bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Reversible Transformation of Leishmania braziliensis panamensis Between Promastigote and Ellipsoidal Forms1
Authors: DARLING T. N. , BLUM J. J. 
Published: May 2007

ABSTRACTRaising the temperature of a log‐phase culture of Leishmania braziliensis panamensis promastigotes from 26°C to 34°C resulted in formation of a culture containing 85% ellipsoidally shaped forms after 1.5 h. The temperature‐induced ellipsoidal forms decreased in size but persisted in high proportion (85–95%) for at least 12 h at 34°C. Recovery from the ellipsoidal forms to a culture containing 85–95% promastigotes was observed after returning the temperature to 26°C. The time required for recovery increased markedly with the duration of the preceding heat treatment, up to about 70 h for a 12‐h heat treatment.
Observations on the Caudal Cilium of the Tomite of Ichthyophthirius multifiliis Fouquet, 18761,2
Authors: GEISSLINGER MARK 
Published: May 2007

ABSTRACTLight microscopy of live or silver‐impregnated specimens of the fish parasite Ichthyophthirius multifiliis show that the tomites are elongated and claviform with the anterior end broad. The cytostome, indicated by the presence of the organelle of Lieberkühn, is found in the lower part of the broadened anterior third of the tomite. The tapered posterior end bears a rigid, caudal cilium at its pole. Scanning electron microscopy reveals the caudal cilium and associated structures, including the depression from which the cilium protrudes, circumciliary ring, and raised struts on the ring. From these observations it is concluded that a previously reported “apical filament” found on the tomite is actually the posterior caudal cilium described by Canella & Rocchi‐Canella in 1976.
Cytoskeleton of Toxoplasma gondii1
Authors: NICHOLS BARBARA A. , CHIAPPINO MARY LOUISE 
Published: May 2007

ABSTRACTThe cytoskeleton of Toxoplasma gondii was studied by electron microscopy using 1) whole mounts of detergent‐extracted parasites and 2) thin sections of routine preparations, tannic acid‐stained organisms, and detergent‐extracted parasites. In whole mounts, the spiral arrangement of the 22 pellicular microtubules closely corresponded to the pattern of surface ridges seen previously by scanning electron microscopy and reflected the torsion of the parasite body during locomotion. The microtubules had free posterior ends and were anchored anteriorly in the polar ring, presumed to be a microtubule organizing center (MTOC). The insertions of the microtubules were supported by blunt projections of the polar ring, forming a cogwheel pattern in transverse view. The internal microtubules had 13 protofilaments and were twice the length of the conoid. They extended through the conoid and ended at the anterior preconoidal ring, presumably a second MTOC. The subunits of the conoid were arranged in a counterclockwise spiral when traced from base to tip, as were the pellicular microtubules. We postulate that as the conoid moves, the polar ring complex moves along the spiral pathway of the conoid subunits. Retraction of the conoid would then rotate the polar ring, producing the torsion of the body we observed by SEM.
Mating Types in Aspidisca sp. (Ciliophora, Hypotrichida): a Cluster of Cryptic Species
Authors: DINI FERNANDO , BRACCHI PAOLO , GIANNÍ ALESSANDRO 
Published: May 2007

ABSTRACTA mating‐type analysis was performed on 78 stocks of the marine hypotrich ciliate, Aspidisca sp., from a sufficient number of diverse geographic locations, some widely separated. Evidence is provided for the existence of a binary mating system in this “morphospecies.” The collected stocks have been challenged by the most rigorous criterion, namely breeding affinity in the laboratory, and have yielded at least four reproductively, not necessarily geographically, isolated groups that are in fact “biological species,” here referred to as “syngens.” Different syngens contain different pairs of mating types. Syngens are morphologically indistinguishable; hence Aspidisca sp. can be considered a conservative taxon comprising a number of “cryptic” or “sibling species.” Information is also presented about the mating behavior and the pattern of nuclear events at conjugation in Aspidisca sp. Search for soluble pheromones of the mating types gave only negative results. Hence, direct contact with potential partners is postulated to play a critical role in preparing individuals to mate. Mating reaction and mating which actually involves cross‐fertilization (conjugation, sensu stricto) are completely inhibited by 10 μg/ml cycloheximide, suggesting the necessity of protein synthesis for recognition and union in conjugation of potential partners.
A Fast Electrophoretic Isoenzyme Technique for the Identification of Invasive and Non‐Invasive Entamoeba histolytica and “E. hitolytica‐like” Organisms
Authors: MOSS DELYNN M. , MATHEWS HENRY M. 
Published: May 2007

ABSTRACTCellulose acetate electrophoresis (CAE) was used to separate glucosephosphate isomerase, hexokinase, malic enzyme, and phosphoglucomutase extracted from invasive and non‐invasive Entamoeba histolytica and “E. histolytica‐like” organisms. Each of these morphologically similar organisms possessed a unique CAE isoenzyme profile that can be used as an aid in their identification. The CAE technique used to obtain these isoenzyme profiles is rapid, simple, and economical, and it requires neither specialized training nor claborate equipment.
Effects of Extracellular Potassium on Acid Release and Motility Initiation in Toxoplasma gondii
Authors: ENDO TAKURO , TOKUDA HAJIME , YAGITA KENJI , KOYAMA TSUTOMU 
Published: May 2007

ABSTRACTThe internal pH (pHi) of Toxoplasma gondii was estimated by measuring the accumulation of the weak base 9‐aminoacridine in buffers with various ionic compositions. The pHi of the metabolizing parasite increased when the extracellular K+ was elevated in alkaline medium or when the external pH (pHc) was substantially increased in medium employing high external K+ (90 mM). The parasite in mouse peritoneal fluid, or in potassium sulfate buffer (pH 8.2), where the pHi was demonstrated to be increased to 7.9, became motile when acidic buffer was substituted for the original suspension medium. This acid‐induced independent movement subsided within 5 min but was repeatedly induced if the pHc was serially lowered to 6.0. Basic buffers, on the other hand, abolished motility when applied to the moving parasites. Nigericin, which is known to collapse pH gradients across the membrane, also abolished motility.
Serology of Naegleria fowleri and Naegleria lovaniensis in a Hospital Survey1
Authors: DUBRAY BARBARA L. , WILHELM WALTER E. , JENNINGS B. R. 
Published: May 2007

ABSTRACTAn avidin‐biotin horseradish peroxidase method was used to detect antibodies to Naegleria fowleri and N. lovaniensis in human serum samples. Antibodies were detected in 101 specimens from 115 hospital patients ranging in age from 15 to 98 years. Class‐specific anti‐immunoglobulins identified antibodies as IgG and IgM. IgG antibody titers to both species ranged from 1:20 to 1:640. Seven of 15 serum samples collected from newborn infants also demonstrated IgG antibodies to these organisms with a titer range of 1:20 to 1:80. The immunoperoxidase test and Western blot analysis of selected serum samples demonstrated a close similarity in serological results between N. fowleri and N. lovaniensis.
Intestinal Ciliated Protozoa of African Rhinoceros: Two New Genera and Five New Species from the White Rhino (Ceratotherium simum Burchell, 1817)1
Authors: VAN HOVEN W. , GILCHRIST F. M. C. , HAMILTON‐ATTWELL V. L. 
Published: May 2007

ABSTRACTThis report represents the first published information on intestinal ciliated protozoa in the African white rhinoceros (Ceratotherium simum Burchell, 1817). Two new genera which do not relate to any known ciliated protozoa from the intestines of mammals and five new species are described. The ciliates were found in the colon of three of these free‐living hindgut‐fermenting grazers that were shot in widely spaced districts in southern Africa. Phalodinium digitalis n. gen., n. sp., Arachnodinium noveni n. gen., n. sp., Monoposthium vulgaris n. sp., M. bracchium n. sp., and M. latus n. sp. constituted between 1% and 10% of the total ciliate population (ca. 1 × 105/ml digesta) in the ascending colon. Exceedingly small numbers were observed in the descending colon, indicating temporary accommodation only.
Trypanosoma humboldti n. sp. from the Chilean Catshark, Schroederichthys chilensis (Guichenot, 1848)1
Authors: MORILLAS J. , GEORGE‐NASCIMENTO M. , VALERIA H. , KHAN R. A. 
Published: May 2007

ABSTRACTThe morphology of Trypanosoma humboldti n. sp. is described from living and stained specimens obtained from the blood of a catshark, Schroederichthys chilensis. This represents the first report of a trypanosome in fish from the eastern Pacific Ocean. It is distinguished by its size and apparent lack of pleomorphism. The presence of a leech, Branchellion ravenellii, attached to the catshark, raises the possibility that it can act as a vector. Additionally, this leech is recorded for the first time from the Pacific Ocean.
The Number of Species of Rodent Coccidia and of Other Protozoa
Authors: Levine Norman D. 
Published: May 2007

ABSTRACTAbout 447 species of coccidia have been named from the 1687 living, known species of rodents; 207 host species, 92 host genera, and 15 host families are represented; this is about 12% of the known species of rodents. About 4600 species of apicomplexan protozoa have been named. Assuming that the same proportion of the total number of apicomplexan species has been named as of the coccidian species, there must actually be about 38,333 species of apicomplexan protozoa. There are 5.4 times as many protozoan genera as of apicomplexan genera. Assuming that the number of species in each genus is the same for all the protozoa as it is for the Apicomplexa there may actually be 206,998 species of protozoa. This may be too conservative an estimate. Based on other criteria, an estimate of over 20 million species could be made.
Prevalence of Eimeria spp. (Apicomplexa: Eimeriidae) in Oregon Llamas1
Authors: RICKARD LORA G. , BISHOP JANELL K. 
Published: May 2007

ABSTRACTEimeria alpacae, E. punoensis, E. lamae, and E. macusaniensis were identified in fecal samples from 189 llama (Lama glama (L.)) adults and 50 llama crias (animals less than one year of age of any species in the genus Lama) from central and western Oregon. In both adults and crias, E. alpacae was the most common species found. The least common was E. macusaniensis, which was found in only two adults. Overall prevalence and numbers of animals with mixed infections was approximately twice as high in crias as in adults.
Protein Synthesis in Isolated Symbionts from the Flagellate Protozoon Crithidia deanei1
Authors: NOVAK ESTELA , HAAPALAINEN EDNA FREYMULLER , DA SILVA SOLANGE , DA SILVEIRA JOSE FRANCO 
Published: May 2007

ABSTRACTHere we describe a method that allows the isolation of intact trypanosomatid symbionts in amounts sufficient for biochemical analysis. The isolated symbionts retain their characteristic morphological features and are reasonably free of subcellular debris. They actively incorporate [3H]leucine and [35S]methionine into proteins. Chloramphenicol and rifampicin at 50 μg/ml almost completely inhibit the incorporation of protein precursors. The inhibition of protein synthesis by the antibiotics provides direct evidence for the existence of a prokaryotic protein‐synthesizing system in this unusual intracellular structure. The pattern of protein synthesis of the isolated symbionts is complex. Several symbiont polypeptides are absent or poorly represented in the flagellate.
Calcium Regulates the Regeneration of Cilia in Tetrahymena thermophila
Authors: JOGLAR‐RAMIREZ JOSE A. , RENAUD FERNANDO L. 
Published: May 2007

ABSTRACTA study of calcium metabolism in Tetrahymena during the regeneration of cilia evidenced that the process is inhibited by nifedipine and trifluoperazine. This suggests that calcium ions play an important regulatory role in this process. This was confirmed by studies on calcium uptake and efflux which showed that there was a net increase in calcium uptake prior to the reinitiation of motility. The increase coincided with a period of sensitivity to the calcium antagonist TMB‐8 and with an increase in the intracellular level of cGMP. The process was also inhibited by neomycin and stimulated by phorbol esters, which suggests that hydrolysis of phosphatidylinositol phosphates may take place as part of the calcium regulatory network during the regeneration of cilia.
Characterization of DNA from the Dinoflagellate Woloszynskia bostoniensis1
Authors: DAVIES W. , JAKOBSEN K. S. , NORDBY ø. 
Published: May 2007

ABSTRACTSome physical and chemical properties of DNA isolated from the dinoflagellate Woloszynskia bostoniensis were determined. Analytical cesium chloride gradient centrifugation gave a major component and a minor component banding at 1.719 and 1.693 g/cm, respectively. Thermal denaturation in 0.1 SSC showed a broad transition with a Tm of 70.5° C. Derivation of this curve indicated that two components were present having Tm values of 66° C and 70° C. Base composition analysis showed a GC content of 48.1% and a high degree of thymine replacement by 5‐hydroxymethyluracil. Two minor bases, identified as 5‐methylcytosine and N6‐methyladenine, were also detected. Reassociation kinetics showed a typical eukaryotic reassociation pattern with 45% repetitive and 55% single copy sequences.
Maintenance of Integrity, Viability, and Adhesion of Entamoeba histolytica Trophozoites in Different Incubation Media12
Authors: CANO‐MANCERA RAFAEL , LÓPEZ‐REVILLA RUBÉN 
Published: May 2007

ABSTRACTWe have determined the integrity, viability and adhesion of Entamoeba histolytica HK9 and HM1 trophozoites during their incubation in two basal culture media (TP and TYI) and three saline media (“maintenance medium” MM‐1 and two others buffered with HEPES). In basal culture media, more than 70% of the trophozoites maintained their integrity and adhesion to human red blood cells (RBC) for up to 4 h, and the proportion of those excluding Trypan blue decreased slowly after 2 h. In saline media, the number of ameba‐RBC complexes reached a maximum after 20–30 min and then decreased rapidly (and fastest in MM‐1), less than 10% of the amebae were intact after 3–4 h, and dye exclusion fell abruptly from the start of incubation. The number of ameba‐RBC complexes formed and the rate of adhesion were highest in basal TP medium. Normal nonvacuolated refringent (NVR) trophozoites deteriorated progressively in all media—although much faster in the saline ones—to vacuolated refringent (VR), nonrefringent, and disrupted. Trypan blue was excluded by all NVR and a fraction of the VR trophozoites. Horse serum helped to maintain ameba integrity and viability, but inhibited adhesion in a concentration‐dependent manner. We conclude that E. histolytica trophozoite integrity and adhesion are adequately preserved and should be characterized only in basal culture media, that refringence without vacuolization is a more stringent characteristic of ameba quality than Trypan blue exclusion, and that some serum component inhibits ameba adhesion.
Establishment of Endoreticulatus N. G. for Pleistophora fidelis (Hostounský & Weiser, 1975) (Microsporida: Pleistophoridae) Based on the Ultrastructure of a Microsporidium in the Colorado Potato Beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)1,2
Authors: BROOKS W. M. , BECNEL J. J. , KENNEDY G. G. 
Published: May 2007

ABSTRACTA new genus, Endoreticulatus n. g., is described for the microsporidium Pleistophora fidelis (Hostounský & Weiser, 1975) based on light and electron microscopic studies of a microsporidium in the Colorado potato beetle, Leptinotarsa decemlineata (Say). This latter microsporidium is considered to be conspecific with P. fidelis because both isolates have been shown to be infectious for L. decemlineata where infection is limited to the epithelial cells of the midgut; both are haplokaryotic and develop as groups of sporoblasts and spores in subpersistent vacuoles in the host cell. In addition, meronts, sporonts, and spores of each isolate often occur simultaneously in a common cell, and by light microscopy they both appear similar. Ultrastructural studies of the isolate from L. decemlineata revealed that all developmental stages occur in parasitophorous vacuoles derived from cisternae of rough endoplasmic reticulum of the host cell cytoplasm. Based on the unique nature of the parasitophorous vacuole, a new genus, Endoreticulatus, is proposed for P. fidelis. The genus is compared with the other genera whose species undergo multisporous sporogony in sporophorous vesicles. In addition, the nature of the parasitophorous vacuole of Endoreticulatus fidelis (Hostounský & Weiser, 1975) n. comb. is compared with the parasitophorous vacuole known to encase various developmental stages of several other microsporidian species.
Compartmentation and Activities of Enzymes Involved in the Metabolism of Amino Acids Implicated in Osmoregulatory Mechanisms in Acanthamoeba castellanii1
Authors: HELLEBUST JOHAN A. , LAROCHELLE JACQUES 
Published: May 2007

ABSTRACTGlutamate dehydrogenase in Acanthamoeba castellanii is an NAD‐dependent cytosolic enzyme. This is similar to glutamate dehydrogenases in Phycomycetes, but very different from the dual coenzyme‐specific enzymes located in mitochondria in animals and in mitochondria and chloroplasts in higher plants. Pyrroline‐5‐carboxylate (P‐5‐C) reductase occurs also in the cytoplasm in A. castellanii and has very high affinities for L‐P‐5‐C (Km= 12 μM) and NADH (Km= 15 μM). In contrast, ornithine aminotransferase and proline oxidase are mitochondrial enzymes. No proline‐inhibited γ‐glutamyl kinase was detected while an active glutamine synthetase was found in the cytosolic compartment. Evidence for a mitochondrial transport system for L‐proline was obtained. Two possible pathways for proline biosynthesis in A. castellanii are discussed based on information obtained about activities and subcellular compartmentation of enzymes.
Progress in Taxonomy of the Apicomplexan Protozoa
Authors: LEVINE NORMAN D. 
Published: May 2007

ABSTRACTIn 1987, 4516 species and 339 genera of the phylum Apicomplexa had been named. They consisted of the gregarines (subclass Gregarinasida) (1624 named species and 231 named genera), the hemogregarines (family Haemogregarinidae) (399 species and 4 genera), the eimeriorins (order Eimeriorida) (1771 species and 43 genera), the hemospororids (order Haemospororida) (444 species and 9 genera), the piroplasmids (order Piroplasmorida) (173 species and 20 genera), and a few others (105 species and 32 genera). The first apicomplexan protozoon was seen by Antony van Leeuwenhoek; in 1674 he saw oocysts ofEimeria stiedaiin the gall bladder of a rabbit. The first member of the phylum to be named (by Dufour in 1828) wasGregarina ovatain earwigs. During the quarter century 1826–1850, 41 species and 6 genera of Apicomplexa were named. These numbers increased progressively. In the quarter century 1951–1975, 1873 new species and 83 new genera were named. Data are given for the numbers of named species and genera of apicomplexan protozoa of each group known in 1850, 1875, 1900, 1925, 1950, 1975, and 1987.
Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia
Authors: KASIM AHMED A. , AL SHAWA YASER R. 
Published: May 2007

ABSTRACTOocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx, from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome‐shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club‐shaped, and contained two prominent refractile bodies.
Fatal Toxoplasmosis and Enteroepithelial Stages of Toxoplasma gondii in a Pallas Cat (Felis manul)1
Authors: DUBEY J. P. , GENDRON‐FITZPATRICK A. P. , LENHARD ANDREA L. , BOWMAN D. 
Published: May 2007

ABSTRACTToxoplasma gondii was found in tissues of a six‐year‐old female Pallas cat (Felis manul) from the Milwaukee County Zoo. Toxoplasma gondii meronts (types D and E), gamonts, and oocysts were present in the epithelium of the small intestine. Numerous unsporulated oocysts were present in the intestinal lumen. The cat died of acute, overwhelming toxoplasmosis. Necrotic enteritis, multifocal necrotizing granulomatous hepatitis, and pneumonia were the prominent lesions.
Effects of Cold and Nocodazole Treatments on the Microtubular Systems of Paramecium in Interphase
Authors: TORRES ANTONIO , DELGADO PILAR 
Published: May 2007

ABSTRACTThe sensitivity of the microtubular systems to cold and nocodazole treatments as well as the cellular distribution of microtubules containing acetylated a‐tubulin have been studied in Paramecium. Our results indicate that the microtubular systems of Paramecium show marked differences in stability. Cold and nocodazole treatments produce the depolymerization of the major part of the cytoplasmic microtubular network while the cortical structures remain stable under treatment. This differential stability of the microtubular systems is associated with the acetylation of the a‐tubulin. The use of the antibody 6‐11B‐1, specific for acetylated α‐tubulin, shows that the microtubular systems containing acetylated a‐tubulin are the same as those that remain stable after depoly‐merizing treatments. Finally, the images obtained during the repolymerization by heating suggest that the cortical dikinetids are able to nucleate the microtubules of the cytoplasmic network.
Development of Edhazardia aedis (Kudo, 1930) N. G., N. Comb. (Microsporida: Amblyosporidae) in the Mosquito Aedes aegypti (L.) (Diptera: Culicidae)
Authors: BECNEL JAMES J. , SPRAGUE VICTOR , FUKUDA TOKUO , HAZARD EDWIN I. 
Published: May 2007

ABSTRACTA microspondium of the mosquito Aedes aegypti (L.), identified as Nosema aedis Kudo, 1930, was found to be a heterosporous species with 3 sporulation sequences. Usually, I sequence developed in a parental generation host individual that was infected per os as a larva and the other 2 developed concurrently in a filial host larva that was infected transovarially. Under some conditions there were deviations from the parental host‐filial host alternation. The 1st sporulation sequence was diplokaryotic (diploid in a particular sense) throughout; the other 2 arose from diplokaryotic meronts, developed concurrently and ended with haploid spores. Haplosis in 1 case was by means of dissociation of the diplokaryon. In the other case it was by meiosis. Conflicting reports about whether the members of the diplokaryon in the latter sequence separate and undergo meiosis individually or coalesce and undergo meiosis as I nucleus were resolved in favor of the latter idea. A new genus in family Amblyosporidae was created to contain this species. which then became Edhazardia aedis (Kudo. 1930) n. g., n. comb.