Biomedical subjects

H Zhu

Publications and source records attributed to H Zhu.

At least 217 records · Page 12Linked to original sources

PubMed2000

Oxidative stress-associated impairment of proteasome activity during ischemia-reperfusion injury.

Numerous studies indicate a role for oxidative stress in the neuronal degeneration and cell death that occur during ischemia-reperfusion injury. Recent data suggest that inhibition of the proteasome may be a means by which oxidative stress mediates neuronal cell death. In the current study, the authors demonstrate that there is a time-dependent decrease in proteasome activity, which is not associated with decreased expression of proteasome subunits, after cerebral ischemia-reperfusion injury. To determine the role of oxidative stress in mediating proteasome inhibition, ischemia-reperfusion studies were conducted in mice that either overexpressed the antioxidant enzyme glutathione peroxidase [GPX 1(+)], or were devoid of glutathione peroxidase activity (GPX -/-). After ischemia-reperfusion, GPX 1(+) mice displayed decreased infarct size, attenuated neurologic impairment, and reduced levels of proteasome inhibition compared with either GPX -/- or wild type mice. In addition, GPX 1(+) mice displayed lower levels of 4-hydroxynonenal-modified proteasome subunits after ischemia-reperfusion injury. Together, these data indicate that proteasome inhibition occurs during cerebral ischemia-reperfusion injury and is mediated, at least in part, by oxidative stress.

Animals↗

PubMed2000

A new species of oral Streptococcus isolated from Sprague-Dawley rats, Streptococcus orisratti sp. nov.

Taxonomic studies were performed on an unusual oral Streptococcus strain isolated from Sprague-Dawley rats. The isolates were alpha-haemolytic, bile-tolerant, aesculin-hydrolytic and unable to grow in 6.5% NaCl. They fermented lactose, sucrose and trehalose. They were distinguished from other recognized species of oral and viridans streptococci by several biochemical characteristics and by Lancefield's group antigen, as well as by unique DNA-DNA hybridization characteristics. 16S rDNA sequence studies confirmed the genealogical distinctiveness of the species. The results of the study demonstrated that the isolates represented a new species of the oral and viridans streptococci. The name Streptococcus orisratti sp. nov. is proposed for the new species. The type strain is A63T (= ATCC 700640T).

Animals↗

PubMed2000

Characterization of an atrazine-degrading Pseudaminobacter sp. isolated from Canadian and French agricultural soils.

Atrazine, a herbicide widely used in corn production, is a frequently detected groundwater contaminant. Fourteen bacterial strains able to use this herbicide as a sole source of nitrogen were isolated from soils obtained from two farms in Canada and two farms in France. These strains were indistinguishable from each other based on repetitive extragenic palindromic PCR genomic fingerprinting performed with primers ERIC1R, ERIC2, and BOXA1R. Based on 16S rRNA sequence analysis of one representative isolate, strain C147, the isolates belong to the genus Pseudaminobacter in the family Rhizobiaceae. Strain C147 did not form nodules on the legumes alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), red clover (Trifolium pratense L.), chickpea (Cicer arietinum L.), and soybean (Glycine max L.). A number of chloro-substituted s-triazine herbicides were degraded, but methylthio-substituted s-triazine herbicides were not degraded. Based on metabolite identification data, the fact that oxygen was not required, and hybridization of genomic DNA to the atzABC genes, atrazine degradation occurred via a series of hydrolytic reactions initiated by dechlorination and followed by dealkylation. Most strains could mineralize [ring-U-(14)C]atrazine, and those that could not mineralize atrazine lacked atzB or atzBC. The atzABC genes, which were plasmid borne in every atrazine-degrading isolate examined, were unstable and were not always clustered together on the same plasmid. Loss of atzB was accompanied by loss of a copy of IS1071. Our results indicate that an atrazine-degrading Pseudaminobacter sp. with remarkably little diversity is widely distributed in agricultural soils and that genes of the atrazine degradation pathway carried by independent isolates of this organism are not clustered, can be independently lost, and may be associated with a catabolic transposon. We propose that the widespread distribution of the atrazine-degrading Pseudaminobacter sp. in agricultural soils exposed to atrazine is due to the characteristic ability of this organism to utilize alkylamines, and therefore atrazine, as sole sources of carbon when the atzABC genes are acquired.

Agriculture↗

PubMed2000

Characterization of S-triazine herbicide metabolism by a Nocardioides sp. isolated from agricultural soils.

Atrazine, a herbicide widely used in corn production, is a frequently detected groundwater contaminant. Nine gram-positive bacterial strains able to use this herbicide as a sole source of nitrogen were isolated from four farms in central Canada. The strains were divided into two groups based on repetitive extragenic palindromic (rep)-PCR genomic fingerprinting with ERIC and BOXA1R primers. Based on 16S ribosomal DNA sequence analysis, both groups were identified as Nocardioides sp. strains. None of the isolates mineralized [ring-U-(14)C]atrazine. There was no hybridization to genomic DNA from these strains using atzABC cloned from Pseudomonas sp. strain ADP or trzA cloned from Rhodococcus corallinus. S-Triazine degradation was studied in detail in Nocardioides sp. strain C190. Oxygen was not required for atrazine degradation by whole cells or cell extracts. Based on high-pressure liquid chromatography and mass spectrometric analyses of products formed from atrazine in incubations of whole cells with H(2)(18)O, sequential hydrolytic reactions converted atrazine to hydroxyatrazine and then to the end product N-ethylammelide. Isopropylamine, the putative product of the second hydrolytic reaction, supported growth as the sole carbon and nitrogen source. The triazine hydrolase from strain C190 was isolated and purified and found to have a K(m) for atrazine of 25 microM and a V(max) of 31 micromol/min/mg of protein. The subunit molecular mass of the protein was 52 kDa. Atrazine hydrolysis was not inhibited by 500 microM EDTA but was inhibited by 100 microM Mg, Cu, Co, or Zn. Whole cells and purified triazine hydrolase converted a range of chlorine or methylthio-substituted herbicides to the corresponding hydroxy derivatives. In summary, an atrazine-metabolizing Nocardioides sp. widely distributed in agricultural soils degrades a range of s-triazine herbicides by means of a novel s-triazine hydrolase.

Actinomycetales↗

PubMed2000

In vitro MR imaging of hyaline cartilage: correlation with scanning electron microscopy.

OBJECTIVE: Our goal was to determine how the three-dimensional structure of hyaline cartilage affects its MR appearance and to correlate this appearance with detailed structural analysis using scanning electron microscopy and freeze-fracture sectioning techniques. MATERIALS AND METHODS: In vitro 7-T spin-echo MR images of hyaline cartilage specimens from four patients undergoing above-knee amputations were obtained parallel and perpendicular to the main magnetic field. Specimens were imaged with low- and high-power scanning electron microscopy after freeze fracturing. The corresponding images from both techniques were analyzed with specific attention to the three-dimensional structure of the cartilage, collagen fibril orientation, and respective changes in the MR appearance. RESULTS: Freeze fracturing of cartilage reveals a curved fracture plane. Expected changes in signal intensity predicted by the magic angle effect correlated with observed changes in signal intensity across the thickness of the sample. Changes in individual collagen fibril orientation did not correspond to MR layering. CONCLUSION: The three-dimensional organization of collagen in cartilage has a strong influence on the MR appearance of cartilage. This influence is caused by the restriction of water mobility and the resulting magic angle effect caused by curvature of the collagen network, possibly because of the influence on proteoglycan orientation.

Adult↗

PubMed2000

Amyloid formation in the rat: adenoviral expression of mouse serum amyloid A proteins.

Serum amyloid A (SAA) proteins are acute-phase apolipoproteins that are associated with high-density lipoprotein (HDL) particles: SAA proteins are precursors to secondary amyloid fibril proteins and under certain conditions of chronic or recurrent inflammation these proteins are deposited as amyloid fibrils. Of two isotypes found in mouse, SAA1.1 and SAA2.1, only SAA1.1 is deposited into amyloid. The CE/J mouse is unique, in that the only isoform identified is a hybrid between SAA1.1 and SAA2.1 and the mouse does not show amyloid deposition. In the rat, a deletion in the SAA1/SAA2 gene is associated with the absence of protein in the plasma and subsequently no amyloid deposition is detected. We have generated adenoviral vectors to study the expression of SAA proteins on HDL metabolism and amyloid formation. Injection of SAA viruses into rats resulted in expression of the mouse SAA proteins in the plasma with specific association of the SAA with HDL particles. The induction of SAA proteins was comparable to that seen in mice presented with the inflammatory agent, bacterial lipopolysaccharide (LPS). Adenoviral induced SAA levels were maintained for up to several weeks without a significant decrease in SAA expression. Injection of rats with the mouse SAA1.1 adenoviral vector, followed by amyloid enhancing factor (AEF) and silver nitrate resulted in the deposition of amyloid fibrils in the spleen. After 2 weeks, amyloid could be detected in other tissues, including the heart, liver, kidneys and lungs. When animals were injected with null or the SAA2.2 virus no amyloid was detected. These studies demonstrate that the inability of the rat to develop AA amyloid is due to the lack of synthesizing an amyloidogenic SAA protein. Furthermore, the expression of the adenoviral SAA protein from the liver and incorporation onto HDL particles further supports the hypothesis that AA amyloid is derived from circulating SAA protein. The ease of use of the adenoviral vectors and the rat provide an excellent model to study the function of SAA proteins.

Adenoviridae↗

PubMed2000

[Loss of imprinting of insulin-like growth factor II gene in acute myeloid leukemia].

OBJECTIVE: To investigate the status of insulin- like growth factor-2(IGF-2) gene imprinting in acute myeloid leukemia(AML). METHODS: Selection of heterozygous cases for Apa I polymorphism within exon 9 of IGF-2 gene and further analysis of loss of imprinting(LOI) were done in 26 AML patients by polymerase chain reaction(PCR), reverse transcription PCR (RT-PCR) and restriction fragment length polymorphism(RFLP) technique. RESULTS: Eleven cases of AML patients were identified as heterozygous for IGF-2(11/26); 8 heterozygous patients showed biallelic expression of IGF-2, indicating loss of IGF-2 imprinting. CONCLUSION: The frequent LOI of IGF-2 may play a role in the development of acute myeloid leukemia.

Adolescent↗

PubMed2000

[Effects of heparin on the growth, extracellular matrix and matrix metalloproteinase gene expression in rat hepatic stellate cells].

OBJECTIVE: To study the effects of heparin on the growth, extracellular matrix and matrix metalloproteinase (MMP) gene expression in rat hepatic stellate cells (HSC). METHODS: Activated HSC was treated by heparin or fetal calf serum without heparin. The cell growth was evaluated by actual cell count and BrdU-labelled immunocytochemical stain. The gene expressions of type I and IV procollagen, fibronectin, MMP-2 and membrane type matrix metalloproteinase (MT-MMP) were investigated by immunocytochemical stain and digoxigenin-labeled in situ hybridization technique, respectively. In addition, the gelatinase activity of MMP-2 was examined by zymography. RESULTS: Heparin could obviously reduce HSC growth, inhibit the synthesis of type I procollagen and fibronectin protein, and the gene expressions of type I procollagen, fibronectin and MT-MMP. The expressions of type IV procollagen, MMP-2 and MMP-2 activity were not affected by heparin. CONCLUSION: The results demonstrate that heparin can inhibit HSC proliferation, down-regulate interstitial collagen synthesis and inhibit MT-MMP gene expression.

Animals↗

PubMed2000

[Research on renaturation of recombinant human pro-urokinase expressed from Escherichia coli].

Recombinant human pro-urokinase forms insoluble inclusion body when overexpressed in Escherichia coli, and it must be denatured and renatured in vitro before it acquires activity. This study aimed to increase the renaturation yield of denatured pro-urokinase. We have evaluated the basic renaturation conditions of pro-urokinase through qualitative and quantitative analysis of pH, temperature, denaturant concentration, protein concentration, the ratio of reduced and oxidized thiol reagents. The effects of nonspecific additives, step-wise dilution and urea gradient dialysis have been also compared. The optimal conditions of pro-urokinase renaturation with the yield about 20%-30% have been obtained.

Dithiothreitol↗

PubMed2000

Changes of transforming growth factor beta 1 in rat periodontal tissue during orthodontic tooth movement.

OBJECTIVE: To investigate the distribution and change of transforming growth factor beta 1 (TGF-beta 1) in rat periodontal tissue and understand the role of TGF-beta 1 in orthodontic tooth movement. METHODS: Force was applied on right maxillary first molars in rats, followed by the examination of the decalcified alveolodental connected tissue in different stages of tooth movement. An immunohistochemical staining technique (SP method) was used for this examination. RESULTS: TGF-beta 1 exists in normal periodontal tissue. The expression of it in periodontium increases during orthodontic tooth movement. From 5 to 10 days after applying force, the expression at the tension site was significantly greater than that at the pressure site. CONCLUSIONS: Changes in TGF-beta 1 levels play an important role in the remodeling of periodontal tissue during orthodontic tooth movement, and can powerfully promote bone formation.

Alveolar Process↗

PubMed2000

[Detection of Coxsackie B virus IgM antibody in myocarditis patients by Mac ELISA].

OBJECTIVE: To detect Coxsackie B virus type 1-6 IgM antibodies from 193 clinically diagnosed myocarditis cases. METHODS: The capture IgM ELISA (Mac ELISA) test was used. RESULTS: The total positive rate of Coxsackie virus B 1-6 IgM antibody in myocarditis patients was 69.6% (135 cases), among which Cox B3 type was as high as 40% (54 cases) of the total positive patients. The others were 29.6% (40 cases), 18.5% (25 cases), 7.4%(10 cases), 3.0% (4 cases), 1.5% (2 cases) of Cox B2, Cox B4, Cox B1, Cox B5 and Cox B6 respectively. Meanwhile only 20.4% (37 cases) Cox B IgM positive cases could be detected in 181 non-myocarditis patients of same ages. The results showed that the positive rate of Cox B virus IgM antibody in clinically diagnosed myocarditis was significantly higher than that in control group (P <0.01). CONCLUSIONS: The Cox B viruses may be the main agents causing viral myocarditis in Beijing cases. Mac ELISA is an easy, rapid, specific and sensitive method to detect Cox B virus IgM antibody for early and rapid diagnosis of myocarditis.

Antibodies, Viral↗

PubMed2000

Expression of fibronectin receptor, integrin alpha 5 beta 1 of hepatic stellate cells in rat liver fibrosis.

OBJECTIVE: To investigate the role of fibronectin (FN) receptor alpha 5 beta 1 in liver fibrosis. METHODS: Northern blot analysis and immunohistochemical techniques were used to observe changes in the expression of FN and FN receptor alpha 5 beta 1 on hepatic stellate cells (HSCs) in vivo and in vitro of rat liver fibrosis induced by CCl4. RESULTS: (1) alpha 5 beta 1 was mainly detected in the endothelia and some of the desmin(DM) positive cells of the sinusoids in normal rat liver. The expression of alpha 5 beta 1 of DM positive cells detected by immunohistochemistry reached its peak at the 10th week of the experiment. The changes in FN expression were similar to that of alpha 5 beta 1. (2) The expression of FN, alpha 5 and beta 1 mRNAs in the experimental group was remarkably increased especially at the 6th week, compared to that of normal liver specimens. The expression of the three mRNAs of HSCs in vitro isolated from the experimental group (6 weeks) was higher than those from normal liver. (3) The expression of FN, alpha 5 and beta 1 mRNAs increased in normal rat HSCs after treatment with transforming growth factor-beta 1 (TGF-beta 1) for 2 hours. After 4 hours of treatment, the expression of the three mRNAs fell to levels similar to the control group. Immunocytochemistry revealed that the expression of alpha 5 beta 1 of HSCs reached its peak after 4 hours of treatment with TGF-beta 1 and dropped to normal 2 hours later. CONCLUSION: These data suggest that HSCs normally express FN receptor alpha 5 beta 1. The activation of HSCs during liver fibrogenesis leads to an increase of FN, alpha 5 and beta 1 mRNA expression. The expression of FN and alpha 5 beta 1 of HSCs in vitro is up-regulated by TFG-alpha 5 beta 1. The detection of gene transcription of FN and its receptor by Northern blot analysis suggests the activation and proliferation of HSCs and thereby provides a sensitive signal of liver fibrosis.

Animals↗

PubMed2000

[Value of fractional curettage of prehysterectomy in endometrial neoplasms].

OBJECTIVE: To evaluate the value of fractional curettage in the histologic type, histologic grade and cervical involvement of the endometrial carcinoma. METHODS: A total of 691 cases of endometrial carcinoma in fractional curettage specimen were analyzed retrospectively, patients with no carcinoma postoperatively in the removed uterus were excluded from the study. Those endocervical curettages with adenocarcinoma according the histologic relationship between tumor tissue and endocervical tissue were divided into 4 main groups. RESULTS: (1) The inaccurate rate of histologic type in prehysterectomy curettage was 8.83% (61/691). About a half poorly differentiated adenocarcinomas were undergraded in the prehysterectomy curettage. (2) In 691 cases of endometrial carcinomas, 159 (23.01%) cases were determinated cervical involvement by tumor in the hysterectomy specimen, of which 88 cases had tumor tissue in the prehysterectomic curettage. In a variety of histologic appearances of endocervical curettage, the ratio of cervical involvement by tumor in hysterectomy was respectively group I 30.30% (10/33), group II 9 cases (9/9), group III 100.00% (40/40), group IV 46.88% (29/63), those without tumor tissue in the endocervical curettage 12.68% (71/560). CONCLUSIONS: (1) The reliability of histologic type of endometrial carcinoma based on the findings of the fractional curettage specimen in related to the tumor type. The diagnosis of poorly differentiated adenocarcinomas in the prehysterectomy specimen is limited. (2) Determinating the presence or absence of cervical involvement can't only depend upon the endocervical curettage with or without tumor tissue. It is suggested that those endocervical curettage with tumor tissue be divided into 4 main groups according the histologic relationship between tumor tissue and endocervical tissue, group II and group III are good predictors of cervical involvement by tumor.

Cervix Uteri↗

PubMed2000

Reactive oxygen species contribute to the induction of superoxide dismutase during heat shock in cultured rat neonatal cardiomyocytes.

OBJECTIVE: To explore the influence of reactive oxygen species (ROS) during heat shock on the activity of superoxide dismutase (SOD) and the endurance of cardiomyocytes against hypoxia-reoxygenation damage. METHODS: Cultured rat neonatal cardiomyocytes were divided into 5 groups (n = 6/group): normal control, anoxic control, heat shock, heat shock + SOD (150 U/ml) and exogenous ROS pretreated. Myocytes were first incubated in a CO2 incubator (37 degrees C) with Hank's solution for 30 min, followed by specific pretreatment. Heat shock was performed by incubating the cells in a 43 degrees C incubator for 30 min; exogenous ROS were generated by the reaction of xanthine oxidase with xanthine. After the dishes were returned to normal incubation conditions for 24 h, myocytes underwent hypoxia (3 h) and reoxygenation (1 h). RESULTS: Compared with control groups, ROS production increased after the cells experienced heat shock (1.28 +/- 0.34 nmol/mg.1 protein vs 0.80 +/- 0.23 nmol/mg.protein and 0.74 +/- 0.20 nmol/mg.protein, P < 0.05) or ROS pretreatment (3.30 +/- 0.58 nmol/mg.protein, P < 0.05). 24 hours later, accompanied by attenuated cellular injury, significantly increased SOD activity was found in heat shock (2.55 +/- 0.43 U/mg.protein vs 0.77 +/- 0.12 U/mg.protein and 0.63 +/- 0.09 U/mg.protein, P < 0.05) and exogenous ROS pretreated (2.34 +/- 0.31 U/mg.protein, P < 0.05) groups following reoxygenation. Moreover, opposite results were found when myocytes were treated with SOD during heat shock. CONCLUSIONS: The release of ROS during heat shock triggers delayed myocardial protection by altering the activity of SOD. ROS may play an important pathophysiological role in heat shock induced myocardial protection.

Animals↗

PubMed2000

[Serum leptin levels during pregnancy].

OBJECTIVE: To study the serum leptin levels in Chinese pregnant women, and to discuss the relationship between leptin level and pregnancy. METHODS: Serum leptin concentrations of 251 pregnant women (13.6 to 30.9 gestational weeks) were measured with radioimmunoassay, and 35 age and body mass index (BMI) matched non-pregnant women were selected as control. Serum leptin concentrations were compared between pregnant and control women, correlations between leptin concentrations and gestational age, weight, BMI, blood pressure and other parameters were analyzed. RESULTS: In these pregnant women, aged (28.5 +/- 3.9) years, BMI (23.6 +/- 2.8) kg/m2, serum leptin concentrations were (15.1 +/- 7.4) micrograms/L; while in control women, aged (27.4 +/- 3.8) years, BMI (22.6 +/- 2.5) kg/m2, serum leptin concentrations were (9.1 +/- 4.9) micrograms/L. The mean age and BMI are comparable between 2 groups. Serum leptin concentrations in pregnant women were much higher than those in control women (P < 0.001). Within the pregnant women, serum leptin concentrations were significantly correlated to body weight(r = 0.529), BMI (r = 0.551,), waist circumference (r = 0.564), height of uterus bottom (r = 0.151), systolic blood pressure (r = 0.134) and diastolic blood pressure (r = 0.251). During pregnancy, serum leptin concentrations rose along with the gestational age, although no statistical difference was revealed up to 30th gestational week. CONCLUSIONS: Leptin is a hormone intimately related to the pregnancy, its concentrations are much higher during pregnancy than those of non-pregnant women with matched age and BMI. Like in non-pregnant women, leptin levels are significantly correlated to body weight and BMI, and also correlated to blood pressure, the correlation between leptin and diastolic blood pressure is more evident, indicating that serum leptin may serve as a marker for detecting and monitoring pregnancy complications.

Adult↗

PubMed2000

[The expression of multiple drug resistance associated genes in ovarian cancer].

OBJECTIVE: The aim of the investigation was to find out the relationship between the expression of multidrug resistance gene (MDR1), multidrug resistance protein (MRP), lung resistance protein (LRP) and glutathione S-transferase pi (GST-pi) with the clinical pathological characteristics and the prognosis in the ovarian cancer patients who never received chemotherapy before operation. METHODS: The expression of MDR1, MRP, LRP and GST-pi in 41 cases of ovarian cancer, 25 cases of benign ovarian tumor and 12 normal ovary tissue were investigated by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In normal ovary, benign tumor and ovarian cancer, the positive expression of MDR1 was 0.0%, 0.0% and 29.3%, the positive of MRP was 16.7%, 12.0% and 53.7%, the positive of LRP was 25.0%, 52.0% and 87.8%, the positive of GST-pi was 8.3%, 12.0% and 51.2% respectively. The ratios of co-expression of multiple genes in ovarian cancer were much higher than that in benign ovarian tumor. All tested genes showed no significant relationship to the clinical stage, histological type and the differentiation of the tumor except that the expression of MDR1 and MRP was closely related to the differentiation (P < 0.05). The non-responders to platinum or taxol based combination chemotherapy exhibited higher ratios of MDR1 and MRP expression than the responders (P < 0.05). Furthermore, the co-expression phenomenon was more common in non-responders. CONCLUSIONS: Multiple gene expression is involved in drug resistance in ovarian cancer. The co-expression of MDR1, MRP, LRP and GST-pi is higher in ovarian cancer than that in benign ovarian tumor and normal ovary tissue. The expression of MDR1 and MRP is closely related to the tumor differentiation and the response to chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2000

[The contribution of phacoemulsification to combined cataract and glaucoma surgery].

OBJECTIVE: To study the safety and effectiveness of phacoemulsification (phaco) in trabeculectomy combined with cataract extraction (phacotrabeculectomy) and posterior chamber intraocular lens (IOL) implantation. METHODS: 68 eyes with glaucoma and cataract were randomly divided into two groups: the phacotrabeculectomy with IOL implantation and modern extracapsular cataract extraction (ECCE), trabeculectomy and IOL implantation. RESULTS: Postoperatively, in the phaco group, the intraocular pressure (IOP) decreased obviously at the early stage (P < 0.05), the number of cases necessary for the use of anti-glaucoma drug was decreased, the mean kinds of the drug applied were markedly decreased (P < 0.05), the visual acuity improved quickly, significantly and steadily, and the complications were less than that in the ECCE group. CONCLUSIONS: The phaco's triple surgery is safe and effective. In cases with glaucoma and cataract, the surgery is indicated even when the cataract is not mature or premature.

Aged↗

PubMed2000

[Analysis for the titer of plasma antibody to heat stress protein 70 in workers exposed to benzene].

OBJECTIVE: To explore the titer of plasma antibody against heat stress protein 70 (HSP70) in workers exposed to benzene and its possible relationship to their health. METHODS: Forty-two workers exposed to more than 40 mg/m(3) of benzene were selected as a high exposure group, 50 of workers exposed to less than 40 mg/m(3) as a low exposure group, and 42 unexposed as a control group. Their plasma antibody against HSP70 was determined with enzyme-linked immunosorbent assay (ELISA). Analysis was conducted to study the relationship between it and other factors. RESULTS: Proportion of plasma positive antibody to HSP70 with a titer of 1:20 was significantly higher in high exposure group (26.2%) than that in controls (9.5%). Moreover, prevalence of adverse symptoms and positive signs, and level of lipid peroxide were all significantly higher in high exposure group with positive antibody to HSP70 than those with negative antibody. CONCLUSION: It was concluded that the titer of plasma antibody to HSP70 had close relation with the health of workers exposed to benzene.

Adult↗