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The rise of antibiotic-resistant bacterial strains represents an important challenge for global health, underscoring the critical need for innovative strategies to confront this threat. Natural products and their derivatives have emerged as a promising reservoir for drug discovery. The social amoeba Dictyostelium discoideum is a potent model organism in this effort. Employing this invertebrate model, we introduce a novel perspective to investigate natural plant extracts in search of molecules with potential antivirulence activity. Our work established an easy-scalable developmental assay targeting a virulent strain of Klebsiella pneumoniae, with Helenium aromaticum as the representative plant. The main objective was to identify tentative compounds from the Helenium aromaticum extract that attenuate the virulence of K. pneumoniae virulence without inducing cytotoxic effects on amoeba cells. Notably, the methanolic root extract of H. aromaticum fulfilled these prerequisites compared to the dichloromethane extract. Using UHPLC Q/Orbitrap/ESI/MS/MS, 63 compounds were tentatively identified in both extracts, 47 in the methanolic and 29 in the dichloromethane, with 13 compounds in common. This research underscores the potential of employing D. discoideum-assisted pharmacognosy to discover new antivirulence agents against multidrug-resistant pathogens.

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Inflammation and mucus production are prevalent characteristics of chronic respiratory conditions, such as asthma and chronic chronic obstructive pulmonary disease (COPD). Biological co-factors, including bacteria, viruses, and fungi, may exacerbate these diseases by activating various pathways associated with airway diseases. An example is the fungus Pneumocystis, which is linked to severe COPD in human patients. Recent evidence has demonstrated that Pneumocystis significantly enhanced inflammation and mucus hypersecretion in a rat model of elastase-induced COPD. The present study specifically aims to investigate two additional aspects associated with the pathology induced by Pneumocystis infection: inflammation and collagen deposition around airways. To this end, the focus was to investigate the role of the IL-1ß pro-inflammatory pathway during Pneumocystis infection in COPD rats. Several airway pathology-related features, such as inflammation, mucus hypersecretion, and fibrosis, were evaluated using histological and molecular techniques. COPD animals infected with Pneumocystis exhibited elevated inflammation levels, including a synergistic increase in IL-1ß and Cox-2. Furthermore, protein levels of the IL-1ß-dependent transcription factor cAMP response element-binding (CREB) showed a synergistic elevation of their phosphorylated version in the lungs of COPD animals infected with Pneumocystis, while mucus levels were notably higher in the airways of COPD-infected animals. Interestingly, a CREB responsive element (CRE) was identified in the Muc5b promoter. The presence of CREB in the Muc5b promoter was synergistically increased in COPD animals infected with Pneumocystis compared to other experimental groups. Finally, an increment of deposited collagen was identified surrounding the airways of COPD animals infected with Pneumocystis compared with the other experimental animal groups and correlated with the increase of Tgfß1 mRNA levels. These findings emphasize the role of Pneumocystis as a potential biological co-factor in chronic respiratory diseases like COPD or asthma, warranting new perspectives in the treatment of chronic respiratory diseases.

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The emergence of hypervirulent Klebsiella pneumoniae (hvKP) strains poses a significant threat to public health due to high mortality rates and propensity to cause severe community-acquired infections in healthy individuals. The ability to form biofilms and produce a protective capsule contributes to its enhanced virulence and is a significant challenge to effective antibiotic treatment. Polyphosphate kinase 1 (PPK1) is an enzyme responsible for inorganic polyphosphate synthesis and plays a vital role in regulating various physiological processes in bacteria. In this study, we investigated the impact of polyP metabolism on the biofilm and capsule formation and virulence traits in hvKP using Dictyostelium discoideum amoeba as a model host. We found that the PPK1 null mutant was impaired in biofilm and capsule formation and showed attenuated virulence in D. discoideum compared to the wild-type strain. We performed a proteomic analysis to gain further insights into the underlying molecular mechanism. The results revealed that the PPK1 mutant had a differential expression of proteins involved in capsule synthesis (Wzi-Ugd), biofilm formation (MrkC-D-H), synthesis of the colibactin genotoxin precursor (ClbB), as well as proteins associated with the synthesis and modification of lipid A (ArnB-LpxC-PagP). These proteomic findings corroborate the phenotypic observations and indicate that the PPK1 mutation is associated with impaired biofilm and capsule formation and attenuated virulence in hvKP. Overall, our study highlights the importance of polyP synthesis in regulating extracellular biomolecules and virulence in K. pneumoniae and provides insights into potential therapeutic targets for treating K. pneumoniae infections.

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This paper evaluates how the July 2005 London terrorist attacks affected Muslim teenagers' education plans and decisions. The attacks triggered a violent backslash against the Muslim community, which could have affected their incentives to continue in full-time education. I examine panel data on educational attitudes from the "Next Steps" Survey in England and use the month the survey was administered to divide individuals into treatment and control groups. I find that the attacks negatively affected the education plans of Muslims, but not those of any other major religious group. The probability of planning to continue in non-compulsory full-time education decreased by around 4.4% points for Muslims after the attacks. This corresponds to a 69% increase in individuals who were not sure whether to continue or drop out of full-time education. However, this change in plans appears to be a temporary reaction, since it did not affect students' actual decisions two years later.

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Potato cyst nematodes (PCNs; Globodera spp.) cause significant losses in worldwide cultivated potato (Solanum tuberosum) crops. In Colombia, PCN was first reported in 1970 (Baeza 1972), although this report lacked a comprehensive species description and diagnosis. After that, G. pallida has been the only PCN species reported affecting potatoes in the main producing regions of Colombia (Evans et al. 1975; Nieto et al. 1983; Vallejo et al. 2021). However, in the survey conducted by Vallejo et al. (2021), a single sample from Chocontá, Cundinamarca in the central region of the country (N 5,22396046668291, W -73,6571338400244) showed molecular characters similar to G. rostochiensis. As correct identification is essential for effective pest management, the location was re-sampled in September 2022. From the soil samples collected, PCN cysts and second-stage juveniles (J2s) were retrieved from soil using Fenwick and centrifugation methods, respectively. Morphometric characters of cysts (n = 53) were consistent with G. rostochiensis, with a length without neck (L) ranging from 451 to 614 µm (X̅ = 546.9 ± 20.3 µm), width (W) from 424 to 658 µm (X̅ = 546.9 ± 25.5 µm) and L/W ratio was 1.00 ± 0.02. Distance from anus to vulva varied from 41 to 109 µm (X̅ =75.67 ± 13.8 µm), Granek's ratio from 2.3 to 5.5 µm (X̅ = 3.89 ± 0.7 µm), and the number of cuticular ridges between the vulva and the anus were 14 to 20 (X̅ = 16.19 ± 1.7). The second-stage juvenile (n = 90) length ranged from 394 to 547 µm (X̅ = 495.62 ± 31.0 µm), the stylet length varied from 18 to 24 µm (X̅ = 21.21 ± 0.9 µm) with rounded knobs. The length of the hyaline tail ranged from 20 - 31 µm (X̅ = 24.09 ± 1.92) and the true tail from 31- 56 µm (X̅ = 48.30 ± 5.71 µm). Molecular analyses confirmed morphological identification. DNA was extracted from cysts and J2s. PCR was performed for the 28S rDNA D2-D3 segment using primers D2A and D3B (Subbotin et al. 2006), and for the mitochondrial COI gene region using primers JB3 and JB5 (Derycke et al. 2005). BLAST analyses of target 28S rDNA D2-D3 sequences (OP293373-OP293380) showed 100% identity of the 658 bp to other sequences on Genbank, including isolates from Turkey, United Kingdom, and Iran (MK311329.1, MG994942.1, KU297659.1, and KU297658.1). Similarly, the target COI region sequences (OP297993-OP298001) were 100% identical to the 407 bp of G. rostochiensis POT01 isolate from Germany, and 99.75% identical to voucher NRM67 from Indonesia, and isolate CD2200 from USA (MF773722.1, MT240262.1, and MN095979.1). Phylogenetic analysis of both gene regions strongly supported G. rostochiensis, with the Colombian sequences clustering with MH399815.1, and KU297654.1 isolates for the COI and 28S regions, respectively (Fig. 1S). In addition, a pathogenicity test was conducted in the greenhouse. For this, ten cysts were inoculated to potato plants of Criolla variety grown in 5 pots of 15 cm diameter with sterile soil and sand (1:1). Noninoculated plants served as controls (three replicates each). After three months, 54 ± 23 cysts/100 g of soil were isolated from inoculated plants (Fig. 2S), resulting in a reproduction factor (R=Pf/Pi) of 4.54 ± 0.86, while no yellow females or cysts were observed on the control plants. To our knowledge, this is the first report of G. rostochiensis in Colombia. This is an important pest that causes serious yield losses of potatoes and is a quarantine nematode in many countries (EPPO 2017). Further studies are necessary to prevent the spread of this PCN species in the main producing potato regions of Colombia.

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Photoplethysmography (PPG) signals have been widely used in evaluating cardiovascular biomarkers, however, there is a lack of in-depth understanding of the remote usage of this technology and its viability for underdeveloped countries. This study aims to quantitatively evaluate the performance of a low-cost wireless PPG device in detecting ultra-short-term time-domain pulse rate variability (PRV) parameters in different postures and breathing patterns. A total of 30 healthy subjects were recruited. ECG and PPG signals were simultaneously recorded in 3 min using miniaturized wearable sensors. Four heart rate variability (HRV) and PRV parameters were extracted from ECG and PPG signals, respectively, and compared using analysis of variance (ANOVA) or Scheirer-Ray-Hare test with post hoc analysis. In addition, the data loss was calculated as the percentage of missing sampling points. Posture did not present statistical differences across the PRV parameters but a statistical difference between indicators was found. Strong variation was found for the RMSSD indicator in the standing posture. The sitting position in both breathing patterns demonstrated the lowest data loss (1.0 ± 0.6 and 1.0 ± 0.7) and the lowest percentage of different factors for all indicators. The usage of commercial PPG and BLE devices can allow the reliable extraction of the PPG signal and PRV indicators in real time.

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Inflammation and mucus hypersecretion are frequent pathology features of chronic respiratory diseases such as asthma and COPD. Selected bacteria, viruses and fungi may synergize as co-factors in aggravating disease by activating pathways that are able to induce airway pathology. Pneumocystis infection induces inflammation and mucus hypersecretion in immune competent and compromised humans and animals. This fungus is a frequent colonizer in patients with COPD. Therefore, it becomes essential to identify whether it has a role in aggravating COPD severity. This work used an elastase-induced COPD model to evaluate the role of Pneumocystis in the exacerbation of pathology, including COPD-like lung lesions, inflammation and mucus hypersecretion. Animals infected with Pneumocystis developed increased histology features of COPD, inflammatory cuffs around airways and lung vasculature plus mucus hypersecretion. Pneumocystis induced a synergic increment in levels of inflammation markers (Cxcl2, IL6, IL8 and IL10) and mucins (Muc5ac/Muc5b). Levels of STAT6-dependent transcription factors Gata3, FoxA3 and Spdef were also synergically increased in Pneumocystis infected animals and elastase-induced COPD, while the levels of the mucous cell-hyperplasia transcription factor FoxA2 were decreased compared to the other groups. Results document that Pneumocystis is a co-factor for disease severity in this elastase-induced-COPD model and highlight the relevance of STAT6 pathway in Pneumocystis pathogenesis.

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Duddingtonia flagrans is a nematophagous fungus employed as a biocontrol agent of gastrointestinal nematodes in ruminants. After oral ingestion and passage through the digestive tract of animals, this microorganism captures the nematodes in the feces. The drastic conditions of ruminant digestive tract could affect fungi chlamydospores and therefore biocontrol activity. The aim of this study was to evaluate in vitro the effect of four ruminant digestive segments on the concentration and nematode predatory ability of a Colombian native strain of D. flagrans. The sequential four-step methodology proposed evaluated conditions of the oral cavity, rumen, abomasum, and small intestine such as pH (2, 6, 8), enzymes (pepsin, pancreatin), temperature (39 °C), and anaerobiosis comparing short (7 h) and long (51 h) exposure times. The results showed that the nematode predatory ability of the fungi is affected by sequential exposure to gastrointestinal segments and this effect depends on the exposure time to those conditions. After short exposure (7 h) through the four ruminant digestive segments, the fungi had a nematode predatory ability of 62%, in contrast, after long exposure (51 h) the nematode predatory ability was lost (0%). Moreover, the number of broken chlamydospores was higher in the long-exposure assay.

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The primary mechanism for neuron death after an ischemic stroke is excitotoxic injury. Excessive depolarization leads to NMDA-mediated calcium entry to the neuron and, subsequently, cellular death. Therefore, the inhibition of the NMDA channel has been proposed as a neuroprotective measure in ischemic stroke. The high morbimortality associated with stroke warrants new therapies that can improve the functional prognosis of patients. Memantine is a non-competitive NMDA receptor antagonist which has gained attention as a potential drug for ischemic stroke. Here we analyze the available preclinical and clinical evidence concerning the use of memantine following an ischemic stroke. Preclinical evidence shows inhibition of the excitotoxic cascade, as well as improved outcomes in terms of motor and sensory function with the use of memantine. The available clinical trials of high-dose memantine in patients poststroke have found that it can improve patients' NIHSS and Barthel index and help patients with poststroke aphasia and intracranial hemorrhage. These results suggest that memantine has a clinically relevant neuroprotective effect; however, small sample sizes and other study shortcomings limit the impact of these findings. Even so, current studies show promising results that should serve as a basis to promote future research to conclusively determine if memantine does improve the outcomes of patients' post-ischemic stroke. We anticipate that future trials will fill current gaps in knowledge, and these latter results will broaden the therapeutic arsenal for clinicians looking to improve the prognosis of patients poststroke.

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PURPOSE: Internal carotid artery (ICA) aneurysm treatment with a flow diverter (FD) has shown an adequate efficacy and safety profile, presenting high complete occlusion or near occlusion rates with low complications during follow-up. The purpose of this study was to evaluate the efficacy and safety of FD treatment in non-ruptured internal carotid aneurysms. MATERIALS AND METHODS: This is a retrospective, single-center, observational study evaluating patients diagnosed with unruptured ICA aneurysms treated with an FD between January 1, 2014, and January 1, 2020. We analyzed an anonymized database. The primary effectiveness endpoint was complete occlusion (O'Kelly-Marotta D, OKM-D) of the target aneurysm through 1-year follow-up. The safety endpoint was the evaluation of modified Rankin Scale (mRS) 90 days after treatment, considering a favorable outcome an mRS 0-2. RESULTS: A total of 106 patients were treated with an FD, 91.5% were women; the mean follow- up was 427.2±144.8 days. Technical success was achieved in 105 cases (99.1%). All patients included had 1-year follow-up digital subtraction angiography control; 78 patients (73.6%) completed the primary efficacy endpoint by achieving total occlusion (OKM-D). Giant aneurysms had a higher risk of not achieving complete occlusion (risk ratio, 3.07; 95% confidence interval, 1.70 - 5.54]). The safety endpoint of mRS 0-2 at 90 days was accomplished in 103 patients (97.2%). CONCLUSION: Treatment of unruptured ICA aneurysms with an FD showed high 1-year total occlusion results, with very low morbidity and mortality complications.