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DOAJ Open Access 2026
In Vitro Evaluation of the Effect of Microabrasion and Resin Infiltration Materials on Enamel Microhardness and Penetration Depth

Elif Ercan Devrimci, İdil Gönüllü, Hande Kemaloğlu et al.

<b>Background:</b> This in vitro study aimed to evaluate the effect of microabrasion as a surface pretreatment and to compare an experimental resin infiltrant with a commercially available system (ICON) in terms of enamel surface microhardness recovery and resin penetration depth in artificially demineralized enamel lesions. <b>Methods:</b> Forty-eight caries-free human third molars were prepared to obtain standardized enamel specimens, and artificial enamel lesions were created using a pH-cycling model. Specimens were randomly allocated into four groups (<i>n</i> = 12): experimental resin with microabrasion, experimental resin without microabrasion, ICON resin with microabrasion, and ICON resin without microabrasion. When indicated, microabrasion was performed using a 6.6% hydrochloric acid paste for a total application time of 30 s, followed by standard hydrochloric acid etching as part of the infiltration protocol. Enamel surface microhardness was measured at baseline, after demineralization, and after resin infiltration. Resin penetration depth was assessed using confocal laser scanning microscopy, with six specimens per group (<i>n</i> = 6). Data were analyzed using repeated-measures mixed-effects models and one-way ANOVA (<i>p</i> < 0.05). <b>Results:</b> Resin infiltration resulted in a partial recovery of enamel surface microhardness following demineralization; however, baseline hardness values were not fully restored, and no statistically significant differences were observed among the study groups (<i>p</i> > 0.05). These findings indicate surface stabilization rather than complete mechanical or mineral restoration. The ICON resin demonstrated significantly greater penetration depth than the experimental resin. In both resin systems, microabrasion significantly increased penetration depth. <b>Conclusions:</b> Within the limitations of this in vitro study, resin infiltration primarily contributed to the stabilization of demineralized enamel surfaces rather than true remineralization or full mechanical recovery. Although microabrasion enhanced resin penetration depth, this effect should be interpreted with caution due to the potential for cumulative enamel loss. From a clinical perspective, these findings support the selective use of microabrasion to enhance resin infiltration in early enamel lesions with pronounced surface barriers, while emphasizing the need to balance penetration benefits against enamel preservation.

Biotechnology, Medicine (General)
DOAJ Open Access 2025
Power-Driven Electroporation Is Predictive of Treatment Outcomes in a Conductivity-Independent Manner

Edward J. Jacobs, Julio P. Arroyo, Manali Powar et al.

Objective: This study characterizes the effects of external conductivity on electroporation to develop methods to overcome potential patient-to-patient variability. Impact Statement: We demonstrate that constant power pulsed electric fields (PEFs) achieve consistent treatment outcomes despite variations in conductivity, thereby improving the predictability and efficacy of electroporation-based therapies. Introduction: Electropermeabilization-based therapies typically deliver static voltages between electrodes to induce cell permeabilization. However, tissue conductivity variations introduce uncertainty in treatment outcomes, as the tissue-specific electric field thresholds that induce electroporation also depend on the extracellular conductivity. Methods: Cell-laden hydrogels were fabricated with varying extracellular conductivities and treated with constant voltage PEFs. The voltages and currents were recorded to calculate the applied powers, and the reversible and irreversible electroporation thresholds were quantified using cell-impermeant and viability assays. Homogeneous and heterogeneous multi-tissue finite element models were employed to simulate the impact of tumor conductivity variability on the outcomes of reversible and irreversible electroporation for constant applied voltage, current, and power PEFs. Additionally, an in vivo murine pancreatic tumor model assessed the correlation between PEF delivery and treatment efficacy. Results: The In vitro experiments revealed that the electric field and current density thresholds were conductivity dependent, whereas the power density thresholds remained stable under variable conductivities. Computational modeling indicated that constant power PEFs best predicted tumor coverage in both homogeneous and heterogeneous multi-tissue models. Similarly, the in vivo tumor responses were also better predicted by applied power rather than voltage or current alone. Conclusions: Applying constant power PEFs enables consistent electroporation outcomes despite variations in conductivity.

Medical technology, Biotechnology
DOAJ Open Access 2025
Metabolic capabilities of key rumen microbiota drive methane emissions in cattle

Wanxin Lai, Antton Alberdi, Andy Leu et al.

ABSTRACT The rumen microbiome plays a critical role in determining feed conversion and methane emissions in cattle, with significant implications for both agricultural productivity and environmental sustainability. In this study, we applied a hierarchical joint species distribution model to predict directional associations between biotic factors and abundances of microbial populations determined via metagenome-assembled genomes (MAGs). Our analysis revealed distinct microbial differences, including 191 MAGs significantly more abundant in animals with a higher methane yield (above 24 g/kg dry matter intake [DMI]; high-emission cattle), and 220 MAGs more abundant in low-emission cattle. Interestingly, the microbiome community of the low-methane-emission rumen exhibited higher metabolic capacity but with lower functional redundancy compared to that of high-methane-emission cattle. Our findings also suggest that microbiomes associated with low methane yields are prevalent in specific functionalities such as active fiber hydrolysis and succinate production, which may enhance their contributions to feed conversion in the host animal. This study provides an alternate genome-centric means to investigate the microbial ecology of the rumen and identify microbial and metabolic intervention targets that aim to reduce greenhouse gas emissions in livestock production systems.IMPORTANCERuminant livestock are major contributors to global methane emissions, largely through microbial fermentation in the rumen. Understanding how microbial communities vary between high- and low-methane-emitting animals is critical for identifying mitigation strategies. This study leverages a genome-centric approach to link microbial metabolic traits to methane output in cattle. By reconstructing and functionally characterizing hundreds of microbial genomes, we observe that a low-methane-emission rumen harbors well-balanced, “streamlined” microbial communities characterized by high metabolic capacity and minimal metabolic overlap across populations (low functional redundancy). Our results demonstrate the utility of genome-level functional profiling in uncovering microbial community traits tied to climate-relevant phenotypes.

DOAJ Open Access 2025
Combination of the LPS/TLR4 Pathway and Fecal Metabolomics Analysis Reveals the Chronic Inflammatory Mechanism of Early Atherosclerosis in Tibetan Miniature Pigs

Qinqin Yang, Songtao Xu, Yueqin Cai et al.

Abstract. Objective:. This study aimed to elucidate the effect of the lipopolysaccharides/toll-like receptor 4 (LPS/TLR4) pathway on early atherosclerosis (AS) development and its associated changes in fecal metabolites, thereby providing an experimental foundation for strategies to prevent and treat early AS. Methods:. Twelve Tibetan miniature pigs aged 4–5 months were divided into normal control (NC) group and AS group (6 pigs in each). The group assignment was primarily based on body weight; Secondary criteria, including glucose, lipid profiles, and inflammatory indices, were considered to ensure balanced baseline characteristics between the 2 groups (all P > 0.05). AS group received a high-fat diet for 16 weeks to establish an AS model, while the NC group received a normal diet. Subsequently, serum levels of lipids and various inflammation and oxidative stress markers were measured. Pathological changes in the aorta and colon tissue, LPS/TLR4 pathway-associated protein expressions in the aorta, as well as occludin and zonula occludens-1 in the colon were also assessed. Proton nuclear magnetic resonance spectra technology was employed for the metabolomic analysis of fecal extracts. Results:. The lipid metabolism was disrupted in AS group, with significantly higher total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels ((12.24 ± 5.24) mmol/L vs. (1.86 ± 0.27) mmol/L, P = 0.004,6; (2.39 ± 0.50) mmol/L vs. (0.83 ± 0.07) mmol/L, P = 0.000,5; (6.94 ± 2.87) mmol/L vs. (0.77 ± 0.18) mmol/L, P = 0.003,3), as compared to that in NC group. Serum factors, including LPS, tumor necrosis factor-α, and malondialdehyde levels of AS group were significantly higher than that of NC group ((1,230.00 ± 192.70) EU/L vs. (695.70 ± 213.70) EU/L), P = 0.001,1; (424.20 ± 176.90) ng/L vs. (51.20 ± 26.61) ng/L, P = 0.023,5; (3.60 ± 0.77) nmol/mL vs. (2.62 ± 0.21) nmol/mL, P = 0.025,4). Pathological evaluations revealed prominent lipid deposition area in the aortic arch, thoracic aorta, and abdominal aorta of the AS group compared with that of the NC group (4.17% ± 2.30% vs. 0, P = 0.006,7; 6.23% ± 2.95% vs. 0, P = 0.003,6; 3.78% ± 2.18% vs. 0, P = 0.008,1). TLR4, nuclear factor kappa-B p65, and tumor necrosis factor-α expression in the aorta tissue of the AS group were upregulated, whereas occludin and zonula occludens-1 expression in colon tissues was downregulated. Additionally, metabolomics identified significant differences in 21 metabolites in the feces of the AS group compared to the NC group, with further analysis linking these differences to amino acid metabolism. Conclusions:. The Tibetan miniature pig model of early AS induced by high-fat intake displayed pronounced chronic inflammation. Preliminary findings suggest that the underlying mechanisms may be associated with the LPS/TLR4 pathway and intestinal metabolic disorders.

Diseases of the circulatory (Cardiovascular) system
DOAJ Open Access 2024
M2 microglia-derived exosome-loaded electroconductive hydrogel for enhancing neurological recovery after spinal cord injury

Pengfei Guan, Lei Fan, Zhaobo Zhu et al.

Abstract Electroconductive hydrogels offer a promising avenue for enhancing the repair efficacy of spinal cord injuries (SCI) by restoring disrupted electrical signals along the spinal cord’s conduction pathway. Nonetheless, the application of hydrogels composed of diverse electroconductive materials has demonstrated limited capacity to mitigate the post-SCI inflammatory response. Recent research has indicated that the transplantation of M2 microglia effectively fosters SCI recovery by attenuating the excessive inflammatory response. Exosomes (Exos), small vesicles discharged by cells carrying similar biological functions to their originating cells, present a compelling alternative to cellular transplantation. This investigation endeavors to exploit M2 microglia-derived exosomes (M2-Exos) successfully isolated and reversibly bonded to electroconductive hydrogels through hydrogen bonding for synergistic promotion of SCI repair to synergistically enhance SCI repair. In vitro experiments substantiated the significant capacity of M2-Exos-laden electroconductive hydrogels to stimulate the growth of neural stem cells and axons in the dorsal root ganglion and modulate microglial M2 polarization. Furthermore, M2-Exos demonstrated a remarkable ability to mitigate the initial inflammatory reaction within the injury site. When combined with the electroconductive hydrogel, M2-Exos worked synergistically to expedite neuronal and axonal regeneration, substantially enhancing the functional recovery of rats afflicted with SCI. These findings underscore the potential of M2-Exos as a valuable reparative factor, amplifying the efficacy of electroconductive hydrogels in their capacity to foster SCI rehabilitation.

Biotechnology, Medical technology
DOAJ Open Access 2024
The use of the species <i>Triticum petropavlovskyi</i> Udacz. et Migusch. to expand the genetic diversity of spring bread wheat

A. E. Druzhin, S. N. Sibikeev, L. V. Andreeva

Background. The species Triticum petropavlovskyi Udacz. et Migusch. has a number of positive traits, but has rarely been used in breeding programs to improve bread wheat cultivars. The introgression of genetic material from this species into the Triticum aestivum L. gene pool will not only expand the genetic diversity of bread wheat with a set of traits valuable for breeders, but also help to analyze the expression of genes from T. petropavlovskyi in a new genetic environment. Materials and methods. Spring bread wheat lines L163 and L164 produced with the participation of bread wheat cv. ‘Voevoda’ and an accession of T. petropavlovskyi were target materials of the study. Conventional methods were applied to perform phenological, phytopathological, genetic, and bread quality evaluations. Statistical processing of the resulting data was carried out using the Agros-2.10 software. Results. L163 and L164 were studied for their morphological and phenological indicators, resistance to pathogens, productivity, and grain quality. Differences in a number of traits between the lines and the recipient cultivar were observed. The introgression of the T. petropavlovskyi genetic material into bread wheat showed both positive and negative effects on some agronomic characteristics. L163 was identified for its resistance to the pathogens of leaf rust and powdery mildew, and tolerance to cereal aphids. It combined high productivity with an increased grain protein content compared to the recipient cultivar. In addition, this line demonstrated good rheological properties of its dough. Conclusion. Merging genetic materials from T. petropavlovskyi and bread wheat cv. ‘Voevoda’ made it possible to produce lines with a set of positive characteristics. The selected line, L163, combined effective resistance to a number of diseases, high grain productivity, and good breadmaking qualities, so it was included in the breeding process.

Biotechnology, Botany
DOAJ Open Access 2024
Targeting mutation sites in the omicron variant of SARS-CoV-2 as potential therapeutic strategy against COVID-19 by antiretroviral drugs

Ochuko L. Erukainure, Aliyu Muhammad, Rahul Ravichandran et al.

The multiple mutation of the spike (S) protein of the Omicron SARS-CoV-2 variant is a major concern, as it has been implicated in the severity of COVID-19 and its complications. These mutations have been attributed to COVID-19-infected immune-compromised individuals, with HIV patients being suspected to top the list. The present study investigated the mutation of the S protein of the omicron variant in comparison to the Delta and Wuhan variants. It also investigated the molecular interactions of antiretroviral drugs (ARVd) vis-à-vis dolutegravir, lamivudine, tenofovir-disoproxilfumarate and lenacapavir with the initiation and termination codons of the mRNAs of the mutated proteins of the omicron variant using computational tools. The complete genome sequences of the respective S proteins for omicron (OM066778.1), Delta (OK091006.1) and Wuhan (NC 045512.2) SARS-CoV-2 variants were retrieved from the National Center for Biotechnology Information (NCBI) database. Evolutionary analysis revealed high trends of mutations in the S protein of the omicron SARS-CoV-2 variant compared to the delta and Wuhan variants coupled with 68 % homology. The sequences of the translation initiation sites (TISs), translation termination sites (TTSs), high mutation region-1 (HMR1) and high region mutation-2 (HMR2) mRNAs were retrieved from the full genome of the omicron variant S protein. Molecular docking analysis revealed strong molecular interactions of ARVd with TISs, TTSs, HMR1 and HMR2 of the S protein mRNA. These results indicate mutations in the S protein of the Omicron SARS-CoV-2 variant compared to the Delta and Wuhan variants. These mutation points may present new therapeutic targets for COVID-19.

Toxicology. Poisons
DOAJ Open Access 2024
Combining 2′-fucosyllactose and galacto-oligosaccharides exerts anti-inflammatory effects and promotes gut health

Sewon Park, Yoonhee Park, Yu-Jin Jeong et al.

ABSTRACT: This study investigated the potential of 2′-fucosyllactose (2′-FL) and galacto-oligosaccharides (GOS) combinations as a novel and cost-effective substitute for human milk oligosaccharides (HMO) in promoting gut health and reducing inflammation. In vitro studies using caco-2 cells showed that 2′-FL and GOS combinations (H1 = GOS:2′-FL ratio of 1.8:1; H2 = GOS:2′-FL ratio of 3.6:1) reduced LPS-induced inflammation by decreasing pro-inflammatory markers, whereas individual treatments had no significant effects. In a mouse model of dextran sulfate sodium (DSS)-induced colitis, combined 2′-FL and GOS supplementation alleviated symptoms, improved gut permeability, and enhanced intestinal structure, with the GH1 group (H1 combo with DSS) being the most effective. 2′-Fucosyllactose and GOS combinations also enhanced short-chain fatty acid production in infant fecal batch fermentation and mouse fecal analysis, with GH1 showing the most promising results. The GH1 supplementation altered gut microbiota in mice with DSS-induced colitis, promoting microbial diversity and a more balanced Firmicutes to Bacteroidota ratio. Infant formula products (IFP) containing 2′-FL and GOS combinations (IFP2 = 174 mg of GOS and 95 mg of 2′-FL per 14 g serving, 1.8:1 ratio; IFP3 = 174 mg of GOS and 48 mg of 2′-FL per 14 g serving, 3.6:1 ratio) demonstrated gastrointestinal protective and anti-inflammatory properties in a co-culture model of caco-2 and THP-1 cells. These findings suggest that 2′-FL and GOS combinations have potential applications in advanced infant formulas and supplements to promote gut health and reduce inflammation.

Dairy processing. Dairy products, Dairying
DOAJ Open Access 2022
Sorafenib-Entrapped, Self-Assembled Pullulan&ndash;Stearic Acid Biopolymer-Derived Drug Delivery System to PLC/PRF/5 Hepatocellular Carcinoma Model

Chirayil TJ, Kumar GSV

Teena Jacob Chirayil,1,2 G S Vinod Kumar1 1Nano Drug Delivery Systems (NDDS), Cancer Biology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala, India; 2Research Scholar, Department of Biotechnology, University of Kerala, Thiruvananthapuram, Kerala, IndiaCorrespondence: G S Vinod Kumar, Tel +91 471 2781217, Email gsvinod@rgcb.res.inPurpose: This study aimed to design a prototypic drug delivery system (DDS) made of an amphiphilic, pullulan (Pull)-derived biodegradable polymer for targeting the asialoglycoprotein receptor (ASGPR) overexpressed in HCC. Stearic acid (SA) was conjugated to increase the hydrophobicity of pullulan (Pull-SA).Methods: Pullulan (Pull) was linked to stearic acid (SA) after functional group modifications via EDC/NHS chemistry and characterized. Sorafenib tosylate (SRFT) was entrapped in pullulan–stearic acid nanoparticles (Pull-SA-SRFT) and its particle size, zeta potential, entrapment efficiency (EE), loading capacity (LC), and release efficiency was measured. The competence of Pull-SA-SRFT over SRFT in vitro was assessed using the ASGPR over-expressing PLC/PRF/5 hepatocellular carcinoma (HCC) cell line. This was done by studying cytotoxicity by MTT assay and chromosome condensation assay, early apoptosis by annexin-Pi staining, and late apoptosis by live–dead assay. The cellular uptake study was performed by incorporating coumarin-6 (C6) fluorophore in place of SRFT in Pull-SA conjugates. A biodistribution study was conducted in Swiss-albino mice to assess the biocompatibility and targeting properties of SRFT and Pull-SA-SRFT to the liver and other organs at 1, 6, 24, and 48 h.Results: The characterization studies of the copolymer confirmed the successful conjugation of Pull-SA. The self-assembled amphiphilic nanocarrier could proficiently entrap the hydrophobic drug SRFT to obtain an entrapment efficiency of 95.6% (Pull-SA-SRFT). Characterization of the synthesized nanoparticles exhibited highly desirable nanoparticle characteristics. In vitro, apoptotic studies urged that Pull-SA-SRFT nanoparticle was delivered more efficiently to HCC than SRFT. The cellular uptake study performed, gave propitious results in 4 hrs. The biodistribution study conducted in immunocompetent mice suggested that Pull-SA-SRFT was delivered more than SRFT to the liver when compared to other organs, and that the system was biocompatible.Conclusion: Pull-SA-SRFT is a promisingly safe, biodegradable, cell-specific nanocarrier and a potential candidate to target hydrophobic drugs to HCC.Graphical Abstract: Keywords: pullulan stearic acid nanoparticles, hepatocellular carcinoma, drug delivery system

Medicine (General)
DOAJ Open Access 2022
Reproduction in South American wild canids—A review

Jaqueline Candido de Carvalho, Jaqueline Candido de Carvalho, Fabiana Ferreira Souza et al.

Canids occupy the top of the food chain and are fundamental in sustaining a wild animal/environmental balance. South America, the most biodiverse continent, has 11 species of canids inhabiting diverse biomes, with or without overlapping territories. Although several species are threatened, little is known about their reproductive biology. Remarkably, basic knowledge regarding ejaculate characteristics, sexual behavior, female reproductive cycles, pregnancy and management, and parturition are scarce or absent. These gaps complicate or preclude development of conservation programs. This review compiles the current knowledge of the reproductive biology of South American canids and discusses implications of this scenario.

Veterinary medicine
DOAJ Open Access 2022
Source material for breeding winter bread wheat for grain quality in the north of the Middle Volga Region

I. D. Fadeeva, I. Yu. Ignatieva, A. G. Khakimova et al.

Background. Development of cultivars with high stable yields and high grain quality is the main trend in wheat breeding. The aim of this study was to characterize a set of winter bread wheat accessions from the VIR collection and the working collection of Kazan Scientific Center in terms of their yield, protein content in grain (P, %), and swelling of flour in acetic acid (S, ml), and select the best accessions for the combination of these characters for use in a crossbreeding program.Materials and methods. Twenty-three winter bread wheat accessions were studied for the abovementioned characters in the north of the Middle Volga Region using conventional techniques. The study lasted three years (2016–2019).Results and conclusion. The yield of the accessions varied across the years of studies; however, none of them surpassed the reference cv. ‘Kazanskaya 560’. The values of protein content in grain were medium or high. The following accessions had high and stable levels of protein content in grain (15.1–16.1%): ‘TAW 42971/80’ (k-58363, Germany); ‘Lutescens 471 N8’ (Kazakhstan); ‘Rita’ (k-58057), ‘Scotty’ (k-59322) and ‘Nelson’ (all from the U.S.); ‘Moskovskaya 39’ (k-65160, Russia); ‘Bilotserkivchanka’ (k-64330) and ‘Barkan’ (k-64495) (both from Ukraine). Flour swelling power in acetic acid did not fall below 50 ml, attesting to the formation of high-quality grain. This was also confirmed by the protein quality index determined by the S : P ratio, which ranged from 3.6 to 4.7. Sources with high-quality protein were selected from the tested accessions for use in breeding: ‘CDC Clair’ (k-64168, Canada), ‘Lutescens 471 Н8’ (Kazakhstan), ‘Moskovskaya 39’ (Russia), ‘Barkan’ (Ukraine), and ‘Favorytka’ (k-64337, Ukraine).

Biotechnology, Botany
DOAJ Open Access 2021
Self-synergistic effect of Prussian blue nanoparticles for cancer therapy: driving photothermal therapy and reducing hyperthermia-induced side effects

Xue Xie, Wei Gao, Junnian Hao et al.

Abstract Background Photothermal therapy (PTT), involving application of localized hyperthermia to kill cancer cells, has attracted wide attention in cancer therapy. The production of reactive oxygen species (ROS) during PTT may cause irreversible damage to healthy tissues around the tumor. Simultaneously, hyperthermia can stimulate inflammatory response, thus promoting tumor recurrence and metastasis. Therefore, it is of paramount importance to reduce the undesired side effects for further development of PTT. Results Using a hydrothermal method, spherical Prussian blue nanoparticles (PBs) with uniform size were prepared. The PBs exhibited good dispersion and stability in saline with an average hydrodynamic size of 110 nm. The prepared PBs had a high photothermal conversion efficiency and photothermal stability. The PBs showed intrinsic ROS scavenging properties in vitro. Antioxidant and anti-inflammatory effects of PBs were also observed in vivo. Assessment of toxicity and endoplasmic reticulum stress-inducing ability showed that PBs did not induce an inflammatory response. Tissues of major organs of mice stained with hematoxylin–eosin showed no significant damage, indicating good biocompatibility and safety of PBs. Conclusion The designed single-component PBs with intrinsic ROS scavenging and anti-inflammatory properties could avoid inflammatory response and heat stress-induced ROS during PTT. Thus, further research on PBs is worthwhile to achieve their clinical translation and promote the development of PTT.

Biotechnology, Medical technology
DOAJ Open Access 2020
Engineering the Yeast Yarrowia lipolytica for Production of Polylactic Acid Homopolymer

Sophie Lajus, Simon Dusséaux, Jonathan Verbeke et al.

Polylactic acid is a plastic polymer widely used in different applications from printing filaments for 3D printer to mulching films in agriculture, packaging materials, etc. Here, we report the production of poly-D-lactic acid (PDLA) in an engineered yeast strain of Yarrowia lipolytica. Firstly, the pathway for lactic acid consumption in this yeast was identified and interrupted. Then, the heterologous pathway for PDLA production, which contains a propionyl-CoA transferase (PCT) converting lactic acid into lactyl-CoA, and an evolved polyhydroxyalkanoic acid (PHA) synthase polymerizing lactyl-CoA, was introduced into the engineered strain. Among the different PCT proteins that were expressed in Y. lipolytica, the Clostridium propionicum PCT exhibited the highest efficiency in conversion of D-lactic acid to D-lactyl-CoA. We further evaluated the lactyl-CoA and PDLA productions by expressing this PCT and a variant of Pseudomonas aeruginosa PHA synthase at different subcellular localizations. The best PDLA production was obtained by expressing the PCT in the cytosol and the variant of PHA synthase in peroxisome. PDLA homopolymer accumulation in the cell reached 26 mg/g-DCW, and the molecular weights of the polymer (Mw = 50.5 × 103 g/mol and Mn = 12.5 × 103 g/mol) were among the highest reported for an in vivo production.

DOAJ Open Access 2020
A lab‐on‐a‐chip model of glaucoma

Fatemeh Nafian, Babak Kamali Doust Azad, Shahin Yazdani et al.

Abstract Aims We developed a glaucoma‐on‐a‐chip model to evaluate the viability of retinal ganglion cells (RGCs) against high pressure and the potential effect of neuroprotection. Methods A three‐layered chip consisting of interconnecting microchannels and culture wells was designed and fabricated from poly‐methyl methacrylate sheets. The bottom surface of the wells was modified by air plasma and coated with different membranes to provide a suitable extracellular microenvironment. RGCs were purified from postnatal Wistar rats by magnetic assisted cell sorting up to 70% and characterized by flow cytometry and immunocytochemistry. The cultured RGCs were exposed to normal (15 mmHg) or elevated pressure (33 mmHg) for 6, 12, 24, 36, and 48 hr, with and without adding brain‐derived neurotrophic factor (BDNF) or a novel BDNF mimetic (RNYK). Results Multiple inlet ports allow culture media and gas into the wells under elevated hydrostatic pressure. PDL/laminin formed the best supporting membrane. RGC survival rates were 85%, 78%, 70%, 67%, and 61% under normal pressure versus 40%, 22%, 18%, 12%, and 10% under high pressure at 6, 12, 24, 36, and 48 hr, respectively. BDNF and RNYK separately reduced RGC death rates about twofold under both normal and elevated pressures. Conclusion This model recapitulated the effects of elevated pressure over relatively short time periods and demonstrated the neuroprotective effects of BDNF and RNYK.

Neurosciences. Biological psychiatry. Neuropsychiatry
DOAJ Open Access 2019
The initiation of puberty in Atlantic salmon brings about large changes in testicular gene expression that are modulated by the energy status

Diego Crespo, Jan Bogerd, Elisabeth Sambroni et al.

Abstract Background When puberty starts before males reach harvest size, animal welfare and sustainability issues occur in Atlantic salmon (Salmo salar) aquaculture. Hallmarks of male puberty are an increased proliferation activity in the testis and elevated androgen production. Examining transcriptional changes in salmon testis during the transition from immature to maturing testes may help understanding the regulation of puberty, potentially leading to procedures to modulate its start. Since differences in body weight influence, via unknown mechanisms, the chances for entering puberty, we used two feed rations to create body weight differences. Results Maturing testes were characterized by an elevated proliferation activity of Sertoli cells and of single undifferentiated spermatogonia. Pituitary gene expression data suggest increased Gnrh receptor and gonadotropin gene expression, potentially responsible for the elevated circulating androgen levels in maturing fish. Transcriptional changes in maturing testes included a broad variety of signaling systems (e.g. Tgfβ, Wnt, insulin/Igf, nuclear receptors), but also, activation of metabolic pathways such as anaerobic metabolism and protection against ROS. Feed restriction lowered the incidence of puberty. In males maturing despite feed restriction, plasma androgen levels were higher than in maturing fish receiving the full ration. A group of 449 genes that were up-regulated in maturing fully fed fish, was up-regulated more prominently in testis from fish maturing under caloric restriction. Moreover, 421 genes were specifically up-regulated in testes from fish maturing under caloric restriction, including carbon metabolism genes, a pathway relevant for nucleotide biosynthesis and for placing epigenetic marks. Conclusions Undifferentiated spermatogonia and Sertoli cell populations increased at the beginning of puberty, which was associated with the up-regulation of metabolic pathways (e.g. anaerobic and ROS pathways) known from other stem cell systems. The higher androgen levels in males maturing under caloric restriction may be responsible for the stronger up-regulation of a common set of (449) maturation-associated genes, and the specific up-regulation of another set of (421) genes. The latter opened regulatory and/or metabolic options for initiating puberty despite feed restriction. As a means to reduce the incidence of male puberty in salmon, however, caloric restriction seems unsuitable.

Biotechnology, Genetics
DOAJ Open Access 2017
Regulation of antimicrobial activity and xenocoumacins biosynthesis by pH in Xenorhabdus nematophila

Shuqi Guo, Shujing Zhang, Xiangling Fang et al.

Abstract Background Xenocoumacin 1 (Xcn1) and Xenocoumacin 2 (Xcn2) are the main antimicrobial compounds produced by Xenorhabdus nematophila. Culture conditions, including pH, had remarkably distinct effects on the antimicrobial activity of X. nematophila. However, the regulatory mechanism of pH on the antimicrobial activity and antibiotic production of this bacterium is still lacking. Results With the increase of initial pH, the antimicrobial activity of X. nematophila YL001 was improved. The levels of Xcn1 and nematophin at pH 8.5 were significantly (P < 0.05) higher than that at pH 5.5 and 7.0. In addition, the expression of xcnA-L, which are responsible for the production of Xcn1 was increased and the expression of xcnMN, which are required for the conversion of Xcn1 to Xcn2 was reduced at pH 8.5. Also, the expression of ompR and cpxR were decreased at pH 8.5. Conclusion The alkaline pH environment was found to be beneficial for the production of Xcn1 and nematophin, which in turn led to high antimicrobial activity of X. nematophila at pH 8.5.

DOAJ Open Access 2015
Genome-wide analysis of potential cross-reactive endogenous allergens in rice (Oryza sativa L.)

Fang Chao Zhu, Rui Zong Jia, Lin Xu et al.

The proteins in the food are the source of common allergic components to certain patients. Current lists of plant endogenous allergens were based on the medical/clinical reports as well as laboratory results. Plant genome sequences made it possible to predict and characterize the genome-wide of putative endogenous allergens in rice (Oryza sativa L.). In this work, we identified and characterized 122 candidate rice allergens including the 22 allergens in present databases. Conserved domain analysis also revealed 37 domains among rice allergens including one novel domain (histidine kinase-, DNA gyrase B-, and HSP90-like ATPase, PF13589) adding to the allergen protein database. Phylogenetic analysis of the allergens revealed the diversity among the Prolamin superfamily and DnaK protein family, respectively. Additionally, some allergens proteins clustered on the rice chromosome might suggest the molecular function during the evolution.

Toxicology. Poisons

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