Hasil untuk "Biochemistry"

R. Germain, D. Margulies

C. Anthony

Practical Clinical Biochemistry. By Harold Varley, M.Sc., F.R.I.C.; Second Edition; 1958. London: William Heinemann (Medical Books), Limited. 8½“ × 5½“, pp. 643, with many illustrations. Price: 42s. (English).

M. Hatch

John Shi, Jian-xing Yu, Joseph Pohorly et al.

A. Sauve, C. Wolberger, V. Schramm et al.

W. Martin, M. Russell

L. Barsanti, P. Gualtieri

Mangesh Vaidya, V. R. Patodkar, Prajakta Kuralkar et al.

Livestock-generated methane, particularly from cattle, was a significant contributor to climate change. Methane emissions from ruminant animals, such as cows and sheep, are primarily caused by the microbial fermentation of food in their digestive systems, a process known as enteric fermentation by making this process a prime source of greenhouse gas emissions in animal production. Considerable knowledge gaps existed in animal agriculture regarding effective strategies for mitigating these emissions while maintaining productivity. A key factor was the uncertainty surrounding methods for estimating emission rates, each having inherent limitations. For example, the suitability of the GreenFeed system varied based on specific experiment objectives. Compared to respiration chambers and the sulfur hexafluoride tracer method, the The GreenFeed system often required more time and a larger number of animals for treatment comparisons due to higher within-day variances. It measured numerous short-term methane emissions from individual animals at various times throughout the day over several days. Recent advancements focused on improving accuracy, ease of use, and cost-effectiveness, essential for better monitoring of greenhouse gases. Traditional methods, such as respiration chambers, while accurate, were costly and impractical for field measurements. The GreenFeed system’s software facilitated control over feed availability timing and CH4 measurement allocation. Therefore, careful planning was necessary to ensure accurate estimates of methane production. This review emphasized the need for effective measurement techniques to mitigate methane emissions from livestock.

Shilpi Goenka

<b>Background/Objectives:</b> Oleuropein (OLP), the key bioactive in olive leaf extracts, has demonstrated various biological benefits. We previously reported on the pro-melanogenic action with increased dendricity of a patented olive leaf extract (Benolea^®) that was standardized to 16–24% OLP. In this study, purified OLP was evaluated to identify if it might be the bioactive responsible for the stimulating effects on melanocytes. Moreover, previous studies on OLP have never reported the effects on melanocyte dendricity or melanin export in the medium. <b>Methods:</b> Herein, the effect of OLP on melanogenesis was first evaluated using the B16F10 cell model and validated using the physiological model of normal human melanocytes from Caucasian (lightly pigmented; LP) and Asian (moderately pigmented; MP) skin. The effects of OLP on melanin export in LP and MP cells were indirectly evaluated by dendricity indices. <b>Results:</b> OLP lowered the intracellular melanin content in B16F10 cells by 26.36%, 24.48%, and 27.71% at 100, 150, and 200 µg/mL (all <i>p</i> < 0.01), respectively, with no effect on the intracellular melanin contents of LP or MP cells. OLP treatment did not influence tyrosinase activity in B16F10 cells or MP cells but significantly enhanced the activity in LP cells. The measurement of extracellular melanin showed significantly higher levels for all three cells, although the levels were considerably higher in MP cells, after the adjustment for OLP autoxidation observed in the cell-free system, which caused melanin-like brown coloration. Furthermore, OLP induced morphological alterations of extended dendrites of B16F10 cells that were retained in LP and MP cells. The quantitation of the dendricity of cells treated with OLP at 200 μg/mL revealed that the total dendrite length was increased by 35.24% (<i>p</i> < 0.05) in LP cells and by 58.45% (<i>p</i> < 0.001) in MP cells without any change in the dendrite number. <b>Conclusions:</b> This is the first study to demonstrate the novel finding that OLP possesses a hitherto unreported unique capacity to stimulate melanocyte dendricity, hence establishing the efficacy for use in increasing human pigmentation. Our findings show significance, with a potential application of the compound OLP for addressing human hypopigmentation disorders in clinical settings or for cosmetic uses related to sunless tanning.

Xiao-Song Chen, Feng Chen, Shu-Jia He et al.

Aim To investigate the comprehensive expression levels and possible molecular mechanisms of Anaphase Promoting Complex Subunit 1 (ANAPC1) in lung squamous cell carcinoma (LUSC).Methods Data from 2,031 samples were combined to evaluate ANAPC1 mRNA levels, and 118 samples were collected for immunohistochemical (IHC) analysis. High-expression co-expressed genes (HECEGs) associated with ANAPC1 were analyzed for signaling pathways. Clinical significance, immune computations, and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) validation of ANAPC1’s role in LUSC were assessed. Molecular docking evaluated binding affinity with potential therapeutics.Results ANAPC1 mRNA was significantly upregulated in LUSC (SMD = 1.97, 95% CI [1.26–2.67]). Protein-level analysis confirmed this upregulation (p < 0.001). Most HECEGs associated with ANAPC1 were enriched in cell cycle pathways. Higher ANAPC1 expression correlated with poorer survival in LUSC patients (HR = 1.11, 95% CI: 1–1.49). ANAPC1 expression was higher in males and N1-stage vs. females and N0-stage; lower in grade I vs. II/III. Overexpression reduces immune cell infiltration and immunotherapy effectiveness, while knockdown inhibits cell proliferation. Drug sensitivity and docking analyses identified tenovin-1, carboxyatractyloside, and phycocyanobilin as potential antitumor agents targeting ANAPC1.Conclusion The elevated expression of ANAPC1 might play a role in LUSC advancement and progression through its participation in cell growth-related pathways.

Isaura Borges-Silva, Marluce da Cunha Mantovani, Minh Danh Anh Luu et al.

Pancreatic islet transplantation offers great promise for the treatment of type 1 diabetes, yet the functional decline of islets after isolation remains a major obstacle. Increasing evidence highlights the endoplasmic reticulum (ER) as a critical regulator of islet cell survival under stress. We explored how ex vivo culture conditions affect encapsulated islet resilience under ER-stress. Two conditions were assessed: (i) incorporation of decellularized porcine pancreatic extracellular matrix (ECM) into alginate microcapsules, and (ii) free-fall dynamic pre-conditioning culture. Human islets were encapsulated in alginate with or without ECM, cultured under static or dynamic conditions, and exposed to acute ER-stress followed or not by a recovery period. Dynamic culture preserved viability and enhanced glucose responsiveness. ECM-containing capsules showed reduced inflammatory marker expression, while encapsulation in alginate-only capsules led to more pronounced changes associated with ECM remodeling. Under ER-stress, the dynamic culture, especially combined with ECM, maintained cell function and reduced cell death. Gene profiles indicated improved stress adaptation and ECM remodeling. These results highlight ECM enrichment and dynamic culture as good strategies to maintain islet survival and functionality.

Lincy Koodaly, Erika Friedmann, Nancy R. Gee et al.

<b>Background:</b> The growth of the older adult population calls for innovative and cost-effective ways of promoting their physical, psychological, and cognitive health. Human–animal interaction, including pet ownership, is related to positive and negative aspects of human health. Not all pet owners respond in the same way. The levels of pet attachment and pets’ influence on their owners’ lives could moderate the relationship between psychological status and health outcomes. <b>Purpose:</b> We examined the moderating role of pet attachment in the relationships of psychological status (mental wellbeing, happiness, anxiety, depression) to physical function (physical wellbeing, usual- and rapid-gait speeds, physical performance battery) in community-residing older adult pet owners. <b>Methods:</b> A cross-sectional, secondary analysis of pet-owning older adult participants in the Baltimore Longitudinal Study of Aging (n = 178). <b>Results:</b> In regression analyses, controlling for age, gender, and comorbidities, pet attachment and pet influence moderated the relationships of physical wellbeing to mental wellbeing and anxiety (<i>p</i> < 0.05). Pet influence also moderated the relationship between anxiety and usual gait speed (<i>p</i> < 0.05). <b>Conclusions:</b> Greater attachment and influence buffer the relationship of perceptions of poor mental function with perceptions of poor physical wellbeing suggesting one mechanism for health benefits of human-animal interaction.

Sevvandi Kandanaarachchi, Ziqi Xu, Stefan Westerlund et al.

Many dynamic processes such as telecommunication and transport networks can be described through discrete time series of graphs. Modelling the dynamics of such time series enables prediction of graph structure at future time steps, which can be used in applications such as detection of anomalies. Existing approaches for graph prediction have limitations such as assuming that the vertices do not to change between consecutive graphs. To address this, we propose to exploit time series prediction methods in combination with an adapted form of flux balance analysis (FBA), a linear programming method originating from biochemistry. FBA is adapted to incorporate various constraints applicable to the scenario of growing graphs. Empirical evaluations on synthetic datasets (constructed via Preferential Attachment model) and real datasets (UCI Message, HePH, Facebook, Bitcoin) demonstrate the efficacy of the proposed approach.

S. Penuela, Ruchi Gehi, D. Laird

Three family members compose the pannexin family of channel-forming glycoproteins (Panx1, Panx2 and Panx3). Their primary function is defined by their capacity to form single-membrane channels that are regulated by post-translational modifications, channel intermixing, and sub-cellular expression profiles. Panx1 is ubiquitously expressed in many mammalian tissues, while Panx2 and Panx3 appear to be more restricted in their expression. Paracrine functions of Panx1 as an ATP release channel have been extensively studied and this channel plays a key role, among others, in the release of "find-me" signals for apoptotic cell clearance. In addition Panx1 has been linked to propagation of calcium waves, regulation of vascular tone, mucociliary lung clearance, taste-bud function and has been shown to act like a tumor suppressor in gliomas. Panx1 channel opening can also be detrimental, contributing to cell death and seizures under ischemic or epileptic conditions and even facilitating HIV-1 viral infection. Panx2 is involved in differentiation of neurons while Panx3 plays a role in the differentiation of chondrocytes, osteoblasts and the maturation and transport of sperm. Using the available Panx1 knockout mouse models it has now become possible to explore some of its physiological functions. However, given the potential for one pannexin to compensate for another it seems imperative to generate single and double knockout mouse models involving all three pannexins and evaluate their interplay in normal differentiation and development as well as in malignant transformation and disease. This article is part of a Special Issue entitled: The communicating junctions, roles and dysfunctions.

Daniella Bar-Lev, Tuvi Etzion, Eitan Yaakobi et al.

Enzymatic DNA labeling is a powerful tool with applications in biochemistry, molecular biology, biotechnology, medical science, and genomic research. This paper contributes to the evolving field of DNA-based data storage by presenting a formal framework for modeling DNA labeling in strings, specifically tailored for data storage purposes. Our approach involves a known DNA molecule as a template for labeling, employing patterns induced by a set of designed labels to represent information. One hypothetical implementation can use CRISPR-Cas9 and gRNA reagents for labeling. Various aspects of the general labeling channel, including fixed-length labels, are explored, and upper bounds on the maximal size of the corresponding codes are given. The study includes the development of an efficient encoder-decoder pair that is proven optimal in terms of maximum code size under specific conditions.

Yazheng Liu, Xi Zhang, Sihong Xie

Graphs are ubiquitous in social networks and biochemistry, where Graph Neural Networks (GNN) are the state-of-the-art models for prediction. Graphs can be evolving and it is vital to formally model and understand how a trained GNN responds to graph evolution. We propose a smooth parameterization of the GNN predicted distributions using axiomatic attribution, where the distributions are on a low-dimensional manifold within a high-dimensional embedding space. We exploit the differential geometric viewpoint to model distributional evolution as smooth curves on the manifold. We reparameterize families of curves on the manifold and design a convex optimization problem to find a unique curve that concisely approximates the distributional evolution for human interpretation. Extensive experiments on node classification, link prediction, and graph classification tasks with evolving graphs demonstrate the better sparsity, faithfulness, and intuitiveness of the proposed method over the state-of-the-art methods.

S. Young, R. Zechner

All organisms use fatty acids (FAs) for energy substrates and as precursors for membrane and signaling lipids. The most efficient way to transport and store FAs is in the form of triglycerides (TGs); however, TGs are not capable of traversing biological membranes and therefore need to be cleaved by TG hydrolases ("lipases") before moving in or out of cells. This biochemical process is generally called "lipolysis." Intravascular lipolysis degrades lipoprotein-associated TGs to FAs for their subsequent uptake by parenchymal cells, whereas intracellular lipolysis generates FAs and glycerol for their release (in the case of white adipose tissue) or use by cells (in the case of other tissues). Although the importance of lipolysis has been recognized for decades, many of the key proteins involved in lipolysis have been uncovered only recently. Important new developments include the discovery of glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), the molecule that moves lipoprotein lipase from the interstitial spaces to the capillary lumen, and the discovery of adipose triglyceride lipase (ATGL) and comparative gene identification-58 (CGI-58) as crucial molecules in the hydrolysis of TGs within cells. This review summarizes current views of lipolysis and highlights the relevance of this process to human disease.

Li Jiayang, Dai Hai-Qiang

Alanood S. Almurshedi, Thanaa A. El-Masry, Hend Selim et al.

Abstract Background Marine macroalgae have gained interest recently, mostly due to their bioactive components. Polycladia crinita is an example of marine macroalgae from the Phaeophyceae class, also known as brown algae. They are characterized by a variety of bioactive compounds with valuable medical applications. The prevalence of such naturally active marine resources has made macroalgae-mediated manufacturing of nanoparticles an appealing strategy. In the present study, we aimed to evaluate the antioxidant and anti-inflammatory features of an aqueous extract of Polycladia crinita and biosynthesized P. crinita selenium nanoparticles (PCSeNPs) via a carrageenan-induced rat paw edema model. The synthesized PCSeNPs were fully characterized by UV–visible spectroscopy, FTIR, XRD, and EDX analyses. Results FTIR analysis of Polycladia crinita extract showed several sharp absorption peaks at 3435.2, 1423.5, and 876.4 cm−1 which represent O–H, C=O and C=C groups. Moreover, the most frequent functional groups identified in P. crinita aqueous extract that are responsible for producing SeNPs are the –NH2–, –C=O–, and –SH– groups. The EDX spectrum analysis revealed that the high percentages of Se and O, 1.09 ± 0.13 and 36.62 ± 0.60%, respectively, confirmed the formation of SeNPs. The percentages of inhibition of the edema in pretreated groups with doses of 25 and 50 mg/kg, i.p., of PCSeNPs were 62.78% and 77.24%, respectively. Furthermore, the pretreated groups with 25, 50 mg/kg of P. crinita extract displayed a substantial decrease in the MDA levels (P < 0.00, 26.9%, and 51.68% decrease, respectively), indicating potent antioxidant effect. Additionally, the pretreated groups with PCSeNPs significantly suppressed the MDA levels (P < 0.00, 54.77%, and 65.08% decreases, respectively). The results of immune-histochemical staining revealed moderate COX-2 and Il-1β expressions with scores 2 and 1 in rats pre-treated with 25 and 50 mg/kg of free extract, respectively. Additionally, the rats pre-treated with different doses of PCSeNPs demonstrated weak COX-2 and Il-1β expressions with score 1 (25 mg/kg) and negative expression with score 0 (50 mg/kg). Both antioxidant and anti-inflammatory effects were dose-dependent. Conclusions These distinguishing features imply that this unique alga is a promising anti-inflammatory agent. Further studies are required to investigate its main active ingredients and possible side effects.