Publications by authors named "Ali Nazmi"
At day 21 of age, Ross-308 broilers were orally gavaged with 7.5 × 10 CFU/mL S. Typhimurium (n = 30), and another 30 birds were kept as the control.
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- Sorption is a key method for cleaning up oil spills, but existing absorbents lack effectiveness, prompting researchers to develop new sustainable options.
- Cellulose aerogels and foams are highlighted as promising materials due to their lightweight, porous structure and improved capacity for oil absorption, reusability, and multifunctionality.
- The review discusses recent advancements in cellulose porous materials, including preparation techniques, the impact of 3D printing for customization, and the identification of challenges and future research directions.
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- Bio-separation is key in biotechnology for isolating biological macromolecules, traditionally using bead-based and expanded bed chromatography.
- A new method, printed monolith adsorption (PMA), utilizes 3D-printed structures to facilitate direct purification from crude samples and can target specific molecules, similar to existing technologies.
- This study combined PMA with an immobilized metal ligand to selectively bind polyhistidine-tagged proteins, achieving effective purification in less time compared to commercial methods while maintaining similar binding capacities.
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- * A study was conducted with Specific-pathogen-free chickens to explore the impact of IEL during necrotic enteritis (NE), revealing changes in IEL populations and body weight gain (BWG) during infection with specific pathogens.
- * Results indicated that birds co-challenged with pathogens had significant increases in natural IEL populations shortly after infection and higher levels of pro-inflammatory cytokines, linking these immune responses to the development of subclinical NE disease. *
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- Anti-CD40 antibody treatment in Rag2-/- mice leads to significant weight loss and diarrhea, showcasing the model's similarity to inflammatory bowel disease (IBD) symptoms.
- Examination of distal colonic tissues reveals increased inflammation, altered expression of important transporters and proteins, and evidence of Paneth cell metaplasia.
- The findings suggest the potential of the anti-CD40 colitis model for studying ulcerative colitis (UC) pathophysiology due to its resemblance to key features of human IBD.
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- Sperm cryopreservation is vital for animal genetic diversity but faces challenges in avian species, particularly with the vulnerability of rooster sperm to damage.
- This study evaluates the effectiveness of different concentrations of dimethylacetamide (DMA) as a cryoprotectant on rooster sperm quality after thawing, focusing on motility, viability, and gene expression related to freeze protection.
- Results indicate that a 3% DMA concentration significantly enhances post-thawed sperm motility and health while boosting antioxidant activity and gene expression compared to higher DMA concentrations.
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- Biobased composites present a sustainable alternative to fossil-fuel-based materials, but their widespread use is limited by how people perceive them.
- This study uses the Semantic Differential method to explore how visual and tactile evaluations shape the perception of biobased composites, revealing distinct sensory clusters and relationships.
- Understanding the visual and tactile traits that influence perceptions of beauty, naturality, and value can guide the design of more appealing sustainable materials for consumers and designers.
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- * The study investigated the effects of the cryoprotectant dimethylacetamide (DMA) at varying concentrations (3%, 6%, 9%) on frozen chicken semen, finding that 6% DMA significantly improved sperm motility, viability, and overall quality.
- * While higher DMA concentrations negatively impacted antioxidant activity and certain anti-freeze genes, fertility and hatchability rates remained consistent across DMA concentrations, suggesting that using 3-6% DMA is optimal for maintaining sperm quality post-thaw.
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- Pigs are valuable for studying the immune system because their biology is similar to humans, which helps improve swine vaccine effectiveness.
- Research has primarily focused on conventional T cells (Tconvs) that respond to peptides through major histocompatibility complex (MHC) proteins, but unconventional T cells also play a crucial role in regulating these responses.
- Unconventional T cells, such as NKT cells, γδ T cells, and MAIT cells, recognize different types of molecules and exhibit distinct behaviors compared to conventional T cells, making them important for understanding pig immunity and its differences from other species like mice and humans.
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- CD4 T cell activation and differentiation are crucial for effective immune responses, but need to be tightly regulated to avoid harmful reactions.
- Granzyme B, a protease commonly linked to cytotoxic functions in certain CD4 T cells, has roles that are not fully understood, as not all granzyme B-expressing CD4 T cells exhibit cytotoxicity.
- Research shows that granzyme B-deficient CD4 T cells produce more IL-17 and lead to quicker disease onset in models of intestinal inflammation, indicating that granzyme B plays an important role in the differentiation of these T cells.
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- * Intraepithelial lymphocytes (IELs) play a critical role in this immune function, residing between intestinal epithelial cells and exhibiting diverse characteristics, including variations in their T cell receptors (TCRs).
- * This review specifically examines "unconventional" T cells in the intestinal epithelium, particularly focusing on the different types of IELs (TCRγδ+, TCRαβ+CD4+CD8αα+, and TCRαβ+CD8αα+) and their development and functions in humans and mice
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- Intestinal intraepithelial lymphocytes (IEL) are crucial for immune responses in the gut, linking the intestinal lumen and the underlying sterile environment.
- The study focuses on the role of the phosphoprotein osteopontin in maintaining the homeostasis of various IEL subpopulations, noting that its absence leads to lower cell numbers in specific IEL types due to increased apoptosis and reduced cell division.
- Findings demonstrate that osteopontin supports the survival of IEL in vitro through interaction with the CD44 receptor, highlighting the significant role of iCD8α IEL in promoting the stability of the overall IEL population.
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- Diarrhea is a key symptom of inflammatory bowel disease and is linked to reduced function of intestinal ion transporters, which has not been fully understood in T cell transfer colitis, a mouse model for Crohn's disease.
- The study investigated levels of important NaCl transporters, DRA and NHE3, in the inflamed intestines of mice that had received naïve CD4 T cell transfers.
- Results showed significant reduction in the chloride transporter DRA in the inflamed colon, while NHE3 levels remained unchanged, indicating a potential mechanism for diarrhea in this chronic inflammation model.
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- Innate CD8αα+ cells (iCD8α cells) are unique TCR-negative lymphocytes in the intestinal epithelium that play a key role in immune regulation.
- They produce osteopontin, a cytokine important for immune cell homeostasis and involved in both tissue remodeling and inflammatory responses.
- Research indicates that iCD8α cells enhance the survival of a specific type of immune cell (NKp46+NK1.1+ IEL), influencing the severity of intestinal inflammation in a mouse model, where fewer iCD8α cells lead to milder inflammatory responses.
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- Intradiol dioxygenases are bacterial enzymes that help break down catechols, which is key for degrading aromatic compounds.
- Some of these enzymes have a longer C-terminus, but this part isn’t very conserved or well-integrated into their structure.
- Truncating the C-terminus enhanced enzyme activity in certain strains while reducing it in others, suggesting this modification could be useful for boosting production of muconic and adipic acids in biotechnological applications.
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- Multifunctional enzymes, like a unique bifunctional protein in bacteria, enhance metabolic pathways by combining multiple catalytic functions, such as DAH7PS and CM, essential for producing aromatic amino acids.
- The study revealed that the two activities of the enzyme are interdependent, and separating its domains significantly reduces its function, highlighting the importance of their structural interaction.
- Additionally, the enzyme is allosterically inhibited by its product, prephenate, demonstrating that the interaction between its domains not only plays a role in catalysis but also regulates activity through conformational changes.
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- - The enzyme ATP phosphoribosyltransferase (ATP-PRT) is crucial for the first step of histidine biosynthesis in plants and microorganisms, existing in two main forms: a short-form hetero-octamer and a long-form homo-hexamer, differing in structure and regulation.
- - The study focuses on a truncated version of the long-form ATP-PRT that lacks its regulatory domain, revealing it functions as a dimer, has reduced catalytic activity, and does not respond to histidine inhibition.
- - Crystal structures of this ATP-PRT variant were obtained with substrates and the complete product, providing insights into its active site and the mechanisms of substrate positioning during the catalytic process.
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- - The study focuses on the enzyme DAH7PS in Mycobacterium tuberculosis, which shows different regulatory mechanisms based on its quaternary structure as a homotetramer.
- - Researchers created two dimeric variants of the enzyme through amino acid substitutions, which retained some activity but had decreased catalytic efficiency and disrupted allosteric regulation.
- - Molecular dynamics simulations indicated that even distant amino acid changes affected the protein's dynamics and conformation, leading to reduced efficiency and a loss of its regulatory response to ligands.
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- Endothelial cells respond to blood vessel injuries by releasing von Willebrand factor from specialized structures called Weibel-Palade bodies (WPBs).
- The study identifies a protein called Munc13-4 as crucial for linking WPBs to the plasma membrane, which is necessary for their release.
- Furthermore, the research highlights a collaboration between Munc13-4 and the annexin A2-S100A10 complex in facilitating this tethering process, enhancing WPB exocytosis during injury response.
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- - Live virus vaccines are widely used in poultry to create strong immune responses without negative side effects, and adding adjuvants can enhance these responses.
- - A study tested diatomaceous earth (DE) as an adjuvant in a live vaccine for infectious bronchitis virus (IBV) but found it did not improve immune responses or protection.
- - The research concluded that the method of vaccine administration matters, as vaccines delivered through hatchery spray were less effective than those given via the ocular route.
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- Multifunctional proteins, like DAH7PS and CM, play crucial roles in metabolism; DAH7PS starts the aromatic metabolite pathway, while CM is involved in amino acid biosynthesis, specifically for tyrosine and phenylalanine.* -
- The study shows that these two catalytic functions are in separate domains, allowing them to function independently without losing activity.* -
- The presence of prephenate, a product from the CM activity, acts as an allosteric inhibitor for DAH7PS, by altering the protein structure to block the active site, a mechanism that might be common among similar enzymes formed through gene fusion.*
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- ATP-PRT is an enzyme that plays a crucial role in the first step of histidine biosynthesis in plants and microorganisms, specifically studied here in the pathogen Campylobacter jejuni.
- The enzyme is allosterically inhibited by histidine binding to a remote site and shows competitive inhibition by AMP.
- Structural analysis revealed that ATP-PRT exists as a hexamer that changes shape between an open form with ATP and a closed form when histidine binds, supporting the idea that the active form is the hexameric structure.
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- Neisseria meningitidis 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (NmeDAH7PS) has a homotetrameric structure, but a single mutation (Arg126-Glu27) affects its stability and transforms it into a dimer in solution.
- The dimeric variant (NmeDAH7PSR126S) remains catalytically active and is allosterically inhibited similarly to the wild-type enzyme, but shows reduced thermal stability and slower activity loss over time.
- Despite crystallizing as a tetramer, the dimeric form indicates that the functional unit of NmeDAH7PS is dimeric, with the Arg126-G
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- Allostery is a process where the binding of a ligand away from the active site of a protein influences its function, and it's crucial for metabolic control; this study focuses on its role in Mycobacterium tuberculosis.
- Researchers discovered a complex interaction between two enzymes, chorismate mutase (CM) and 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS), that enhances their activity significantly when they form a hetero-octameric complex.
- The binding of phenylalanine to this complex triggers a change that reduces CM activity, allowing the bacterial pathway for aromatic amino acid biosynthesis to be finely regulated, directing the flow of intermediates toward specific amino
Article Synopsis
- - The enzyme 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase (DAH7PS) is crucial in the shikimate pathway for producing aromatic amino acids in plants and microorganisms and can take on different structural forms depending on the organism.
- - The DAH7PS from the hyperthermophilic archaebacterium Pyrococcus furiosus has been confirmed to exist as a tetramer in both crystalline and solution states, with two significant interfaces between subunits contributing to its structure.
- - A mutation in the enzyme that swaps one amino acid significantly enhances its catalytic rate, yet under standard conditions, the enzyme primarily exists as a less stable dimer, raising questions about the balance