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1.
Maritza Munoz Gene Estes Michael Kilpatrick Arthur Di Salvo Gabriel Virella 《Mycopathologia》1980,72(1):47-53
The serology of candidiasis is complicated by the use of poorly defined antigens. Total extracts of the yeast phase have been commonly used as cytoplasmic antigen, without regard to the significant amounts of carbohydrate that may contaminate such preparations. This is particularly true in the case of commercially available antigens that have been used as cytoplasmic antigens but actually are richer in carbohydrate than in protein. Affinity chromatography in concanavalin A — Sepharose provides a simple procedure to separate carbohydrates, mainly mannan, from protein antigens in whole Candida extracts. By using mannan-poor antigens, the specificity of serological reactions can be increased considerably, since both the positive reactions seen in asymptomatic donors and the cross-reactions seen in patients infected with other fungi are due to anti-mannan antibodies. In contrast, both anti-mannan and anti-cytoplasmic antigen antibodies can be detected in patients suspected of systemic candidiasis. On the other hand, absolute specificity may never be achieved for systemic candidiasis. We have found antibodies against cytoplasmic antigen in a patient allergic to C. albicans, in whom the microorganism was isolated from fecal material. It appears that, under favorable conditions, mucosal sensitization may also trigger a systemic reaction directed against both mannan and cytoplasmic antigens.Publication no. 341 from The Department of Basic and Clinical Immunology and Microbiology, Medical University of South Carolina. 相似文献
2.
Ovatifolin and two new sesquiterpene lactones, deacetylovatifolin and arturin (1β-hydroxy-8β-angeloyloxy-eudesmane-4(15),11(13)-diene-6α,12-olide, have been isolated from stems and leaves of Podanthus mitiqui. Two of these compounds showed cytotoxic activity. 相似文献
3.
Chong-Pérez B Kosky RG Reyes M Rojas L Ocaña B Tejeda M Pérez B Angenon G 《Journal of biotechnology》2012,159(4):265-273
Selectable marker genes are indispensable for efficient production of transgenic events, but are no longer needed after the selection process and may cause public concern and technological problems. Although several gene excision systems exist, few have been optimized for vegetatively propagated crops. Using a Cre-loxP auto-excision strategy, we obtained transgenic banana plants cv. Grande Naine (Musa AAA) devoid of the marker gene used for selection. We used T-DNA vectors with the cre recombinase gene under control of a heat shock promoter and selectable marker gene cassettes placed between two loxP sites in direct orientation, and a gene of interest inserted outside of the loxP sites. Heat shock promoters pGmHSP17.6-L and pHSP18.2, from soybean and Arabidopsis respectively, were tested. A transient heat shock treatment of primary transgenic embryos was sufficient for inducing cre and excising cre and the marker genes. Excision efficiency, as determined by PCR and Southern hybridization was 59.7 and 40.0% for the GmHSP17.6-L and HSP18.2 promoters, respectively. Spontaneous excision was not observed in 50 plants derived from untreated transgenic embryos. To our knowledge this is the first report describing an efficient marker gene removal system for banana. The method described is simple and might be generally applicable for the production of marker-free transgenic plants of many crop species. 相似文献
4.
Ann Buchanan Josué Díaz-Delgado Gaya Balamayooran Maritza Anguiano Kátia Groch Lana Krol 《Journal of medical primatology》2020,49(6):341-343
Hematopoietic neoplasia other than lymphoma and leukemia is uncommon among non-human primates. Herein, we provide the first evidence of occurrence of leukemic histiocytic sarcoma in a captive common squirrel monkey with Saimiriine Gammaherpesvirus 2 (Rhadinovirus), Saimiri sciureus lymphocryptovirus 2 (Lymphocryptovirus), and Squirrel monkey retrovirus (β-Retrovirus) coinfection. 相似文献
5.
Nelson A. Araujo Alberto Guevara María A. Lorenzo Maritza Calabokis José Bubis 《The protein journal》2016,35(4):247-255
The cAMP-dependent protein kinase (PKA) is the best understood member of the superfamily of serine–threonine protein kinases and is involved in controlling a variety of cellular processes. Measurements of PKA activity traditionally relied on the use of [32P]-labeled ATP as the phosphate donor and a protein or peptide substrate as the phosphoaceptor. Recently non-isotopic assays for the PKA have been developed and this paper presents an improvement of a fluorometric assay for measuring the activity of PKA. Three peptides were synthesized with the following sequences: LRRASLG (Kemptide), LRRASLGK (Kemptide-Lys8) and LRRASLGGGLRRASLG (Bis-Kemptide), these have in common the substrate sequence recognized by the PKA (RRXS/TΨ), where X is any amino acid and Ψ is a hydrophobic amino acid. Optimal conditions were established for the non-radioactive assay to detect the PKA activity by phosphorylation of these three peptides that are covalently linked to fluorescamine at their N-terminus. The phosphorylated and non-phosphorylated peptides were easily separated by electrophoresis, identified and quantified with optical densitometry and ultraviolet light. The fluorescamine-labeled Kemptide-Lys8 substrate (Fluram-Kemptide-Lys8) was used to calculate the Km and Vmax of the catalytic subunit of PKA from pig heart and showed a detection limit of 260 pmol, a linear range between 700 and 1150 pmol with a linear regression R 2 = 0.956. 相似文献
6.
Yellow leaf syndrome modifies the composition of sugarcane juices in polysaccharides, phenols and polyamines 总被引:1,自引:0,他引:1
Blanca Fontaniella Carlos Vicente María Estrella Legaz Roberto de Armas Carlos Walfrido Rodríguez Maritza Martínez Dolores Pin Ricardo Acevedo María Teresa Solas 《Plant Physiology and Biochemistry》2003,41(11-12):1027-1036
Some ultrastructural changes can be observed in diseased Saccharum officinarum L. (cv. Cuba 120-78) plants with visual symptoms of yellow leaf syndrome (YLS), used to discriminate between healthy and diseased plants. Abaxial epidermis of diseased leaves shows a large amount of adhered superficial bodies, which partially occluded some stomata. Bundle sheath cells surrounding the bottom of phloem of diseased leaves are separated from the conducting tissues by a large layer of an amorphous matrix similar to wax. Debris of the end wall can be observed in large xylem vessels. Sometimes, spherical bodies similar to phytoplasma can be observed in the intercellular spaces of bundle sheath cells. These particles have never been observed in healthy plants. YLS was also associated to an increase of the concentration of reducing sugars, glucose index, and glycoproteins recovered in juices whereas the amount of sucrose decreases. Sugarcane juices obtained from both healthy and YLS-affected Cuba 120-78 cultivars of sugarcane contained putrescine (PUT), cadaverine (CAD), spermidine and spermine (SPM) as free and macromolecules-conjugated compounds. Only CAD and SPM appeared as acid-soluble conjugates to small molecules whereas PUT and CAD are the major polyamines (PAs) conjugated to macromolecules, mainly to high molecular mass glycoproteins. The disease was associated to an increase in total PA fraction. Arginase and ornithine decarboxylase activities, responsible for the synthesis of PUT, were higher in YLS juices than in those obtained from healthy plants. CAD and SPM presumably conjugated mostly to chlorogenic, syringic and ferulic acids in juices from YLS plants. 相似文献
7.
Galán-Caridad JM Calabokis M Uzcanga G Aponte F Bubis J 《Memórias do Instituto Oswaldo Cruz》2004,99(8):845-854
Trypanosoma evansi contains protein kinases capable of phosphorylating endogenous substrates with apparent molecular masses in the range between 20 and 205 kDa. The major phosphopolypeptide band, pp55, was predominantly localized in the particulate fraction. Anti-alpha and anti-beta tubulin monoclonal antibodies recognized pp55 by Western blot analyses, suggesting that this band corresponds to phosphorylated tubulin. Inhibition experiments in the presence of emodin, heparin, and 2,3-bisphosphoglycerate indicated that the parasite tubulin kinase was a casein kinase 2 (CK2)-like activity. GTP, which can be utilized instead of ATP by CK2, stimulated rather than inactivated the phosphorylation of tubulin in the parasite homogenate and particulate fraction. However, GTP inhibited the cytosolic CK2 responsible for phosphorylating soluble tubulin and other soluble substrates. Casein and two selective peptide substrates, P1 (RRKDLHDDEEDEAMSITA) for casein kinase (CK1) and P2 (RRRADDSDDDDD) for CK2, were recognized as substrates in T. evansi. While the enzymes present in the soluble fraction predominantly phosphorylated P1, P2 was preferentially labeled in the particulate fractions. These results demonstrated the existence of CK1-like and CK2-like activities primarily located in the parasite cytosolic and membranous fractions, respectively. Histone II-A and kemptide (LRRASVA) also behaved as suitable substrates, implying the existence of other Ser/Thr kinases in T. evansi. Cyclic AMP only increased the phosphorylation of histone II-A and kemptide in the cytosol, demonstrating the existence of soluble cAMP-dependent protein kinase-like activities in T. evansi. However, no endogenous substrates for this enzyme were identified in this fraction. Further evidences were obtained by using PKI (6-22), a reported inhibitor of the catalytic subunit of mammalian cAMP-dependent protein kinases, which specifically hindered the cAMP-dependent phosphorylation of histone II-A and kemptide in the parasite soluble fraction. Since the sum of the values obtained in the parasite cytosolic and particulate fractions were always higher than the values observed in the total T. evansi lysate, the kinase activities examined here appeared to be inhibited in the original extract. 相似文献
8.
Jaramillo M Gowda DC Radzioch D Olivier M 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(8):4243-4253
NO overproduction has been suggested to contribute to the immunopathology related to malaria infection. Even though a role for some parasite molecules (e.g., GPI) in NO induction has been proposed, the direct contribution of hemozoin (HZ), another parasite metabolite, remains to be established. Therefore, we were interested to determine whether Plasmodium falciparum (Pf) HZ and synthetic HZ, beta-hematin, alone or in combination with IFN-gamma, were able to induce macrophage (Mphi) NO synthesis. We observed that neither Pf HZ nor synthetic HZ led to NO generation in B10R murine Mphi; however, they significantly increased IFN-gamma-mediated inducible NO synthase (iNOS) mRNA and protein expression, and NO production. Next, by investigating the transductional mechanisms involved in this cellular regulation, we established that HZ induces extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase phosphorylation as well as NF-kappaB binding to the iNOS promoter, and enhances the IFN-gamma-dependent activation of both second messengers. Of interest, cell pretreatment with specific inhibitors against either NF-kappaB or the ERK1/2 pathway blocked the HZ + IFN-gamma-inducible NF-kappaB activity and significantly reduced the HZ-dependent increase on IFN-gamma-mediated iNOS and NO induction. Even though selective inhibition of the Janus kinase 2/STAT1alpha pathway suppressed NO synthesis in response to HZ + IFN-gamma, HZ alone did not activate this signaling pathway and did not have an up-regulating effect on the IFN-gamma-induced Janus kinase 2/STAT1alpha phosphorylation and STAT1alpha binding to the iNOS promoter. In conclusion, our results suggest that HZ exerts a potent synergistic effect on the IFN-gamma-inducible NO generation in Mphi via ERK- and NF-kappaB-dependent pathways. 相似文献
9.
Vonasek E Mateu L Luzzati V Marquez G Vargas R Céspedes G Cotúa M Borges J 《European biophysics journal : EBJ》2001,30(1):11-16
A sural nerve dissected from a recently dead patient displayed an unusual X-ray diffraction pattern, suggesting that in situ and at the time of the patient's death the myelin sheaths were in a swollen state. Diffraction patterns of the swollen type were also recorded from: (1) a sural nerve from the corpse of a neurologically healthy person after soaking the nerve with Ringer solution at pH 5.5; (2) sciatic nerves dissected from rat cadavers at increasing time after death. In all the cases the swollen patterns reversed to the native type upon superfusion with Ringer solution at pH 7.3. The postmortem effect is to decrease the pH of the fluids surrounding the nerves in the cadavers. Our experiments show that the early postmortem processes have the effect of acidifying PNS nerves and that as a consequence of acidification the myelin sheaths swell. 相似文献
10.
Carey E. Gleason N. Maritza Dowling Whitney Wharton JoAnn E. Manson Virginia M. Miller Craig S. Atwood Eliot A. Brinton Marcelle I. Cedars Rogerio A. Lobo George R. Merriam Genevieve Neal-Perry Nanette F. Santoro Hugh S. Taylor Dennis M. Black Matthew J. Budoff Howard N. Hodis Frederick Naftolin S. Mitchell Harman Sanjay Asthana 《PLoS medicine》2015,12(6)