[Antibacterial and residual antimicrobial activities of five final irrigants in infected root canal: an in vitro comparative study]

OBJECTIVE

To evaluate antibacterial and residual antimicrobial activities of five root canal irrigants including Qmix, MTAD(mixture of a tetracycline isomer, an acid, and a detergent), 0.2% cetrimide(CTR), 2% chlorhexidine(CHX) and 17% ethylene diaminetetraacetic acid(EDTA) and to find the most optimal final irrigants for using in root canal therapy.

METHODS

The standard enterococcus infection models were built up in 100 single rooted incisors with single canal. Totally 30 teeth were selected by using random number tablefor detecting the quality of the bacteria model. Crown-down technique with rotary ProTaper system was used to prepare the root canals. Then the teeth were randomly divided into seven groups of which five groups were irrigated with five different irrigants respectively, one group was irrigated with distilled water(distilled water group) and one group was no-irrigation group. Each tooth was sectioned into three parts: apical 1/3, middle 1/3 and coronal 1/3. After irrigation, specimenswere cultivated from day 0 to day 14. All statistical analyses were performed by means of SPSS 17.0 software. Chi-squared test was used to evaluate antibacterial activities. Generalized estimating equations was used to evaluate residual antimicrobial activities.

RESULTS

All samples rinsed with Qmix, MTAD, CTR, CHX were bacteria-free in 0 day. The samples rinsed with EDTA and distilled water had no bacteria in 7 coronal sections, 6 middle sections and 9 apical sections, respectively. The results of Qmix, MTAD, CTR and CHX groups showed significant difference when compared with that of distilled water, EDTA and control groups(P<0.05). Residual antimicrobial resultsin EDTA, distilled water, no-irrigation groups showed significant differences compared with that of Qmix, MTAD, CTR, CHX groups according to pairwise comparison(P<0.05) on day 1, 2 and 3. There was no significant difference between the other two groups(P>0.05). Antimicrobial properties on the coronal 1/3 and apical 1/3, middle 1/3 and apical 1/3 showed significant difference(P<0.05) while middle 1/3 and coronal 1/3 showed no significant difference(P>0.05).

CONCLUSIONS

Qmix, MTAD, CTR and CHX had an antimicrobial activity, but could not destroy Enterococcus faecalis completely. Antimicrobial activity in coronal 1/3 was better than in apical 1/3. Qmix, MTAD, CTR and CHX had a residual antimicrobial activity with various lasting times. The lasting time of residual antimicrobial activity was as follow: MTAD> CTR>Qmix>CHX. EDTA had no antibacterial and residual antimicrobial activities.

Expressions of Mast Cell Tryptase and Brain Natriuretic Peptide in Myocardium of Sudden Death due to Hypersensitivity and Coronary Atherosclerotic Heart Disease

OBJECTIVES

To explore the value of mast cell tryptase and brain natriuretic peptide（BNP） in the differential diagnostic of sudden death due to hypersensitivity and coronary atherosclerotic heart disease.

METHODS

Totally 30 myocardial samples were collected from the autopsy cases in the Department of Forensic Pathology, Shanxi Medical University during 2010-2015. All samples were divided into three groups： death of craniocerebral injury group, sudden death of hypersensitivity group and sudden death of coronary atherosclerotic heart disease group, 10 cases in each group. Mast cell tryptase and BNP in myocardium were detected by immunofluorescence staining and Western Blotting.

RESULTS

Immunofluorescence staining showed that the positive staining mast cell tryptase appeared in myocardium of sudden death of hypersensitivity group and coronary atherosclerotic heart disease group. Among the three groups, the expression of mast cell tryptase showed significantly differences through pairwise comparison （P<0.05）; The expression level of BNP in sudden death of coronary atherosclerotic heart disease group were significantly higher than the sudden death of hypersensitivity group and death of craniocerebral injury group （P<0.05）. The difference of the expression level of BNP between the sudden death of hypersensitivity group and the death of craniocerebral injury group had no statistical significance （P>0.05）.

CONCLUSIONS

The combined detection of the mast cell tryptase and BNP in myocardium is expected to provide help for the forensic differential diagnosis of sudden death due to hypersensitivity and coronary atherosclerotic heart disease.

Mast cell tryptase and carboxypeptidase A expression in body fluid and gastrointestinal tract associated with drug-related fatal anaphylaxis

AIM: To investigate the expression of mast cell tryptase and carboxypeptidase A in drug-related fatal anaphylaxis.

METHODS: The expression of mast cell tryptase and carboxypeptidase A in 15 autopsy cases of drug-related fatal anaphylaxis and 20 normal autopsy cases were detected. First, the expression of mast cell tryptase was determined in stomach, jejunum, lung, heart, and larynx by immunofluorescence. Different tissues were removed and fixed in paraformaldehyde solution, then paraffin sections were prepared for immunofluorescence. Using specific mast cell tryptase and carboxypeptidase A antibodies, the expression of tryptase and carboxypeptidase A in gastroenterology tract and other tissues were observed using fluorescent microscopy. The postmortem serum and pericardial fluid were collected from drug-related fatal anaphylaxis and normal autopsy cases. The level of mast cell tryptase and carboxypeptidase A in postmortem serum and pericardial fluid were measured using fluor enzyme linked immunosorbent assay (FEIA) and enzyme linked immunosorbent assay (ELISA) assay. The expression of mast cell tryptase and carboxypeptidase A was analyzed in drug-related fatal anaphylaxis cases and compared to normal autopsy cases.

RESULTS: The expression of carboxypeptidase A was less in the gastroenterology tract and other tissues from anaphylaxis-related death cadavers than normal controls. Immunofluorescence revealed that tryptase expression was significantly increased in multiple organs, especially the gastrointestinal tract, from anaphylaxis-related death cadavers compared to normal autopsy cases (46.67 ± 11.11 vs 4.88 ± 1.56 in stomach, 48.89 ± 11.02 vs 5.21 ± 1.34 in jejunum, 33.72 ± 5.76 vs 1.30 ± 1.02 in lung, 40.08 ± 7.56 vs 1.67 ± 1.03 in larynx, 7.11 ± 5.67 vs 1.10 ± 0.77 in heart, P < 0.05). Tryptase levels, as measured with FEIA, were significantly increased in both sera (43.50 ± 0.48 μg/L vs 5.40 ± 0.36 μg/L, P < 0.05) and pericardial fluid (28.64 ± 0.32 μg/L vs 4.60 ± 0.48 μg/L, P < 0.05) from the anaphylaxis group in comparison with the control group. As measured by ELISA, the concentration of carboxypeptidase A was also increased more than 2-fold in the anaphylaxis group compared to control (8.99 ± 3.91 ng/mL vs 3.25 ± 2.30 ng/mL in serum, 4.34 ± 2.41 ng/mL vs 1.43 ± 0.58 ng/mL in pericardial fluid, P < 0.05).

CONCLUSION: Detection of both mast cell tryptase and carboxypeptidase A could improve the forensic identification of drug-related fatal anaphylaxis.

Diversity and degradation mechanism of an anaerobic bacterial community treating phenolic wastewater with sulfate as an electron acceptor

Petrochemical wastewater often contains high concentrations of phenol and sulfate that must be properly treated to meet discharge standards. This study acclimated anaerobic-activated sludge to treat saline phenolic wastewater with sulfate reduction and clarified the diversity and degradation mechanism of the microbial community. The active sludge in an upflow anaerobic sludge blanket (UASB) reactor could remove 90 % of phenol and maintain the effluent concentration of SO4 (2-) below 400 mg/L. Cloning and sequencing showed that Clostridium spp. and Desulfotomaculum spp. were major phenol-degrading bacteria. Phenol was probably degraded through the carboxylation pathway and sulfate reduction catalyzed by adenosine-5'-phosphosulfate (APS) reductase and dissimilatory sulfite reductase (DSR). A real-time polymerase chain reaction (RT-PCR) showed that as phenol concentration increased, the quantities of 16S rRNA gene, dsrB, and mcrA in the sludge all decreased. The relative abundance of dsrB dropped to 12.46 %, while that of mcrA increased to 56.18 %. The change in the electron flow ratio suggested that the chemical oxygen demand (COD) was removed mainly by sulfate-reducing bacteria under a phenol concentration of 420 mg/L, whereas it was removed mainly by methanogens above 630 mg/L.

Vascular endothelial growth factor gene is associated with hypertensive cerebellar hemorrhage and rehabilitative treatment

Early rehabilitative therapy is important for patients with hypertensive cerebral hemorrhage to improve long-term function of the extremities. Vascular endothelial growth factor (VEGF) is closely associated with the pathogenesis of hypertension. To identify the markers contributing to the genetic susceptibility to hypertensive cerebellar hemorrhage (HCH) and rehabilitative treatment, we examined the potential association between HCH and 12 single nucleotide polymorphisms of the VEGF gene. Participants included 244 patients with HCH and 251 healthy controls from our rehabilitation department. The T allelic frequencies of the rs3025020 (intron 6) and rs3025039 (3'-UTR) polymorphisms were significantly higher in the patients with HCH than in the healthy controls (rs3025020 T allele: P = 0.0002, OR = 1.619, 95%CI = 1.256-2.088; rs3025039 T allele: P = 0.001, OR = 1.682, 95%CI = 1.246-2.270). Strong linkage disequilibrium was observed in three blocks (D' > 0.9), and significantly more C-G-C (rs3025020, rs3025030, and rs3025039) haplotypes (P = 0.001) were found in the controls in block 3. Significantly more T-G-C haplotypes were found in the patients with HCH (P = 0.046). Further genotype and clinical phenotype correlation study of the rs3025039 carriers showed that Fugl-Meyer and Barthel index scores were lower in the patients with the TT genotype relative to CT + CC genotypes (P < 0.01). These findings point to a role for VEGF polymorphism in HCH, and may be informative for future investigations on the pathogenesis of rehabilitative treatment.

Correlation between carbonic anhydrase IX (CA-9), XII (CA-12) and hypoxia inducible factor-2α (HIF-2α) in breast cancer

Hypoxia inducible factor 2α (HIF-2α) can trigger the expression of several genes related to many aspects of tumor progress under hypoxia. As an independent factor, the role of HIF-2α is different from other hypoxia-mediated elements, including HIF-1α. Carbonic anhydrase (CA) were also regarded as important enzymes that involve in the tumor microenvironment pH. To find clinical-pathological features of breast cancer in plateau and explore the impact of CAIX, XII (CA-9, CA-12) and HIF-2α on patients with breast cancer. Clinical data were collected and summarized in 94 patients with breast cancer. The expression of HIF-2α, CA-9 and CA-12 were detected, using immunohistochemistry of specimens. The relation between expressions and clinical-pathology was analyzed. Under normoxia, hypoxia, and after being pretreated with the JNK inhibitor SP600125, HIF- 2α, CA-9 and CA-12 expressions were detected, and adhesion and invasion assays were performed in MCF-7 cells and HIF- 2α shRNA cells, respectively. There are higher expressions of HIF-2α in tumor classification 2 and clinical stage 2 (P < 0.05). High expression of CA-12 was observed in clinical stage 2 (P < 0.05). CA-9 expression is significantly correlated with CA-12 expression (r = 0.376, P = 0.0001). HIF-2α expression is not correlated with both CA-9 expression (P = 0.21) and CA-12 expression (P = 0.27). Breast cancer cells in vitro showed that HIF-2α, CA-9 or CA-12 had an increase expression under hypoxia (1% O2). CA-9 or CA-12 expression was observed in HIF-2α shRNA cells. JNK inhibitor SP 600125 reduced the HIF-2α expression and inhibited the adhesion and invasion of breast cancer cell. Slight inhibition effect on CA-9 and CA-12 expression was found. In conclusion, HIF-2α, CA-9 and CA-12 are important hypoxia responsive elements in breast cancer. HIF-2α was involved in metastasis and invasion of breast cancer cells under hypoxia, by the involvement of c-Jun NH2-terminal kinase (JNK) signal pathway. CA-9 and CA-12 may tend to be regulated by HIF-1α more often than by HIF-2α under hypoxia.

Effects of Supplementation of β-Mannanase in Corn-soybean Meal Diets on Performance and Nutrient Digestibility in Growing Pigs

A total of 288 crossbred (Duroc×Landrace×Yorkshire) growing pigs were used in two experiments to investigate the effects of adding β-mannanase to corn-soybean meal-based diets on pig performance and apparent total tract digestibility (ATTD). Both experiments lasted 28 d and were split into two phases namely 1 to 14 days (phase 1) and 15 to 28 days (phase 2). In Exp. 1,144 pigs weighing 23.60±1.59 kg BW were assigned to one of four corn-soybean meal-based diets containing 0, 200, 400 or 600 U/kg β-mannanase. Increasing the level of β-mannanase increased weight gain (quadratic effect; p<0.01) and feed efficiency (linear and quadratic effect; p<0.01) during the second phase and the overall experiment. However, performance was unaffected (p>0.05) by treatment during phase 1. Increasing the amount of β-mannanase in the diet improved (linear and quadratic effect; p<0.05) the ATTD of CP, NDF, ADF, calcium, and phosphorus during both phases. Based on the results of Exp. 1, the optimal supplementation level was determined to be 400 U/kg and this was the level that was applied in Exp. 2. In Exp. 2, 144 pigs weighing 23.50±1.86 kg BW were fed diets containing 0 or 400 U/kg of β-mannanase and 3,250 or 3,400 kcal/kg digestible energy (DE) in a 2×2 factorial design. β-Mannanase supplementation increased (p<0.01) weight gain and feed efficiency while the higher energy content increased (p<0.01) feed intake and feed efficiency during both phases and overall. Increased energy content and β-mannanase supplementation both increased (p<0.05) the ATTD of DM, CP, NDF, ADF, phosphorus, and GE during both phases. There were no significant interactions between energy level and β-mannanase for any performance or digestibility parameter. In conclusion, the β-mannanase used in the present experiment improved the performance of growing pigs fed diets based on corn and soybean. The mechanism through which the improvements were obtained appears to be related to improvements in ATTD.

Association of HLA-DQB1*0501 with scleroderma and its clinical features in Chinese population

Specific human leukocyte antigen (HLA) DQB1 alleles confer strong susceptibility to systemic sclerosis (SSc). However, the frequencies of specific DQB1 alleles and their associations with SSc vary according to ethnicity and clinical features of SSc. The aim of this study was to profile DQB1 alleles in a Chinese population and to identify specific DQB1 alleles in association with SSc of Han Chinese. A cohort containing 213 patients with SSc and 239 gender-matched and unrelated controls was examined in the study. The HLA-DQB1 genotyping was performed with sequence-based typing (SBT) method. Exact p-values were obtained (Fisher's test) from 2x2 tables of allele counts or allele carriers and disease status. Seventeen DQB1 alleles were found in the cohort. DQB1*03:03 was the most common allele in this cohort. DQB1*05:01 was significantly increased in SSc, and was strongly associated with anti-centromere autoantibodies (ACA). Compared with SSc in other ethnic populations, SSc patients of Han Chinese are distinct in association with DQB1*06:11, common in association with DQB1*05:01, but lack association with DQB1*03:01. In addition, DQB1*06:01 appeared more common in ATA-positive Chinese SSc, and marginally associated with pulmonary fibrosis, and an increased frequency of DQB1*03:03 was observed in anti-U1RNP-positive Chinese SSc patients.

STAT4 is a genetic risk factor for systemic sclerosis in a Chinese population

Systemic sclerosis (SSc) is an immune-mediated and complex genetic disease. An association of single-nucleotide polymorphisms (SNPs) in the STAT4 gene with SSc has been reported in European Caucasians, North Americans and Japanese. We undertook the current study to examine whether the STAT4 SNPs are also associated with susceptibility to SSc and SSc subsets in a Han Chinese population. A total of 453 Han Chinese patients with SSc and 534 healthy controls were examined in the study. The SNPs rs7574865, rs10168266 and rs3821236 of the STAT4 gene were examined with SNP TaqMan assays. The T-allele carriers of rs7574865 and rs10168266 were strongly associated with the presence of anti-topoisomerase I (ATA) and pulmonary fibrosis in SSc patients, as well as with diffuse cutaneous SSc (dcSSc). The presence of anti-centromere (ACA) and limited cutaneous SSc (lcSSc) did not show significant association with any of the examined SNPs. The results were consistent with previous reports in other ethnic populations in supporting the notion that polymorphisms of STAT4 may play an important role in susceptibility to SSc. It also revealed different genetic aspects of SSc subsets in a Han Chinese population.

Marker-assisted selection in breeding silkworm strains with high silk production and resistance to the densonucleosis virus

In the silkworm (Bombyx mori), resistance to the Zhenjiang (China) strain of the densonucleosis virus (DNV-Z) is controlled by the recessive gene nsd-Z (non-susceptible to DNV-Z), which is linked to 7 simple-sequence repeat markers. Marker-assisted evaluation and selection of DNV-Z-resistant silkworms were used for predicting DNV-resistance in backcrossed animals. A silkworm race was bred using this method, and its economic characteristics were found to be similar to those of commercial silkworm races. These markers will therefore be useful for silkworm breeding programs and in screening for densonucleosis resistance in segregating populations.

Experimental study on air-stream gasification of biomass micron fuel (BMF) in a cyclone gasifier

Based on biomass micron fuel (BMF) with particle size of less than 250 microm, a cyclone gasifier concept has been considered in our laboratory for biomass gasification. The concept combines and integrates partial oxidation, fast pyrolysis, gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas. In this paper, experiments of BMF air-stream gasification were carried out by the gasifier, with energy for BMF gasification produced by partial combustion of BMF within the gasifier using a hypostoichiometric amount of air. The effects of ER (0.22-0.37) and S/B (0.15-0.59) and biomass particle size on the performances of BMF gasification and the gasification temperature were studied. Under the experimental conditions, the temperature, gas yields, LHV of the gas fuel, carbon conversion efficiency, stream decomposition and gasification efficiency varied in the range of 586-845 degrees C, 1.42-2.21 N m(3)/kg biomass, 3806-4921 kJ/m(3), 54.44%-85.45%, 37.98%-70.72%, and 36.35%-56.55%, respectively. The experimental results showed that the gasification performance was best with ER being 3.7 and S/B being 0.31 and smaller particle, as well as H(2)-content. And the BMF gasification by air and low temperature stream in the cyclone gasifier with the energy self-sufficiency is reliable.

Mammary gland expression of antibacterial peptide genes to inhibit bacterial pathogens causing mastitis

As a step toward prevention of bovine mastitis, a plasmid-mediated gene transfer technique was used to enable mammary cells to synthesize and secrete bovine lactoferricin and bovine tracheal antibacterial peptides. For this purpose, a series of mammary tissue-specific expression vectors, harboring the antibacterial peptide gene, the 5'-flanking regulation sequence of goat beta-casein, and the bovine growth hormone polyadenylation signal sequence, were constructed using a eukaryotic expression vector pIRES1-neo. The mammary gland tissue-specific expression vector carrying the antimicrobial peptide genes dissolved in physiologic saline was injected directly into the lactating mammary glands of goats. The milk samples after injection were checked by Tricine-SDS-PAGE and bacterium inhibition zone assay. The results of these tests showed that the mammary gland tissue-specific expression vector driven by the goat beta-casein gene promoter could efficiently direct the expression of antibacterial peptides in goat milk; the expression of antibacterial proteins lasted for 3 to 6 d. All of the milk samples collected from the mammary glands that had been injected with different vectors harboring the antibacterial peptide gene(s) exhibited bacteriostatic activity against different bacterial pathogens. These results demonstrated that the mammary gland tissue-specific expression vector could be used to introduce antibacterial peptide gene into the goat mammary gland, enabling secretion of a bioactive form of antibacterial peptide in the milk. This successful expression of antibacterial peptides in goat mammary glands provided a possible method to prevent mastitis in ruminants.

Overexpression of TNF-alpha and TNFRII in invasive micropapillary carcinoma of the breast: clinicopathological correlations

AIMS

Angiogenesis is essential for tumour growth and metastasis and tumour necrosis factor (TNF)-alpha is a potent angiogenic factor. Invasive micropapillary carcinoma of the breast (IMPC), a rare subtype of breast cancer, possesses a lymphotropic nature with a high incidence of lymph node metastasis and poor prognosis. The aim was to evaluate the role of TNF-alpha and its receptor TNFRII in the vascular development and metastasis of IMPC.

METHODS AND RESULTS

One hundred cases of IMPC and 97 cases of invasive ductal carcinoma, not otherwise specified (IDC) were studied in parallel by immunohistochemistry for TNF-alpha and TNFRII, and microvessel density (MVD) of the tumours was measured. The results showed that the expression of TNF-alpha and TNFRII and the MVD were higher in IMPC than in IDC (P < 0.05). In IMPC, MVD was significantly increased in those with lymph node metastasis compared with those without nodal metastasis (P = 0.001). TNF-alpha expression showed a significant positive correlation with the rate of proliferation, histological grade, lymph node metastasis and MVD (P < 0.05), whereas expression of TNFRII was correlated with TNF-alpha expression and the proliferation of tumour cells in IMPC (P < 0.05).

CONCLUSIONS

Expression of TNF-alpha and TNFRII might play an important role in the angiogenesis, tumour cell proliferation and metastasis of IMPC. These markers could represent new targets for therapeutic intervention, i.e. blocking of TNF-alpha and its signal transduction could be a promising tool for treatment.

Nanovirus-like DNA component associated with the Malvastrum yellow mosaic virus

Nanovirus-like DNA components signed DNA1 are single-stranded molecules associated with monopartite begomovirus-satellite complexes. DNA1 molecules ranging in size from 1373-1385 nucleotides were detected in 5 isolates Hn36, Hn38, Hn39, Hn44, and Hn45 of Malvastrum yellow mosaic virus (MalYMV) isolated in Hainan, China. DNA1 molecules of all isolates contained three characteristics: a single ORF, conserved hairpin structure, and A-rich region. Nucleotide sequence comparison showed that DNA1 molecules of 5 examined isolates shared high sequence identity (71.8-98.8%). In comparison with other begomovirus DNA1 and nanovirus-associated DNA, the sequence identities 59.6-76.3% and 27.2-38.4%, respectively, were found.

A simple and rapid high performance liquid chromatography method to determine levofloxacin in human plasma and its use in a bioequivalence study

A simple and rapid HPLC-UV method has been developed for determination of levofloxacin in human plasma. Chromatographic separation was performed on a Kromasil C18 column with the mobile phase consisting of acetonitrile, water, phosphoric acid and triethylamine (14:86:0.6:0.3, v/v/v/v) and flow rate was 1.0 mL/min. The method used ultraviolet detection set at a wavelength of 294 nm. The standard curves were linear over concentration range of 0.05-5.0 μg/mL (r > 0.99). The method was simple, rapid, precise, accurate and suitable for routine bioequivalence study. The method was successfully applied to the bioequivalence study of two different levofloxacin hydrochloride capsules in Chinese healthy volunteers.

SPARC, an upstream regulator of connective tissue growth factor in response to transforming growth factor beta stimulation

OBJECTIVE

To differentiate the effects of inhibition of specific small interfering RNA (siRNA) of SPARC (secreted protein, acidic and rich in cysteine) and siRNA of connective tissue growth factor (CTGF) in cultured human fibroblasts, and to identify potential interrelationships between SPARC and CTGF.

METHODS

Fibroblasts from skin biopsy specimens of 2 normal individuals were transfected with siRNA of SPARC and siRNA of CTGF. The fibroblasts were stimulated with or without transforming growth factor beta1 (TGFbeta1) and examined by real-time quantitative reverse transcription-polymerase chain reaction to determine the transcription levels of several extracellular matrix genes.

RESULTS

After exogenous TGFbeta1 stimulation, both SPARC siRNA and CTGF siRNA showed a protective role against overexpression of collagen genes. Following TGFbeta1 stimulation, SPARC siRNA-transfected fibroblasts showed a greater reduction in expression of the collagen genes compared with CTGF siRNA-transfected fibroblasts, as well as a significantly decreased expression of CTGF (P < 0.05). Using linear structure equations to quantitatively model a genetic network based on expression levels of each gene, a positive regulatory role of SPARC on CTGF, COL1A2, COL3A1, COL11A1, and TIMP3 was observed. However, the regulatory role of CTGF on SPARC appeared to be negative and very small, while the positive regulatory effects of CTGF on COL1A2, COL3A1, COL11A1, and TIMP3 were less than those of SPARC.

CONCLUSION

The results of this quantitative comparison support the hypothesis that in these cultured fibroblasts, the regulatory effects of SPARC on some major extracellular matrix structural components are greater than those of CTGF. In addition, SPARC appears to regulate CTGF in a predominantly positive manner, while CTGF may act as a negative feedback control on SPARC following TGFbeta stimulation.

Killing effects of ganciclovir on human pulmonary adenocarcinoma cell A549 transduced with HSV1-TK gene in vitro and in vivo

AIM

To observe the killing effects of ganciclovir (GCV) on the human pulmonary adenocarcinoma cell A549 transduced with Herpes simplex virus I type thymine kinase (HSV1-TK) gene in vitro and in vivo.

METHODS

A retroviral vector containing the TK gene was constructed and transduced into a pulmonary carcinoma cell A549 by electroporation, to observe the sensitivity of the transfected cell to GCV in vitro and the bystander effect (MTT assay). Tumor cell apoptosis caused by the TK/GCV system was observed with a flow cell meter (FCM) and a scan electronic microscope (SEM). Recombination and expression of the TK gene were examined with DNA PCR and in situ hybridization, respectively. The therapeutic effect of GCV on subcutaneous tumor growth between transfected and parental cells was also compared.

RESULTS

The sensitivity of the transfected cell to GCV was 46 times higher than that of the parental cell, and the bystander effect was stronger in high cell density than in low cell density. The subG0G1 peak was shown on the DNA histogram after A549-Tk cell was treated with 50 micromol/L GCV for 3 days by FCM, but not in the A549 cell. A cell cycle analysis showed that the apoptotic cell in the A549-TK and A549 cells were (12.2+/-1.7) % and (1.3 +/- 0.3) %, respectively (P < 0.01). The cell apoptosis features of nuclear condensation, apoptotic vesicle, and nuclear showing semimoon feature were found in the A549-TK cell by SEM, but not in the A549 cell. Recombination and expression of the TK gene were positive in the transfected cell. In vivo, the growth of tumors formed by the transfected cell was apparently inhibited by GCV, but not in the control group.

CONCLUSION

The transfected cell obtained sensitivity to GCV and the bystander effect was closely related to intercellular touch. The TK/GCV system killing tumor cell was related to cell apoptosis. GCV inhibited the growth of tumors which were inoculated by A549-TK cell in vivo.

[Determination of unbound concentration of drug in drug-human serum albumin mixture by high performance frontal analysis]

A high performance frontal analysis(HPFA) method was developed to determine the unbound concentration of drugs in drug-human serum albumin (HSA) mixture under binding equilibrium. The sample was injected directly onto an internal-surface reversed-phase silica column (ISRP). The mobile phase was 67 mmol/L phosphate buffer (pH 7.4, I = 0.17 mol/L). When a large volume of sample solution under drug-HSA binding equilibrium was directly injected, the drug was eluted as a trapezoidal peak with a plateau, and the drug concentration in this region was the same as that of the unbound drug in the sample solution. The eluate of plateau region was collected and a small volume was injected onto a reversed-phase HPLC column. This HPFA-HPLC method was employed in the determination of unbound concentration in both ketoprofen (KP)-HSA and cefoperazone (CP)-HSA mixtures. The unbound concentrations of drugs obtained by using HPFA-HPLC were compared with those determined with ultrafiltration-HPLC. The effects of sample volume and flow rate of mobile phase on the plateau formation were investigated. It was found that the minimum injection volume to achieve a trapezoidal peak varied with drugs. The flow rate showed no effect on the trapezoidal peak formation. The unbound concentrations of KP and CP obtained were about the same by using HPFA-HPLC or ultrafiltration-HPLC and precisions were similar for both methods.

[Changes in SR Ca2+-ATPase activity, Ca2+ release and uptake kinetics of diaphragm muscle after different-frequency chronic electrical stimulation of diaphragmatic nerve]

To study adaptation of rabbit diaphragm muscle after different-frequency chronic electrical stimulation, Ca(2+)-ATPase activity and Ca(2+) release-uptake kinetics of sarcoplasmic reticulum (SR) were respectively measured by detecting inorganic phosphorus ion and Furo-2 fluorescence. SR Ca(2+)-ATPase activity of the low-frequency stimulation group was significantly lower than that of the control group (P<0.0l), but it was significantly higher in the high-frequency stimulation group against control (P<0.0l). The kinetics of Ca(2+) release and Ca(2+) uptake was significantly lower in low-frequency group than that of the control (P<0.0l), but the kinetics of Ca(2+) release and Ca(2+) uptake was significantly higher than that of the control (P<0.01). It is thought that different-frequency electrical stimulation induced different adaptative changes in SR Ca(2+)-ATPase activity, and Ca(2+) release and uptake kinetics of rabbit diaphragm muscle.

[Determination of bifonazole in cream by high performance liquid chromatography]

An accurate method for the determination of bifonazole in cream is described. The analytical column was packed with Hypersil ODS. The mobile phase was a mixture of 0.08 mol/L aqueous triethylamine (TEA) phosphate solution(pH 7.0)-acetonitrile-methanol (20:10:70, V/V) and the detection wavelength was 254 nm. This method is simple, accurate and can be used for the quality control of bifonazole in cream.

[Retrospective analysis of argon laser for treating retinal periphlebitis]

OBJECTIVES

This article was to investigate the curative effect of argon laser photocoagulation for retinal periphlebitis treatment, and then to discuss the stage of the treatment.

METHODS

According to the condition of vitreous hemorrhage and the range of retinal neovascularization, 31 cases (34 eyes) were divided into the light group and the heavy group, and the therapeutic effective rate, the condition of visual acuity and vitreous hemorrhage were compared.

RESULTS

The therapeutic effective rate was 64.71%, there was significant difference in effective rate and prognosis of visual acuity between two groups (P < 0.01). After laser treatment, the morbidity of vitreous hemorrhage in heavy group decreased from 100% to 18.70%.

CONCLUSION

Argon laser photocoagulation is an effective method for treating retinal periphlebitis and early treatment is recommended.

[mRNA and protein expression of skeletal DHPR(alpha1) and RyRs in diaphragm muscle of rabbits]

To detect mRNA and protein expression of skeletal dihydropridine receptor isoform alpha1 subunit and ryanodine receptor 1 and 3 in diaphragm muscle of rabbits, the coupling mode and characteristics of Ca(2+) release were explored. Reverse transcription PCR, in situ hybridization and immunohistochemical methods were employed. A higher level of mRNA and protein expression of DHPR(alpha1) and RyR(1), and a lower level of mRNA expression of RyR(3) were found. It is suggested that the calcium release unit may consist of skeletal DHPR isoform, RyR(1) and RyR(3), and there may be two kinds of Ca(2+) release mode via conformational changes in linked proteins and Ca(2+)-induced Ca(2+) release (CICR) in diaphragm muscle of rabbits.

[Adaptation of diaphragm muscle strip mechanics to chronic electrical stimulation and the effect of change in extracellular Ca2+ in rabbit]

AIM

The mechanical character of diaphragm muscle after chronic electrical stimulation(CES) and effect of the extracellular Ca2+ change have not yet been explored. We wondered whether there might be great different change and effect on muscle mechanics after CES and the extracellular Ca2+ change.

METHODS

The twitch tension(Pt), time to peak tension(TPT), half-relaxation time(1/2 RT), tetanic tension(Po), fatigue index (FI) and fatigue recovery index(FRI) were respectively measured in normal group and CES groups; the switch tensions of diaphragm muscle strips were observed in the standard Hank's solution and the Hank's with free Ca2+.

RESULTS

There were more significant decrease in Pt, Po, FI and FRI, more significant lengthening in TPT and 1/2 RT in 10 Hz and 20 Hz groups(P < 0.01). However, there was completely opposite effect in 50 Hz and 100 Hz groups. There were more significant effect on muscle mechanics of contraction and relaxation in 10 Hz and 20 Hz groups than that in 50 Hz and 100 Hz groups when the extracellular Ca2+ changed.

CONCLUSION

After CES the significantly frequency dependent were presented on mechanical character of diaphragm muscle strips, and there were more effect on diaphragm muscle mechanics in 10 Hz and 20 Hz groups when the extracellular Ca2+ was changed.

[Determination of three principal components in chuanjing tablets by using high performance liquid chromatography]

Uniform design method was employed to optimize the mobile phase of HPLC in order to determine simultaneously three principal components, theophylline, amobarbital and methylephedrine hydrochloride, in Chuanjing tablet, a compound preparation for asthma and cough. The stationary phase was ODS and the optimal mobile phase composition was V (0.015 mol/L phosphate buffer containing 0.3% triethylamine, pH 4.9): V (methanol) = 35:65. The detection was performed at 215 nm and the sensitivity was time programmed for simultaneous determination of minor and major components. Caffeine was selected as the internal standard. A baseline separation was achieved within 10 min. The linear ranges for theophylline, amobarbital and methylephedrine hydrochloride were 0.03 g/L-0.20 g/L, 7.5 mg/L-50.0 mg/L and 7.5 mg/L-50.0 mg/L, recoveries 99.7%-102.6%, 98.5%-100.2% and 98.0%-102.7%, inter-day RSDs 0.23%-1.2%, 0.35%-2.5%, 0.33%-1.6% respectively. This HPLC method is rapid and accurate, and suitable for the quality control of the preparation.

[Elementary events and characteristics of calcium signalling]

There are many different elementary intracellular calcium signalling in the cell. These events appear to have a hierarchical organization depending on stimulus intensity. Low levels of stimulation activate individual channels such as the blips or quarks; The next level of organization is the puffs and sparks, which appear to be derived from small clusters of channels. At high stimulus intensities these elementary events are coordinated to give global events. These events not only present the character of Ca2+ release unit, also lead to different complex spatiotemporal organization of calcium signalling, emphasizing the hierarchical organization and local control model of calcium signalling.