The pivotal role of Bifida Ferment Lysate on reinforcing the skin barrier function and maintaining homeostasis of skin defenses in vitro

BACKGROUND

The semiactive or inactive probiotics or their extracts used in dermatology have interesting properties to ameliorate signs of irritated skin and enhance the skin barrier. Bifidobacterium, as the most common probiotics, which has been found to be effective in reducing acne and improving the skin barrier function of atopic dermatitis. Bifida Ferment Lysate (BFL) can be obtained from Bifidobacterium by fermentation and extraction.

PURPOSE

In this study, we investigated the effect of a topically used BFL on the skin using in vitro evaluation methods.

RESULTS

The results showed that upregulation of skin physical barrier gene (FLG, LOR, IVL, TGM1, and AQP3) and antimicrobial peptide gene (CAMP and hBD-2) in HaCaT cells by BFL might be responsible for skin barrier resistance. In addition, BFL had strong antioxidant properties representing a dose-dependent increasing of the scavenging capacity of DPPH, ABTS, hydroxyl, and superoxide radicals. BFL treatment also fundamentally inhibited the intracellular ROS and MDA production and improved the activities of antioxidant enzymes (CAT and GSH-Px) in H2 O2 -stimulated HaCaT cells. As a good immunomodulatory factor, BFL efficiently decreased the secretion of IL-8 and TNF-α cytokines, and COX-2 mRNA expression in LPS-induced THP-1 macrophages.

CONCLUSION

BFL can strengthen the skin barrier function and stimulate skin barrier resistance, to reinforce the skin against oxidative stress and inflammatory stimuli.

Genome-directed discovery of antiproliferative bafilomycins from a deepsea-derived Streptomyces samsunensis

Genomic bioinformatics analysis identified a bafilomycin biosynthetic gene cluster (named bfl) in the deepsea-derived S. samsunensis OUCT16-12, from which two new (1 and 2, named bafilomycins R and S) along with four known (3-6) bafilomycins were targetly obtained. The structure of 3 was clearly identified for the first time, thus named bafilomycin T herein. Differ from the fumarate substitution at C-21 of known bafilomycins, its location on C-23 is a unique feature of 1 and 2. The stereochemistry of the compounds was established based on NOE correlations, ketoreductase (KR)-types in PKS modules of bfl, and ECD calculations. Moreover, a detailed biosynthetic model of 1-6 in S. samsunensis OUCT16-12 was provided based on the gene function prediction and sequence identity. Compared with the positive control doxorubicin, 1-6 showed more potent antiproliferative activities against drug-resistant lung cancer cell line A549-Taxol, with IC50 values ranging from 0.07 μM to 1.79 μM, which arrested cell cycle in G0/G1 phase to hinder proliferation.

A Methylcellulose Microculture Assay for the In Vitro Assessment of Drug Toxicity on Granulocyte/macrophage Progenitors (CFU-GM)

In a recent prevalidation study, the use of a methylcellulose colony-forming unit-granulocyte/macrophage (CFU-GM) macroassay for two independent in vitro tests (human and murine cell based) was suggested for quantifying the potential haematotoxicity of xenobiotics. In this paper, we describe the transfer of the macroassay to a 96-well plate microassay, in which the linearity of the response was studied (both in terms of CFU-GM and optical density [OD] versus the number of cells cultured), and the inhibitory concentration (IC) values for doxorubicin, 5-fluorouracil and taxol were determined and compared with those obtained by using the original macroassay. Fresh murine bone marrow and human umbilical cord blood mononuclear cells were used as a source of myeloid progenitors. The cells were cultured in methylcellulose containing granulocyte/macrophage-colony-stimulating factor, and in the presence of increasing drug concentrations. The cloning capacity of the progenitors was measured both as the number of colonies counted manually (CFU-GM), and as OD evaluated with an automated plate reader in an MTT test. Our results show that, in the microassay, up to 20 colonies/well could be easily counted, and that this range (20 to zero) gave a regression line from which IC values were calculated, which were very close to those obtained by using the macroassay (where the range of colony numbers was from 100 to zero). The test did not give good results when the OD (instead of the colony count) was used as the endpoint, because, although a high coefficient of determination was obtained, the OD values ranged from 0.6 to zero and the IC values determined were not comparable to those obtained by manual counts. The use of the microassay dramatically reduces the quantity of methylcellulose needed, and permits hundreds of cultures to be processed in the same experiment, contributing to significant reductions in both the work involved and the cost. A further important benefit is a reduction of the amount of drug needed for testing, which is crucial for screening new molecules, when many different toxicological tests have to be carried out. The microassay is therefore a useful and reproducible tool for screening compounds (chemicals, drugs and xenobiotics) for potential haematotoxicity directly on human myeloid progenitors, and could contribute significantly to reducing the use of animals in toxicity testing.

Cationic methylcellulose derivative with serum-compatibility and endosome buffering ability for gene delivery systems

In this work, methylcellulose was employed as a template polymer with graft of polyethylenimine 0.8 kDa (PEI0.8k) for gene delivery systems. Synthesized PEI-grafted oxidized methylcellulose (MC-PEI) could condense pDNA into positively charged and nano-sized particles, which could protect pDNA from serum nuclease. The cytotoxicity of MC-PEI was minimal in both serum-free and serum condition due to the biocompatibility of methylcellulose and low cytotoxicity of PEI0.8k. MC-PEI polyplex also showed low cytotoxicity in serum condition. In serum condition, MC-PEI showed less decreased transfection efficiency than PEI25k, meaning good serum-compatibility of MC-PEI. Bafilomycin A1-treated transfection results indicate that the transfection of MC-PEI is mediated via endosomal escape by endosome buffering ability. Flow cytometry results suggest that MC-PEI polyplex could be internalized into cells and efficiently deliver pDNA to cells due to its serum-compatibility. These results demonstrate that MC-PEI possesses a potential for efficient gene delivery systems.

Arginine, soy isoflavone and hydroxypropylmethylcellulose have protective effects against obesity in broiler breeder hens fed on high-energy diets

1. The present study was undertaken to determine the effects of arginine, soy isoflavone (ISF) and hydroxypropylmethylcellulose (HPMC) on obesity in broiler breeder hens. 2. A total of 320 Cobb 500 hens, 45 weeks of age, were assigned to 64 floor pens. The experiment was conducted as a completely randomised design in a factorial arrangement (2 × 2 × 2 × 2) with 4 replicates of 5 hens in each pen. Factors included two concentrations of HPMC (0 and 1%), two concentrations of arginine (8.4 and 12 g/kg), two concentrations of ISF (zero and three times more than that present in basal diets) and two contents of energy (11.7 and 14.6 MJ/kg). Performance criteria and blood characteristics of hens were measured during the experimental period. Expression of genes involved in lipid metabolism was determined in the liver at 55 weeks of age. 3. Hens given high-energy diets showed increased BW (body weight), ovary weight and abdominal fat pad and enhanced plasma glucose, triglyceride (TG), cholesterol, haemoglobin, haematocrit and low lymphocyte percentages. The expression of malic enzyme, peroxisome proliferator-activated receptor-α (PPARα), peroxisome proliferator-activated receptor-γ (PPARγ) and inducible nitric oxide (iNOS) increased and sterol regulatory element binding protein-1c (SREBP1c) decreased with increasing energy content of diets. Arginine addition decreased TG, cholesterol and A1-c haemoglobin concentration and increased PPARα, PPARγ and iNOS expression. Inclusion of ISF and HPMC decreased BW, egg weight, plasma TG, cholesterol and increased egg production and also enhanced PPARγ and iNOS expression. Significant interactions were observed between energy concentration and ISF and HPMC on BW. 4. The results of the current study revealed that ISF, HPMC and arginine have beneficial effects on controlling the metabolism of obese broiler breeder hens and using a mix of these products minimises the harmful effects of obesity.

Statistical approach for assessing the influence of calcium silicate and HPMC on the formulation of novel alfuzosin hydrochloride mucoadhesive-floating beads as gastroretentive drug delivery systems

Multiparticulate floating drug delivery systems have proven potential as controlled-release gastroretentive drug delivery systems that avoid the "all or none" gastric emptying nature of single-unit floating dosage forms. An objective of the presence investigation was to develop calcium silicate (CaSi)/calcium alginate (Ca-Alg)/hydroxypropyl methylcellulose (HPMC) mucoadhesive-floating beads that provide time- and site-specific drug release of alfuzosin hydrochloride (Alf). Beads were prepared by simultaneous internal and external gelation method utilizing 3(2) factorial design as an experimental design; with two main factors evaluated for their influence on the prepared beads; the concentration of CaSi as floating aid (X (1)) and the percentage of HPMC as viscosity enhancer and mucoadhesive polymer (X (2)), each of them was tested in three levels. Developed formulations were evaluated for yield, entrapment efficiency, particle size, surface topography, and buoyancy. Differential scanning calorimetry, Fourier transform infrared spectroscopy, in vitro drug release, as well as in vitro mucoadhesion using rat stomach mucosal membrane were also conducted. Percentage yield and entrapment efficiency ranged from 57.03% to 78.51% and from 49.78% to 83.26%, respectively. Statistical analysis using ANOVA proved that increasing the concentration of either CaSi or HPMC significantly increased the beads yield. Both CaSi and HPMC concentrations were found to significantly affect Alf release from the beads. Additionally, higher CaSi concentration significantly increased the beads diameter while HPMC concentration showed significant positive effect on the beads mucoadhesive properties. CaSi/Ca-Alg/HPMC beads represent simple floating-mucoadhesive gastroretentive system that could be useful in chronopharmacotherapy of benign prostatic hyperplasia.

Interfacial interaction between transmembrane ocular mucins and adhesive polymers and dendrimers analyzed by surface plasmon resonance

PURPOSE

Development of the first in vitro method based on biosensor chip technology designed for probing the interfacial interaction phenomena between transmembrane ocular mucins and adhesive polymers and dendrimers intended for ophthalmic administration.

METHODS

The surface plasmon resonance (SPR) technique was used. A transmembrane ocular mucin surface was prepared on the chip surface and characterized by QCM-D (Quartz Crystal Microbalance with Dissipation) and XPS (X-ray photoelectron spectroscopy). The mucoadhesive molecules tested were: hyaluronic acid (HA), carboxymethyl cellulose (CMC), hydroxypropylmethyl cellulose (HPMC), chitosan (Ch) and polyamidoamine dendrimers (PAMAM).

RESULTS

While Ch originated interfacial interaction with ocular transmembrane mucins, for HA, CMC and HPMC, chain interdiffusion seemed to be mandatory for bioadherence at the concentrations used in ophthalmic clinical practise. Interestingly, PAMAM dendrimers developed permanent interfacial interactions with transmembrane ocular mucins whatever their surface chemical groups, showing a relevant importance of co-operative effect of these multivalent systems. Polymers developed interfacial interactions with ocular membrane-associated mucins in the following order: Ch(1 %) > G4PAMAM-NH(2)(2 %) = G4PAMAM-OH(2 %) > G3.5PAMAM-COOH(2 %)>> CMC(0.5 %) = HA(0.2 %) = HPMC(0.3 %).

CONCLUSIONS

The method proposed is useful to discern between the mucin-polymer chemical interactions at molecular scale. Results reinforce the usefulness of chitosan and dendrimers as polymers able to increase the retention time of drugs on the ocular surface and hence their bioavailability.

Transformation of actoHMM assembly confined in cell-sized liposome

To construct a simple model of a cellular system equipped with motor proteins, cell-sized giant liposomes encapsulating various amounts of actoHMM, the complexes of actin filaments (F-actin) and heavy meromyosin (HMM, an actin-related molecular motor), with a depletion reagent to mimic the crowding effect of inside of living cell, were prepared. We adapted the methodology of the spontaneous transfer of water-in-oil (W/O) droplets through a phospholipid monolayer into the bulk aqueous phase and successfully prepared stable giant liposomes encapsulating the solution with a physiological salt concentration containing the desired concentrations of actoHMM, which had been almost impossible to obtain using currently adapted methodologies such as natural swelling and electro-formation on an electrode. We then examined the effect of ATP on the cytoskeleton components confined in those cell-sized liposomes, because ATP is known to drive the sliding motion for actoHMM. We added α-hemolysin, a bacterial membrane pore-forming toxin, to the bathing solution and obtained liposomes with the protein pores embedded on the bilayer membrane to allow the transfer of ATP inside the liposomes. We show that, by the ATP supply, the actoHMM bundles inside the liposomes exhibit specific changes in spatial distribution, caused by the active sliding between F-actin and HMM. Interestingly, all F-actins localized around the inner periphery of liposomes smaller than a critical size, whereas in the bulk solution and also in larger liposomes, the actin bundles formed aster-like structures under the same conditions.

Mucoadhesive curcumin nanospheres: biological activity, adhesion to stomach mucosa and release of curcumin into the circulation

Although mucoadhesive drug carriers for the gastro-intestinal tract (GIT) have been reported, the mucoadhesive property and drug release characteristics have never been evaluated separately, whilst the adherence of the carriers to the surface of GIT has not been directly visualized. Here, a monopolymeric carrier made from ethylcellulose (EC) and a dipolymeric carrier made from a blend of methylcellulose (MC) and EC (ECMC) were easily fabricated through a self-assembling process and yielded the highest reported curcumin loading of ~48-49%. Both curcumin loaded ECMC (C-ECMC) and curcumin loaded EC (C-EC) particles showed an in vitro free radical scavenging activity and a dose-dependent in vitro cytotoxic effect towards MCF-7 human breast adenocarcinoma and HepG2 hepatoblastoma cells in tissue culture. The in vivo evaluation of their adherence to stomach mucosa and their ability to release curcumin into the circulation were carried out through quantification of curcumin levels in the stomach tissue and in blood of mice orally administered with the two spheres. Direct evidence of the adherence of the C-EC and C-ECMC particles along the mucosal epithelia of the stomach is also presented for the first time through SEM images. The mucoadhesive property of self-assembled C-EC nanoparticles is discussed.

The role of tyloses in crown hydraulic failure of mature walnut trees afflicted by apoplexy disorder

In the Central Valley of California, mature walnut trees afflicted with apoplexy disorder exhibit rapid and complete crown defoliation within a few weeks of symptom initiation. Symptoms are typically found throughout the entire crown and are initially expressed as wilting and chlorosis followed by scorching of leaves. Since the cause of apoplexy disorder is unknown, we set out to elucidate the water relations physiology underlying this condition. Stem water potential (Psi(s)) of healthy, asymptomatic trees remained high throughout the 2007 growing season, while that of apoplexy-afflicted trees decreased significantly with the onset of symptoms for both healthy-appearing and symptomatic portions of these trees. Psi(s)s were significantly reduced by at least 0.7 MPa in the lower, middle and upper portions of the symptomatic canopies compared with those from asymptomatic trees. Heat pulse velocities measured in the main trunk at three radial depths consistently decreased prior to the onset of symptoms and eventually reached zero with complete crown defoliation. Comparison of sap flow with predicted water use based on walnut evapotranspiration suggests that stomata of symptomatic trees were closing at higher evaporative demand prior to symptom formation. Specific hydraulic conductivity (K(s)) of symptomatic stems was significantly lower than that of asymptomatic stems, and no detectable K(s) could be measured on several of the symptomatic stem samples. However, shallow root K(s) did not significantly differ between symptomatic and asymptomatic trees, suggesting that hydraulic failure was isolated to the crown of these grafted trees. Light and scanning electron microscopy of stem and trunk sapwood revealed extensive tylose development in vessels throughout the crown of symptomatic trees. Analysis of the formation of tyloses on multiple dates revealed rapid development of these vessel occlusions in conjunction with visual symptom formation and dramatic decreases in sap flow. In 2008, tylose development was associated with elevated ethylene production in the active sapwood of symptomatic trees. The cause of elevated ethylene associated with tylose production and symptom formation is yet to be determined.

Detection of organophosphorus pesticides using potentiometric enzymatic membrane biosensor based on methylcellulose immobilization

In this research, a new potentiometric enzymatic membrane biosensor for the detection of organophosphorus pesticides (OPs) was constructed. The basic element of this biosensor was a pH electrode modified with an immobilized acetylcholinesterase layer formed by entrapment with methylcellulose, N,N-dimethylformamide, and bovine serum albumin. The response characteristics of the biosensor were measured and discussed. It was shown that there is a good linear relationship between the inhibition rate and the negative logarithm of OPs concentration in the range from 10(-7) to 10(-5) mol/L, with the detection limits of 10(-7) mol/L for the five pesticides. Moreover, the biosensor could resist the disturbances of below 10(-6) mol/L of Cu(2+) and Pb(2+), and below 10(-5) mol/L of Cd(2+). In addition, the measurement results obtained by the biosensor method were in good agreement with those obtained by the gas chromatography method. This method was successfully applied to detect OPs that remained in the potted lettuce.

Substituent Distribution and Clouding Behavior of Hydroxypropyl Methyl Cellulose Analyzed Using Enzymatic Degradation

The distribution of substituents along the polymer backbone will have a strong influence on the properties of modified cellulose. Endoglucanases were used to degrade three different batches of hydroxypropyl methyl cellulose (HPMC) derivatives with similar chemical properties. The phase separation of the HPMCs as a function of temperature, i.e., the clouding behavior, was analyzed prior to degradation. The total amount of unsubstituted glucose was determined using total acid hydrolysis followed by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The products after enzymatic degradation were analyzed with size-exclusion chromatography with online multiangle light scattering and refractive index detection and also with reducing end determination. To further characterize the formed products, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was employed for analysis of short-chained oligosaccharides. The different endoglucanases showed varying degradation capability of HPMC derivatives, depending on structure of the active site. The investigated HPMCs had different susceptibility to degradation by the endoglucanases. The results showed a difference in substituent distribution between HPMC batches, which could explain the differing clouding behaviors. The batch with the lowest cloud point was shown to contain a higher number of non-degradable, highly substituted regions.

In vitro evaluation of the mucoadhesive properties of polysaccharide-based nanoparticulate oral drug delivery systems

Impedance quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) measurements were performed in order to assess the mucoadhesive properties of hydrophobically modified (HM) derivatives of dextran (DEX), with an average molecular weight of 10,000 Da, and of hydroxypropylcellulose (HPC), with an average molecular weight of 80,000 Da. The measurements involved (1) treatment of a hydrophobic surface with bovine submaxillary gland mucin (BSM) under various pH conditions (2.0-8.0) and (2) treatment of the BSM layer with buffer solutions of the amphiphilic polysaccharides (pH 3.0 and 7.0). Control measurements were carried out with DEX, HPC, and chitosan (CH) used as a model mucoadhesive polymer. All HM-polysaccharides were shown to adsorb onto a BSM layer, the extent of adsorption increasing with increasing hydrophobicity of the samples. Under the same conditions, HPC and CH interacted with the BSM layer, but DEX showed no affinity to BSM. All the results suggest that HM-polysaccharide micellar systems have the potential of enhancing the bioavailability of poorly adsorbed drugs in peroral delivery.

Characterization of transcription factor binding to human papillomavirus type 16 DNA during cellular differentiation

Human papillomaviruses (HPVs) require terminal differentiation of the host cell to produce infectious virions. The process of viral maturation involves a variety of changes in the expression/activity of host proteins that lead to high-level replication of the viral genome and expression of the late viral genes. Although the late promoter regions of HPV type 16 (HPV-16) are still not fully characterized, differentiation-dependent regulation of viral genes is thought to involve changes in the binding of host cell transcription factors to the viral promoter and regulatory regions. Currently, very little is known about specific cellular transcription factors involved in this process. We used the Panomics TransSignal protein/DNA array to identify changes in the levels of cellular transcription factors during methylcellulose-induced differentiation of W12 (20863) cells containing HPV-16. We then identified the differentially expressed transcription factors that specifically bind to HPV-16 DNA, including the known promoter and regulatory regions. We have validated the results obtained from the Panomics array by Western blot analysis. Furthermore, by chromatin immunoprecipitation assays, we have shown that many of the transcription factors identified in the above screen bind to the HPV-16 promoter/regulatory sequences in vivo and that the level of this binding is increased during differentiation. This approach identified approximately 30 transcription factors that specifically bind to HPV-16 sequences and may be involved in regulating HPV-16 transcription during differentiation. Although some of these transcription factors have previously been suggested to be involved in HPV-16 transcription, a number of them represent novel viral DNA-host protein interactions.

New Approaches to the Analysis of Enzymatically Hydrolyzed Methyl Cellulose. Part 1. Investigation of the Influence of Structural Parameters on the Extent of Degradation

Six methyl celluloses (MCs), one with a degree of substitution (DS) of 1.32 and five with DS between 1.83 and 1.88, were thoroughly investigated. Monomer composition and methyl distribution in the polymer chain were analyzed after total or partial random hydrolysis and appropriate derivatization with gas chromatography (GC) and mass spectrometry (MS), respectively, and used as reference data. The same MCs were then hydrolyzed with an enzyme preparation of Trichoderma longibrachiatum and further investigated with size-exclusion chromatography with multiangle light scattering and refractive index detection (SEC-MALS/RI) and MS. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) in combination with various MS analyzers were compared with respect to quantification of the degradation products directly and after perdeuteriomethylation. The methyl group distribution in the oligomeric fractions and the average DS as a function of chain length were calculated from ESI mass spectra. With help of the reference analysis, patterns could be corrected for the unspecific contribution of end groups. By labeling and ESI tandem MS, our knowledge about the tolerance of the enzymes' sub-sites with respect to the number of methyl groups could be improved.

New Approaches to the Analysis of Enzymatically Hydrolyzed Methyl Cellulose. Part 2. Comparison of Various Enzyme Preparations

In this part of our studies, dealing with new approaches to the analysis of enzymatically hydrolyzed methyl cellulose, five different enzymes or enzyme preparations containing endoglucanases (from Bacillus agaradhaerens Cel 5A, Trichoderma reesei, Trichoderma viride, and two obtained from Trichoderma longibrachiatum) were used to hydrolyze six different methyl celluloses (MCs). The main goal was to investigate whether enzymes could be used for determination of the heterogeneity of the substituent distribution along the cellulose chain. To obtain information about the heterogeneity, it was necessary to gather information on how the enzymes affect hydrolysis. Size exclusion chromatography with multi-angle light scattering and refractive index detection (SEC-MALS/RI) was used to estimate the molar mass distribution of the MCs before and after hydrolysis. A novel internal standard addition method in combination with electrospray ionization ion trap mass spectrometry (ESI-ITMS) was used to determine the amount of formed oligomers. Two MCs, one with a degree of substitution (DS) of 1.8 and one with DS 1.3, were hydrolyzed with all of the five enzymes. The yield of summarized di- and trisaccharides was approximately 2% of the hydrolysis products for the MC with DS 1.8, whereas the product mixture, obtained from a MC with a DS of 1.3, contained 7-16% di- and trisaccharides. By a novel sample preparation method in combination with ESI-IT tandem MS, outlined in part 1 of this work, it was shown that the enzymes produced oligomers with the reducing end bearing no or only one substituent. Comparison of the methyl pattern at the nonreducing ends of the dimers and trimers indicated that the -2 subsite of the active complex is less tolerant than subsites -3 and +1. All enzymes had similar general selectivity toward the methyl substituents but also showed some differences. From both SEC-MALS/RI and ESI-ITMS, differences with respect to substituent distribution of MCs could be recognized but not for each enzyme used. Basic considerations for enzymatic hydrolysis and analysis of methyl cellulose were listed as a consequence of the results from the work.

c-Myc rapidly induces acute myeloid leukemia in mice without evidence of lymphoma-associated antiapoptotic mutations

Ectopic expression of c-Myc (Myc) in most primary cell types results in programmed cell death, and malignant transformation cannot occur without additional mutations that block apoptosis. The development of Myc-induced lymphoid tumors has been well studied and supports this model. Myc can be upregulated in acute myeloid leukemia (AML), but its exact role in myeloid leukemogenesis is unclear. To study its role in AML, we used a murine stem cell virus (MSCV) retroviral gene transfer/transplantation system to broadly express Myc in the bone marrow of mice either alone or in combination with antiapoptotic mutations. Myc expression in the context either of Arf/Ink4a loss or Bcl-2 coexpression induced a mixture of acute myeloid and acute lymphoid leukemias (AML+ALL). In the absence of antiapoptotic mutations however, all mice transplanted with MSCV-Myc (100%, n = 110) developed AML exclusively. MSCV-Myc-induced AML was polyclonal, readily transplantable, possessed an intact Arf-p53 pathway, and did not display cytogenetic abnormalities by spectral karyotyping (SKY) analysis. Lastly, we found that Myc preferentially stimulated the growth of myeloid progenitor cells in methylcellulose. These data provide the first direct evidence that Myc is a critical downstream effector of myeloid leukemogenesis and suggest that myeloid progenitors are intrinsically resistant to Myc-induced apoptosis.

Microchip Immobilized Enzyme Reactors for Hydrolysis of Methyl Cellulose

Microchip immobilized enzyme reactors (microIMERs) with immobilized endoglucanases were applied for the hydrolysis of methyl cellulose (MC). MCs of various molecular weights were hydrolyzed using two microIMERs containing immobilized celloendoglucanase Cel 5A from Bacillus agaradhaerens (BaCel 5A) connected in series. Hydrolysis by the microIMER could be confirmed from the average molar masses and molar mass distributions measured by size exclusion chromatography (SEC) with online multiangle light scattering and refractive index detection. Methylated cellooligosaccharides with degrees of polymerization (DP) between 1 and 6 formed during hydrolysis were analyzed by direct infusion electrospray ionization ion-trap mass spectrometry (ESI-ITMS). Mass spectra of microIMER- and batch-hydrolyzed samples were compared and no significant differences were found, indicating that microIMER hydrolysis was as efficient as conventional batch hydrolysis. A fast and automated hydrolysis with online MS detection was achieved by connecting the microIMER to high-performance liquid chromatography and ESI-ITMS. This online separation reduced the relative intensities of interfering signals and increased the signal-to-noise ratios in MS. The microIMER hydrolysates were also subjected to SEC interfaced with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. With this technique, oligomers with DP 3-30 could be detected. The hydrolysis by the microIMER was performed within 60 min, i.e. significantly faster compared with batch hydrolysis usually performed for at least 24 h. The microIMER also allowed hydrolysis after 10 days of continuous use. The method presented in this work offers new approaches for the analysis of derivatized cellulose and provides the possibility of convenient online, fast, and more versatile analysis compared with the traditional batch method.

Derivatization Using Dimethylamine for Tandem Mass Spectrometric Structure Analysis of Enzymatically and Acidically Depolymerized Methyl Cellulose

Structure analysis of partially depolymerized methyl cellulose was performed by nanoelectrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) and by matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-MS/MS). Dimethylamine (DMA) was used for the first time as a reducing end derivatization reagent for oligosaccharides. This is an attractive reagent since it could be easily removed from the reaction mixture. Most important it also introduces a basic functional group that increased the sensitivity in both MALDI and nano-ESI. Depolymerization was made in two ways: one by the cellulose selective endoglucanase 5A from Bacillus agaradhaerens (Ba Cel5A) and the other by trifluoroacetic acid. The DMA derivatives formed both protonated and sodiated molecules in nano-ESI and MALDI. Tandem MS of protonated molecules yielded predominantly Y fragments from which the distribution of the substituents in the oligomers could be measured. Fragments obtained in tandem MS of sodiated molecules provided information regarding the positions of the substituents within the anhydroglucose units (AGUs). It was found that Ba Cel5A could cleave glucosidic bonds also if the AGU on the reducing side of the bond was fully methylated. The combination of DMA derivatization and tandem MS was demonstrated as a tool for the characterization of endoglucanase selectivity.

Ovarian Monocyte Progenitor Cells: Phenotypic and Functional Characterization

Leukocytes of the macrophage lineage are abundant in the ovarian tissues and have an important function in both follicular development and regression of postovulatory follicles. In this study, we tested the hypothesis that continuous production of macrophages in the ovarian stroma is maintained by a resident population of progenitors. We established a long-term culture of ovarian follicular stromal cells from BALB/c and green fluorescent protein-transgenic (GFP-TG) C57BL/6 mice. Nonadherent cells were collected and tested for hematopoietic function in vitro and in vivo. Histological and ultrastructural analyses revealed a homogenous population of monocyte-like rounded cells. Nonadherent cells continued to proliferate in culture for several months without senescence. When plated at very low density in methylcellulose, these cells formed colonies consisting of monocyte-like cells. Ovarian monocyte-like cells reacted with CD45, CD11b, CD11c, and Ly6-Gr-1 cell surface markers. A distinct CD45low population within these cells reacted with CD117 (C-kit) surface marker, suggestive of a primitive hematopoietic progenitor. Fifty thousand nonadherent cells failed to provide radioprotection to lethally irradiated mice and thus were not considered to be equivalent to pluripotent hematopoietic stem cells. Ovarian nonadherent stromal cells were positive for alkaline phosphatase but lacked embryonic cell antigens stage-specific embryonic antigen (SSEA-1) and Oct-4. We conclude that in the ovaries, a higher requirement for macrophages is provided by a resident stromal population of progenitors whose progeny is restricted to the production of cells of the monocyte-macrophage lineage.

Fish oil supplementation in pregnancy modifies neonatal progenitors at birth in infants at risk of atopy

Dietary n-3 polyunsaturated fatty acids (PUFA) may represent a mode of allergy prevention. Cord blood (CB) CD34+ hemopoietic progenitors are altered in infants at risk of atopy. We therefore studied the effects of dietary n-3 PUFA supplementation during pregnancy on numbers and function of progenitors in neonates at high risk of atopy. In a double-blind study, atopic, pregnant women were randomized to receive fish oil capsules or placebo from 20 wk gestation until delivery. At birth, CB CD34+ cells were isolated and analyzed by flow cytometry for expression of cytokine (IL-5Ralpha, IL-3Ralpha, granulocyte/macrophage colony-stimulating factor Ralpha) or chemokine (CXCR4 and CCR3) receptors. CB cells were also cultured in methylcellulose assays for eosinophil/basophil colony-forming cells. At age 1 y, infants were clinically assessed for atopic symptoms and skin tests. Percentages of CB CD34+ cell numbers were higher after n-3 PUFA than placebo. Co-expression of cytokine or chemokine receptors on CD34 cells was not altered by n-3 PUFA supplementation. However, there were significantly more IL-5-responsive CB eosinophil/basophil colony forming units (Eo/B-CFU) in the fish oil, compared with the control, group. Overall, there was a positive association between CD34+ cells and IL-5-responsive Eo/B-CFU in CB and 1 y clinical outcomes, including atopic dermatitis and wheeze. Dietary n-3 PUFA supplementation during pregnancy in atopic mothers alters infant cord blood hemopoietic progenitor phenotype. This may have an impact on development of atopic disease.

Preparation and in vitro evaluation of sustained release tablet formulations of diclofenac sodium

The effects of formulation variables on the release profile of diclofenac sodium (DS) from hydroxypropylmethyl cellulose (HPMC) and chitosan matrix tablets were studied. DS tablets were prepared by wet granulation and direct compression methods and different ratios of HPMC and chitosan were used. Physical properties of the prepared tablets and targeted commercial sustained release (SR) tablet and the drug release were studied in tablets that were placed in 0.1 M HCl for 1 h and phosphate buffer solution was added to reach pH value of 7.5. In vitro studies showed that 20% HPMC contained SR formulation with direct (dry) compression method is the optimum formulation due to its better targeting profile in terms of release. This formulation also exhibited the best-fitted formulation into the zero order kinetics. The precision and accuracy of the analytical method were also checked. The repeatability and reproducibility of the method were also determined.

A novel pH-dependent gradient-release delivery system for nitrendipine

Nitrendipine, a dihydropyridine calcium antagonist, was used as a poorly water-soluble model drug. To improve its dissolution rate and extend the therapeutic period in vivo as well, a novel pH-dependent gradient-release drug delivery system for nitrendipine having a solid dispersed matrix structure was developed. Four factors, i.e. the amount of excipients, the pH of the dissolution medium, the rotating speed of the paddle of the dissolution apparatus and the particle size of the microspheres, all of which affect the drug-release behavior of the pH-dependent microspheres of the system were investigated in detail. The release profiles of the pH-dependent drug delivery system under simulated gastrointestinal tract pH conditions were also investigated. The results showed that the release rate of drug from the microspheres increased on increasing the amount of respective pH-dependent polymers formulated. Due to the fact that the active drug was incorporated in pH-dependent polymers and was present in a solid dispersion state in the microspheres, the release rate of the drug from the microspheres depended on the dissolution rate of the polymers, which was mainly influenced by the pH of dissolution medium, whereas the rotating speed of the paddle and the particle size of the microspheres had only a relatively minor effect. The release behavior of the system under simulated gastrointestinal tract conditions exhibited obvious gradient-release characteristics, showing that the release rate of the active drug could be controlled efficiently before the microspheres reached the appropriate region of the gut for absorption. These findings suggest that the pH-dependent drug delivery system could be fabricated by using present microspheres.

Mouse development and cell proliferation in the absence of D-cyclins

D-type cyclins (cyclins D1, D2, and D3) are regarded as essential links between cell environment and the core cell cycle machinery. We tested the requirement for D-cyclins in mouse development and in proliferation by generating mice lacking all D-cyclins. We found that these cyclin D1(-/-)D2(-/-)D3(-/-) mice develop until mid/late gestation and die due to heart abnormalities combined with a severe anemia. Our analyses revealed that the D-cyclins are critically required for the expansion of hematopoietic stem cells. In contrast, cyclin D-deficient fibroblasts proliferate nearly normally but show increased requirement for mitogenic stimulation in cell cycle re-entry. We found that the proliferation of cyclin D1(-/-)D2(-/-)D3(-/-) cells is resistant to the inhibition by p16(INK4a), but it critically depends on CDK2. Lastly, we found that cells lacking D-cyclins display reduced susceptibility to the oncogenic transformation. Our results reveal the presence of alternative mechanisms that allow cell cycle progression in a cyclin D-independent fashion.

A stable murine-based RD114 retroviral packaging line efficiently transduces human hematopoietic cells

Several barriers exist to high-efficiency transfer of therapeutic genes into human hematopoietic stem cells (HSCs) using complex oncoretroviral vectors. Human clinical trials to date have used Moloney leukemia virus-based amphotropic and gibbon ape leukemia virus-based envelopes in stable retroviral packaging lines. However, retroviruses pseudotyped with these envelopes have low titers due to the inability to concentrate viral supernatants efficiently by centrifugation without damaging the virus and low transduction efficiencies because of low-level expression of viral target receptors on human HSC. The RD114 envelope from the feline endogenous virus has been shown to transduce human CD34+ cells using transient packaging systems and to be concentrated to high titers by centrifugation. Stable packaging systems have potential advantages over transient systems because greater and more reproducible viral productions can be attained. We have, therefore, constructed and tested a stable RD114-expressing packaging line capable of high-level transduction of human CD34+ cells. Viral particles from this cell line were concentrated up to 100-fold (up to 10(7) viral particles/ml) by ultracentrifugation. Human hematopoietic progenitors from cord blood and sickle cell CD34+ cells were efficiently transduced with a Neo(R)-containing vector after a single exposure to concentrated RD114-pseudotyped virus produced from this cell line. Up to 78% of progenitors from transduced cord blood CD34+ cells and 51% of progenitors from sickle cell CD34+ cells expressed the NeoR gene. We also show transfer of a human beta-globin gene into progenitor cells from CD34+ cells from sickle cell patients with this new RD114 stable packaging system. The results indicate that this packaging line may eventually be useful in human clinical trials of globin gene therapy.

Double-layered mucoadhesive tablets containing nystatin

The objective of this work was to design a mucoadhesive tablet with a potential use in the treatment of oral candidosis. A 2-layered tablet containing nystatin was formulated. Lactose CD (direct compression), carbomer (CB), and hydroxypropylmethylcellulose (HPMC) were used as excipients. Tablets were obtained through direct compression. Properties such as in vitro mucoadhesion, water uptake, front movements, and drug release were evaluated. The immediate release layer was made of lactose CD (100 mg) and nystatin (30 mg). The CB:HPMC 9:1 mixture showed the best mucoadhesion properties and was selected as excipient for the mucoadhesive polymeric layer (200 mg). The incorporation of nystatin (33.3 mg) in this layer affected the water uptake, which, in turn, modified the erosion front behavior. Nystatin showed a first-order release. The polymeric layer presented an anomalous kinetic (n = 0.82) when this layer was individually evaluated. The mucoadhesive tablet formulated in this work releases nystatin quickly from the lactose layer and then in a sustained way, during approximately 6 hours, from the polymeric layer. The mixture CB:HPMC 9:1 showed good in vitro mucoadhesion. A swelling-diffusion process modulates the release of nystatin from this layer. A non-Fickian (anomalous) kinetic was observed.

Characterization of solid dispersions of itraconazole and hydroxypropylmethylcellulose prepared by melt extrusion, Part II

PURPOSE

This study was done to elucidate the physical and pharmaceutical properties of itraconazole-HPMC dispersions and the influence of water on the phase separation.

METHODS

Extrudates were prepared using a corotating twin-screw hot-stage extruder with fixed process parameters. Modulated-temperature differential scanning calorimetry (MTDSC) and DSC 111 were used to examine the mixing behavior of itraconazole and the carrier by evaluation of the glass transition region. High temperature diffuse reflectance infrared transform spectroscopy (HT-DRIFT) was performed to reveal interactions between itraconazole and HPMC. Dissolution was performed to investigate the pharmaceutical performance of the dispersions.

RESULTS

Although the dissolution rate of itraconazole significantly increased, we found that the solid dispersions do not form a homogeneous system. A different picture was obtained depending on the way MTDSC analysis was performed, i.e., using open or closed sample pans. Water can evaporate in open pans, which allows itraconazole to interact with HPMC and leads to a partially mixed phase. Analysis in hermetically closed pans revealed a further phase separation as water remains on the sample and impedes the interaction between drug and polymer.

CONCLUSION

Solid dispersions of itraconazole and HPMC do not form a homogeneous phase.

Tyloses and ecophysiology of the early carboniferous progymnosperm tree Protopitys buchiana

Trunk woods of Early Carboniferous Protopitys buchiana show the earliest example of tylose formation and the first record for a progymnosperm. Protopitys tyloses are more densely located in inner trunk woods and near growth layer boundaries. We suggest, therefore, that an altered physiological state of living ray cells, during dormancy and/or following water stress, was necessary to make the woods vulnerable to tylose formation. Coupled with the distribution and proximity of abundant wood ray parenchyma to large xylem conducting cells, the positions of conduits filled with tyloses can be interpreted as ecophysiological responses of the plant to changes in local environment. In addition, some xylem conducting cells might have functioned as vessels. Fungal hyphae are present in some tracheary cells and in some areas with tyloses, but there is no evidence for wood trauma; we conclude, therefore, that these particular cases of tyloses are probably not induced by wound trauma. Protopitys buchiana wood thus shows structure/function similarities to modern woods with vessels, such as those of dicot angiosperms. This implies that ancient and modern plant ecophysiological responses correlate well with the physical parameters of their cellular construction.

Sample preparation effects in matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry of partially depolymerised methyl cellulose

Methyl cellulose (MC) was partially depolymerised and the oligomers thus obtained were studied by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The depolymerisation was either enzymatic or acidic. Fractions of enzymatically depolymerised MC were collected from size-exclusion chromatography and subjected to a sample preparation investigation. Several MALDI matrices and solvents were evaluated. The results showed that the solvent choice had a significant effect on the measured degree of substitution (DS). Aprotic solvents produced higher DS values, which was most likely due to poor solubility of species with low DS. The obtained signal intensity, however, did not correlate with the solubility but seemed to be more dependent on certain matrix/solvent combinations. All the matrices attempted produced mass spectra with sufficient signal intensity for accurate peak area calculation. The choice of matrix did not have any significant effect on the measured DS. Sample spots obtained from organic solvents had a more homogeneous distribution of the analyte and smaller crystals than those obtained from water. This increased both the reproducibility and peak resolution and in addition the analysis time was shorter. DS measurements were performed on two acidically depolymerised MCs with different nominal DS values. It was easy to distinguish between the two MCs, and the measured DS values agreed well with the values supplied by the manufacturers.

Stability of ingested methylcellulose in the rat determined by polymer molar mass measurements by light scattering

Methylcellulose (MC) is ingested by humans in food and pharmaceutical formulations. The functional properties of MC like those of other linear polymers depend primarily on polymer length or molar mass for largely linear polymers. Although many studies in animals and humans have shown complete excretion of MC, in vitro human fecal fermentation studies indicate that MC can be degraded and presumably lose some of its functionality. In this study, MC polymer distribution in the feces from rats fed a diet containing 8% methylcellulose were compared to the fed MC. The water-soluble polymers in the feces were separated by a size exclusion chromatography (SEC) and the polymer distributions determined by multiple angle laser light scattering (MALLS). Detection of the fluorescent MC-calcofluor complex was used to confirm the identity of the eluting MC peak. All dietary MC was recovered in the feces. There is a small shift (P < 0.06) in the weight-averaged molecular weight of polymer distribution of MC extracted from the feces to 2.71 +/- 0.15 x 10(5) g/mol from 3.15 +/- 0.02 x 10(5) g/mol in the standard. There is also an increase in the polydispersity from 1.21 in the standard to 1.8 in the fecal extract. The distribution of the substituted methoxylated glucose monomers by gas chromatography also confirms the stability of MC fed to rats. The amount of actual hydrolysis is estimated to be about 0.1 glycosidic linkage/molecule. MC is not easily determined by standard dietary fiber methods, and SEC with MALLS and/or fluorescence may be a useful alternative.

Transformation of bone marrow B-cell progenitors by E2a-Hlf requires coexpression of Bcl-2

The chimeric transcription factor E2a-Hlf is an oncoprotein associated with a subset of acute lymphoblastic leukemias of early B-lineage derivation. We employed a retroviral transduction-transplantation approach to evaluate the oncogenic effects of E2a-Hlf on murine B-cell progenitors harvested from adult bone marrow. Expression of E2a-Hlf induced short-lived clusters of primary hematopoietic cells but no long-term growth on preformed bone marrow stromal cell layers comprised of the AC6.21 cell line. Coexpression with Bcl-2, however, resulted in the sustained self-renewal of early preB-I cells that required stromal and interleukin-7 (IL-7) support for growth in vitro. Immortalized cells were unable to induce leukemias after transplantation into nonirradiated syngeneic hosts, unlike the leukemic properties and cytokine independence of preB-I cells transformed by p190(Bcr-Abl) under identical in vitro conditions. However, bone marrow cells expressing E2a-Hlf in combination with Bcl-2, but not E2a-Hlf alone, induced leukemias in irradiated recipients with long latencies, demonstrating both a requirement for suppression of apoptosis and the need for further secondary mutations in leukemia pathogenesis. Coexpression of IL-7 substituted for Bcl-2 to induce the in vitro growth of pre-B cells expressing E2a-Hlf, but leukemic conversion required additional abrogation of undefined stromal requirements and was associated with alterations in the Arf/Mdm2/p53 pathway. Thus, E2a-Hlf enhances the self-renewal of bone marrow B-cell progenitors without inciting a p53 tumor surveillance response or abrogating stromal and cytokine requirements for growth, which are nevertheless abrogated during progression to a leukemogenic phenotype.

In-vitro studies of diclofenac sodium controlled-release from biopolymeric hydrophilic matrices

PURPOSE

The objective of this study was to develop uncoated HPMC matrix tablets, evaluating the relationship and influence of different content levels of microcrystalline cellulose (MCC), starch, and lactose, in order to achieve a zero-order release of Diclofenac Sodium.

METHODS

HPMC matrix tablets of Diclofenac Sodium using microcrystalline cellulose (MCC), starch, and lactose were prepared by wet granulation process. The USP paddle method was selected to perform the dissolution profiles carried out in 900 mL 0.1 N HCl, and phosphate buffer.

RESULTS

There was no significant difference in drug release between the hydrophilic matrices when the HPMC concentration was modified in low percentage. Release kinetics of Diclofenac Sodium from these swollen matrices was principally regulated by starch (17 percent) or lactose (17 percent), even on the presence of MCC. When starch (8.5 percent) and lactose (8.5 percent) were mixed at lower concentration in a ratio 1:1, MCC (5 percent or 7,5 percent) appeared to control the drug release. The release profile remained unchanged after three months storage of tablets. The best-fit release kinetics was achieved with the zero-order plot, followed by the Higuchi and first-order equations. The data obtained proved that the formulations are useful for a sustained release of Diclofenac, due to the percentage released after 8 hours is nearly to 70 percent.

CONCLUSIONS

The release of Diclofenac Sodium was influenced by the presence of MCC, and by the different concentrations of starch and lactose. Drug release kinetics from these formulations corresponded best to the zero-order kinetics. Compared to conventional tablets, release of the model drug from these HPMC matrix tablets was prolonged; as a result, an oral release dosage form to avoid the gastrointestinal adverse effects was achieved.

Double-layered mucoadhesive tablets containing nystatin

The objective of this work was to design a mucoadhesive tablet with a potential use in the treatment of oral candidosis. A 2-layered tablet containing nystatin was formulated. Lactose CD (direct compression), carbomer (CB), and hydroxypropylmethylcellulose (HPMC) were used as excipients. Tablets were obtained through direct compression. Properties such as in vitro mucoadhesion, water uptake, front movements, and drug release were evaluated. The immediate release layer was made of lactose CD (100 mg) and nystatin (30 mg). The CB:HPMC 9:1 mixture showed the best mucoadhesion properties and was selected as excipient for the mucoadhesive polymeric layer (200 mg). The incorporation of nystatin (33.3 mg) in this layer affected the water uptake, which, in turn, modified the erosion front behavior. Nystatin showed a first-order release. The polymeric layer presented an anomalous kinetic (n = 0.82) when this layer was individually evaluated. The mucoadhesive tablet formulated in this work releases nystatin quickly from the lactose layer and then in a sustained way, during approximately 6 hours, from the polymeric layer. The mixture CB:HPMC 9:1 showed good in vitro mucoadhesion. A swelling-diffusion process modulates the release of nystatin from this layer. A non-Fickian (anomalous) kinetic was observed.

Efficiency of embryoid body formation and hematopoietic development from embryonic stem cells in different culture systems

Embryonic stem (ES) cells have tremendous potential as a cell source for cell-based therapies. Realization of that potential will depend on our ability to understand and manipulate the factors that influence cell fate decisions and to develop scalable methods of cell production. We compared four standard ES cell differentiation culture systems by measuring aspects of embryoid body (EB) formation efficiency and cell proliferation, and by tracking development of a specific differentiated tissue type-blood-using functional (colony-forming cell) and phenotypic (Flk-1 and CD34 expression) assays. We report that individual murine ES cells form EBs with an efficiency of 42 +/- 9%, but this value is rarely obtained because of EB aggregation-a process whereby two or more individual ES cells or EBs fuse to form a single, larger cell aggregate. Regardless of whether EBs were generated from a single ES cell in methylcellulose or liquid suspension culture, or aggregates of ES cells in hanging drop culture, they grew to a similar maximum cell number of 28,000 +/- 9,000 cells per EB. Among the three methods for EB generation in suspension culture there were no differences in the kinetics or frequency of hematopoietic development. Thus, initiating EBs with a single ES cell and preventing EB aggregation should allow for maximum yield of differentiated cells in the EB system. EB differentiation cultures were also compared to attached differentiation culture using the same outputs. Attached colonies were not similarly limited in cell number; however, hematopoietic development in attached culture was impaired. The percentage of early Flk-1 and CD34 expressing cells was dramatically lower than in EBs cultured in suspension, whereas hematopoietic colony formation was almost completely inhibited. These results provide a foundation for development of efficient, scalable bioprocesses for ES cell differentiation, and inform novel methods for the production of hematopoietic tissues.

Growth of rainbow trout hemopoietic cells in methylcellulose and methods of monitoring their proliferative response in this matrix

A technique for the clonal culture of rainbow trout leukocytes in a methylcellulose matrix can be used to identify growth factors and other substances affecting cell proliferation and development in fish. Methylcellulose supports colony formation by rainbow trout leukocytes isolated from the major hemopoietic organ, the pronephros. The addition of rainbow trout serum dramatically increased the number of colonies formed, scored by counting colonies. As an alternative measure of cell proliferation, 3H-thymidine incorporation by cells can be easily measured in methylcellulose cultures. This method requires only small amounts of test substances, is rapid, and is superior for assessing the growth-stimulating ability of some substances, such as bacterial lipopolysaccharide, which stimulated growth but not the formation of discreet colonies by rainbow trout cells.

Activation of Innate Immunity in Nonhuman Primates Following Intraportal Administration of Adenoviral Vectors

The innate immune response to intraportally infused adenoviral vector was evaluated in rhesus monkeys. A first-generation adenovirus-expressing lacZ (Ad-lacZ) was administered at a dose just below that which causes severe morbidity. The response to vector was evaluated for the initial 24 h following infusion. Clinical findings during this time were primarily limited to petechiae, consistent with the development of thrombocytopenia and biochemical evidence of disseminated intravascular coagulation. Serum transaminases were elevated and a lymphopenia developed. Tracking of fluorescent-labeled vector demonstrated distribution to macrophages and dendritic cells of the spleen and Kupffer cells of the liver. A systemic release of the cytokine IL-6 occurred soon after vector infusion. Analysis of splenic cells revealed acute activation of macrophages and dendritic cells followed by massive apoptosis. Bone marrow cultures demonstrated normal erythroid and primitive progenitors with a significant decrease in myeloid progenitors. Similar findings, except the abnormality in bone marrow cultures, were observed in monkeys who received an identical dose of Ad-lacZ in which vector genes were inactivated with psoralen and UV irradiation. These data suggest that inadvertent targeting of antigen-presenting cells following intraportal infusion of vector leads to a systemic cytokine syndrome which may be triggered by the viral capsid proteins.

Antitumor effects of a novel phenoxazine derivative on human leukemia cell lines in vitro and in vivo

2-Amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one (Phx) was synthesized by reacting 2-amino-5-methylphenol with bovine hemolysates. Because Phx is a phenoxazine derivative like actinomycin D, we examined its effects on the proliferation of the human leukemia cell lines K562, HL-60, and HAL-01. Phx inhibited proliferation and induced apoptosis in all of the leukemia cell lines we tested, in a dose-dependent manner. We further investigated the antitumor effect of this compound on HAL-01-bearing nude mice. Treatment with Phx markedly reduced the tumor growth rate in the experimental group, as compared with the control group. Moreover, Phx was found to have few adverse effects on weight loss and WBC count. In addition, we examined the effects of Phx on human normal hematopoietic progenitor cells by a clonogenic assay, and we observed less suppression of normal progenitor cells than of leukemic progenitors. These results suggest that Phx may be used to treat patients affected by different types of leukemia.

Interaction between hydroxypropyl methylcellulose and biphasic calcium phosphate after steam sterilisation: capillary gas chromatography studies

The purpose of this study was to check the chemical stability of an injectable bone substitute (IBS) composed of a 50/50 w/w mixture of 2.92% hydroxypropyl methylcellulose (HPMC) solution in deionized water containing biphasic calcium phosphate (BCP) granules (60% hydroxyapatite/40% beta-tricalcium phosphate w/w). After separation of the organic and mineral phases, capillary gas chromatography (GC) was used to study the possible modification of HPMC due to the contact with BCP granules following steam sterilisation and 32 days storage at room temperature. HPMC was extracted from IBS in aqueous medium, and a dialytic method was then used to extract calcium phosphate salts from the HPMC. The percentage of HPMC extracted from BCP was 98.5%+/-0.5%, as measured by UV. GC showed no chemical modifications after steam sterilisation and storage.

An atomic force microscopy investigation of bioadhesive polymer adsorption onto human buccal cells

Atomic force microscopy (AFM) was used to examine the buccal cell surface in order to image the presence of adsorbed bioadhesive polymers identified from previous work. Isotonic saline solution (5 ml) containing either polycarbophil (pH 7.6), chitosan (pH 4.5) or hydroxypropyl methylcellulose (pH 7.6) (0.5% w/v) was exposed to freshly collected buccal cells (ca. 48x10(4) cells/test) for 15 min at 30 degrees C. The cells were then rinsed with a small volume of double distilled water, allowed to air-dry on a freshy cleaved mica surface and imaged using contact mode AFM. Untreated cells showed relatively smooth surface characteristics, with many small 'crater-like' pits and indentations spread over cell surfaces. Cells that had been treated with all the investigated polymers appeared to have lost the crater and indentation characteristic and gained a higher surface roughness. These results suggest that polymer chains had adsorbed onto the cell surfaces. Quantitative image analysis of cell topography showed significant increases (P<0.05) in arithmetic roughness average (R(a)) for all the investigated polymer treated cells surfaces with respect to untreated control specimens. The changes in surface topography indicate the presence of adsorbed polymer, confirming previous work. This study demonstrates the suitability of AFM as a powerful and sensitive technique for detecting and imaging bioadhesive polymers present on mucosal cell surfaces.

Synthesis, X-ray structure, and anti-leukemic activity of oxovanadium(IV) complexes

In a systematic effort to identify and develop effective anticancer agents, four oxovanadium(IV) complexes with 1,10-phenanthroline (Phen) or 4,7-dimethyl-1,10-phenanthroline (Me2-Phen) as ligand(s) were synthesized and characterized. Among the four oxovanadium(IV) complexes synthesized, the crystal structure of the bis(phenanthroline)oxovanadium(IV) complex bis(1,10-phenanthroline)sulfatooxovanadium(IV) ([VO(SO4)(Phen)2], compound 1) has been determined. Compound 1 crystallized in the space group P2(1)/n with unit cell parameters a = 14.2125(17) A, b = 10.8628(13) A, c = 20.143(2) A, alpha = 90 degrees, beta = 102.569(2) degrees, gamma = 90 degrees, V = 3035.3(6) A3, and Z = 4. The refinement of compound 1 by full-matrix least-squares techniques gave an R factor of 0.0785 for 4356 independent reflections. The structure contains two enantiomorphous molecules, lambda and delta, which are related by an inversion center. Compound 1 exhibited 3.5-fold more potent cytotoxic activity against NALM-6 human leukemia cells than the mono(phenanthroline)oxovanadium(IV) complex (diaqua)(1,10-phenanthroline)sulfatooxovanadium(IV) ([VO(SO4)(Phen)(H2O)2], compound 2) (IC50 values: 0.97+/-0.10 microM versus 3.40+/-0.20 microM: P=0.0004). Methyl substitution in the phenanthroline ligand enhanced the anti-leukemic activity of the mono(phenanthroline)oxovanadium(IV) complex 4.4-fold (IC50 values: 0.78+/-0.10 microM, compound 4, versus 3.40+/-0.20 microM, compound 2; P=0.0003) and the anti-leukemic activity of the bis(phenanthroline)oxovanadium(IV) complex 5.7-fold (IC50 values: 0.17+/-0.02 microM, compound 3, versus 0.97+/-0.10 microM, compound 1; P=0.001). The leading oxovanadium compound, bis(4,7-dimethyl-1,10-phenanthroline)sulfatooxovanadium(IV) ([VO(SO4)(Me2-Phen)2], compound 3) triggered the production of reactive oxygen species (ROS) in human leukemia cells, caused G1-arrest and inhibited clonogenic growth at nanomolar concentrations.

Drosophila ACT88F indirect flight muscle-specific actin is not N-terminally acetylated: a mutation in N-terminal processing affects actin function

Many eukaryotic proteins are co and post-translationally modified at their N termini by removal of one or two amino acid residues and N(alpha)-acetylation. Actins show two different forms of N-terminal processing dependent on their N-terminal sequence. In class II actins, which include muscle actins, the common primary sequence of Met-Cys-Asp-actin is processed to acetyl-Asp-actin. The functional significance of this in vivo is unknown. We have studied the indirect flight muscle-specific actin, ACT88F, of Drosophila melanogaster. Our results show that ACT88F is N-terminally processed in vivo as a class II actin by removal of the first two amino acid residues (Met and Cys), but that uniquely the N terminus is not acetylated. In addition we show that ACT88F is methylated, probably at His73. Flies carrying the mod(-) mutation fail to complete post-translational processing of ACT88F. We propose that the mod gene product is normally responsible for removing N-acetyl-cysteine from actin. The biological significance of this process is demonstrated by observations that retention of the N-acetyl-cysteine in ACT88F affects the flight muscle function of mod(-) flies. This suggests that the extreme N terminus affects actomyosin interactions in vivo, a proposal we have examined by in vitro motility assays of ACT88F F-actin from mod(-) flies. The mod(-) actin only moves in the presence of methylcellulose, a viscosity-enhancing agent, where it moves at velocities slightly, but significantly, reduced compared to wild-type. These data confirm that N-acetyl-cysteine at the N terminus affects actomyosin interactions, probably by reducing formation of the initial actomyosin collision complex, a process known to involve the actin N terminus.

Controlled transdermal delivery of propranolol using HPMC matrices: design and in-vitro and in-vivo evaluation

To improve bioavailability and achieve a smoother plasma-concentration profile as compared with oral administration, a matrix-dispersion-type transdermal delivery system was designed and developed for propranolol using different ratios of hydroxypropylmethylcellulose (HPMC) K4M, K15M and K100M. Formulations were evaluated for in-vitro dissolution characteristics using a Cygnus' sandwich-patch holder. Drug release followed Higuchi rather than zero-order or first-order kinetics. In-vivo evaluation was carried out on healthy volunteers (21+/-1.41 years; 60.89+/-5.35 kg) following the balanced incomplete block design. The dissolution rate constant (k) and data generated from plasma and urine (Cmax, maximum plasma concentration; t(max), time to reach peak plasma concentration; AUC, area under the curve; k(e), elimination rate constant; t1/2e, elimination half-life; k(a), absorption rate constant; t1/2a, absorption half-life) were evaluated statistically by two-way analysis of variance. Statistically excellent correlation was found between the percentage of drug absorbed and Cmax, AUC0-24 and AUC0-infinity. A highly significant difference (P < 0.001) was observed when Cmax and AUC0-infinity, generated from plasma and urine were compared, but k(e), t1/2e, k(a) and t1/2a did not differ significantly (P > 0.1). We conclude that urinary excretion data may be used as a simpler alternative to blood level data in studying the kinetics of absorption and deriving the absorption parameters.

TRAIL is a potent inducer of apoptosis in myeloma cells derived from multiple myeloma patients and is not cytotoxic to hematopoietic stem cells

TRAIL, the ligand for the newly discovered DR-4 and DR-5 receptor, is a member of the TNF family of death signal transduction proteins with a mechanism of cell death similar to that of Fas and Fas ligand (Fas-L) system. We provide first time evidence that TRAIL is a potent inducer of apoptosis in multiple myeloma (MM) cell lines. TRAIL effectively induced extensive apoptosis in 8226 and ARP-1 MM cells in a time- and dose-dependent manner. Apoptosis with TRAIL reached about 80% within 48 h of treatment with a dose of 160 ng/ml. Furthermore, we provide first time evidence that similar to Fas, TRAIL-induced apoptosis is not blocked by bcl-2 in MM cell lines. Most importantly, TRAIL induced substantial apoptosis in freshly isolated, flow-sorted myeloma cells obtained from different MM patients expressing variable levels of bcl-2. Finally, we demonstrate for the first time that TRAIL is not cytotoxic to purified CD34+/CD45dim hematopoietic stem cells and does not inhibit CFU-GM or BFU-E colony formation in methylcellulose.

Short-term effects of mineral particle sizes on cellular degradation activity after implantation of injectable calcium phosphate biomaterials and the consequences for bone substitution

This in vivo study investigated the influence of two calcium phosphate particle sizes (40-80 microm and 200-500 microm) on the cellular degradation activity associated with the bone substitution process of two injectable bone substitutes (IBS). The tested biomaterials were obtained by associating a biphasic calcium phosphate (BCP) ceramic mineral phase and a 3% aqueous solution of a cellulosic polymer (hydroxypropylmethylcellulose). Both were injected into osseous defects at the distal end of rabbit femurs for 2- and 3-week periods. Quantitative results for tartrate-resistant acid phosphatase (TRAP) cellular activity, new bone formation, and ceramic resorption were studied for statistical purposes. Positive TRAP-stained degradation cells were significantly more numerous for IBS 40-80 than IBS 200-500, regardless of implantation time. BCP degradation was quite marked during the first 2 weeks for IBS 40-80, and bone colonization occurred more extensively for IBS 40-80 than for IBS 200-500. The resorption-bone substitution process occurred earlier and faster for IBS 40-80 than IBS 200-500. Both tested IBS displayed similar biological efficiency, with conserved in vivo bioactivity and bone-filling ability. Differences in calcium phosphate particle sizes influenced cellular degradation activity and ceramic resorption but were compatible with efficient bone substitution.

Stirred culture of peripheral and cord blood hematopoietic cells offers advantages over traditional static systems for clinically relevant applications

The ability to culture hematopoietic cells in readily characterizable and scalable stirred systems, combined with the capability to utilize serum-free medium, will aid the development of clinically attractive bioreactor systems for transplantation therapies. We thus examined the proliferation and differentiation characteristics of peripheral blood (PB) mononuclear cells (MNC), cord blood (CB) MNC, and PB CD34(+) cells in spinner flasks and (control) T-flask cultures in both serum-containing and serum-free media. Hematopoietic cultures initiated from all sources examined (PB MNC, CB MNC, and PB CD34(+) cells) grew well in spinner vessels with either serum-containing or serum-free medium. Culture proliferation in spinner flasks was dependent on both agitator design and RPM as well as on the establishment of critical inoculum densities (ID) in both serum-containing (2 x 10(5) MNC/mL) and serum-free (3 x 10(5) MNC/mL) media. Spinner flask culture of PB MNC in serum-containing medium provided superior expansion of total cells and colony-forming cells (CFC) at high ID (1.2 x 10(6) cells/mL) as compared to T-flask controls. Serum-free spinner culture was comparable, if not superior, to that observed in serum-containing medium. This is the first report of stirred culture of PB or CB MNC, as well as the first report of stirred CD34(+) cell culture. Additionally, this is the first account of serum-free stirred culture of hematopoietic cells from any source.

In vitro and in vivo erosion of two different hydrophilic gel matrix tablets

The aim of the present work was to establish in vivo predictive in vitro tests for the tablet erosion of two different compositions (A and B) of hydrophilic matrix tablets based on hydroxypropyl methylcellulose. The tablet erosion was studied in a modified USP II apparatus at different agitation intensities and ionic strengths according to 2(2) factorial design. The in vivo tablet erosion was studied in 8 healthy human volunteers by gamma scintigraphy after administration of the tablets together with breakfast. In vitro agitation intensity increased the erosion rate for both tablets whereas increased ionic strength caused a slower rate for tablet A and a faster rate for tablet B. The choice of in vitro testing conditions proved to be critical for the attainment of in vivo predictive results. The best in vitro/in vivo correlation for the two formulations was obtained at a paddle stirring rate of 140 rpm and a ionic strength of 0.14 obtained by addition of sodium chloride.

A novel serum free system for cloning human megakaryocytic progenitors (CFU-Meg). The role of thrombopoietin and other cytokines on bone marrow and cord blood CFU-Meg growth under serum free conditions

Human megakaryocytic progenitors (CFU-Megs) are usually cloned in plasma clot cultures. Since the medium employed to prepare plasma clot contains animal or human serum, there exists a potential risk that CFU-Megs growing in vitro could be exposed to the serum derived megakaryopoietic inhibitors. To address this issue, we aimed to establish a relatively simple "serum free" cloning model for these progenitors. Accordingly, we found that if human bone marrow or cord blood CD34+ cells are plated in the methylcellulose medium containing serum substitute, and are stimulated with recombinant thrombopoietin (TpO), they exclusively form CFU-Meg colonies. Subsequently these colonies can be easily scored with an inverted microscope based only on their morphological criteria. We found that the cloning efficiency of CFU-Megs was higher in our serum free cloning system than in the traditional plasma clot cultures. Since the model proposed in this paper is relatively simple, and moreover does not require time consuming immunostaining to identify CFU-Meg colonies, it should be widely recommended for studying in vitro human megakaryopoiesis. We also found, that under serum free conditions TpO is crucial for CFU-Meg formation. In absence of TpO, neither gp 130 activating cytokines (IL-6, IL-11, LIF, CNTF) nor the other hematopoietic growth factors or cytokines (KL, IL-3, GM-CSF, EpO) were able, when added alone, to stimulate the growth of human CFU-Meg colonies. Finally, we report also that cord blood CD34+ cells are enriched in megakaryocytic progenitors, and moreover, CFU-Megs from cord blood possess a higher proliferative capacity than CFU-Megs isolated from normal adult bone marrow.

Central action of adrenomedullin to inhibit gastric emptying in rats

The central action of human adrenomedullin (AM) to influence gastric emptying and the peripheral mechanisms involved were studied in conscious rats. The 20-min rate of gastric emptying of a methylcellulose solution was assessed after intracisternal (i.c.) injection of AM or rat alpha-calcitonin gene-related peptide (alphaCGRP). AM and alphaCGRP dose-dependently inhibited gastric emptying with i.c. ED50 values of 120 and 100 pmol, respectively. Human proadrenomedullin N-terminal 20 peptide (150-600 pmol, i.c.) and AM (150 pmol, i.v.) had no effect. The inhibitory actions of AM and alphaCGRP (150 pmol, i.c.) were completely blocked by the CGRP antagonist, human CGRP-(8-37) injected i.c. at 30 microg, but not at 15 microg. The CRF antagonist, [D-Phe12,Nle(21,38),C(alpha)MeLeu37]CRF-(12-41) (10 microg/rat) injected i.c. prevented i.c. rat/human CRF (150 pmol)-induced 53% inhibition of gastric emptying while not modifying the effect of AM. The action of AM (150 pmol, i.c.) was abolished by bilateral adrenalectomy or the beta-adrenergic blocker, propranolol (1 mg/kg, i.p.), but was not altered by indomethacin (5 mg/kg, i.p.) or subdiaphragmatic vagotomy. These results indicate that i.c. AM and alphaCGRP equipotently inhibit gastric emptying through mechanisms similarly antagonized by a high dose of CGRP-(8-37). The central AM action is mediated through adrenal-dependent, beta-adrenergic pathways independently from activation of central CRF receptors.