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Journal of Biosciences 2024Bacterial species referred to as magnetotactic bacteria (MTB) biomineralize iron oxides and iron sulphides inside the cell. Bacteria can arrange themselves passively...
Bacterial species referred to as magnetotactic bacteria (MTB) biomineralize iron oxides and iron sulphides inside the cell. Bacteria can arrange themselves passively along geomagnetic field lines with the aid of these iron components known as magnetosomes. In this study, magnetosome nanoparticles, which were obtained from the taxonomically identified MTB isolate sp. PRB-1, were characterized and their antibacterial activity was evaluated. An test showed that magnetosome nanoparticles significantly inhibited the growth of sp., , and . Magnetosomes were found to contain cuboidal iron crystals with an average size of 42 nm measured by particle size analysis and scanning electron microscope analysis. The energy dispersive X-ray examination revealed that Fe and O were present in the extracted magnetosomes. The extracted magnetosome nanoparticles displayed maximum absorption at 260 nm in the UV-Vis spectrum. The distinct magnetite peak in the Fourier transform infrared (FTIR) spectroscopy spectra was observed at 574.75 cm. More research is needed into the intriguing prospect of biogenic magnetosome nanoparticles for antibacterial applications.
Topics: Anti-Bacterial Agents; Iron; Klebsiella pneumoniae; Magnetite Nanoparticles; Magnetosomes; Microbial Sensitivity Tests; Nanoparticles; Particle Size; Providencia; Pseudomonas aeruginosa; Spectroscopy, Fourier Transform Infrared; Staphylococcus
PubMed: 38726825
DOI: No ID Found -
Scientific Reports May 2024Inflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including...
Inflammatory bowel diseases (IBD) are a group of chronic inflammatory conditions of the gastrointestinal tract associated with multiple pathogenic factors, including dysregulation of the immune response. Effector CD4 T cells and regulatory CD4 T cells (Treg) are central players in maintaining the balance between tolerance and inflammation. Interestingly, genetic modifications in these cells have been implicated in regulating the commitment of specific phenotypes and immune functions. However, the transcriptional program controlling the pathogenic behavior of T helper cells in IBD progression is still unknown. In this study, we aimed to find master transcription regulators controlling the pathogenic behavior of effector CD4 T cells upon gut inflammation. To achieve this goal, we used an animal model of IBD induced by the transfer of naïve CD4 T cells into recombination-activating gene 1 (Rag1) deficient mice, which are devoid of lymphocytes. As a control, a group of Rag1 mice received the transfer of the whole CD4 T cells population, which includes both effector T cells and Treg. When gut inflammation progressed, we isolated CD4 T cells from the colonic lamina propria and spleen tissue, and performed bulk RNA-seq. We identified differentially up- and down-regulated genes by comparing samples from both experimental groups. We found 532 differentially expressed genes (DEGs) in the colon and 30 DEGs in the spleen, mostly related to Th1 response, leukocyte migration, and response to cytokines in lamina propria T-cells. We integrated these data into Gene Regulatory Networks to identify Master Regulators, identifying four up-regulated master gene regulators (Lef1, Dnmt1, Mybl2, and Jup) and only one down-regulated master regulator (Foxo3). The altered expression of master regulators observed in the transcriptomic analysis was confirmed by qRT-PCR analysis and found an up-regulation of Lef1 and Mybl2, but without differences on Dnmt1, Jup, and Foxo3. These two master regulators have been involved in T cells function and cell cycle progression, respectively. We identified two master regulator genes associated with the pathogenic behavior of effector CD4 T cells in an animal model of IBD. These findings provide two new potential molecular targets for treating IBD.
Topics: Animals; Inflammatory Bowel Diseases; Mice; Gene Regulatory Networks; CD4-Positive T-Lymphocytes; Disease Models, Animal; T-Lymphocytes, Regulatory; Mice, Inbred C57BL; Mice, Knockout; Gene Expression Regulation
PubMed: 38719901
DOI: 10.1038/s41598-024-61158-4 -
Hematology, Transfusion and Cell Therapy Apr 2024
PubMed: 38719721
DOI: 10.1016/j.htct.2024.02.024 -
European Journal of Clinical... May 2024Providencia genus is known to harbor certain opportunistic pathogens capable of causing human infections. Here, we report two strains of multidrug-resistant bacteria...
Providencia genus is known to harbor certain opportunistic pathogens capable of causing human infections. Here, we report two strains of multidrug-resistant bacteria initially identified as Providencia rettgeri by mass spectrometry, but genome analysis revealed their ANI (79.84-84.20%) and dDDH (21.1-25.6%) values to fall below the accepted species threshold for known Providencia species. We therefore propose that these isolates be recognized as a novel species, Providencia xianensis sp. nov. Alarmingly, both strains, isolated from locations far apart, exhibited resistance to last-resort antibiotics, indicating their possible wide distribution, underscoring the urgency for immediate attention and enhanced surveillance for this emerging multidrug-resistant pathogen.
PubMed: 38714595
DOI: 10.1007/s10096-024-04821-y -
Purinergic Signalling May 2024Purinergic signaling is a crucial determinant in the regulation of pulmonary vascular physiology and presents a promising avenue for addressing lung diseases. This... (Review)
Review
Purinergic signaling is a crucial determinant in the regulation of pulmonary vascular physiology and presents a promising avenue for addressing lung diseases. This intricate signaling system encompasses two primary receptor classes: P1 and P2 receptors. P1 receptors selectively bind adenosine, while P2 receptors exhibit an affinity for ATP, ADP, UTP, and UDP. Functionally, P1 receptors are associated with vasodilation, while P2 receptors mediate vasoconstriction, particularly in basally relaxed vessels, through modulation of intracellular Ca levels. The P2X subtype receptors facilitate extracellular Ca influx, while the P2Y subtype receptors are linked to endoplasmic reticulum Ca release. Notably, the primary receptor responsible for ATP-induced vasoconstriction is P2X1, with α,β-meATP and UDP being identified as potent vasoconstrictor agonists. Interestingly, ATP has been shown to induce endothelium-dependent vasodilation in pre-constricted vessels, associated with nitric oxide (NO) release. In the context of P1 receptors, adenosine stimulation of pulmonary vessels has been unequivocally demonstrated to induce vasodilation, with a clear dependency on the A receptor, as evidenced in studies involving guinea pigs and rats. Importantly, evidence strongly suggests that this vasodilation occurs independently of endothelium-mediated mechanisms. Furthermore, studies have revealed variations in the expression of purinergic receptors across different vessel sizes, with reports indicating notably higher expression of P2Y, P2Y, and P2Y receptors in small pulmonary arteries. While the existing evidence in this area is still emerging, it underscores the urgent need for a comprehensive examination of the specific characteristics of purinergic signaling in the regulation of pulmonary vascular tone, particularly focusing on the disparities observed across different intrapulmonary vessel sizes. Consequently, this review aims to meticulously explore the current evidence regarding the role of purinergic signaling in pulmonary vascular tone regulation, with a specific emphasis on the variations observed in intrapulmonary vessel sizes. This endeavor is critical, as purinergic signaling holds substantial promise in the modulation of vascular tone and in the proactive prevention and treatment of pulmonary vascular diseases.
PubMed: 38713328
DOI: 10.1007/s11302-024-10010-5 -
Indian Journal of Pediatrics May 2024
PubMed: 38710954
DOI: 10.1007/s12098-024-05145-7 -
ESC Heart Failure May 2024The viability of cardiac resynchronization therapy (CRT) in inotrope-dependent heart failure (HF) has been a matter of debate.
AIMS
The viability of cardiac resynchronization therapy (CRT) in inotrope-dependent heart failure (HF) has been a matter of debate.
METHODS AND RESULTS
We searched Medline, EMBASE, Scopus, and the Cochrane Library until 31 December 2022. Studies were included if (i) HF patients required inotropic support at CRT implantation; (ii) patients were ≥18 years old; and (iii) they provided a clear definition of 'inotrope dependence' or 'inability to wean'. A meta-analysis was performed in R (Version 3.5.1). Nineteen studies comprising 386 inotrope-dependent HF patients who received CRT (mean age 64.4 years, 76.9% male) were included. A large majority survived until discharge at 91.1% [95% confidence interval (CI): 81.2% to 97.6%], 89.3% were weaned off inotropes (95% CI: 77.6% to 97.0%), and mean discharge time post-CRT was 7.8 days (95% CI: 3.9 to 11.7). After 1 year of follow-up, 69.7% survived (95% CI: 58.4% to 79.8%). During follow-up, the mean number of HF hospitalizations was reduced by 1.87 (95% CI: 1.04 to 2.70, P < 0.00001). Post-CRT mean QRS duration was reduced by 29.0 ms (95% CI: -41.3 to 16.7, P < 0.00001), and mean left ventricular ejection fraction increased by 4.8% (95% CI: 3.1% to 6.6%, P < 0.00001). The mean New York Heart Association (NYHA) class post-CRT was 2.7 (95% CI: 2.5 to 3.0), with a pronounced reduction of individuals in NYHA IV (risk ratio = 0.27, 95% CI: 0.18 to 0.41, P < 0.00001). On univariate analysis, there was a higher prevalence of males (85.7% vs. 40%), a history of left bundle branch block (71.4% vs. 30%), and more pronounced left ventricular end-diastolic dilation (274.3 ± 7.2 vs. 225.9 ± 6.1 mL).
CONCLUSIONS
CRT appears to be a viable option for inotrope-dependent HF, with some of these patients seeming more likely to respond.
PubMed: 38710670
DOI: 10.1002/ehf2.14835 -
Heart Rhythm May 2024
PubMed: 38704078
DOI: 10.1016/j.hrthm.2024.04.096 -
Clinical Reviews in Allergy & Immunology Apr 2024Secondary prevention with penicillin aims to prevent further episodes of acute rheumatic fever and subsequent development of rheumatic heart disease (RHD). Penicillin... (Meta-Analysis)
Meta-Analysis Review
Secondary prevention with penicillin aims to prevent further episodes of acute rheumatic fever and subsequent development of rheumatic heart disease (RHD). Penicillin allergy, self-reported by 10% of the population, can affect secondary prevention programs. We aimed to assess the role for (i) routine penicillin allergy testing and the (ii) safety of penicillin allergy delabeling approaches in this context. We searched MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, WHO ICTRP, ISRCTN, and CPCI-S to identify the relevant reports. We found 2419 records, but no studies addressed our initial question. Following advice from the WHO-Guideline committee and experts, we identified 6 manuscripts on allergy testing focusing on other populations showing that the prevalence of allergy confirmed by testing was low and the incidence of life-threatening reactions to BPG was very low (< 1-3/1000 individuals treated). A subsequent search addressed penicillin allergy delabeling. This found 516 records, and 5 studies addressing the safety of direct oral drug challenge vs. skin testing followed by drug administration in patients with suspected penicillin allergy. Immediate allergic reactions of minor severity were observed for a minority of patients and occurred less frequently in the direct drug challenge group: 2.3% vs. 11.5%; RR = 0.25, 95%CI 0.15-0.45, P < 0.00001, I = 0%. No anaphylaxis or deaths were observed. Severe allergic reactions to penicillin are extremely rare and can be recognized and dealt by trained healthcare workers. Confirmation of penicillin allergy diagnosis or delabeling using direct oral drug challenge or penicillin skin testing seems to be safe and is associated with a low rate of adverse reactions.
Topics: Humans; Drug Hypersensitivity; Penicillins; Skin Tests; Practice Guidelines as Topic; World Health Organization; Anti-Bacterial Agents
PubMed: 38696031
DOI: 10.1007/s12016-024-08988-2 -
ZooKeys 2024is the only myriapod of the class Symphyla known from Chile. This garden centipede, or pseudocentipede, was described more than 120 years ago based on morphologically...
is the only myriapod of the class Symphyla known from Chile. This garden centipede, or pseudocentipede, was described more than 120 years ago based on morphologically incomplete specimens collected in central Chile, a well-known biodiversity hotspot. In this study, we redescribe this species based on morphologically complete specimens collected near the type locality using scanning electron microscope images. Our study provides the description of diagnostic characters hitherto unknown in this species such as macrochaetae of the tergites and spinnerets of the cerci. We also include a new record from central Chile and discuss the presumed presence of this species in Argentina and Madagascar.
PubMed: 38693971
DOI: 10.3897/zookeys.1198.119723