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1.
Exp Parasitol ; 208: 107801, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31730781

ABSTRACT

Taenia solium is a parasite whose larvae (cysticerci) can locate in the central nervous system of humans and cause neurocysticercosis (NC). The introduction of cysticidal drugs such as albendazole (ABZ) for the treatment of NC has significantly improved its prognosis. However, treatment is not always effective, and the high levels of corticosteroids used to prevent inflammatory complications in this disease could be, partly, the cause of this observation. In this context, this study investigated, using the experimental mouse model of intraperitoneal infection with Taenia crassiceps, the influence of corticosteroid administration on the therapeutic efficacy of ABZ. We evaluated and compared the effects of ABZ, dexamethasone (DXM) and their combination (ABZ + DXM) on cyst viability, both in vitro and in vivo. Serum levels of IL-4, IFN-gamma, IL-6 and IL-10 were evaluated in the in vivo study. Results showed that the treatment with ABZ, in vitro and in vivo, was associated with a high number of parasites deaths. Concomitant treatment with DXM did not alter ABZ in vitro cysticidal activity but reduced its effectiveness significantly in the in vivo experimental model. Cytokine serum levels did not change significantly in treated mice compared to the controls. The results of this study are relevant as they indicate a negative effect of corticosteroids on the efficacy of cysticidal therapy. In human neurocysticercosis, control of inflammation is of great importance to most patients in order to avoid complications. Corticosteroids are generally used for this purpose and the results of this study demonstrate the need to find other therapeutic strategies. Further studies are needed to better understand the mechanisms involved.


Subject(s)
Albendazole/pharmacology , Anthelmintics/pharmacology , Anti-Inflammatory Agents/pharmacology , Cysticercosis/drug therapy , Dexamethasone/pharmacology , Taenia/drug effects , Albendazole/therapeutic use , Animals , Anthelmintics/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Dexamethasone/therapeutic use , Drug Interactions , Enzyme-Linked Immunosorbent Assay , Female , Interferon-gamma/blood , Interleukin-10/blood , Interleukin-4/blood , Interleukin-6/blood , Mice , Mice, Inbred BALB C
2.
Parasitol Res ; 119(8): 2521-2529, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32591864

ABSTRACT

The enzyme-linked immunoelectrotransfer blot (EITB) assay to detect antibodies in serum is a complementary tool for the diagnosis of neurocysticercosis (NCC). Presence of at least one glycoprotein band corresponding to a Taenia solium (T. solium) antigen indicates a positive result; however, EITB assays have multiple glycoprotein bands, and previous work has suggested that band patterns may have additional diagnostic value. We included 58 participants with a definitive diagnosis of NCC who received care at the Instituto Nacional de Neurología y Neurocirugía in Mexico City. Three different EITB tests were applied to participants' serum samples (LDBio, France; US Centers for Disease Control and Prevention [CDC]; and Instituto de Diagnóstico y Referencia Epidemiológicos [InDRE]). There was substantial variability in specific glycoprotein band patterns among the three assays. However, in age- and sex-adjusted logistic regression models, the number of glycoprotein bands was positively associated with the presence of vesicular extraparenchymal cysts (InDRE adjusted odds ratio [aOR] 1.60 p < 0.001; CDC aOR 6.31 p < 0.001; LDBio aOR 2.45 p < 0.001) and negatively associated with the presence of calcified parenchymal cysts (InDRE aOR 0.63 p < 0.001; CDC aOR 0.25 p < 0.001; LDBio aOR 0.44 p < 0.001). In a sensitivity analysis also adjusting for cyst count, results were similar. In all three EITB serum antibody tests, the number of glycoprotein bands consistently predicted cyst stage and location, although magnitude of effect differed.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Glycoproteins/analysis , Helminth Proteins/analysis , Neurocysticercosis/diagnosis , Taenia solium/isolation & purification , Animals , Antibodies, Helminth/analysis , Antigens, Helminth/analysis , Antigens, Helminth/immunology , Female , France , Glycoproteins/immunology , Helminth Proteins/immunology , Humans , Male , Mexico , Neurocysticercosis/parasitology , Odds Ratio , Sensitivity and Specificity , Taenia solium/growth & development , Taenia solium/immunology
3.
Parasitol Res ; 118(10): 2891-2899, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31418112

ABSTRACT

Immunodiagnosis has a supportive role in the diagnosis of neurocysticercosis (NCC). The aim of this study was to compare the validity of seven immunodiagnostic tests among serum samples from 58 patients with NCC, 26 patients with neurological diseases other than NCC, and 15 healthy controls. One test for viable parasite detection (HP10 antigen assay) and six for antibody detection were evaluated. For the entire sample, sensitivities ranged from 55.2% (NOVALISA) to 81.0% (enzyme-linked immunosorbent assay [ELISA] Taenia solium antibody), with the sensitivity of the latter test significantly higher than that of the in-house ELISA Taenia crassiceps, NOVALISA, enzyme-linked immunoelectrotransfer blot (EITB) CDC, and HP10. Overall, specificities were high, ranging from 85.4% (ELISA Ts) to 97.1% (NOVALISA), with no statistically significant differences. Detection of HP10 antigen was significantly associated with the presence of vesicular parasites. The simple and low-cost ELISA Taenia solium antibody Ab instead of EITB is recommended to support NCC diagnosis in both rural and hospital settings in Mexico.


Subject(s)
Antibodies, Helminth/blood , Antigens, Helminth/immunology , Diagnostic Tests, Routine/methods , Neurocysticercosis/diagnosis , Taenia solium/immunology , Adult , Animals , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Immunologic Tests/methods , Male , Mexico , Neurocysticercosis/immunology , Rural Population , Sensitivity and Specificity
4.
Exp Parasitol ; 2016 Oct 27.
Article in English | MEDLINE | ID: mdl-27983954

ABSTRACT

A lateral flow assay (LFA) for the diagnosis and monitoring of extraparenchymal neurocysticercosis, has been developed. The assay is based on the use of the monoclonal antibody HP10, and when applied to cerebrospinal fluid, correctly identified 34 cases of active extraparenchymal neurocysticercosis, but was negative with 26 samples from treated and cured neurocysticercosis patients and with 20 samples from unrelated neurological diseases. There was complete agreement between the HP10 Ag-ELISA results and the HP10-LFA. The HP10-LFA thus has utility for diagnosis and treatment of extraparenchymal neurocysticercosis, frequently a more dangerous form of the infection.

5.
Biochim Biophys Acta ; 1844(4): 837-49, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24590112

ABSTRACT

MARCKS (Myristoylated Alanine-Rich C Kinase substrate) is a natively unfolded protein that interacts with actin, Ca(2+)-Calmodulin, and some plasma membrane lipids. Such interactions occur at a highly conserved region that is specifically phosphorylated by PKC: the Effector Domain. There are two other conserved domains, MH1 (including a myristoylation site) and MH2, also located in the amino terminal region and whose structure and putative protein binding capabilities are currently unknown. MH2 sequence contains a serine that we described as being phosphorylated only in differentiating neurons (S25 in chick). Here, Circular Dichroism (CD) and Nuclear Magnetic Resonance (NMR) spectroscopy were used to characterize the phosphorylated and unphosphorylated forms of a peptide with the MARCKS sequence surrounding S25. The peptide phosphorylated at this residue is recognized by monoclonal antibody 3C3 (mAb 3C3). CD and NMR data indicated that S25 phosphorylation does not cause extensive modifications in the peptide structure. However, the sharper lines, the absence of multiple spin systems and relaxation dispersion data observed for the phosphorylated peptide suggested a more ordered structure. Surface Plasmon Resonance was employed to compare the binding properties of mAb 3C3 to MARCKS protein and peptide. SPR showed that mAb 3C3 binds to the whole protein and the peptide with a similar affinity, albeit different kinetics. The slightly ordered structure of the phosphorylated peptide might be at the origin of its ability to interact with mAb 3C3 antibody, but this binding did not noticeably modify the peptide structure.


Subject(s)
Intracellular Signaling Peptides and Proteins/chemistry , Membrane Proteins/chemistry , Peptides/chemistry , Phosphoproteins/chemistry , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , Brain Chemistry , Chick Embryo , Circular Dichroism , Intracellular Signaling Peptides and Proteins/immunology , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/immunology , Membrane Proteins/metabolism , Mice , Molecular Sequence Data , Myristoylated Alanine-Rich C Kinase Substrate , Peptides/chemical synthesis , Peptides/metabolism , Phosphoproteins/isolation & purification , Phosphoproteins/metabolism , Phosphorylation , Protein Interaction Domains and Motifs , Protein Kinase C/chemistry , Protein Kinase C/metabolism , Protein Structure, Secondary , Surface Plasmon Resonance
6.
Chromosome Res ; 21(8): 789-803, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24323064

ABSTRACT

DNA damage may lead to cell transformation, senescence, or death. Histone H2AX phosphorylation, immunodetected as γH2AX foci, is an early response to DNA damage persisting even after DNA repair. In cycling mammalian cells with canonical nuclear architecture, i.e., central euchromatin and peripheral heterochromatin, γH2AX foci map preferentially to euchromatin. Mice retina rods are G0 cells displaying an inverted nuclear architecture 28 days after birth (P28). Rod nuclei exhibit one or two central constitutive heterochromatin chromocenters encircled by facultative heterochromatin. Euchromatin resides at the nuclear periphery, extending to the equator in cells with two chromocenters. To assess the impact of chromatin relocation in the localization of DNA damage, γH2AX and TUNEL foci induced ex vivo by radiomimetic bleomycin were mapped in H3K4me3 immunolabeled P28 rod nuclei. A preferential localization of γH2AX foci in euchromatin was detected together with foci clustering. Besides, a decay of H3K4me3 signal at γH2AX foci sites was observed. TUNEL and γH2AX foci exhibited similar localization patterns in BLM-treated rod cells thus excluding curtailed access of anti-γH2AX antibodies to heterochromatin. Lack of γH2AX foci in rod chromocenters appears to be unrelated to the occurrence of mid-range foci movements. Foci clusters may arise through DNA double-strand break proximity, local non-directional chromatin movements or chromatin relaxation. H3K4me3 signal reduction at γH2AX foci could stem from local chromatin decondensation or downregulation of histone H4 methylation. The observed topology of DNA damage in retina-differentiated rods indicates that euchromatin is damage-prone, regardless of the canonical or inverted nuclear architecture of mammalian cells.


Subject(s)
DNA Breaks, Double-Stranded/drug effects , Euchromatin/metabolism , Heterochromatin/drug effects , Histones/metabolism , Retinal Rod Photoreceptor Cells/drug effects , Animals , Bleomycin/adverse effects , Cysteine Endopeptidases/metabolism , DNA Repair/drug effects , Euchromatin/genetics , Heterochromatin/metabolism , Histones/genetics , Image Processing, Computer-Assisted , In Situ Nick-End Labeling , Leucine/analogs & derivatives , Leucine/pharmacology , Mice , Multigene Family , Phosphorylation , Retinal Rod Photoreceptor Cells/metabolism
7.
J Insect Sci ; 13: 18, 2013.
Article in English | MEDLINE | ID: mdl-23885970

ABSTRACT

A mycosed planthopper, Oliarus dimidiatus Berg (Hemiptera: Cixiidae), and two psocids, Heterocaecilius sp. (Psocodea: Pseudocaeciliidae) and Ectopsocus sp. (Ectopsocidae), were collected from Los Hornos and La Plata, Buenos Aires, Argentina between February and September 2007. Observations of mycelia growing on the host revealed that the putative fungal parasite had synnemata supporting monophialidic conidiogenous cells. Likewise, in vitro fungal cultures presented characteristics typical of the fungus Hirsutella citriformis Speare (Ascomycota: Hypocreales: Clavicipitaceae). The identity of the isolated fungi characterized based on morphological aspects was complemented by means of the internal transcribed spacer sequences. The sequences of both isolates were highly homologous to those of Cordyceps sp. (Fries) Link and Ophiocordyceps sinensis (Berkely) G.H. Sung, J.M. Sung, Hywel-Jones, and Spatafora (Ophiocordycipitaceae). We additionally confirmed that both isolates had the ability to infect and kill adults of Delphacodes kuscheli Fennah (Hemiptera: Delphacidae) after 10 days. Therefore, based on the morphology of the isolated fungi, their ribosomal internal transcribed spacer sequence, and their ability to parasite insects, we conclude that the fungi isolated belong to the genus Hirsutella and might have biotechnological potential.


Subject(s)
Hemiptera/microbiology , Host-Pathogen Interactions , Hypocreales/physiology , Animals , Phylogeny , Sequence Analysis, DNA
8.
Pathogens ; 12(9)2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37764924

ABSTRACT

Extraparenchymal neurocysticercosis (EP-NC) is a chronic, potentially life-threatening disease that responds poorly to initial anthelmintic drug therapy. A depressed specific reactivity of peripheral lymphocytes and an increased level of specific Tregs accompanies EP-NC. The immune checkpoint pathway PD-1 and its ligand PD-L1 downregulates effector T cells, causing specific immune suppression in chronic diseases. This study explored whether their soluble forms, sPD-1/sPD-L1, are present in plasma among patients with EP-NC and if their levels could be associated with treatment response. A total of 21 patients with vesicular EP-NC and 22 healthy controls were included. Patients received standard treatment and were followed for six months to assess treatment response by assessing changes in cyst volume determined with 3D MRI. The presence of both sPD-1 and sPD-L1 was more frequently detected among patients with EP-NC than in healthy controls and had higher concentrations. Among patients, higher pre-treatment levels of both markers were associated with a poor treatment response, and the sensitivity and specificity of the sPD-1/sPD-L1 ratio for predicting any response to treatment were high. Our results are consistent with the presence of lymphocyte exhaustion and open new research perspectives to improve the prognosis of patients with this severe disease.

9.
Pathog Glob Health ; 117(1): 5-13, 2023 02.
Article in English | MEDLINE | ID: mdl-35657099

ABSTRACT

In Guatemala, neurocysticercosis (NCC) was first recognized in 1940; since then, cases of NCC have been reported in all Guatemalan departments. However, epidemiological studies on Taenia solium infections are scarce and most information remains unpublished. This study aims to provide evidence of T. solium infections as a public health problem in Guatemala. All information available, either published or unpublished, on T. solium infections in the country was compiled. Official data from the Ministry of Health for the period 2003-2019 were reviewed and analyzed, and all cases of T. solium infections were classified and counted. In total, 5246 cases of taeniasis and 454 cases of human cysticercosis were recorded. On the other hand, 44 studies were identified, mostly from local journals, which included 1951 cases of taeniasis, 2873 cases of human cysticercosis of which 543 were classified with complete diagnosis, and 2590 cases of porcine cysticercosis. Cases were classified by geographic region, patient sex, and Taenia species in taeniasis cases when information was available, and the departments with the highest number of taeniasis and cysticercosis cases were identified. Meanwhile, in Zacapa, a northeastern department of Guatemala with one the highest number of taeniasis cases, a young man diagnosed with a severe form of NCC and two cases of porcine cysticercosis (both confirmed by necropsy) were identified. Taken together, the data herein reported indicate that T. solium infections are a major health problem in Guatemala that needs to be addressed.


Subject(s)
Cysticercosis , Neurocysticercosis , Taenia solium , Taeniasis , Male , Humans , Animals , Swine , Public Health , Guatemala/epidemiology , Cysticercosis/epidemiology , Taeniasis/epidemiology , Taeniasis/diagnosis , Neurocysticercosis/epidemiology
10.
PLoS Negl Trop Dis ; 17(6): e0011386, 2023 06.
Article in English | MEDLINE | ID: mdl-37262055

ABSTRACT

BACKGROUND: The morbidity and mortality of extraparenchymal neurocysticercosis (EP-NC) remain high and effectiveness of current medical treatment is suboptimal. Various factors have been implicated in the severity of EP-NC and in the poor response to treatment, but the possible role of host immune and endocrine systems has not yet been examined thoroughly. METHODOLOGY/PRINCIPAL FINDINGS: 42 participants with EP-NC before receiving standard treatment and 25 healthy controls were included in the study. Treatment response was assessed by comparing pre/post treatment parasite volumes from 3D MRI. Prior to treatment among participants with EP-NC, specific stimulation induced an increased specific proliferative response accompanied by a significant increase in IL-4, NK, NKT, Bregs and Tregs cells, whereas in healthy controls, specific stimulation induced a significant increase in IL-1ß, IL-5, CCL5, IL-6, TNF-α, NK and Bregs cells. Significant differences between participants with EP-NC and healthy controls in the specific inflammatory response were observed. Participants with EP-NC prior to treatment had significantly weaker responses of proinflammatory cytokines (IL-6, TNF-α) and NK cells, and stronger IL-4 response. Anthelmintic treatment did not promote significant peripheral immunological changes at any time, although inflammation was sustained in the cerebrospinal fluid. Serum estradiol concentration significantly decreased after anthelmintic treatment among males, and cortisol correlated negatively with IL-6 and positively with IFN-γ levels. No pre-treatment immunologic or endocrinologic parameters were significantly associated with response to treatment. CONCLUSION/SIGNIFICANCE: Prior to anthelmintic treatment, EP-NC was characterized by low lymphocyte reactivity accompanied by a regulatory response, which may be involved in the lack of peripheral immunological changes during and after treatment, although a central inflammatory response was present. This weak specific peripheral response could favor the chronicity of the infection and the poor response to treatment. Our findings highlight the need for new anti-inflammatory treatment focused on the central nervous system with less systemic immunosuppressive effects.


Subject(s)
Neurocysticercosis , Male , Humans , Neurocysticercosis/drug therapy , Tumor Necrosis Factor-alpha , Interleukin-4 , Interleukin-6 , Cytokines , Killer Cells, Natural
11.
Elife ; 112022 05 09.
Article in English | MEDLINE | ID: mdl-35532105

ABSTRACT

MDGA molecules can bind neuroligins and interfere with trans-synaptic interactions to neurexins, thereby impairing synapse development. However, the subcellular localization and dynamics of MDGAs, or their specific action mode in neurons remain unclear. Here, surface immunostaining of endogenous MDGAs and single molecule tracking of recombinant MDGAs in dissociated hippocampal neurons reveal that MDGAs are homogeneously distributed and exhibit fast membrane diffusion, with a small reduction in mobility across neuronal maturation. Knocking-down/out MDGAs using shRNAs and CRISPR/Cas9 strategies increases the density of excitatory synapses, the membrane confinement of neuroligin-1, and the phosphotyrosine level of neuroligins associated with excitatory post-synaptic differentiation. Finally, MDGA silencing reduces the mobility of AMPA receptors, increases the frequency of miniature EPSCs (but not IPSCs), and selectively enhances evoked AMPA-receptor-mediated EPSCs in CA1 pyramidal neurons. Overall, our results support a mechanism by which interactions between MDGAs and neuroligin-1 delays the assembly of functional excitatory synapses containing AMPA receptors.


Subject(s)
Nerve Tissue Proteins , Receptors, AMPA , Cell Adhesion Molecules, Neuronal/metabolism , Hippocampus/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Neurons/metabolism , Receptors, AMPA/genetics , Receptors, AMPA/metabolism , Synapses/physiology
12.
Sci Total Environ ; 757: 143972, 2021 Feb 25.
Article in English | MEDLINE | ID: mdl-33321337

ABSTRACT

Land use change threatens the ecological integrity of tropical rivers and streams; however, few studies have simultaneously analyzed the taxonomic and functional responses of tropical macroinvertebrates to riparian forest conversion. Here, we used community structure, functional diversity, and stable isotope analyses to assess the impacts of riparian deforestation on macroinvertebrate communities of streams in southern Mexico. Monthly sampling during the dry season was conducted in streams with riparian forest (forest streams), and in streams with pasture dominating the riparian vegetation (pasture streams). Samples were collected for water quality (physical-chemical variables, nutrient concentrations, and total suspended solids), organic matter (leaf litter abundance and algal biomass), and macroinvertebrate abundance and diversity. Higher temperature, conductivity, suspended solids, and chlorophyll a were detected in pasture streams, while nitrate concentrations and leaf litter biomass were greater in forest streams. Macroinvertebrate density was higher in pasture sites, while no differences in taxonomic diversity and richness were found between land uses. Functional evenness was greater in forest streams, while richness and divergence were similar between land uses, despite differences in taxonomic composition. Environmental variables were associated with taxa distribution but not with functional traits, suggesting current conditions still promote redundancy in ecological function. Isotopic analyses indicated consumers in pasture streams were enriched in 13C and 15N relative to forest streams, potentially reflecting the higher algal biomass documented in pasture systems. Isotopic niches were broader and more overlapped in pasture streams, indicating more generalist feeding habits. No significant losses of taxonomic or functional diversity were detected in pasture streams. However, changes in trophic ecology suggest landscape-level processes are altering macroinvertebrate feeding habits in streams. The changes we observed in habitat, water quality, and macroinvertebrate community were related to the removal of the riparian vegetation, suggesting the structure and function of the focal systems would benefit from riparian restoration.


Subject(s)
Invertebrates , Rivers , Animals , Chlorophyll A , Ecosystem , Forests , Mexico
13.
J Clin Med ; 10(9)2021 May 07.
Article in English | MEDLINE | ID: mdl-34067025

ABSTRACT

Aortic stenosis is a progressive heart valve disorder characterized by calcification of the leaflets. Heart rate variability (HRV) analysis has been proposed for assessing the heart response to autonomic activity, which is documented to be altered in different cardiac diseases. The objective of the study was to evaluate changes of HRV in patients with aortic stenosis by an active standing challenge. Twenty-two volunteers without alterations in the aortic valve (NAV) and twenty-five patients diagnosed with moderate and severe calcific aortic valve stenosis (AVS) participated in this cross-sectional study. Ten minute electrocardiograms were performed in a supine position and in active standing positions afterwards, to obtain temporal, spectral, and scaling HRV indices: mean value of all NN intervals (meanNN), low-frequency (LF) and high-frequency (HF) bands spectral power, and the short-term scaling indices (α1 and αsign1). The AVS group showed higher values of LF, LF/HF and αsign1 compared with the NAV group at supine position. These patients also expressed smaller changes in meanNN, LF, HF, LF/HF, α1, and αsign1 between positions. In conclusion, we confirmed from short-term recordings that patients with moderate and severe calcific AVS have a decreased cardiac parasympathetic supine response and that the dynamic of heart rate fluctuations is modified compared to NAV subjects, but we also evidenced that they manifest reduced autonomic adjustments caused by the active standing challenge.

14.
Seizure ; 91: 447-455, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34340190

ABSTRACT

Neuroinflammation is probably one of the factors involved in drug resistance in people with epilepsy. Finding peripheral markers reflecting the intensity of neuroinflammation could be of great help to decide for which patients anti-inflammatory treatment might be an option. In this context, peripheral cytokines levels and lymphocyte phenotypes were assessed by ELISA and flow cytometry in 3 groups of subjects: drug resistant patients with temporal lobe epilepsy (DR-TLE), non DR-TLE patients and healthy controls. The same parameters were assessed in brain tissue in the DR-TLE group. Differences in the peripheral immune-inflammatory status between the 3 groups of subjects, and correlations between the central and peripheral immune-inflammatory status in DR-TLE patients were evaluated. Forty-one patients with DR-TLE, ten with non-DR-TLE and twenty controls were included. In the periphery, decrease in regulatory cells were observed in DR-TLE patients compared to controls. In addition, significant increase of IL-6 and IL-5 was observed in patients with epilepsy (particularly DR-TLE patients). Two groups of DR-TLE patients with significant differences in several central inflammatory parameters were identified in a cluster analysis. The inflammatory cluster was associated with a peripheral increase of CD4+CD38+ cells and different significant correlations between central and systemic inflammatory parameters were observed. Although their interpretation is not immediate, they demonstrate a clear dialogue between central and peripheral inflammatory reactions. In conclusion, our results add new elements to better understand the interactions between the central and peripheral compartments in patients with DR-TLE, and to help better define treatment options in this group of patients.


Subject(s)
Drug Resistant Epilepsy , Epilepsy, Temporal Lobe , Brain , Drug Resistance , Drug Resistant Epilepsy/drug therapy , Epilepsy, Temporal Lobe/drug therapy , Humans , Temporal Lobe
15.
Elife ; 92020 09 11.
Article in English | MEDLINE | ID: mdl-32915137

ABSTRACT

Post-transcriptional mechanisms regulating cell surface synaptic organizing complexes that control the properties of connections in brain circuits are poorly understood. Alternative splicing regulates the prototypical synaptic organizing complex, neuroligin-neurexin. In contrast to the well-studied neuroligin splice site B, little is known about splice site A. We discovered that inclusion of the positively charged A1 insert in mouse neuroligin-1 increases its binding to heparan sulphate, a modification on neurexin. The A1 insert increases neurexin recruitment, presynaptic differentiation, and synaptic transmission mediated by neuroligin-1. We propose that the A1 insert could be a target for alleviating the consequences of deleterious NLGN1/3 mutations, supported by assays with the autism-linked neuroligin-1-P89L mutant. An enrichment of neuroligin-1 A1 in GABAergic neuron types suggests a role in synchrony of cortical circuits. Altogether, these data reveal an unusual mode by which neuroligin splicing controls synapse development through protein-glycan interaction and identify it as a potential therapeutic target.


Subject(s)
Alternative Splicing , Cell Adhesion Molecules, Neuronal/metabolism , Polysaccharides/metabolism , Synapses/physiology , Animals , Female , Male , Mice , Mice, Knockout , Rats
16.
Heliyon ; 6(8): e04634, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32904272

ABSTRACT

A metabarcoding approach was performed aimed at identifying fungi associated with Delphacodes kuscheli (Hemiptera: Delphacidae), the main vector of "Mal de Río Cuarto" disease in Argentina. A total of 91 fungal genera were found, and among them, 24 were previously identified for Delphacidae. The detection of fungi that are frequently associated with the phylloplane or are endophytes, as well as their presence in digestive tracts of other insects, suggest that feeding might be an important mechanism of their horizontal transfer in planthoppers. This study draws the baseline for future research regarding mutualistic associations present in D. kuscheli as well as their physiological role in the life cycle of this important pest that might lead to developing new management strategies to keep insects populations under control.

17.
J Biosci ; 452020.
Article in English | MEDLINE | ID: mdl-33361627

ABSTRACT

Tobacco is one of the major industrial crops cultivated worldwide. Chemical control is the main method employed to reduce damage by insect pests. The use of entomopathogenic fungi represents an alternative to replace insecticides. The search for effective strains in the field constitutes a first step when developing a formulation. The objective of this work was to study genetic differences among isolates of entomopathogenic fungi obtained from tobacco grown soils using ISSR markers. The pathogenicity of the strains towards Helicoverpa gelotopoeon and Diabrotica speciosa was also assessed in order to search for a relationship between virulence and genetic diversity. Nineteen isolates were identified according to morphological features and molecular techniques as Beauveria bassiana (11) and Purpureocillium lilacinum (8). The diversity tree generated by ISSR analysis showed a high diversity among the strains. The pathogenicity towards H. gelotopoeon and D. speciosa was assessed and the logistic models generated showed that B. bassiana isolates LPSc1215 and LPSc1364 were the most pathogenic against both insect pests tested. In the diversity tree, these strains were grouped in a same cluster with a similarity level of approximately 85%, indicating a possible relationship between virulence and the band pattern generated.


Subject(s)
Fungi/genetics , Nicotiana/growth & development , Pest Control, Biological , Soil Microbiology , Animals , Beauveria/genetics , Beauveria/pathogenicity , Fungi/growth & development , Fungi/pathogenicity , Genetic Variation/genetics , Hypocreales/genetics , Hypocreales/pathogenicity , Insecta/microbiology , Insecta/parasitology , Moths/microbiology , Moths/parasitology , Phylogeny , Nicotiana/microbiology
18.
Biochem Biophys Res Commun ; 383(3): 353-7, 2009 Jun 05.
Article in English | MEDLINE | ID: mdl-19366616

ABSTRACT

MARCKS (Myristoylated alanine-rich C kinase substrate) is a ubiquitous actin regulating protein, especially abundant in the nervous system. This protein may be phosphorylated by other enzymes, particularly by proline-directed kinases, at serine and threonine residues located at different sites along its chain. We demonstrate here that the phosphorylation of chick MARCKS at serine 25, which only takes place in the nervous tissue, does not impair its association with particular plasma membrane regions such as the "detergent resistant microdomains" that also contain actin. This phosphorylated form of MARCKS is able to bind actin, and the integrity of actin filaments in cells (retina neuroblasts) is a necessary condition to sustain this phosphorylation. Taken together, these results indicate the existence of a functional interaction between actin filaments and MARCKS in cells, and particularly of an action in maintaining a phosphorylation in a region of the N-terminal moiety of MARCKS.


Subject(s)
Actins/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Proteins/metabolism , Protein Processing, Post-Translational , Retinal Neurons/metabolism , Animals , Cells, Cultured , Chick Embryo , Immunoprecipitation , Intracellular Signaling Peptides and Proteins/genetics , Membrane Proteins/genetics , Myristoylated Alanine-Rich C Kinase Substrate , Phosphorylation , Protein Structure, Tertiary , Serine/genetics , Serine/metabolism
19.
J Clin Pharmacol ; 59(4): 548-556, 2019 04.
Article in English | MEDLINE | ID: mdl-30476351

ABSTRACT

Extraparenchymal neurocysticercosis is the most severe form of cysticercosis, and response to treatment is suboptimal. We sought to determine how demographic and clinical characteristics and albendazole sulfoxide concentrations were related to cysticidal treatment response. We conducted a longitudinal study of 31 participants with extraparenchymal vesicular parasites who received the same treatment, albendazole 30 mg/kg/day for 10 days with dexamethasone 0.4 mg/kg/day for 13 days, followed by a prednisone taper. Response to treatment was determined by parasite volumes before and 6 months after treatment. Eight participants (25.8%) had a complete treatment response, 16 (51.6%) had a treatment response > 50% but < 100%, and 7 (22.6%) had a treatment response < 50%. Complete treatment response was significantly associated with higher concentrations of albendazole sulfoxide (P = .032), younger age (P = .032), fewer cysts (P = .049) and lower pretreatment parasite volume (P = .037). Higher number of previous cysticidal treatment courses was associated with a noncomplete treatment response (P = .023). Although the large proportion of participants with less than a complete response emphasizes the need to develop more efficacious pharmacologic regimens, the association of albendazole sulfoxide concentrations with treatment response highlights the importance of optimizing existing therapeutic regimens. In addition, the association of treatment response with parasite volume emphasizes the importance of early diagnosis.


Subject(s)
Albendazole/analogs & derivatives , Dexamethasone/administration & dosage , Neurocysticercosis/drug therapy , Prednisone/administration & dosage , Adult , Age Factors , Albendazole/administration & dosage , Anthelmintics/administration & dosage , Drug Therapy, Combination , Female , Humans , Longitudinal Studies , Male , Middle Aged , Neurocysticercosis/diagnosis , Neurocysticercosis/parasitology , Treatment Outcome
20.
PLoS One ; 13(5): e0196726, 2018.
Article in English | MEDLINE | ID: mdl-29715273

ABSTRACT

The neurofibromatosis type 2 (NF2) tumor suppressor protein Merlin functions as a negative regulator of cell growth and actin dynamics in different cell types amongst which Schwann cells have been extensively studied. In contrast, the presence and the role of Merlin in oligodendrocytes, the myelin forming cells within the CNS, have not been elucidated. In this work, we demonstrate that Merlin immunoreactivity was broadly distributed in the white matter throughout the central nervous system. Following Merlin expression during development in the cerebellum, Merlin could be detected in the cerebellar white matter tract at early postnatal stages as shown by its co-localization with Olig2-positive cells as well as in adult brain sections where it was aligned with myelin basic protein containing fibers. This suggests that Merlin is expressed in immature and mature oligodendrocytes. Expression levels of Merlin were low in oligodendrocytes as compared to astrocytes and neurons throughout development. Expression of Merlin in oligodendroglia was further supported by its identification in either immortalized cell lines of oligodendroglial origin or in primary oligodendrocyte cultures. In these cultures, the two main splice variants of Nf2 could be detected. Merlin was localized in clusters within the nuclei and in the cytoplasm. Overexpressing Merlin in oligodendrocyte cell lines strengthened reduced impedance in XCELLigence measurements and Ki67 stainings in cultures over time. In addition, the initiation and elongation of cellular projections were reduced by Merlin overexpression. Consistently, cell migration was retarded in scratch assays done on Nf2-transfected oligodendrocyte cell lines. These data suggest that Merlin actively modulates process outgrowth and migration in oligodendrocytes.


Subject(s)
Cell Proliferation/physiology , Neurofibromatosis 2/metabolism , Neurofibromin 2/metabolism , Oligodendroglia/metabolism , Animals , Astrocytes/metabolism , Cell Line , Cell Movement/physiology , Cell Nucleus/metabolism , Central Nervous System/metabolism , Cytoplasm/metabolism , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/metabolism , Neurogenesis/physiology , Neurons/metabolism , Schwann Cells/metabolism , Transfection/methods
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