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Al-Kappany YM Rajendran C Ferreira LR Kwok OC Abu-Elwafa SA Hilali M Dubey JP 《The Journal of parasitology》2010,96(6):1115-1118
Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 158 feral cats from Giza, Egypt, were examined for T. gondii infection. Antibodies to T. gondii were found in 97.4% with the modified agglutination test. Viable T. gondii was isolated from tissues (brain, heart, tongue) of 115 of 137 cats by bioassay in mice. These isolates were designated TgCatEg 1-115; none of these isolates was virulent to out-bred Swiss Webster mice. Of the 112 seropositive cats whose tissues were bioassayed individually, T. gondii was isolated from the hearts of 83 (74.1%), tongues of 53 (47.3%), and brains of 36 (32.1%). Toxoplasma gondii oocysts were not detected in rectal contents of any of the 158 cats, probably related to high seropositivity (chronic infection) of cats surveyed. The high prevalence of T. gondii in feral cats in Egypt reported here indicates a high environmental contamination with oocysts. 相似文献
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Sohrab?P?Shah David?YM?He Jessica?N?Sawkins Jeffrey?C?Druce Gerald?Quon Drew?Lett Grace?XY?Zheng Tao?Xu BF?Francis?OuelletteEmail author 《BMC bioinformatics》2004,5(1):40
Background
We present Pegasys – a flexible, modular and customizable software system that facilitates the execution and data integration from heterogeneous biological sequence analysis tools. 相似文献4.
Hernández Pérez A E Cerna Chávez JC Delgado Ortiz M Beltrán Beache LM Tapia Vargas YM Ochoa Fuentes 《Phyton》2019,88(1):11-13
Mexico is the main producer, consumer and exporter
of avocado in the world, being Michoacan the main producer state
contributing more than 80% of the national production. There
are phytopathogens that decimate the production causing the
death of the tree. Root samples were collected in avocado trees
that showed the characteristic symptomatology of the disease
known as avocado sadness, the sampling was carried out in four
of the main avocado producing towns, in the state of Michoacan,
Mexico. The isolation consisted in sowing root tissue in Petri
dishes with V8®-PARPH culture medium, subsequently they were
identified morphologically and for species level it was determined
by molecular biology, with the PCR-ITS technique. Pathogenicity
tests were performed in triplicate with avocado seedlings with more
than six leaves. After 24 hours, the inoculated plants expressed
decay in the apical part, after 120 hours the leaves showed yellowing
and after 15 days there was a generalized wilt on the stem and
leaves, re-isolating the phytopathogen Phytopythium vexans.
This study confirms the first report of the oomycete P. vexans
affecting avocado trees in the most important producing region of
the Mexican Republic. 相似文献
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Al-Kappany YM Lappin MR Kwok OC Abu-Elwafa SA Hilali M Dubey JP 《The Journal of parasitology》2011,97(2):256-258
Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLv) are related to human immunodeficiency virus and human leukemia virus, respectively, and these viruses are immunosuppressive. In the present study, the prevalence of antibodies to T. gondii , Bartonella spp., FIV, as well as FeLv and Dirofilaria immitis antigens was determined in sera from feral cats (Felis catus) from Cairo, Egypt. Using a modified agglutination test, antibodies to T. gondii were found in 172 (95.5%) of the 180 cats with titers of 1∶5 in 9, 1∶10 in 9, 1∶20 in 3, 1∶40 in 5, 1∶80 in 5, 1∶160 in 15, 1∶320 in 22, and 1∶640 or higher in 104. Thus, 57.4% had high T. gondii titers. Antibodies to Bartonella spp. were found in 105 (59.6%) of 178, with titers of 1∶64 in 45, 1∶128 in 39, 1∶256 in 13, 1∶512 in 3, 1∶1,024 in 4, and 1∶2,048 in 1 cat. Antibodies to FIV were detected in 59 (33.9%) of 174 cats. Of 174 cats tested, antigens to FeLv, and D. immitis were detected in 8 (4.6%) and 6 (3.4%) cats, respectively. The results indicate a high prevalence of T. gondii, Bartonella spp., and FIV infections in cats from Cairo, Egypt. This is the first report of Bartonella spp., and D. immitis infection in cats in Egypt. 相似文献
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Background
RNA exhibits a variety of structural configurations. Here we consider a structure to be tantamount to the noncrossing Watson-Crick and G-U-base pairings (secondary structure) and additional cross-serial base pairs. These interactions are called pseudoknots and are observed across the whole spectrum of RNA functionalities. In the context of studying natural RNA structures, searching for new ribozymes and designing artificial RNA, it is of interest to find RNA sequences folding into a specific structure and to analyze their induced neutral networks. Since the established inverse folding algorithms, RNAinverse, RNA-SSD as well as INFO-RNA are limited to RNA secondary structures, we present in this paper the inverse folding algorithm Inv which can deal with 3-noncrossing, canonical pseudoknot structures. 相似文献7.
Al-Kappany YM Rajendran C Abu-Elwafa SA Hilali M Su C Dubey JP 《The Journal of parasitology》2010,96(6):1112-1114
Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 115 viable T. gondii isolates from tissues of cats from Egypt were genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and DNA from tachyzoites. Seven genotypes were recognized including the clonal Type II, Type III (2 genotypes), and 4 atypical genotypes. Ninety percent (103 of 115) of isolates were clonal, i.e., Type II (n = 61) and Type III (n = 42) strains. Of the 61 Type II strains, all had the Type II alleles at all loci, except for 2 strains that had allele I at Apico. Eight isolates were divided into 4 atypical genotypes. One of these genotypes (with 4 isolates) was previously reported in dogs from Sri Lanka and in sand cats from the United Arab Emirates. Four isolates had mixed infections. These results revealed a strong clonal population structure with the dominance of clonal Type II and III lineages of T. gondii in feral cats from Egypt. 相似文献
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Spermatogenic cells of the prepuberal mouse: isolation and morphological characterization 总被引:62,自引:6,他引:56 下载免费PDF全文
AR Bellve JC Cavicchia CF Millette DA O'Brien YM Bhatnagar M Dym 《The Journal of cell biology》1977,74(1):68-85
A procedure is described which permits the isolation from the prepuberal mouse testis of highly purified populations of primitive type A spermatogonia, type A spermatogonia, type B spermatogonia, preleptotene primary spermatocytes, leptotene and zygotene primary spermatocytes, pachytene primary spermatocytes and Sertoli cells. The successful isolation of these prepuberal cell types was accomplished by: (a) defining distinctive morphological characteristics of the cells, (b) determining the temporal appearance of spermatogenic cells during prepuberal development, (c) isolating purified seminiferous cords, after dissociation of the testis with collagenase, (d) separating the trypsin-dispersed seminiferous cells by sedimentation velocity at unit gravity, and (e) assessing the identity and purity of the isolated cell types by microscopy. The seminiferous epithelium from day 6 animals contains only primitive type A spermatogonia and Sertoli cells. Type A and type B spermatogonia are present by day 8. At day 10, meiotic prophase is initiated, with the germ cells reaching the early and late pachytene stages by 14 and 18, respectively. Secondary spermatocytes and haploid spermatids appear throughout this developmental period. The purity and optimum day for the recovery of specific cell types are as follows: day 6, Sertoli cells (purity>99 percent) and primitive type A spermatogonia (90 percent); day 8, type A spermatogonia (91 percent) and type B spermatogonia (76 percent); day 18, preleptotene spermatocytes (93 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent). 相似文献