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1.
Vet Parasitol Reg Stud Reports ; 52: 101047, 2024 Jul.
Article En | MEDLINE | ID: mdl-38880566

The variability in the expression of different P-glycoprotein (P-gp) genes in parasitic nematodes of ruminants such as Haemonchus contortus (Hco-pgp) may be caused by different factors including nematode biology, geographical region and anthelmintic pressure. This study analysed the relative expression level of 10 P-gp genes in two H. contortus (Hco-pgp) field isolates from Yucatan, Mexico: 1) PARAISO (IVM-resistant) and 2) FMVZ-UADY (IVM-susceptible). These isolates were compared with a susceptible reference isolate from Puebla, Mexico, namely "CENID-SAI". In all cases H. contortus adult males were used. The Hco-pgp genes (1, 2, 3, 4, 9, 10, 11, 12, 14 and 16) were analysed for each isolate using the RT-qPCR technique. The Hco-pgp expressions were pairwise compared using the 2-ΔΔCt method and a t-test. The PARAISO isolate showed upregulation compared to the CENID-SAI isolate for Hco-pgp 1, 3, 9, 10 and 16 (P < 0.05), and the PARAISO isolate showed upregulation vs. FMVZ-UADY isolate for Hco-pgp 2 and 9 (P < 0.05), displaying 6.58- and 5.93-fold differences (P < 0.05), respectively. In contrast, similar Hco-pgp gene expression levels were recorded for FMVZ-UADY and CENID-SAI isolates except for Hco-pgp1 (P <0.1), which presented a significant upregulation (6.08-fold). The relative expression of Hco-pgp allowed confirming the IVM-resistant status of the PARAISO isolate and the IVM-susceptible status of the FMVZ-UADY isolate when compared to the CENID-SAI reference isolate. Therefore, understanding the association between the Hco-pgp genes expression of H. contortus and its IVM resistance status could help identifying the genes that could be used as molecular markers in the diagnosis of IVM resistance. However, it is important to consider the geographic origin of the nematode isolate and the deworming history at the farm of origin.


ATP Binding Cassette Transporter, Subfamily B, Member 1 , Drug Resistance , Haemonchiasis , Haemonchus , Ivermectin , Animals , Haemonchus/drug effects , Haemonchus/genetics , Ivermectin/pharmacology , Mexico , Male , Drug Resistance/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Haemonchiasis/veterinary , Haemonchiasis/parasitology , Phenotype , Anthelmintics/pharmacology , Gene Expression , Sheep Diseases/parasitology , Sheep
2.
Pharmaceuticals (Basel) ; 17(5)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38794150

Due to the increasing populations of anthelmintic-resistant gastrointestinal nematodes and as a consequence of the adverse effects of synthetic drugs, this study focuses on the search for secondary metabolites with nematocidal activity from the edible mushroom Pleurotus djamor using The proton nuclear magnetic resonance (1H-NMR) metabolomics. The highest activity was shown by the ethyl acetate fractions of mycelium (EC50 290.8 µg/mL) and basidiomes (EC50 282.7 µg/mL). Principal component analysis (PCA) and hierarchical data analysis (HCA) of the 1H-NMR metabolic profiles data showed that the ethanolic extracts, the ethyl acetate, butanol, and water fractions from mycelium have different metabolic profiles than those from basidiomes, while low polarity (hexane) fractions from both stages of fungal development show similar profiles. Orthogonal partial least squares discriminant analysis (OPLS-DA) allowed the identification of signals in the 1H-NMR metabolic profile associated with nematocidal activity. The signals yielded via OPLS-DA and bidimensional NMR analysis allowed the identification of uracil as a component in the ethyl acetate fraction from basidiomes, with an EC50 of 237.7 µg/mL. The results obtained showed that chemometric analyses of the 1H-NMR metabolic profiles represent a viable strategy for the identification of bioactive compounds from samples with complex chemical profiles.

3.
Front Physiol ; 15: 1331852, 2024.
Article En | MEDLINE | ID: mdl-38818521

Cardiac arrhythmias cause depolarization waves to conduct unevenly on the myocardial surface, potentially delaying local components with respect to a previous beat when stimulated at faster frequencies. Despite the diagnostic value of localizing the distinct local electrocardiogram (EGM) components for identifying regions with decrement-evoked potentials (DEEPs), current software solutions do not perform automatic signal quantification. Electrophysiologists must manually measure distances on the EGM signals to assess the existence of DEEPs during pacing or extra-stimuli protocols. In this work, we present a deep learning (DL)-based algorithm to identify decrement in atrial components (measured in the coronary sinus) with respect to their ventricular counterparts from EGM signals, for disambiguating between accessory pathways (APs) and atrioventricular re-entrant tachycardias (AVRTs). Several U-Net and W-Net neural networks with different configurations were trained on a private dataset of signals from the coronary sinus (312 EGM recordings from 77 patients who underwent AP or AVRT ablation). A second, separate dataset was annotated for clinical validation, with clinical labels associated to EGM fragments in which decremental conduction was elucidated. To alleviate data scarcity, a synthetic data augmentation method was developed for generating EGM recordings. Moreover, two novel loss functions were developed to minimize false negatives and delineation errors. Finally, the addition of self-attention mechanisms and their effect on model performance was explored. The best performing model was a W-Net model with 6 levels, optimized solely with the Dice loss. The model obtained precisions of 91.28%, 77.78% and of 100.0%, and recalls of 94.86%, 95.25% and 100.0% for localizing local field, far field activations, and extra-stimuli, respectively. The clinical validation model demonstrated good overall agreement with respect to the evaluation of decremental properties. When compared to the criteria of electrophysiologists, the automatic exclusion step reached a sensitivity of 87.06% and a specificity of 97.03%. Out of the non-excluded signals, a sensitivity of 96.77% and a specificity of 95.24% was obtained for classifying them into decremental and non-decremental potentials. Current results show great promise while being, to the best of our knowledge, the first tool in the literature allowing the delineation of all local components present in an EGM recording. This is of capital importance at advancing processing for cardiac electrophysiological procedures and reducing intervention times, as many diagnosis procedures are performed by comparing segments or late potentials in subsequent cardiac cycles.

5.
Vet Parasitol ; 328: 110184, 2024 Jun.
Article En | MEDLINE | ID: mdl-38643645

This study applied the in vitro rumen exsheathment test (IVRET) to evaluate the exsheathment kinetics of Haemonchus contortus infective larvae (L3) incubated in ruminal liquor (RL) containing acetone:water extracts of Acacia pennatula (AP), Gymnopodium floribundum (GF), Havardia albicans (HA) or Lysiloma latisiliquum (LL). The role of polyphenols in the biological activity of the evaluated extracts was also determined. Larvae were incubated in RL either alone or added with a different plant extract (AP, GF, HA, or LL) at 1200 µg/mL. Polyethylene glycol (PEG) was added to block polyphenols in each treatment (RL+PEG, AP+PEG, GF+PEG, HA+PEG, and LL+PEG). After incubation times of 0, 1, 3, 6, 9, and 24 h, the exsheathment process was stopped to count the number of ensheathed and exsheathed L3. A Log-Logistic model was used to determine the L3 exsheathment kinetics in the different RL treatments. The inflection point of the respective kinetic curves, which indicates the time to reach 50 % exsheathed L3 (T50), was the only parameter that differed when comparing the exsheathment models (99 % probability of difference). The T50 values obtained for GF, HA, and LL treatments (T50 = 7.11 - 7.58 h) were higher in comparison to the T50 of RL (5.72 h) (≥ 70 % probability of difference). The L3 incubated in RL added with GF, HA, and LL extracts delayed their exsheathment at 3 and 6 h of incubation (28.71 - 48.06 % exsheathment reduction) compared to the RL treatment. The T50 value for AP, AP+PEG, GF+PEG, HA+PEG, and LL+PEG were similar to RL and RL+PEG (T50 = 5.34 - 6.97 h). In conclusion, the IVRET can be used to identify plants with the potential to delay the exsheathment of H. contortus L3 in the ruminal liquor. The acetone:water extracts of G. floribundum, H. albicans, and L. latisiliquum delayed the T50 of H. contortus exsheathment, which was evident at 3 and 6 h of incubation in ruminal liquor. The observed exsheathment delay was attributed to the polyphenol content of the extracts.


Haemonchus , Larva , Plant Extracts , Rumen , Animals , Haemonchus/drug effects , Rumen/parasitology , Plant Extracts/pharmacology , Plant Extracts/chemistry , Larva/drug effects , Haemonchiasis/veterinary , Haemonchiasis/parasitology , Anthelmintics/pharmacology , Anthelmintics/chemistry
7.
Europace ; 26(3)2024 Mar 01.
Article En | MEDLINE | ID: mdl-38530796

AIMS: Slow conduction (SC) anatomical isthmuses (AIs) are the dominant substrate for monomorphic ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (rTF). This study aimed to evaluate the utility of automated propagational analysis for the identification of SC-AI in patients with rTF. METHODS AND RESULTS: Consecutive rTF patients undergoing VT substrate characterization were included. Automated isochronal late activation maps (ILAM) were obtained with multielectrode HD Grid Catheter. Identified deceleration zones (DZs) were compared with both SC-AI defined by conduction velocity (CV) (<0.5 m/s) and isthmuses of induced VT for mechanistic correlation. Fourteen patients were included (age 48; p25-75 35-52 years; 57% male), 2 with spontaneous VT and 12 for risk stratification. Nine VTs were inducible in seven patients. Procedure time was 140 (p25-75 133-180) min and mapping time 29.5 (p25-75 20-37.7) min, using a median of 2167 points. All the patients had at least one AI by substrate mapping, identifying a total of 27 (11 SC-AIs). Isochronal late activation maps detected 10 DZs mostly in the AI between ventricular septal defect and pulmonary valve (80%). Five patients had no DZs. A significant negative correlation between number of isochrones/cm and CV was observed (rho -0.87; P < 0.001). Deceleration zones correctly identified SC-AI (90% sensitivity; 100% specificity; 0.94 accuracy) and was related to VT inducibility (P = 0.006). Deceleration zones co-localized to the critical isthmus of induced VTs in 88% of cases. No complications were observed. CONCLUSION: Deceleration zones displayed by ILAM during sinus rhythm accurately identify SC-AIs in rTF patients allowing a safe and short-time VT substrate characterization procedure.


Catheter Ablation , Pulmonary Valve , Tachycardia, Ventricular , Tetralogy of Fallot , Humans , Male , Middle Aged , Female , Tetralogy of Fallot/surgery , Heart Rate/physiology , Arrhythmias, Cardiac , Catheter Ablation/adverse effects
8.
Nutrition ; 123: 112396, 2024 Jul.
Article En | MEDLINE | ID: mdl-38554461

OBJECTIVE: Parenteral nutrition represents a therapeutic option for patients with type 3 intestinal failure. If used exclusively, parenteral nutrition has to be complete to provide all essential nutrients. The aim was to assess the availability of parenteral nutrition in all parts of the world, to better comprehend the global situation, and to prepare an action plan to increase access to parenteral nutrition. METHODS: An international survey using an electronic questionnaire was conducted in August 2019 and repeated in May 2022. An electronic questionnaire was sent to 52 members or affiliates of the International Clinical Nutrition Section of the American Society for Parenteral and Enteral Nutrition. Questions addressed the availability of parenteral nutrition admixtures and their components, reimbursement, and prescribing pre- and post-COVID-19 pandemic. All participating countries were categorized by their economic status. RESULTS: Thirty-six country representatives responded, answering all questions. Parenteral nutrition was available in all countries (100%), but in four countries (11.1%) three-chamber bags were the only option, and in six countries a multibottle system was still used. Liver-sparing amino acids were available in 18 (50%), kidney-sparing in eight (22.2%), and electrolyte-free in 11 (30.5%) countries (30.5%). In most countries (n = 28; 79.4%), fat-soluble and water-soluble vitamins were available. Trace elements solutions were unavailable in four (11.1%) countries. Parenteral nutrition was reimbursed in most countries (n = 33; 91.6%). No significant problems due to the coronavirus pandemic were reported. CONCLUSIONS: Despite the apparent high availability of parenteral nutrition worldwide, there are some factors that may have a substantial effect on the quality of parenteral nutrition admixtures. These shortages create an environment of inequality.


COVID-19 , Parenteral Nutrition , Humans , COVID-19/epidemiology , Parenteral Nutrition/statistics & numerical data , Parenteral Nutrition/methods , Surveys and Questionnaires , Global Health , SARS-CoV-2 , Pandemics , Health Services Accessibility/statistics & numerical data , Parenteral Nutrition Solutions/supply & distribution
9.
Vet Parasitol ; 327: 110135, 2024 Apr.
Article En | MEDLINE | ID: mdl-38308932

This study adapted the in vitro rumen incubation (IVRI) method to evaluate the biological activity of a Gymnopodium floribundum leaves extract against the exsheathment of Haemonchus contortus infective larvae (L3), and to determine the role of plant polyphenols on the biological activity. The incubation protocol followed the IVRI method, adding polyethylene glycol (PEG) as a polyphenol-blocking agent. The L3 were incubated in ruminal liquor (RL), ruminal liquor with PEG (RL+PEG), ruminal liquor with G. floribundum extract (RLE), and ruminal liquor with G. floribundum extract and PEG (RLE+PEG). Incubation condition controls included phosphate buffered saline (PBS), PBS with PEG (PBS+PEG), incubation medium (without ruminal liquor) (IM), and incubation medium with PEG (IM+PEG). The L3 were recovered after incubation times of 0, 1, 3, 6, 9, and 24 h (39 °C). The respective L3 exsheathment kinetics were estimated for the different treatments (RL, RL+PEG, RLE, and RLE+PEG) using Log-Logistic models. The parameters of the different models were compared to determine the impact of the extract, with or without PEG, on the L3 exsheathment kinetics. The exsheathment in PBS and PBS+PEG remained < 2.71% at each incubation time. The exsheathment in IM and IM+PEG reached 13.58% and 17.18% at 24 h, respectively. The exsheathment percentages for RLE were lower than those for RL at 3, 6 and 9 h of incubation. The inflection point, indicating the time required to reach 50% of the maximal exsheathment (T50), was the only parameter that differed between the ruminal liquor models. The T50 in RLE (7.106 h) was higher than the values obtained for RL (5.385 h) and RL+PEG (4.923 h) (99.99% probability of being different). Such delay resulted in a reduction of exsheathment in RLE of 62% at 3 h, 38% at 6 h, and 12% at 9 h, relative to RL values. When PEG was added with the extract (RLE+PEG), the T50 (5.045 h) was similar to that of RL and RL+PEG. The IVRI method was adapted as an in vitro rumen exsheathment test (IVRET). The IVRET showed that H. contortus L3 exposed to G. floribundum extract delayed their exsheathment kinetics at different time points. The exsheathment delay was attributed to the polyphenol content of the extract.


Haemonchus , Plant Extracts , Animals , Plant Extracts/pharmacology , Tannins/pharmacology , Larva , Rumen , Polyphenols/pharmacology , Polyethylene Glycols/pharmacology
10.
An Acad Bras Cienc ; 96(1): e20191190, 2024.
Article En | MEDLINE | ID: mdl-38359284

Explanations for differences in thermal biology within and between species of lizards employ concepts of phylogenetic inertia and plasticity. We compared the thermal biology of three liolaemid species in the Andean highlands in Argentina: two allopatric congeners (Phymaturus williamsi and P. aguanegra) each in syntopy with Liolaemus parvus. We predicted intra and inter-generic differences in ecophysiological traits and periods of activity at both sites, ecotypic differences between the (labile) Liolaemus populations, but predicted no interspecific differences between the (putatively conservative) Phymaturus. We determined the operative temperatures (T e), field body temperatures (T b), preferred temperatures (T pref), effectiveness of thermoregulation (E), and activity periods. As expected, P. williamsi differed from L. parvus in T b, T pref, and activity periods, likely as result of niche segregation. Contrary to predictions, the Phymaturus populations exhibited differentiation in T b and T pref, while L. parvus populations differed in T pref and E. Accordingly, Phymaturus species tend to be effective thermoregulators whereas L. parvus populations behave as good thermoregulators or thermoconformers depending on thermal conditions in fluctuating habitats. Phymaturus may be less evolutionarily conservative than previously suggested. The suite of co-evolving traits affecting thermal ecology may not be collectively conservative nor labile but rather a continuum between both evolutionary paths.


Lizards , Animals , Argentina , Phylogeny , Body Temperature , Temperature
11.
Animals (Basel) ; 14(4)2024 Feb 12.
Article En | MEDLINE | ID: mdl-38396571

We evaluated the relationship between individual and herd GIN infection level, nutrition, production performance and anemia parameters in a tropical farm context. Fifty-four female goats were monitored to assess their body condition score (BCS, nutritional status indicator), live weight (LW) and LW gain (LWG, both used as production level indicators), FAMACHA© and hematocrit (HT, both used as anemia indicators). Goats browsed for 4 h in a tropical forest and received balanced feed and chopped grass. The eggs per gram of feces (EPG) indicated the GIN burden, with fecal samples obtained at 7:00 (AM) and 15:00 h (PM.) from each goat at six sampling points during the study. The variables and their relationship with GIN burdens were analyzed using Kruskall-Wallis, ANOVA and Friedman tests and Spearman correlations. The fecal samples obtained in the AM and PM can be equally representative of parasitic burdens (similar and highly correlated). However, the EPG of individual goats from periods of 30 days apart can be considered independent. The BCS and LWG varied between sampling times (p < 0.05), whereas EPG, LW and HT did not (p > 0.05). The GIN burden was negatively correlated with HT and BCS (-0.21, p = 0.01 for each one). The individual pattern of infection demonstrates the true impact of GINs on their hosts. Additionally, feeding and nutritional status may present important variations influencing the performance of the goats more than the impact of GINs under the farm conditions of the present study. However, GIN infection contributed to the variation in goat health and productivity in this tropical farm.

12.
Exp Parasitol ; 256: 108670, 2024 Jan.
Article En | MEDLINE | ID: mdl-38092297

Ivermectin (IVM) resistance in parasitic nematodes such as Haemonchus contortus has spurred a search for substances that help to recover its efficacy. One potential agent is the natural product curcumin (CUR). In this study, CUR was combined with polyvinylpyrrolidone (PVP) (CUR/PVP) to improve its solubility and biological applicability. This study determined the effect of CUR preincubation on the effective concentration 50% (EC50) of IVM in three H. contortus isolates with different susceptibilities to IVM. The IVM EC50 was determined for three H. contortus isolates with different IVM susceptibilities using the larval migration inhibition (LMI) test. The three isolates were (i) PARAISO (IVM resistant), (ii) FMVZ-UADY (IVM susceptible), and (iii) CENID-SAI INIFAP (reference IVM susceptible). The L3 of each isolate were preincubated for 3 h with one of three concentrations of CUR (µg curcumin/mL): CONC-1 (3.67), CONC-2 (5.67), or CONC-3 (8.48). Corresponding controls were performed without CUR. The EC50 of IVM was determined for each isolate after they were exposed to the different CUR concentrations. The EC50 of IVM differed between the isolates PARAISO > FMVZ-UADY > CENID-SAI INIFAP (P < 0.05). The CUR preincubation at CONC-1 did not decrease the EC50 of IVM for any of the three isolates, suggesting a hormetic effect. By contrast, CUR preincubation at CONC-2 or CONC-3 decreased the IVM EC50 for the PARAISO isolate (P < 0.05) compared with the reference isolate and reduced the EC50 of IVM for the FMVZ-UADY and CENID-SAI INIFAP isolates below the EC50 for the CENID-SAI INIFAP isolate without CUR preincubation. In conclusion, preincubation of H. contortus L3 with CUR reduced the EC50 of IVM for field isolates classified as resistant and susceptible to IVM. The CUR preincubation reduced the IVM resistance factor in the different isolates tested.


Anthelmintics , Curcumin , Haemonchiasis , Haemonchus , Animals , Ivermectin/pharmacology , Ivermectin/therapeutic use , Anthelmintics/pharmacology , Anthelmintics/therapeutic use , Curcumin/pharmacology , Curcumin/therapeutic use , Povidone/pharmacology , Povidone/therapeutic use , Drug Resistance , Larva , Haemonchiasis/drug therapy , Haemonchiasis/veterinary
13.
Europace ; 25(11)2023 11 02.
Article En | MEDLINE | ID: mdl-37961921

AIMS: The aim of our study was to analyse the response to short-coupled atrial extrastimuli to identify areas of hidden slow conduction (HSC) and their relationship with the atrial fibrillation (AF) phenotype. METHODS AND RESULTS: Twenty consecutive patients with paroxysmal AF and persistent AF (10:10) underwent the first pulmonary vein isolation procedure. Triple short-coupled extrastimuli were delivered in sinus rhythm (SR), and the evoked response was analysed: sites exhibiting double or highly fragmented electrograms (EGM) were defined as positive for HSC (HSC+). The delta of the duration of the bipolar EGM was analysed, and bipolar EGM duration maps were built. High-density maps were acquired using a multipolar catheter during AF, SR, and paced rhythm. Spatial co-localization of HSC+ and complex fractionated atrial EGMs (CFAE) during AF was evaluated. Persistent AF showed a higher number and percentage of HSC+ than paroxysmal AF (13.9% vs. 3.3%, P < 0.001). The delta of EGM duration was 53 ± 22 ms for HSC+ compared with 13 ± 11 (10) ms in sites with negative HSC (HSC-) (P < 0.001). The number and density of HSC+ were lower than CFAE during AF (19 vs. 56 per map, P < 0.001). The reproducibility and distribution of HSC+ in repeated maps were superior to CFAE (P = 0.19 vs. P < 0.001). Sites with negative and positive responses showed a similar bipolar voltage in the preceding sinus beat (1.65 ± 1.34 and 1.48 ± 1.47 mV, P = 0.12). CONCLUSION: Functional mapping identifies more discrete and reproducible abnormal substrates than mapping during AF. The HSC+ sites in response to triple extrastimuli are more frequent in persistent AF than in paroxysmal AF.


Atrial Fibrillation , Catheter Ablation , Humans , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Reproducibility of Results , Electrophysiologic Techniques, Cardiac/methods , Heart Rate , Heart Atria
14.
Gland Surg ; 12(9): 1233-1241, 2023 Sep 25.
Article En | MEDLINE | ID: mdl-37842539

Background: There is little literature comparing intraoperative ultrasound (IOUS) with radio-guided occult lesions localization (ROLL) in nonpalpable invasive tumors in breast conserving surgery (BCS). There is a need to compare these two methods in terms of safety and efficacy. Methods: This is an observational cohort study. All patients treated with BCS for nonpalpable invasive breast cancer using IOUS from March 2016 to March 2020 were included and compared with a historical reference control group operated on using ROLL from March 2013 to March 2017. For each detection method, the ability to locate tumors intraoperatively, tumor and surgical specimen sizes, total resection volume (TRV), optimal resection volume, excess of healthy tissue resected (ETR), margin status, re-excision rate, surgical time, complications and costs were studied. Results: One hundred and fifty-eight were included, 83 with IOUS and 75 with ROLL. The mean tumor size is equivalent in both groups (11.88 mm IOUS vs. 12.29 mm ROLL, P=0.668). TRV is significantly lower with IOUS (24.92 vs. 60.32 cm3, P<0.001), and the ETR is also significantly lower in the IOUS group (21.74 vs. 58.37 cm3, P<0.001). The rate of positive margins did not differ (10.98% vs. 12.16%, P=1), nor did re-excision rate (10.98% vs. 8.11%, P=0.597). Complication rate did not differ (12.2% IOUS vs. 10.81% ROLL, P=0.808). Surgical time was shorter in IOUS (45.5 vs. 57 min, P>0.05). Conclusions: IOUS in BCS for nonpalpable invasive breast cancer is more accurate than ROLL because it decreases excision volumes with the same rate of free margins and re-excision. Also, IOUS is a more efficient and comfortable technique, and just as safe as ROLL.

15.
Ann Parasitol ; 69(1): 37-41, 2023 09 25.
Article En | MEDLINE | ID: mdl-37768300

Skrjabinodon castillensis is mentioned and illustrated here, based on specimens found in the large intestines of Liolaemus gracielae (Squamata: Liolaemidae) collected in San Juan province, Argentina. The species found is assigned to Skrjabinodon based lateral alae present in males. Lateral alae beginning midway between lips and nerve ring and ending just posterior to first pair of caudal papillae. In males, caudal alae absent, paired caudal papillae present. The species recorded in this study differs from all other species assigned to Skrjabinodon by morphology and number of tail filament spines. Skrjabinodon castillensis is the ninth species from the Neotropical realm and the only species of this genus known from Argentina.

16.
Oncogene ; 42(45): 3358-3370, 2023 Nov.
Article En | MEDLINE | ID: mdl-37773203

MYC is an oncogenic transcription factor dysregulated in about half of total human tumors. While transcriptomic studies reveal more than 1000 genes regulated by MYC, a much smaller fraction of genes is directly transactivated by MYC. Virtually all Burkitt lymphoma (BL) carry chromosomal translocations involving MYC oncogene. Most endemic BL and a fraction of sporadic BL are associated with Epstein-Barr virus (EBV) infection. The currently accepted mechanism is that EBV is the BL-causing agent inducing MYC translocation. Herein we show that the EBV receptor, CR2 (also called CD21), is a direct MYC target gene. This is based on several pieces of evidence: MYC induces CR2 expression in both proliferating and arrested cells and in the absence of protein synthesis, binds the CR2 promoter and transactivates CR2 in an E-box-dependent manner. Moreover, using mice with conditional MYC ablation we show that MYC induces CR2 in primary B cells. Importantly, modulation of MYC levels directly correlates with EBV's ability of infection in BL cells. Altogether, in contrast to the widely accepted hypothesis for the correlation between EBV and BL, we propose an alternative hypothesis in which MYC dysregulation could be the first event leading to the subsequent EBV infection.


Burkitt Lymphoma , Epstein-Barr Virus Infections , Animals , Humans , Mice , B-Lymphocytes/metabolism , Burkitt Lymphoma/pathology , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/genetics , Genes, myc , Herpesvirus 4, Human/genetics
17.
An Acad Bras Cienc ; 95(suppl 1): e20200927, 2023.
Article En | MEDLINE | ID: mdl-37646706

Several human disturbances contribute to the decrease of vertebrate species' richness and abundance, altering the processes of an ecosystem. We evaluate richness, diversity and relative abundance of species for lizard assemblages at sites with different degrees of perturbation in the center-west of the Arid Chaco region in Argentina. Between 2015 and 2018, six lizard assemblages were sampled monthly -using pitfall traps- in three areas of the Chaco, with a perturbed and an unperturbed (control) replica at each of the areas: (1) Chaco Mountain plain, (2) Chaco Mountain slope, and (3) Chaco Plains, and habitat characteristics of each study site were recorded. We captured 1446 lizards, belonging to 12 species. The perturbed area at the Chaco Mountain plain showed the greatest richness, diversity and abundance of species. In the perturbed Chaco Plains, species abundance decreased by about 50% with respect to the control site. Liolaemus chacoensis was the dominant species at all sites. Some species could be negatively affected by a total loss of arboreal strata, tree trunks and fallen leaves. Structural parameters of lizard assemblages were related to the habitat characteristics; therefore, these results provide information for the conservation and management of lands and lizard assemblages in the Arid Chaco.


Ecosystem , Lizards , Humans , Animals , Argentina , Plant Leaves , Records , Trees
18.
Sci Rep ; 13(1): 9822, 2023 06 17.
Article En | MEDLINE | ID: mdl-37330541

Biomarkers to identify women at risk of cervical cancer among those with high-risk HPV infection (hrHPV+) are needed. Deregulated expression of microRNAs (miRNAs) contributes to hrHPV-induced cervical carcinogenesis. We aimed at identifying miRNAs with the capacity to distinguish high (CIN2+) and low (≤ CIN1) grade cervical lesions. We sequenced miRNA libraries from Formalin-Fixed Paraffin-Embedded (FFPE) tissues from women with CIN2+ (n = 10) and age-matched women with ≤ CIN1 (n = 10), randomly and retrospectively selected from a trial that followed women for 24 months after a hrHPV+ test at the screening visit. Five miRNAs differentially expressed were validated by RT-qPCR in an independent set of FFPE tissues with a reviewed diagnosis of CIN2+ (n = 105) and ≤ CIN1 (n = 105). The Ingenuity Pathway Analysis (IPA) was conducted to identify mRNAs inversely correlated with the top 25 differentially expressed miRNAs. Inverse correlations with 401 unique mRNA targets were identified for fourteen of the top 25 differentially expressed miRNAs. Eleven of these miRNAs targeted 26 proteins of pathways deregulated by HPV E6 and E7 oncoproteins and two of them, miR-143-5p and miR-29a-3p, predicted CIN2+ and CIN3+ in the independent validation by RT-qPCR of FFPE tissues from hrHPV-positive women.


MicroRNAs , Papillomavirus Infections , Precancerous Conditions , Uterine Cervical Neoplasms , Humans , Female , MicroRNAs/genetics , MicroRNAs/metabolism , Human Papillomavirus Viruses , Retrospective Studies , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/pathology , Precancerous Conditions/diagnosis , Precancerous Conditions/genetics , Biomarkers , Papillomavirus Infections/complications , Papillomavirus Infections/diagnosis , Papillomavirus Infections/genetics , Papillomaviridae/genetics , Papillomaviridae/metabolism
20.
Nat Commun ; 14(1): 3445, 2023 06 10.
Article En | MEDLINE | ID: mdl-37301862

Cellular senescence is a stress response involved in ageing and diverse disease processes including cancer, type-2 diabetes, osteoarthritis and viral infection. Despite growing interest in targeted elimination of senescent cells, only few senolytics are known due to the lack of well-characterised molecular targets. Here, we report the discovery of three senolytics using cost-effective machine learning algorithms trained solely on published data. We computationally screened various chemical libraries and validated the senolytic action of ginkgetin, periplocin and oleandrin in human cell lines under various modalities of senescence. The compounds have potency comparable to known senolytics, and we show that oleandrin has improved potency over its target as compared to best-in-class alternatives. Our approach led to several hundred-fold reduction in drug screening costs and demonstrates that artificial intelligence can take maximum advantage of small and heterogeneous drug screening data, paving the way for new open science approaches to early-stage drug discovery.


Artificial Intelligence , Senotherapeutics , Humans , Aging/physiology , Cellular Senescence , Machine Learning
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