Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process

Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin

Comparison of shear bond strength of veneering ceramic to zirconia after surface treatment with air abrasion and laser treatment: An In vitro study

INTRODUCTION: The use of All Ceramic restorations as an alternative to metal ceramic restorations has substantially increased over the last few decades. Zirconia serves as a core ceramic in fixed dental restoration as it has excellent biocompatibility, wear resistance, flexural strength, and fracture toughness. However, delamination and chipping of veneer are the two common failure modes of zirconia restorations. The success of zirconia based all ceramic restorations dependent on the stable bonding between zirconia core and veneering ceramic. Enhancement of the adhesion between the zirconia substrate and the veneering ceramic is essential for the clinical success of zirconia restorations. The present study investigated the effect of various surface treatments on the interfacial bonding between zirconia and ceramic. Here, the purpose of the present study is to evaluate and compare the shear bond strength between zirconia and veneering ceramic after surface treatment with sandblasting and laser. AIMS AND OBJECTIVES: 1. Determination of shear bond strength between zirconia and veneering ceramic after sandblasting with 110-micron Alumina (Al2O3) particles. 2. Determination of shear bond strength between zirconia and veneering ceramic after Nd YAG laser treatment. 3. Comparison of shear bond strength of veneering ceramic to zirconia: i. without surface treatment, ii. with sandblasting and iii. with laser treatment. METHODOLOGY: In the present study, specific dimension of zirconia block was designed using Design software. The file created was saved in STL format. As per the data available 3Y-TZP block was machined to 7 mm thickness, 7 mm breadth and 15 mm length rectangular samples using milling machine. These samples were sintered using sintering furnace. These samples were cleaned ultrasonically using Ultrasonic cleaner and further cleaned with demineralized water, followed by drying in hot air. Among thirty zirconia blocks ten zirconia were sandblasted, ten were laser treated and remaining were taken as control. All specimens were veneered with ceramic and subjected to shear stress in Instron 3345 Universal testing machine. The data were analysed with ANOVA followed by Dunnett ‘t’ test with a significance value less than 0.05 (p<0.05). Scanning Electron Microscopy of the sandblasted and laser treated samples were done at 500X, 1000X, 2000X to evaluate the surface roughness of the zirconia surface after surface treatments. RESULTS: In the present study the mean value of shear bond strength was 28.30±2.92 MPa for control group, 33.92±2.67 MPa for sandblasted and 41.67±5.16 MPa for laser treated group. These results were statistically analyzed using ANOVA (Post hoc) followed by Dunnett ‘t’ test applied and find that these results were statistically significant (p < 0.05) between the groups. SUMMARY AND CONCLUSION: Although it was proved that surface treatment improved the bond strength of both sandblasted and laser treated zirconia; the increase in bond strength of laser treated specimen was higher than that of sandblasted one. However further clinical research is suggested in order to prove it as a reliable and successful modality

Current Standards in the Management of Cerebral Metastases

The last 30 years have seen major changes in attitude toward patients with cerebral metastases. This paper aims to outline the major landmarks in this transition and the therapeutic strategies currently used. The controversies surrounding control of brain disease are discussed, and two emerging management trends are reviewed: tumor bed radiosurgery and salvage radiation

Pathogenic variation of colletotrichum lindemuthianum causing anthracnose of beans (phaseolus vulgaris) in Uganda

This is an open access article accessible from the publisher's site at https://www.escijournals.net/index.php/phytopath/article/view/1980/984Colletotrichum lindemuthianum is a highly variable pathogen of common beans that easily overcomes resistance in cultivars bred with single-gene resistance. To determine pathogenic variability of the pathogen in Uganda, samples of common bean tissues with anthracnose symptoms were collected in eight districts of Uganda, namely Kabarole, Sironko, Mbale, Oyam, Lira, Kapchorwa, Maracha and Kisoro. 51 isolates sporulated successfully on Potato Dextrose Agar and Mathur’s media and were used to inoculate 12 differential cultivars under controlled conditions. Five plants per cultivar were inoculated with each isolate and then evaluated for their reaction using the 1 – 9 severity scale. Races were classified using the binary nomenclature system proposed by Pastor Corrales (1991). Variation due to cultivar and isolate effects was significant (P≤0.001) for severity. The 51 isolates from eight districts grouped into 27 different races. Sironko district had the highest number of races followed by Mbale and Kabarole. Races 2047 and 4095 were the most frequently found, each with 10 isolates grouped under them. Race 4095 was the most virulent since it caused a susceptible (S) reaction on all 12 differential cultivars and the susceptible check. This was followed by races 2479, 2047 and 2045 respectively. Two races, 4094 and 2479, caused a susceptible reaction on the differential cultivar G2333, which nevertheless, showed the most broad spectrum resistance followed by cultivars Cornell 49-242, TU, and AB136 respectively. These cultivars are recommended for the use in breeding programs aiming at breeding for broad spectrum resistance to bean anthracnose in Uganda.Uganda National Council of Science and Technology (UNCST) funded the study through the Millennium Science Initiative (MSI) project. Additional funding was provided by CIAT-Uganda and the ATAAS project under the National Agricultural Research Organization (NARO)

Laminoplasty Versus Laminectomy With Fusion for Treating Multilevel Degenerative Cervical Myelopathy

BACKGROUND: Laminectomy with fusion (LF) and laminoplasty (LP) are common posterior decompression procedures used to treat multilevel degenerative cervical myelopathy (DCM). There is debate on their relative efficacy and safety for treatment of DCM. The goal of this study is to examine outcomes and costs of LF and LP procedures for DCM. METHODS: This is a retrospective review of adult patients ( RESULTS: LP cohort (n=76) and LF cohort (n=59) reported no difference in neck pain at baseline, 1, 6, 12, and 24 months postoperatively (p\u3e.05). Patients were successfully weaned off opioids at similar rates (LF: 88%, LP: 86%). Fixed and variable costs respectively with LF cases hospital were higher, 15.7% and 25.7% compared to LP cases (p=.03 and p CONCLUSIONS: When treating multilevel DCM, LP has similar rates of new or increasing axial neck pain compared to LF. LF was associated with greater hospital costs, length of stay, and complications compared to LP. LP may in fact be a less morbid and more cost-effective alternative to LF for patients without cervical deformity

SUSCEPTIBILITY TO BRUCHIDS AMONG COMMON BEANS IN UGANDA

The bean bruchids, Acanthoscelides obtectus Say and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae), are cosmopolitan pests of stored dry common beans ( Phaseolus vulgaris L. ), causing damage through reduction of grain quality and seed germination. Biological resistance to these bruchids was definitively established in non-cultivated bean accessions, and has been introgressed into a range of drybean market classes. However, existing resistance to bruchids in Uganda\u2019s common bean germplasm has not been systematically studied. In this study, 45 bean genotypes from the National Bean-Breeding Programme (25 genotypes) and agroecologically diverse bean growing areas in Uganda (20 genotypes), were evaluated for postharvest bruchid resistance. None of the evaluated bean genotypes expressed resistance to either bruchid species, with all the 45 bean genotypes supporting bruchid development, reproduction and feeding. All genotypes were severely damaged by bruchids feeding, resulting in significant (P&lt;0.05) reduction of seed germination. Reduction in seed germination was related to the number of emergence holes and seed size; small bean seeds damaged by up to 2 bruchid emergence holes had a 7.1% reduction in germination, while large bean seeds with a similar number of emergence holes showed a 25% reduction in germination. Whereas this study further confirms bruchids as important storage pests of beans causing direct loss through consumption of the seed and indirect loss through viability deterioration, the resistance to bruchids in the evaluated range of Uganda\u2019s dry bean germplasm is inadequate for direct exploitation in a breeding programme.Les bruches du haricot, Acanthoscelides obtectus Say et Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae), sont des ravageurs cosmopolites des haricots secs stock\ue9s ( Phaseolus vulgaris L. ), provoquant des dommages en r\ue9duisant la qualit\ue9 des grains et le pouvoir germinatif des semences. La r\ue9sistance biologique \ue0 ces bruches a \ue9t\ue9 d\ue9finitivement \ue9tablie dans des lign\ue9es non cultiv\ue9es de haricots et a \ue9t\ue9 introgress\ue9e dans une gamme vari\ue9e de haricots commercialis\ue9s. Cependant, la r\ue9sistance actuelle aux bruches dans le mat\ue9riel g\ue9n\ue9tique des haricots commun\ue9ment r\ue9pandus en Ouganda n\u2019a pas \ue9t\ue9 syst\ue9matiquement \ue9tudi\ue9e. Dans la pr\ue9sente \ue9tude, 45 g\ue9notypes de haricots provenant du Programme national d\u2019am\ue9lioration du haricot (25 g\ue9notypes) et de diverses zones agro-\ue9cologiques de culture de haricots en Ouganda (20 g\ue9notypes), ont \ue9t\ue9 \ue9valu\ue9s pour leur r\ue9sistance post-r\ue9colte aux bruches. Aucun des g\ue9notypes \ue9valu\ue9s n\u2019a exprim\ue9 de la r\ue9sistance aux deux esp\ue8ces de bruches, et tous les 45 g\ue9notypes ont favoris\ue9 le d\ue9veloppement des bruches, leur reproduction et leur alimentation. Tous les g\ue9notypes ont \ue9t\ue9 gravement endommag\ue9s du fait de l\u2019alimentation des bruches, ce qui a entra\ueen\ue9 une r\ue9duction significative (P &lt;0,05) de la germination des graines. La r\ue9duction du pouvoir germinatif \ue9tait li\ue9e au nombre de trous caus\ue9s sur les graines et \ue0 la taille des graines; les petites graines de haricot endommag\ue9es avec jusqu\u2019\ue0 2 trous ont montr\ue9 une r\ue9duction de 7,1% de leur pouvoir germinatif, tandis que les grandes graines de haricots endommag\ue9es avec le m\ueame nombre de trous ont connu une r\ue9duction de 25% de pouvoir germinatif. Bien que cette \ue9tude confirme davantage que les bruches sont d\u2019importants ravageurs en phase de stockage des haricots causant des pertes \ue0 la fois directe par la consommation de la graine et indirecte par la d\ue9t\ue9rioration de la viabilit\ue9 des semences, la r\ue9sistance aux bruches dans la gamme \ue9tudi\ue9e du mat\ue9riel g\ue9n\ue9tique de haricots secs de l\u2019Ouganda est insuffisante pour une exploitation directe dans un programme d\u2019am\ue9lioration vari\ue9tale

Regulation of RasGRP1 Function in T Cell Development and Activation by Its Unique Tail Domain

The Ras-guanyl nucleotide exchange factor RasGRP1 plays a critical role in T cell receptor-mediated Erk activation. Previous studies have emphasized the importance of RasGRP1 in the positive selection of thymocytes, activation of T cells, and control of autoimmunity. RasGRP1 consists of a number of well-characterized domains, which it shares with its other family members; however, RasGRP1 also contains an ∼200 residue-long tail domain, the function of which is unknown. To elucidate the physiological role of this domain, we generated knock-in mice expressing RasGRP1 without the tail domain. Further analysis of these knock-in mice showed that thymocytes lacking the tail domain of RasGRP1 underwent aberrant thymic selection and, following TCR stimulation, were unable to activate Erk. Furthermore, the deletion of the tail domain led to enhanced CD4+ T cell expansion in aged mice, as well as the production of autoantibodies. Mechanistically, the tail-deleted form of RasGRP1 was not able to traffic to the cell membrane following stimulation, indicating a potential reason for its inability to activate Erk. While the DAG-binding C1 domain of RasGRP1 has long been recognized as an important factor mediating Erk activation, we have revealed the physiological relevance of the tail domain in RasGRP1 function and control of Erk signaling

Adaptor SKAP-55 Binds p21ras Activating Exchange Factor RasGRP1 and Negatively Regulates the p21ras-ERK Pathway in T-Cells

While the adaptor SKAP-55 mediates LFA-1 adhesion on T-cells, it is not known whether the adaptor regulates other aspects of signaling. SKAP-55 could potentially act as a node to coordinate the modulation of adhesion with downstream signaling. In this regard, the GTPase p21ras and the extracellular signal-regulated kinase (ERK) pathway play central roles in T-cell function. In this study, we report that SKAP-55 has opposing effects on adhesion and the activation of the p21ras -ERK pathway in T-cells. SKAP-55 deficient primary T-cells showed a defect in LFA-1 adhesion concurrent with the hyper-activation of the ERK pathway relative to wild-type cells. RNAi knock down (KD) of SKAP-55 in T-cell lines also showed an increase in p21ras activation, while over-expression of SKAP-55 inhibited activation of ERK and its transcriptional target ELK. Three observations implicated the p21ras activating exchange factor RasGRP1 in the process. Firstly, SKAP-55 bound to RasGRP1 via its C-terminus, while secondly, the loss of binding abrogated SKAP-55 inhibition of ERK and ELK activation. Thirdly, SKAP-55−/− primary T-cells showed an increased presence of RasGRP1 in the trans-Golgi network (TGN) following TCR activation, the site where p21ras becomes activated. Our findings indicate that SKAP-55 has a dual role in regulating p21ras-ERK pathway via RasGRP1, as a possible mechanism to restrict activation during T-cell adhesion

Evolutionary expansion of the Ras switch regulatory module in eukaryotes

Ras proteins control many aspects of eukaryotic cell homeostasis by switching between active (GTP-bound) and inactive (GDP-bound) conformations, a reaction catalyzed by GTPase exchange factors (GEF) and GTPase activating proteins (GAP) regulators, respectively. Here, we show that the complexity, measured as number of genes, of the canonical Ras switch genetic system (including Ras, RasGEF, RasGAP and RapGAP families) from 24 eukaryotic organisms is correlated with their genome size and is inversely correlated to their evolutionary distances from humans. Moreover, different gene subfamilies within the Ras switch have contributed unevenly to the module’s expansion and speciation processes during eukaryote evolution. The Ras system remarkably reduced its genetic expansion after the split of the Euteleostomi clade and presently looks practically crystallized in mammals. Supporting evidence points to gene duplication as the predominant mechanism generating functional diversity in the Ras system, stressing the leading role of gene duplication in the Ras family expansion. Domain fusion and alternative splicing are significant sources of functional diversity in the GAP and GEF families but their contribution is limited in the Ras family. An evolutionary model of the Ras system expansion is proposed suggesting an inherent ‘decision making’ topology with the GEF input signal integrated by a homologous molecular mechanism and bifurcation in GAP signaling propagation

Phospholipase Cγ1 is essential for T cell development, activation, and tolerance

Phospholipase Cγ1 (PLCγ1) is an important signaling effector of T cell receptor (TCR). To investigate the role of PLCγ1 in T cell biology, we generated and examined mice with T cell–specific deletion of PLCγ1. We demonstrate that PLCγ1 deficiency affects positive and negative selection, significantly reduces single-positive thymocytes and peripheral T cells, and impairs TCR-induced proliferation and cytokine production, and the activation of ERK, JNK, AP-1, NFAT, and NF-κB. Importantly, PLCγ1 deficiency impairs the development and function of FoxP3+ regulatory T cells, causing inflammatory/autoimmune symptoms. Therefore, PLCγ1 is essential for T cell development, activation, and tolerance