In vivo inhibition of multivitamin on the formation of hemoglobin adduct in 4-aminobiphenyl-treated rat.
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Aminobiphenyl Compounds↗
Biomedical subjects
Z L Jin
Publications and source records attributed to Z L Jin.
Investigation of protein-styrene oxide adducts as a molecular biomarker of human exposed to styrene.
Hemoglobin-styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein-styrene oxide adducts in different biological samples with modified Raney-Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro; rat blood reacted with styrene or styrene oxide in vivo; vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose-response relationship between reacting dose of styrene oxide or styrene and amount of protein-styrene oxide adducts in both in vitro and in vivo experiments. For human samples, a dose-response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.
Animals↗
[The role of theophylline in the improvement of scop-induced learning and memory impairment].
Adenosine and ACh contents in hippocampus, striatum region around the nucleus of basal meynert (NBM) and the frontal and temporal parts of rat cortex were measured by a high performance liquid chromotography-electronic detector (HPLC-ECD). Adenosine content in 18~20 month-old rats was significantly higher than that of 3~6 month-old rats, while ACh content in 18~20 month-old rats was lower than that of 3~6 month-old ones. Learning and memory impairment models were established by induction of SD rats with scopolamine (0.5 mg/kg, ip), which were injected with an adenosine receptor antagonist theophylline (1.0 mg/5 microliter, icv), and the step-down test was performed. The error frequency in the step-down test decreased significantly (P<<0.05), and the retention time was longer than that of control. Furthermore, ACh content increased in all the three different brain regions. The above results suggest that adenosine may play an important role in senile learning and memory impairment, and theophylline may improve scopolamine-induced learning and memory impairment by increasing ACh content. In consequence, theophylline could be a promising drug for ameliorating senile learning and memory impairment.
Acetylcholine↗
[Epidemiological study of hepatitis C virus (HCV) infection in plasmapheresis and blood donors].
We actively adopted method to control hepatitis C (HC) epidemic in blood sampling. ELISA was used to detect anti-HCV antibody in different groups of 2348 blood donors. The positive rates of anti-HCV for plasmaphersis and whole blood donors were 0.58% (2/343) and 1.34% (27/2005) respectively, with no statistical significance (P > 0.05). The positive rates of anti-HCV for plasmapheresis donors in 1-2 years and over 9 years were 0.99% (7/701) and 0.74% (2/270) respectively. There was no significant difference (P > 0.05) either. The positive rates of anti-HCV for plasmapheresis donors in 1992 and in 1994 were 1.64% (7/426), and 0.58% (2/343). The results showed that HCV infection rate did not increase in plasmapheresis donors, nor did it increase parallel with the increasing gears of blood donnation.
Blood Donors↗
Age-dependent change in the inhibitory effect of an adenosine agonist on hippocampal acetylcholine release in rats.
To investigate the possibility that age-dependent deficits in acetylcholine (ACh) release are precipitated by the alteration of endogenous purinergic activities, the effects of (-)N6-phenylisopropyladenosine (PIA), an adenosine agonist, in modulating K+ (25 mM)-induced [3H]ACh release from the hippocampal slices of young (3-6 months old) and old rats (26-30 months old) were examined. In young rats, PIA (0.1-10 microM) caused a dose-related inhibition of [3H]ACh release from the hippocampal slices and a significant reduction in [3H]ACh release was observed in the presence of 1 microM PIA. In old rats, a similar pattern of PIA suppression of K(+)-induced [3H]ACh release was observed; however, a 10-fold higher concentration of PIA (10 microM) was required to elicit a significant inhibition. This age-dependent reduction in responsiveness to PIA may be due to an enhanced endogenous adenosine activity in aged rats leading to downregulation of the adenosine receptors. This notion is supported by the finding that both the adenosine concentration and activity of 5'-nucleotidase, an enzyme partially governing adenosine synthesis, were increased in the hippocampus of old rats as compared to their younger counterparts.
Acetylcholine↗
Decrease in cold tolerance of aged rats caused by the enhanced endogenous adenosine activity.
During severe cold exposure, old rats (24-28 months) were less capable of maintaining their body temperature compared to young rats (3-6 months) due to lower rate of heat production. Single injection of adenosine deaminase (AD) (converts adenosine to inosine) significantly increased thermogenesis in both young and old rats. However, doubling the dose of AD was required for optimal thermogenic response in old rats. In contrast, the similar enhancements in both thermogenesis and cold tolerance were observed in both young and old rats receiving the same optimal doses of specific adenosine receptor antagonists. These results lead to the suggestion that the lower capability of aged rats to withstand cold exposure could be due to an increase in adenosine stimulation because of the decreased endogenous AD activity rather than an increase in adenosine receptor sensitivity. This notion is further supported by the finding that the AD activity in the neck muscle, a key site for shivering thermogenesis, was significantly lower in old rats as compared to their younger counterparts before and after cold exposure.
Adenosine↗
Analysis of volatile N-nitrosamines in beer and food in China.
Capillary gas chromatography-thermal energy analysis was used for the study of volatile N-nitrosamines in comestibles. The finding of a comparatively high content of N-nitrosodimethylamine in some Chinese beers confirms the results of other authors. We describe studies of Chinese foods and environmental samples carried out in this laboratory in collaboration with epidemiological groups. The concentrations of N-nitrosamines could be correlated with mortality from digestive cancer.
Beer↗
Analysis of mutagenic nitroarenes in carbon black by high-performance liquid chromatography.
A method was developed for the analysis of mutagenic nitroarenes in carbon black. The procedure included extraction, pre-separation column chromatography on silica gel, and determination by high-performance liquid chromatography (HPLC) using a diode-array detector. Different solvents, such as dichloromethane, benzene, toluene, and chlorobenzene were used for the extraction of carbon black. It was found that chlorobenzene yielded the highest amount of extracted material. The pre-separation, the optimization of the HPLC separation, the selection of detection wavelengths, and the calibration curve are discussed. 3-Nitro-9-fluorenone was detected in a treated carbon black, which is used for making carbon ink. The identification of peaks in the sample chromatograms was confirmed by comparing the retention time and the UV spectra with those of standards.
Carbon↗
High-performance liquid chromatographic studies of environmental carcinogens in China.
A review of high-performance liquid chromatographic (HPLC) studies of environmental carcinogens in China is presented, including the HPLC analysis of the ubiquitous polynuclear aromatic hydrocarbons (PAHs) and of nitro-substituted PAHs and aflatoxins. Some results of applying these methods to air particulates, emissions, smoke from coal combustion and water and to the inhibition of benzo[a]pyrene metabolism are reported.
Aflatoxins↗
Potent mutagenic impurities in a commercial sample of 3-nitro-9-fluorenone.
A commercial sample of 3-nitro-9-fluorenone was a potent mutagen in the Ames Salmonella assay, producing 1000 TA98 net revertants per plate at 0.76 microgram/plate without the presence of liver homogenates (-S9). After purification by high-pressure liquid chromatography (HPLC), 3-nitro-9-fluorenone was found to be at least 6 times less active than the parent sample. The commercial sample was fractionated by HPLC and the mutagenic impurity peaks collected and subjected to high-resolution mass spectrometry (HRMS). The mass spectra of 2 potent mutagenic fractions showed the principal molecular species to be a dinitrofluorenone and an acetamidomononitrofluorenone. Samples of synthetic 2,7-dinitro-9-fluorenone and 2-acetamido-3-nitro-9-fluorenone had mutagenic activities, HPLC retention times, and mass spectra characteristics similar to the mutagenic impurity fractions collected from the commercial sample.
Chromatography, High Pressure Liquid↗