrane antigens, DNA, Ki-67 antigen. All of the cases showed a consistent expression of Bcl-2 protein; virtually all leukemic lymphoblasts were Bcl-2 positive. Although the expression of Bcl-2 varied widely from 7 to 80 x 10(3) MESF units, no significant difference was found in the mean value between the patients with acute lymphoblastic leukemia and those with acute myeloblastic leukemia. In more than half of the patients with AML, intraclonal heterogeneity of Bcl-2 expression was observed. The expression of Bcl-2 showed no apparent fluctuations during the different phases of the cell cycle. However, the proportion of Bcl-2-positive and -negative cells during the cell cycle was different between ALL and AML patients. In the ALL patients, few Bcl-2-negative cells were detected only in the GI phase, whereas in the AML patients Bcl-2-negative cells were detected in the S and G2/M phases, as well as in the G1 phase. No apparent difference was found in Bcl-2 expression between the Ki-67-negative noncycling population and the Ki-67-positive cycling population. Of the clinical features of these patients, only CD34 expression in the ALL patients was associated with high levels of Bcl-2 expression. In the 28 untreated cases of ALL, high expression of Bcl-2 was not an unfavorable factor for the outcome of this disease.

Adolescent↗

PubMedDate not supplied

The long-term evaluation of pulmonary toxicity following isolated lung perfusion with melphalan in the rat.

The present study was conducted to evaluate the long-term pulmonary toxicity of isolated lung perfusion (ILP) with melphalan in the rat model. F344 rats were treated by ILP with 1 mg of melphalan or buffered hespan (BHE). The rats in the melphalan group were sacrificed randomly 30, 60, 90, 120, 150, and 180 days after the perfusion. Pulmonary toxicity was evaluated by pathological analysis. In the melphalan group, light and electron microscopic findings revealed perivascular and peribronchial edema, and septal thickening with cellular infiltration of the interstitial space 30 days after the perfusion, but all of these changes had disappeared by 60 days. Azan stain showed a slight increase of the connective tissue at the alveolar wall in the melphalan group, but no progressive pulmonary interstitial fibrosis was observed after 180 days. Transmission electron microscopy showed minimal proliferation of the type II pneumocytes of normal appearance in the melphalan group. In conclusion, the long-term pulmonary toxicity of ILP with melphalan is acceptable; however clinical trials of this therapy need to be conducted.

Animals↗

PubMedDate not supplied

Initial daily interferon administration can gain more eradication of HCV-RNA in patients with chronic hepatitis C, especially with serum intermediate viral load.

BACKGROUND/AIMS: We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, especially in patients with intermediate viral load. METHODOLOGY: Consecutive patients who met the inclusion criteria were randomly enrolled into two groups in this study. All patients analyzed could be treated with interferon-alpha for 6 months. Patients in group A were administered 6 million units of interferon-alpha subcutaneously daily initially for 2 weeks and then thrice weekly. Patients in group B were treated with the same dose of interferon-alpha thrice weekly from the first administration. We decided the criteria of complete remission as the absence of serum HCV-RNA at both points of the end of interferon treatment and 6 months later. RESULTS: Due to the relationship between the efficacy and serum viral load, we decided the criteria of the intermediate load as the quantitative value of serum HCV-RNA to be not lower than 10(5.0) and not higher than 10(6.5) copies/ml. Seventy-six and 78 patients, whose genotype and quantitative value of serum HCV-RNA could be measured before treatment, were analyzed in group A and B, respectively. The rate of complete remission in group A (40.8%) was higher than that in group B (25.6%), significantly (p = 0.046). In the intermediate viral load group, the rate of complete remission in group A (52.3%) was significantly higher than that in group B (29.3%) (p = 0.045). In the patients with genotype 1 b virus, the rate of complete remission had a tendency to be higher in group A (33.3%) than in group B (17.4%) (not significant). In the patients with genotype 2, the rate of complete remission was higher in group A (77.8%) than in group B (41.2%) (significant, p = 0.041). CONCLUSIONS: These results suggest that the initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with intermediate viral load in chronic hepatitis C.

Adult↗

PubMedDate not supplied

An epidemiological study on Mycobacterium leprae infection and prevalence of leprosy in endemic villages by molecular biological technique.

One of the most important unsolved questions in epidemiology of leprosy is the highly uneven geographic distribution of the disease. There are many hyperendemic "pockets" in endemic countries. Little is known about the reasons why leprosy is hyperendemic in these areas. We conducted, therefore, a series of epidemiological studies on Mycobacterium leprae infection and prevalence of leprosy in North Maluku district, Maluku Province, Indonesia where leprosy is highly endemic. It was found that considerable number of general inhabitants are seropositive to various mycobacterial antigens and 27% of the villagers were carrying leprosy bacilli on their surface of nasal cavity. These results suggested the importance of M. leprae in the residential environment in infection of the leprosy bacillus and the resulting transmission of the disease. Based on these observations, we conclude that new preventive measures are essential for global elimination of leprosy in addition to early diagnosis and multidrug therapy (MDT).

Antibodies, Bacterial↗

PubMedDate not supplied

Mycobacterium leprae DNA in daily using water as a possible source of leprosy infection.

Some environmental factors were suspected to be sources of leprosy infection according to the results of total survey in the highly endemic villages in Indonesia. M. leprae DNA were detected by PCR from 21 out of 44 water sources used daily by villagers. Prevalence of leprosy among the people using PCR-positive water for bathing and washing was significantly higher than that among the people who used PCR-negative water. No significant difference in prevalence was, however, recognized in case of usage of negative or positive water for drinking. Water was regarded as a reservoir and infectious source of M. leprae. Transmission of leprosy through the contaminated water was strongly suggested by epidemiological analysis.

DNA, Bacterial↗

PubMedDate not supplied

The importance of initial daily administration of interferon alpha for the eradication of hepatitis C virus in patients with chronic hepatitis C: a multicenter randomized trial.

BACKGROUND/AIMS: We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, to clarify a more effective treatment protocol for the eradication of the hepatitis C virus. METHODOLOGY: Consecutive patients who met the inclusion criteria were randomly enrolled in two groups in this study. One hundred and five patients were randomized and assigned to two groups. Patients, who enrolled in group A, were treated with 6 million units of natural interferon-alpha given subcutaneously daily for an initial two weeks and then thrice a week for 22 weeks. Patients, who were enrolled in group B, were treated with the same dose of interferon-alpha given for 26 weeks thrice a week from the first administration. RESULTS: In groups A and B, 58 and 47 patients were analyzed, respectively. At the end of treatment, 37 patients in group A (63.8%) had negative serum HCV-RNA test, compared with 26 in group B (55.3%), but at 6 months after discontinuation of interferon administration, 27 patients in group A (46.6%), compared with 8 in group B (21.3%). The rate of complete remission in group A (46.6%) was higher than that in group B (21.3%) (P<0.01). In patients with genotype 1b virus, the rate of complete remission was higher in group A (31.3%) than in group B (12.5%) (not significantly), and the relapse rate was lower in group A (9.4%) than in group B (37.5%), significantly (p<0.05). CONCLUSIONS: This study suggests that initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with chronic hepatitis C.

Alanine Transaminase↗