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Biomedical subjects

X B Zhang

Publications and source records attributed to X B Zhang.

At least 37 records · Page 2Linked to original sources
PubMed1995

[The antihepatoma effect of lyophilized aclacinomycin A polyisobutylcyanoacrylate nanoparticles in vitro and in vivo].

This paper reports the results of experiments on the antihepatoma effects of live targeted drug delivery system--lyophilized aclacinomycin A polyisobutylcyanoacrylate nanoparticle (ACM-IBC-NP) in vitro and in vivo. The median inhibition concentration were found to be 0.28 micrograms.ml-1 and 0.34 micrograms.ml-1 of lyophilized ACM-IBC-NP and ACM respectively in vitro. The inhibition ratio of colony formation were found to be 99% and 88% of lyophilized ACM-IBC-NP and ACM respectively in vitro. The antihepatoma activity was shown to be significantly concentration dependent. The results showed that lyophilized ACM-IBC-NP and ACM possess strong cytotoxicity on human hepatoma cell 7703, and the cytotoxicity was not significantly different between lyophilized ACM-IBC-NP and ACM in vitro. The model of orthotopic transplantation of human hepatoma in nude mice were used for evaluation of the activity of lyophilized ACM-IBC-NP against hepatoma. The tumor inhibition rate were found to be 86.84% for lyophilized ACM-IBC-NP and 46.69% for ACM. The cell proliferative activity of hepatoma were found to be 20.83% by lyophilized ACM-IBC-NP and 72.50% by ACM. All the results indicate that lyophilized ACM-IBC-NP and ACM have clinical application potential and the antihepatoma activity of lyophilized ACM-IBC-NP was obviously higher than that of ACM.

Aclarubicin↗
PubMed1994

[Semiquantitative detection and application about the expression of nitric oxide synthase gene].

Using the Reverse Transcription (RT)-Polymerase Chain Reaction (PCR) method of Martin (1993) for semiquantitation determinating of NOS gene, it was found that NOS mRNA is not only existed in brain, but also distributed extensively in heart, kidney, lung and liver. Among of them, NOS mRNA levels were highest in the brain, followed in descending order by kidney, heart. In addition to endothelial cell, NOS gene was also highly expressed in smooth muscle cells, suggesting that they may be an important site of NOS in organism. Furthermore, NOS mRNA levels were found to decrease significantly in brain, kidney, liver and smooth muscle cell in spontaneous hypertensive rat. These data suggest that pathogeny of hypertension may be related to low expression of NOS gene in these tissues.

Amino Acid Oxidoreductases↗
PubMed1994

[Diagnosis of depressive neurosis].

We studied 97 patients who were diagnosed at the time of discharge having depressive neurosis within the period of 1984-1992. They were rediagnosed according to the diagnostic criteria of CCMD-2, dysthymia and mild degree of depression in ICD-10 and DSM-III-R. Only 23 patients were in accord with diagnostic criteria of CCMD-2 and maintained the diagnosis of depressive neurosis. The other 74 patients were diagnosed as having depression (single or recurrent episode) other types of neurosis, bipolar affective disorders (depressive phase or mixed phase) and schizophrenia. These diagnoses were similar to those in ICD-10 and DSM-III-R.

Adult↗
PubMed1993

Antimutagenicity of cell fractions of microorganisms on potent mutagenic pyrolysates.

The inactivation of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 2-amino-6-methyldipyrido[1,2-a: 3',2'-d]imidazole (Glu-P-1) by binding of mutagenic pyrolysate to fractions of microorganisms (their desmutagenic and bio-antimutagenic activity) was investigated. All strains bound Trp-P-1 effectively, but Glu-P-1 to a lesser extent. The Gram-negative bacteria (GNB) could bind about 10-20 micrograms/mg of Trp-P-1 more than the Gram-positive bacteria (GPB), and about 50-60 micrograms/mg more than the yeasts. The cell wall skeletons of all strains tested had great binding ability, but in the cytoplasm of all strains tested it was lower. The peptidoglycan, outer membrane, and glucan isolate from the cell wall skeletons showed the highest binding ability to Trp-P-1. The cell wall skeletons of the tested strains greatly inhibited the mutagenicity induced by Trp-P-1, and to a lower extent that of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx). Although the cultured broth and solution of cells extracted by phosphate buffer (pH 7.0) showed antimutagenicity against Trp-P-1, this activity was lower than the binding of Trp-P-1 to the cells. The cultured broth and freeze-dried cytoplasms of yeast cells showed bio-antimutagenicity towards Trp-P-1, but those of all bacteria tested did not.

Amines↗
PubMed1993

Anticlastogenic and bio-antimutagenic activity of cultured broth of Saccharomyces cerevisiae 28 on mutagens.

The possible anticlastogenic activity and bio-antimutagenic mechanism of the cultured broth of Saccharomyces cerevisiae 28 were examined using in in vivo and in vitro test systems. In the Ames test with Salmonella typhimurium TA100 (SD-) and in the umu-test with S. typhimurium TA1535/psk1002, the cultured broth of S. cerevisiae 28 showed bio-antimutagenic activity against mutagenicity induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ). The cultured broth also showed bio-antimutagenic activity towards reverse mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in Escherichia coli B/r WP2 trp-, but not by UV radiation. It is clear that the cultured broth could inhibit base substitution mutations induced by mutagens. Using mitomycin C (MMC) as a mutagen, the micronucleus test (with bone marrow cells of mice) showed anticlastogenic action when the cultured broth was given orally to mice. Micronucleated polychromatic erythrocytes induced by the mutagen were reduced by about 47% by the cultured broth.

Antimutagenic Agents↗
PubMed1993

Microorganisms in the gastrointestinal tract of the rat prevent absorption of the mutagen-carcinogen 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole.

The extent to which lactic acid bacteria, intestinal bacteria, and yeast from the gastrointestinal tract of rats suppress the absorption of 3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole (Trp-P-1) was investigated. Trp-P-1 was absorbed from the small intestine very rapidly, but in the stomach it was slowly absorbed, requiring 1 or 2 h after administration. When mixtures of Trp-P-1 and freeze-dried microorganisms were administered to rats for 1 h, the amounts of Trp-P-1 absorbed from the small intestine were significantly reduced, and the levels of Trp-P-1 in blood decreased by 40.4-64.7% compared with a control in which only Trp-P-1 was administered. There were no significant differences between the organisms used. In vitro, freeze-dried cells of the strains tested bound 51-97% of Trp-P-1. The Trp-P-1 bound to cells was effectively extracted by aqueous methanol, ethanol, ammonia (50 g/L), and solutions of MgCl2 and CaCl2 (100 mM/mL), but little was extracted by water and solutions of KCl, NaCl, and buffers at various pH values.

Administration, Oral↗
PubMed1992

Prognostic significance of histopathologic subtype and stage in small cell lung cancer.

A study of 149 light microscopic tissue slides from 147 patients with recorded initial diagnoses of small cell lung cancer (SCLC) (114 cases) and undifferentiated carcinoma (35 cases) was undertaken to test the reproducibility and prognostic impact of a new histopathologic subclassification of SCLC proposed by the Pathology Panel of the International Association for the Study of Lung Cancer (IASLC). This study was further designed to test the impact of clinical stage, age, sex, and race on survival. The tissue slides were blindly reclassified as SCLC or non-SCLC by a panel of five pathologists with no knowledge of the initial diagnosis. The SCLCs were divided into the three subtypes outlined by the IASLC pathology panel: small (classic or pure), mixed (small cell/large cell), and combined (small cell/squamous carcinoma or small cell/adenocarcinoma). Small cell lung cancer was clinically staged as local, regional, or distant. Consensus diagnosis (defined as agreement by at least three of the five pathologists) was achieved in 144 (96.6%) of the 149 cases. Of these 144 cases, 124 were reclassified as SCLC (115 [92.8%] small, five [4.0%] mixed, and four [3.2%] combined) and 20 were classified as non-SCLC. The median lengths of survival for the small, mixed, and combined subtypes were 225, 1,110, and 203 days, respectively (P = .025). Adequate staging data were available in 123 of the 124 SCLC cases. Of the 123 SCLC cases, 27 (21.9%) were local, 22 (17.9%) were regional, and 74 (60.2%) were distant stage. The median lengths of survival for the local, regional, and distant stages were 428, 251, and 111 days, respectively. This association was highly significant (P = .0001). We conclude that stage is the major determinant of survival in SCLC. Mixed subtypes had significantly longer survival times than the small or combined subtypes (P = .025). Survival times were longer for women than for men, and the survival time difference between men and women was significant (P = .0028). We found no significant differences in survival according to age or race.

Carcinoma, Small Cell↗
PubMed1992

Binding of mutagenic pyrolyzates to fractions of intestinal bacterial cells.

The binding of mutagenic pyrolyzates to cell fractions from some gram-negative intestinal bacteria and to thermally treated bacterial cells was investigated. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) were effectively bound by several of the bacterial cells. The cell wall skeletons of all bacteria effectively bound Trp-P-1 and Trp-P-2. Their cytoplasmic fractions retained Trp-P-1 and Trp-P-2, but to a lesser extent than the cell wall skeletons. 2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) was not found in their cytoplasmic fractions. These cell wall skeletons also bound 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-amino-5-phenylpyridine (Phe-P-1), IQ, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX). The amount of each mutagen bound differed with the type of mutagen and the bacterial strain used. The outer membrane of Escherichia coli IFO 14249 showed binding of about 123.7 micrograms/mg of Trp-P-2, and its cytoplasmic membrane bound 57.14 micrograms/mg. Trp-P-2 bound to the bacterial cells was extracted with ammonia (5%), methanol, and ethanol but not with water.

Bacteroides fragilis↗
PubMed1991

In vitro binding of mutagenic pyrolyzates to lactic acid bacterial cells in human gastric juice.

The binding of mutagenic pyrolyzates to freeze-dried cells of Streptococcus cremoris Z-25 was investigated in human gastric juice and compared with the ability of these pyrolyzates to bind in distilled water (pH 6.30). The pH of donated gastric juice ranged from 1.2 to 7.8. Binding that occurred in gastric juice was pH dependent, and binding was affected by NaCl, CaCl2, and MgCl2. Les sof Trp-P-2 was bound in gastric juice at low pH (1.2, 1.48, and 2.1) than at pH 4 to 8. The strain bound simultaneously Trp-P-1, Trp-P-2, and Glu-P-1. The maximum amounts of Trp-P-2 bound to S. cremoris Z-25 were approximately 47.50 micrograms/mg of cells. Freeze-dried cells treated at 120 degrees C for 15 min or 80 degrees C for 3 h showed increased binding of Trp-P-2. However, binding decreased 10% after heating at 120 degrees C for 15 min. Cells nonthermally killed by gastric juice (pH 1.5) had the same Trp-P-2 binding capacity as viable cells. Lactobacillus acidophilus IFO 13951 and Bifidobacterium bifidum IFO 14252 representation of the intestinal bacteria nonthermally killed by gastric juice also showed larger binding of Trp-P-2.

Calcium Chloride↗
PubMed1991

Binding of mutagens by fractions of the cell wall skeleton of lactic acid bacteria on mutagens.

The binding effect of cells and cell fractions, cell wall skeleton, cytoplasm, whole cells, and cell wall skeleton treated by lysozyme and alpha-amylase at 37 degrees C for 5 h, on Trp-P-1 (3-amino-1,4-dimethyl-[5H]pyrido [4,3-b]indole) and Trp-P-2 (3-amino-1-methyl-[5H]-pyrido[4,3-b]indole) were investigated. The cell and cell wall skeleton of Streptococcus cremoris Z-25 had greater binding activity, but cytoplasm and extract of cell wall skeleton did not bind Trp-P-1 and Trp-P-2. When the cells or cell wall skeleton were treated with lysozyme and alpha-amylase, unbound Trp-P-1 and Trp-P-2 concentrations were greater than that of the untreated control. It is possible that cell walls may be involved in the binding of mutagenic pyrolyzates to lactic acid bacteria. The cell wall skeleton of S. cremoris Z-25, Lactobacillus acidophilus IFO 13951, and Bifidobacterium bifidum IFO 14252 showed binding of Trp-P-1, 2-amino-6-methyldipyrido(1,2-a:3',2'- d)imidazole, 2-amino-5-phenylpyridine, 2-amino-3-methylimidazo(4,5-f)quinoline, 2-amino-3,4-dimethylimidazo(4,5-f) quinoline, and 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline. The cell wall skeleton of S. cremoris group and Streptococcus lactis also showed the binding activity with A N-nitrosodimethylamine. The binding of Trp-P-1 to cell walls was very high, and the binding of mutagenic pyrolyzates was variable with different bacterial species. The peptidoglycan complex and polysaccharides liberated from cell wall skeleton of S. cremoris Z-25 showed strong binding of Trp-P-2. Peptidoglycans has a binding effect of about 19.86 micrograms/mg; polysaccharides had a binding effect of 14 micrograms/mg.

Bifidobacterium↗
PubMed1990

Antimutagenicity and binding of lactic acid bacteria from a Chinese cheese to mutagenic pyrolyzates.

The microbiological characteristics of Nai Ge Da, a traditional cheese in China, was investigated. The lactic acid bacteria species were identified as Streptococcus cremoris, Streptococcus lactis ssp. diacetylactis, Streptococcus faecalis, and Leuconostoc paramesenteroides, Leuconostoc dextranicum, and Leuconostoc mesenteroides. Streptococcus cremoris, and Leuconostoc paramesenteroides were the dominant strains. The antimutagenicities and binding of strains of S. cremoris and S. lactic ssp. diacetylactis to mutagenic pyrolyzates was investigated. The lyophilized cells of strains showed the highest inhibitory effect on the 3-amino-1,4-dimethyl-[5H]pyrido[4,3-b] indol (Trp-P-1) and 3-amino-1-methyl-[5H]pyrido[4,3-b] indol (Trp-P-2), but many strains had no significant inhibition against 2-amino-6-methyldipyrido[1,2-a:3',2'-d] imidazole (Glu-P-1). The Trp-P-1 and Trp-P-2 were effectively bound to all bacterial cells, but binding of Glu-P-1 to cells was not effective. Among the strains tested, S. cremoris C-25 not only indicated highest binding to Trp-P-1 and Trp-P-2, but it also it had a 25.36% binding ability with Glu-P-1. When all strains were autoclaved for 15 min at 120 degrees C, binding ability to mutagens was reduced by 3 to 19%. The decrease of binding ability of S. cremoris C-25 was much less, being only 2%. After heating at 80 degrees C for 3 h, the binding ability of all strains to mutagenic pyrolyzates was not much different from those of parent viable cells.

Amino Acids↗
PubMed1989

[An epidemiological study of the residual vivax malaria cases in Huanghuai plain].

In order to get more knowledge of the epidemiological characteristics of the residual cases of vivax malaria in Huanghuai Plain at the present time, a case-control study was carried out from March to May, 1986 in Zhoukou Prefecture, Henan Province and in Xuzhou City, Jiangsu Province. In both areas, the incidence of vivax malaria in 1985 was lower than 1%. The data were analyzed with the conditional logistic multi-regression model and calculated by using Apple II microcomputer. All the malaria cases selected were within an interval less than 20 days (N.B. The incubation interval of vivax malaria is 20 days) during the transmission season because the cases should be independent of each other and fit with logistic multi-regression model. Three controls were matched for each case at random, including a neighbour person in the same village and a person outside the village. The questionnaire contained a total of 31 relevant items of the subjects, families and villages. Six risk factors (personal history of malaria, family member's history of malaria, number of cases in the village in 1984, direction of breeding place, using mosquito-net and number of livestock) related to malaria transmission were obtained through the analysis of the model. The results were in accord with actual epidemiological characteristics in the region, indicating that the conditional logistic multi-regression model can be applied to epidemiological analysis (study) under controlled conditions and provided quantitative method for analysis of socio-economic effects on malaria. The distribution of the cases and their affecting factors were discussed.

Animals↗