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1.
Three Piper species, Piper longum, P. ribesoides and P. sarmentosum, were selected for investigation of adulticidal potential against Stegomyia aegypti, a main vector of dengue and dengue haemorrhagic fever. Successive extraction by maceration with 95% ethanol showed percentage yields of ethanolic extracts, which derived from P. longum, P. ribesoides and P. sarmentosum, of 8.89, 3.21 and 5.30% (w/w), respectively. All Piper extracts illustrated an impressive adulticidal activity when tested against female mosquitoes by topical application. The susceptibility of St. aegypti females to ethanol-extracted Piper was dose dependent and varied among the plant species. The highest adulticidal effect was established from P. sarmentosum, followed by P. ribesoides and P. longum, with LD50 values of 0.14, 0.15 and 0.26 microg/female, respectively. The potential of these Piper species, as possible mosquitocides, established convincing activity for further researches to develop natural substances for combat against adult mosquitoes.  相似文献   

2.
In endemic areas where malaria is prevalent, medicinal plants are often used to treat malaria. This study was conducted to evaluate the in vitro and in vivo antiplasmodial activity and cytotoxicity of extracts of meniran (Phyllanthus niruri L.) herb traditionally used to treat malaria in Indonesia. Three extracts viz aqueous, methanolic and chloroformic extracts were obtained by maceration of the herbs. A radioactive method was used to evaluate the in vitro antiplasmodial activity of the extracts on chloroquine-resistant (FCR-3) and chloroquine-sensitive (D-10) strains of Plasmodium falciparum. In vitro antiplasmodial activity was expressed by the concentration inhibiting 50% of parasite growth (IC50). Cytotoxicity was estimated on Hela cells and the Cytotoxicity Index (CI = IC50 on HeLa cells/IC50 on FCR-3 strain) was calculated to evaluate the safety of tested extracts. A standard 4-day test on P berghei infected mice was used to evaluate the in vivo antiplasmodial activity of the extracts showing strong in vitro antiplasmodial activity, for both the methanolic and aqueous extracts. The in vivo antiplasmodial activity was expressed by the dose inhibiting 50% of parasite growth (ED50). The IC50 values obtained for these extracts against P. falciparum ranged from 2.3 to 202.4 microg/ml. The methanolic extract was the most active in vitro extract with an IC50 that ranged from 2.3 to 3.9 microg/ml and a CI that ranged from 41.3 to 57.5. This was also the most in vivo active extract with an ED50 of 9.1 mg/kg/d. Further study will be conducted to isolate and purify active compounds presented in the methanolic extract.  相似文献   

3.
The in-vitro antiviral activity of a series of compounds in samples extracted from various parts of the Indian holy tree, Bael (Aegle marmelos corr.) were evaluated for their efficacy against human coxsackieviruses B1-B6. The inhibitory concentrations (IC50) for leaves (L1 and L2) stem and stem bark (S1, S2, S3 and S4) fruit (F1 and F2micro) root and root bark (R1 and R2) and pure compound, the marmelide were 1000 microg/ml (for L1 and L2), 1000 microg/ml (for S1, S2, S3 and S4), 1000 microg/ml (for F1) and 500 microg/ml (for F2) 250 microg/ml (for R1) and 500 microg/ml (for R2) and 62.5 microg/ml for marmelide respectively by plaque inhibition assay at 96 hrs. On the other hand, the corresponding value for Ribavirin, a standard antiviral drug, was 2000 microg/ml for the same viruses at the same time period. These concentrations did not exhibit any toxicity to Vero cells, the host subtoxic concentrations were 5000 microg/ml for leaf and stem fractions 2000 microg/ml for fruit fractions 500 and 1000 microg/ml for root fractions 250 microg/ml for marmelide and 2000 microg/ml for Ribavirin. The cytotoxic concentrations were 8000 microg/ml for leaf and stem compounds 4000 mg/ml for fruit; 1000 microg/ml and 2000 microg/ml for root 500 microg/ml for marmelide and 4000 microg/ml for ribavirin at 96 hrs. These were also confirmed by trypan blue dye exclusion test and further passaging of cells. Additionally pretreatment of host cells, virus inactivation, yield reduction and effect of time of addition assays against coxsackievirus B3 suggested that marmelide was most effective as a virucidal agent besides interfering at early events of its replicative cycle like adsorption, penetration, at various steps in single cycle growth curve and effect of time of addition.  相似文献   

4.
Plants in the genus Solanum (Solanaceae) produce a great variety of steroidal saponins and glycoalkaloids that confer natural resistance against several pests. Methanolic extracts of 13 Solanum species have now been tested for molluscicidal activity against Biomphalaria glabrata. The extracts investigated were prepared from the fruit of S. asperum, S. capsicoides, S. palinacantum, S. paludosum, S. paniculatum, S. paraibanum and S. sisymbriifolium, the aerial parts of S. asperum, S. capsicoides, S. crinitum, S. diamantinense, S. megalonyx, S. palinacantum, S. paniculatum, S. sisymbriifolium and S. torvum, and the roots of S. asperum, S. asterophorum, S. palinacantum, S. paludosum, S. paniculatum and S. stipulaceum. Encouragingly, the extracts from S. asperum, S. diamantinese, S. paludosum, S. sisymbriifolium and S. stipulaceum showed significant molluscicidal activity, the median lethal concentrations recorded (20-50 microg/ml) falling well below the threshold, of 100 microg/ml, set for a potential molluscicide by the World Health Organization.  相似文献   

5.
In this study the antineoplastic activity of methanolic extracts of six medicinal plants that are native to Iran, including Galium mite, Ferulago angulata, Stachys obtusicrena, Cirsium bracteosum and Echinophora cinerea was investigated. Different tumor cell lines were exposed to the extracts and cytotoxic analysis using MTT colorimetric assay was performed. Quantification of percentage of cells undergoing apoptotic changes by flow cytometry, and DNA fragmentation analysis on sensitive cell lines was then carried out. Results obtained indicated that almost all of the extracts more or less had the capacity to decrease the proliferation of tumor cells. Among the plants, the highest activity against K562 leukemia cell line was found for E. cinerea and C. bracteosum with IC50 less than 20 microg/ml followed by G. mite with IC50 of 39.8 microg/ml. F. angulata and E. cinerea, mostly inhibited Jurkat cells proliferation (IC50 less than 8 microg/ml). Fifty percent inhibition of Fen bladder cell carcinoma due to exposure to F. angulata and E. cinerea was found at concentrations of nearly 180 microg/ml. A549, a lung carcinoma cell, was mostly affected by S. obtusicrena (IC50 more than 200 microg/ml). In flow cytometry analysis, C. bracteosum, E. cinerea, F. angulata and S. obtusicrena extracts demonstrated no remarkable effects on the cell cycle profile of K562 and Jurkat cells. Moreover, in DNA fragmentation analysis of treated cells, no ladder formation was detected. In contrary, G. mite caused more than 40% apoptosis in the K562 and Jurkat cells. In DNA fragmentation analysis G. mite extract produced ladder formation in these cells. In conclusion, these results indicated that the extracts used in this study have anti tumor activity particularly against the leukemia cell lines and that apoptosis is the possible cause of cell death observed due to the extract of G. mite.  相似文献   

6.
The antimalarial activities of crude extracts and 17 fractions from the partition of 80%-methanolic extracts of three plants (the stem bark of Croton mubango, the stem bark of Nauclea pobeguinii and the leaves of Pyrenacantha staudtii) used as antimalarial remedies in the Democratic Republic of Congo were studied both in vitro (against Plasmodium falciparum) and in mice infected with Pl. berghei berghei. The toxic effects of dried aqueous extracts of the plants were also investigated, in uninfected mice. The most active crude extracts in vitro, with median inhibitory concentrations (IC(50)) of <1 microg/ml, were found to be the methanolic and dichloromethane extracts of C. mubango, and the dichloromethane extracts of N. pobeguinii and Py. staudtii. The aqueous extract with the most antimalarial activity in vitro was that of C. mubango (IC(50) = 3.2 microg/ml), followed by that of N. probeguinii (IC(50) = 5.3 microg/ml) and then that of Py. staudii (IC(50) = 15.2 microg/ml).Results from the in-vivo tests of antimalarial activity showed that, at a daily oral dose of 200 mg/kg, all the dichloromethane extracts, the petroleum-ether, chloroformic, ethyl-acetate and residual water-soluble fractions from C. mubango, and the chloroformic, ethyl-acetate and n-butanolic fractions from Py. staudtii produced >80% chemosuppression of the parasitaemias by day 4. The aqueous extracts of C. mubango and N. probeguinii produced a slightly lower but still significant inhibition of parasitaemia (60%-80%) whereas that of Py. staudtii only suppressed the day-4 parasitaemias by 37%.The dried aqueous extract of the stem bark of C. mubango showed some signs of toxicity in mice, with median lethal doses (LD(50)) of 350 mg/kg in the female mice and 900 mg/kg in the male. The extract significantly increased the serum concentrations of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) in mice of both sexes, but had no effect on the blood levels of creatinine or urea. No significant toxic effect was observed for the dried aqueous extracts of N. pobeguinii and Py. staudtii (LD(50) >5 g/kg). Neither of these extracts affected the serum concentrations of GPT or the blood concentrations of creatinine and urea, although the N. pobeguinii extract did increase the serum concentration of GOT.  相似文献   

7.
To increase understanding of immune response of host against G. hispidum, antigenic recognition of rodent gnathostomiasis were identified by the immunoblot method after PAGE of the advanced third stage larvae of G. hispidum and G. doloresi. The molecular weight of the major antigenic bands of G. hispidum extracts were 35 kDa and 16 kDa, and of G. doloresi were 48 kDa, 37 kDa and 35 kDa. Of these bands, the 35 kDa antigen of G. hispidum and G. doloresi was recognized with the sera of rats infected with G. hispidum 5 weeks after inoculation. Lecting staining with endoglycosidase-H or hydrolytic degradation on nitrocellulose strips revealed that the 35 kDa band of G. hispidum possessed the mannose-rich oligosaccharides. On the other hand, the band of G. doloresi had the hybrid-type glycopeptides. The larval extracts and excretory-secretory materials of G. hispidum were not antigenitically identical.  相似文献   

8.

SUMMARY

Schistosomiasis is a neglected disease with public health importance in tropical and subtropical regions. An alternative to the disease control is the use of molluscicides to eliminate or reduce the intermediate host snail population causing a reduction of transmission in endemic regions. In this study nine extracts from eight Piperaceae species were evaluated against Biomphalaria glabrata embryos at blastula stage. The extracts were evaluated in concentrations ranging from 100 to 10 mg/L. Piper crassinervium and Piper tuberculatum extracts were the most active (100% of mortality at 20 mg/L and 30 mg/L respectively).  相似文献   

9.
报告三明地区是猪刚刺颚口和陶氏颚口线虫病散发性流行区。猪刚刺颚口线虫感染率为5%,陶氏颚口线虫在家猪和野猪的感染率分别为4%和60.3%。浦城县是刚刺颚口线虫病散发性流行区,猪的感染率为4%,野猪感染率高达75%。鳝鱼是刚刺颚口线虫的重要第二中间宿主,也是主要传病媒介,三明地区鳝鱼的感染率为11.3%。我国(省)三种人兽共患颚口线虫第3期幼虫肠道上皮细胞核的数目有明显不同,棘颚口线虫每个上皮细胞多数有3—7个核,陶氏颚口线虫多数有2个核,刚刺颚口线虫成虫和幼虫大多数含有一个明显的核。文中还讨论了颚口线虫病的防治和诊断。  相似文献   

10.
The present study evaluated the in vitro efficacy of ciprofloxacin (CPFX) in combination with gentamicin (GM) using agar dilution checkerboard method against six blood culture isolates of Salmonella enterica serovar Typhi with CPFX minimum inhibitory concentration (MIC) values of 0.75 - 1.25 microg/ml and GM MIC values of 0.75 - 2 microg/ml. When used in combination, the fractional inhibitory concentration (FIC) values of CPFX and GM for the isolates ranged from 0.008 - 0.032 microg/ml and 0.1 - 0.2 microg/ml, respectively. The range of the FIC index from 0.121 - 0.216 indicated the synergistic effect between CPFX and GM for all the isolates. The time-kill method, which showed a 2.64 log(10) decrease in CFU/ml between the combination and its more active compound, also established synergism between CPFX and GM against one isolate employed in the method. These results may be helpful in making clinical decisions in the treatment of enteric fever due to the infection of multidrug resistant S. enterica serovar Typhi.  相似文献   

11.
Multiresistance in Stenotrophomonas maltophilia limits the effectiveness of antimicrobial therapy for infections due to this organism. It can be of special concern in cystic fibrosis (CF) patients due to frequent antimicrobial administration. The in vitro activity of 41 antimicrobial agents against 76 epidemiologically defined CF S. maltophilia isolates by pulsed-field-gel electrophoresis (PFGE) technique under XbaI and SpeI restriction was compared with that obtained with 51 non-CF strains recovered from respiratory sources. Minimal inhibitory concentrations (MICs) were determined with the standard National Committee for Clinical Laboratory Standards agar dilution technique, but with 24-hr incubation. Forty-seven different PFGE profiles were observed within 76 S. maltophilia CF isolates. Minocycline (resistance rate, 0%; MIC(90), 1 microg/ml), doxycycline (6.4%; 8 microg/ml), trovafloxacin (4.2%; 2 microg/ml), moxifloxacin (6.3%; 2 microg/ml), clinafloxacin (6.3%; 2 g/ml), and moxalactam (17.0%; 64 g/ml) displayed low resistance rates. On the contrary, resistance rates were higher with ceftazidime (70.0%; 256 microg/ml), cefepime (83.0%; 128 microg/ml), piperacillin (87.2%; >1,024 microg/ml), ticarcillin (87.2%; >512 microg/ml), and aztreonam (95.7%; >1,024 microg/ml). Clavulanate reverted resistance to ticarcillin and aztreonam in 40.4% and 31.7% of strains, respectively. Aminoglycosides displayed reduced activities with susceptibility rates lower than 20% and MIC(90) higher than 128 microg/ml. With the exception of trimethoprim-sulfamethoxazole (25.4 vs. 31.3%), CF isolates were more resistant than non-CF isolates. Remarkably, resistance was enhanced in S. maltophilia isolates persistently recovered in chronically colonized patients. Susceptibility analysis demonstrated higher resistance rates among CF S. maltophilia isolates when compared with respiratory isolates from non-CF patients. Moreover, persistently recovered CF S. maltophilia isolates were more resistant than sporadic non-CF isolates.  相似文献   

12.
氧氟沙星和左氧氟沙星抗结核分枝杆菌临床耐药界限的研究   总被引:10,自引:0,他引:10  
目的通过测定氧氟沙星(OFLX)及左氧氟沙星(LVFX)对101株临床分离的结核分枝杆菌的最低抑菌浓度(MIC)、分析MIC与既往氟喹诺酮类药物(Fos)的用药史及经过含有FQs方案治疗的疗效相关性,以期确定OFLX及LVFX的临床耐药界限.方法 1999年1月~2000年9月间在我院住院的结核病患者101例,留取痰或脓液行结核分枝杆菌培养、药敏试验及MIC,并系统观察47例肺结核患者接受含喹诺酮类药物治疗方案的痰菌阴转率和X线吸收好转率.各组间率的比较用X2检验. 结果(1)96%的菌株OFLX的MIC(MICF)比LVFX的MIC(MICV)高2倍.(2)既往未用过FQs治疗的临床分离株中,MICF<8.0μg/ml与MICV<4.0μg/ml者分别占91%及92%;既往曾接受FQs治疗的临床分离株中,MICF≥8.0μg/ml与MICV≥4.0μg/ml分别占54%及57%.(3)如以MICF≥8.0μg/ml、MICV≥4.0μg/ml为临床耐药界限,MICF<8.0μg/ml与MICF≥8.0μg/ml比较,3、6、12个月患者痰菌阴转率分别为54%、75%、82%及16%、32%、42%,两组比较差异均有非常显著性(P<0.01),两组12个月X线吸收好转率分别为89%、47%,差异有非常显著性(P<0.01);MICV<4.0μg/ml与MICV≥4μg/ml比较,3、6、12个月患者痰菌阴转率分别为53%、73%、83%及 12%、29%、35%,两组比较差异有非常显著性(P<0.01),12个月X线好转率分别为90%、41%,两组比较差异有非常显著性(P<0.01).结论 (1)曾接受FQs治疗的结核病患者的分离株MICF及MICV显著高于未接受FQs者.随着用药时间延长,MIC随之升高.(2)根据MICF及MICV与临床疗效分析结果,提示采用MICF≥8.0μg/ml、MICV≥μg/ml为临床耐药界限为宜.(3)既往曾接受FQs治疗的结核病患者,应行FQs的药敏试验,并坚持合理、联合用药的原则、防止耐药株产生.  相似文献   

13.
About 160 fluoroquinolones and derivatives were tested for antitrypanosomal activity in a drug sensitivity assay followed by fluorometric evaluation. The most active quinolone compounds had IC50 values in the range from 100 to 900 ng/ml, while several derivatives were not active at a concentration of 100 microg/ml. In a structure activity relationship study, modification of the quinolones at position R1, R2, R3 and R8 did not influence trypanocidal activity. An exchange of the fluor at position 6 may contribute to an increase in activity but does not entirely control it. Pyrrolidine substituents at position R7 generally were more active than other substituents at this position. Tetracyclic quinolone derivatives were amongst the most active compounds with IC50 values in the range of 0.3-8.8 microg/ml. The in vitro cytotoxicity on HT-29 cells was determined for active compounds with IC50 values below 1 microg/ml. In addition, six drugs with an IC50 below 1 microg/ml and a selectivity index of more than 10 were chosen for in vivo experiments. Dose escalation experiments with a maximum dose of 100 mg/kg/bid were performed in a mouse model without central nervous system involvement. For unknown reasons the in vitro effect of the drugs could not be confirmed in vivo, but the class of compound remains of interest for their mode of action, the low toxicity, pharmacological properties and the availability of a large number of synthesized compounds.  相似文献   

14.
The molluscicidal profile and brine-shrimp bio-activity of the ethanolic extracts of plants from the Bignoniaceae family were determined. The six extracts investigated were of the stems of Melloa quadrivalvis and Tabebuia aurea, and whole plants of Adenocalymma comosum, Arrabidaea parviflora, Cuspidaria argentea and Clytostoma binatum. When tested in the laboratory, with Biomphalaria glabrata as the test snail, all six extracts gave median lethal concentrations (9-54 microg/ml) that fell well below the upper threshold, of 100 mug/ml, set for a potential molluscicide by the World Health Organization.  相似文献   

15.
本文报告闽南地区猪刚刺颚口线虫病流行病学。终宿主猪检查790头,感染率为4.7%,感染强度1~16条虫。第2中间宿主鱼类检查12种,阳性3种,即黄鳝Monopterusalbus,乌鳢Ophiocephalusargus和胡子鲶Clariasbatrachus,感染率依次为30%,10%和4.2%,胡子鲶是国内外宿主新纪录。两栖类检查2种,均阴性。转续宿主蛇类检查5种,阳性4种,它们是银环蛇Bungarusmulticinctus、水泡蛇Enhydrisplumbea、渔游蛇Natrispiscator和中国水蛇E·chinensis感染率分别为71.4%,14.3%,12.5%和12.5%,这4种转续宿主均为国内外首次报告。调查结果显示,闽南地区是刚刺颚口线虫病散发性流行区。鳝鱼和银环蛇是传播本病的重要媒介。  相似文献   

16.
This study was undertaken to determine whether serum adiponectin and resistin levels are influenced by hyperthyroidism and autoimmune factors and to find out whether their levels are dependent on the presence of ophthalmopathy. We measured serum concentrations of adiponectin and resistin in 76 patients (63 women, 13 men) with Graves' disease (GD) and compared them with levels of the control group which consisted of 30 healthy subjects. Patients were separated into two groups according to the presence or the absence of thyroid-associated ophthalmopathy (TAO). TAO (-) group consisted of 26 subjects without eye signs of GD and TAO (+) group included 50 subjects with ophthalmopathy. The latter group was further divided into 2 subgroups: with active TAO [26 patients, clinical activity score (CAS)> or =4] and with inactive TAO (24 patients, CAS<4). Groups did not differ in age, sex, body mass index (kg/m2) and smoking habits. Compared with euthyroid subjects, hyperthyroid GD patients had elevated mean serum adiponectin concentrations (19.96+/-4.97 microg/ml vs 15.01+/-3.99 microg/ml, p<0.001). However we did not observe any disparity between the TAO (-) and TAO (+) groups (20.60+/-5.06 microg/ml vs 19.63+/-4.94 microg/ml, p=ns). Comparing patients with a CAS> or =4 and patients with a CAS<4, we found similar mean serum concentrations of adiponectin (20.04+/-5.01 microg/ml vs 18.74+/-4.83 microg/ml, p=ns). Serum levels of resistin did not differ between the hyperthyroid patients and control subjects (13.11+/-4.26 ng/ml vs 12.82+/-4.75 ng/ml, p=ns). Serum resistin levels did not differ between TAO (+) and TAO (-) groups nor in patients with active and inactive TAO. Serum adiponectin correlated significantly with free T4 (FT4), free T3 (FT3), and TSH-R antibodies (TRAb) in GD patients (r=0.40, 0.41, and 0.37, respectively; p<0.001 for each). Serum resistin levels were not correlated with thyroid hormones and thyroid antibodies. The variables that in simple linear regression analyses were found to be correlated with serum adiponectin were then used in multiple regression analysis. In a model including adiponectin as dependent variable and FT4, FT3 and TRAb levels as independent variables, FT3 and TRAb remained as parameters independently related to adiponectin level (R2=0.35, p<0.001). CONCLUSIONS: Elevated serum adiponectin levels in GD patients are related to the degree of hyperthyroidism and autoimmune process. The presence and activity of ophthalmopathy is not a modifier of serum adiponectin and resistin.  相似文献   

17.
OBJECTIVE: To evaluate the effects of fluoxetine and amitriptyline on nitric oxide (NO), prostaglandin E2 (PGE2), and hyaluronic acid (HA) production in human synovial cells and synovial tissue cultures. METHODS: Human synovial cells, synovial tissue, and cartilage were cultured in the presence or absence of cytokines, lipopolysaccharides (LPS), fluoxetine, or amitriptyline. Production of NO, PGE2, and HA was determined in culture media. Sulfated glycosaminoglycan (S-GAG) synthesis was evaluated in cartilage by 35S incorporation. RESULTS: Fluoxetine (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) inhibited NO release by 56%, 62%, and 71%, respectively, in the media of synovial cells stimulated by interleukin-1alpha (IL-1alpha; 1 ng/ml) plus tumor necrosis factor alpha (TNFalpha; 30 ng/ml). Amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) caused a 16%, 27.3%, and 51.4% inhibition of NO release. Fluoxetine and amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) significantly (P<0.05) inhibited PGE2 release in the media of human synovial cells in the presence of IL-1alpha plus TNFalpha, in a dose-dependent manner (up to 88% inhibition). Fluoxetine (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) and amitriptyline (1 microg/ml and 3 microg/ml) significantly (P<0.05) inhibited PGE2 release in the media of human synovial tissue in the presence of LPS. Fluoxetine and amitriptyline (0.3 microg/ml, 1 microg/ml, and 3 microg/ml) also significantly (P<0.05) inhibited HA production by human synovial cells in the presence of IL-1beta plus TNFalpha. Fluoxetine and amitriptyline (1 microg/ml) partially reversed IL-1beta-induced inhibition of 35S-GAG synthesis by human cartilage cultures (P<0.05). Neither fluoxetine nor amitriptyline had a toxic effect on cells in the concentrations used. CONCLUSION: Inhibition of NO and PGE2 production by connective tissue cells is a mechanism by which some antidepressant medications may affect pain, articular inflammation, and joint damage.  相似文献   

18.
Emergence of bacterial resistance is a major issue for all classes of antibiotics; therefore, the identification of new classes is critically needed. Recently we reported the discovery of platensimycin by screening natural product extracts using a target-based whole-cell strategy with antisense silencing technology in concert with cell free biochemical validations. Continued screening efforts led to the discovery of platencin, a novel natural product that is chemically and biologically related but different from platensimycin. Platencin exhibits a broad-spectrum Gram-positive antibacterial activity through inhibition of fatty acid biosynthesis. It does not exhibit cross-resistance to key antibiotic resistant strains tested, including methicillin-resistant Staphylococcus aureus, vancomycin-intermediate S. aureus, and vancomycin-resistant Enterococci. Platencin shows potent in vivo efficacy without any observed toxicity. It targets two essential proteins, beta-ketoacyl-[acyl carrier protein (ACP)] synthase II (FabF) and III (FabH) with IC50 values of 1.95 and 3.91 microg/ml, respectively, whereas platensimycin targets only FabF (IC50 = 0.13 microg/ml) in S. aureus, emphasizing the fact that more antibiotics with novel structures and new modes of action can be discovered by using this antisense differential sensitivity whole-cell screening paradigm.  相似文献   

19.
OBJECTIVE: To study the safety, immunogenicity and pharmacokinetics of two intravenously administered human monoclonal antibodies (hMAb 2F5, 2G12) against HIV-1 in humans. DESIGN: Open label clinical phase I trial. SETTING: Primary institutional care. PATIENTS: Seven HIV-1-infected healthy volunteers with > or = 500 x 10(6)CD4 cells/l and < or = 10,000 HIV-1 RNA copies/ml, not treated with highly active antiretroviral therapy (HAART), entered and finished the study. INTERVENTIONS: and main outcome measures: Eight separate infusions of the hMAb were administered over a 4-week period (total dose 14 g). The safety was assessed by physical examination, blood chemistry, complete blood cell count and recording adverse events. 2F5 and 2G12 plasma levels were determined prior to and at the end of each infusion and during the follow-up period of 22 weeks. RESULTS: No clinical or laboratory abnormalities were observed throughout the study. The median distribution half-life (t(1/2 alpha)) of 2F5 and 2G12 was 1.02 (range, 0.77-1.47) days and 2.49 (range, 0.92-4.59) days, respectively. The elimination half-life (t(1/2 beta)) was calculated to be 7.94 (range, 3.46-8.31) days for 2F5 and 16.48 (range, 12.84-24.85) days for 2G12. The median plasma concentration immediately after the first infusion was 216 microg/ml (range, 158-409 microg/ml) for 2F5 and 238 microg/ml (range, 197-402 microg/ml) for 2G12. Multiple infusions resulted in maximum plasma concentrations of 374 microg/ml (range, 304-700 microg/ml) and 605 microg/ml (range, 479-897 microg/ml) for 2F5 and 2G12, respectively. CONCLUSIONS: This study showed that the hMAb 2F5 and 2G12 are safe and well tolerated by HIV-1-infected subjects.  相似文献   

20.
The aim of the present research was conducted to elucidate anti-septicaemic effect of a polysaccharide (PS) isolated from Panax ginseng C.A. Meyer (Araliaceae) by nitric oxide production from stimulated macrophage. In vitro assays for the activity measurement of PS, NO production test with Greiss reagent, phagocytic activity test using zymosan and cytokines production test using ELISA kit were also conducted. In vivo anti-septicaemic activity was assessed by using C57BL/6J mice. This was done with Staphylococcus aureus infection test. PS used at 0.025 mg/kg concentration showed a potent anti-septicaemic activity (80%, survival). However, it did not directly inhibit S. aureus in a minimum inhibitory concentration (MIC) test, conducted in vitro (data not shown). Nitric oxide production via macrophage activation showed the highest value of 5.5 nmol/ml at 1 microg/ml PS. In in vitro phagocytic activity test, PS at 10 microg/ml concentration showed a potent phagocytic activity for zymosan with 167% of the control. Production of TNF-alpha by macrophage activation at 10 microg/ml of PS was 96% lysis of L929. Also production of IL-1 and IL-6 by stimulation of macrophage with 100 microg/ml PS dose increased to 235 pg/ml and 0.47 ng/ml, respectively. The low mortality of PS treated (0.025 mg/kg) infected mice was concurrent with decreased bacterial content in the blood. Nitric oxide production in S. aureus infected mice whose macrophage was stimulated by PS (0.025 mg/kg) increased approximately 4 times than the untreated S. aureus infected group at 24 and 48 h incubation. In the PS treated (0.025 mg/kg) group, the intracellular concentration of S. aureus in macrophages decreased approximately by 50%, compared with the untreated group. Combine treatment with PS (0.025 mg/kg body weight) and vancomycin (10 mg/kg B.W.) resulted in 100% survival of the animals, whereas only 67% or 50% of the animals survived, respectively, when treated with PS or vancomycin alone. These results suggest that PS from Panax ginseng possess a potent anti-septicaemic activity by stimulating macrophage and a potentiality as an immunomodulator against sepsis occurred by Staphylococcus aureus.  相似文献   

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