Experimental Study on the Antibacterial Effect of Origanum Volatile Oilon Dysentery Bacilli In Vivo and In Vitro

To observe the germistatic and germicidal effects of origanum volatile oil (OVI) on the dysentery bacteria, the abdominal cavity of mice was infected with Shigella sonne (Sh. sonnei) and Shigella flexneri (Sh. flexneri) F 2a. After OVI was given to the mice via gastric lavage, the effects of OVI on the infected mice were observed. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) for dysentery bacteria were determined in vitro. The results showed that origanum volatile oil showed obvious protective effect on mice infected with Sh. sonnei and Sh. flexneri F 2a. and it had germistatic and germicidal effects on dysentry bacteria. We are led to conclude that origanum volatile oil is an effective medicine against the infection of dysentery bacteria.

In Vitro Antibacterial Effect of Effective Microorganisms( EM) on Aeromonas hydrophila

In order to understand in vitro antibacterial effect of antibiotics and EM on Aeromonas hydrophila,14 isolates of A. hydrophila were isolated from diseased fish and aquaculture in the study. PCR amplification results of aerolysin gene( Aero gene) of isolates indicated that 7 out of 14 isolates were pathogenic A.hydrophila. In vitro antibacterial test indicated that 14 isolates were resistance to penicillin G,ampicillin,cephradine,cefazolin,tetracycline,terimethoprim,lincomycin and cephalexin,but showed high sensitivity to cefotaxime and furazolidone. In vitro antibacterial effect of EM on 14 isolates of A. hydrophila was positively correlated with concentration,and EM with the concentration greater than 60% had antibacterial effect on 14 isolates.

In-vitro Antibacterial Effect of Hedyotis hedyotidea Ethanol Extract

[Objectives]This study was conducted to investigate the antibacterial effect of the extract from Hedyotis hedyotidea(DC)Merr.[Methods]Through in-vitro antibacterial tests,the antibacterial effects of H.hedyotidea ethanol extract on Escherichia coli,Staphylococcus aureus and Bacillus subtilis were analyzed.[Results]The extract had a low-susceptibility inhibitory effect to the three kinds of bacteria,and the minimal inhibitory concentrations(MICs)corresponding to S.aureus,E.coli and B.subtilis were 200,175 and 150 mg/ml,respectively.The minimal bactericidal concentrations(MBCs)corresponding to E.coli and S.aureus were both 500 mg/ml.[Conclusions]This study provides theoretical support for the wide application of H.hedyotidea.

Antibacterial Effect of Nano-scale TiO_2 on Parasitic Bacterium of Nanfeng Citrus in Storage Period

[Objective] The aim was to observe the antibacterial effect of nano-scale Titanium dioxide on parasitic bacterium of Nanfeng Citrus in storage period.[Method] Nano-scale Titanium dioxide was prepared by dibutyl phthalate through sol-gel method under anhydrous conditions,and orthogonal experiment was used to determine optimum conditions for nano-scale Titanium dioxide preparation,and structure characterization of nano-scale Titanium dioxide was carried out by X-Ray diffractometer.Oxford cup method was used to explore inhibition effect of nano-scale Titanium dioxide suspension on the activity of normal parasitic bacterium of Nanfeng Citrus.Simultaneously,the empirical preservation test was carried out.[Result] The average diameter of nano-scale Titanium dioxide powder attained to 14.6 nm,actual average yield could reach 90.83% with RSD（Relative Standard Deviation）of 0.86%.[Conclusion] Nano-scale Titanium dioxide had good antibacterial effect on the parasitic bacterium of Nanfeng Citrus in storage period.

Antibacterial Effect of Cinnamon Oil Combined with Thyme or Clove Oil

Antibacterial effect of cinnamon oil combined with thyme or clove oil was studied in this paper. Agar dilution method was used to determine the minimum inhibitory concentrations （MICs） of the essential oils （EOs） of cinnamon, thyme, and clove oil against three Gram-positive bacteria （Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus）, and two Gramnegative bacteria （Escherichia coli and Salmonella typhimurium）. The results showed that cinnamon was a promising antibacterial substance with MIC ranged from 0.1 to 0.4 μL mL^-1 for the five bacterial species. Agar dilution checkerboard method was used to test the combined antibacterial effect of cinnamon oil with thyme or clove oil. Combination of cinnamon and thyme oil showed an additive effect against all selected bacteria, and combination of cinnamon and clove oil displayed an additive effect against B. subtilis, B. cereus, S. aureus, and an indifferent effect against E. coli and S. typhimurium. Furthermore, gas chromatography-mass spectrometry （GC-MS） measurement was used to analyze the components of the EOs, and the main components of cinnamon, thyme, and clove were cinnamaldehyde, thymol, carvacrol and p-cymene, and eugenol, respectively.

Antibacterial Effect of the Conducting Polyaniline

Excellent antibacterial performance of polyaniline （PAni） against Escherichia coli and Gram-positive Staphylococcus aureus microorganisms has been demonstrated under both dark and visible light conditions. The electrostatic adherence between the PAni molecules and the bacteria may play a very important role for the antibacterial reaction of the PAni. As a result of our investigation, conducting PAni and its composites/blends are believed to be useful as a new type of antibacterial agent, self-clean as well as multifunctional material for improving the human health and living environment.

Antibacterial Effects of Nanometallic Materials in Genetic Transformation of Anthurium by Agrobacterium-mediated Method

[Objective] This study was conducted to investigate the application of nanometallic materials in inhibiting Agrobacteriurn contamination in genetic transformation of Anthurium. [Method] Different nanometallic materials were added into Agrobacterium medium and Anthurium callus medium, to investigate the effects of their effects on Agrobacterium growth, callus growth and differentiation, and Agrobacterium contamination. [Result] Among the 4 nanometallic materials, NanoAg-2 showed a significant inhibitory effect on the growth of Agrobacterium, with a minimal inhibitory concentration of 25 mg/L. Even for the Anthurium calli or transgenic material contaminated by the Agrobacterium, a good antibacterial effect could be achieved after treating with 25 mg/L NanoAg-2 for 1 d with oscillation, the antibacterial rate reached 100%, and the Anthurium calli could grow and differentiate normally. [Conclusioa] NanoAg-2 could effectively inhibit Agrobacterium contamination, and its an- tibacterial effect is significantly better than cephalosporin and carbenicillin.

Initial Screening of 10 Plant Essential Oils in Vitro Antibacterial Activity Against Blueberry Pathogens

In order to develop natural antistaling agent for blueberries preservation,the antibacterial activities of 10 kinds of plant essential oils were analyzed by oxford-cup test and tube dilution method,and their inhibitory abilities to two kinds of representative Gram bacteria which are Escherichia coli and Staphylococcus aureus,and three kinds of harmful fungi in blueberries,involving Alternaria alternata,Penicillium digitatum and Botrytis cinerea,were tested.The results showed that 7 kinds of essential oils can inhibit the three fungi,among which cinnamon oil,clove oil,anise oil and thyme oil have strong fungi static efficacy.Cinnamon oil and thyme oil can effectively inhibit the Gram-positive bacterium(Staphylococcus aureus);cinnamon oil and masson pine oil are strongly inhibitory to Gram-negative bacterium(E.coli).Cinnamon oil has broad-spectrum ability to inhibit fungi,Gram-negative and positive bacteria,with a minimum inhibitory concentration(MIC)ranging from 0.0391 to 0.1560 L/mL.With strong inhibition effects on fungi,cinnamon oil can be used as a compound base oil and mixed with other essential oils to retain the freshness of blueberries,thus achieving better antibacterial and anti-corrosion effects.

The Inhibitory Effect of Extracts From Fructus lycii and Rhizoma polygonati on in vitro DNA Breakage by Alternariol

Alternariol caused DNA single-strand breakage. Conversion of the closed circular double-stranded supercoiled DNA (pBR 322) to the nicked circular form and linear form was used to investigate the effect of extracts of some Chinese medical herbs on DNA nicking induced by alternariol. Some substances in the extracts of Rhizoma polygonati (RP) and Fructus lycii (FL) were shown to protect DNA from the attack by alternariol.Some substance in the RP may bind to plasmid DNA, and this binding reduces the electrophoretic mobility of DNA. These results indicate that substances from FL and RP may be used as DNA protectors. It is possible that they play an important role in preventing cancer.

Toxicity Evaluation of in vitro Cultures of Freshwater Cyanobacterium Microcystis aeruginosa:Ⅰ.Hepatotoxic and Histopathological Effects in Rats

Laboratory cultures of freshwater cyanobacterium (blue-green alga) Microcystis aeruginosa PCC 7806 was cvaluated for its hepatotoxic effects in rats. The lyophilized cell extract injected intraperitoneally at 1 and 2 LD50 (15.8 and 31.6 mg/kg, respectively) produced significant increase in liver-specific enzymes viz. plasma alkaline phosphatase,γ-glutamyl transferase, lactate dehydrogenase with a concomitant decrease in hepatic glutamic pyruvic transaminase. A corresponding increase in liver body weight index and histopathological changes in liver (degeneration of hepatocytes, congestion and hemorrhage etc.) are indicative of a dose and time dependent hepatotoxic nature of the algal extract

Effect of Cadmium on Rat Leydig Cell Testosterone Production and DNA Integrity in vitro

Cadmium （Cd） is an elemental heavy metal with widely recognized toxicity. Its long-term use in industrial processes and daily activities has caused alarming levels of Cd contamination in the natural environment. According to the estimates by the Agency of Toxic Substances and Disease Registry in the US, 25 000 to 30 000 metric tons of Cd is annually released to the environment . Results of previous studies have demonstrated that several organs are targets of Cd, but the most important of these targeted organs may be the testes.

The Blocking Effect of Phenolic Acid on N-Nitrosomorpholine Formation in vitro

Phenolic acids (PAs) are widely found in many daily consumed vegetables and fruits.The inhibitory effects of PAs on Nnitrosomorpholine (NMOR) formation in vitro undersimulated gastric juice condition were studied. The results showed that the inhibjtoryIX)tency of thirteen varieties of PAs differed greatly, which may be related to theirchemical structures; the blocking rate (BR) of different killds of PAs were as follows:caf feic acid, 92.5%; tannic acid, 90.0%; gallic acid, 86.8%; sinaPinic acid, 86.2%; ferulicacid, 8l.l%; chlorogenic acid, 69.4%; gentisic acid, 69.2%; syringic acid, 62.1%; protocatechuic acid, 56.0%; p-coumaric acid, 52.5%; vannilic acid, 35.4%; moreover,p-hydroxybenzoic acid and m-coumaric acid had the least blocking effect or even slightcatalyzing effect. The results also demonstrated that amounts of NMOR formed werenegatively correlated with molar ratio of PAs to nitrite and that the optimum pH forinhibition was between 2 and 3.

THE SPECIFIC PHOTODYNAMIC EFFECTS OF MONOCLONAL ANTIBODIES CONJUGATED WITH HEMATOPORPHYRIN DERIVATIVE ON GASTRIC CANCER IN VITRO AND IN VIVO

Murine monoclonal antibody (MoAb) BB4.3, raised against the human gastric cancer cell line BGC823, was puriffied with Protein A-Sepharose CL-4B affinity chromatography and identified as IgG2a. It was then conjugated with a hematoporphyrin derivative (HPD) by using carbodiimide. The qualitative analysis of this conjugate showed that the amount of free HPD was negligible and there were no IgG aggregates among the conjugates. The conjugate retained both the antibody and photochemical activity of HPD.In vitro, the phototoxic effect of this HPD-BB4.3 conjugate on target cells was about 15 times higher than that of free HPD. The quality of selective photocytotoxicity was proven by the greater cytotoxi-city this conjugate showed than that of corresponding normal mouse IgG (NIgG) conjugated with HPD. It showed less cytotoxicity to colon cancer cell line B-80 (negative reaction to MoAb BB4.3) than to BGC825. Moreover, its cytotoxicity to BGC823 cells could be blocked specifically by excess BB4.3 antibody, but not by another MoAb 3G9, which combines with BGC823 at different binding sites from MoAb BB4.3.Nude mice inoculated with 2 × 10- BGC823 cells were given HPD-BB4.3, HPD, HPD-NIgG, HPD plus BB4.3 and PBS, respectively then exposed to light. Four out of six animals treated with the HPD-BB4.3 conjugate remained tumor-free for a long period. Although two developed tumors, there was a significant difference between the HPD-BB4.3-treated group and all the control groups in tumor induction time, tumor growth rate, and survival time (p<0.001). The HPD-BB4.3 conjugate inhibited the growth of established tumors by more than 40% in comparison with control groups (p<0.05).

Lethal effect of mononuclear cells derived from human umbilical cord blood differentiating into dendritic cells after in vitro induction of cytokines on neuroblastoma cells

BACKGROUND： Dendritic cell is the most major antigen presenting cell of organism. It is proved in recent studies that human umbilical cord blood mononuclear cells induced and cultured in vitro by recombinant human granulocyte-macrophage colony stimulating factor （rhG-MCSF） and recombinant human interleukin-4 （rhlL-4） can generate a great many dendritic cells and promote the lethal effect of T cells on human neuroblastoma, but it is unclear that whether the lethal effect is associated with the most proper concentration of dendritic cells. OBJEETIVE： To investigate the lethal effect of human umbilical cord blood mononuclear cells induced in vitro by cytokines differentiating into dendritic cells on human neuroblastoma, and its best concentration range. DESIGN ： Open experiment SEI-FING： Department of Pediatrics, the Medical School Hospital of Qingdao University MATERIALS ： The study was carried out in the Shandong Provincial Key Laboratory （Laboratory for the Department of Pediatrics of the Medical School Hospital of Qingdao University） during September 2005 to May 2006. Human umbilical cord blood samples were taken from the healthy newborn infants of full-term normal delivery during October to November 2005 in the Medical School Hospital of Qingdao University, and were voluntarily donated by the puerperas. Main instruments： type 3111 CO2 incubator （Forma Scientific, USA）, type 550 ELISA Reader （Bio-Rad, USA）. Main reagents： neuroblastoma cell line SK-N-SH （Shanghai Institute of Life Science, Chinese Academy of Sciences）, RPMI-1640 culture fluid and fetal bovine serum （Hyclone）, rhlL-4 （Promega, USA）, rhG-MCSF （Harbin Pharmaceutic Group Bioengineering Co.Ltd）, rat anti-human CDla monoclonal antibody and FITC-labeled rabbit anti-rat IgG （Xiehe Stem cell Gene Engineering Co.Ltd）. METHODS： ① Human umbilical cord blood mononuclear cells obtained with attachment methods differentiated into human umbilical cord blood dendritic cells, presenting typical morphology of dendritic cells after in vitro induction by rhG-MCSF and rhlL-4. ② Different concentrations of dendritic cells[ dendritic cells： neuroblastoma cells=20：1,50：1,100：1 （2×10^8 L^-1,5×10^8 L^-1,1×10^9 L^-1）], 1×10^9 L^-1 T cells and 1×10^7 L^-1 neuroblastoma cells were added in the experimental group. 1 ×10^9 L^-1 T cells and 1 ×10^7 L^-1 neuroblastoma cells were added in the control group. ③ Main surface marker CDla molecules of dendritic cells were detected with indirect immunofluorescence, and the percent rate of dendritic cells was counted with ultraviolet light and expressed as the expression rate of CD1a^＋ cells. ④Single effector cells and target cells were respectively set in the experimental group and control group to obtain the lethal effect. The lethal effect of dendritic cells on neuroblastoma cells was indirectly evaluated by detecting cellular survival with MTT assay. The lethal effect（%）= （1-A experimentat well-A effector cell /A target cell well）×100%.⑤The expenmental data were presented as Mean ±SD, and paired t test was used. MAIN OUTCOME MEASURES： ① Morphological characters of dendritic cells in the process of induction and differentiation. ②CD1a^＋ cellular expression rate. ③Lethal effect of dendntic cells on neuroblastoma cells. RESULTS： ①Morphological characters of dendritic cells in the process of induction and differentiation： On the 15^th day after human umbilical cord blood mononuclear cells were induced by rhG-MCSF and rhlL-4, typical morphology of dendritic cells could be seen under an inverted microscope. ②Expression rate of CD1a^＋ cells was （43.12±5.83）%. ③Lethal effect of dendritic cells on neuroblastoma cells： Lethal effect of dendritic cells stimulated T cells in each experimental group （ dendritic cells： neuroblastoma cells=100：1,50：1, 20：1 respectively） on neuroblastoma cells was significantly higher than that in control group[（31.00 ±4.41 ）%, （30.92±5.27）%,（33.57±5.35）%,（26.23±5.20）%, t=3.51,2.98,4.24, P〈 0.01 ）; But the lethal effect of dendntic cells on neuroblastoma was significantly lower when their ratio was 100：1 and 50：1 in comparison with 20：1 （t=2.01,2.36, P 〈 0.05）, and no significant difference in lethal effect existed between the ratio at 100：1 and 50：1 （t=0.06,P 〉 0.05）. CONCLUSION： Dendritic cells differentiated from human umbilical cord blood mononuclear cells after in vitro induction of cytokines can promote the lethal effect of T cells on neuroblastoma cells. The lethal effect is associated with the concentration of dendritic cells within some range.

The Antibacterial Effect of Silver-carrying B_2O_3-SiO_2-Na_2O Glass Material

The antibacterial effect of carrying silver B_2O_3-SiO_2-Na_2O glass material was studied by means of antibacterial ring, nephelometery,MIC value, thin film attachment and microcalorimetry, respectively. The experimental results of five kinds of antibacterial test methods are almost identical and can verify that carrying silver B_2O_3-SiO_2-Na_2O glass material exerts an excellent antibacterial performance. Antibacterial ring and nephelometery are simple, quick, but the precision is restrictive. MIC value, thin film attachment method and microcalorimetry can quantitatively compare the antibacterial effects of the antibacterial glass material.Compared with the traditional microbe test methods, the microcalorimetry can analyze the inhibiting effect of the cell's growth and metabolism on the antibacterial glass material by monitoring the thermal effect continuously and automatically.

Effect of Certain Toxicants on Gonadotropin-Induced Ovarian Non-Esterified Cholesterol Depletion and Steroidogenic Enzyme Stimulation of the Common Carp Cyprinus carpio in vitro

Isolated ovarian tissues from the common carp, Cyprinus carpio were incubated in vitro to obtain a discrete effect of four common toxicants of industrial origin, namely phenol, sulfide, mercuric chloride and cadmium chloride, on gonadotropin-induced alteration of nonesterified and esterified cholesterol and steroidogenic enzymes, △5-3β-HSD and 17β-HSD activity. Stage II ovarian tissue containing 30-40% mature oocytes were shown to be most responsive to gonadotropins in depleting only nonesterified cholesterol moiety and stimulating the activity of both. Safe doses of above mentioned toxicants when added separately to stage II ovarian tissue with oLH (1 μg/incubation) gonadotropin-induced depletion of nonesterified cholesterol and gonadotropin-induced stimulation of the activity of both enzymes was significantly inhibited. Esterified cholesterol remained almost unaltered. Findings clearly indicate the impairment of gonadotropin induced fish ovarian steroidogenesis by the four toxicants separately.

Study on Antibacterial Effect of Single Chinese Herbs on Staphylococcus aureus

[Objectives] This study was conducted to determine in-vitro antibacterial effect of 58 Chinese herbs on Staphylococcus aureus,and screen single Chinese herbs with better in-vitro antibacterial effect for formulation of prescription. [Methods]Effective components in Chinese herbs were extracted with water,and inhibition zone diameters and minimal inhibitory concentrations of the 58 Chinese herbs against S. aureus were determined by agar plate punching method and micro two-fold method,respectively. [Results] Twenty two kinds of Chinese herbs including Terminalia chebula Retz.,Anemarrhena asphodeloides Bunge.,Prunella vulgaris L,Rheum palmatum L. and Mosla chinensis Maxim. had better antibacterial effect,among which T. chebula Retz.,A. asphodeloides Bunge.,P. vulgaris L,R. palmatum L. and C. sappan Linn showed the best antibacterial effect,with average inhibition zone over 20 mm and MIC lower than 15. 6 mg/ml.[Conclusions]Traditional Chinese herbs have certain antibacterial effect,and this study will provide important theoretical reference for clinical medication and development of prescription.

STUDY ON EFFECTS OF Yb^(3+) AND ITS COMPLEXES ON CELLS IN VITRO

This paper reports the effects of the Yh^(3+) and its four complexes on cultured cells.The results indicate that the 5 mmol YbCl_3 has evident toxicity on cultured cells,and after it is coordinated with ligands,its toxicity is decreased.These.four complexes neither destroy the growth nor inhibit the adliesion of diploid cell to the surface of the flasket,but they inhibit the adhesion of cancer cells,and result in cell death.The complex of Yb~?(3+) with ligand(1) can destroy the cancer cells in division phase.forming aberrant mitotic cells,but the other three complexes of Yb^(3+) with ligands can destroy the cancer cells in interphase.These effects depend on the dose of the complex.

Study on Antibacterial Effects of Purple, Yellow and White-skinned Onions

Onion(Allium cepa L.)is a common biennial herb,and contains allicin compounds which can kill harmful microorganism.The antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations on Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)were studied.There were differences among the antibacterial effects of raw and mature onion juice of purple,yellow and white-skinned onions at different concentrations.What was more,the antibacterial effects of raw onion juice were better than those of the mature one.The antibacterial effects of high concentration onion juice were better than those of the low one.The content of the total flavonoids in raw purple onion was higher than that in mature onion,and reached extremely significant levels in 50%,75%and 100%,respectively.Through comparison,it was found that onion juice of purple-skinned had the best suppression effects on S.aureus(gram-positive bacterium)and E.coli(gram-negative bacterium),and gram-positive bacterium had better suppression effects than gram-negative bacterium.It wound provide the basis about bioactive function and antibacterial drugs.

ANTI-HUMAN LUNG GIANT CELL CANCER (PG) EFFECT OF HUMAN LAK CELLS IN VITRO AND IN NUDE MICE

Human LAK cells were prepared by culturing normal human peripheral blood mononuclear cells (PBMC) with or without rIL-2 and assayed for T cell surface markers as well as anti-tumor activity against PC in vitro and in nude mice. Although the percentages of T3, T4, and T8 positive cells in rIL-2-activated cells did not differ significantly from those of control cells in vitro, the former showed stronger cytotoxicity than control cells to PG tumor cells in vitro. In vivo, LAK cells completely inhibited the growth of PG tumor in nude mice, whereas PBMC control cells were to be of no effect. The anti-tumor effect of human LAK cells in nude mice may offer a useful model to study the role of human LAK cells against human tumor in vivo.