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Wed, 24 May 2006


Progressive Esophagitis Caused by Candida albicans with Reduced Susceptibility to Caspofungin.

Pharmacotherapy 2006 Jun; 26(6): 877-80 (Read article online)
Miller CD, Lomaestro BW, Park S, Perlin DS

Candida esophagitis, a defining illness of acquired immunodeficiency syndrome (AIDS), requires systemic antifungal therapy. Candida albicans can become resistant to commonly administered azole antifungal agents. An attractive alternative is caspofungin, an echinocandin antifungal that has generally displayed predictable activity against C. albicans. We report the case of a 29-year-old woman with AIDS who developed recurrent esophagitis caused by a strain of C. albicans that showed reduced susceptibility to caspofungin (elevated minimum inhibitory concentration of 8 mg/L). Analysis of the strain revealed that it contained a serine-to-proline substitution at position 645 in the FKS1 gene. Clinicians who prescribe caspofungin to treat esophagitis caused by C. albicans should recognize the potential risk, albeit slight, for acquired resistance to caspofungin and possibly other echinocandin antifungal agents in the face of persistent disease. In patients who are refractory or unresponsive to caspofungin therapy, susceptibility testing and/or alternative therapy should be considered.

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Population growth rate and carrying capacity for springtails Folsomia candida exposed to ivermectin.

Ecol Appl 2006 Apr; 16(2): 656-65 (Read article online)
Noël HL, Hopkin SP, Hutchinson TH, Williams TD, Sibly RM

Forecasting the effects of stressors on the dynamics of natural populations requires assessment of the joint effects of a stressor and population density on the population response. The effects can be depicted as a contour map in which the population response, here assessed by population growth rate, varies with stress and density in the same way that the height of land above sea level varies with latitude and longitude. We present the first complete map of this type using as our model Folsomia candida exposed to five different concentrations of the widespread anthelmintic veterinary medicine ivermectin in replicated microcosm experiments lasting 49 days. The concentrations of ivermectin in yeast were 0.0, 6.8, 28.8, 66.4, and 210.0 mg/L wet weight. Increasing density and chemical concentration both significantly reduced the population growth rate of Folsomia candida, in part through effects on food consumption and fecundity. The interaction between density and ivermectin concentration was "less-than-additive," implying that at high density populations were able to compensate for the effects of the chemical. This result demonstrates that regulatory protocols carried out at low density (as in most past experiments) may seriously overestimate effects in the field, where densities are locally high and populations are resource limited (e.g., in feces of livestock treated with ivermectin).

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Role for Dendritic Cells in Immunoregulation during Experimental Vaginal Candidiasis.

Infect Immun 2006 Jun; 74(6): 3213-21 (Read article online)
Leblanc DM, Barousse MM, Fidel PL

Vulvovaginal candidiasis (VVC) caused by the commensal organism Candida albicans remains a significant problem among women of childbearing age, with protection against and susceptibility to infection still poorly understood. While cell-mediated immunity by CD4(+) Th1-type cells is protective against most forms of mucosal candidiasis, no protective role for adaptive immunity has been identified against VVC. This is postulated to be due to immunoregulation that prohibits a more profound Candida-specific CD4(+) T-cell response against infection. The purpose of this study was to examine the role of dendritic cells (DCs) in the induction phase of the immune response as a means to understand the initiation of the immunoregulatory events. Immunostaining of DCs in sectioned murine lymph nodes draining the vagina revealed a profound cellular reorganization with DCs becoming concentrated in the T-cell zone throughout the course of experimental vaginal Candida infection consistent with cell-mediated immune responsiveness. However, analysis of draining lymph node DC subsets revealed a predominance of immunoregulation-associated CD11c(+) B220(+) plasmacytoid DCs (pDCs) under both uninfected and infected conditions. Staining of vaginal DCs showed the presence of both DEC-205(+) and pDCs, with extension of dendrites into the vaginal lumen of infected mice in close contact with Candida. Flow cytometric analysis of draining lymph node DC costimulatory molecules and activation markers from infected mice indicated a lack of upregulation of major histocompatibility complex class II, CD80, CD86, and CD40 during infection, consistent with a tolerizing condition. Together, the results suggest that DCs are involved in the immunoregulatory events manifested during a vaginal Candida infection and potentially through the action of pDCs.

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Synthesis, a case of isostructural packing, and antimicrobial activity of silver(i)quinoxaline nitrate, silver(i)(2,5-dimethylpyrazine) nitrate and two related silver aminopyridine compounds.

Dalton Trans 2006 Jun 7; 2542-50 (Read article online)
Abu-Youssef MA, Langer V, Ohrström L

The synthesis and low temperature crystal structures of [Ag(quinoxaline)](n)(NO(3))(n), , [Ag(2,5-dimethylpyrazine)(NO(3))](n), and [Ag(4)(3-aminopyridine)(4)(NO(3))(4)](n) are presented. The quinoxaline compound forms a 1D coordination polymer with the characteristic linear 2-coordination figure of silver(i), the N-Ag-N angle being 164.2(1) degrees , and only weak silver-nitrate interactions. In addition there is an interaction giving pairs of parallel chains as the main structural theme. The 2,5-dimethylpyrazine compound has approximately trigonal-planar coordination, also binding one nitrate at the relatively short Ag-O distances 2.444(3) A and 2.484(3) A, respectively, for the two crystallographically different silver atoms. This also results in a 1D coordination polymer that, despite the large differences in the Ag(i) coordination environment, is isostructural with . [Ag(4)(3-aminopyridine)(4)(NO(3))(4)](n) forms a 2D coordination polymer by bridging nitrate ions. The antimicrobial activity of , and also of [Ag(3)(2-aminopyridine)(4)](NO(3))(3), was screened for 13 different pathogens and substantial activity was shown for against Escherichia coli and Pseudomonas aeruginosa (MIC 4 microg cm(-3)) and somewhat lower activity was registered against Sarcina lutea and Salmonella typhi for , Bordetella bronchiseptica for , Salmonella typhi and Pseudomonas aeruginosa for , and Escherichia coli and Shigella sonnie for (MIC 8 microg cm(-3)). Only low activity was shown against the yeast Candida albicans for , and whereas no activity against this pathogen was registered for .

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Candida resistance and its clinical relevance.

Pharmacotherapy 2006 Jun; 26(6 Pt 2): 68S-75S (Read article online)
Klepser ME

Since the 1970s, the death rate from Candida infection has risen in conjunction with increasing numbers of patients at risk for serious fungal infections, such as those immunocompromised because of tissue or organ transplantation, chemotherapy, acquired immunodeficiency syndrome, or advanced age. Candidal infections are not only prevalent but also associated with considerable mortality and morbidity. In 2005, the overall mortality rate was 44% within 30 days of the first blood culture positive for any Candida species. Given the substantial morbidity and mortality, clinicians must include fungal infection in the differential diagnosis for at-risk patients, and they must quickly select appropriate antifungal therapy for those with identified infection. However, clinicians cannot use the minimum inhibitory concentration to select antifungal therapy in the same way they use it to treat bacterial infections. The relationship between in vitro susceptibility and clinical effect is not as direct with antifungals as it is with antibiotics. As long as Candida species continue to be the major causes of fungal infections, improving outcomes remains an important therapeutic goal. A key element is preventing and managing drug resistance. Further study of treatment duration, dosage, intermittent-versus-continuous administration schedules, and other treatment options are needed to determine their effect on resistance. Therapy that combines agents with complementary mechanisms of action may increase potency and broaden the spectrum of antifungal efficacy while decreasing the number of resistant organisms.

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A screen for genes of heme uptake identifies the FLC family required for import of FAD into the endoplasmic reticulum.

Protchenko O, Rodriguez-Suarez R, Androphy R, Bussey H, Philpott CC

Although Candida albicans and Saccharomyces cerevisiae express very similar systems of iron uptake, these species differ in their capacity to use heme as a nutritional iron source. While C. albicans efficiently takes up heme, S. cerevisiae grows poorly on media containing heme as the sole source of iron. We identified a gene from C. albicans that would enhance heme uptake when expressed in S. cerevisiae. Overexpression of CaFLC1 (for flavin carrier 1) stimulated the growth of S. cerevisiae on media containing heme iron. In C. albicans, deletion of both alleles of CaFLC1 resulted in a decrease in heme uptake activity, while overexpression of CaFLC1 resulted in an increase in heme uptake. The S. cerevisiae genome contains three genes with homology to CaFLC1, and two of these, termed FLC1 and FLC2, also stimulated growth on heme when overexpressed in S. cerevisiae. The S. cerevisiae Flc proteins were detected in the endoplasmic reticulum and the FLC genes encoded an essential function, as strains deleted for either FLC1or FLC2 were viable, but deletion of both FLC1 and FLC2 was synthetically lethal. FLC gene deletion resulted in pleiotropic phenotypes related to defects in cell wall integrity. High copy suppressors of this synthetic lethality included three mannosyltransferases, VAN1, KTR4, and HOC1. FLC deletion strains exhibited loss of cell wall mannose phosphates, defects in cell wall assembly, and delayed maturation of carboxypeptidase Y. Permeabilized cells lacking FLC proteins exhibited dramatic loss of FAD import activity. We propose that the FLC genes are required for import of FAD into the lumen of the endoplasmic reticulum, where it is required for disulfide bond formation.

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Cellular and humoral systemic and mucosal immune responses stimulated in volunteers by an oral polybacterial immunomodulator "Dentavax".

Int Immunopharmacol 2006 Jul; 6(7): 1181-93 (Read article online)
Petrunov B, Marinova S, Markova R, Nenkov P, Nikolaeva S, Nikolova M, Taskov H, Cvetanov J

The oral polybacterial immunomodulator Dentavax (D), composed of killed cells from Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Candida albicans and Lactobacillus acidophilus and their lysates was created for immunoprophylaxis and therapy of oral mucosa and parodont inflammations. The stimulating effect of the preparation was evaluated in twelve volunteers immunized for 10 consecutive days. On days 7, 14, 21, 28 and 49 after the last immunization peripheral blood (PB) lymphocyte subsets, T lymphocyte activation and PB phagocytic activity, were studied by flow cytometry. PB lymphocyte proliferative responses to PHA, rIL-2, LPS and D were evaluated radiometrically. The production of TNF-alpha in supernatants of in vitro stimulated lymphocytes and specific IgA, IgM and IgG antibodies in serum and saliva was determined by ELISA. Ultrastructural morphologic changes in T and B lymphocyte populations were also investigated. Although no significant changes in the levels of basic lymphocyte subsets were detected, the early/late (CD57+/CD57-) CD8 T effectors ratio was increased at the end of the studied period, as were the percentage of PHA-responding (CD69+) T cells and PB phagocytizing cells. The most prominent lymphoprolipherative responses were measured upon costimulation with LPS+D and PHA+D on day 21. Electron-microscopic studies demonstrated a significant effect of D on both T and B cell activity. TNF-alpha concentration increased progressively from day 7 till the end of the investigation. Maximal concentrations were observed after stimulation with D and LPS. An increased level of specific salivary and serum antibodies against the components of D was found, with highest levels between days 7 and 21. Specific secretory IgA predominated in saliva as compared to IgM and IgG. Our results demonstrate the stimulating effect of Dentavax on PB lymphocyte functional activity and the specific humoral systemic and mucosal immunity.

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Modulation of telomere terminal structure by telomerase components in Candida albicans.

Nucleic Acids Res 2006; 34(9): 2710-22 (Read article online)
Steinberg-Neifach O, Lue NF

The telomerase ribonucleoprotein in Candida albicans is presumed to contain at least three Est proteins: CaEst1p, CaEst2p/TERT and CaEst3p. We constructed mutants missing each of the protein subunit of telomerase and analyzed overall telomere dynamics and single-stranded telomere overhangs over the course of many generations. The est1-DeltaDelta mutant manifested abrupt telomere loss and recovery, consistent with heightened recombination. Both the est2-DeltaDelta and est3-DeltaDelta mutant exhibited progressive telomere loss, followed by the gradual emergence of survivors with long telomeres. In no case was telomere loss accompanied by severe growth defects, suggesting that cells with short telomeres can continue to proliferate. Furthermore, the amount of G-strand terminal overhangs was greatly increased in the est2-DeltaDelta mutant, but not others. Our results suggest that in addition to their well-characterized function in telomere elongation, both CaEst1p and CaEst2p mediate some aspects of telomere protection in Candida, with the former suppressing excessive recombination, and the latter preventing excessive C-strand degradation.

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Brevinin-1BYa: a naturally occurring peptide from frog skin with broad-spectrum antibacterial and antifungal properties.

Pál T, Abraham B, Sonnevend A, Jumaa P, Conlon JM

Brevinin-1BYa (FLPILASLAAKFGPKLFCLVTKKC) is a cationic alpha-helical peptide containing an intramolecular disulphide bridge that is present in skin secretions of the foothill yellow-legged frog Rana boylii. A synthetic replicate of the peptide showed growth inhibitory activity against a range of reference strains of Gram-positive and Gram-negative bacteria, against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) (minimum inhibitory concentration (MIC)=2.5muM), and against reference strains and clinical isolates of the opportunistic yeast pathogens Candida albicans, Candida tropicalis, Candida krusei and Candida parapsilosis (MIC

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Atypical cutaneous manifestation of HSV-2 with Candida albicans co-infection in a patient with HIV-1.

Panasiti V, Devirgiliis V, Borroni RG, Spataro A, Melis L, Petrella MC, Pala S

Herpes simplex virus type 2 (HSV-2) infection was one of the first opportunistic infections identified among patients with AIDS. In the literature there are many data suggesting that the natural history of HSV-2 infection is altered in HIV-HSV-2 co-infected patients. Furthermore, a relationship between HIV seropositivity and HBV infection because of their analogous way of transmission is also described. We report the case of a 37-year-old patient who suffered from multiple painful ulcerative lesions of the perianal region. Laboratory examination showed positivity for HIV and HBV infections. In HIV-positive patients perianal HSV-2 can have atypical manifestations, especially if co-infection by Candida albicans occurs.

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Antibacterial activities of inorganic agents on six bacteria associated with oral infections by two susceptibility tests.

Fang M, Chen JH, Xu XL, Yang PH, Hildebrand HF

The antibacterial effects of six inorganic antibacterial agents were assessed using broth dilution and agar dilution tests on six pathogenic bacteria associated with oral infectious diseases: Streptococcus mutans (ATCC 25175), S. mutans (Ingbritt), Actinomyces viscosus (ATCC 15987), Lactobacillus casei (ATCC 393), Staphylococcus aureus (ATCC 29213) and Candida albicans (ATCC 90028). The results of the broth dilution test were significantly lower than those of the agar dilution test (F=38.290; P<0.01). The six inorganic agents notably inhibited the growth of tested common oral bacteria in vitro. Among them, Longbei inorganic antibiotic powder was the strongest antibacterial agent, followed by ZnO whisker antibacterial complex (ZnOw) AT-83, IONPURE-H, basic magnesium hypochlorite, ZnOw AT-88 and Antim-AMS2. The broth dilution test appears to be more suitable for testing insoluble inorganic agents.

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Mon, 22 May 2006


Oral supplementation with Lactobacillus casei subspecies rhamnosus prevents enteric colonization by Candida species in preterm neonates: a randomized study.

Clin Infect Dis 2006 Jun 15; 42(12): 1735-42 (Read article online)
Manzoni P, Mostert M, Leonessa ML, Priolo C, Farina D, Monetti C, Latino MA, Gomirato G

BACKGROUND: Colonization by Candida species is the most important predictor of the development of invasive fungal disease in preterm neonates, and the enteric reservoir is a major site of colonization. We evaluated the effectiveness of an orally supplemented probiotic (Lactobacillus casei subspecies rhamnosus; Dicoflor [Dicofarm spa]; 6 x 10(9) cfu/day) in the prevention of gastrointestinal colonization by Candida species in preterm, very low birth weight (i.e., < 1500-g) neonates during their stay in a neonatal intensive care unit. METHODS: Over a 12-month period, a prospective, randomized, blind, clinical trial that involved 80 preterm neonates with a very low birth weight was conducted in a large tertiary neonatal intensive care unit. During the first 3 days of life, the neonates were randomly assigned to receive either an oral probiotic added to human (maternal or pooled donors') milk (group A) or human milk alone (group B) for 6 weeks or until discharge from the NICU, if the neonate was discharged before 6 weeks. On a weekly basis, specimens obtained from various sites (i.e., oropharyngeal, stool, gastric aspirate, and rectal specimens) were collected from all patients for surveillance culture, to assess the occurrence and intensity of fungal colonization in the gastrointestinal tract. RESULTS: The incidence of fungal enteric colonization (with colonization defined as at least 1 positive culture result for specimens obtained from at least 1 site) was significantly lower in group A than in group B (23.1% vs. 48.8%; relative risk, 0.315 [95% confidence interval, 0.120-0.826]; P = .01). The numbers of fungal isolates obtained from each neonate (P = .005) and from each colonized patient (P = .005) were also lower in group A than in group B. L. casei subspecies rhamnosus was more effective in the subgroup of neonates with a birth weight of 1001-1500 g. There were no changes in the relative proportions of the different Candida strains. No adverse effects potentially associated with the probiotic were recorded. CONCLUSIONS: Orally administered L. casei subspecies rhamnosus significantly reduces the incidence and the intensity of enteric colonization by Candida species among very low birth weight neonates.

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Functional expression of Candida antarctica lipase B in the Escherichia coli cytoplasm-a screening system for a frequently used biocatalyst.

Liu D, Schmid RD, Rusnak M

In this paper, we report for the first time the functional expression of lipase B from the yeast Candida antarctica (CalB) in the Escherichia coli cytoplasm. The enzyme possessing three disulfide bonds was functionally expressed in the strain Origami B. Expression under the control of a lac promoter yielded 2 U mg(-1), whereas expression of a thioredoxin-CalB fusion protein yielded 17 U mg(-1). The native enzyme was most efficiently expressed under control of the cspA promoter (11 U mg(-1)). Coexpression of different chaperones led to a strong increase in active protein formation (up to 61 U mg(-1)). A codon-optimized synthetic variant of calb did not show significant effects on functional protein yield. Functional CalB expression was not only achieved in shake flasks but also in microtiter plate scale. Therefore, this CalB expression system is suitable for high-throughput applications, including the screening of large gene libraries as those derived from directed evolution experiments.

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Thrombin generation by exposure of blood to endotoxin: a simple model to study disseminated intravascular coagulation.

Stief TW

SUMMARY: Pathologic disseminated intravascular coagulation (PDIC) is a serious complication in sepsis. In an in-vitro system consisting of incubation of fresh citrated blood with lipopolysaccharides (LPS) or glucans and subsequent plasma recalcification plasmatic thrombin was quantified. Five hundred microliters of freshly drawn citrated blood of healthy donors were incubated with up to 800 ng/mL LPS (Escherichia coli) or up to 80 mug/mL Zymosan A (ZyA; Candida albicans) for 30 minutes at room temperature (RT). The samples were centrifuged, and 30 muL plasma were recalcified with 1 volume or less of CaCl(2) (25 mumoles Ca(2+)/mL plasma). After 0 to 12 minutes (37 degrees C), 20 muL 2.5 M arginine, pH 8.6, were added. Thirty microliters 0.9 mM HD-CHG-Ala-Arg-pNA in 2.3 M arginine were added, and the absorbance increase at 405 nm was determined. Fifty microliters plasma were also incubated with 5 muL 250 mM CaCl2 for 5, 10, or 15 minutes (37 degrees C). Fifty microliters 2.5 M arginine stops coagulation, and 50 muL 0.77 mM HD-CHG-Ala-Arg-pNA in 2.3 M arginine starts the thrombin detection. The standard was 1 IU/mL thrombin in 7% human albumin instead of plasma. Arginine was also added in the endotoxin exposure time (EET) or in the plasma coagulation reaction time (CRT). Tissue factor (TF)-antigen and soluble CD14 were determined. LPS at blood concentrations greater than 10 ng/mL or ZyA at greater than 1 mug/mL severalfold enhance thrombin generation, when the respective plasmas are recalcified. After 30 minutes EET at RT, the thrombin activity at 12 minutes CRT generated by the addition of 200 ng/mL LPS or 20 mug/mL ZyA is approximately 200 mIU/mL compared to approximately 20 mIU/mL without addition of endotoxin, or compared to about 7 mIU/mL thrombin at 0 minutes CRT. Arginine added to blood or to plasma inhibits thrombin generation; the inhibitory concentration 50% (IC 50) is approximately 15 mM plasma concentration. Endotoxin incubation of blood increases neither TF nor sCD14. This assay allows the study of the hemostasis alteration in PDIC, particularly in PDIC by sepsis. The thrombin generated by blood plus endotoxin incubation and plasma recalcification suggests that the contact phase of coagulation; e.g., triggered by cell components of (phospholipase-) lysed cells such as monocyte or endothelium DNA or phospholipid-vesicles (microparticles), is of primary pathologic importance in sepsis-PDIC. Arginine at plasma concentrations of 10 to 50 mM might be a new therapeutic for sepsis-PDIC.

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Signalling and oxidant adaptation in Candida albicans and Aspergillus fumigatus.

Nat Rev Microbiol 2006 Jun; 4(6): 435-444 (Read article online)
Chauhan N, Latge JP, Calderone R

Candida species and Aspergillus fumigatus were once thought to be relatively benign organisms. However, it is now known that this is not the case - Candida species rank among the top four causes of nosocomial infectious diseases in humans and A. fumigatus is the most deadly mould, often having a 90% mortality rate in immunocompromised transplant recipients. Adaptation to stress, including oxidative stress, is a necessary requisite for survival of these organisms during infection. Here, we describe the latest information on the signalling pathways and target proteins that contribute to oxidant adaptation in C. albicans and A. fumigatus, which has been obtained primarily through the analysis of mutants or inference from genome annotation.

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Dilated Intercellular Spaces: A Major Morphological Feature of Esophagitis.

Ravelli AM, Villanacci V, Ruzzenenti N, Grigolato P, Tobanelli P, Klersy C, Rindi G

OBJECTIVES:: Dilated intercellular spaces (DIS) in the esophageal epithelium have been identified by electron microscopy as marker of acid reflux damage in experimental animals and adults with gastroesophageal reflux disease (GERD). We aimed to identify and quantify DIS by light microscopy in pediatric GERD and esophagitis. METHODS:: We prospectively took esophageal biopsies in 70 consecutive pediatric patients, 48 of whom had GERD symptoms. On hematoxylin and eosin-stained sections esophagitis was scored histologically, and DIS were graded as 0 (absent), + (small and focal), ++ (moderate) or +++ (large and diffuse). A computerized image analysis identified total, cellular and nuclear areas and DIS were quantified as percentage of total minus cellular area. RESULTS:: Forty of 48 GERD patients had histological esophagitis (33 G1, 4 G2, 3 G3, 1 of which with Barrett esophagus), and all 40 had DIS (33 +, 4 ++, 3 +++) with 100% interobserver agreement; 15 of 29 (55%) had abnormal pH study (reflux index, 5.7%-36%). In 30 patients the esophagus was histologically normal. DIS values were 2.21% +/- 2.60% (range, 0.11%-12%) in patients with esophagitis and 0.44% +/- 0.13% (0.2%-0.7%) in patients with normal histology (P < 0.00001), with 0.71% bearing 70% sensitivity and 100% specificity for GERD versus controls. Five other children with esophagitis unrelated to GERD (eosinophilic, Candida, food allergy) also had DIS + to +++, and median DIS area was 5% (1.3%-12%). CONCLUSIONS:: DIS can be detected and evaluated by light microscopy, and the image analysis used provides an objective quantification of DIS and supports the light microscopy evaluation. DIS are a morphological feature of GERD and esophagitis in infancy and childhood.

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Toxicity, stability and pharmacokinetics of amphotericin B in immunomodulator tuftsin-bearing liposomes in a murine model.

Khan MA, Owais M

OBJECTIVES: In the present study we evaluated the pharmacokinetics and toxicity of amphotericin B in immunomodulator tuftsin-loaded liposomes in a murine model. METHODS: Stability of amphotericin B liposomes was tested by incubating one volume of liposomal formulations of amphotericin B with nine volumes of serum. The pharmacokinetics of amphotericin B in Candida albicans-infected mice treated with conventional and tuftsin-loaded amphotericin B liposomes was evaluated over a period of 24 h. In vitro toxicity of amphotericin B deoxycholate, as well as amphotericin B liposomes, was tested by incubation with human erythrocytes for 1 h at 37 degrees C. To assess amphotericin B-induced in vivo toxicity, BALB/c mice were injected with three doses of amphotericin B deoxycholate, as well as amphotericin B liposomal formulations on days 1, 2 and 3 post C. albicans infection. Blood from treated mice was taken by retro-orbital puncture to test renal function parameters such as serum creatinine and urea. RESULTS: In vitro stability studies revealed that tuftsin-bearing amphotericin B liposomes released only 11% of the total liposomal amphotericin B in the serum, while it was found to be 19% from identical tuftsin-free amphotericin B liposomes. Both tuftsin-loaded as well as tuftsin-free liposomal formulations of amphotericin B induced approximately 20% haemolysis of erythrocytes at a dose of 40 mg/L, while the same amount of drug in amphotericin B deoxycholate caused 100% lysis of the erythrocytes. Pharmacokinetic studies revealed that subsequent to administration of various formulations of amphotericin B, there was 32 mg/L amphotericin B in the systemic circulation of mice treated with tuftsin-bearing amphotericin B liposomes, while it was 25 mg/L for amphotericin B liposomes, 4 h post drug administration. In vivo toxicity studies demonstrated that the amphotericin B deoxycholate formulation induced elevations in serum creatinine ( approximately 300% of control) and blood urea ( approximately 380% of control) values, while these values were substantially less (blood urea approximately 150% of control and serum creatinine approximately 210% of control) in the animals treated with the tuftsin-loaded amphotericin B liposomal formulation. Further, the administration of amphotericin B deoxycholate (1 mg/kg) in BALB/c mice at a dose of 1 mg/kg body weight led to the accumulation of 18.6 +/- 5.25 g/kg (of amphotericin B) in kidneys. On the other hand, administration of liposomal amphotericin B and tuftsin-bearing liposomal amphotericin B at a dose of 5 mg/kg body weight resulted in accumulation of 8.8 +/- 2.0 and 4.0 +/- 1.6 g/kg of amphotericin B, respectively, in the kidneys of treated animals. CONCLUSIONS: Co-administration of immunomodulator tuftsin along with liposomal formulations of amphotericin B successfully minimizes toxicity, as well as other side effects of the drug. Interestingly, tuftsin also increased the stability of liposomal amphotericin B. Superior efficacy, reliable safety and favourable pharmacodynamics of tuftsin-loaded amphotericin B liposomes suggest their potential therapeutic value in the management of fungal infections.

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Fungi lesions of maxillary sinus and comparative estimation of chlorhexedine bigluconate and Biopag antimicrobial action.

Afanas'ev VV, ShchipskiÄ­ AV, Efimov KM, Polikarpov NA

Having bacteriological assay of the material from maxillary sinuses the authors confirmed the presence of fungus infection. There were picked out and identified fungi Aspergillus niger, Candida albicans and Actinomyces israelii. Aspergillus niger can imitate on roentgenograms the picture of foreign body presence in maxillary sinus. Comparison of bactericidal activity of chlorhexedine bigluconate and Biopag showed the advantages of Biopag preparation.

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Stereoselective Enzymatic Synthesis of Chiral Alcohols with the Use of a Carbonyl Reductase from Candida magnoliae with Anti-Prelog Enantioselectivity.

J Org Chem 2006 May 26; 71(11): 4202-4205 (Read article online)
Zhu D, Yang Y, Hua L

In our effort to search for carbonyl reductases with anti-Prelog enantioselectivity, the activity and enantioselectivity of a carbonyl reductase from Candida magnoliae have been examined with various ketones of diverse structures. This carbonyl reductase catalyzed the reduction of a series of ketones, alpha- and beta-ketoesters, to anti-Prelog configurated alcohols in excellent optical purity. The usefulness of this carbonyl reductase has been demonstrated by synthesis of several chiral alcohol intermediates of pharmaceutical importance.

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Repression of CDC28 reduces the expression of the morphology-related transcription factors, Efg1p, Nrg1p, Rbf1p, Rim101p, Fkh2p and Tec1p and induces cell elongation in Candida albicans.

Yeast 2006 May 18; 23(7): 537-552 (Read article online)
Umeyama T, Kaneko A, Niimi M, Uehara Y

The ability of the human fungal pathogen Candida albicans to transit its cell shape is important for its pathogenicity. To obtain additional evidence that the cell cycle of C. albicans is associated with its morphology, we generated and characterized a conditional mutant of C. albicans CDC28, a cyclin-dependent kinase. In the constructed strain, the expression of CDC28 was regulated by the MET3 promoter and could be repressed in the presence of methionine and cysteine. Cdc28p-depleted cells demonstrated highly polarized growth and wider filaments than serum-induced hyphae. Hyphae-specific genes, HWP1, RBT4 and ECE1, were activated in the elongated filaments caused by the Cdc28p depletion. Furthermore, the protein expression levels of the transcription factors involved in morphological transition, Efg1p, Nrg1p, Rbf1p, Rim101p, Fkh2p and Tec1p, decreased under conditions that repress CDC28 expression. Taken together, these data indicate that repression of CDC28 affected the protein levels of the morphology-related transcription factors, the regulation of hyphae-specific genes and cell shape in C. albicans. Copyright (c) 2006 John Wiley & Sons, Ltd.

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