A common set of functional characteristics of cancer cells is that cancer cells consume a large amount of glucose, maintain high rate of glycolysis and convert a majority of glucose into lactic acid even in the presence of oxygen compared to that of normal cells (Warburg's Effects). In addition, cancer cells exhibit substantial alterations in several energy metabolism pathways including glucose transport, tricarboxylic acid (TCA) cycle, glutaminolysis, mitochondrial respiratory chain oxidative phosphorylation and pentose phosphate pathway (PPP). In the present work, we focused on reviewing the current knowledge about the dysregulation of the proteins/enzymes involved in the key regulatory steps of glucose transport, glycolysis, TCA cycle and glutaminolysis by several oncogenes including c-Myc and hypoxia inducible factor-1 (HIF-1) and tumor suppressor, p53, in cancer cells. The dysregulation of glucose transport and energy metabolism pathways by oncogenes and lost functions of the tumor suppressors have been implicated as important biomarkers for cancer detection and as valuable targets for the development of new anticancer therapies.

Native wood celluloses can be converted to individual nanofibers 3-4 nm wide that are at least several microns in length, i.e. with aspect ratios>100, by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and successive mild disintegration in water. Preparation methods and fundamental characteristics of TEMPO-oxidized cellulose nanofibers (TOCN) are reviewed in this paper. Significant amounts of C6 carboxylate groups are selectively formed on each cellulose microfibril surface by TEMPO-mediated oxidation without any changes to the original crystallinity (∼74%) or crystal width of wood celluloses. Electrostatic repulsion and/or osmotic effects working between anionically-charged cellulose microfibrils, the ζ-potentials of which are approximately -75 mV in water, cause the formation of completely individualized TOCN dispersed in water by gentle mechanical disintegration treatment of TEMPO-oxidized wood cellulose fibers. Self-standing TOCN films are transparent and flexible, with high tensile strengths of 200-300 MPa and elastic moduli of 6-7 GPa. Moreover, TOCN-coated poly(lactic acid) films have extremely low oxygen permeability. The new cellulose-based nanofibers formed by size reduction process of native cellulose fibers by TEMPO-mediated oxidation have potential application as environmentally friendly and new bio-based nanomaterials in high-tech fields.

The aim of this study was to determine the influence of two key scaffold design parameters, void fraction (VF) and pore size, on the attachment, growth, and extracellular matrix deposition by several cell types. Disc-shaped, porous, poly(-lactic acid) (L-PLA) scaffolds were manufactured by the TheriForm solid free-form fabrication process to generate scaffolds with two VF (75% and 90%) and four pore size distributions (< 38, 38-63, 63-106, and 106-150 microm). Microcomputed tomography analysis revealed that the average pore size was generally larger than the NaCl used, while VF was at or near the designated percentage. The response of three cell types-canine dermal fibroblasts (DmFb), vascular smooth muscle cells (VSMC), or microvascular epithelial cells (MVEC)-to variations in architecture during a 4-week culture period were assessed using histology, metabolic activity, and extracellular matrix deposition as comparative metrics. DmFb, VSMC, and MVEC showed uniform seeding on scaffolds with 90% VF for each pore size, in contrast to the corresponding 75% VF scaffolds. DmFb showed the least selectivity for pore sizes. VSMC displayed equivalent cell proliferation and matrix deposition for the three largest pore sizes. MVEC formed disconnected webs of tissue with sparse extracellular matrix at 90% VF and >38 to 150 microm; however, when cultured on scaffolds with pores formed with salt particles of <38 microm, MVEC formed a multilayered lining on the scaffolds surface. Culture data from scaffolds with a 75% VF suggests that the structural features were unsuitable for tissue formation. Hence, there were limits of acceptable scaffold architecture (VF, pore size) that modulated in vitro cellular responses.

Patients with fractures of the zygomatic bone were treated with high molecular weight poly(L-lactic) acid (PLLA) bone plates and screws. Three years after implantation four patients returned to our department with a swelling at the site of implantation. At the recall of the remaining patients we found an identical type of swelling after the same implantation period. To investigate the nature of the tissue reaction, eight patients were reoperated for the removal of the swelling. The implantation period of the PLLA material varied from 3.3 to 5.7 years. Microscopic evaluation and molecular weight measurements were performed. The excised material showed remnants of degraded PLLA material surrounded by a dense fibrous capsule. Ultrastructural investigation showed crystal-like PLLA material internalized by various cells. The results of this investigation suggest that the PLLA material slowly degrades into particles with a high crystallinity. The intra- and extracellular degradation rate of these particles is very low. After 5.7 years of implantation, these particles were still not fully resorbed.

High concentrations of lactic acid (LA) are found under various pathophysiological conditions and are accompanied by an acidification of the environment. To study the impact of LA on TNF secretion, human LPS-stimulated monocytes were cultured with or without LA or the corresponding pH control. TNF secretion was significantly suppressed by low concentrations of LA (< or = 10 mM), whereas only strong acidification had a similar effect. This result was confirmed in a coculture model of human monocytes with multicellular tumor spheroids. Blocking synthesis of tumor-derived lactate by oxamic acid, an inhibitor of lactate dehydrogenase, reversed the suppression of TNF secretion in this coculture model. We then investigated possible mechanisms underlying the suppression. Uptake of [3-(13)C]lactate by monocytes was shown by hyphenated mass spectrometry. As lactate might interfere with glycolysis, the glycolytic flux of monocytes was determined. We added [1,2-(13)C(2)]glucose to the culture medium and measured glucose uptake and conversion into [2,3-(13)C(2)]lactate. Activation of monocytes increased the glycolytic flux and the secretion of lactate, whereas oxygen consumption was decreased. Addition of unlabeled LA resulted in a highly significant decrease in [2,3-(13)C(2)]lactate secretion, whereas a mere corresponding decrease in pH exerted a less pronounced effect. Both treatments increased intracellular [2,3-(13)C(2)]lactate levels. Blocking of glycolysis by 2-deoxyglucose strongly inhibited TNF secretion, whereas suppression of oxidative phosphorylation by rotenone had little effect. These results support the hypothesis that TNF secretion by human monocytes depends on glycolysis and suggest that LA and acidification may be involved in the suppression of TNF secretion in the tumor environment.

This paper discusses under an energetic perspective the recent and older evidence supporting the classical notion that the 'oxygen debt', as originally defined by Margaria et al. (1933) [Am. J. Physiol. 106, 689-714], consists of two major components: the alactic oxygen debt, with a half-time of the order of 30 sec, and the lactic oxygen debt, with a much longer half-time, similar to that of lactic acid removal from blood after exercise (approximately 15 min). In particular, two ensuing concepts are treated, namely (i) the energetic equivalent of blood lactate accumulation in blood, whence the notions of lactic power and lactic capacity, and (ii) the energy sources allowing contraction of the oxygen deficit at the onset of square-wave exercise. The notion of alactic oxygen deficit is rediscussed on the basis of recent evidence in humans. The analogies between lactate accumulation during supramaximal exercise and during exercise transients are discussed under an energetic perspective.

Autism spectrum disorder (ASD) is a heterogeneous group of complex neurodevelopmental disorders with evidence of genetic predisposition. Intestinal disturbances are reported in ASD patients and compositional changes in gut microbiota are described. However, the role of microbiota in brain disorders is poorly documented. Here, we used a murine model of ASD to investigate the relation between gut microbiota and autism-like behaviour. Using next generation sequencing technology, microbiota composition was investigated in mice in utero exposed to valproic acid (VPA). Moreover, levels of short chain fatty acids (SCFA) and lactic acid in caecal content were determined. Our data demonstrate a transgenerational impact of in utero VPA exposure on gut microbiota in the offspring. Prenatal VPA exposure affected operational taxonomic units (OTUs) assigned to genera within the main phyla of Bacteroidetes and Firmicutes and the order of Desulfovibrionales, corroborating human ASD studies. In addition, OTUs assigned to genera of Alistipes, Enterorhabdus, Mollicutes and Erysipelotrichalis were especially associated with male VPA-exposed offspring. The microbial differences of VPA in utero-exposed males deviated from those observed in females and was (i) positively associated with increased levels of caecal butyrate as well as ileal neutrophil infiltration and (ii) inversely associated with intestinal levels of serotonin and social behaviour scores. These findings show that autism-like behaviour and its intestinal phenotype is associated with altered microbial colonization and activity in a murine model for ASD, with preponderance in male offspring. These results open new avenues in the scientific trajectory of managing neurodevelopmental disorders by gut microbiome modulation.

Lactic acid bacteria (LAB) are well recognized beneficial host-associated members of the microbiota of humans and animals. Yet LAB-associations of invertebrates have been poorly characterized and their functions remain obscure. Here we show that honeybees possess an abundant, diverse and ancient LAB microbiota in their honey crop with beneficial effects for bee health, defending them against microbial threats. Our studies of LAB in all extant honeybee species plus related apid bees reveal one of the largest collections of novel species from the genera Lactobacillus and Bifidobacterium ever discovered within a single insect and suggest a long (>80 mya) history of association. Bee associated microbiotas highlight Lactobacillus kunkeei as the dominant LAB member. Those showing potent antimicrobial properties are acquired by callow honey bee workers from nestmates and maintained within the crop in biofilms, though beekeeping management practices can negatively impact this microbiota. Prophylactic practices that enhance LAB, or supplementary feeding of LAB, may serve in integrated approaches to sustainable pollinator service provision. We anticipate this microbiota will become central to studies on honeybee health, including colony collapse disorder, and act as an exemplar case of insect-microbe symbiosis.

BACKGROUND

Microbial infection of the pancreatic tissue in patients with severe acute pancreatitis increases the morbidity and mortality rates. Colonization of the lower gastrointestinal tract and oropharynx with Gram-negative, but sometimes also Gram-positive, bacteria precedes contamination of the pancreas. The aim of this study was to determine whether lactic acid bacteria such as Lactobacillus plantarum 299 could prevent colonization of the gut by potential pathogens and thus reduce the endotoxaemia associated with acute pancreatitis.

METHODS

Patients with acute pancreatitis were randomized into two double-blind groups. The treatment group received a freeze-dried preparation containing live L. plantarum 299 in a dose of 109 organisms, together with a substrate of oat fibre, for 1 week by nasojejunal tube. The control group received a similar preparation but the Lactobacillus was inactivated by heat.

RESULTS

A total of 45 patients completed the study. Twenty-two patients received treatment with live and 23 with heat-killed L. plantarum 299. Infected pancreatic necrosis and abscesses occurred in one of 22 patients in the treatment group, compared with seven of 23 in the control group (P = 0.023). The mean length of stay was 13.7 days in the treatment group versus 21.4 days in the control group (P not significant).

CONCLUSIONS

Supplementary L. plantarum 299 was effective in reducing pancreatic sepsis and the number of surgical interventions.

OBJECTIVE

To study the bacterial diversity in expressed human milk with a focus on detecting bacteria with an antimicrobial activity against Staphylococcus aureus, known as a causative agent of maternal breast infections and neonatal infections.

RESULTS

Random isolates (n = 509) were collected from breast milk samples (n = 40) of healthy lactating women, genotypically identified, and tested for antimicrobial activity against Staph. aureus. Commensal staphylococci (64%) and oral streptococci (30%), with Staph. epidermidis, Strep. salivarius, and Strep. mitis as the most frequent isolates, were the predominant bacterial species in breast milk. One-fifth of Staph. epidermidis and half of Strep. salivarius isolates suppressed growth of Staph. aureus. Enterococci (Ent. faecalis), isolated from 7.5% of samples, and lactic acid bacteria (LAB) (Lactobacillus rhamnosus, Lact. crispatus, Lactococcus lactis, Leuconoctoc mesenteroides), isolated from 12.5% of samples, were also effective against Staph. aureus. One L. lactis isolate was shown to produce nisin, a bacteriocin used in food industry to prevent bacterial pathogens and spoilage.

CONCLUSIONS

Expressed breast milk contains commensal bacteria, which inhibit Staph. aureus.

CONCLUSIONS

The strains inhibitory against the pathogen Staph. aureus have potential use as bacteriotherapeutic agents in preventing neonatal and maternal breast infections caused by this bacterium.

Lactobacillus plantarum is a flexible and versatile microorganism that inhabits a variety of environmental niches, including the human gastrointestinal (GI) tract. Moreover, this lactic acid bacterium can survive passage through the human or mouse stomach in an active form. To investigate the genetic background of this persistence, resolvase-based in vivo expression technology (R-IVET) was performed in L. plantarum WCFS1 by using the mouse GI tract as a model system. This approach identified 72 L. plantarum genes whose expression was induced during passage through the GI tract as compared to laboratory media. Nine of these genes encode sugar-related functions, including ribose, cellobiose, sucrose, and sorbitol transporter genes. Another nine genes encode functions involved in acquisition and synthesis of amino acids, nucleotides, cofactors, and vitamins, indicating their limited availability in the GI tract. Four genes involved in stress-related functions were identified, reflecting the harsh conditions that L. plantarum encounters in the GI tract. The four extracellular protein encoding genes identified could potentially be involved in interaction with host specific factors. The rest of the genes are part of several functionally unrelated pathways or encode (conserved) hypothetical proteins. Remarkably, a large number of the functions or pathways identified here have previously been identified in pathogens as being important in vivo during infection, strongly suggesting that survival rather than virulence is the explanation for the importance of these genes during host residence.

Coenzyme Q(10) is a mobile lipophilic electron carrier located in the inner mitochondrial membrane. Defects of coenzyme Q(10) biosynthesis represent one of the few treatable mitochondrial diseases. We genotyped a patient with primary coenzyme Q(10) deficiency who presented with neonatal lactic acidosis and later developed multisytem disease including intractable seizures, global developmental delay, hypertrophic cardiomyopathy, and renal tubular dysfunction. Cultured skin fibroblasts from the patient had a coenzyme Q(10) biosynthetic rate of 11% of normal controls and accumulated an abnormal metabolite that we believe to be a biosynthetic intermediate. In view of the rarity of coenzyme Q(10) deficiency, we hypothesized that the disease-causing gene might lie in a region of ancestral homozygosity by descent. Data from an Illumina HumanHap550 array were analyzed with BeadStudio software. Sixteen regions of homozygosity >1.5 Mb were identified in the affected infant. Two of these regions included the loci of two of 16 candidate genes implicated in human coenzyme Q(10) biosynthesis. Sequence analysis demonstrated a homozygous stop mutation affecting a highly conserved residue of COQ9, leading to the truncation of 75 amino acids. Site-directed mutagenesis targeting the equivalent residue in the yeast Saccharomyces cerevisiae abolished respiratory growth.

A new bacteriocin has been isolated from an Enterococcus faecium strain. The bacteriocin, termed enterocin A, was purified to homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and mass spectrometry analysis. By combining the data obtained from amino acid and DNA sequencing, the primary structure of enterocin A was determined. It consists of 47 amino acid residues, and the molecular weight was calculated to be 4,829, assuming that the four cysteine residues form intramolecular disulfide bridges. This molecular weight was confirmed by mass spectrometry analysis. The amino acid sequence of enterocin A shared significant homology with a group of bacteriocins (now termed pediocin-like bacteriocins) isolated from a variety of lactic acid-producing bacteria, which include members of the genera Lactobacillus, Pediococcus, Leuconostoc, and Carnobacterium. Sequencing of the structural gene of enterocin A, which is located on the bacterial chromosome, revealed an N-terminal leader sequence of 18 amino acid residues, which was removed during the maturation process. The enterocin A leader belongs to the double-glycine leaders which are found among most other small nonlantibiotic bacteriocins, some lantibiotics, and colicin V. Downstream of the enterocin A gene was located a second open reading frame, encoding a putative protein of 103 amino acid residues. This gene may encode the immunity factor of enterocin A, and it shares 40% identity with a similar open reading frame in the operon of leucocin AUL 187, another pediocin-like bacteriocin.

The concept of biodegradable plastics is of considerable interest with respect to solid waste accumulation. Greater efforts have been made in developing degradable biological materials without any environmental pollution to replace oil-based traditional plastics. Among numerous kinds of degradable polymers, polylactic acid sometimes called polylactide, an aliphatic polyester and biocompatible thermoplastic, is currently a most promising and popular material with the brightest development prospect and was considered as the 'green' eco friendly material. Biodegradable plastics like polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyrate, etc. are commercially available for controlled drug releases, implantable composites, bone fixation parts, packaging and paper coatings, sustained release systems for pesticides and fertilizers and compost bags etc. This review will provide information on current PLA market, brief account on recent developments in the synthesis of lactic acid (monomer of PLA) through biological route, PLA synthesis, unique material properties of PLA and modification of those by making copolymers and composites, PLA degradation and its wide spectrum applications.

The aim of the present work was to assess the merits of PEGylated poly(lactic-co-glycolic acid) (PEG-PLGA) nanoparticles as protein and peptide drugs (PPD) carriers. PEG-PLGA copolymer, which could be used to prepare the stealth nanoparticles or long-circulating nanoparticles, was synthesized with methoxypolyethyleneglycol (MePEG) and PLGA. The structure of PEG-PLGA was confirmed with (1)H NMR and Fourier transform infrared (FTIR) spectrum, and molecular weight was determined by gel permeation chromatography (GPC). Bovine serum albumin (BSA), chosen as model protein, was encapsulated within the stealth nanoparticles with the double emulsion method. The particles were characterized in terms of size, zeta potential and in vitro release of the protein. The biological fate of the BSA-loaded nanoparticles following intravenous administration was determined over 24 h in rats. The experimental results showed that PEG-PLGA could be obtained by ring-opening polymerization of lactide and glycolide in the presence of MePEG. (1)H NMR and FTIR spectrum were consistent with the structure of PEG-PLGA copolymer. Molecular weight determined by GPC was 50800. The stealth nanoparticles loading BSA could be prepared by the double emulsion technique. The entrapment efficiency was 48.6%, particle size about 200 nm and zeta potential -16.1 mV. BSA release from the stealth nanoparticles showed an initial burst release and then sustained release. PEG-PLGA nanoparticles could extend half-life of BSA from 13.6 min of loaded in PLGA nanoparticles to 4.5 h and obviously change the protein biodistribution in rats compared with that of PLGA nanoparticles. Thus, PEG-PLGA nanoparticles could be an effective carrier for PPD delivery.

Nano-fibrous poly(L-lactic acid) (PLLA) scaffolds with interconnected pores were developed under the hypothesis that nano-fibrous scaffolding would mimic a morphological function of collagen fibrils to create a more favorable microenvironment for cells versus solid-walled scaffolds. In this study, an in vitro system was used to examine biological properties of the nano-fibrous scaffolds compared with those of solid-walled scaffolds for their potential use in bone tissue engineering. Biomineralization was enhanced substantially on the nano-fibrous scaffolds compared to solid-walled scaffolds, and this was confirmed by von Kossa staining, measurement of calcium contents, and transmission electron microscopy. In support of this finding, osteoblasts cultured on the nano-fibrous scaffolds exhibited higher alkaline phosphatase activity and an earlier and enhanced expression of the osteoblast phenotype versus solid-walled scaffolds. Most notable were the increases in runx2 protein and in bone sialoprotein mRNA in cells cultured on nano-fibrous scaffolds versus solid-walled scaffolds. At the day 1 of culture, alpha2 and beta1 integrins as well as alphav and beta3 integrins were highly expressed on the surface of cells seeded on nano-fibrous scaffolds, and linked to this were higher levels of phospho-Paxillin and phospho-FAK in cell lysates. In contrast, cells seeded on solid-walled scaffolds expressed significantly lower levels of these integrins, phospho-Paxillin, and phospho-FAK. To further examine the role of nano-fibrous architecture, we inhibited the formation of collagen fibrils by adding 3,4-dehydroproline to cultures and then assayed cells for expression of alpha2 integrin. Cells seeded on nano-fibrous scaffolds sustained expression of alpha2 integrin in the presence of dehydroproline, while suppression of alpha2 integrin was evident in cells seeded on solid-walled scaffolds. These results provide initial evidence that synthetic nano fibers may exhibit certain properties that are comparable to natural collagen fibers, and thus, the nano-fibrous architecture may serve as a superior scaffolding versus solid-walled architecture for promoting osteoblast differentiation and biomineralization.

A transcriptional fusion vector, designated pNZ272, based on the promoterless beta-glucuronidase gene (gusA) of Escherichia coli as a reporter gene, has been constructed for lactic acid bacteria. The replicon of pNZ272 was derived from the Lactococcus lactis plasmid pSH71, allowing replication in a wide range of gram-positive bacteria and E. coli. The applicability of pNZ272 and the expression of the gusA gene in L. lactis was demonstrated in shotgun cloning experiments with lactococcal chromosomal and bacteriophage DNA. In addition, three defined lactococcal promoters were inserted in pNZ272: the plasmid-derived lacA promoter, the chromosomal usp45 promoter, and a promoter from bacteriophage phi SK11G. The three resulting plasmids showed beta-glucuronidase activity in a gusA-deficient E. coli strain and in four species of lactic acid bacteria belonging to the genera Lactobacillus, Lactococcus, and Leuconostoc. The copy numbers of the gusA-expressing plasmids were similar within a single species of lactic acid bacteria. However, the specific beta-glucuronidase activity and the gusA mRNA levels varied considerably both within a single species and among different species of lactic acid bacteria. The transcriptional start site of all three promoters was determined and found to be identical in the different species. The results of this comparative promoter analysis indicate that the requirements for efficient transcription initiation differ among the lactic acid bacteria studied.

The classical "oxygen debt" hypothesis formulated by Hill and associates in the 1920s was an attempt to link the metabolism of lactic acid with the O2 consumption in excess of resting that occurs after exercise. The O2 debt was hypothesized to represent the oxidation of a minor fraction (1/5) of the lactate formed during exercise, to provide the energy to reconvert the remainder (4/5) of the lactate to glycogen during recovery. In 1933 Margaria et al. modified this hypothesis by distinguishing between initial, fast ("alactacid"), and second, slow ("lactacid"), O2-debt curve components. They hypothesized that the fast phase of the post-exercise O2 consumption curve was due to the restoration of phosphagen (ATP + CP). It is now probable that the original lactic acid explanation of the O2 debt was too simplistic. Numerous studies on several species have provided evidence demonstrating a dissociation between the kinetics of lactate removal and the slow component of the post-exercise VO2. The metabolism of lactate, a readily oxidizable substrate, following exercise appears to be directed primarily toward energy production in mitochondria. The elevated concentration of lactate present at the end of exercise may be viewed as a "reservoir of carbon," which may serve as a source of oxidative ATP production or as a source of carbon skeletons for the synthesis of glucose, glycogen, amino acids, and TCA cycle intermediates. The metabolic basis of the elevated post-exercise VO2 may be understood in terms of those factors which directly or indirectly influence mitochondrial O2 consumption. Included among these factors are catecholamines, thyroxine, glucocorticoids, fatty acids, calcium ions, and temperature. Of these, elevated temperature is perhaps the most important. As no complete explanation of the post-exercise metabolism exists, it is recommended that the term "O2 debt" be used to describe a set of phenomena during recovery from exercise. The terms "alactacid debt" and "lactacid debt," which suggest a mechanism, are inappropriate. Use of alternative terms, e.g., "excess post-exercise oxygen consumption" (EPOC) and "recovery O2," will avoid implication of causality in describing the elevation in metabolic rate above resting levels after exercise.

Tendon is a specific connective tissue composed of parallel collagen fibers. The effect of this tissue-specific matrix orientation on stem cell differentiation has not been investigated. This study aimed to determine the effects of nanotopography on the differentiation of human tendon stem/progenitor cells (hTSPCs) and develop a biomimetic scaffold for tendon tissue engineering. The immuno-phenotype of fetal hTSPCs was identified by flow cytometry. The multipotency of hTSPCs toward osteogenesis, adipogenesis, and chondrogenesis was confirmed. Then, the hTSPCs were seeded onto aligned or randomly-oriented poly (l-lactic acid) nanofibers. Scanning electron micrographs showed that hTSPCs were spindle-shaped and well orientated on the aligned nanofibers. The expression of tendon-specific genes was significantly higher in hTSPCs growing on aligned nanofibers than those on randomly-oriented nanofibers in both normal and osteogenic media. In addition, alkaline phosphatase activity and alizarin red staining showed that the randomly-oriented fibrous scaffold induced osteogenesis, while the aligned scaffold hindered the process. Moreover, aligned cells expressed significantly higher levels of integrin alpha1, alpha5 and beta1 subunits, and myosin II B. In in vivo experiments, the aligned nanofibers induced the formation of spindle-shaped cells and tendon-like tissue. In conclusion, the aligned electrospun nanofiber structure provides an instructive microenvironment for hTSPC differentiation and may lead to the development of desirable engineered tendons.

Injectable biodegradable polymeric particles (usually microspheres) represent an exciting approach to control the release of vaccine antigens to reduce the number of doses in the immunization schedule and optimize the desired immune response via selective targeting of antigen to antigen presenting cells. After the first couple of decades of their study, much progress has been made towards the clinical use of antigen-loaded microspheres. Poly(lactide-co-glycolic acids) (PLGAs) have been studied most commonly for this purpose because of their proven safety record and established use in marketed products for controlled delivery of several peptide drugs. PLGA microspheres have many desirable features relative to standard aluminum-based adjuvants, including the microspheres' ability to induce cell-mediated immunity, a necessary requirement for emergent vaccines against HIV and cancer. This review examines several impediments to PLGA microparticle development, such as PLGA-encapsulated antigen instability and deficiency of animal models in predicting human response, and describes new trends in overcoming these important issues. PLGA microparticles have displayed unprecedented versatility and safety to accomplish release of one or multiple antigens of varying physical-chemical characteristics and immunologic requirements, and have now met numerous critical benchmarks in development of long-lasting immunity after a single injected dose.

Microbial production of organic acids is a promising approach for obtaining building-block chemicals from renewable carbon sources. Although some acids have been produced for some time and in-depth knowledge of these microbial production processes has been gained, further microbial production processes seem to be feasible, but large-scale production has not yet been possible. Citric, lactic and succinic acid production exemplify three processes in different stages of industrial development. Although the questions being addressed by current research on these processes are diverging, a comparison is helpful for understanding microbial organic acid production in general. In this article, through analysis of the current advances in production of these acids, we present guidelines for future developments in this fast-moving field.

Objective: To explore the clinical characteristics and prognosis of the new coronavirus 2019-nCoV patients combined with cardiovascular disease (CVD). Methods: A retrospective analysis was performed on 112 COVID-19 patients with CVD admitted to the western district of Union Hospital in Wuhan, from January 20, 2020 to February 15, 2020. They were divided into critical group (ICU, n=16) and general group (n=96) according to the severity of the disease and patients were followed up to the clinical endpoint. The observation indicators included total blood count, C-reactive protein (CRP), arterial blood gas analysis, myocardial injury markers, coagulation function, liver and kidney function, electrolyte, procalcitonin (PCT), B-type natriuretic peptide (BNP), blood lipid, pulmonary CT and pathogen detection. Results: Compared with the general group, the lymphocyte count (0.74×10(9) (0.34×10(9), 0.94×10(9))/L vs. 0.99×10(9) (0.71×10(9), 1.29×10(9))/L, P=0.03) was extremely lower in the critical group, CRP (106.98 (81.57, 135.76) mg/L vs. 34.34 (9.55,76.54) mg/L, P<0.001) and PCT (0.20 (0.15,0.48) μg/L vs. 0.11 (0.06,0.20)μg/L, P<0.001) were significantly higher in the critical group. The BMI of the critical group was significantly higher than that of the general group (25.5 (23.0, 27.5) kg/m(2) vs. 22.0 (20.0, 24.0) kg/m(2), P=0.003). Patients were further divided into non-survivor group (17, 15.18%) group and survivor group (95, 84.82%). Among the non-survivors, there were 88.24% (15/17) patients with BMI> 25 kg/m(2), which was significantly higher than that of survivors (18.95% (18/95), P<0.001). Compared with the survived patients, oxygenation index (130 (102, 415) vs. 434 (410, 444), P<0.001) was significantly lower and lactic acid (1.70 (1.30, 3.00) mmol/L vs. 1.20 (1.10, 1.60) mmol/L, P<0.001) was significantly higher in the non-survivors. There was no significant difference in the proportion of ACEI/ARB medication between the critical group and the general group or between non-survivors and survivors (all P>0.05). Conclusion: COVID-19 patients combined with CVD are associated with a higher risk of mortality. Critical patients are characterized with lower lymphocyte counts. Higher BMI are more often seen in critical patients and non-survivor. ACEI/ARB use does not affect the morbidity and mortality of COVID-19 combined with CVD. Aggravating causes of death include fulminant inflammation, lactic acid accumulation and thrombotic events.

Antibiotics are a major tool utilized by the health care industry to fight bacterial infections; however, bacteria are highly adaptable creatures and are capable of developing resistance to antibiotics. Consequently, decades of antibiotic use, or rather misuse, have resulted in bacterial resistance to many modern antibiotics. This antibiotic resistance can cause significant danger and suffering for many people with common bacterial infections, those once easily treated with antibiotics. For several decades studies on selection and dissemination of antibiotic resistance have focused mainly on clinically relevant species. However, recently many investigators have speculated that commensal bacteria including lactic acid bacteria (LAB) may act as reservoirs of antibiotic resistance genes similar to those found in human pathogens. The main threat associated with these bacteria is that they can transfer resistance genes to pathogenic bacteria. Genes conferring resistance to tetracycline, erythromycin and vancomycin have been detected and characterized in Lactococcus lactis, Enterococci and, recently, in Lactobacillus species isolated from fermented meat and milk products. A number of initiatives have been recently launched by various organizations across the globe to address the biosafety concerns of starter cultures and probiotic microorganisms. The studies can lead to better understanding of the role played by the dairy starter microorganisms in horizontal transfer of antibiotic resistance genes to intestinal microorganisms and food-associated pathogenic bacteria.

A transferable dual-plasmid inducible gene expression system for use in lactic acid bacteria that is based on the autoregulatory properties of the antimicrobial peptide nisin produced by Lactococcus lactis was developed. Introduction of the two plasmids allowed nisin-inducible gene expression in Lactococcus lactis MG1363, Leuconostoc lactis NZ6091, and Lactobacillus helveticus CNRZ32. Typically, the beta-glucuronidase activity (used as a reporter in this study) remained below the detection limits under noninducing conditions and could be raised to high levels, by addition of subinhibitory amounts of nisin to the growth medium, while exhibiting a linear dose-response relationship. These results demonstrate that the nisin-inducible system can be functionally implemented in lactic acid bacteria other than Lactococcus lactis.