Bortezomib inhibits C2C12 growth by inducing cell cycle arrest and apoptosis

Proteosome inhibitors such as bortezomib (BTZ) have been used to treat muscle wasting in animal models. However, direct effect of BTZ on skeletal muscle cells has not been reported. In the present study, our data showed that C2C12 cells exhibited a dose-dependent decrease in cell viability in response to increasing concentrations of BTZ. Consistent with the results of cell viability, Annexin V/PI analysis showed a significant increase in apoptosis after exposing the cells to BTZ for 24h. The detection of cleaved caspase-3 further confirmed apoptosis. The apoptosis induced by BTZ was associated with reduced expression of p-ERK. Cell cycle analysis revealed that C2C12 cells underwent G2/M cell cycle arrest when incubated with BTZ for 24h. Furthermore, BTZ inhibited formation of multinucleated myotubes. The inhibition of myotube formation was accompanied by decreased expression of Myogenin. Our data suggest that BTZ induces cell death and inhibits differentiation of C2C12 cells at clinically relevant doses.

Kinetic study and mathematical modeling of methanogenesis of acetate using pure cultures of methanogens

Kinetics of methanogenesis from acetate was studied using pure cultures of Methanosarcina barkeri and Methanosarcina mazei. Methane formation was found to be associated with cell growth. Nearly equimolar methane was produced from acetate during the methanogenic growth, and about 1.94 g of cells were formed from each mole of acetate consumed. Cell growth can be estimated from methane production. Significant substrate inhibition was found when acetate concentration was higher than 0.12 M. Among the three methanogenic strains studied, M. mazei strain S6 had the highest specific growth rate at all acetate concentrations studied and was least sensitive to environmental factors investigated (e.g., acetate concentration). The maximum specific growth rate found for strain S6 was 0.022 hr(-1) at acetic acid concentration around 7 g/L. The other two strains studied were M. barkeri strain 227 and strain MS. Growth of M. barkeri was completely inhibited at sodium acetate concentrations higher than 0.24 M. The maximum specific growth rate found for strains 227 and MS was 0.019 and 0.021 h(-1) at acetic acid concentrations of 3.6 and 6.8 g/L, respectively. A kinetic model with substrate inhibition was developed and can be used to simulate the methane formation from M. mazei strain S6 grown on acetate at 35 degrees C, pH 7.

Fiber optic chemical sensor for nitrite based on an electropolymerized cobaltporphyrin film

Fiber optic sensors for nitrite were prepared by first electrochemically depositing a film of cobalt(II) tetrakis(o-aminophenyl)porphyrin, [Co(o-NH(2))TPP], on the surface of indium(tin) oxide glass slides. Then, the slides with the immobilized porphyrin were positioned at the tip of an optical fiber bundle. The response of the sensors was based on a change in absorbance caused by the interaction between nitrite and the poly[Co(o-NH(2))TPP] film. The sensors had a detection limit of 6 x 10(-9)M nitrite. The selectivity of the sensors was determined under both separate solutions and fixed interference conditions. The sensor had a long lifetime and was reversible.

Polysaccharides from the root of Angelica sinensis promotes hematopoiesis and thrombopoiesis through the PI3K/AKT pathway

Background

Dozens of Traditional Chinese Medicine (TCM) formulas have been used for promotion of "blood production" for centuries, and we are interested in developing novel thrombopoietic medicines from these TCMs. Our previous studies have demonstrated the hematopoietic effects of DangGui BuXue Tong (DBT), a formula composed of Radix Angelicae Sinensis and Radix Astragali in animal and cellular models. As a step further to identify and characterize the active chemical components of DBT, we tested the hematopoietic and particularly, thrombopoietic effects of polysaccharide-enriched fractions from the root of Radix Angelicae Sinensis (APS) in this study.

Methods

A myelosuppression mouse model was treated with APS (10 mg/kg/day). Peripheral blood cells from APS, thrombopoietin and vehicle-treated samples were then counted at different time-points. Using the colony-forming unit (CFU) assays, we determined the effects of APS on the proliferation and differentiation of hematopoietic stem/progenitor cells and megakaryocytic lineages. Using a megakaryocytic cell line M-07e as model, we analyzed the cellular apoptosis progression with and without APS treatment by Annexin V, Mitochondrial Membrane Potential and Caspase 3 assays. Last, the anti-apoptotic effect of APS on cells treated with Ly294002, a Phosphatidylinositol 3-Kinse inhibitor (PI3K) was also tested.

Results

In animal models, APS significantly enhanced not only the recovery of platelets, other blood cells and their progenitor cells, but also the formation of Colony Forming Unit (CFU). In M-07e cells, we observed the anti-apoptotic effect of APS. Treatment by Ly294002 alone increased the percentage of cells undergoing apoptosis. However, addition of APS to Ly294002-treated cells significantly reduced the percentage of cells undergoing apoptosis.

Conclusions

APS promotes hematopoiesis and thrombopoiesis in the mouse model. This effect likely resulted from the anti-apoptosis activity of APS and is likely to involve the PI3K/AKT pathway.

Kinetics of Homoacetic Fermentation of Lactate by Clostridium formicoaceticum

Clostridium formicoaceticum homofermentatively converted lactate to acetate at mesophilic temperatures (30 to 42 degrees C) and at pHs between 6.6 and 9.6. The production of acetate was found to be growth associated. Approximately 0.96 g of acetic acid and 0.066 g of cells were formed from each gram of lactic acid consumed at 37 degrees C. The concentration of the substrate (lactate) had little or no effect on the growth rate; however, the fermentation was inhibited by acetic acid. The bacterium grew at an optimal pH of 7.6 and an optimal temperature of 37 degrees C. Small amounts of bicarbonate were stimulatory to bacterial growth. Bacterial growth was enhanced, however, by the use of higher concentrations of bicarbonate in the media, only because higher buffer capacities were obtained and proper medium pH could be maintained for growth. Based on its ability to convert lactate to acetate, this homoacetic bacterium may be important in the anaerobic methanogenic process when lactate is a major intermediary metabolite.

Propionic acid fermentation of lactose by Propionibacterium acidipropionici: effects of pH

Batch propionic acid fermentation of lactose by Propionibacterium acidipropionici were studied at various pH values ranging from 4.5 to 7.12. The optimum pH range for cell growth was between 6.0 and 7.1, where the specific growth rate was approximately 0.23 h(-1). The specific growth rate decreased with the pH in the acids have been identified as the two major fermentation products from lactose. The production of propionic acid was both growth and nongrowth associated, while acetic acid formation was closely associated with cell growth. The propionic acid yield increased with decreasing pH; It changed from approximately 33% (w/w) at pH 6.1-7.1 to approximately 63% at pH 4.5-5.0. In contrast, the acetic acid yield was not significantly affected by the pH; it remained within the range of 9%-12% at all pH values. Significant amounts of succinic and pyruvic acids were also formed during propionic acid fermentation of lactose. However, pyruvic acid was reconsumed and disappeared toward the end of the fermentation. The succinic acid yield generally decreased with the pH, from a high value of 17% at pH 7.0 to a low 8% at pH 5.0 Effects of growth nutrients present in yeast ex-tract on the fermentation were also studied. In general, the same trend of pH effects was found for fermentations with media containing 5 to 10 g/L yeast extract. However, More growth nutrients would be required for fermentations to be carried out efficienytly at acidic pH levels.

Role of macrophage migration inhibitory factor in influenza H5N1 virus pneumonia

The severe and often fatal disease in humans and birds caused by H5N1 influenza viruses has been attributed to aberrant pulmonary inflammatory responses. We investigated the role of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and a pivotal regulator of innate immunity, in H5N1 influenza virus pneumonia in murine model. We found increased MIF mRNA levels in the lungs and MIF protein levels in the serum of infected mice. Although the inhibition of MIF action by isoxazolone-1 (ISO-1) did not render mice more resistant to the lethality of infection, it caused a significant reduction in pulmonary inflammatory cytokines interleukin-1 beta (IL-1beta), IL-6 and tumor necrosis factor alpha (TNF-alphalfa) and chemokine interferon-inducible protein-10 (IP-10). These results indicate the involvement of MIF in inflammatory responses to H5N1 influenza virus infections by induction of pulmonary inflammatory cytokines and chemokines, and suggest that pharmacotherapeutic approaches targeting MIF may hold promise for the treatment of H5N1 influenza virus pneumonia.

Effects of temperature on lactose hydrolysis by immobilized beta-galactosidase in plug-flow reactor

The hydrolysis of lactose using immobilized beta-galactosidase (from Aspergillus niger) on phenol-formaldehyde resin was studied at temperatures between 8 and 60 degrees C and initial lactose concentrations ranging from 2.5 to 20.0%. A model involving enzyme-galactose complex similar to Michaelis-Menten kinetics with competitive product (galactose) inhibition is suitable to describe the lactose hydrolysis reaction. A small degree of lack of fit between the model and the data was found to be due to the formation of oligosaccharides. Thermal deactivation of lactase follows first-order reaction mechanism. The effect of temperature on the reaction and the deactivation rate constants follows the Arrhenius relationship. The Oligosaccharide formation was not significantly affected by the temperature when the initial lactose concentration was 5%. A design equation for the plug-flow immobilized lactase reactor was developed from the reaction and the deactivation kinetics and was used to find the optimal operating temperature. The optimal temperature was found to be dependent on the operating time but not on the lactose concentration or the conversion. The optimal operating temperature is 60 degrees C when operating time is short but is close to 35 degrees C for a long operating time. A preliminary economic analysis indicates that the optimal operating temperature is 43, 38.5, and 33 degrees C when the operating time is 300 days, 1000 days, and infinity, respectively.

Effects of pH and acetic acid on homoacetic fermentation of lactate by Clostridium formicoaceticum

Clostridium formicoaceticum homofermentatively converts lactate to acetate at 37 degrees C and pH 6.6-9.6. However, this fermentation is strongly inhibited by acetic acid at acidic pH. The specific growth rate of this organism decreased from a maximum at pH 7.6 to zero at pH 6.6. This inhibition effect was found to be attributed to both H(+) and undissociated acetic acid. At pH values below 7.6, the H(+) inhibited the fermentation following non-competitive inhibition kinetics. The acetic acid inhibition was found to be stronger at a lower medium pH. At pH 6.45-6.8, cell growth was found to be primarily limited by a maximum undissociated acetic acid concentration of 0.358 g/L (6mM). This indicates that the undissociated acid, not the dissociated acid, is the major acid inhibitor. At pH 7.6 or higher, this organism could tolerate acetate concentrations of higher than 0.8M, but salt (Na(+)) became a strong inhibitor at concentrations of higher than 0.4M. Acetic acid inhibition also can be represented by noncompetitive inhibition kinetics. A mathematical model for this homoacetic fermentation was also developed. This model can be used to simulate batch fermentation at any pH between 6.9 and 7.6.

A novel recycle batch immobilized cell bioreactor for propionate production from whey lactose

Recycle batch fermentations using immobilized cells of Propionibacterium acidipropionici were studied for propionate production from whey permeate, de-lactose whey permeate, and acid whey. Cells were immobilized in a spirally wound fibrous sheet packed in a 0.5-L column reactor, which was connected to a 5-L stirred tank batch fermentor with recirculation. The immobilized cells bioreactor served as a breeder for these recycle batch fermentations. High fermentation rates and conversions were obtained with these whey media without nutrient supplementation. It took approximately 55 h to ferment whey permeate containing approximately 45 g/L lactose to approximately 20 g/L propionic acid. Higher propionate concentrations can be produced with various concentrated whey media containing more lactose. The highest propionic acid concentration obtained with the recycle batch reactor was 65 g/L, which is much higher than the normal maximum concentration of 35 to 45 g/L reported in the literature. The volumetric productivity ranged from 0.22 g/L x h to 0.47 g/L x h, depending on the propionate concentration and whey medium used. The corresponding specific cell productivity was 0.033 to 0.07 g/L x g cell. The productivity increased to 0.68 g/L x h when whey permeate was supplemented with 1% (w/v) yeast extract. Compared with conventional batch fermentation, the recycle batch fermentation with the immobilized cell bioreactor allows faster fermentation, produces a higher concentration of product, and can be run continually without significant downtime. The process also produced similar fermentation results with nonsterile whey media.

Demonstration of high-energy 2 omega (526.5 nm) operation on the National Ignition Facility Laser System

A single beamline of the National Ignition Facility (NIF) has been operated at a wavelength of 526.5 nm (2 omega) by frequency converting the fundamental 1053 nm (1 omega) wavelength with an 18.2 mm thick type-I potassium dihydrogen phosphate (KDP) second-harmonic generator (SHG) crystal. Second-harmonic energies of up to 17.9 kJ were measured at the final optics focal plane with a conversion efficiency of 82%. For a similarly configured 192-beam NIF, this scales to a total 2 omega energy of 3.4 MJ full NIF equivalent (FNE).

National Ignition Facility laser performance status

The National Ignition Facility (NIF) is the world's largest laser system. It contains a 192 beam neodymium glass laser that is designed to deliver 1.8 MJ at 500 TW at 351 nm in order to achieve energy gain (ignition) in a deuterium-tritium nuclear fusion target. To meet this goal, laser design criteria include the ability to generate pulses of up to 1.8 MJ total energy, with peak power of 500 TW and temporal pulse shapes spanning 2 orders of magnitude at the third harmonic (351 nm or 3omega) of the laser wavelength. The focal-spot fluence distribution of these pulses is carefully controlled, through a combination of special optics in the 1omega (1053 nm) portion of the laser (continuous phase plates), smoothing by spectral dispersion, and the overlapping of multiple beams with orthogonal polarization (polarization smoothing). We report performance qualification tests of the first eight beams of the NIF laser. Measurements are reported at both 1omega and 3omega, both with and without focal-spot conditioning. When scaled to full 192 beam operation, these results demonstrate, to the best of our knowledge for the first time, that the NIF will meet its laser performance design criteria, and that the NIF can simultaneously meet the temporal pulse shaping, focal-spot conditioning, and peak power requirements for two candidate indirect drive ignition designs.

Separation of benzene, toluene, ethylbenzene, and xylenes by micellar electrokinetic capillary chromatography

The use of sodium dodecyl sulfate, urea, beta-cyclodextrin, and methanol as additives to the electrophoretic medium containing a Na2HPO4-boric acid buffer in the micellar electrokinetic capillary chromatography of benzene, toluene, ethylbenzene, and three isomers of xylene (collectively known as BTEX) was investigated. The results showed that with the addition of sodium dodecyl sulfate only, higher selectivity and sensitivity and shorter migration time could be achieved, which consequently resulted in better separation of BTEX studied. For this buffer system, good linearity (R2>0.99) was found over the range of 5 to 500 microg ml(-1) for individual BTEX compound and separation time of less than 5 min for BTEX was possible.

Boerhaave's syndrome presenting as a right-sided pleural effusion

INTRODUCTION

Boerhaave's syndrome is an uncommon condition where there is oesophageal rupture following forceful vomiting, subsequent mediastinitis and is associated with high mortality and morbidity in the absence of therapy. We present a case of Boerhaave's syndrome in a 79-year-old woman who developed a right-sided effusion, an unusual presentation.

CLINICAL PICTURE

A 79-year-old woman developed a right-sided empyema and mediastinitis after a bout of repeated vomiting. Gastrograffin swallows and oesophago-gastroduodenoscopy confirmed oesophageal rupture.

TREATMENT

The patient was treated with antibiotics and a tube thoracostomy. An open thoracotomy, oesophagostomy and thoracic window was subsequently performed.

OUTCOME

The oesophageal rupture was contained but patient died from postoperative complications.

CONCLUSIONS

Physicians should have a high index of suspicion of oesophageal rupture when patients present with Meckler's triad of symptoms and especially when pleural fluid cultures grow bacteria native to the gastrointestinal tract.

Vascular endothelial growth factor isoforms display distinct activities in promoting tumor angiogenesis at different anatomic sites

The gene for the major angiogenic factor, vascular endothelial growth factor (VEGF), encodes several spliced isoforms. We reported previously that overexpression of two VEGF isoforms, VEGF(121) and VEGF(165), by human glioma U87 MG cells induced tumor-associated intracerebral hemorrhage, whereas expression of a third form, VEGF(189), did not cause vessel rupture. Here, we test whether these VEGF isoforms have distinct activities for enhancing vascularization and growth of gliomas in mice. U87 MG cells that overexpressed VEGF(165) or VEGF(189) grew more rapidly than the parental cells in both s.c. and intracranial (i.c.) locations. However, cells that overexpressed VEGF(121) only showed enhancement of i.c. tumor growth but had a minimal effect on s.c. glioma progression. At both anatomical sties, VEGF(165) and VEGF(189) strongly augmented neovascularization, whereas VEGF(121) only increased vessel density in brain tumors. In each type of glioma, expression of VEGF receptors -1 and -2 largely phenocopied the tumor vasculature, because increased VEGF/VEGF receptor-activated microvessel densities were strongly correlated with the angiogenicity and tumorigenicity elicited by the VEGF isoforms at both anatomical sites. One notable difference between the sites was the expression of vitronectin, a prototypic ligand of alpha(v)beta(3) and alpha(v)beta(5) integrins, detected in i.c. but not in s.c., gliomas. Endothelial cell migration stimulated by VEGF(121) was potentiated by vitronectin to a greater extent than that stimulated by VEGF(165). This data demonstrates that VEGF isoforms have distinct activities at different anatomical sites and suggest that the microenvironment of different tissues affects the function of VEGF isoforms.

Antibacterial, antitumor and hemolytic activities of alpha-helical antibiotic peptide, P18 and its analogs

The alpha-helical antibiotic peptide (P18: KWKLFKKIPKFLHLAKKF-NH2) designed from the cecropin A(1-8)-magainin 2 (1-12) hybrid displayed strong bactericidal and tumoricidal activity without inducing hemolysis. The effect of the Pro9 residue at central position of P18 on cell selectivity was investigated by Pro9 --> Leu or Pro9 --> Ser substitution. Either substitution markedly reduced the antibacterial activity of P18 and increased hemolysis, although it did not significantly affect cytotoxicity against human transformed tumor and normal fibroblast cells. These results suggest that a proline kink in alpha-helical antibiotic peptide P18 serves as a hinge region to facilitate ion channel formation on bacterial cell membranes and thus plays an important role in providing high selectivity against bacterial cells. Furthermore, to investigate the structure-antibiotic activity relationships of P18, a series of N- or C-terminal deletion and substitution analogs of P18 were synthesized. The C-terminal region of P18 was related to its antibiotic activity and alpha-helical conformation on lipid membranes rather than N-terminal one. Higher alpha-helicity of the peptides was involved in the hemolytic and antitumor activity rather than antibacterial activity. Except for [L9]-P18 and [S9]-P18, all the designed peptides containing a Pro residue showed potent antibacterial activity, although they did not induce a cytolytic effect against human erythrocyte and normal fibroblast cells at the concentration required to kill bacteria. In particular, P18 and some analogs (N-1, N-2, N-3, N-3L and N-4L) with potent bactericidal and tumoricidal activity and little or no normal cell toxicity may serve as an attractive candidate for the development of novel anti-infective or antitumor agents.

Oxygen tension influences proliferation and differentiation in a tissue-engineered model of placental trophoblast-like cells

A considerable oxygen gradient exists in vivo, which exerts regulatory effects on tissue development and function. The objective of this study was to evaluate the feasibility of controlling cell proliferation and differentiation by regulating oxygen tension in a tissue-engineered bioreactor model. The effects of oxygen tension on proliferation and differentiation of first-trimester human trophoblast cells (known as ED(27) cells) were studied in a fiber-bed perfusion bioreactor system in which cells were grown in polyethylene terephthalate (PET) nonwoven fibrous matrix. By varying the oxygen tension between 2% and 20%, differential responses of trophoblasts in their proliferation and differentiation activities were observed. There was no significant difference in the rates of glucose consumption and lactate production, and lactate dehydrogenase (LDH) level in the culture media for both 2% and 20% oxygen tension cultures, indicating that cell metabolic activities were not limited by low oxygen tension. However, 2% oxygen stimulated cell proliferation but impeded the secretion of a functional hormone, 17beta-estradiol. In contrast, 20% oxygen tension reduced cell proliferation, but yielded higher hormone secretion. A step change in oxygen tension from 2% to 20% caused cells in the bioreactor to increase 17beta-estradiol secretion and shifted cell cycle from proliferation to differentiation, which were verified with the expression levels of cyclin B1 and p27(kip1). However, no significant response to a change from 6% to 20% oxygen tension was observed. It is concluded that changes in oxygen tension can be an effective strategy to control cell cycle and long-term tissue development. This work also demonstrated the important role of oxygen tension in regulating placental trophoblast tissue development and the feasibility of using the bioreactor under well-controlled physiological environment for tissue engineering applications.

Three-dimensional cell-scaffold constructs promote efficient gene transfection: implications for cell-based gene therapy

To date, introduction of gene-modified cells in vivo is still a critical limitation for cell-based gene therapy. In this study, based on tissue engineering techniques, we developed a three-dimensional (3-D) transfection system to be cell-based gene delivery vehicle. Human trophoblast-like ED(27) and fibroblastic NIH3T3 cells were used as model cell lines. Cells were seeded onto PET fibrous matrices and plated on polyethylene terephathalate (PET) films as 2-D transfection control. The cell-matrices and cell-films were transfected with pCMV-betagal and pEGFP (green fluorescent protein) reporter gene vectors using LipofectAmine reagent. Gene expression on 3-D versus 2-D growth surface were investigated. The effects of seeding method, seeding density, porosity of the PET matrix, and culturing time of the cell-matrix complex on cDNA transfection and expression in the 3-D cell-matrix complex were also investigated. The beta-gal assay and GFP detection showed that 3-D transfection promoted a higher gene expression level and longer expression time as compared to 2-D transfection. There existed an optimal initial cell seeding density for gene transfection of 3-D cell-matrix complex. Cells seeded on PET matrices with a lower porosity ( approximately 87%) had higher gene expression activities than cells in the matrices with a higher porosity ( approximately 90%). Also, Higher gene expression levels of beta-gal were obtained for the more uniformly seeded matrices that were seeded with a depth-filtration method. The results from this study demonstrate the potential utility of cells seeded onto 3-D fibrous matrices as cell-based gene delivery vehicle for in vitro study of gene expression or in vivo gene therapy.

Effects of filtration seeding on cell density, spatial distribution, and proliferation in nonwoven fibrous matrices

The cell seeding density and spatial distribution in a 3-D scaffold are critical to the morphogenetic development of an engineered tissue. A dynamic depth-filtration seeding method was developed to improve the initial cell seeding density and spatial distribution in 3-D nonwoven fibrous matrices commonly used as tissue scaffolds. In this work, trophoblast-like ED27 cells were seeded in poly(ethylene terephthalate) (PET) matrices with various porosities (0.85-0.93). The effects of the initial concentration of cells in the suspension used to seed the PET matrix and the pore size of the matrix on the resulting seeding density and subsequent cell proliferation and tissue development were studied. Compared to the conventional static seeding method, the dynamic depth-filtration seeding method gave a significantly higher initial seeding density (2-4 x 10(7) vs 4 x 10(6) cells/cm3), more uniform cell distribution, and a higher final cell density in the tissue scaffold. The more uniform initial cell spatial distribution from the filtration seeding method also led to more cells in S phase and a prolonged proliferation period. However, both uniform spatial cell distribution and the pore size of the matrices are important to cell proliferation and morphological development in the seeded tissue scaffold. Large-pore matrices led to the formation of cell aggregates and thus might reduce cell proliferation. The dynamic depth-filtration seeding method is better in providing a higher initial seeding density and more uniform cell distribution and is easier to apply to large tissue scaffolds. A depth-filtration model was also developed and can be used to simulate the seeding process and to predict the maximum initial seeding densities in matrices with different porosities.

Structure-activity analysis of SMAP-29, a sheep leukocytes-derived antimicrobial peptide

SAMP-29 is a cathelecidin-derived antimicrobial peptide deduced from sheep myeloid mRNA. To elucidate the structural-activity relationship of SMAP-29, several analogues were synthesized and their antibiotic activity was investigated. Compared to parental SMAP-29, SMAP-29(1-17) and [K(22,25,27)]-SMAP-29 retained relatively effective antimicrobial activity (MIC: 1.0-8.0 microM), but resulted in a complete loss of hemolytic activity. Pro-19 --> Ala substitution ([A19]-SMAP-29) in SMAP-29 induced a significant reduction in antibacterial activity. These results suggested that the N-terminal amphipathic alpha-helical region and the C-terminal hydrophobic region of SMAP-29 are responsible for antimicrobial activity and hemolytic activity, respectively, and the central Pro-19 in SMAP-29 plays a critical role in showing improved antibacterial activity. In particular, [K(2,7,13)]-SMAP-29(1-17) showed potent antimicrobial activity under high salt conditions without hemolytic activity. Thus, this short peptide could serve as an attractive candidate for the development of therapeutic antimicrobial drugs. Structural analysis by circular dichroism suggested that SMAP-29 seems to adopt a helix-bend/turn-extended random conformation.

Human cord cell hematopoiesis in three-dimensional nonwoven fibrous matrices: in vitro simulation of the marrow microenvironment

Current hematopoietic culture systems mainly utilize two-dimensional devices with limited ability to promote self-renewal of early progenitors. In vivo-like three-dimensional (3-D) culture environments might be conducive to regulating stem cell proliferation and differentiation similar to in vivo hematopoiesis. The few 3-D cultures reported in the literature either produced few progenitors or provided little information about microenvironment. In this study, we constructed a 3-D hematopoietic microenvironment composed of nonwoven matrix and human cord blood (CB) cells to simulate the marrow microenvironment and expand cord progenitors. Nonwoven polyethylene terephthalate (PET) fabric with defined microstructure was used as the 3-D scaffold and the PET surface was modified by hydrolysis to improve cell adhesion. Different cell organizations were formed in a 3-D matrix in a developmental manner, from individual cells and cells bridging between fibers to large cell aggregates. Both stromal and hematopoietic cells were distributed spatially within the scaffold. Compared to two-dimensional (2-D) CD34(+) cell culture, 3-D culture produced 30-100% higher total cells and progenitors without exogenous cytokines. With thrombopoietin and flt-3/flk-2 ligand, it supported two- to three-fold higher total cell number (62.1- vs. 24.6-fold), CD34(+) cell number (6.8- vs. 2.8-fold) and colony-forming unit (CFU) number for 7-9 weeks (n = 6), indicating a hematopoiesis pathway that promoted progenitor production. Culture in 3-D nonwoven matrices enhanced cell-cell and cell-matrix interactions and allowed 3-D distribution of stromal and hematopoietic cells. The formation of cell aggregates and higher progenitor content indicated that the spatial microenvironment in 3-D culture played an important role in promoting hematopoiesis. This 3-D culture system can be used as an in vitro model to study stem cell or progenitor behavior, and to achieve sustained progenitor expansion.

Genetic diversity among different clones of the gynogenetic silver crucian carp, Carassius auratus gibelio, revealed by transferrin and isozyme markers

Genetic diversity among four clones (A, D, E, F) of gynogenetic silver crucian carp was studied using transferrin and isozymes in the blood as markers. Of the five proteins investigated, three (transferrin, esterase and superoxide dismutase) indicated polymorphism and eight polymorphic loci were detected. These loci were probably encoded by codominant alleles and their inheritance patterns were analyzed. Intraclonal homogeneity and interclonal heterogeneity were observed in these clones, which allowed us to infer the clonal nature and evolutionary relationship between them. Clonal diversity in this population of silver crucian carp in China was also compared with data reported from gynogenetic crucian carp in Germany.

Thermal compression and characterization of three-dimensional nonwoven PET matrices as tissue engineering scaffolds

Nonwoven fibrous matrices have been widely used as scaffolds in tissue engineering, and modification of microstructure of these matrices is needed to organize cells in three-dimensional space with spatially balanced proliferation and differentiation required for functional tissue development. The method of thermal compression of nonwoven polyethylene terephthalate (PET) fabrics was developed and key parameters of temperature, pressure, and compression duration were evaluated in this study. The permanent deformation was obtained at elevated temperature under pressure and the viscoelastic compressional behaviors were observed, characterized by a distinct apparent modulus change in glass transition temperature region. A liquid extrusion method was further employed to analyze both pore size and its distribution for matrices with porosity ranging from 84 to 93%. It is also found that a more uniformly distributed pore size was resulted from thermal compression and the isotropic nature of nonwoven fabrics was preserved because of the proportional reduction of the pore by compression. The thermally compressed fabric matrices with two different pore sizes (15 and 20 microm in pore radius) were used to culture human trophoblast ED27 and NIH 3T3 cells. It was found that cells cultured in the different pore-size PET matrices had different cell spatial organization and proliferation rates. The smaller pores in the matrix allowed cells to spread better and proliferate faster, while cells in the larger pores tended to form large aggregates and had lower proliferation rate. The thermal compression technique also can be applied to other synthetic fibrous matrices including biodegradable polymers used in tissue engineering to modify the microstructure according to their viscoelastic properties.

Therapeutic zygapophyseal joint injections for headaches emanating from the C2-3 joint

OBJECTIVE

To report our experience using fluoroscopically guided therapeutic intra-articular C2-3 zygapophyseal joint injections in patients with chronic headaches after a whiplash event.

DESIGN

Restrospective study (n = 18 patients) with independent clinical review. Each patient experienced persistent daily headache symptoms which failed to improve after at least 3 mo of physical therapy, activity restriction, and the use of oral analgesics. Each patient demonstrated initially a positive response to a diagnostic intra-articular C2-3 joint injection. Data collection and analysis were performed by an independent clinical reviewer. Outcome measures included headache frequency, medication usage, symptom response to medication, and employment status.

RESULTS

Patients' symptom duration before diagnostic injection averaged 34 mo. Follow-up data collection transpired at an average of 19 mo after the final therapeutic injection. In 61% of patients, fewer than three headaches were experienced each week; these headaches were relieved with the use of oral analgesics.

CONCLUSIONS

Although the inherent limitations of this study preclude a definitive statement regarding the efficacy of C2-3 injections, these initial findings suggest that therapeutic intra-articular zygapophyseal joint injections are effective in the treatment of headaches emanating from the C2-3 joint after a whiplash event. Future controlled, prospective studies are necessary to clarify the role of such injections in this challenging patient population.