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.

Advances in research of colonic electrical stimulation

In recent years great attention has been paid to the study of colonic electrical stimulation. Colonic electrical stimulation is expected to become a valuable option for treatment of gastrointestinal dysfunction. This article reviews the classification, mechanisms and clinical applications of colonic electrical stimulation.

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.

[Technical study of vinpocetine micelles prepared by thin-film hydration method]

OBJECTIVE

To prepare PEG-PLA polymeric micelles loaded with vinpocetine (VP).

METHODS

VP micelles were prepared by thin-film hydration method, single factors affecting drug loading content, encapsulation efficiency, productivity, particle size and polydispersity index (PDI) such as dosage, type of organic solvent, quantity of organic solvent, hydration temperature, hydration speed, amount of hydration water, hydration time were investigated, and the optimum technology was obtained. The mean particle size and PDI were determined by DLS. The drug loading content, encapsulation efficiency, productivity of VP micelles were investigated by UV.

RESULTS

The drug loading content and particle size of VP micelles were 20.35% and 118.3 nm, respectively.

CONCLUSION

The technology of VP micelles prepared by thin-film hydration method is practical and simple. It's valuable to be further studied.

[Quantitative comparison of idiopathic interstitial pneumonias on high-resolution computed tomographic findings]

OBJECTIVE

To analyze the high-resolution computed tomographic (HRCT) findings of IPF (interstitial pulmonary fibrosis), NSIP (nonspecific interstitial pneumonia) and COP (cryptogenic organizing pneumonia) retrospectively through quantification methods and to explore their distinguishing features.

METHODS

Observers with no prior knowledge of the diagnosis evaluated the frequency, extent and distribution of various thin-section CT findings in 29 males and 17 females. The mean age was 50 ± 10 years old (range: 25 - 76). They had a histological diagnosis of IPF (n = 19), nonspecific interstitial pneumonia (NSIP) (n = 14) and cryptogenic organizing pneumonia (COP) (n = 13).

RESULTS

Ground-glass opacity, thickening of bronchovascular bundles and interlobular septal thickening were frequent features of IPF and NSIP. The frequency and extent of honeycombing and bronchiolectasis were more found in IPF than in NSIP and COP (P < 0.05). The frequency and extent of air space consolidation were more found in COP than IPF (P < 0.05). There were more number of segments with traction bronchiectasis and less extent of air space consolidation in IPF than NSIP and COP. The number of segments with traction bronchiectasis was less in NSIP than that of IPF and COP.

CONCLUSION

The various subtypes of idiopathic interstitial pneumonias often have the distinguishing characteristics easily identified on HRCT. Bronchiolectasis and honeycombing are valuable features for IPF; air space consolidation is a valuable feature for COP. The features of NSIP are also found in both IPF and COP so that additional features are required for both.

SKOV-3 cell imaging by paramagnetic particles labeled with hairpin cell-penetrating peptides

BACKGROUND

The hairpin cell-penetrating peptides (hCPPs) demonstrate an interesting characteristic of conditioned activation by molecules. We hypothesized that hCPPs have the potential to selectively deliver a paramagnetic gadolinium probe into the matrix metalloproteinase 2 (MMP-2) positive human ovary adenocarcinoma cell lines, SKOV-3.

METHODS

hCPPs were synthesized and labeled with 1,4,7,10-tetraazacyclododecane-N,N',N'',N''' tetraacetic acid gadolinium (III) (Gd-DOTA) and fluorescein isothiocyanate (FITC) by f-moc strategy using a standard solid phase peptide synthesis protocol. MMP-2 expression and activity were demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) and zymography. Internalization and location of hCPPs in SKOV-3 cells were observed by fluorescein imaging and flow cytometery. Selective delivery of Gd-DOTA in SKOV-3 cells was observed by magnetic resonance imaging (MRI) and transmission electron microscopy (TEM).

RESULTS

The uptake of hCPPs by SKOV-3 cells depended on the activity of MMP-2. T1WI signals of SKOV-3 cells treated with Gd-DOTA-hCPPs suggested the uptake of Gd-DOTA-hCPPs increased in a time- (r = 0.990, P < 0.01) and concentration-dependent manner (r = 0.964, P < 0.001), but was inhibited by a MMP-2 inhibitor. Electron-dense particles observed in the cytoplasm and nucleus by transmission electron microscopy proved the intracellular penetration of gadolinium.

CONCLUSIONS

hCPPs can be used as an effective vector for an MRI molecular probe to assess the activity of MMP-2.

[Evaluation of peripheral pulmonary embolism by different thickness of CTPA imagings]

OBJECTIVE

to evaluate whether there are difference among different thickness of CTPA imagings for detection of emboli in peripheral pulmonary arteries.

METHODS

CTPA Images of 97 patients with acute pulmonary embolism were divided into four series for each patient: 0.625 mm thick original transaxial soure images and 3 series of reconstructed images using the MIP technique with slab thicknesses of 1.25 mm, 2.5 mm, and 5.0 mm. The difference was compared among 4 series of CTPA images for detection of emboli in peripheral pulmonary arteries, and the agreement of 2 observers for detection of emboli in peripheral pulmonary arteries in different thickness images was tested. Chi-Square test was taken for comparison of 4 series of CTPA images for detection of emboli in peripheral pulmonary arteries. Kappa test was taken for the agreement of 2 observers for detection of emboli in peripheral pulmonary arteries.

RESULTS

the average images number of 0.625 mm, 1.25 mm, 2.5 mm, 5.0 mm thickness imaging was 403, 201, 101, and 53, respectively. For detecting clots in segmental pulmonary arteries, there was statistically significant difference between 5.0 mm thick imaging and other 3 series imagings (chi(2) = 60.099, P < 0.01), but agreement of 2 observers in each series imaging was excellent (value of κ from 0.751 to 0.973).For clots in sub-segment pulmonary arteries, no statistical significant difference was observed between 0.625 mm and 1.25 mm thick imagings (chi(2) = 1.051, P > 0.05), and superior to 2.5 mm and 5.0 mm thick images (chi(2) = 151.892, 204.553, respectively, P < 0.01), but agreement of two observers in each series imaging was good (value of kappa from 0.611 to 0.935).

CONCLUSION

compared with 0.625 mm thick transaxial imaging, 1.25 mm thick MIP imaging is equally sensitive for detecting emboli in peripheral pulmonary arteries, but needs fewer images and less time for image reading.

[Value of combined wells score and D-dimer test on diagnosing patients with deep venous thrombosis]

OBJECTIVE

To evaluate the value of Wells score or/and D-dimer test on diagnosing or excluding deep venous thrombosis (DVT).

METHODS

Patients with suspected DVT were retrospectively analyzed. All patients underwent clinical assessment, D-dimer assay and bilateral lower extremity compression sonography within 48 hours of admission. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing DVT by Wells score, D-dimer test, and combined Wells score and D-dimer were compared.

RESULTS

A total of 274 patients were analyzed. If low probability was defined as negative and moderate and high probabilities were defined as positive, the sensitivity, specificity, PPV and NPV of the Wells score were 78.4%, 66.1%, 52.3% and 86.6%, respectively. At a cut-off of 500 microg/L, the sensitivity, specificity, PPV and NPV of D-dimer test were 73.9%, 66.1%, 50.8% and 84.2%, respectively. If low probability and D-dimer < 500 microg/L were defined as negative, moderate and high probabilities and D-dimer > or = 500 microg/L were defined as positive, the sensitivity, specificity, PPV and NPV of the combined Wells score and D-dimer test were 88.3%, 76.8%, 67.1% and 92.5%, respectively.

CONCLUSION

For clinical suspected DVT patients, DVT diagnosis could be reliably obtained by combined Wells score and D-dimer test.

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.

Intercellular imaging by a polyarginine derived cell penetrating peptide labeled magnetic resonance contrast agent, diethylenetriamine pentaacetic acid gadolinium

BACKGROUND

The cellular plasma membrane represents a natural barrier to many exogenous molecules including magnetic resonance (MR) contrast agent. Cell penetrating peptide (CPP) is used to internalize proteins, peptides, and radionuclide. This study was undertaken to assess the value of a new intracellular MR contrast medium, CPP labeled diethylenetriamine pentaacetic acid gadolinium (Gd-DTPA) in molecular imaging in vitro.

METHODS

Fluorescein-5-isothiocyanate (FITC) and Gd-DTPA respectively labeled with CPP (FITC-CPP, Gd-DTPA-CPP) were synthesized by the solid-phase method. Human hepatic cancer cell line-HepG2 was respectively stained by FITC-CPP and FITC to observe the uptake and intracellular distribution. HepG2 was respectively incubated with 100 nmol/ml Gd-DTPA-CPP for 0, 10, 30, 60 minutes, and imaged by MR for studying the relationship between the incubation time and T(1)WI signal. The cytotoxicity to NIH3T3 fibroblasts cells was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide reduction assay (MTT).

RESULTS

The molecular weights of CPP labeled imaging agents, which were determined by MALDI mass spectrometry (FITC-CPP MW = 2163.34, Gd-DTPA-CPP MW = 2285.99), were similar to the calculated molecular weights. Confocal microscopy suggested HepG2 translocated FITC-CPP in cytoplasm and nucleus independent with the incubation temperature. MR images showed HepG2 uptaken Gd-DTPA-CPP had a higher T(1) weighted imaging (T(1)WI) signal, and that the T(1)WI signal intensity was increasing in a time-dependent manner (r = 0.972, P = 0.001), while the signal intensity between the cells incubated by Gd-DTPA for 60 minutes and the controlled cells was not significantly different (P = 0.225). By MTT, all concentrations from 50 nmol/ml to 200 nmol/ml had no significant (F = 0.006, P = 1.000) effect on cell viability of mouse NIH3T3 fibroblasts, compared with the control group.

CONCLUSIONS

The newly constructed CPP based on polyarginine can translocate cells by carrying FITC and MR contrast agent Gd-DTPA, and the intracellular concentrations are readily detectable by MR imaging, suggesting a new way for MR molecular imaging.

Application of cell penetrating peptide in magnetic resonance imaging of bone marrow mesenchymal stem cells

Tracking the distribution and differentiation of stem cells by high-resolution imaging techniques would have significant clinical and research implications. In this study, a model cell-penetrating peptide was used to carry gadolinium particles for magnetic resonance imaging (MRI) of mesenchymal stem cells (MSCs). MSCs were isolated from rat bone marrow and identified by osteogenic differentiation in vitro. The cell-penetrating peptide labeled with fluorescein-5-isothiocyanate (FITC) and gadolinium was synthesized by a solid-phase peptide synthesis method. Fluorescein imaging analysis confirmed that this new peptide could internalize into the cytoplasm and nucleus at room temperature, 4 degrees and 37 degrees . Gadolinium were efficiently internalized into mesenchymal stem cells by the peptide in a time or concentration-dependent manner, resulting in intercellular shortening of longitudinal relaxation enhancements, which were obviously detected by 1.5 Tesla Magnetic Resonance Imaging. Cytotoxicity assay and flow cytometric analysis showed that the intercellular contrast medium incorporation did not affect cell viability at the tested concentrations. The in vitro experiment results suggested that the new constructed peptides could be a vector for tracking MSCs.

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.