Pathological changes of major organs after rats inhaled methyl ethyl ketone peroxide aerosol / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the pathological changes of major organs in rats that have inhaled methyl ethyl ketone peroxide (MEKP) aerosol and to provide clues to the oxidative damage mechanism of MEKP.</p><p><b>METHODS</b>A total of 100 Sprague-Dawley rats (male-to-female ratio = 1:1) were randomly and equally divided into blank control group, solvent control group, and 50, 500, and 1000 mg/m(3) MEKP exposure groups to inhale clean air, solvent aerosol, or MEKP for 6 h per day, 5 d per week, for 13 weeks. A rat model of subchronic MEKP exposure was established. The clinical manifestations during exposure were recorded. The organ coefficients of the kidney, thymus, and testis were calculated. The histopathological changes of the lung, liver, and testis were observed by HE staining.</p><p><b>RESULTS</b>The male rats in 1000 mg/m(3) MEKP exposure group had significantly lower organ coefficients of the kidney and testis than those in blank control group, solvent control group, and 50 and 500 mg/m(3) MEKP exposure groups (P < 0.05). The rats in 1000 mg/m(3) MEKP exposure group had a significantly lower organ coefficient of the thymus than those in blank control group and solvent control group (P < 0.05). Some rats in 500 and 1000 mg/m3 MEKP exposure groups had significant damage to the lung, liver, and testis, which demonstrated a worsening trend as the dose increased. Pulmonary hyperinflation, hyperemia, bleeding, interstitial pneumonia, and even lung abscess were seen in the damaged lung. Nuclear enrichment, hepatocyte steatosis, and mild cellular edema in the portal area were seen in the damaged liver. Variable degeneration, necrosis, and dysplasia of spermatogenic cells and significant decrease in sperms in spermatogenic cells were seen in the damaged testis. The female rats in blank control group, solvent control group, and 50, 500, and 1000 mg/m(3) MEKP exposure groups showed no pathological changes in the ovary.</p><p><b>CONCLUSION</b>Inhalation of MEKP aerosol can cause oxidative damage to the liver, lung, kidney, thymus, and testis in rats, particularly to the testis in male rats.</p>

Comparison study on knee osteoarthritis in rabbits induced by different concentrations of papain / 中国骨伤

<p><b>OBJECTIVE</b>To compare the knee osteoarthritis (OA) models in rabbits by different concentrations of papain and provide data for exploring pathogenesis and treatments of this disease.</p><p><b>METHODS</b>Sixty New Zealand white rabbits were randomly divided into four groups of 15 each and given injections into the right knee on days 1, 3 and 5 including intra-articular injections of 2%, 5% or 10% (w/v) papain and 0.03 mol/L L-cysteine at the dose of 0.1 ml/kg (experimental groups). The 0.9% NaCl (w/v) with a dose of 0.1 ml/kg were injected intra-articularly into the right knees of rabbits in the control group. The rabbits were sacrificed at 2, 4, 6 weeks respectively after the initiation of papain injection and these OA models were evaluated through recording the width of knee joint, performing the morphological observation and histological evaluation of articular cartilage and synovium.</p><p><b>RESULTS</b>The degenerative changes were demonstrated in knee joints of rabbit in all experimental groups, such as thinner articular cartilage, fibrillation and destroyed cartilage matrix, and inflammation, proliferation, and degeneration of the synovial tissue. All these changes were much worse with increased concentration and prolonged observation time.</p><p><b>CONCLUSION</b>Different severity of OA are established through intra-articular injections of 2%, 5% or 10% papain and 0.03 mol/L L-cysteine at the dose of 0.1 ml/kg. These models are of the characters of short period and a good reproducibility.</p>

Effects of lead on protein kinase C expression in U251 cell line / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of lead on mRNA and protein expression of PKC in U251 cell line.</p><p><b>METHODS</b>After U251 cells were exposed to 0.05, 0.50, 5.00, 50.00, 500.00, 900.00 and 1000.00 micromol/L Ph(Ac)2 for 24 hours, the cytotoxicity of Pb on U251 cells was measured by MTT assay. RT-PCR and Western blot assay were used to detect the mRNA and protein expression levels of PKC in U251 cells exposed to 0.05, 5.00 and 500.00 micromol/L Ph (Ac), for 24 hours.</p><p><b>RESULTS</b>The survival rates of U251 cells treated with 5.00, 50.00, 500.00, 900.00 and 1000.00 micromol/L Pb (Ac)2 were 84.5%, 78.2%, 76.5%, 50.3% and 43.2%, respectively, which were significantly lower than those of control group (P < 0.01). The PKC mRNA expression level (0.40 +/- 0.01) of U251 cells treated with 500.00 micromol/L Pb (Ac)2 was significantly lower than that (0.51 +/- 0.02) of control group (P < 0.01). The PKC protein expression levels of U251 cells treated with 0.05, 5.00 or 500.00 micromol/L Pb(Ac)2 were 0.68 +/- 0.02, 0.62 +/- 0.01 and 0.33 +/- 0.02, respectively, which were significantly lower (0.98 +/- 0.01) than those of control group (P < 0.01).</p><p><b>CONCLUSION</b>Lead can decline the cell viability, PKC mRNA and protein expression levels of U251 cells.</p>

Effects of lead exposure on acid-sensing ion channel in hippocampus of baby-rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effects of chronic lead exposure on mRNA and protein expression of ASIC1a, ASIC2a, ASIC2b in hippocampus of baby-rats.</p><p><b>METHODS</b>The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water or lead contained water (0.2% and 1.0% lead acetate) respectively, 5 rats in each group. The lead-exposure ranged from the 0 day of pregnancy to the offspring weaned. Then the baby-rats were fed with lead water like their mothers and killed at postnatal day 8 or 50. Atomic absorption spectrometry was used to determine lead content in the brain. RT-PCR and Western blotting were used to observe mRNA and protein expression of ASIC1a, ASIC2a and ASIC2b in their hippocampus respectively.</p><p><b>RESULTS</b>The brain lead content of test groups was higher than that of the control group (P < 0.01), and the lead content of the postnatal day 50 was higher than that in postnatal day 8 (P < 0.01). Compared with the control group, ASIC1a mRNA expression of 1.0% lead exposure in the hippocampus was uptrend (P < 0.01), ASIC1a protein expression of each test group was downtrend (P < 0.05), while for ASIC2a and ASIC2b mRNA and protein, there was no significant differences observed (P > 0.05).</p><p><b>CONCLUSION</b>ASIC1a expression in hippocampus can be changed by chronic lead exposure.</p>

Effects of lead exposure on protein kinase C and calmodulin expression in hippocampus of baby-rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effect of chronic lead contaminant on protein expression of protein kinase (PKC) and calmodulin (CaM) in hippocampus of baby-rats.</p><p><b>METHODS</b>The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water and lead-contained water (0.2% and 1.0% lead acetate) respectively. The lead exposure period ranged from the 0 day of pregnancy to the offspring weaned. Then the baby-rats were fed with lead water the same as their mothers. Pups were killed at postnatal day 8 and 50 respectively. Atomic absorption spectrometry was used to determine lead content of rats' brain. Western-blotting was used to observe protein expression of PKC and CaM in hippocampus of baby-rats.</p><p><b>RESULTS</b>The brain lead content of test groups was much higher than that of the control group in the same growth period (P < 0.01). The content of brain lead in rats of postnatal day 50 was significantly higher than that of rats of postnatal day 8 (P < 0.01). Compared with control group, PKC and CaM protein expressions of chronic lead exposure baby-rats in the hippocampus were down trend (P < 0.05).</p><p><b>CONCLUSION</b>The decrease of PKC and CaM protein expression level in hippocampus might be one of the molecular mechanisms of lead induced impairment of learning and memory.</p>

Effects of lead exposure on protein kinase C and calmodulin expression in hippocampus and neurobehavioral function of baby rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the effect of chronic lead contaminant on mRNA expression of protein kinase C (PKC) and calmodulin (CaM) in hippocampus of baby rats.</p><p><b>METHODS</b>The Wistar pregnant rats were randomly divided into 3 groups fed with distilled water and lead contained water (0.2% and 1.0% lead acetate) respectively. The lead exposure period was from the 0 day of pregnancy to the day when the offspring weaned. Then the baby rats were fed with lead water the same as their mothers. The cliff avoidance reflex within postnatal day 8 and step down test at postnatal day 50 were performed. Then pups were killed at postnatal day 8 and 50 respectively. Atomic absorption spectrometry was used to determine lead content of rats' brain. RT-PCR was used to observe mRNA expression of PKC and CaM in hippocampus of baby rats.</p><p><b>RESULTS</b>The brain lead content of test groups were much higher than that of the control group. The completion rate of cliff avoidance reflex and the score of step down test of test groups were lower than those in the control group (P < 0.05). Compared with control group, PKC and CaM mRNA expression of chronic lead exposure baby rats in the hippocampus had the down trend (P < 0.05).</p><p><b>CONCLUSION</b>The decrease of PKC and CaM mRNA expression level in hippocampus has a great link with the impairment of learning and memory induced by lead in baby rats, which might be one of the molecule mechanisms of lead induced impairment of learning and memory.</p>

Construction of anti-lung tumor gene differentially expressed bank of wild mouse / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To construct the anti-lung tumor gene differentially expressed bank of wild mouse and to explore the mechanisms of the TW wild mouse suppressing the occurring of lung tumor.</p><p><b>METHODS</b>Using suppression subtractive hybridization (SSH) technique, the differentially expressed genes between TAF1 mouse and A/wy mouse were selected out and the subtracted cDNA bank was constructed. 166 clones were performed DNA sequencing and then were assayed by blast programme.</p><p><b>RESULTS</b>Among the blast results of 166 differentially expressed clones, 87 known genes (mRNA or cDNA) were in homology with 134 clones and were divided into 7 classifications according to the biological role.14 DNA fragments were in homology with 32 clones, in which 20 clones were in homology with 9 mouse DNA sequences, 2 clones were in homology with one bacterial gene sequences and 3 clones were clone vector.</p><p><b>CONCLUSION</b>With SSH technique, the anti-lung tumor gene differentially expressed bank of wild mouse are successfully constructed.</p>

Clinical and angiographic follow-up study of sirolimus-eluting stent for treatment of in-stent restenosis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the effectiveness and safety of sirolimus-eluting stents (SESs) for treatment of in-stent restenosis (ISR).</p><p><b>METHODS</b>All 27 patients with ISR and clinical evidence of ischemia had been treated with SESs. Among them, 23 patients had diffuse and complex lesions, and 5 of them received 2 SESs. Clinical and angiographic follow-up were performed for all patients and the results were analyzed.</p><p><b>RESULTS</b>All stents were implanted successfully. There were no remained stenosis and major in-hospital complications. Average follow-up time was 8.9 +/- 2.1 (5-14) months, with a clinical follow-up rate of 96.3% and angiographic follow-up rate of 92.6%. During the follow-up, there was none of death. One patient had recurrent angina with an angiographic evidence of the proximal edge restenosis of the stent. Mild neointimal hyperplasia in the proximal edge was found in 2 patients, but the stenosis was less than 25%. No late lumen loss was found in other 24 patients. The late lumen loss of the in-stent averaged 0.09 +/- 0.02 mm, and of the distal edge vessel averaged 0.10 +/- 0.03 mm, and of the proximal edge vessel averaged 0.20 +/- 0.06 mm. The rate of target vessel revascularization was 3.8%.</p><p><b>CONCLUSION</b>The SES implantation is safe and feasible for the treatment of in-stent restenosis, which could effectively prevent neointimal hyperplasia and recurrent restenosis of the lesion.</p>