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Recombinant adeno-associated virus (rAAV) vectors are increasingly popular tools for gene therapy applications. Their non-pathogenic status, low inflammatory potential, availability of viral serotypes with different tissue tropisms, and prospective long-lasting gene expression are important attributes that make rAAVs safe and efficient therapeutic options. Over the last three decades, several groups have engineered recombinant AAV-producing platforms, yielding high titers of transducing vector particles. Current specific productivity yields from different platforms range from 10 to 10 vector genomes (vg) per cell, and there is an ongoing effort to improve vector yields in order to satisfy high product demands required for clinical trials and future commercialization. Crucial aspects of vector production include the molecular design of the rAAV-producing host cell line along with the design of AAV genes, promoters, and regulatory elements. Appropriately, configuring and balancing the expression of these elements not only contributes toward high productivity, it also improves process robustness and product quality. In this mini-review, the rational design of rAAV-producing expression systems is discussed, with special attention to molecular strategies that contribute to high-yielding, biomanufacturing-amenable rAAV production processes. Details on molecular optimization from four rAAV expression systems are covered: adenovirus, herpesvirus, and baculovirus complementation systems, as well as a recently explored yeast expression system. [ABSTRACT FROM AUTHOR]

The yeast Saccharomyces cerevisiae has been successfully employed to establish model systems for a number of viruses. Such model systems are powerful tools to study the virus biology and in particular for the identification and characterization of host factors playing a role in the viral infection cycle. Adeno-associated viruses (AAV) are heavily studied due to their use as gene delivery vectors. AAV relies on other helper viruses for successful replication and on host factors for several aspects of the viral life cycle. However the role of host and helper viral factors is only partially known. Production of recombinant AAV (rAAV) vectors for gene delivery applications depends on knowledge of AAV biology and the limited understanding of host and helper viral factors may be precluding efficient production, particularly in heterologous systems. Model systems in simpler eukaryotes like the yeast S. cerevisiae would be useful tools to identify and study the role of host factors in AAV biology. Here we show that expression of AAV2 viral proteins VP1, VP2, VP3, AAP, Rep78, Rep52 and an ITR-flanked DNA in yeast leads to capsid formation, DNA replication and encapsidation, resulting in formation of infectious particles. Many of the AAV characteristics observed in yeast resemble those in other systems, making it a suitable model system. Future findings in the yeast system could be translatable to other AAV host systems and aid in more efficient production of rAAV vectors. [ABSTRACT FROM AUTHOR]

RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a "matchmaker" that brings the viral p92pol replication protein and the DDX3- like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. [ABSTRACT FROM AUTHOR]

Viruses recruit cellular membranes and subvert cellular proteins involved in lipid biosynthesis to build viral replicase complexes and replication organelles. Among the lipids, sterols are important components of membranes, affecting the shape and curvature of membranes. In this paper, the tombusvirus replication protein is shown to co-opt cellular Oxysterol-binding protein related proteins (ORPs), whose deletion in yeast model host leads to decreased tombusvirus replication. In addition, tombusviruses also subvert Scs2p VAP protein to facilitate the formation of membrane contact sites (MCSs), where membranes are juxtaposed, likely channeling lipids to the replication sites. In all, these events result in redistribution and enrichment of sterols at the sites of viral replication in yeast and plant cells. Using in vitro viral replication assay with artificial vesicles, we show stimulation of tombusvirus replication by sterols. Thus, co-opting cellular ORP and VAP proteins to form MCSs serves the virus need to generate abundant sterol-rich membrane surfaces for tombusvirus replication. [ABSTRACT FROM AUTHOR]

Assembling of the membrane-bound viral replicase complexes (VRCs) consisting of viral- and host-encoded proteins is a key step during the replication of positive-stranded RNA viruses in the infected cells. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host have revealed the involvement of eleven cellular ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. The ESCRT proteins are involved in endosomal sorting of cellular membrane proteins by forming multiprotein complexes, deforming membranes away from the cytosol and, ultimately, pinching off vesicles into the lumen of the endosomes. In this paper, we show an unexpected key role for the conserved Vps4p AAA+ ATPase, whose canonical function is to disassemble the ESCRT complexes and recycle them from the membranes back to the cytosol. We find that the tombusvirus p33 replication protein interacts with Vps4p and three ESCRT-III proteins. Interestingly, Vps4p is recruited to become a permanent component of the VRCs as shown by co-purification assays and immuno-EM. Vps4p is co-localized with the viral dsRNA and contacts the viral (+)RNA in the intracellular membrane. Deletion of Vps4p in yeast leads to the formation of crescent-like membrane structures instead of the characteristic spherule and vesicle-like structures. The in vitro assembled tombusvirus replicase based on cell-free extracts (CFE) from vps4Δ yeast is highly nuclease sensitive, in contrast with the nuclease insensitive replicase in wt CFE. These data suggest that the role of Vps4p and the ESCRT machinery is to aid building the membrane-bound VRCs, which become nuclease-insensitive to avoid the recognition by the host antiviral surveillance system and the destruction of the viral RNA. Other (+)RNA viruses of plants and animals might also subvert Vps4p and the ESCRT machinery for formation of VRCs, which require membrane deformation and spherule formation. [ABSTRACT FROM AUTHOR]

RNA viruses take advantage of cellular resources, such as membranes and lipids, to assemble viral replicase complexes (VRCs) that drive viral replication. The host lipins (phosphatidate phosphatases) are particularly interesting because these proteins play key roles in cellular decisions about membrane biogenesis versus lipid storage. Therefore, we examined the relationship between host lipins and tombusviruses, based on yeast model host. We show that deletion of PAH1 (phosphatidic acid phosphohydrolase), which is the single yeast homolog of the lipin gene family of phosphatidate phosphatases, whose inactivation is responsible for proliferation and expansion of the endoplasmic reticulum (ER) membrane, facilitates robust RNA virus replication in yeast. We document increased tombusvirus replicase activity in pah1Δ yeast due to the efficient assembly of VRCs. We show that the ER membranes generated in pah1Δ yeast is efficiently subverted by this RNA virus, thus emphasizing the connection between host lipins and RNA viruses. Thus, instead of utilizing the peroxisomal membranes as observed in wt yeast and plants, TBSV readily switches to the vastly expanded ER membranes in lipin-deficient cells to build VRCs and support increased level of viral replication. Over-expression of the Arabidopsis Pah2p in Nicotiana benthamiana decreased tombusvirus accumulation, validating that our findings are also relevant in a plant host. Over-expression of AtPah2p also inhibited the ER-based replication of another plant RNA virus, suggesting that the role of lipins in RNA virus replication might include several more eukaryotic viruses. [ABSTRACT FROM AUTHOR]

Abstract: Recruited host factors aid replication of plus-strand RNA viruses. In this paper, we show that Dbp2 DEAD-box helicase of yeast, which is a homolog of human p68 DEAD-box helicase, directly affects replication of Tomato bushy stunt virus (TBSV). We demonstrate that Dbp2 binds to the 3′-end of the viral minus-stranded RNA and enhances plus-strand synthesis by the viral replicase in a yeast-based cell-free TBSV replication assay. In vitro data with wt and an ATPase-deficient Dbp2 mutant indicate that Dbp2 unwinds local secondary structures at the 3′-end of the TBSV (−)RNA. We also show that Dbp2 complements the replication deficiency of TBSV in yeast containing reduced amount of Ded1 DEAD-box helicase, another host factor involved in TBSV replication, suggesting that Dbp2 and Ded1 helicases play redundant roles in TBSV replication. We also show that the orthologous AtRH20 DEAD-box helicase from Arabidopsis can increase tombusvirus replication in vitro and in yeast. [Copyright &y& Elsevier]

Abstract: To identify new genes affecting Tomato bushy stunt virus (TBSV) replication in yeast model host, we are studying protein families, whose members have been identified during previous high throughput screening. In this paper, we have characterized the WW domain-containing protein family from yeast and plants. We find that, in addition to Rsp5 E3 ubiquitin ligase, yeast Wwm1 and Prp40 and three Arabidopsis WW domain-containing proteins are strong inhibitors of TBSV replication. The tombusvirus replicase complex isolated from yeast with down-regulated Wwm1 protein level was more active. Accumulation of viral p92pol was reduced when Wwm1 was over-expressed, suggesting that the stability of p92pol might be reduced, as observed with Rsp5. Moreover, replication of two insect RNA viruses is also inhibited by Wwm1 and Rsp5, suggesting that WW domain-containing proteins might have broad regulatory effects on RNA viruses. Thus, artificial antiviral proteins with WW domains could be useful antiviral strategy. [Copyright &y& Elsevier]

Abstract: Post-translational modifications of viral replication proteins could be widespread phenomena during the replication of plus-stranded RNA viruses. In this article, we identify two lysines in the tombusvirus p33 replication co-factor involved in ubiquitination and show that the same lysines are also important for the p33 to interact with the host Vps23p ESCRT-I factor. We find that the interaction of p33 with Vps23p is also affected by a “late-domain”-like sequence in p33. The combined mutations of the two lysines and the late-domain-like sequences in p33 reduced replication of a replicon RNA of Tomato bushy stunt virus in yeast model host, in plant protoplasts, and plant leaves, suggesting that p33-Vps23p ESCRT protein interaction affects tombusvirus replication. Using ubiquitin-mimicking p33 chimeras, we demonstrate that high level of p33 ubiquitination is inhibitory for TBSV replication. These findings argue that optimal level of p33 ubiquitination plays a regulatory role during tombusvirus infections. [Copyright &y& Elsevier]

Plus-stranded RNA viruses replicate in infected cells by assembling viral replicase complexes consisting of viral- and hostcoded proteins. Previous genome-wide screens with Tomato bushy stunt tombusvirus (TBSV) in a yeast model host revealed the involvement of seven ESCRT (endosomal sorting complexes required for transport) proteins in viral replication. In this paper, we show that the expression of dominant negative Vps23p, Vps24p, Snf7p, and Vps4p ESCRT factors inhibited virus replication in the plant host, suggesting that tombusviruses co-opt selected ESCRT proteins for the assembly of the viral replicase complex. We also show that TBSV p33 replication protein interacts with Vps23p ESCRT-I and Bro1p accessory ESCRT factors. The interaction with p33 leads to the recruitment of Vps23p to the peroxisomes, the sites of TBSV replication. The viral replicase showed reduced activity and the minus-stranded viral RNA in the replicase became more accessible to ribonuclease when derived from vps23Δ or vps24Δ yeast, suggesting that the protection of the viral RNA is compromised within the replicase complex assembled in the absence of ESCRT proteins. The recruitment of ESCRT proteins is needed for the precise assembly of the replicase complex, which might help the virus evade recognition by the host defense surveillance system and/or prevent viral RNA destruction by the gene silencing machinery. [ABSTRACT FROM AUTHOR]

To identify host proteins interacting with Tomato bushy stunt virus (TBSV) replication proteins in a genome-wide scale, we have used a yeast (Saccharomyces cerevisiae) proteome microarray carrying 4,088 purified proteins. This approach led to the identification of 58 yeast proteins that interacted with p33 replication protein. The identified host proteins included protein chaperones, ubiquitin-associated proteins, translation factors, RNA-modifying enzymes, and other proteins with yet-unknown functions. We confirmed that 19 of the identified host proteins bound to p33 in vitro or in a split-ubiquitin-based two-hybrid assay. Further analysis of Cdc34p E2 ubiquitin-conjugating enzyme, which is one of the host proteins interacting with p33, revealed that Cdc34p is a novel component of the purified viral replicase. Downregulation of Cdc34p expression in yeast, which supports replication of a TBSV replicon RNA (repRNA), reduced repRNA accumulation and the activity of the tombusvirus replicase by up to fivefold. Overexpression of wild-type Cdc34p, but not that of an E2-defective mutant of Cdc34p, increased repRNA accumulation, suggesting a significant role for the ubiquitin-conjugating enzyme function of Cdc34p in TBSV replication. Also, Cdc34p was able to ubiquitinate p33 in vitro. In addition, we have shown that p33 becomes ubiquitinated in vivo. We propose that ubiquitination of p33 likely alters its function or affects the recruitment of host factors during TBSV replication. [ABSTRACT FROM AUTHOR]

In plants, small RNA-guided processes referred to as RNA silencing control gene expression and serve as an efficient antiviral mechanism. Plant viruses are inducers and targets of RNA silencing as infection involves the production of functional virus-derived small interfering RNAs (siRNAs). Here we investigate the structural and genetic components influencing the formation of Tobacco rattle virus (TRV)-derived siRNAs. TRV siRNAs are mostly 21 nucleotides in length and derive from positive and negative viral RNA strands, although TRV siRNAs of positive polarity are significantly more abundant. This asymmetry appears not to correlate with the presence of highly structured regions of single-stranded viral RNA. The Dicer-like enzyme DCL4, DCL3, or DCL2 targets, alone or in combination, viral templates to promote synthesis of siRNAs of both polarities from all regions of the viral genome. The heterogeneous distribution profile of TRV siRNAs reveals differential contributions throughout the TRV genome to siRNA formation. Indirect evidence suggests that DCL2 is responsible for production of a subset of siRNAs derived from the 3' end region of TRV. TRV siRNA biogenesis and antiviral silencing are strongly dependent on the combined activity of the host-encoded RNA-dependent RNA polymerases RDR1, RDR2, and RDR6, thus providing evidence that perfectly complementary double-stranded RNA serves as a substrate for siRNA production. We conclude that the overall composition of viral siRNAs in TRV-infected plants reflects the combined action of several interconnected pathways involving different DCL and RDR activities. [ABSTRACT FROM AUTHOR]

Positive-strand RNA viruses, which can be devastating pathogens in humans, animals and plants, replicate their genomes on intracellular membranes. Here, we describe the three-dimensional ultrastructural organization of a tombusvirus replicase in yeast, a valuable model for exploring virus-host interactions. We visualized the intracellular distribution of a viral replicase protein using metal-tagging transmission electron microscopy, a highly sensitive nanotechnology whose full potential remains to be developed. These three-dimensional images show how viral replicase molecules are organized when they are incorporated into the active domains of the intracellular replication compartment. Our approach provides a means to study protein activation mechanisms in cells and to identify targets for new antiviral compounds. [ABSTRACT FROM AUTHOR]

Recent in vitro proteomics screens revealed that many host proteins could interact with the replication proteins of Tomato bushy stunt virus (TBSV), which is a small, plus-stranded RNA virus (Z. Li, D. Barajas, T. Panavas, D. A. Herbst, and P. D. Nagy, J. Virol. 82:6911-6926, 2008). To further our understanding of the roles of host factors in TBSV replication, we have tested the effect of Rsp5p, which is a member of the Nedd4 family of E3 ubiquitin ligases. The full-length Rsp5p, via its WW domain, is shown to interact with p33 and the central portion of p92pol replication proteins. We find that overexpression of Rsp5p inhibits TBSV replication in Saccharomyces cerevisiae yeast, while downregulation of Rsp5p leads to increased TBSV accumulation. The inhibition is caused by Rsp5p-guided degradation of p92pol, while the negative effect on the p33 level is less pronounced. Interestingly, recombinant Rsp5p also inhibits TBSV RNA replication in a cell-free replication assay, likely due to its ability to bind to p33 and p92pol. We show that the WW domain of Rsp5p, which is involved in protein interactions, is responsible for inhibition of TBSV replication, whereas the HECT domain, involved in protein ubiquitination, is not necessary for Rsp5p-mediated inhibition of viral replication. Overall, our data suggest that direct binding between Rsp5p and p92pol reduces the stability of p92pol, with consequent inhibition of TBSV replicase activity. [ABSTRACT FROM AUTHOR]

Soft tissue giant cell tumor is a rare tumor. It occurs mainly in adults, in the lower extremities, and it has not gender predominance. Clinically it has a multinodular aspect and the best therapeutic option is a conservative surgical resection. We describe the case of a 55-year-old man with a multilobullated neoformation that affected the first toe of left foot, with a hystopathological diagnosis of giant cell tumor of soft tissues. The therapy consisted on partial amputation of the affected toe, to remove completely the tumor. [ABSTRACT FROM AUTHOR]

Abstract: In comparison to single infections, co-infection of Nicotiana benthamiana with Potato virus X (PVX) and Potato virus Y (PVY) or Plum pox virus (PPV), resulted in increased systemic symptoms (synergism in pathology). Previous studies have shown that virus infections affected the accumulation of various microRNAs (miRNAs) and miRNA target genes. Our studies revealed that double infection by PVX and PVY or PPV that produced the most severe symptoms in N. benthamiana altered accumulation of miR156, 171, 398, and 168, and/or their target transcripts to a greater extent or in a different direction than single infections that produced milder symptoms. These findings indicate a differential effect on miRNA metabolism of the combined infection by two unrelated plant viruses, which may account in part for the severe symptoms caused by PVX/potyvirus-associated synergisms. [Copyright &y& Elsevier]

Abstract: To identify host proteins interacting with the membrane-bound replication proteins of tombusviruses, we performed membrane yeast two-hybrid (MYTH) screens based on yeast cDNA libraries. The screens led to the identification of 57 yeast proteins interacting with replication proteins of two tombusviruses. Results from a split ubiquitin assay with 12 full-length yeast proteins and the viral replication proteins suggested that the replication proteins of two tombusviruses interact with a similar set of host proteins. Follow-up experiments with the yeast Cpr1p cyclophilin, which has prolyl isomerase activity that catalyzes cis–trans isomerization of peptidyl–prolyl bonds, confirmed that Cpr1p interacted with the viral p33 replication protein in yeast and in vitro. Replication of Tomato bushy stunt virus replicon RNA increased in cpr1Δ yeast, while over-expression of Cpr1p decreased viral replication. We also show that the Ess1p parvulin prolyl isomerase partly complements Cpr1p function as an inhibitor of tombusvirus replication. [ABSTRACT FROM AUTHOR]

Abstract: Higher plants use RNA silencing as a defense mechanism against viral infections, but viruses may encode suppressor proteins that counteract these defenses. Several virus-encoded suppressors also exert an inhibitory effect on endogenous small RNA regulatory pathways. Here we characterized the Tobacco rattle virus-encoded 16-kDa (TRV-16K) protein as a suppressor that blocked local RNA silencing induced by single (s)- and double-stranded (ds) RNA, indicating that TRV-16K interfered with a step in the silencing pathway downstream of dsRNA formation. The suppressor activity of TRV-16K was severely compromised by moderate to high dosages of dsRNA inducer. When silencing was locally triggered by ssRNA or low levels of dsRNA, silencing suppression by TRV-16K was associated with reduced accumulation of silencing-related siRNAs. TRV-16K also prevented partially cell-to-cell movement and systemic propagation of silencing but not transitive amplification of RNA silencing. We showed that neither TRV nor TRV-16K caused a global deregulation of the microRNA-regulatory pathway in Arabidopsis, suggesting that interference with microRNA biology was not a prerequisite for TRV, and probably many other plant viruses, to develop systemic infections in plants. [Copyright &y& Elsevier]

The article presents the case of a 36-year-old man with cutaneous cartilaginous tumor on the dorsum of the distal phalanx of the third right toe. The tumor was diagnosed histopathologically with hematoxylin and eosin stain and was removed using a fish-mouth incision to prevent avulsion of the nail plate. According to the author, the tumors are composed of hyaline cartilage and the cells of cartilage have nuclei indicative of malignancy.

Plus-stranded RNA viruses induce membrane deformations in infected cells in order to build viral replication complexes (VRCs). Tomato bushy stunt virus (TBSV) co-opts cellular ESCRT (endosomal sorting complexes required for transport) proteins to induce the formation of vesicle (spherule)-like structures in the peroxisomal membrane with tight openings toward the cytosol. In this study, using a yeast (Saccharomyces cerevisiae) vps23Δ bro1Δ double-deletion mutant, we showed that the Vps23p ESCRT-I protein (Tsg101 in mammals) and Bro1p (ALIX) ESCRT-associated protein, both of which bind to the viral p33 replication protein, play partially complementary roles in TBSV replication in cells and in cell extracts. Dual expression of dominant- negative versions of Arabidopsis homologs of Vps23p and Bro1p inhibited tombusvirus replication to greater extent than individual expression in Nicotiana benthamiana leaves. We also demonstrated the critical role of Snf7p (CHMP4), Vps20p, and Vps24p ESCRT-III proteins in tombusvirus replication in yeast and in vitro. Electron microscopic imaging of vps23Δ yeast revealed the lack of tombusvirus-induced spherule-like structures, while crescent-like structures are formed in ESCRT-III deletion yeasts replicating TBSV RNA. In addition, we also showed that the length of the viral RNA affects the sizes of spherules formed in N. benthamiana cells. The 4.8-kb genomic RNA is needed for the formation of spherules 66 nm in diameter, while spherules formed during the replication of the ~600-nucleotide (nt)-long defective interfering RNA in the presence of p33 and p92 replication proteins are 42 nm. We propose that the viral RNA serves as a "measuring string" during VRC assembly and spherule formation. [ABSTRACT FROM AUTHOR]

RNA viruses exploit host cells by co-opting host factors and lipids and escaping host antiviral responses. Previous genome-wide screens with Tomato bushy stunt virus (TBSV) in the model host yeast have identified 18 cellular genes that are part of the actin network. In this paper, we show that the p33 viral replication factor interacts with the cellular cofilin (Cof1p), which is an actin depolymerization factor. Using temperature-sensitive (ts) Cof1p or actin (Act1p) mutants at a semi-permissive temperature, we find an increased level of TBSV RNA accumulation in yeast cells and elevated in vitro activity of the tombusvirus replicase. We show that the large p33 containing replication organelle-like structures are located in the close vicinity of actin patches in yeast cells or around actin cable hubs in infected plant cells. Therefore, the actin filaments could be involved in VRC assembly and the formation of large viral replication compartments containing many individual VRCs. Moreover, we show that the actin network affects the recruitment of viral and cellular components, including oxysterol binding proteins and VAP proteins to form membrane contact sites for efficient transfer of sterols to the sites of replication. Altogether, the emerging picture is that TBSV, via direct interaction between the p33 replication protein and Cof1p, controls cofilin activities to obstruct the dynamic actin network that leads to efficient subversion of cellular factors for pro-viral functions. In summary, the discovery that TBSV interacts with cellular cofilin and blocks the severing of existing filaments and the formation of new actin filaments in infected cells opens a new window to unravel the way by which viruses could subvert/co-opt cellular proteins and lipids. By regulating the functions of cofilin and the actin network, which are central nodes in cellular pathways, viruses could gain supremacy in subversion of cellular factors for pro-viral functions. [ABSTRACT FROM AUTHOR]

In recent years higher education has experienced rapid expansion due to, among other things, the imperative of preparing the tables of technical, professional and research that meet the requirements of economic development, political and social life. Based on this growth and because of the curricular issues facing higher education institutions, has created a need to rationalize and systematize the curriculum development efforts taking place in them. The concept of social need is part of the deficiencies that are identified with an ideal situation, beneficial to the individual and the community, and whose satisfaction requires the response of other members of society or its institutions. The aim of this study was to identify the demand for degree programs in humanities offered by the Faculty of Arts, in various regions of the state of Puebla, specifically in the regions of Chignahuapan-Zacatlán, Teziutlán and Tehuacan, in order that can be incorporated into the model of regionalization of the Autonomous University of Puebla. The method used for this study was descriptive and analytical to carry out a survey applied to 4075 students last semester of high school in the area of social sciences and humanities. Through this work we present the results obtained in each of the identified regions and a general comparison that shows the demand for each of the degrees offered at the Faculty of Arts. [ABSTRACT FROM AUTHOR]

Background: Nevus sebaceous of Jadassohn is a congenital hamartomatous lesion, which involves sebaceous gland, apocrine, and trichilemmal proliferative changes. It presents three clinical stages; the last one is characterized by epithelial tumors arising. Objective: To determine the frequency and associated tumors type, as well as the clinic and epidemiologic characteristics related with them. Material and method: A retrospective analysis at the Instituto Dermatológico de Jalisco Dr. José Barba Rubio during a five-year period was made. All histopathology reports of nevus sebaceous of Jadassohn were included and three different pathologists in a blind fashion reviewed the slides of tumors arising in nevus sebaceous. Results: We included 260 cases with diagnostic of nevus sebaceous of Jadassohn, mean age 19.7 years, female sex predominance (55%), the most frequent localization was scalp (61.5%). Eleven per cent of the 260 cases were in tumor stage, with predominance in 31 to 40 years old (27.5%). Benign tumors were the most frequent (97%), trichoblastoma predominated (50%); only one case of basal cell carcinoma was found. More than one tumor was associated to nevus sebaceous of Jadassohn in 13.7% of cases. Conclusions: Arising malignant tumors in nevus sebaceous of Jadassohn are uncommon, moreover in pediatric age. Prospective studies are necessary in order to determine the real association with nevus sebaceous of Jadassohn tumors. [ABSTRACT FROM AUTHOR]

The effects on symptom expression of single amino acid mutations in the central region of the Plum pox virus (PPV) helper component-proteinase (HC-Pro) gene were analyzed in Nicotiana benthamiana using Potato virus X (PVX) recombinant viruses. PVX recombinant virus expressing the wild-type variant of PPV HC-Pro induced the expected enhancement of PVX pathogenicity, manifested as necrosis and plant death. Recombinant virus expressing a variant of PPV HC-Pro containing a single point mutation (HCL 134H) was unable to induce this synergistic phenotype. The RNA silencing suppressor activity of PPV HC-Pro was demonstrated in a transient silencing suppression assay. In contrast, the HCL134H mutant showed no such activity. These results indicate that a unique point mutation in PPV HC-Pro impaired its ability to suppress RNA silencing and abolished its capacity to induce synergism, and clearly shows for the first time the link between these two functions in potyvirus HC-Pro. Additionally. we compared the effects on virus accumulation in N. benthamiana plants infected with either the PVX recombinant constructs or with native viruses in double infection experiments. PVX (+) and (-) strand genomic RNA accumulated at similar levels in plants infected with PVX recombinants, leading to an increase in PVX pathology, compared with plants infected with PVX alone. This finding confirms that the enhancement of pathogenicity associated with synergistic interaction is not a consequence of more efficient PVX replication due to RNA silencing suppression by PPV HC-Pro. Additional keywords: posttranscriptional gene silencing. [ABSTRACT FROM AUTHOR]