摘要:

ABSTRACT.The antiproliferative effects and ultrastructural alterations induced in vitro by two antifungal compounds, the azole ketoconazole and the allylamine terbinafine onLeishmania amazonensisare reported. Promastigotes treatment with ketoconazole and terbinafine induced growth arrest and cell lysis in 72 hours. Combination of the two agents produced additive effects on promastigote axenic growth and synergistic effects on intracellular amastigote proliferation. The amastigotes, either axenically grown or infecting murine macrophages, were about 100‐fold more sensitive to the drugs. These compounds induced the appearance of large multivesicular bodies, especially after ketoconazole treatment, increased amount of lipid inclusions as well as numerous, polymorphic volutin granules, particularly in terbinafine‐treated cells. Multivesicular bodies were observed in close apposition with organelles such as mitochondria, which also showed alterations in the distribution and appearance of cristae, and the formation of paracrystalline arrays within the matrix. Some cells presented large portions of cytoplasm wrapped by endoplasmic reticulum and many parasites also presented myelin‐like endoplasmic reticulum profiles. Such alterations together with the strong acid phosphatase activity observed in the multivesicular bodies and volutin granules may indicate the existence of an unusual autophagic process in cells treated with ergosterol biosynthesis inhib

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01591.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.Trophozoite extracts of axenicEntamoeba histolyticawere investigated by natural‐abundance13C‐NMR spectroscopy. The extracts were found to contain a high level of glycogen (30 mM glucose equivalents), which had a compact structure as suggested by α (1 → 6) branch points every 5–6 glucose residues. As other major metabolites, we identified putrescine (9.5 mM) and the following free amino acids: tyrosine and phenylalanine (1 mM), glycine, lysine and methionine (2 mM), isoleucine (5 mM), proline and valine (6–7 mM), leucine (11 mM) and glutamate (22 mM). Glutamate and proline may serve, together with putrescine, as intracellular

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01592.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.Haplosporidium nelsoniis a pathogen of the eastern oyster,Crassostrea virginica, along the middle Atlantic coast of the U.S. Genomic DNA was extracted fromH. nelsoniplasmodia and small subunit (SSU) rDNA was amplified by PCR, cloned and sequenced. The sequence ofH. nelsoniSSU rDNA was aligned with that of another haplosporidian,Minchinia teredinis, and with SSU rDNA data ofC. virginicaand various protists in GenBank. A 21‐base oligonucleotide unique toH. nelsoni, designated MSX1347, was commercially synthesized and tested for sensitivity and specificity. In dot blot hybridizations the probe detected 100 pg of clonedH. nelsonirDNA and the presence ofH. nelsoniin 1 μg of genomic DNA from an infected oyster. It did not hybridize with 1 μg of genomic DNA from uninfectedC. virginicaor with cloned SSU rDNA ofM. teredinis.The probe was further tested for specificity with in situ hybridizations on AFA‐fixed, paraffin‐embedded tissue sections. The probe hybridized well withH. nelsoniplasmodia and immature spores, but poorly with mature spores. The probe did not hybridize with oyster tissue, with other common oyster parasites such asP. marinusorNematopsissp., or with the haplosporidiansHaplosporidium louisianafrom mud crabs (Panopeusspp.),Haplosporidium costalefromC. virginicaorM. teredinisfrom shipworms (Tere

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01593.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.Epifluorescence microscopy and spectrofluorimetry were investigated as possible non‐terminal methods to distinguish live from dead foraminifera. Seven fluorogenic probes (diacetates of fluorescein [FDA], carboxyfluorescein, dichlorofluorescein, and carboxyeosin; AM‐esters of biscarboxyethylcarboxyfluorescein [BCECF‐AM], calcein, and calcein blue) were tested onAllogromia laticollaris. The probes that consistently produced the brightest fluorescence signals (BCECF‐AM and FDA) were judged non‐toxic toAllogromia, on the basis of short‐term pseudopodial deployment and long‐term reproduction assays. Once protocols were established, these two probes were tested on 13 additional benthic foraminiferal species. We found that BCECF‐AM is the most suitable probe for direct epifluorescence microscopy of metabolically active foraminifera, especially tectinous and transparent calcareous species. Using spectrofluorimetry, FDA showed promise for opaque species because fluorescence is detected in the incubation media after its release from the cell. However, both approaches could only be used with confidence in light of appropriate controls established for each s

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01594.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.A species ofEncephalitozoonhas been isolated from the urine of a patient with the acquired immunodeficiency syndrome and maintained in vitro in Madin Darby Canine Kidney cells. When examined by random amplified polymoprhic DNA polymerase chain reaction the new isolate was found to differ fromE. hellemand to have amplified products in common with murine and canineE. cuniculi. However, it more closely resembled the canine than the murine isolate. Sodium dodecylsulphate polyacrylamide gel electrophoresis differentiated between all three isolates ofE. cuniculi, with a band at 42–45 kDa present in the murine isolate only, bands at 52 kDa present in the canine and human isolates but not the murine, and a single band at 60 kDa (murine) and 65 kDa (canine) replaced by two bands at 55 and 70 kDa in the human isolate. The 55 kDa and 70 kDa antigens were also revealed as characteristic bands of the human isolate by Western blotting. The study has thus revealed that the speciesEncephalitozoon cuniculiis not a homogeneous entit

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01595.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.InEuglena gracilisZ, a considerably high activity of mono‐ADP‐ribosyltransferase occurred and change of it was accompanied by a cell cycle induced by a light‐dark cycle. The enzyme activity was strongly inhibited by L‐arginine and supported in the presence of poly‐L‐arginine as a substrate, indicating that ADP‐ribosylated amino acid is an arginine residue. Arginine: mono‐ADP‐ribosyltransferase activity was found in the chloroplasts, mitochondria, microsomes and cytosol as judged from marker enzyme activities and the activity in each organelle fluctuated wi

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01596.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.This work presents the further purification of a Cd‐linking protein inOxytricha granuliferaby reverse‐phase chromatography. This protein contains 25% cysteine and no aromatic amino acid. it may be considered as a chelatin with some similarity to metallothioneins. During the purification of another Cd‐linking compound, we were able to demonstrate that the H protein precursor of glycine cleavage is present inOxytricha.This is the first finding of the presence of this system in Pro

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01597.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.Because the in vitro cell cycle of the apicomplexan oyster pathogenPerkinsus marinusgenerates cell populations heterogeneous for size and typified by aggregation, both turbidimetric and counting methods for determining population densities and proliferation rates are inaccurate or cumbersome. We show that a commercial, tetrazolium‐based cell proliferation assay yields a soluble formazan chromophore upon intracellular reduction byP. marinus. at a rate proportional to cell population biovolume. Using this assay system, we have 1) defined selected culture system parameters which maximizeP. marinusin vitro proliferation, 2) assessed selected chemosensitivities, and 3) standardized the assay system for quantification of densities and doubling times of populations propagated with our optimized system. Growth was supported by four tested base media and was maximized in 1:1 DME/Ham's F‐12. Temperatures of 10–40° C permitted growth, which was maximized at 35° C. pH 6.0–8.5 permitted growth, which was maximized at 7.0–7.5. Osmolalities of 340–1,930 mOsm supported growth, which was maximized at 790 mOsm. Serum supplements from 1–10% (v/v) did not enhance log phase growth, but enhanced stationary phase metabolic activity in proportion to concentration. Our isolate (ATCC 50439) has a 13 h log phase doubling time when propagated under optimized conditions: 28° C, 800 mOsm, pH 7.0, 1:1 DME/Ham's F‐12 medium, 5% (v/v) FBS. It is tolerant of antibacterial agents at concentrations commonly used in vertebrate tissue culture, but is inhibited by several antimycotics at simi

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01598.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.A trichomonad flagellate strain R1 was isolated from the hindgut contents of the termiteReticulitermes santonensisFeytaud. The flagellate was cultivated at 28° C in anaerobic medium containing yeast extract, minerals and vitamins. The isolate fed on living bacteria. It showed the typical morphological and ultrastructural features of the trichomonads. closely resemblingTrichomitus trypanoides.In order to determine its phylogenetic position the small subunit ribosomal DNA (SSU rDNA) of the flagellate was amplified in vitro using the polymerase chain reaction (PCR), cloned in a plasmid vector and sequenced. Comparison of the obtained sequence with so far available SSU rRNA/rDNA sequences showed strongest similarity (89%) to the sequence ofTritrichomonas foetus.The phylogenetic analysis with parsimony and distance matrix methods placedTrichomitus trypanoidesstrain R1 near by the root of the phylogenetically so far analyzed eukaryotic organisms. This confirms that termites harbour hindgut symbionts, which originate from very early evolved eukaryotes

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01599.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT.The nucleotide sequence of the 16S rRNA gene, part of the 23S rRNA gene and the spacer DNA region was determined forGiardia duodenalis, obtained from humans in The Netherlands (AMC‐4) and Washington State (CM). These rDNA sequences differ from otherG. duodenalisisolates (Portland‐1 and BRIS/83/HEPU/106) both of which have virtually identical rDNA sequences. The most characteristic feature was found close to the 5’end of the 16S rRNA. The Portland‐1 ‐ Bris/83/HEPU/106 type has GCG in position 22–24, while AMC‐4 and CM have AUC in this position. These two sequences, present in an otherwise conserved region of the 16S rRNA, are “signature” sequences, which divideGiardiaisolates into two

ISSN:1066-5234    

DOI:10.1111/j.1550-7408.1995.tb01600.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY