Activity of the new antifungal triazole, posaconazole, against Cryptococcus neoformans.

The new antifungal derivative posaconazole was tested against three clinical isolates of Cryptococcus neoformans var. neoformans using a broth microdilution procedure performed according to the guidelines established by the NCCLS. Posaconazole MICs were 0.125, 0.25 and 1.0 mg/L for isolates 491, 2337 and 486, respectively. To investigate the in vivo activity of this new compound, we established an experimental model of systemic cryptococcosis in CD1 mice by iv injection of cells of each strain of C. neoformans. Low (3 mg/kg/day) and high (10 mg/kg/day) doses of posaconazole were compared with amphotericin B given at 0.3 mg/kg/day for 10 consecutive days. Survival studies showed that all treatment regimens were effective in prolonging the survival of mice infected with C. neoformans 486 (P < 0.001). Only posaconazole at 10 mg/kg and amphotericin B were effective in prolonging the survival in mice infected with C. neoformans 2337 (P from <0.01 to <0.001), while neither agent was effective in mice infected with C. neoformans 491. Tissue burden experiments performed 24 h after the end of therapy revealed that posaconazole at 10 mg/kg was effective at reducing the fungal burden in both lung and brain tissues of all three strains of C. neoformans. In particular, for C. neoformans 491 and 2337 posaconazole was superior to amphotericin B at reducing the fungal burden in the brain (P < 0.05). The efficacy of posaconazole was also confirmed by determining the capsular antigen serum levels of treated mice versus untreated mice. Our study underlines the excellent activity of posaconazole against this pathogenic yeast.     

肺新型隐球菌感染1例

临床资料 患者女,53岁,已婚。因间歇发热、咳嗽、咯痰半年,胸闷、胸痛、气短1个月于2012年3月26日入院。患者于2011年10月开始无诱因出现发热、咳嗽,咯白色黏稠痰,伴畏寒,无寒战,体温最高达39．6℃,自服退热药后出汗,热可退,数小时后体温又升高,于当地医院诊治,未见好转。     

Efficacy of NS-718, a Novel Lipid Nanosphere-Encapsulated Amphotericin B, against Cryptococcus neoformans

In vitro and in vivo efficacies of NS-718, a lipid nanosphere-encapsulated amphotericin B (AMPH-B), have been studied. Of the tested AMPH-B formulations, NS-718 had the lowest MIC for Cryptococcus neoformans. In a murine model, low-dose therapy (0.8 mg/kg of body weight) with NS-718 showed higher efficacy than that with AmBisome. High-dose therapy (2.0 mg/kg) with NS-718 was much more effective than those with Fungizone and AmBisome. In mice treated with a high dose of NS-718, only a few yeast cells had grown in lung by 7 days after inoculation. A pharmacokinetic study showed higher concentrations of AMPH-B in lung following administration of NS-718 than after administration of AmBisome. Our results indicated that NS-718, a new AMPH-B formulation, is a promising antifungal agent for treatment of pulmonary cryptococcosis and could be the most effective antifungal agent against C. neoformans infections.     

In vitro and in vivo efficacies of the new triazole albaconazole against Cryptococcus neoformans

The activity of albaconazole (UR-9825; J. Uriach & Cía. S.A., Barcelona, Spain) was compared to that of fluconazole against 12 isolates of Cryptococcus neoformans in vitro and against 1 isolate in vivo in a rabbit model of cryptococcal meningitis. Albaconazole was 100-fold more potent in vitro than fluconazole on a per-weight basis and was fungicidal at potentially relevant concentrations for two isolates. MICs ranged from 相似文献   

In vitro interaction of flucytosine with conventional and new antifungals against Cryptococcus neoformans clinical isolates

Combinations of flucytosine with conventional and new antifungals were evaluated in vitro against 30 clinical isolates of Cryptococcus neoformans. Synergy determined by checkerboard analysis was observed with combinations of fluconazole, itraconazole, voriconazole, amphotericin B, and caspofungin with flucytosine against 77, 60, 80, 77, and 67% of the isolates, respectively. Antagonism was never observed. Killing curves showed indifferent interactions between triazoles and flucytosine and synergy between amphotericin B and flucytosine.     

Therapeutic efficacy of lanoconazole, a new imidazole antimycotic agent, for experimental cutaneous candidiasis in guinea pigs.

The therapeutic efficacy of 1% cream and 1% solution of lanoconazole, a new imidazole antimycotic agent, in the model of cutaneous candidiasis in prednisolone-treated guinea pigs was evaluated in comparison with that of comparable formulations of bifonazole. Each preparation was topically applied once a day for 3 consecutive days, starting on the fifth day postinfection, and quantitative culture study wsa conducted on the ninth day postinfection. Both formulations of lanoconazole were much more highly effective in terms of eradication of fungi than the bifonazole formulations.     

In vitro studies of a new antifungal triazole, D0870, against Candida albicans, Cryptococcus neoformans, and other pathogenic yeasts.

We investigated the effects of various assay conditions on the activity of D0870 against seven species of fungi in the broth macrodilution testing procedure proposed by the National Committee for Clinical Laboratory Standards (NCCLS). Multivariate analysis demonstrated that endpoint definition, starting inoculum size, medium composition, type of buffer, and length of incubation, but not pH or temperature, had significant effects on results. Increasing the inoculum from 10(2) to 10(5) yeast cells/ml raised the MICs for all isolates up to > 75,000 fold. This effect was greatest when endpoints corresponded to a 90% reduction in visually determined turbidity (MIC90), was less prominent with an 80% inhibition visual endpoint (MIC80), and was nearly absent with a 50% endpoint measured by a spectrophotometer (IC1/2). Differences due to medium composition were attributable to antibiotic medium 3 with RPMI and yeast nitrogen base media performing nearly identically. Under standardized conditions as specified in NCCLS document M27-P (Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Proposed Standard, 1992), 79 strains (5 to 25 strains for each species) demonstrated median MIC80s of 0.0037 and 0.0075 microgram/ml for Candida albicans and Cryptococcus neoformans, respectively. In contrast, Candida krusei and Torulopsis glabrata had a median MIC80 of 1.0 microgram/ml. Our studies indicate that the pathogenic yeasts C. albicans and C. neoformans are more susceptible to D0870 than other pathogenic yeasts.     

Short-term topical therapy of experimental tinea pedis in guinea pigs with lanoconazole, a new imidazole antimycotic agent.

The therapeutic efficacy of short-term treatment with a 1% cream of lanoconazole, a new imidazole antimycotic agent, in comparison with that of a 1% cream of terbinafine was evaluated in the guinea pig model of tinea pedis. Each agent was topically applied once a day for 3 or 7 consecutive days, starting on day 10 postinfection, and a culture study was conducted on day 5 after the last treatment with each agent. The 1% cream of lanoconazole was as highly effective as the 1% cream of terbinafine in terms of eradicating the fungi from the infected feet.     

Human astrocytes inhibit Cryptococcus neoformans growth by a nitric oxide-mediated mechanism

zeta and eta chains of the T cell antigen receptor (TCR) complex and the gamma chain of Fc receptors (FcR gamma) constitute a family of proteins important for the expression of, and signal transduction through, these receptors in hematopoietic cells. In zeta-deficient mice, TCR expression was reduced in most T cells. By contrast, CD8 alpha alpha + TCR-gamma/delta + intestinal intraepithelial lymphocytes in these mice expressed a normal level of TCR. Biochemical analysis of the TCR complex in these cells from zeta-deficient as well as normal mice revealed the predominant usage of FcR gamma. Furthermore, gamma/delta + T cells in epithelia of the skin and female reproductive organs from zeta-deficient mice also showed relatively high TCR expression, indicating the usage of FcR gamma. These observations demonstrate the preferential usage of FcR gamma by gamma/delta + T cells localized in epithelia of normal mice.     

Evaluation of Mycograb, amphotericin B, caspofungin, and fluconazole in combination against Cryptococcus neoformans by checkerboard and time-kill methodologies

This article reported the identification of heat shock protein 90 (hsp90) homologues by immunoblot in Cryptococcus neoformans. Mycograb, a genetically recombinant antibody against hsp90, was evaluated against 8 clinical isolates and the National External Quality Assessment Service for Microbiology strain of C. neoformans alone and in combination with amphotericin B, caspofungin, and fluconazole by checkerboard assay. At the end point of an optically clear well, the minimum inhibitory concentration (MIC) 0's ranged from 256 to 1024 microg/mL for Mycograb, from 0.5 to 1 microg/mL for amphotericin B, and from 16 to 32 microg/mL for caspofungin. The combination of Mycograb and amphotericin B produced a fractional inhibitory concentration index from 0.27 to 0.56, indicating a mainly synergistic effect, whereas for caspofungin, it varied from 0.5 to 2. At an end point of > or =50% inhibition, the MIC-2s varied from 16 to 128 microg/mL for Mycograb and from 0.125 to 16 microg/mL for fluconazole. The fractional inhibitory concentration index classified the combination as indifferent for 5 isolates, additive for 3 more isolates, and synergistic in a single isolate. Time-kill analysis on 2 isolates (F/7844 and F/10156), which had synergistic and additive results with amphotericin B, respectively, on checkerboard was performed with 4-16 microg/mL of Mycograb, 2-8 microg/mL of fluconazole, and 0.0625-2 microg/mL of amphotericin B. This demonstrated an increasingly static effect with augmenting concentrations of fluconazole and an initial static effect with amphotericin B at lower concentrations, which became fungicidal as the level of drug increased. The addition of either 4 or 8 microg/mL of Mycograb to 0.5 microg/mL of amphotericin B with C. neoformans F/7844 changed a static effect to a fungicidal effect at 8 h with an increased killing of 1.2 logs at 48 h. With C. neoformans F/10156, the addition of 16 microg/mL of Mycograb to 0.25 microg/mL of amphotericin B produced a difference in killing from 1 logarithm after 4 h to 1.5 logarithms after 48 h. These data suggest that the combination of amphotericin B and Mycograb would be worth exploring in the treatment of infection due to C. neoformans.     

Tetrathiomolybdate protects against cardiac damage by doxorubicin in mice

Cardiac toxicity is the limiting factor in therapy with doxorubicin, an otherwise useful cancer drug. In this article we detail our study of a mouse model of doxorubicin-induced cardiac toxicity in which, after 4 days' treatment, doxorubicin caused marked increases in plasma concentrations of creatine kinase, lactic dehydrogenase, and troponin I, indicators of cardiac injury; marked increases in the plasma concentrations of tumor necrosis factor-alpha and interleukin-1(beta), both inflammatory cytokines; and a marked increase in the plasma concentration of interleukin-2, an indicator of cytotoxic T-cell activation. Therapy with tetrathiomolybdate, designed to limit copper availability, eliminated almost all of the increases of these six parameters in plasma. The marked protection against cardiac injury by doxorubicin in tetrathiomolybdate-treated animals suggests that tetrathiomolybdate would be of use clinically in helping prevent doxorubicin toxicity in patients. In other preclinical work, it has been shown that tetrathiomolybdate potentiates the chemotherapeutic effect of doxorubicin in cancer, so a double benefit might accrue clinically from the combined use of tetrathiomolybdate and doxorubicin. The mechanism by which tetrathiomolybdate protects against doxorubicin toxicity is of considerable interest. Our working hypothesis, based on the inhibition of interleukin-2 by tetrathiomolybdate as shown here, is that tetrathiomolybdate interrupts the inflammatory cascade at the activated-T-lymphocyte stage.     

Postantifungal effects of echinocandin, azole, and polyene antifungal agents against Candida albicans and Cryptococcus neoformans

The postantifungal effect (PAFE) of fluconazole, MK-0991, LY303366, and amphotericin B was determined against isolates of Candida albicans and Cryptococcus neoformans. Concentrations ranging from 0. 125 to 4 times the MIC were tested following exposure to the antifungal for 0.25 to 1 h. Combinations of azole and echinocandin antifungals (MK-0991 and LY303366) were tested against C. neoformans. Fluconazole displayed no measurable PAFE against Candida albicans or Cryptococcus neoformans, either alone or in combination with either echinocandin antifungal. MK-0991, LY303366, and amphotericin B displayed a prolonged PAFE of greater than 12 h against Candida spp. when tested at concentrations above the MIC for the organism and 0 to 2 h when tested at concentrations below the MIC for the organism.     

In vitro activity of a new semisynthetic echinocandin, LY-303366, against systemic isolates of Candida species, Cryptococcus neoformans, Blastomyces dermatitidis, and Aspergillus species.

The in vitro activities of LY-303366, a new semisynthetic echinocandin, and comparators amphotericin B, 5-fluorocytosine, fluconazole, and ketoconazole against 205 systemic isolates of Candida species, Cryptococcus neoformans, Blastomyces dermatitidis, and Aspergillus species were determined. LY-303366 had MICs of < or = 0.32 microg/ml for all Candida albicans (n = 99), Candida glabrata (n = 18), and Candida tropicalis (n = 10) isolates tested. LY-303366 was also active against Aspergillus species (minimum effective concentration at which 90% of the isolates are inhibited, 0.02 microg/ml) (n = 20), was less active against Candida parapsilosis (MIC at which 90% of the isolates are inhibited [MIC90], 5.12 microg/ml) (n = 10), and was inactive against C. neoformans (MIC90, >10.24 microg/ml) (n = 15) and B. dermatitidis (MIC90, 16 microg/ml) (n = 29).     

Activity of SM-4470, a new imidazole derivative, against experimental fungal infections.

The antifungal activity of orally active SM-4470, (R)-3-(n-butylthio)-2-(2,4-dichlorophenyl)-1-(imidazole-1-yl)-2-propanol hydrochloride, was compared with that of ketoconazole. SM-4470 showed twofold-higher activity than ketoconazole in the oral treatment of systemic infection with Candida albicans in mice. In addition, SM-4470 was effective against aspergillosis in mice, but ketoconazole was ineffective. The efficacy of SM-4470 was similar to that of ketoconazole in curing experimental candidal vaginitis in rats and trichophytosis in guinea pigs, although its serum concentrations in these animals were lower than those of ketoconazole. These data suggest that SM-4470 may be of value in the treatment of both systemic and superficial fungal infections in humans.     

LL-37 protects rats against lethal sepsis caused by gram-negative bacteria

We investigated the efficacy of LL-37, the C-terminal part of the only cathelicidin in humans identified to date (termed human cationic antimicrobial protein), in three experimental rat models of gram-negative sepsis. Adult male Wistar rats (i) were given an intraperitoneal injection of 1 mg Escherichia coli 0111:B4 LPS, (ii) were given 2 x 10(10) CFU of Escherichia coli ATCC 25922, or (iii) had intra-abdominal sepsis induced via cecal ligation and puncture. For each model, all animals were randomized to receive intravenously isotonic sodium chloride solution, 1-mg/kg LL-37, 1-mg/kg polymyxin B, 20-mg/kg imipenem, or 60-mg/kg piperacillin. Lethality; growth of bacteria in blood, peritoneum, spleen, liver, and mesenteric lymph nodes; and endotoxin and tumor necrosis factor alpha (TNF-alpha) concentrations in plasma were evaluated. All compounds reduced lethality compared to levels in controls. Endotoxin and TNF-alpha plasma levels were significantly higher in conventional antibiotic-treated rats than in LL-37- and polymyxin B-treated animals. All drugs tested significantly reduced bacterial growth compared to saline treatment. No statistically significant differences between LL-37 and polymyxin B were noted for antimicrobial and antiendotoxin activities. LL-37 and imipenem proved to be the most effective treatments in reducing all variables measured. Due to its multifunctional properties, LL-37 may become an important future consideration for the treatment of sepsis.     

乳胶凝集法检测隐球菌荚膜多糖抗原在隐球菌性脑膜炎和隐球菌肺炎中的早期诊断价值

目的 研究乳胶凝集试验在隐球菌性脑膜炎和隐球菌肺炎中的早期诊断价值.方法 选取2005年1月至2006年4月广州市3家医院确诊的隐球菌性脑膜炎和隐球菌肺炎患者24例作为新生隐球菌组;选取念珠菌感染患者50例,细菌感染患者31例,怀疑隐球菌感染患者62例,正常者30名作为非新生隐球菌组,采用乳胶凝集试验检测隐球菌荚膜多糖抗原,并与培养和直接镜检方法相比较,评价其诊断的灵敏度和特异度.结果 乳胶凝集试验、培养和直接镜检3种方法诊断的灵敏度分别为96.2%、70.8%和83.3%,而特异度分别为99.4%、100.0%和100.0%.结论 乳胶凝集试验具有准确率高、快速简便的特点,可作为隐球菌性脑膜炎和隐球菌肺炎的早期诊断方法.     

Triphala, an ayurvedic rasayana drug, protects mice against radiation-induced lethality by free-radical scavenging

The effects of 10 mg/kg of triphala extract (TE) was studied on radiation-induced sickness and mortality in mice exposed to 7-12 Gray (Gy) of gamma-irradiation. Treatment of mice with triphala once daily for 5 consecutive days before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug double distilled water treated irradiated controls (DDW). Triphala provided protection against both gastrointestinal and hemopoetic death. However, animals of both the TE + irradiation and DDW + irradiation groups did not survive up to 30 days post-irradiation beyond 11 Gy irradiation. The LD50/30 was found to be 8.6 Gy for the DDW + irradiation group and 9.9 Gy for TE + irradiation group. The administration of triphala resulted in an increase in the radiation tolerance by 1.4 Gy, and the dose reduction factor was found to be 1.15. To understand the mechanism of action of triphala, the free radical scavenging activity of the drug was evaluated. Triphala was found to scavenge (.)OH, O(2) (.) 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonate) diammonium salt (ABTS)(.+) and NO(.) radicals in a dose dependent manner.     

A comparison of dynamic characteristics of fluconazole, itraconazole, and amphotericin B against Cryptococcus neoformans using time-kill methodology

This study evaluated the in vitro pharmacodynamics of fluconazole, itraconazole, and amphotericin B against Cryptococcus neoformans. MICs were determined for three clinical isolates according to NCCLS guidelines (M27). Time-kill studies were performed using antifungal concentrations of 0.25-32 x MIC and inocula of 10(3) and 10(5) CFU/ml. At predetermined time points over 72 hours, samples of each inoculum/drug combination were withdrawn and plated using a spiral plater. Colony counts were determined after incubation at 35 degrees C for 48 hours. Area under the kill curves (AUKCs) were plotted versus the AUC/MIC ratios. Inoculum effect was evaluated by calculating an estimated AUKC for the low inoculum then comparing it to the measured low inoculum using the unpaired Student's t-test. The MICs of fluconazole and itraconazole for isolate 97-1199, 97-1061, and 97-585 were 2, 4, 32 microg/ml and 0.03, 0.06, 0. 5 microg/ml, respectively. For amphotericin B, the MIC was 0. 25 microg/ml for each isolate. The triazoles demonstrated fungistatic activity against each isolate at both inocula with the exception of itraconazole against C. neoformans 97-585. Maximal suppression was noted at concentrations 8-16 x MIC correlating with an AUC/MIC of 192 for both inocula. Conversely, amphotericin B was fungicidal and displayed concentration-dependent activity against each isolate at both inocula. Maximal killing was observed at concentrations >4 x MIC for the low inoculum and >8 x MIC for the high inoculum for each isolate. No statistically significant differences were detected between the measured and estimated AUKCs for each antifungal agent. In conclusion, our results suggest that the triazoles were most effective against C. neoformans when concentrations were maintained at 8-16 x MIC. Amphotericin B, on the other hand, was concentration-dependent; thus, greater activity was exerted at higher concentrations.     

Resveratrol, a polyphenolic compound in red wine, protects against oxidized LDL-induced cytotoxicity in endothelial cells

BACKGROUND: Resveratrol, a polyphenolic constituent of red wine, has antioxidant effects. However, its protective effects against oxLDL-induced endothelial injury remained unclarified. METHODS: Primary human umbilical vein endothelial cell cultures (HUVECs) treated with oxLDL (200 microg/ml) were used to explore the protective effect of resveratrol. Cytotoxicity of oxLDL on HUVECs was studied by measuring lactate dehydrogenase (LDH) release, methylthiazol tetrazolium (MTT) and apoptotic cell death as characterized by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain. We also measured the production of reactive oxygen species (ROS) by using the fluorescnet probe 2', 7'-dichlorofluorescein acetoxymethyl ester (DCF-AM), and observed the activity of antioxidant enzymes. Furthermore, several apoptotic signaling pathway with increased cytosolic calcium, alteration of mitochondrial membrane potential, cytochrome c release and activation of caspase 3 were also investigated. RESULTS: Resveratrol attenuated oxLDL-induced cytotoxicity, apoptotic features, generation of ROS and intracellular calcium accumulation. OxLDL-induced mitochondria membrane potential collapase, cytochrome c release and activation of caspase 3 in HUVECs were also suppressed by resveratrol pretreatment. CONCLUSIONS: Red wine intake may protect against oxLDL-induced dysfunction of endothelial cells.     

改进的多重PCR技术鉴定白色念珠菌、新生隐球菌及烟曲霉的实验研究

[目的]建立一种快速而简便的鉴定白色念珠菌、新生隐球菌及烟曲霉的分子生物学方法。[方法]应用通用引物ITS1与ITS4，PCR扩增真菌的内转录间隔区（包含5．8SrDNA），然后将白色念珠菌、新生隐球菌、烟曲霉的单条种特异性异物与引物ITS1结合，对通用引物的扩增产物进行多重PCR扩增，达到鉴定上述菌株的目的。[结果]实验所采用的所有致病真菌，经通用引物的PCR扩增均能扩增出特异性的条带，而非真菌菌株扩增为阴性；白色念珠菌、新生隐球菌、烟曲霉的3种种特异性引物与ITS1结合进行的多重PCR扩增，只对目的菌株进行了有效扩增，其他菌株扩增为阴性。应用此方法对临床分离的菌株，白色念珠菌，新生隐球菌，烟曲霉进行鉴定，也得到特异性扩增条带。[结论]改进的多重PCR技术，更加经济，简单，快速，为致病真菌菌种的鉴定提供了有效手段。