Establishment of a rat model of mycoplasma pneumonia and the treatment / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a rat model of mycoplasma pneumonia (MP) for investigating the pathogenesis of MP and its therapy with drugs.</p><p><b>METHODS</b>Thirty Wistar rats were randomly divided into 6 groups (n=5), including a control group, a MP model group, a erythromycin lactobionate group and 3 erythromycin microspheres groups (high, middle, and low dose groups). With the exception of those in the control group, all the rats received intranasal MP administration followed by corresponding treatments administered via tail vein injection. At different time points after inoculation of the pathogen, the lungs of the rats were taken for histopathological scoring.</p><p><b>RESULTS</b>In the MP model group, the lung pathology was characterized by patchy interstitial pneumonitis with predominantly lymphocyte infiltration and mucosal edema. The bronchiolar walls became thickened and the lumens narrowed. In erythromycin lactobionate and erythromycin microspheres treatment (high and middle dose) groups, clear cell boundaries were observed in the lungs where no obvious pathological changes were found. RT-PCR amplification showed positive results of MP RNA in the model group, erythromycin lactobionate group and erythromycin microsphere groups.</p><p><b>CONCLUSION</b>The approach described is practicable to establish rat models of MP. Erythromycin microspheres can effectively relieve the lung inflammations and has therapeutic effect on MP.</p>

Chronic toxicity of 97% isopropyl thioxanthone in rat by oral administration for 2 years / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the oral chronic toxicity of 97% isopropyl thioxanthone (97% ITX) in rats, determine the no-observed adverse effect levels (NOAEL).</p><p><b>METHODS</b>Four groups of rats were fed with foodstuff containing 97% ITX in the dosage of 1000.0, 250.0, 62.5 mg/kg respectively for 2 years. The general behavior, body weight, food availability ect. were observed during the experiment. At the end of the experiment, blood and urine samples were collected for routine and biochemical assays. The internal organs were taken for calculating their organ coefficients and histopathological examinations.</p><p><b>RESULTS</b>During the experimental period, no obvious abnormality were found in the experimental animals. The body weight and the total food availability rate in the high dosage group of male were lower than that of control (P < 0.05). Hematology examination showed that the quantity of Hb and RBC in high dosage groups of both the male and female and Hb in the male middle group were all lower than the control group (P < 0.01 or P < 0.05). Analysis of correlation indicated that r = -0.433, P < 0.01 in male, r = -0.337, P < 0.01 in female of Hb; r = -0.266, P < 0.05 in male, r = -0.317, P < 0.01 in female of RBC. There were obviously negative correlation. Serum biochemistry examination showed the concentration of CHO in the high and middle dosage treated rats of male and female were higher than that of the control (P < 0.01 or P < 0.05). Analysis of correlation indicated that r = 0.497, P < 0.01 in male, r = 0.417, P < 0.01 in female. No abnormality were found in urine examination. The organ weight and organ coefficient such as liver, were higher than control group (P < 0.01). The result of histopathological examinations displayed that the renal tubule Cast and the tubulointerstitial nephritis in the treated groups were higher than that of control group (P < 0.01).</p><p><b>CONCLUSION</b>97% ITX could obviously interfere with the animals' physical condition, and reduce the number of RBC and the concentration of Hb in the blood, interact metabolism of lipoid and induce the concentration of CHO in the serum. The livers of the treated rats are compensatory enlarged. And kidneys of the poisoning animals are damaged. The 2 years oral NOAEL of 97% ITX in rats are more than 4.63 mg/kg for female rats, and larger than 4.06 mg/kg for male rats.</p>

Antimicrobial effects of erythromycin microspheres against Mycoplasma Pneumoniae in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the antimicrobial effects of erythromycin microspheres against Mycoplasma pneumoniae in rats.</p><p><b>METHODS</b>With erythromycin lactobionate as the positive control, erythromycin microspheres at 3 non-toxic doses (0.1, 0.5, and 1.2 g.kg(-1).d(-1)) were administered intragastrically for 6 consecutive days in Wistar rats with Mycoplasma pneumoniae infection. The general condition and lung index of the rats were observed and measured to assess the therapeutic effects of the treatments against Mycoplasma pneumoniae infection.</p><p><b>RESULTS</b>The erythromycin microspheres at 0.1, 0.5, 1.2 g.kg(-1).d(-1) significantly alleviated the symptoms of the rats infected with Mycoplasma pneumoniae and reduced the pulmonary index of the infected rats from 1.75 to 1.45, 1.38 and 1.25, respectively (P < 0.01). An obvious dosage-effect relationship was noted between the dose of erythromycin microsphere and the tissue pathologies due to the infection.</p><p><b>CONCLUSION</b>Erythromycin microspheres possess strong activity against Mycoplasma pneumoniae in rats.</p>

Rapid detection of oxacillin and erythromycin resistance genes in Staphylococcus aureus using multiplex PCR / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a rapid multiplex PCR (MPCR) detection system of oxacillin and erythromycin resistance genes in Staphylococcus aureus (S. aureus) and evaluate the genotype distribution of the genes associated to mecA, ermA and ermC resistance in Guangzhou.</p><p><b>METHODS</b>The S. aureus strains were identified and susceptibility tests were performed using VITEK-60 or PHOENIX-100 system. The inducible resistance to clindamycin of strains with of erythromycin resistance was conducted using D-test, and the MPCR system of for detecting the antibiotic resistance genes was optimized.</p><p><b>RESULTS</b>The MPCR assay for detecting the resistance genes was constructed successfully. According to the results of MPCR, the positivity rates for mecA, ermA and ermC genes among the 124 strains of S. aureus isolated from clinical samples were 56.5%, 50% and 33.9%, respectively. Good correlation was observed between the antibiotic resistance phenotypes and the S. aureus genotypes. mecA were detected in all the methicillin-resistant S. aureus strains, and ermA and/or ermC in 97.7% of the S. aureus strains with erythromycin resistance.</p><p><b>CONCLUSION</b>This MPCR system allows rapid and reliable analysis of antibiotic resistance genotypes of S. aureus isolated from clinical samples. mecA, ermA, and ermC genes are among the predominant genetic determinants for the resistance to oxacillin and erythromycin in S. aureus isolates in Guangzhou.</p>

Identification and tissue localization of intermediate filament protein in Angiostrongylus cantonensis / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify the type of the intermediate filament (IF) protein of Angiostrongylus cantonensis and analyze its tissue localization.</p><p><b>METHODS</b>Recombinant pET-IF of antigen IF was expressed in E.coli with IPTG induction, and the expression products were purified by His.Bind column and identified for determining the type of the IF protein by Western blotting. Anti-IF antibody was prepared by multi-spot subcutaneous injection into mouse and used to detect the tissue slices of A. cantonensis by immunohistochemical analysis.</p><p><b>RESULTS</b>The antigen IF were correctly expressed and purified, and identified as a keratin located in the intestine wall and cytoplusma.</p><p><b>CONCLUSION</b>The antigen IF is distributed in the intestine wall of A. cantonensis.</p>

Induced differentiation and signaling factor PTEN expression of 3T3-L1 adipocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To optimize the condition for inducing the differentiation of 3T3-L1 preadipocytes into adipocytes and study the expression of PTEN tumor suppression gene in this process, aiming to understand the regulatory role of PTEN in normal adipocyte differentiation and collect laboratory evidence for developing drugs targeting PTEN.</p><p><b>METHODS</b>The differentiation of 3T3-L1 preadipocytes cultured in high-glucose DMEM were induced according to 2 protocols with different combinations of dexamethasone, isobutylmethylxanthine (IBMX) and insulin, and the resultant adipocytes were identified by oil red O staining. The total proteins of 3T3-L1 were extracted and analyzed by Western blotting, and PTEN homology between mice and human was analyzed by bioinformatic method.</p><p><b>RESULTS</b>For optimized 3T3-L1 differentiation, 3T3-L1 cells were initially induced with the combination of 1 micromol/L dexamethasone, 0.5 mmol/L IBMX and 5 microg/ml insulin for 48 h, followed by treatment with 5 microg/ml insulin in 4.5 g/L glucose DMEM for 48 h, which resulted in high differentiation rate of 3T3-L1 cells (up to 90% on the 10th day) with unified morphology and size. PTEN expression varied quantitatively in the process of differentiation, especially low on the 12th day as compared with those measured on days 4, 6 and 9. The mice PTEN mRNA shared 96% homology and PTEN amino acid 100% homology with their human counterparts.</p><p><b>CONCLUSION</b>Endogenous PTEN expression is down-regulated during 3T3-L1 differentiation, suggesting that PTEN may enhance insulin sensitivity and promote adipogenesis under physiological conditions.</p>

Effects of Alternanthera philoxeroides Griseb against respiratory syncytial virus infection in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of an oral preparation of Alternathera philoxeroides Griseb (APG) against respiratory syncytical virus (RSV) in mice.</p><p><b>METHODS</b>APG preparation was administered orally in RSV-infected mice at different daily doses (2.5, 4.5 and 6.5 g/kg) to observe the therapeutic effect of the preparation.</p><p><b>RESULTS</b>Distinct differences were observed between the death rate of the mice treated with APG at daily dose of 4.5 and 6.5 g/kg and that of the untreated mice with infection. After AGP treatment of the mice at 6.5 g/kg, the detection rate of the virus was 31.3% in the blood and 37.5% in the lung tissue, significantly lower than that in the untreated mice. The virus detection rate was 43.8% in the lung tissues of mice treated with APG at 4.5 g/kg, also significantly lower than that in the untreated control. APG treatment at the 3 doses resulted in different lung indices from that of the control.</p><p><b>CONCLUSION</b>APG may be effective for treatment of RSV infection.</p>

Nephrotoxicity of high- and low-osmolar contrast media: Protective role of fosinopril or telmisartan in a rat model / 中南大学学报(医学版)

OBJECTIVE@#To compare the nephrotoxicity of high- and low-osmolar contrast media (HOCM and LOCM), and to determine the protective role of fosinopril or telmisartan and its possible mechanism.@*METHODS@#Forty eight healthy SD rats were randomly divided into 6 groups: a normal control group, a glycerol control group, a low-osmolar contrast media (LOCM) group, a high-osmolar contrast media (HOCM) group, a fosinopril group, and a telmisartan group. Glycerine for inducing kidney damage was given to all rats except the normal control group. Twenty-four hours after the injection of glycerine, the mixed fosinopril suspension (10mg/kg) or telmisartan (5mg/kg) was poured into the stomach in the preventive group. Serum creatinine (SCr) and plasma angiotensin II (AngII) levels were detected by an automatical biochemical analyzer and radioimmunoassay; caspase-3 activity and claudin-1 expression of the renal tissue were detected by fluorometric method and immunohistochemical method. The renal injury was assessed by hematoxylin and eosin (HE) staining and terminal deoxynucleotide mediated nick and labeling (TUNEL) staining, respectively.@*RESULTS@#In diatrizoate-injected rats, SCr and AngII levels were increased (P<0.05). Expression of claudin-1 protein and caspase-3 activity in the renal tissue was upregulated. The histologic changes and percentage of apoptotic cells were milder in the LOCM rats than those in the HOCM rats. In the group pretreated with fosinopril or telmisartan, no increase in the levels of SCr and AngII was discovered. The expression of claudin-1 protein and caspase-3 activity was significantly lower than that in the HOCM group. The renal injuries induced by diatrizoate were alleviated.@*CONCLUSION@#Both HOCM and LOCM could cause cellular apoptosis in the kidney.LOCM was less toxic to rat kidney than HOCM. Nephrotoxicity induced by HOCM might be related to caspase-3, claudin-1 and AngII. Fosinopril or telmisartan may protect the renal tissue from nephrotoxicity induced by diatrizoate.

Investigation of viral pathogens contributing to habitual abortion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the association of Coxsackie B virus (CBV) with habitual abortion.</p><p><b>METHODS</b>CBV IgM antibody, viral RNA and virions were detected in 86 women with habitual abortion and 40 with induced abortion by means of enzyme-linked immunosorbent assay (ELISA), RT-PCR and virus isolation, respectively.</p><p><b>RESULTS</b>The positivity rate of CBV IgM were 87.2% and 35% in the two groups, respectively, and the detection rate of the viral RNA was 53.5% and 17.5% in blood lymphocytes, and 59.3% and 17.5% in the placentas. The virions were found in the placentas in 41.9% and 6.9% of the women, respectively. The positivity rates of CBV IgM, viral DNA and virions showed significant difference between the two groups (P<0. 01).</p><p><b>CONCLUSION</b>CBV might be one of the causes responsible for habitual abortion.</p>

Relationship analysis of urine RBC morphology between UF-100 and phase contrast microscope / 中国医师杂志

Objective To study the relationship of urine RBC morphology between UF-100 urine sediment analytic instrument andphase contrast microscope.Methods The UF-100 urine sediment analytic instrument to analyze 500 urine specimens and study the relation-ship of urine RBC morphology between urine sediment analytic instrument and phase contrast microscope.Results The according perceptionof Normocytic,Microcytic and Non-classified RBC between phase contrast microscope and UF-100 urine sediment analytic instrument RBC-info are 91.4%,94.4%,83.3% respectively,the according perception between phase contrast microscope and RBC-P70Fsc are 94.9%,95.7%,94.7% respectively,and the according perception between phase contrast microscope and RBC Fsc-DW are 84.4%,86.8%,90.5% respectively,the specificity of UF-100 and phase contrast microscope in glomerular hematuria and non-glomerular hematuria are84.3%,88.1% and 83.3%,87.9% respectively.Conclusion The results show that the UF-100 urine sediment analytic instrument issimply operating,fast and high accurate,and which can instruct clinical dignose,therapy and prognosis judgement.