Molecular-based phenotype variations in amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is one of the typical dental genetic diseases in human. It can occur isolatedly or as part of a syndrome. Previous reports have mainly clarified the types and mechanisms of nonsyndromic AI. This review aimed to compare the phenotypic differences among the hereditary enamel defects with or without syndromes and their underlying pathogenic genes. We searched the articles in PubMed with different strategies or keywords including but not limited to amelogenesis imperfecta, enamel defects, hypoplastic/hypomaturation/hypocalcified, syndrome, or specific syndrome name. The articles with detailed clinical information about the enamel and other phenotypes and clear genetic background were used for the analysis. We totally summarized and compared enamel phenotypes of 18 nonsyndromic AI with 17 causative genes and 19 syndromic AI with 26 causative genes. According to the clinical features, radiographic or ultrastructural changes in enamel, the enamel defects were basically divided into hypoplastic and hypomineralized (hypomaturated and hypocalcified) and presented a higher heterogeneity which were closely related to the involved pathogenic genes, types of mutation, hereditary pattern, X chromosome inactivation, incomplete penetrance, and other mechanisms.The gene-specific enamel phenotypes could be an important indicator for diagnosing nonsyndromic and syndromic AI.

MSX1 involved selective tooth agenesis and abnormal labial frenum, pedigree, and retrospective study.

OBJECTIVE: Muscle segment homeobox gene 1 (MSX1) is widely expressed in craniofacial development and tooth formation. The aim of this study was to report a novel MSX1 mutation in a Chinese family with selective tooth agenesis and abnormal median maxillary labial frenum (MMLF). MATERIALS AND METHODS: Mutation analysis was carried out by whole exome sequencing. The pMD18-T vector was used to verify the mutations. PubMed and Human Gene Mutation Database were searched to analyze the relationship between the mutations in MSX1 and related phenotypes. RESULTS: A novel heterozygous mutation (c.75delG) in MSX1 was detected in the proband and her mother. They presented as oligodontia and lower attached hypertrophy median maxillary labial frenum. 60 MSX1 mutations from 39 reports did not declare malformed MMLF except our cases. Meanwhile, we found that the types and sites of MSX1 mutations may affect the selectivity of tooth agenesis and orofacial cleft. CONCLUSION: This study suggests malformed MMLF as a new phenotype of MSX1 mutation and a specific relationship between MSX1 genotype and phenotype.

The effect of liposomal bupivacaine for surgical wound infiltration: A meta-analysis of randomised controlled trials.

Liposomal bupivacaine (LB) has consistently been considered a potential analgesic for surgical wound infiltration. However, the evidence of its analgesic effectiveness remains unclear. In this meta-analysis, we attempted to identify the potential clinical role of LB wound infiltration in different surgical procedures. Randomised controlled trials (RCTs) comparing LB with non-liposomal local anaesthetics and placebos were retrieved from six electronic databases. The primary outcome was cumulative morphine equivalent consumption within 24, 48, and 72 hours after surgery. Approximately 2659 patients from 22 studies were included in the meta-analysis. Compared to the control, LB-wound infiltration did not reduce the postoperative morphine consumption at 24 hours (weighted mean difference [WMD], -0.60 mg; 97.5% confidence interval [CI], -2.78 to 1.59 mg; P = 0.54), 48 hours (WMD, -1.00 mg; 97.5% CI, -3.23 to 1.24; P = 0.32) or 72 hours (WMD, 0.50 mg; 97.5% CI, -0.67 to 1.67; P = 0.33). Similarly, secondary outcome analysis did not reveal any additional benefits of LB in any other pain-related outcomes. LB was not associated with any adverse effects. Overall, LB does not appear to improve the postoperative analgesic, rehabilitation, or safety outcomes. Current evidence does not support the routine use of LB for wound infiltration following surgical procedures.

Feasibility and Safety of Tethered Capsule Endomicroscopy in Patients With Barrett's Esophagus in a Multi-Center Study.

BACKGROUND & AIMS: Tethered capsule endomicroscopy (TCE) involves swallowing a small tethered pill that implements optical coherence tomography (OCT) imaging, procuring high resolution images of the whole esophagus. Here, we demonstrate and evaluate the feasibility and safety of TCE and a portable OCT imaging system in patients with Barrett's esophagus (BE) in a multi-center (5-site) clinical study. METHODS: Untreated patients with BE as per endoscopic biopsy diagnosis were eligible to participate in the study. TCE procedures were performed in unsedated patients by either doctors or nurses. After the capsule was swallowed, the device continuously obtained 10-µm-resolution cross-sectional images as it traversed the esophagus. Following imaging, the device was withdrawn through mouth, and disinfected for subsequent reuse. BE lengths were compared to endoscopy findings when available. OCT-TCE images were compared to volumetric laser endomicroscopy (VLE) images from a patient who had undergone VLE on the same day as TCE. RESULTS: 147 patients with BE were enrolled across all sites. 116 swallowed the capsule (79%), 95/114 (83.3%) men and 21/33 (63.6%) women (P = .01). High-quality OCT images were obtained in 104/111 swallowers (93.7%) who completed the procedure. The average imaging duration was 5.55 ± 1.92 minutes. The mean length of esophagus imaged per patient was 21.69 ± 5.90 cm. A blinded comparison of maximum extent of BE measured by OCT-TCE and EGD showed a strong correlation (r = 0.77-0.79). OCT-TCE images were of similar quality to those obtained by OCT-VLE. CONCLUSIONS: The capabilities of TCE to be used across multiple sites, be administered to unsedated patients by either physicians or nurses who are not expert in OCT-TCE, and to rapidly and safely evaluate the microscopic structure of the esophagus make it an emerging tool for screening and surveillance of BE patients. Clinical trial registry website and trial number: NCT02994693 and NCT03459339.

Development of a novel drug targeting delivery system for cervical cancer therapy.

'Targeting peptides' have demonstrated their value in diagnostic imaging and therapy and novel peptide probes specific to cervical cancer were developed. In the M13KE phage dodecapeptide (12-mer) peptide library, the phage clone S7 showed the best binding to the cancer cells as confirmed by immunofluorescence and flow cytometry assays, and was selected for continued studies. Its binding peptide, CSP3, was synthesized from the sequence of S7's 12-mer at the N-terminus of the minor coat protein pIII of this M13KE phage vector. The peptide's binding was analyzed by the same assays used for S7. It was also assessed using competitive inhibition and binding to a tissue chip. The results demonstrated that the CSP3 peptide bound to cervical carcinoma cells with high sensitivity and specificity. The positive results indicated that the peptide CSP3, conjugated with nanomaterials and chemotherapeutics, may be developed as a targeting vehicle for therapeutic drug delivery against cervical cancer, especially cervical cancer with multiple drug resistance. For this aim, we prepared a CSP3 conjugated liposome drug delivery system containing doxorubicin (DOX) and microRNA101 (miR101) expression plasmids (CSP3-Lipo-DOX-miR101), and the primary result showed that the system demonstrated significantly enhanced cytotoxicity to SiHa cells and DOX resistant SiHa cells, SiHa/ADR. Our results showed that CSP3 is a cervical cancer targeting 12aa peptide with high specificity and sensitivity, and the CSP3 conjugated drug delivery system, CSP3-Lipo-DOX-miR101 has promising potential for development as an efficient drug system for the therapy of cervical cancer.

Thrombotic Thrombocytopenic Purpura Associated With Pegylated Interferon Alfa-2a Use in a Patient With Polycythemia Vera.

Pegylated interferon alfa-2a (pegIFNa) is being increasingly used for treatment of myeloproliferative neoplasms; however, its side effects, including autoimmune complications, are not unusual. We report on a 47-year-old woman with polycythemia vera (PV) treated with pegIFNa and in complete hematologic remission who developed thrombotic thrombocytopenic purpura (TTP). To our knowledge, thrombotic microangiopathy has been reported as a side effect of interferon (IFN) use in patients with hepatitis and chronic myeloid leukemia, but not in those with PV. Our patient had a low ADAMTS13 level due to an inhibitor, which normalized after withholding pegIFNa and initiating treatment for TTP with therapeutic plasma exchange and corticosteroids. She experienced refractory TTP, necessitating treatment with rituximab and splenectomy. Postsplenectomy, she developed a high platelet count, warranting the need to restart treatment for PV. However, JAK2V617F allelic burden by real-time PCR was 0.7%, indicating that the increased platelet count was likely secondary to splenectomy. Therefore, we elected to monitor her counts and JAK2V617F allelic burden closely. With this case report, we hope to alert treating physicians that TTP should be considered as a complication of pegIFNa therapy in PV and that prompt discontinuation of the drug with necessary treatment should be instituted to prevent fatal complications.

The novel human ß-defensin 114 regulates lipopolysaccharide (LPS)-mediated inflammation and protects sperm from motility loss.

Lipopolysaccharide (LPS) is an important pathological factor involved in serious inflammatory diseases and male reproductive impairments. Emerging evidence demonstrates that antimicrobial peptides possess protective activity in response to LPS-induced inflammation. However, the LPS-binding and/or immunosuppressive activity of ß-defensins (DEFBs) has been underestimated. In the present work, we characterized a novel human defensin, DEFB114, which was expressed predominantly in the epididymis and gingival cells at the RNA level. Homogenous recombinant DEFB114 peptides were prepared and characterized using mass spectrometry. DEFB114 protein exhibited a broad spectrum of antimicrobial activity with salt sensitivity against typical pathogenic microbes (i.e. Escherichia coli, Staphylococcus aureus, and Candida albicans). Interestingly, DEFB114 demonstrated novel LPS-binding activity in vitro and inhibited TNF-α release in RAW264.7 cultures through the inhibition of MAPK p42/44 when challenged with LPS. Moreover, DEFB114 could also rescue the LPS-induced reduction of human sperm motility in vitro and protect d-galactosamine-sensitized C57BL/6 mice from LPS-induced lethality in vivo. The protective activity of DEFB114 on RAW264.7, human sperm, and the d-galactosamine-sensitized mice was disulfide bond-dependent because alkylated DEFB114 lost its activity. The low cytotoxicity of the DEFB114 peptide toward human erythrocytes is indicative of its potential therapeutic use in the treatment of LPS-induced inflammation, LPS contamination, and potentially septic shock.

Oroxylin A inhibits hemolysis via hindering the self-assembly of α-hemolysin heptameric transmembrane pore.

Alpha-hemolysin (α-HL) is a self-assembling, channel-forming toxin produced by most Staphylococcus aureus strains as a 33.2-kDa soluble monomer. Upon binding to a susceptible cell membrane, the monomer self-assembles to form a 232.4-kDa heptamer that ultimately causes host cell lysis and death. Consequently, α-HL plays a significant role in the pathogenesis of S. aureus infections, such as pneumonia, mastitis, keratitis and arthritis. In this paper, experimental studies show that oroxylin A (ORO), a natural compound without anti-S. aureus activity, can inhibit the hemolytic activity of α-HL. Molecular dynamics simulations, free energy calculations, and mutagenesis assays were performed to understand the formation of the α-HL-ORO complex. This combined approach revealed that the catalytic mechanism of inhibition involves the direct binding of ORO to α-HL, which blocks the conformational transition of the critical "Loop" region of the α-HL protein thereby inhibiting its hemolytic activity. This mechanism was confirmed by experimental data obtained from a deoxycholate-induced oligomerization assay. It was also found that, in a co-culture system with S. aureus and human alveolar epithelial (A549) cells, ORO could protect against α-HL-mediated injury. These findings indicate that ORO hinders the lytic activity of α-HL through a novel mechanism, which should facilitate the design of new and more effective antibacterial agents against S. aureus.

A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite derived from lignin: an efficient peroxymonosulfate activator for naphthalene degradation.

A novel 3D nitrogen-doped porous carbon supported Fe-Cu bimetallic nanoparticles composite (Fe-Cu-N-PC) was prepared via direct pyrolysis by employing black liquor lignin as a main precursor, and it was utilized as a novel catalyst for PMS activation in degrading naphthalene. Under the optimum experimental conditions, the naphthalene degradation rate was up to 93.2% within 60 min in the Fe-Cu-N-PC/PMS system. The porous carbon framework of Fe-Cu-N-PC could facilitate the quick molecule diffusion of reactants towards the inner bimetallic nanoparticles and enriched naphthalene molecules from the solution by a specific adsorption, which increased the odds of contact between naphthalene and reactive oxygen species and improved the reaction efficiency. The quenching reaction proved that the non-free radical pathway dominated by 1O2 was the main way in naphthalene degradation, while the free radical pathway involving SO4·- and ·OH only played a secondary role. Moreover, owing to its high magnetization performance, Fe-Cu-N-PC could be magnetically recovered and maintained excellent naphthalene degradation rate after four degradation cycles. This research will offer a theoretical basis for the construction of facile, efficient, and green technologies to remediate persistent organic pollutants in the environment.

Sensing of glycoprotein via a biomimetic sensor based on molecularly imprinted polymers and graphene-Au nanoparticles.

A novel strategy was proposed for preparing a highly sensitive glycoprotein sensor based on molecularly imprinted polymers (MIP), which was electropolymerized with o-phenylenediamine and 3-aminophenylboronic acid monohydrate in the presence of template molecules (bovine serum albumin (BSA)). Sensitivity improved dramatically owing to the application of a graphene-Au nanoparticles hybrid as the electrode modifier, and the immobilization of a large amount of 6-ferrocenylhexanethiol, as the electroactive species, onto nanoparticles. The quantification of BSA was realized by detecting the electrochemical oxidation signal of 6-ferrocenylhexanethiol, which was bonded onto the electrode. Under optimized conditions, a good relationship was obtained between the response current and logarithm of BSA concentration in the range of 1.0 × 10(-11) to 1.0 × 10(-5) g mL(-1) with a detection limit of 7.5 × 10(-12) g mL(-1) (S/N = 3). The resulting MIP sensor displayed good selectivity, reproducibility and stability.

Preparation of a butyl-silica hybrid monolithic column with a "one-pot" process for bioseparation by capillary liquid chromatography.

A butyl-silica hybrid monolithic column for bioseparation by capillary liquid chromatography (cLC) was prepared with butyl methacrylate and alkoxysilanes through a "one-pot" process. The effects of polycondensation temperature, volume percentage of N,N'-dimethylformamide, and content of cetyltrimethylammonium bromide and butyl methacrylate on the morphologies of the hybrid monolithic columns prepared were investigated in detail. Baseline separations of proteins and small peptides on the hybrid monolithic column were achieved by cLC with gradient elution. In addition, the resulting hybrid column was also applied for analysis of tryptic digests of bovine serum albumin by cLC coupled with tandem mass spectrometry. The results demonstrate its potential application in separation of complex biological samples.

Airway inflammation and hypothalamic-pituitary-adrenal axis activity in asthmatic adults with depression.

OBJECTIVE: To investigate the features of airway inflammation and hypothalamic-pituitary-adrenal axis (HPAA) activity in patients with asthma accompanied by depression. METHODS: Adult asthmatics were recruited and enrolled into one of the two groups based on scores on the Hamilton Depression Rating Scale (HAMD): asthmatics with depression (HAMD score ≥8, n = 23), and asthmatics without depression (HAMD score <8, n = 41). In addition, 27 healthy individuals and 21 adults with depression only were enrolled as controls. Induced sputum and blood samples were collected for measurement of cytokines and other inflammatory factors. The diurnal rhythm profiles of salivary cortisol and other hormones were obtained for assessment of the HPAA activity. RESULTS: For the group of asthmatics with depression, the mean HAMD score was 19.0, and for the group of asthmatics without depression, the HAMD score averaged 4.9(p < .001). Serum and sputum tumor necrosis factor alpha (TNF-α) were significantly higher in asthmatics with depression than those in the other groups (p < .05) while serum interferon-gamma (IFN-γ) was lower in asthmatics with depression than that in the other groups (p < .05). Twenty-four-hour urinary cortisol, salivary cortisol at 8 a.m. and 4 p.m. were lower in asthmatics with depression compared to other groups (p < .05). CONCLUSIONS: As compared to healthy individuals and those with asthma or depression alone, individuals with comorbid depression and asthma showed the highest level of pro-inflammatory cytokines and the lowest level of anti-inflammatory cytokines and cortisol. These observations may serve as a valuable reference for diagnosis and clinic therapies of depression in asthmatics.

[DNA extraction from bones and teeth using AutoMate Express forensic DNA extraction system].

OBJECTIVE: To explore a new method in order to extract DNA from bones and teeth automatically. METHODS: Samples of 33 bones and 15 teeth were acquired by freeze-mill method and manual method, respectively. DNA materials were extracted and quantified from the triturated samples by AutoMate Express forensic DNA extraction system. RESULTS: DNA extraction from bones and teeth were completed in 3 hours using the AutoMate Express forensic DNA extraction system. There was no statistical difference between the two methods in the DNA concentration of bones. Both bones and teeth got the good STR typing by freeze-mill method, and the DNA concentration of teeth was higher than those by manual method. CONCLUSION: AutoMate Express forensic DNA extraction system is a new method to extract DNA from bones and teeth, which can be applied in forensic practice.

Effects of microplastics on the growth, photosynthetic efficiency and nutrient composition in freshwater algae Chlorella vulgaris Beij.

Microplastics, plastic particles and fragments smaller than 5 mm are ubiquitous in various aquatic environments, but the hazards of microplastics with different particle sizes, concentrations and materials are not well understood. This study investigated the toxicity of polyethylene microplastics (PE-MPs) with different concentrations and particle sizes or polystyrene microplastics (PS-MPs) on freshwater algae Chlorella vulgaris Beij (C. vulgaris) for 11 days. Results indicated that the growth, colony formation, photosynthetic pigment contents and soluble intracellular polysaccharides were unaffected, whereas the photosynthetic efficiency and the total soluble protein (TSP) contents were remarkably decreased at 11 d with the increased concentration of PE-MP exposure. The growth, photosynthetic efficiency, soluble intracellular polysaccharides and TSP contents were unaffected after exposure to PE-MPs with different particle sizes or PS-MPs. By contrast, the colony formation and photosynthetic pigment contents were remarkably decreased after exposure to PS-MPs compared with the control or PE-MPs with the same particle size. The C. vulgaris colonization on microplastics was proven by scanning electron microscopy, indicating that the adsorption effects were the main harmful pathways of different microplastics to algal. Our results suggested that microplastics have limited harmful effects on algae, mainly in adsorption and shading.

[Prolonged duration of the routine pegylated-interferon alfa-2a therapy produces superior virological response in HBeAg-positive chronic hepatitis B patients: a single-center cohort study].

OBJECTIVE: Hepatitis B e antigen (HBeAg) seroconversion and/or hepatitis B surface antigen (HBsAg) clearance are considered as good prognostic indicators of treatment outcome in HBeAg-positive chronic hepatitis B (CHB) patients. While a sustained virological response (SVR) can be achieved by a finite 48-week course of pegylated-interferon alfa-2a (Peg-IFNalpha-2a), it has been suggested that longer-term treatment can improve the rate of SVR. Therefore, the aim of this study was to compare the effects of prolonged and routine Peg-IFNa-2a therapy in patients with HBeAg-positive CHB. METHODS: Eighty-six consecutive patients diagnosed with HBeAg-positive CHB at our hospital between September 2006 and October 2009 were enrolled in the study. The patients were randomly assigned to receive Peg-IFNa-2a (180 mug once weekly) for either 48 weeks (routine therapy group, n = 53) or 72 weeks (prolonged therapy group, n = 33). Serum samples were collected from each patient every three months until the end of the 24-week follow-up, and standard viral and biochemical tests were carried out. Relapse was defined as HBV DNA concentrations more than 105 copies/mL or an HBeAg-positive test at the end of the 24-week follow-up. Chi-squared test and the t-test were used to determine the significance of intergroup differences. Logistic regression analysis was employed to determine the correlation of outcome parameters to treatment duration, expressed as odds ratio (OR) with 95% confidence interval (CI). RESULTS: The two treatment groups were similar at baseline (pre-treatment) in demographic data, sex ratio, age, alanine aminotransferase (ALT) level, HBV DNA load, and semi-quantitative level of HBeAg (s/co) (all, P more than 0.05). At the end of the 24-week follow-up, there were significant differences between the 48-week treatment group and the 72-week treatment group in patients with HBV DNA negativity (62.3% vs. 97.0%, x2 = 13.273, P = 0.000), HBeAg seroconversion (39.6% vs. 57.6%, x2 = 6.765, P = 0.009), HBsAg clearance (15.1% vs. 36.4%, x2 = 5.155, P = 0.023), and relapse (58.5% vs. 33.3%, x2 = 6.713, P = 0.010). Logistic regression analysis indicated that therapy duration was correlated to HBeAg clearance (OR = 3.702, 95% CI: 1.225 to 11.188) and male sex (OR = 3.005, 95% CI: 1.038 to 8.696) but not to HBeAg level at baseline (OR = 0.999, 95% CI: 0.998 to 1.000) or age (OR = 0.902, 95% CI: 0.839 to 0.970). CONCLUSION: In this single-center cohort study, superior therapeutic benefit was achieved by extending the Peg-IFNa-2a therapy out to 72 weeks for patients with HBeAg-positive CHB. The prolonged duration therapy produced a higher HBsAg loss ratio, HBeAg seroconversion ratio, HBV DNA negativity ratio, and a lower relapse ratio. Furthermore, HBeAg clearance was positively correlated with duration and male sex.

Corrigendum to "Scaffolds of bioactive glass (Bioglass®) combined with recombinant human bone morphogenetic protein -9 (rhBMP-9) for tooth extraction site preservation" [Heliyon 8 (1) (January 2022) e08796].

[This corrects the article DOI: 10.1016/j.heliyon.2022.e08796.].

The effects of short-term and long-term air pollution exposure on meibomian gland dysfunction.

We aim to assess the effects of different air pollutants on meibomian gland dysfunction (MGD). As a prospective multicenter study, 864 patients were recruited from four different regions (i.e., coal, oil, steel, and living). The oil region had a significantly lower temperature and higher O3 and SO2 concentrations than other regions. Notably, participants in oil region presented with more frequent and serious MGD signs and higher cytokine levels (median interleukin 6 [IL-6] in oil: 2.66, steel: 0.96, coal: 0.38, living: 0.56; IL-8 in oil: 117.52, steel: 46.94, coal: 26.89, living: 33; vascular endothelial growth factor [VEGF] in oil: 25.09, steel: 14.02, coal: 14.02, living: 28.47). The short-term fluctuations of cytokine levels were associated with the changes in gas levels (PM2.5 and IL-8: ß = 0.016 [0.004-0.029]; O3 and IL-6: ß = 0.576 [0.386-0.702]; O3 and IL-8: ß = 0.479 [0.369-0.890]; SO2 and VEGF: ß = 0.021 [0.001-0.047]). After long-term exposure, lid margin neovascularization (r = 0.402), meibomian gland (MG) expression (r = 0.377), MG secretion (r = 0.303), MG loss (r = 0.404), and tear meniscus height (r = - 0.345) were moderately correlated with air quality index (AQI). Individuals in oil region had more serious MGD signs and higher cytokine levels. MGD is susceptible to long-term exposure to high AQI.

Stretch-inducible expression of connective tissue growth factor (CTGF) in human osteoblasts-like cells is mediated by PI3K-JNK pathway.

To explore the possible role for connective tissue growth factor (CTGF) during tooth movement, we evaluated CTGF gene and protein expression in MG-63 cells subjected to cyclic stretch. Cyclic stretch caused a time-dependent increase in CTGF mRNA and protein levels.Inhibition of p38 MAP kinase or ERK activation did not affect cyclic stretch-induced CTGF expression. Specific inhibitors of PI3K suppressed stretch -induced CTGF expression in a time-dependent manner. cyclic stretch activated JNK and ERK, but not p38 MAP kinase in osteoblast-like cells. PI3K inhibitors suppressed cyclic stretch-induced JNK, but not p38 MAP kinase activation. Finally, SP600125, a Specific Inhibitor of JNK, suppressed stretch -induced CTGF Expression. These results suggest that stretch-induced CTGF expression is mediated through the PI3K-JNK -dependent pathway, not by p38 MAP kinase and ERK pathways.

Polyhedral oligomeric silsesquioxane as a cross-linker for preparation of inorganic-organic hybrid monolithic columns.

An inorganic-organic hybrid monolithic capillary column was synthesized via thermal free radical copolymerization within the confines of a capillary using a polyhedral oligomeric silsesquioxane (POSS) reagent as the inorganic-organic hybrid cross-linker and a synthesized long carbon chain quaternary ammonium methacrylate of N-(2-(methacryloyloxy)ethyl)-dimethyloctadecylammonium bromide (MDOAB) as the organic monomer. The preparation process was as simple as pure organic polymer-based monolithic columns instead of using POSS as the nanosized inorganic-organic hybrid blocks (cross-linker) of the monolithic matrix. The pore properties and permeability could be tuned by the composition of the polymerization mixture. The characterization and evaluation results indicated that the synthesized MDOA-POSS hybrid monolith possessed the merits of organic polymer-based monoliths and silica-based monoliths with good mechanical and pH (pH 1-11) stabilities, which may be attributed to the incorporation of the rigid nanosized silica core of POSS. Column efficiencies of 223 000 and 50 000 N/m were observed in capillary electro-driven chromatography (CEC) and mu-HPLC, respectively. Peptides and standard proteins were baseline separated by this hybrid column in CEC and mu-HPLC, respectively, as well. The separation of bovine serum albumin (BSA) tryptic digest was also attempted to show its potential application in proteome analysis.

The development and evaluation of single cell suspension from wheat and barley as a model system; a first step towards functional genomics application.

BACKGROUND: The overall research objective was to develop single cell plant cultures as a model system to facilitate functional genomics of monocots, in particular wheat and barley. The essential first step towards achieving the stated objective was the development of a robust, viable single cell suspension culture from both species. RESULTS: We established growth conditions to allow routine culturing of somatic cells in 24 well microtiter plate format. Evaluation of the wheat and barley cell suspension as model cell system is a multi step process. As an initial step in the evaluation procedure we chose to study the impact of selected abiotic stress elicitors at the physiological, biochemical and molecular level. We report the results of osmotic stress imposed by NaCl and PEG. As proline is an important osmoprotectant of the cereal cells, colorimetric assay for proline detection was developed for small volumes (200 µl). We performed RT-PCR experiments to study the change in the expression of the genes encoding Δ1-pyrroline-5-carboxylate synthetase (P5CS) and Δ1-pyrroline-5-carboxylate reductase (PC5R) in response to abiotic stress. CONCLUSIONS: We found differences between the wheat and barley suspension cultures, barley being more tolerant to the applied osmotic stresses. We suggested a model to explain the obtained differences in stress tolerance between the two species. The suspension cell cultures have proven useful for determining changes in proline concentration and expression level of genes (P5CS, P5CR) under various treatments and we suggest that the cells can be used as a model host system to study gene expression and regulation in monocots.