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1.
SYNOPSIS. Babesiosoma ophicephali n. sp. (Babesiidae; Haemosporidia), from the red blood cells of the freshwater teleost fish Ophicephalus punctatus Bloch, collected from suburbs of Calcutta, is described. Giemsa-stained films of blood from the caudal region of 20 fishes were examined, and 2 fishes were found to be infected. The genus Babesiosoma is described for the first time in India. The systematic position of the parasite is discussed in detail.  相似文献   

2.
Sanguilevator yearsleyi n. gen., n. sp. and Cathetocephalus resendezi n. sp. are described from the Broadfin shark, Lamiopsis temmincki, in Malaysian Borneo and Carcharhinus leucas in Mexico, respectively. The new genus is unusual in its possession of internal chambers and channels in its scolex that appear to house extensive quantities of host white and red blood cells, respectively. Histology reveals an extremely intimate association between host tissue and the surface of the apical pad of the scolex. Positive staining with periodic acid-Schiff of the surface of the pad of the scolex and the linings of the chambers and channels suggests that an adhesive substance may be produced in these regions. However, explanations for how and why host blood cells come to reside within the scolex remain elusive. Cathetocephalus resendezi n. sp. is distinctive in the form of the papillae in the papillate band of the scolex and also in the inconspicuous nature of the rugose base of the scolex. Scanning electron microscopy of both new taxa as well as Cathetocephalus thatcheri, Cathetocephalus australis and an undescribed species of Cathetocephalus collected from Carcharhinus amboinensis in Australia, suggests that the papillae surrounding the pad of the scolex are of significant taxonomic utility in distinguishing among species in these groups. Parsimony and Bayesian analyses of sequence data (766 bases of 18S rDNA and 405 bases of 28S rDNA) generated from ethanol preserved specimens of C. thatcheri and S. yearsleyi, when compared with equivalent data available for 40 cestode species in GenBank, resulted in trees that support previous propositions that Cathetocephalus should be placed in the order Cathetocephalidea. The results suggest that Sanguilevator should also be considered to belong to this order.  相似文献   

3.
Sphaerospora epinepheli n. sp. is described from grouper, Epinephelus malabaricus, in cage-cultured and wild fish collected from both coastal lines of southern Thailand. Subspherical to spherical spores and mono- or disporous pseudoplasmodia were observed in the lumen of kidney tubules. Pseudoplasmodia were round to elongate, size range 15.6-22.9 microns (length) x 8.4-21.6 microns (width). Spores were 7.8-10.0 microns (length) x 12.3-14.5 microns (thickness), and 7.0-9.5 microns (width) with two spherical polar capsules of equal size measuring 2.9-4.4 microns in diameter and containing polar filaments with six or seven windings. Two uninucleate sporoplasms showed iodine vacuoles. Blood stages, similar to C-blood protozoans observed from freshwater fish in Europe, were found from peripheral blood smears of grouper. Ultrastructural studies of blood stages showed a similar structure to unidentified mobile protozoans from the blood of carp. Electron dense bodies were observed in the cytoplasm of the primary cell blood stages. Infected proximal-tubular epithelial cells showed highly vacuolated cytoplasm and pycnotic nuclei.  相似文献   

4.
SYNOPSIS. The blood of each of 95 turtles (8 species) collected from southeastern Louisiana was infected with some or all of the merogonic stages and gametocyte stage of Haemogregarina pseudemydis n. sp. Five species of turtles harbored Pirhemocyton chelonarum n. sp. Turtle Haemogregarina and Pirhemocyton are locality records for Louisiana. Pirhemocyton is reported for the first time in turtles and in the continental U.S.A.  相似文献   

5.
Trypanosoma kansasensis sp. n. (Sarcomastigophora: Kinetoplastida) is described from three of 23 (13%) eastern woodrats (Neotoma floridana) collected from Pottawatomie County, Kansas (USA). All flagellates found in the blood of woodrats were trypomastigotes and are larger than T. neotomae in overall dimensions, especially flagellar length and the distance between the posterior end of the organism and kinetoplast. Liver infusion-tryptose (LIT) cultures of infected whole blood resulted in the transformation of some parasites into epimastigotes; however, there was no apparent increase in parasite numbers.  相似文献   

6.
The expansion of trinucleotide repeats has been implicated in 17 neurological diseases to date. Factors leading to the instability of trinucleotide repeat sequences have thus been an area of intense interest. Certain genes involved in mismatch repair, recombination, nucleotide excision repair, and replication influence the instability of trinucleotide repeats in both Escherichia coli and yeast. Using a genetic assay for repeat deletion in E. coli, the effect of mutations in the recA, recB, and lexA genes on the rate of deletion of (CTG)n.(CAG)n repeats of varying lengths were examined. The results indicate that mutations in recA and recB, which decrease the rate of recombination, had a stabilizing effect on (CAG)n.(CTG)n repeats decreasing the high rates of deletion seen in recombination proficient cells. Thus, recombination proficiency correlates with high rates of genetic instability in triplet repeats. Induction of the SOS system, however, did not appear to play a significant role in repeat instability, nor did the presence of triplet repeats in cells turn on the SOS response. A model is suggested where deletion during exponential growth may result from attempts to restart replication when paused at triplet repeats.  相似文献   

7.
8.
Bisbalia vossi n. g., n. sp. is described from Heteromys anomalus (Rodentia: Geomyoidea: Heteromyidae) in northern Venezuela (Aragua). The filariae were found in a membranous pocket in the pleural cavity, and almost all had ingested red blood cells of their host. The morphology of this onchocercine species is highly evolved (advanced reduction of head and caudal papillae; short undivided oesophagus). Its very short microfilariae (60 m) and the shape of the tail of the female (two terminal median pairs of bosses) suggest that this species could be derived from Ackertia Vaz, 1934, a South American genus parasitic in caviomorph rodents which is related to the Dipetalonema-line, but Ackertia has several pairs of precloacal papillae, which are absent in the new genus. In North America, where the geomyoid rodents originated and diversified, the two previously described filarial species differ from this new material and show affinities with Old World bat parasites (Litomosa van Beneden, 1871).  相似文献   

9.
The objective of this study was to investigate, using a pulse-chase technique, the different incorporation of (1-(14)C) n -9, n -6 and n 3 fatty acids into hepatoma lipids and their secretion to the culture medium. Docosahexaenoic acid (DHA) accumulated preferentially into the triacylglycerol while arachidonic acid (AA) did into the phospholipid fraction. DHA was poorly secreted to the culture medium whereas AA was secreted to a large extent. The fatty acids were initially esterified mainly into phosphatidylcholine and phosphatidylethanolamine. During the 24 h chase, a general shift from phosphatidylcholine to phosphatidylethanolamine was observed. Linoleic acid was esterified in cardiolipin to a much greater extent than any other fatty acid and it was not converted to more polyunsaturated fatty acids.The supplementation of the culture medium with polyunsaturated fatty acids had no inhibitory effect on the growth of the hepatoma cells, in marked contrast to observations made in other tumoral cells. The reasons for the resistance of the hepatoma cells to polyunsaturated fatty acid toxicity, including the possible antioxidant effect of linoleic acid accumulation in cardiolipin, are also discussed.  相似文献   

10.
Malawimonas jakobiformis n. gen., n. sp., is established for a bacterivorous heterotrophic nanoflagellate isolated from the Malawi shore of Lake Nyasa (eastern Africa). Trophic stages observed were anteriorly biflagellate and naked. The posterior flagellum of a trophic cell resided in a conspicuous groove on the ventral surface, and bore a prominent vane. A Golgi stack and a mitochondrion with discoidal cristae were present anterior to the nucleus. The kinetid consisted of two short, slightly separated basal bodies, four microtubular roots, and associated fibers and bands. The three microtubular roots associated with the posterior basal body were associated with the ventral groove, while the single root associated with the anterior basal body gave rise to secondary cytoskeletal microtubules. Dividing cells became rounded, with persistent flagella. Cysts were uninucleate, and had thin organic walls without clearly differentiated apertures or ornamentation but with conspicuous attachment pads. Kinetid elements were present within cysts. On the basis of microscopical features, especially those of the kinetid, the nearest relatives of M. jakobiformis are the mitochondriate “jakobid” protists (families Histionidae and Jakobidae) and the amitochondriate retortamonads. Malawimonadidae n. fam. is established to accommodate this species.  相似文献   

11.
Interruption of the (I)n strand of (I)n.(C)n by unpaired bases [(U)] yielded mismatched analogues, (Ix,U)n.(C)n which were still effective as inducers of interferon, provided the I:U ratio (x) was equal or greater than 10. In highly sensitive interferon-induction systems such as primary rabbit kidney cells and human skin fibroblasts superinduced with cycloheximide and actinomycin D, (I10,U)n.(C)n and (I50,U)n.(C)n proved nearly as active as (I)n.(C)n. By virtue of their increased susceptibility to degradation by nucleases, (Ix,U)n.(C)n complexes with 10 less than or equal to x less than or equal to 50 may be expected not to persist as long in biological fluids as (I)n.(C)n, hence to induce fewer side effects.  相似文献   

12.
Caryospora cheloniae sp. n. is described from mariculture-reared green sea turtles (Chelonia m. mydas). The sporulated oocyst has a thin, transparent, single-layered wall which often ruptures, leaving a naked sporulated sporocyst. Oocysts measured 33.8 to 40.1 micrometer by 11.0 to 14.6 micrometer (mean 37.4 by 12.8 micrometer). Greatest concentrations of developmental stages of C. cheloniae were found in the hindgut. Transverse binary fission was observed in dividing tissue stages. Pathologic alterations were most pronounced in the posterior third of the intestines (hindgut). The hindgut lumen was greatly dilated and filled with blood, oocysts and tissue debris. The hindgut wall was thinner than normal and the mucosal folds had sloughed into the intestinal lumen. Free blood escaped from the blood vessels of the tunica propria into the intestinal lumen. Epithelial hyperplasia was pronounced at the margins of denuded mucosal areas. Numerous inflammatory cells infiltrated the infected mucosal surface.  相似文献   

13.
We hypothesized that reduction/loss of very long chain PUFAs (VLC-PUFAs) due to mutations in the ELOngase of very long chain fatty acid-4 (ELOVL4) protein contributes to retinal degeneration in autosomal dominant Stargardt-like macular dystrophy (STGD3) and age-related macular degeneration; hence, increasing VLC-PUFA in the retina of these patients could provide some therapeutic benefits. Thus, we tested the efficiency of elongation of C20-C22 PUFA by the ELOVL4 protein to determine which substrates are the best precursors for biosynthesis of VLC-PUFA. The ELOVL4 protein was expressed in pheochromocytoma cells, while green fluorescent protein-expressing and nontransduced cells served as controls. The cells were treated with 20:5n3, 22:6n3, and 20:4n6, either individually or in equal combinations. Both transduced and control cells internalized and elongated the supplemented FAs to C22-C26 precursors. Only ELOVL4-expressing cells synthesized C28-C38 VLC-PUFA from these precursors. In general, 20:5n3 was more efficiently elongated to VLC-PUFA in the ELOVL4-expressing cells, regardless of whether it was in combination with 22:6n3 or with 20:4n6. In each FA treatment group, C34 and C36 VLC-PUFAs were the predominant VLC-PUFAs in the ELOVL4-expressing cells. In summary, 20:5n3, followed by 20:4n6, seems to be the best precursor for boosting the synthesis of VLC-PUFA by ELOVL4 protein.  相似文献   

14.
The Bothrops neuwiedi (Neuwied's lancehead) species complex consists of a variety of subspecies with a wide distribution in South America. In this work, we compared the neuromuscular blockade caused by venoms from three subspecies (B. n. goyazensis, B. n. paranaensis and B. n. diporus) of this complex using chick biventer cervicis (BC) and mouse phrenic nerve-diaphragm (PND) preparations and investigated their phospholipase A2 (PLA2) activities and electrophoretic profiles. The order of potency of PLA2 activity was B. n. diporus>B. n. paranaensis>B. n. goyazensis. In BC preparations, B. n. goyazensis venom (50 microg/mL) was significantly (p<0.05) more active than B. n. paranaensis and B. n. diporus venoms, which did not produce a significant blockade at this time interval; after 120 min, B. n. goyazensis, B. n. paranaensis and B. n. diporus venoms (100 microg/mL) produced blockades of 57.4+/-5%, 30+/-3% and 17.4+/-7% (n=3-6 each), respectively. The three venoms inhibited contractures in response to ACh, indicating interference with postsynaptic neurotransmission. Only B. n. goyazensis and B. n. paranaensis venoms caused a long-lasting, concentration-dependent muscle contracture prior to blockade. In PND preparations, all of the venoms blocked the twitch-tension responses within 45-100 min, indicating that these preparations were more sensitive than avian preparations. There was a correlation between PLA2 activity and the time for 50% blockade in PND but not in BC preparations. SDS-PAGE showed quantitative rather than qualitative differences among the venoms. These results indicate that the venoms of the three subspecies had similar profiles of neuromuscular activity, although the relationship with PLA2 activity varied with the preparation used.  相似文献   

15.
When discussing the rheological properties of normal and leukemic blood it must be considered that blood is a suspension of cells in aqueous solution which is also known as plasma. Whole blood viscosity and plasma viscosity were determined by Rheometer LS30 which allows measuring whole blood and plasma viscosity in the middle and low shear rate ranges. The measurements of the viscosity showed that whole blood and plasma behave as non-Newtonian power law fluid. The values of n (non-Newtonian index) and k (consistency index) of power law fluid were calculated for both leukemic blood and plasma samples. The importance of this phenomenon for the micro-circulation is discussed.  相似文献   

16.
Leishmania herreri sp. n. is described after isolation in pure culture from blood, viscera and skin of two-toed (Choloepus hoffmanni) and three-toed (Bradypus griseus) sloths from Costa Rica. Also, it was isolated from the following sandflies: Lutzomyia trapidoi, L. ylephiletor and L. shannoni. The amastigote forms were not seen in the final hosts but they were obtained in tissue culture at 33 C. Both promastigotes and amastigotes failed to infect hamsters. The new parasite is isolated frequently in culture, mixed with other hemoflagellates such as L. braziliensis, Endotrypanum sp. and Trypanosoma rangeli.  相似文献   

17.
The morphology and infraciliature of a new hypotrichous ciliate, Euplotidium smalli n. sp., isolated from eutrophic coastal water in Korea, were observed in living cells and investigated using the protargol impregnation technique. This new ciliate bears 13-14 frontoventral cirri, 7 transverse cirri, and 5-6 dorsal kineties. Neither left marginal cirrus nor caudal cirrus is present. The new species differs from the related species, Euplotidium agitatum Noland, 1937 in the different number of frontoventral and transverse cirri and different body shape. With the exception of Euplotidium agitatum, the known species of the genus Euplotidium Noland, 1937 with the presence of left marginal cirrus are assigned to a new genus, Paraeuplotidium n. g. Diagnosis of Paraeuplotidium is: Gastrocirrhidae with funnel-shaped buccal cavity; with frontoventral and transverse cirri; left marginal cirrus present. Paraeuplotidium itoi (Ito, 1958) n. comb. is designated here the type species. Four additional species are included: Paraeuplotidium psammophilus (Vacelet, 1961) n. comb., Paraeuplotidium arenarium (Magagnini & Nobili, 1964) n. comb., Paraeuplotidium helgae (Hartwig, 1980) n. comb., and Paraeuplotidium prosaltans (Tuffrau, 1985) n. comb. An improved generic diagnosis of Euplotidium is suggested based on morphology and infraciliature characters: marine hypotrichs with a funnel-shaped buccal cavity; with frontoventral and transverse cirri; neither left marginal cirrus nor caudal cirri present.  相似文献   

18.
Four new eimerian species are described from red-backed voles, Clethrionomys gapperi in Pennsylvania. Sporulated oocysts of Eimeria clethrionomyis sp. n. are ellipsoidal, 18.8 (16.5-21.5) x 14.9 (14.0-16.5) with elongate, ovoid sporocysts, 10.6 (9.5-12.0) x6.1 (5.5-7.0). The oocyst wall is smooth, with 2 layers, and thins, with terminal cap at one or both ends. Polar granules, dark Stieda body and sporocyst residuum are present. The oocyst residuum is absent. Sporulated oocysts of Eimeria gallatii sp. n. are ellipsoidal, 27.7 (21-32) x 19.3 (17-24) with ovoid sporocysts, 13.5 (12-15) x 8.8 (8-10). The oocyst wall is smooth, 2-layered, with a micropyle and thin wall at the end opposite the micropyle. Polar granules, Stieda body and sporocyst residuum are present. The oocyst residuum is atypical, of cobwebby material. Sporulated oocysts of Eimeria pileata sp. n. are subspherical to spherical, 25.2 (20.5-29.5) x 22.5 (19.5-25.5) with ellipsoidal sporocysts, 13.4(10.5-15.0) x 8.4 (7.5-9.5). The oocyst wall is rough, pitted, striated, 2-layered, with no micropyle. Polar granules, oocyst and sporocyst residuum, Stieda body and stiedal cap are present. Sporulated oocysts of Eimeria marconii sp. n. are ellipsoidal, 13.0 (10.5-15-0) x 10.6 (9.5-12.0) with elongate, ovoid sporocysts, 7.7 (7.0-8.5) x 4.2 (3.0-4.5). The oocyst wall is smooth, single-layered, with no micropyle. Polar granules, dark Stiedal body and sporocyst residuum are present. There is no oocyst residuum.  相似文献   

19.
The planktonic ciliate Parastrombidinopsis shimi n. gen., n. sp. is described from both living cells and quantitative protargol-stained (QPS) preparations and the sequence of the small subunit rDNA (SSU rDNA) is reported. This species is almost oval when the cells are alive; when stained, it is cylindrical for the upper two-fifths, half-bowl shaped for the middle two-fifths, and narrow rodshaped for the lower one-fifth. The ranges (and mean +/- standard deviation, n = 20) of cell length, cell width, and oral diameter of living cells were 112-221 microm (168 +/- 39), 88-176 microm (121 +/- 30), and 53-110 microm (80 +/- 14), respectively, while those of the QPS-stained specimens (n = 54) were 88-225 microm (162 +/- 29), 55-163 microm (102 +/- 19), and 53-98 microm (69 +/- 9), respectively. Thirty-six to 48 external oral polykinetids had cilia 25-40 microm long. However, unlike Strombidinopsis species sensu stricto, P. shimi has an external oral polykinetid zone that is an open circle. This species has two shorter polykinetids associated with the end of the oral polykinetid zone, deep in the oral cavity. Like Strombidinopsis species in the subclass Choreotrichia, 36-50 somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 68-105 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3-10 microm long. Parastrombidinopsis shimi had 2 (1-4) ovoid macronuclei of 20-82 x 15-32 microm. When properly aligned, the sequence of the SSU rDNA of P. shimi (GenBank Accession No. AJ786648) was approximately 5% different from that of Strobilidium caudatum and 6% different from that of two Strombidinopsis species. Based both on morphology and gene sequence divergence, we establish this is as a new species in a new genus belonging to the family Strombidinopsidae.  相似文献   

20.
Abstract. Tertiapatus dominicanus n.g., n.sp. (Tertiapatidae n.fam.) and Succinipatopsis balticus n.gen., n.sp. (Succinipatopsidae n.fam.) (Lobopodia: Onychophora), the first Tertiary fossils of the Lobopodia, are described from Dominican and Baltic amber, respectively. Both families are characterized by the presence of simple legs lacking foot portions with claws and pads. Tertiapatidae is further characterized by soluble body pigments and oral papillae shorter than the legs. Succinipatopsidae is characterized by non-soluble body pigments and oral papillae longer than the legs. Nomenclatural changes include the erection of the class Udeonychophora n. nom. for terrestrial onychophorans with a ventral mouth, the order Ontonychophora n.nom. for extant onychophorans possessing legs with a differentiated "foot" portion, and the family Helenodoridae n.nom. for the genus Helenodora from the Carboniferous. The biogeographical significance of these fossils and their phylogenetic relationship with previously described onychophorans are discussed.  相似文献   

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