Fish meal grades SL1 and SL2 from Sardine (Sardinella longiceps) and NJ from Pink Perch (Nemipterus japonicas) were evaluated as a sole source of carbon and nitrogen in the medium for alkaline protease production by Bacillus pumilus MTCC 7514. The analysis of the fish meal suggests that the carbon and nitrogen contents in fish meal are sufficient to justify its choice as replacement for other nutrients. Protease production increased significantly (4,914 U/ml) in medium containing only fish meal, compared with the basal medium (2,646 U/ml). However, the elimination of inorganic salts from media reduced the protease productivity. In addition, all the three grades of fish meal yielded almost the same amounts of protease when employed as the sole source of carbon and nitrogen. Nevertheless, the best results were observed in fish meal SL1 medium. Furthermore, protease production was enhanced to 6,966 U/ml and 7,047 U/ml on scaling up from flask (4,914 U/ml) to 3.7 and 20 L fermenters, respectively, using fish meal (10 g/l). Similarly, the corresponding improvement in productivities over flask (102.38 U/ml/h) was 193.5 and 195.75 U/ml/h in 3.7 and 20 L fermenters, respectively. The crude protease was found to have dehairing ability in leather processing, which is bound to have great environmental benefits.

Human SL1 is a general transcription initiation factor (GTF) essential for RNA polymerase I to start rRNA synthesis at class I promoters. It is comprised of the TATA box-binding protein (TBP) and three TBP-associated factors (TAF(I)48, TAF(I)63 and TAF(I)110). We have determined that the human genes TAF1A, TAF1B and TAF1C, encoding these three TAF(I) polypeptides, are localized at lq42, 2p25 and 16q24, respectively. All three genes are present as single copies in the human genome and map to different chromosomes, as shown by somatic cell hybrid panel and radiation hybrid panel analysis and FISH. Two of these genes, TAF1C and TAF1B, are transcribed into multiple RNAs, as determined through Northern analysis of mRNA from various human organs and cell lines. If translated into different polypeptides, this could result in production of variant isoforms of SL1 with different activation potentials.

Hepatocyte growth factor (HGF)/c-met pathway activation has been implicated in the pathogenesis of multiple myeloma (MM), and blocking this pathway has been considered a rational therapeutic strategy for treating MM. Aptamers are single-stranded nucleic acid molecules that fold into complex 3D structures and bind to a variety of targets. Recently, it was reported that DNA aptamer SL1 exhibited high specificity and affinity for c-met and inhibited HGF/c-met signaling in SNU-5 cells. However, as the first c-met-targeted DNA aptamer to be identified, application of SL1 to myeloma treatment requires further investigation. Here, we explore the potential application of SL1 in MM. Our results indicated that c-met expression is gradually increased in MM patients and contributes to poor outcomes. SL1 selectively bound to c-met-positive MM cells but not to normal B cells and suppressed the growth, migration and adhesion of MM cells in vitro in a co-culture model performed with HS5 cells, wherein SL1 inhibited HGF-induced activation of c-met signaling. In vivo and ex vivo fluorescence imaging showed that SL1 accumulated in the c-met positive tumour areas. In addition, SL1 was active against CD138+ primary MM cells and displayed a synergistic inhibition effect with bortezomib. Collectively, our data suggested that SL1 could be beneficial as a c-met targeted antagonist in MM.

Altered expression of NEAT1, the architectural long non-coding RNA (lncRNA) of nuclear paraspeckles, has been reported during tumorigenesis, as well as under various cellular stress conditions. Here we report that the depletion of NEAT1 lncRNA alleviates nucleolar stress during RNAP I inhibition through releasing sequestered P54nrb and PSF to facilitate the IRES-dependent translation of c-Myc. RNAP I inhibitor CX5461 disrupts the SL1-rDNA interaction and induces nucleolar disruption, demonstrated by the accumulation of fibrillarin-containing nucleoplasmic foci and nucleolar clearance of ribosomal proteins in HeLa cells. Antisense oligonucleotide-mediated depletion of NEAT1 lncRNA significantly attenuated the RNAP I inhibition and its related nucleolar disruption. Interestingly, induction in the levels of c-Myc protein was observed in NEAT1-depeleted cells under RNAP I inhibition. NEAT1-associated paraspeckle proteins P54nrb and PSF have been reported as positive regulators of c-Myc translation through interaction with c-Myc IRES. Indeed, an increased association of P54nrb and PSF with c-Myc mRNA was observed in NEAT1-depleted cells. Moreover, apoptosis was observed in HeLa cells depleted of P54nrb and PSF, further confirming the positive involvement of P54nrb and PSF in cell proliferation. Together, our results suggest that NEAT1 depletion rescues CX5461-induced nucleolar stress through facilitating c-Myc translation by relocating P54nrb/PSF from nuclear paraspeckles to c-Myc mRNAs.

OBJECTIVE

Titanium dioxide (TiO2), a photocatalyst, is known to decompose various organic compounds under ultraviolet (UV) illumination by generating various radicals, which is useful for killing bacteria. The purpose of the present study was to evaluate the photocatalytic bactericidal effects of variously treated titanium surfaces on Streptococcus sanguinis SL1.

METHODS

Specimens were fabricated from grade 4 commercially pure titanium, 10 mm in diameter and 2 mm in thickness. Three different surfaces were prepared: anodized (AO) at 270 V, heat-treated (HT), and machined (MA). Surface analysis was performed using confocal laser scanning microscope, scanning electron microscopy, and thin-film x-ray diffractometry. The antibacterial activities were assessed by comparing adhesion and survival rates of S sanguinis on various surfaces under UV illumination.

RESULTS

The AO surface was rougher than the HT and MA surfaces. The AO surface showed TiO2 peaks of anatase structure, while the HT surface showed TiO2 peaks of rutile structure in x-ray diffractometry. HT and AO surfaces showed significantly decreased bacterial adhesion under UV illumination (AO and HT>> control, AO>> MA). In addition, bacterial adhesion decreased more significantly with extended UV illumination time. With respect to survival rates of bacteria, AO and HT showed a significant reduction over time compared to MA. The photocatalytic bactericidal effect was maximal on the AO titanium, followed by HT and MA.

CONCLUSIONS

The photo-induced bactericidal efficacy of TiO2 films is dependent on their surface characteristics.

The let-23 gene in the nematode Caenorhabditis elegans encodes a receptor tyrosine kinase and is necessary for the induction of a vulva, survival past the L1 stage, hermaphrodite fertility and for male spicule development. We sequenced the entire let-23 genomic region of over 12 kb. The 5' end of the let-23 mRNA was mapped by sequencing polymerase chain reaction products, and two mRNAs were found which had alternative exons and were probably initiated at different sites. One transcript was trans-spliced to SL1. Expression of either cDNA rescued a let-23 vulvaless mutation in germline transformation. These results suggest that the let-23 gene encodes two proteins of 1323 or 1335 amino acid residues. We prepared various 5' deletion constructs of the let-23 gene, and examined their rescue activities for a let-23 lethal or vulvaless mutation. The results revealed that two regions were required for let-23 expression, one for larval survival and the other for vulva formation. We also cloned and analyzed a let-23 homologue from Caenorhabditis vulgaris. It can encode two proteins of 77% amino acid residue identity with the Let-23 proteins. The 12 kb fragment carrying the C. vulgaris gene rescued the let-23 vulvaless mutation in C. elegans. Seventeen sequences highly conserved between the two species were identified in the 5' upstream region or within an intron. Three of these sequences are contained in the two regions required for let-23 expression, suggesting that they are cis-acting elements for let-23 expression.

Structured lipids (SLs) with high palmitic acid content at the sn-2 position enriched with arachidonic acid (ARA) and docosahexaenoic acid (DHA) were produced using extra virgin olive oil, tripalmitin, ARA and DHA single cell oil free fatty acids. Four types of SLs were synthesized using immobilized lipases, Novozym 435 and Lipozyme TL IM, based on one-stage (one-pot) and two-stage (sequential) syntheses. The SLs were characterized for fatty acid profile, triacylglycerol (TAG) molecular species, melting and crystallization profiles, tocopherols, and phenolic compounds. All the SLs had >50 mol % palmitic acid at the sn-2 position. The predominant TAGs in all SLs were PPO and OPO. The total tocopherol content of SL1-1, SL1-2, SL2-1, and SL2-2 were 70.46, 68.79, 79.64, and 79.31 μg/g, respectively. SL1-2 had the highest melting completion (42.0 °C) and crystallization onset (27.6 °C) temperatures. All the SLs produced in this study may be suitable as infant formula fat analogues.

The hypocholesterolemic effects of two low calorie structured lipids (SL1 and SL2) containing essential fatty acids, prepared by lipase catalysed interesterification of ethyl behenate respectively with sunflower and soybean oils were studied in rats and rabbits. The feeding experiment conducted on rats as well as rabbits, fed on normal and atherogenic diet containing 10% of SL1 and SL2 (experimental) and sunflower oil (control) indicated no adverse effects on growth and food intake. However, the structured lipids beneficially lowered serum and liver lipids, particularly cholesterol, LDL cholesterol, triglycerides and also maintains the essential fatty acid status in serum and liver. The lipid deposition observed in the arteries of rabbits fed on atherogenic diets was significantly reduced when structured lipids were included in the diet. These observations coincided with reduced levels of serum cholesterol particularly LDL cholesterol observed in experimental groups. Therefore the structured lipids, designed to have low calorific value also beneficially lower serum lipids and lipid deposition in animals fed on atherogenic diets.

The St. mutans strains studied were: HS6 "a"; BHT "b"; IB "c"; B13 "d"; LM7 "e"; OMZ175 "f"; OMZ65 "g"; SL1 "SL"; 6715 "d/g". Immune sera and antigen preparation as well as antigen-antibody reactions were performed using the above-mentioned strains. The immune sera were obtained following Knox technique, including formolated immunogen with and without adjuvant. Linzer method was followed for rabbit immunization. The antigen extract were prepared according to Rantz and Randall method. The antigen-antibody reaction were carried out by microimmunodiffusion (MID) Ouchterlony technique and by counterimmunoelectrophoresis (CIE) according to De Torres method. A good correlation was found in the antigen-antibody reactions for the serotypes studied. MID and CIE revealed some cross-reactions, as already described by many investigators. The results obtained are compatible with St. mutans antigenic instability. The eight serotypes from St. mutans could possibly be reduced to four related groups: Group 1: serotypes "a-d-g-SL"; Group 2: serotype "e-f"; Group 3: serotype "c" (uncertain position: it can be related with group 1 or 2); Group 4: serotype "b". CIE is a convenient technique to be incorporated for immunological determination.

Two galactose-binding lectins, SL1 and SL2, were isolated from human serum by two-step affinity chromatography on sorbents with immobilized disaccharides Gal beta 1-3GlcNAc beta (Lec) and Fuc alpha 1-2Gal beta (Hdi). The purification degree of the SL1 and SL2 preparations was 4000-6000 times and yields were 6.9 and 4.7 micrograms/ml of serum, respectively. Electrophoresis showed that both lectins are oligomers with molecular masses of about 440 kDa, which are composed of ca. 67 kDa subunits. The carbohydrate specificity of the lectins was assayed by hemagglutination inhibition using mono- and oligosaccharides. Both lectins showed specificity for Gal and GalNAc residues but differed in the interactions with oligosaccharides. In particular, SL1 showed maximum affinity for disaccharide Gal beta 1-3GalNAc beta (in the form of 4-nitrophenyl glycoside), 6'-sialyllactose, and disaccharide residues Fuc alpha 1-3Gal beta and Gal alpha 1-3Gal beta, whereas SL2 was specific for GalNAc alpha residue and its derivatives as well as for disaccharide Hdi.

Galectins are a family of soluble beta-galactoside-binding lectins distributed in both vertebrates and invertebrates and, more recently, found also in fungus. The 32-kDa galectin isolated from the nematode Caenorhabditis elegans (Hirabayashi, J., Satoh, M., and Kasai, K. (1992) J. Biol. Chem. 267, 15485-15490) was the first "tandem repeat-type" galectin, containing two homologous carbohydrate-binding sites. Here, we report the structure of the nematode 32-kDa galectin gene. Physical mapping by yeast artificial chromosome polytene filter hybridization revealed that the 32-kDa galectin gene is located on chromosome II. Analysis of the transcript (1.4 kilobases) showed the presence at its 5'-end of a 22-nucleotide trans-spliced leader sequence (SL1). The entire genomic structure spanning >5 kilobase pairs (kbp), including the 5'-noncoding region, two intervening sequences (introns 1 and 2), and the 3'-noncoding region, was completely determined by the combination of genomic polymerase chain reaction and conventional colony hybridization. Intron 1 was relatively long (2.4 kbp) and was found to be inserted after the ninth codon (TAC) from the initiation codon. This position proved to be almost homologous to the conserved first intron insertion position in the vertebrate galectin genes (i. e. genes of mammalian galectin-1, -2, and -3 and chick 14-kDa galectin). On the other hand, intron 2 was much shorter (0.6 kbp), and it was inserted into the central region of the second carbohydrate-binding site. Although such an insertion pattern has never been observed in the vertebrate galectin genes, it seems to be common in C. elegans tandem repeat-type galectin genes, as predicted by the C. elegans genome project (Coulson, A., and the C. elegans Genome Consortium (1996) Biochem. Soc. Trans. 24, 289-291). Based on extensive sequence comparison, the origin and molecular evolution of the tandem repeat-type galectins are discussed.

A smooth muscle contractile material was separated from crude venom of the scorpion Heterometrus bengalensis (found in Eastern India) by solvent extraction, gel filtration and thin layer chromatography. Smooth muscle contractile material could be extracted, in descending order of efficiency, with methanol, butanol, ethanol and acetone. The contractile material separated by gel filtration (Sephadex G-25) when further extracted, using the Folch procedure, showed a single spot in thin layer chromatography with one solvent system. Rechromatography of an eluate from this spot with another solvent system resolved it into three spots (SL1, SL2 and SL3, the mixture being designated as Substance L) which could be visualized either with iodine vapour, ninhydrin or molybdenum reagent. Eluates from the three spots contracted guinea-pig ileum which had been pretreated with antagonists of ACh, histamine, 5-HT and prostaglandins. Substance L and its fractions (SL1, SL2 and SL3) contain inorganic phosphorus, amino nitrogen and amino sugar, which point to the likelihood of their being glycophosphatides.

We have used RNA-seq in Caenorhabditis elegans to produce transcription profiles for seven specific embryonic cell populations from gastrulation to the onset of terminal differentiation. The expression data for these seven cell populations, covering major cell lineages and tissues in the worm, reveal the complex and dynamic changes in gene expression, both spatially and temporally. Also, within genes, start sites and exon usage can be highly differential, producing transcripts that are specific to developmental periods or cell lineages. We have also found evidence of novel exons and introns, as well as differential usage of SL1 and SL2 splice leaders. By combining this data set with the modERN ChIP-seq resource, we are able to support and predict gene regulatory relationships. The detailed information on differences and similarities between gene expression in cell lineages and tissues should be of great value to the community and provides a framework for the investigation of expression in individual cells.

Recently, two-dimensional transition metal dichalcogenide (TMDC) monolayers have attracted much attention owing to their excellent physical properties. In the present study, we systematically investigate the thermoelectric properties of different WS₂-WSe₂ phononic crystals by utilizing first-principles calculations. First, the thermal properties of all phononic crystals with superlattices (SL1 and SL2) and their individual components (WS₂ and WSe₂) are evaluated, in which the lattice thermal conductivities (k_ph) of WS₂ and WSe₂ monolayers present isotropic behaviors, while the values of SL1 and SL2 monolayers reveal weak anisotropic behaviors. It can be observed that the k_ph values of WS₂ and WSe₂ monolayers are larger than those of SL1 and SL2 monolayers, which can be attributed to the decreasing phonon group velocity and phonon lifetime. Moreover, we calculate the electronic band structures of all monolayers, indicating that all monolayers are semiconductors. Afterwards, the electrical conductivities, the Seebeck coefficients, the power factors, the electronic thermal conductivities, and the ZT values at different temperatures are evaluated. The ZT_max values of WS₂, WSe₂, SL1, and SL2 monolayers with p-type doping are 0.43, 0.37, 0.95, and 0.66 at 1000 K. It can be proved that the SL1 monolayer possesses the largest ZT, which is at least two times higher than those of the WS₂ and WSe₂ monolayer. Finally, we build two kinds of phononic crystals with periodic holes (PCH1 and PCH2) and evaluate the thermoelectric properties. It can be observed that the PCH2 structure shows the best thermoelectric performance. The ZT_max values of the PCH2 structure can reach 2.53 and 4.54 with p-type doping along the x and y directions, which are 2.66 and 6.75 times higher than those of the SL1 monolayer. This work provides a new strategy to obtain higher thermoelectric performance and demonstrates the potential applications of phononic crystals in TMDC-based nanoelectronic devices.

Ribosomal RNA (rRNA) is transcribed from rDNA by RNA polymerase I (Pol I) to produce the 45S precursor of the 28S, 5.8S, and 18S rRNA components of the ribosome. Two transcription factors have been defined for Pol I in mammals, the selectivity factor SL1, and the upstream binding transcription factor (UBF), which interacts with the upstream control element to facilitate the assembly of the transcription initiation complex including SL1 and Pol I. In seven unrelated affected individuals, all suffering from developmental regression starting at 2.5-7 years, we identified a heterozygous variant, c.628G>A in UBTF, encoding p.Glu210Lys in UBF, which occurred de novo in all cases. While the levels of UBF, Ser388 phosphorylated UBF, and other Pol I-related components (POLR1E, TAF1A, and TAF1C) remained unchanged in cells of an affected individual, the variant conferred gain of function to UBF, manifesting by markedly increased UBF binding to the rDNA promoter and to the 5'- external transcribed spacer. This was associated with significantly increased 18S expression, and enlarged nucleoli which were reduced in number per cell. The data link neurodegeneration in childhood with altered rDNA chromatin status and rRNA metabolism.

BACKGROUND

Pathogens exert selective pressure which may lead to substantial changes in host immune responses. The human complement receptor type 1 (CR1) is an innate immune recognition glycoprotein that regulates the activation of the complement pathway and removes opsonized immune complexes. CR1 genetic variants in exon 29 have been associated with expression levels, C1q or C3b binding and increased susceptibility to several infectious diseases. Five distinct CR1 nucleotide substitutions determine the Knops blood group phenotypes, namely Kna/b, McCa/b, Sl1/Sl2, Sl4/Sl5 and KCAM+/-.

METHODS

CR1 variants were genotyped by direct sequencing in a cohort of 441 healthy individuals from Brazil, Vietnam, India, Republic of Congo and Ghana.

RESULTS

The distribution of the CR1 alleles, genotypes and haplotypes differed significantly among geographical settings (p≤0.001). CR1 variants rs17047660A/G (McCa/b) and rs17047661A/G (Sl1/Sl2) were exclusively observed to be polymorphic in African populations compared to the groups from Asia and South-America, strongly suggesting that these two SNPs may be subjected to selection. This is further substantiated by a high linkage disequilibrium between the two variants in the Congolese and Ghanaian populations. A total of nine CR1 haplotypes were observed. The CR1*AGAATA haplotype was found more frequently among the Brazilian and Vietnamese study groups; the CR1*AGAATG haplotype was frequent in the Indian and Vietnamese populations, while the CR1*AGAGTG haplotype was frequent among Congolese and Ghanaian individuals.

CONCLUSIONS

The African populations included in this study might have a selective advantage conferred to immune genes involved in pathogen recognition and signaling, possibly contributing to disease susceptibility or resistance.

The bacterium Streptococcus sobrinus causes tooth decay in humans. We present complete circularized genome sequences for four strains of S. sobrinus, type strain SL1, strain NIDR 6715-7 and the related NIDR 6715-15, and strain NCTC 10919. The finished genomes will enable genomic comparisons between S. sobrinus and other cariogenic microbes.

Tea tree [Camellia sinensis (L.) O. Kuntze] is an important leaf (sometimes tender stem)-using commercial plant with many medicinal uses. The development of newly sprouts would directly affect the yield and quality of tea product, especially significant for Pingyang Tezaocha (PYTZ) which takes up a large percent in the early spring tea market. MicroRNA (miRNA), particularly the conserved miRNAs, often position in the center of subtle and complex gene regulatory systems, precisely control the biological processes together with other factors in a spatio-temporal pattern. Here, quality-determined metabolites catechins, theanine and caffeine in PYTZ sprouts including buds (sBud), different development stages of leaves (sL1, sL2) and stems (sS1, sS2) were quantified. A total of 15 miRNA libraries of the same tissue with three repetitions for each were constructed to explore vital miRNAs during the biological processes of development and quality formation. We analyzed the whole miRNA profiles during the sprout development and defined conserved miRNA families in the tea plant. The differentially expressed miRNAs related to the expression profiles buds, leaves, and stems development stages were described. Twenty one miRNAs and eight miRNA-TF pairs that most likely to participate in regulating development, and at least two miRNA-TF-metabolite triplets that participate in both development and quality formation had been filtered. Our results indicated that conserved miRNA act boldly during important biological processes, they are (i) more likely to be linked with morphological function in primary metabolism during sprout development, and (ii) hold an important position in secondary metabolism during quality formation in tea plant, also (iii) coordinate with transcription factors in forming networks of complex multicellular organism regulation.

Spindlin1 (SPIN1), a histone modification reader protein, was enriched in the cell nucleolus and facilitated rRNA expression. However, how SPIN1 localizes to the nucleolus and its functional role in rRNA gene expression remain unresolved. Here, we identified a nucleolar localization signal in the N-terminal region of SPIN1 that is essential for its enrichment and function in the nucleolus. We also discovered that, in addition to its H3K4me3 recognizing activity, the H3R8me2a-recognizing capacity of SPIN1 is also indispensable for stimulating rRNA expression. Chromatin immunoprecipitation results indicated that SPIN1 is required for the association or assembly of selective factor 1 (SL1) complex, probably facilitating the initiation of rDNA transcription through its H3 K4me3-R8me2a reader function.

Cancer cells transcribe RNAs in a characteristic manner in order to maintain their oncogenic potentials. In eukaryotes, RNA is polymerized by three distinct RNA polymerases, RNA polymerase I, II, and III (RNAP1, RNAP2, and RNAP3, respectively). The transcriptional machinery that initiates each transcription reaction has been purified and characterized. Selectivity factor 1 (SL1) is the complex responsible for RNAP1 pre-initiation complex formation. However, whether it plays any role in RNAP2-dependent transcription remains unclear. Our group previously found that SL1 specifically associates with AF4 family proteins. AF4 family proteins form the AEP complex with ENL family proteins and the P-TEFb elongation factor. Similar complexes have been independently characterized by several different laboratories and are often referred to as super elongation complex. The involvement of AEP in RNAP2-dependent transcription indicates that SL1 must play an important role in RNAP2-dependent transcription. To date, this role of SL1 has not been appreciated. In leukemia, AF4 and ENL family genes are frequently rearranged to form chimeric fusion genes with MLL. The resultant MLL fusion genes produce chimeric MLL fusion proteins comprising MLL and AEP components. The MLL portion functions as a targeting module, which specifically binds chromatin containing di-/tri-methylated histone H3 lysine 36 and non-methylated CpGs. This type of chromatin is enriched at the promoters of transcriptionally active genes which allows MLL fusion proteins to selectively bind to transcriptionally-active/CpG-rich gene promoters. The fusion partner portion, which recruits other AEP components and SL1, is responsible for activation of RNAP2-dependent transcription. Consequently, MLL fusion proteins constitutively activate the transcription of previously-transcribed MLL target genes. Structure/function analysis has shown that the ability of MLL fusion proteins to transform hematopoietic progenitors depends on the recruitment of AEP and SL1. Thus, the AEP/SL1-mediated gene activation pathway appears to be the central mechanism of MLL fusion-mediated transcriptional activation. However, the molecular mechanism by which SL1 activates RNAP2-dependent transcription remains largely unclear. This review aims to cover recent discoveries of the mechanism of transcriptional activation by MLL fusion proteins and to introduce novel roles of SL1 in RNAP2-dependent transcription by discussing how the RNAP1 machinery may be involved in RNAP2-dependent gene regulation.

The aim of the study was to compare the effects of 2 prebiotics and 2 synbiotics injected in ovo on productivity parameters, quality, and microstructure of the superficial pectoral muscle in 35-day-old broiler chickens. On day 12 of incubation, 9,000 eggs Ross 308 were randomly divided into 5 experimental groups treated with different bioactives in ovo injected: C, control with physiological saline; PI, with 1.760 mg inulin; PB, with 0.528 mg of commercial prebiotic Bi2tos; SI, with 1.760 mg inulin and 1,000 CFU Lactococcus lactis spp. lactis IBB SL1; SB, with 0.528 mg Bi2tos and 1,000 CFU Lactococcus lactis spp. cremoris IBB SC1. The synbiotic solution contained 20 μl bacterial suspension and 180 μl prebiotic solution. For productive parameters and further tests ten male birds for each experimental group were used. The birds were slaughtered on day 35 of age. At slaughter, samples of the left pectoral muscles were taken and preserved by freezing in liquid nitrogen. The pH and color of the meat were evaluated at 45 min and 24 h post-mortem. Water holding capacity (WHC) was measured and expressed as the percentage of free water in meat. Microscopic specimens were analysed using MultiScan software for the measurement of the percentage of oxidative and glycolytic fibres and mean diameter of the muscle fibres. In ovo injection of prebiotics Bi2tos had a positive effect on body weight. In prebiotic group (PI) a negative impact on hatchability was observed. Prebiotics and synbiotics had no influence on the yield of the carcass and pectoral muscle. Bioactive compounds had a significant effect on the quality of meat parameters such as: pH 24 h (PI and PB group), L* 45' (SI and SB group), and WHC (groups PB, SI, and SB). The analysis of the enzymatic profile showed a significant increase in the percentage of glycolytic fibres in the pectoral muscle from chicken treated with a synbiotic with the addition of inulin (group SI).

Hydrophobins are low molecular weight proteins secreted by fungi that are extremely surface-active and able to self-assemble into larger structures. Due to their unusual biochemical properties, hydrophobins are an attractive target for commercial applications such as drug emulsification and surface modification. When produced in E. coli, hydrophobins are often not soluble and need to be refolded. In this work we use SHuffle T7 Express E. coli coupled with glutathione redox buffers to produce and refold four distinct class IB hydrophobins that originate from Phanerochaete carnosa (PC1), Wallemia ichthyophaga (WI1), Serpula lacrymans (SL1), and Schizophyllum commune (SC16). Proper refolding and function of these purified hydrophobins was confirmed using nuclear magnetic resonance spectroscopy and thioflavin T assays. These results indicate that class IB hydrophobins can be consistently produced and purified from E. coli, aiding future structural and biochemical studies that require highly pure hydrophobins.

Keywords: Fungi; glutathione redox buffer; hydrophobin; nuclear magnetic resonance spectroscopy; protein refolding; recombinant protein expression.

Background: Despite maturing experience, transseptal puncture (TSP) remains a challenging part of percutaneous left atrial appendage closure (LAAC) and has inherent risks and safety concerns in accessing the left atrium (LA). The VersaCross radiofrequency (RF) system (Baylis Medical), a new RF-tipped pigtail wire-based TSP system, may facilitate LA access by serving as an exchange support wire once access is achieved.

Methods: We retrospectively compared TSP safety and procedural efficiency in 10 consecutive LAAC cases using the VersaCross RF system to 10 cases using the conventional BRK1-XS mechanical needle (Abbott Vascular). The safety and time from femoral access to delivery of the device sheath were compared to the conventional workflow using BRK1-XS/SL1.

Results: We included consecutive 20 cases between July 2019 and November 2019 (12 with WATCHMAN (Boston Scientific, Natick, MA) and 8 with Amulet (St. Jude Medical, St Paul, MN)). Baseline patient characteristics and procedural details were similar in both groups (VersaCross RF system vs. conventional BRK1-XS mechanical needle). All cases were completed successfully with no procedural or in-hospital complications. VersaCross reduced time from femoral access to TSP [4.1 ± 2.5 min vs. 8.4 ± 4.0 min (p = 0.009)] and time from femoral access to delivery sheath access into LA [6.7 ± 2.4 min vs. 13.4 ± 5.4 min (p = 0.002)] compared to BRK1-XS.

Conclusions: Combining a starter wire, transseptal needle and exchange guidewire in the VersaCross RF system enabled faster LA access, which potentially leads to efficient workflow. Further investigation with larger sample size is warranted to corroborate our findings.

Keywords: Atrial fibrillation; Left atrial appendage closure; Transseptal puncture; VersaCross.