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Freezing has been widely used for long-term food preservation. However, freezing-thawing (FT) treatment usually influences the texture and structure of food gels such as konjac. For their texture control after FT treatment, it is important to clarify the structural change of food gels during the FT process. In this study, we investigated the aggregated structures of konjac glucomannan (GM) gels during the FT process using simultaneous synchrotron small-angle X-ray/wide-angle X-ray scattering (SAXS/WAXS) techniques. The FT treatment resulted in more crystallization of GM, and consequently, a large increase in compressive stress. In-situ SAXS/WAXS measurements revealed the following findings: on freezing, water molecules came out of the aggregated phase of GM and after the thawing, they came back into the aggregated phase, but the aggregated structure did not return to the one before the freezing; the gel network enhanced the inhomogeneity due to the growth of ice crystals during freezing. Furthermore, we examined the influence of additives such as polyvinyl (alcohol) (PVA) and antifreeze glycoprotein (AFGP) on the mechanical and structural properties of freeze-thawed GM gels. Although the addition of PVA and AFGP suppressed the crystallization of GM, it could not prevent the growth of ice crystals and the increase in the inhomogeneity of the gel network. As a result, the compressive stresses for freeze-thawed GM gels containing PVA or AFGP were significantly higher compared with those of GM gels without FT treatments, although they were lower than those of freeze-thawed GM gels. The findings of this study may be useful for not only the texture control of freeze-thawed foods but also the improvement of the mechanical performance of the biomaterials.

The effect of cellulose nanofibers (CNFs) on the mechanical and structural properties of poly (vinyl alcohol) (PVA) hydrogels cross-linked dually by a freezing/thawing method and a cross-linker (borax) was investigated using tensile tests, FT-IR measurements and synchrotron simultaneous small-angle/wide-angle X-ray scattering (SAXS/WAXS). The cross-linking with borax and addition of CNF greatly improved the tensile performance of the PVA hydrogels prepared in the freezing/thawing method, e.g., the dual cross-linking resulted in remarkable increase in the fracture strain, the Young’s modulus and the tensile strength. The fiber length effect on the mechanical properties of the CNF/PVA/borax hydrogels was examined, so that addition of CNF with longer fiber length increased the tensile modulus, whereas addition of CNF with shorter length caused extensibility higher than 1000% even at high CNF concentrations. SAXS/WAXS and FT-IR measurements have revealed that PVA was crystallized due to the freezing/thawing process, and both of PVA and CNF were cross-linked with borax, and hydrogen bonds between hydroxy groups of PVA (or/and CNF) were formed, indicating that the multiple cross-linking is effective for improvement of the tensile performance. In addition, the CNF/PVA/borax gel with the multi-physical cross-linking was found to possess the ability of the self-healing.

Acetyl-CoA is a key intermediate situated at the intersection of many metabolic pathways. The reliance of histone acetylation on acetyl-CoA enables the coordination of gene expression with metabolic state. Abundant acetyl-CoA has been linked to the activation of genes involved in cell growth or tumorigenesis through histone acetylation. However, the role of histone acetylation in transcription under low levels of acetyl-CoA remains poorly understood. Here, we use a yeast starvation model to observe the dramatic alteration in the global occupancy of histone acetylation following carbon starvation; the location of histone acetylation marks shifts from growth-promoting genes to gluconeogenic and fat metabolism genes. This reallocation is mediated by both the histone deacetylase Rpd3p and the acetyltransferase Gcn5p, a component of the SAGA transcriptional coactivator. Our findings reveal an unexpected switch in the specificity of histone acetylation to promote pathways that generate acetyl-CoA for oxidation when acetyl-CoA is limiting.

Curdlan was grafted to poly(vinyl alcohol) (PVA) to form a porous scaffold. The grafted PVA-curdlan 3D scaffold was then examined by Fourier transform infrared spectroscopy (FT-IR). Grafting increased the water absorbency of the scaffold by 280%. Scanning electron microscopic (SEM) observations of the material revealed that the 3D scaffold was highly porous when it was fabricated using a homogenizer at 300rpm. Compression testing revealed that, increasing the amount of curdlan increased the strength of the 3D scaffold to 8-16×10-3MPa. Over 28days, various enzymes degraded the 3D scaffold, causing a weight loss of up to 20-40%. In vivo tests revealed favorable cell proliferation and growth in a 3D scaffold.

PURPOSE Growing evidence has demonstrated that aberrant expression of integrin α2β1 might contribute to the invasion, metastasis and drug resistance of non-small cell lung cancer (NSCLC). Thus, the integrin α2β1 targeting 68Ga-DOTA-A2B1 tracer was validated in NSCLC in contrast to accumulation of the clinically used 18F-FDG PET tracer to see if 68Ga-DOTA-A2B1-PET imaging can offer a valuable and critical diagnostic imaging criterion for the identification of phenotypes of aggressive lung cancer. METHODS To verify the prognostic value of integrin α2β1, several quantitative and functional in vitro assays were validated in different NSCLC cell lines (CL1-0, CL1-5, A549 and selected A549++ cells). Positron emission tomography (PET) imaging studies using both standard 18F-FDG and a newly developed 68Ga-labeled integrin α2β1 (68Ga-DOTA-A2B1) tracer were sequentially performed on mice with lung tumor xenografts in different anatomic locations (subcutaneous, orthotopic and osseous) to validate the targeting capability of the 68Ga-DOTA-A2B1 tracers. Treatment responses were monitored by injecting animals with metastatic bone tumors with 5 mg/kg doxorubicin. All in vivo treatment responses in each treatment subgroup were monitored with a PET imaging system to evaluate the up-regulation of integrin expression at the earliest stage of treatment (6 h). RESULTS The PET and computed tomography (CT) images from NSCLC xenograft animals unambiguously demonstrated accumulation of the integrin tracer 68Ga-DOTA-A2B1 in the tumor lesions at all locations. The average tumor uptake and tumor-to-normal (T/N) ratio were 2.51 ± 0.56 %ID/g and T/N = 2.82, 3.40 ± 0.42 %ID/g and T/N = 1.52, and 1.58 ± 0.108 %ID/g and T/N = 2.31 in subcutaneous, orthotopic and osseous tumors, respectively (n = 5; p < 0.05). The xenograft tumors were all clearly visible. In contrast, the accumulation of 18F-FDG reached 3.6 ± 0.76 %ID/g, 1.39 ± 0.075 %ID/g and 3.78 ± 0.73 %ID/g in subcutaneous, orthotopic and osseous tumors, respectively (n = 5; p < 0.05). However, due to the high background uptake by normal tissue, the T/N values were less than or close to 1, making the tumors almost indistinguishable in the PET imaging analysis. Furthermore, 68Ga-DOTA-A2B1-PET imaging of the treated osseous tumor model demonstrated more than 19% tracer uptake in A549 lesions (1.72 ± 0.95 %ID/g vs. pretreatment 1.44 ± 0.12 %ID/g,p = 0. 015) 6 h post-treatment with doxorubicin. The elevated intensity of tracer uptake was in accordance with the results of in vitroWestern blot and ex vivo integrin staining, demonstrating elevated integrin α2β1 expression. CONCLUSION In this study, integrin α2β1 was identified as a biomarker of aggressive malignant NSCLC. Thus, efforts should be devoted to validating integrin α2β1 as a potential target for non-invasive diagnosis and as a predictive marker for monitoring treatment responses using a preclinical PET imaging system.

A poly[(R)-3-hydroxybutyrate] [P(3HB)]-degrading bacterium (strain JKCM-AJ-6,1α) was isolated from coastal seawater near the port of Yaizu, Suruga Bay, Japan. The strain grew well in a marine mineral medium supplemented with P(3HB) powder as the sole carbon source. Phylogenetic analysis revealed that the strain JKCM-AJ-6,1α belonged to the genus Shewanella . The isolate was unable to grow at temperatures above 50 °C, and the optimum range of growth temperatures was 30 °C–37 °C; however, the optimum temperature for degradation of P(3HB) was 15 °C. The maximum specific growth rate (μ = 1.0 h −1 ) was attained at a NaCl concentration of 0.2 M, but the strain was able to grow even in the presence of 0.8 M NaCl. This suggests that the strain is a typical marine bacterium. This is the first report showing P(3HB) depolymerase activity in a member of the genus Shewanella . It is concluded that the genus Shewanella may be one of the key bacterial groups involved in the P(3HB) cycle in marine environments.

Although hepatitis B virus (HBV) has been established to cause hepatocellular carcinoma (HCC), the exact mechanism remains to be clarified. Type II ground glass hepatocytes (GGHs) harbouring the HBV pre-S2 mutant large surface protein (LHBS) have been recognized as a morphologically distinct hallmark of HCC in the advanced stages of chronic HBV infection. Considering its preneoplastic nature, we hypothesized that type II GGH may exhibit high genomic instability, which is important for the carcinogenic process in chronic HBV carriers. In this study we found that pre-S2 mutant LHBS directly interacted with importin α1, the key factor that recognizes cargos undergoing nuclear transportation mediated by the importin α/β-associated nuclear pore complex (NPC). By interacting with importin α1, which inhibits its function as an NPC factor, pre-S2 mutant LHBS blocked nuclear transport of an essential DNA repair and recombination factor, Nijmegen breakage syndrome 1 (NBS1), upon DNA damage, thereby delaying the formation of nuclear foci at the sites of DNA double-strand breaks (DSBs). Pre-S2 mutant LHBS was also found to block NBS1-mediated homologous recombination repair and induce multi-nucleation of cells. In addition, pre-S2 mutant LHBS transgenic mice showed genomic instability, indicated by increased global gene copy number variations (CNVs), which were significantly higher than those in hepatitis B virus X mice, indicating that pre-S2 mutant LHBS is the major viral oncoprotein inducing genomic instability in HBV-infected hepatocytes. Consistently, the human type II GGHs in HCC patients exhibited increased DNA DSBs representing significant genomic instability. In conclusion, type II GGHs harbouring HBV pre-S2 mutant oncoprotein represent a high-risk marker for the loss of genome integrity in chronic HBV carriers and explain the complex chromosome changes in HCCs. Mouse array CGH raw data: GEO Accession No. GSE61378 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE61378).

Metabolic syndrome has closely linked to the development of human hepatocellular carcinoma (HCC). By using the hepatitis B virus (HBV) X (HBx) transgenic mouse model, we studied the dynamic evolution of serum and liver profiles of lipids and global cDNA expression at different stages of HBx tumorigenesis. We observed that the lipid (triglycerides, cholesterol, and fatty acids) profiles revealed a biphasic response pattern during the progression of HBx tumorigenesis: a small peak at early phase and a large peak or terminal switch at the tumor phase. By analyzing cDNA microarray data, the early peak correlated to the oxidative stress and pro-inflammatory response, which then resolved at the middle phase and were followed by the terminal metabolic switch in the tumor tissues. Five lipid metabolism-related genes, the arachidonate 5-lipoxygenase, lipoprotein lipase, fatty acid binding protein 4, 1-acylglycerol-3-phosphate O-acyltransferase 9, and apolipoprotein A-IV were identified to be significantly activated in HBx transgenic HCCs and further validated in human HBV-related HCCs. Inhibition of these lipid genes could reverse the effect of HBx on lipid biosynthesis and suppress HBx-induced cell proliferation in vitro. Our results support the concept that metabolic syndrome plays an important role in HBV tumorigenesis. The dysregulation of lipid metabolic genes may predict the disease progression to HCC in chronic hepatitis B patients. © 2015 Wiley Periodicals, Inc.

The development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) has been found to be associated with disturbed lipid metabolism. To elucidate the role of lipid metabolism in HBV tumorigenesis, we investigated the dynamic pattern of lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis. Lipid and gene expression profiles were analyzed in an in vitro culture system and in transgenic mouse livers harboring HBV pre-S2 mutant. The pre-S2 mutant transgenic livers showed a biphasic pattern of lipid accumulation, starting from mild fatty change in early (1 month) transgenic livers, which subsided and then, remarkably, increased in HCC tissues. This biphasic pattern was synchronized with ATP citrate lyase (ACLY) activation. Further analyses revealed that the pre-S2 mutant initiated an endoplasmic reticulum (ER) stress-dependent mammalian target of rapamycin (mTOR) signalling cascade. The pre-S2 mutant-induced mTOR signal activated the sterol regulatory element binding transcription factor 1 (SREBF1) to upregulate ACLY, which then activated the fatty acid desaturase 2 (FADS2), mediated through ACLY-dependent histone acetylation. Such an ER stress-dependent mTOR signal cascade also is important for the proliferation of hepatocytes in vitro and is further validated in HBV-related HCC tissues. IMPORTANCE Aberrations of lipid metabolism frequently occur in chronic HBV infection. Our results provide a potential mechanism of disturbed lipid metabolism in HBV pre-S2 mutant-induced tumorigenesis, which should be valuable for the design of HCC chemoprevention in high-risk HBV carriers.

The ability to early detect and assess the treatment response of recurrent and/or disseminated metastatic glioblastoma is critical for the effective management of this group of patients. Accumulating experimental evidence indicates that integrin α2β1 might be a prognostic biomarker for advanced phenotype of cancers. In this study, a novel (68)Ga-labeled integrin α2β1-targeted PET tracer (68)Ga-NOTA-PEG4-cyclo (GDGEAyK) ((68)Ga-A2B1) was designed and evaluated for the potential prognostic imaging of glioblastoma tumor in preclinical model. To prospectively verify the prognostic value of integrin α2β1, the in vitro Western blot and flow cytometry studies were performed to validate the integrin expression level of human glioblastoma (U87MG) cells. Extremely high expression level of integrin α2β1 justifies its role as a potential targeting marker. Thus, (68)Ga-A2B1 positron emission tomography was performed in subcutaneous U87MG tumor bearing athymic mice at 15 min postinjection after injection of 7-8MBq tracers. The receptor targeting specificity was confirmed in a competition blocking experiment. The tumor uptake of (68)Ga-A2B1 in the control and blockage groups was 1.57 ± 0.13 %ID/g (n = 3) and 0.96 ± 0.23 %ID/g** (n = 3), respectively. However, because of the quick renal washout rate and labile nature of peptide tracers in circulation conditions, the focus ultrasound (FUS) mediated delivery method was adopted to enhance tumor uptake and retention of tracers. To test the FUS delivery efficacy in vivo, three experimental arms were designed as follows: tumor bearing mice were administrated with (68)Ga-A2B1 only or microbubbles (MBs) with FUS treatment ((68)Ga-A2B1 + FUS + MBs) or embedded (68)Ga-A2B1-microbubbles ((68)Ga-A2B1-MBs + FUS) followed with FUS sonication. The average radioactivity accumulation within a tumor was quantified from the multiple region of interest volumes using the %ID/g value and was analyzed in accordance with the ex vivo autoradiographic and pathologic data. The significant tumor uptake in (68)Ga-A2B1 + FUS +MBs group (n = 6) and (68)Ga-A2B1-MBs + FUS group (n = 4) following FUS treatment were calculated as 2.25 ± 0.50 %ID/g* and 2.6 ± 0.49 %ID/g**, comparing with (68)Ga-A2B1 only group 1.48 ± 0.42 %ID/g (n = 10). These results suggest that there is significant difference in (68)Ga-A2B1 tumor uptake by FUS treatment either with or without tracer integration with microbubbles, which demonstrate a promising delivery strategy and critical multimodal setting for phenotyping imaging of aggressive glioma tumor. In conclusion, (68)Ga labeled (68)Ga-A2B1 allows noninvasive imaging of tumor-associated α2β1 expression and can be embedded in MB lipid shell for enhanced delivery and controlled release by sonoporation.

Microspheres can be prepared simply by the W 1 /O/W 2 double emulsion-solvent evaporation method. The glycerol density gradient method can be utilized with a homogenizer to produce and separate out homogenized microspheres, with the desired size. Flow cytometer is utilized to measure not only the uniformity of the size of microspheres but also analytical instruments are used to measure their release of drugs. The diameters of microsphere reached the 5 μm–10 μm range when they were prepared with 1% (w/v) P(3HB- co -5%3HV) at a homogenizer speed of 3000 rpm. The microspheres that were separated using the glycerin gradient method and extracted in the 25% concentration zone reveal the size homogeneity determined by flow cytometry analysis. The best microsphere degradation rates were approximately 80% after 72 h of enzyme degradation, as measured using a spectrophotometer, to elucidate the drug-releasing effect of the microspheres. The concentration of trypan blue in the supernatant fluid increased with the duration of the experiment. P(3HB- co -5%3HV)-prepared microspheres with diameters of around 10 μm were engulfed by cells in the cell culture experiments.

Background: Patients with chronic hepatitis B virus (HBV) infection are at a high risk to develop hepatocellular carcinoma (HCC). Recently, metabolic syndrome has been found to carry a risk for HCC development. Considering the limitation of chemotherapeutic drugs for HCCs, the development of chemopreventive agents for high risk chronic HBV carriers is urgently demanded. In this study, we used combined silymarin and resveratrol extract which have been shown to exhibit biologic effects on activating peroxisome proliferator activated receptors (PPAR) and inhibiting mTOR signaling in a transgenic mice model harboring HBV viral oncoproteins.Methods: The transgenic mice model harboring HBx and pre-S2 mutant constructs which develop HCC was adopted. First, we in vitro tested the ideal combination dosages of the silymarin and resveratrol product, and then we fed the natural product to the transgenic mice. The chemopreventive effects on preventing the development of HCC were evaluated.Results: MTT assay showed an enhanced effect of the combined silymarin and resveratrol product on the reduction of cell proliferation in two hepatoma cell lines, Huh-7 and Hep G2. In vitro reporter assay and Western blot analyses revealed that the combined product could activate PPAR/PGC-1α signaling and inhibit mTOR expression. In vivo, the combined products could significantly ameliorate fatty liver and reduce HCCs in transgenic mice harboring HBV oncoproteins.Conclusions: The combined silymarin and resveratrol product exhibits a synergistic effect on the reduction of HCC development in transgenic mice model and may represent a potential agent for the prevention of HCC in high risk chronic HBV carriers.Key words: HBV, HCC, Transgenic mice, Chemoprevention

Saikosaponin a (SSa) is one of the main active components of Bupleurum falcatum. It is commonly used to treat liver injury and fibrosis in traditional Chinese medicine. Our previous study showed that SSa induces apoptosis and inhibits the proliferation of rat hepatic stellate cell (HSC) line HSC-T6. The aim of the present study was to elucidate the mechanism of SSa-mediated apoptosis. Rat HSC cell line HSC-T6 and human HSC cell line LX-2 were used in this study. SSa triggered cell death mainly by apoptosis, as indicated by the typical morphological changes, sub-G1 phase of cell cycle increase, and activation of the caspase-9/caspase-3 cascade. In addition, SSa-induced apoptosis was partially inhibited by the caspase-3 inhibitor Z-DEVD-FMK, suggesting an involvement of caspase-3 dependent and independent pathways. Moreover, SSa upregulated pro-apoptotic proteins [BAK, Bcl-2-associated death promoter (BAD), and p53 upregulated modulator of apoptosis (PUMA)] and downregulated anti-apoptotic proteins (Bcl-2). In the mitochondria, SSa triggered the translocation of BAX and BAK from the cytosol to the outer membrane, resulting in a reduction of mitochondrial functions and membrane potential and subsequent release of apoptotic factors. Therefore, this study demonstrates that SSa induces apoptosis through the intrinsic mitochondrial-dependent pathway in HSCs.

PURPOSE: Growing evidence has demonstrated that aberrant expression of integrin α2β1 might contribute to the invasion, metastasis and drug resistance of non-small cell lung cancer (NSCLC). Thus, the integrin α2β1 targeting 68Ga-DOTA-A2B1 tracer was validated in NSCLC in contrast to accumulation of the clinically used 18F-FDG PET tracer to see if 68Ga-DOTA-A2B1-PET imaging can offer a valuable and critical diagnostic imaging criterion for the identification of phenotypes of aggressive lung cancer. METHODS: To verify the prognostic value of integrin α2β1, several quantitative and functional in vitro assays were validated in different NSCLC cell lines (CL1-0, CL1-5, A549 and selected A549++ cells). Positron emission tomography (PET) imaging studies using both standard 18F-FDG and a newly developed 68Ga-labeled integrin α2β1 (68Ga-DOTA-A2B1) tracer were sequentially performed on mice with lung tumor xenografts in different anatomic locations (subcutaneous, orthotopic and osseous) to validate the targeting capability of the 68Ga-DOTA-A2B1 tracers. Treatment responses were monitored by injecting animals with metastatic bone tumors with 5 mg/kg doxorubicin. All in vivo treatment responses in each treatment subgroup were monitored with a PET imaging system to evaluate the up-regulation of integrin expression at the earliest stage of treatment (6 h). RESULTS: The PET and computed tomography (CT) images from NSCLC xenograft animals unambiguously demonstrated accumulation of the integrin tracer 68Ga-DOTA-A2B1 in the tumor lesions at all locations. The average tumor uptake and tumor-to-normal (T/N) ratio were 2.51 ± 0.56 %ID/g and T/N = 2.82, 3.40 ± 0.42 %ID/g and T/N = 1.52, and 1.58 ± 0.108 %ID/g and T/N = 2.31 in subcutaneous, orthotopic and osseous tumors, respectively (n = 5; p < 0.05). The xenograft tumors were all clearly visible. In contrast, the accumulation of 18F-FDG reached 3.6 ± 0.76 %ID/g, 1.39 ± 0.075 %ID/g and 3.78 ± 0.73 %ID/g in subcutaneous, orthotopic and osseous tumors, respectively (n = 5; p < 0.05). However, due to the high background uptake by normal tissue, the T/N values were less than or close to 1, making the tumors almost indistinguishable in the PET imaging analysis. Furthermore, 68Ga-DOTA-A2B1-PET imaging of the treated osseous tumor model demonstrated more than 19% tracer uptake in A549 lesions (1.72 ± 0.95 %ID/g vs. pretreatment 1.44 ± 0.12 %ID/g,p = 0. 015) 6 h post-treatment with doxorubicin. The elevated intensity of tracer uptake was in accordance with the results of in vitroWestern blot and ex vivo integrin staining, demonstrating elevated integrin α2β1 expression. CONCLUSION: In this study, integrin α2β1 was identified as a biomarker of aggressive malignant NSCLC. Thus, efforts should be devoted to validating integrin α2β1 as a potential target for non-invasive diagnosis and as a predictive marker for monitoring treatment responses using a preclinical PET imaging system.

Background Saikosaponin d (SSd) is one of the main active triterpene saponins in Bupleurum falcatum. It has a steroid-like structure, and is reported to have pharmacological activities, including liver protection in rat, cell cycle arrest and apoptosis induction in several cancer cell lines. However, the biological functions and molecular mechanisms of mammalian cells under SSd treatment are still unclear. Methods The cytotoxicity and apoptosis of hepatic stellate cells (HSCs) upon SSd treatment were discovered by MTT assay, colony formation assay and flow cytometry. The collage I/III, caspase activity and apoptotic related genes were examined by quantitative PCR, Western blotting, immunofluorescence and ELISA. The mitochondrial functions were monitored by flow cytometry, MitoTracker staining, ATP production and XF24 bioenergetic assay. Results This study found that SSd triggers cell death via an apoptosis path. An example of this path might be typical apoptotic morphology, increased sub-G1 phase cell population, inhibition of cell proliferation and activation of caspase-3 and caspase-9. However, the apoptotic effects induced by SSd are partially blocked by the caspase-3 inhibitor, Z-DEVD-FMK, suggesting that SSd may trigger both HSC-T6 and LX-2 cell apoptosis through caspase-3-dependent and independent pathways. We also found that SSd can trigger BAX and BAK translocation from the cytosol to the mitochondria, resulting in mitochondrial function inhibition, membrane potential disruption. Finally, SSd also increases the release of apoptotic factors. Conclusions The overall analytical data indicate that SSd-elicited cell death may occur through caspase-3-dependent, caspase-3-independent and mitochondrial pathways in mammalian HSCs, and thus can delay the formation of liver fibrosis by reducing the level of HSCs.

Background Virus-associated haemophagocytic syndrome (VAHS) is a fatal complication of viral infections, such as Epstein–Barr virus and H5N1 influenza, that results from macrophage activation and proinflammatory cytokine injuries. The high comorbidity and mortality of current therapy urgently demands an ideal agent based on VAHS pathogenesis. Peroxisome proliferator activated receptor (PPAR) agonists, regulators of metabolic syndrome, can exhibit immunomodulatory effects on macrophage activation and cytokine secretion. Methods In this study, we adopted rosiglitazone, a PPAR-γ agonist, for VAHS control in a Herpesvirus papio (HVP)-infected rabbit model. Various doses of rosiglitazone were orally administered to rabbits on day 7 or day 20 after intravenous challenge with 5x107 copies of HVP. Results The rabbits that received 4 mg/day rosiglitazone had significantly increased survival when treated at an early stage of infection ( PConclusions PPAR agonists could represent a potentially new agent for the therapy of VAHS.

The radiation-induced graft polymerization of hydrophilic [sodium p-styrene sulfonate (SSS), acrylic acid (AAc)] and hydrophobic [styrene (St), methyl acrylate (MAAc)] monomers onto microbial poly(3-hydroxybutyrate) (PHB) powder was performed and the characteristics of the both grafting films obtained after remolding were compared. The grafting of various monomers onto the PHB powder increased with reaction time. The degree of grafting (Xg) onto the PHB by these various monomers followed the order St, SSS, MAAc and AAc. The PHB films onto which were grafted St, SSS, MAAc and AAc were characterized by measuring the contact angle, the adsorption of enzyme PHB depolymerase, and the biodegradability, as well as by differential scanning calorimetry. Both hydrophobic and hydrophilic monomers affected the contact angle of grafted PHB film with St, SSS, MAAc and AAc monomers. However, the adsorption of enzyme on the grafted PHB film increased with the amount of hydrophilic monomer and degree of grafting. Consequently, the enzyme PHB depolymerase easily approached the PHB film when the hydrophilic groups were grafted onto its surface. The enzymatic degradation of grafted PHB films with hydrophilic monomer proceeded more quickly than that of hydrophobic monomers.

This study discusses poly(3-hydroxybutyrate- co -4-hydroxybutyrate) that is produced by Delftia acidovorans bacteria in fed-batch cultures from various carbon sources. The experimentally determined optimal fed-batch culture conditions are as follows: pH: 7.0, incubation temperature: 26 °C, incubation time: 72 h, and concentration of carbon source: 10 g/L. The maximum 4HB unit composition of P(3HB- co -4HB) obtained using the fed-batch culture with a cell concentration of about 2.5 g/L was 94 mol% although the P(3HB- co -4HB) content remained low, at around 13 wt%. The extent of the enzymatic degradation of P(3HB- co -4HB) was determined by involved PHB depolymerase and lipase. The tensile strength of P(3HB- co -4HB) markedly decreased during 2 h of degradation by PHB depolymerase, whereas that of P(3HB- co -4HB) degraded by lipase for 50 h was at least 3 MPa.

Epstein-Barr virus (EBV) can infect T lymphocytes and manifests as hemophagocytic lymphohistiocytosis (HLH), a distinct entity of hemophagocytic syndrome (HPS) characterized by fever, hepatosplenomegaly, cytopenia, hypercytokinemia, and systemic macrophage activation with hemophagocytosis. In a substantial percentage of HLH patients, the disease may relapse or progress to T-cell lymphoma in months to years. In the present review, the authors summarize the previous studies on the pathogenesis of HLH and the potential mechanism for the progression of disease from HLH to T-cell lymphoma. The infection of T cells by EBV could activate T cells to secrete proinflammatory cytokines, particularly tumor necrosis factor-alpha (TNF-alpha), which subsequently activate macrophages. EBV latent membrane protein-1 (LMP-1) is the viral product responsible for the activation of the TNF receptor (TNFR) associated factors/nuclear factor-kappaB (NF-kappaB)/ERK pathway to enhance cytokine secretion mediated through the suppression of the SAP/SH2D1A gene. The activation of NF-kappaB will confer resistance to TNF-alpha-induced apoptosis on EBV-infected T cells through the down-regulation of TNFR-1. Consistent with in vitro observations, EBV-associated T or natural killer/T-cell lymphoma showed constitutive activation of NF-kappaB, explaining its drug resistance, hypercytokinemia, and poor prognosis. Therefore, similar to other inflammation-associated cancers, HLH provides a unique model to study the mechanism of disease progression from a benign virus-infected disorder (HLH) to T-cell lymphoma. Inhibition of the NF-kappaB signal pathway should provide a potential target for the treatment of HLH and EBV-associated T-cell lymphoma.

This research studies the morphology and characterization of three-dimensional (3D) micro-porous structures produced from biodegradable chitosan for use as scaffolds for cells culture. The chitosan 3D micro-porous structures were produced by a simple liquid hardening method, which includes the processes of foaming by mechanical stirring without any chemical foaming agent added, and hardening by NaOH cross linking. The pore size and porosity were controlled with mechanical stirring strength. This study includes the morphology of chitosan scaffolds, the characterization of mechanical properties, water absorption properties and in vitro enzymatic degradation of the 3D micro-porous structures. The results show that chitosan 3D micro-porous structures were successfully produced. Better formation samples were obtained when chitosan concentration is at 1-3%, and concentration of NaOH is at 5%. Faster stirring rate would produce samples of smaller pore diameter, but when rotation speed reaches 4000 rpm and higher the changes in pore size is minimal. Water absorption would reduce along with the decrease of chitosan scaffolds' pore diameter. From stress-strain analysis, chitosan scaffolds' mechanical properties are improved when it has smaller pore diameter. From in vitro enzymatic degradation results, it shows that the disintegration rate of chitosan scaffolds would increase along with the processing time increase, but approaching equilibrium when the disintegration rate reaches about 20%.

The infection of T cells by Epstein-Barr virus (EBV) may result in hemophagocytic syndrome (HPS) through enhanced cytokine secretion, particularly tumor necrosis factor-α (TNF-α), by EBV latent membrane protein-1 (LMP-1). One bewildering observation of HPS patients is relapsing disease or progression to T-cell lymphoma. This finding raises the question whether EBV LMP-1-expressing T cells may survive and proliferate in the cytokine milieu of HPS. To explore this possibility, we tested the sensitivity of LMP-1-expressing T cells to apoptosis in the presence of TNF-α. LMP-1 up-regulated TNF-α through TRAF2,5 and nuclear factor-κB pathway in T cells. The LMP-1-expressing T cells then became resistant to TNF-α-induced apoptosis. Interestingly, the expression of TNFR1 was remarkably down-regulated by LMP-1 in T cells. Furthermore, the TNF-α/TNFR1 downstream death signal TNFR1-associated death domain protein was constitutively recruited by LMP-1, and the activities of apoptotic caspases 3, 8, and 9 were suppressed. Reconstitution of TNFR1 successfully reversed the TNF-α-induced apoptotic cascades. Therefore, EBV LMP-1 not only activates T cells to proliferate but also confers resistance to TNF-α-mediated apoptosis via down-regulation of TNFR1 in the cytokine milieu of HPS. This finding provides a potential mechanism to explain the disease persistence or progression to T-cell lymphoma in HPS patients.

Solution-grown single crystals of poly(ethylene succinate-co-trimethylene succinate)s (PETSA) were hydrolyzed by polyhydroxybutyrate (PHB) depolymerase from Ralstonia pickettii T1. Enzymatic degradation proceeded from the edges of the lamellar crystals, yielding serrated contours and small crystal fragments. On the other hand, single PETSA crystals were aminolyzed in 20 % aqueous methylamine solution to remove the folded chain regions, and enzymatically degraded using PHB depolymerase to remove poly(trimethylene succinate)—PTSA—components at the surfaces of single aminolyzed crystals. It was found that a small amount of PTSA component could be incorporated into the poly(ethylene succinate)—PESA—mother crystal lattice irrespective of the PTSA content.

Hepatitis B virus (HBV) pre-S2 mutant can induce hepatocellular carcinoma (HCC) via the induction of endoplasmic reticulum stress to activate mammalian target of rapamycin (MTOR) signaling. The association of metabolic syndrome with HBV-related HCC raises the possibility that pre-S2 mutant-induced MTOR activation may drive the development of metabolic disorders to promote tumorigenesis in chronic HBV infection. To address this issue, glucose metabolism and gene expression profiles were analyzed in transgenic mice livers harboring pre-S2 mutant and in an in vitro culture system. The pre-S2 mutant transgenic HCCs showed glycogen depletion. The pre-S2 mutant initiated an MTOR-dependent glycolytic pathway, involving the eukaryotic translation initiation factor 4E binding protein 1 (EIF4EBP1), Yin Yang 1 (YY1), and myelocytomatosis oncogene (MYC) to activate the solute carrier family 2 (facilitated glucose transporter), member 1 (SLC2A1), contributing to aberrant glucose uptake and lactate production at the advanced stage of pre-S2 mutant transgenic tumorigenesis. Such a glycolysis-associated MTOR signal cascade was validated in human HBV-related HCC tissues and shown to mediate the inhibitory effect of a model of combined resveratrol and silymarin product on tumor growth. Our results provide the mechanism of pre-S2 mutant-induced MTOR activation in the metabolic switch in HBV tumorigenesis. Chemoprevention can be designed along this line to prevent HCC development in high-risk HBV carriers.

This research uses modified orifice method to prepare the O/W type Chitosan encapsulated volatile Citronella Oil microcapsules. In this article, we investigated the forming condition of microcapsules and the influence to sustained release effect of volatile Citronella Oil by applying thermal pretreatment to microcapsules. The results suggest that the forming of microcapsules should be processed under the fundamental conditions of: (1) the concentration of Chitosan is at least 0.2wt%, (2) NaOH is greater than 0.1wt%, and (3) with the additive of coconut oil as natural surfactant, so that we could obtain final product of microcapsules with better formation and dispersion. The changes in concentration of Chitosan will affect the encapsulation efficiency of the volatile Citronella Oil. When the concentrations of Chitosan are 0.5%, 1.0% and 1.5%, the encapsulation efficiencies are 98.2%, 95.8% and 94.7%, respectively. The particle size of Chitosan microcapsules would decrease as the emulsification stirring speed increases. When the stirring speeds are 400 rpm, 800 rpm, and 1500 rpm, the average particle sizes of microcapsules produced are 225+/-24 microm, 131+/-20 microm, and 11+/-3 microm, respectively. If the microcapsules were thermal pretreated at 80 degrees C, the structure of Chitosan wall membrane would shrink and thus achieve the effect of sustained release. The sustaining effect would increase along with treatment time increases.

Solution-grown single crystals of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] were hydrolyzed by polyhydroxybutyrate (PHB) depolymerase from Ralstonia pickettii T1. Enzymatic degradation proceeded from the edges of lamellar crystals, yielding serrated contour and small crystal fragments. Gel permeation chromatography analysis revealed that the molecular weights of the crystals decreased during enzymatic degradation, suggesting that the enzymatic hydrolysis of chain-folding regions at the crystal surfaces occurred in addition to the enzymatic degradation at crystal laterals or edges. After P(3HB-co-4HB) single crystals were aminolysed in 20% aqueous methylamine solution to remove the folded-chain regions and enzymatic degradation by lipase from Rhizopus oryzae to remove 4HB components at crystal surfaces of single crystal aminolyzed, it was found that a small amount (up to ca. 2 mol%) of 4HB component can be incorporated into the P(3HB) mother crystal lattice irrespective of the 4HB content.

We previously discovered a hamster monoclonal antibody, TAB4, against mouse PSGL-1/CD162 that can induce death of activated T cells. Here, we further investigated the potential of TAB4 in treating two murine models of T cell-mediated diseases. The results showed that administration of TAB4 suppressed incidence and severity of both GVHD and type I diabetes. Analyses of apoptotic T cells ex vivo shortly after antibody injection revealed a higher percentage of apoptosis among activated T cells in the TAB4-treated group than in the control group. Furthermore, restoration of functional donor T cells was observed in TAB4-treated mice. As TAB4 does not affect the binding of P-selectin to activated T cells, our data suggest that its long-lasting therapeutic effect on inhibiting disease progression is attained by specifically inducing apoptosis of activated T cells. These data hence extend our previous finding of the novel property of PSGL-1 and strongly indicate that the PSGL-1-specific apoptosis-inducing antibody is a new therapeutic agent possessing a great potential for controlling GVHD and other T cell-mediated autoimmune diseases.

Delftia acidovorans (IFO13582) was grown in fed-batch and chemostat cultures with n-butyric acid and 1,4-butanediol as mixed carbon substrates. In fed-batch cultures, the synthesis rate of the polymer was considerably increased with the increment of the cell growth. The polymer content increased and reached to a maximum of 27 wt% with increasing the cell dry-weight of ca. 4.4-5.2 g/l at 26 °C for 72 h and the maximum 4HB unit composition of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] was slightly low value of ca. 66 mol%. Whereas the maximum 4HB unit composition of P(3HB-co-4HB) obtained by the fed-batch culture with lower cell concentration of ca. 2.5 g/l reached to 94 mol% though the content of P(3HB-co-4HB) was always low, at ca. 13 wt%.

Metabolic syndrome has closely linked to the development of human hepatocellular carcinoma (HCC). By using the hepatitis B virus (HBV) X (HBx) transgenic mouse model, we studied the dynamic evolution of serum and liver profiles of lipids and global cDNA expression at different stages of HBx tumorigenesis. We observed that the lipid (triglycerides, cholesterol, and fatty acids) profiles revealed a biphasic response pattern during the progression of HBx tumorigenesis: a small peak at early phase and a large peak or terminal switch at the tumor phase. By analyzing cDNA microarray data, the early peak correlated to the oxidative stress and pro-inflammatory response, which then resolved at the middle phase and were followed by the terminal metabolic switch in the tumor tissues. Five lipid metabolism-related genes, the arachidonate 5-lipoxygenase, lipoprotein lipase, fatty acid binding protein 4, 1-acylglycerol-3-phosphate O-acyltransferase 9, and apolipoprotein A-IV were identified to be significantly activated in HBx transgenic HCCs and further validated in human HBV-related HCCs. Inhibition of these lipid genes could reverse the effect of HBx on lipid biosynthesis and suppress HBx-induced cell proliferation in vitro. Our results support the concept that metabolic syndrome plays an important role in HBV tumorigenesis. The dysregulation of lipid metabolic genes may predict the disease progression to HCC in chronic hepatitis B patients.

Lead (Pb) and lipopolysaccharide (LPS) affect not only neurons but also glial cells, and cause neurological impairment in the brain. We have previously shown an enhancement of tumor necrosis factor-alpha (TNF-alpha) in U-373MG glial cells after exposure of Pb and LPS. To determine whether Pb- or LPS-induced TNF-alpha triggers glial cell death, the apoptotic response was investigated in glial cells both in vitro and in vivo. In vitro, Pb ranging from 0.1 to 10 microM increased the expression of TNF-alpha in a dose-dependent manner in U-373MG cells. Similarly, LPS (500 ng/ml) stimulated TNF-alpha expression in the same cells. A combination of LPS and Pb did not cause higher mRNA TNF-alpha expression than LPS or Pb alone. However, exposure to Pb and LPS did not affect apoptosis in U-373MG cells detected by flow cytometric analysis with merocyanine 540 staining and propidium iodine staining. In B6 mice, glial cells in the brain were immunostained positive for TNF-alpha after an intraperitoncal administration of Pb (12.5 mg/kg) or LPS (10 mg/kg). Consistent with the findings in the cell culture system, few apoptotic cells were detected in glial and neurons by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) in the brain of B6 mice. We conclude that induction of TNF-alpha alone by Pb and LPS does not cause cell apoptosis in cells of glial origin.

The composition and dyad sequence distributions of bacterially synthesized copolymers of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) P(3HB-co-4HB) have been studied by means of high-resolution 1H-, 13C-NMR spectroscopy and differential scanning calorimetry. These biodegradable copolyesters are mixtures of copolymers having different 4HB contents. The fractionation was carried out to obtain fractionated copolymers having narrower compositional distribution. The dyad sequence distributions of P(3HB-co-4HB) measured by NMR shows close to block copolymer in lower 4HB content side, whereas in higher 4HB content side, the that of P(3HB-co-4HB) indicates statistically random copolymer. The heat of fusion of P(3HB) and P(4HB) was estimated using Flory's equation. The values of heat of fusion of P(3HB) and P(4HB) measured were 1490 cal/mol and 2484 cal/mol. The values of number-average sequence lengths calculated from NMR and DSC show the P(3HB-co-4HB) copolymer including long continuous sequence in lower and higher 4HB content side.

The bulk crystallization behavior of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] were studied using polarized light microscopy, differential scanning calorimetry, and wide- and small-angle X-ray diffraction. Under the isothermal crystallization condition, the linear growth rates of the P(3HB-co-4HB) spherulites were measured at various temperatures and the influence of mutual disturbance for both comonomer components was clarified. The long period of P(3HB-co-4HB) increased much less with an increase in the crystallization temperature, compared to that of P(3HB). These results imply that the P(3HB) crystal excluded the 4HB component when, for example, the content of 4HB component in the copolymer was 5 mol%.

Although hepatitis B virus (HBV) has been established to cause hepatocellular carcinoma (HCC), the exact mechanism remains to be clarified. Type II ground glass hepatocytes (GGHs) harbouring the HBV pre-S2 mutant large surface protein (LHBS) have been recognized as a morphologically distinct hallmark of HCC in the advanced stages of chronic HBV infection. Considering its preneoplastic nature, we hypothesized that type II GGH may exhibit high genomic instability, which is important for the carcinogenic process in chronic HBV carriers. In this study we found that pre-S2 mutant LHBS directly interacted with importin α1, the key factor that recognizes cargos undergoing nuclear transportation mediated by the importin α/β-associated nuclear pore complex (NPC). By interacting with importin α1, which inhibits its function as an NPC factor, pre-S2 mutant LHBS blocked nuclear transport of an essential DNA repair and recombination factor, Nijmegen breakage syndrome 1 (NBS1), upon DNA damage, thereby delaying the formation of nuclear foci at the sites of DNA double-strand breaks (DSBs). Pre-S2 mutant LHBS was also found to block NBS1-mediated homologous recombination repair and induce multi-nucleation of cells. In addition, pre-S2 mutant LHBS transgenic mice showed genomic instability, indicated by increased global gene copy number variations (CNVs), which were significantly higher than those in hepatitis B virus X mice, indicating that pre-S2 mutant LHBS is the major viral oncoprotein inducing genomic instability in HBV-infected hepatocytes. Consistently, the human type II GGHs in HCC patients exhibited increased DNA DSBs representing significant genomic instability. In conclusion, type II GGHs harbouring HBV pre-S2 mutant oncoprotein represent a high-risk marker for the loss of genome integrity in chronic HBV carriers and explain the complex chromosome changes in HCCs. Mouse array CGH raw data: GEO Accession No. GSE61378 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE61378).

Poly(3-hydoxybutyrate- co -4-hydroxybutyrate) [P(3HB- co -4HB)] was biosynthesized by Comamonas acidovorans with mixed carbon sources of n -butyric acid and 1,4-butanediol. P(3HB) and P(3HB- co -94 mol% 4HB) were obtained by fermentation with sole carbon source of n -butyric acid and 1,4-butanediol, respectively. The content of 4HB component in P(3HB- co -4HB) increased as the composition of 1,4-butanediol in mixed carbon sources increased. These biosynthesized copolymers are not homogeneous, but mixtures of copolymers having different 4HB contents. Fractionation was carried out to obtain fractionated copolymers having a narrower distribution of composition. The change in structural and physical properties of the fractionated copolymers were investigated against the 4HB contents. Crystallinities of P(3HB- co -4HB)s were estimated using density values and the heat of fusion of P(3HB) measured was 125 J g −1 and that of P(4HB) was 76 J g −1 .

Hepatitis B virus (HBV) X protein (HBx) and pre-S2 deletion mutant large surface antigens are oncoproteins that induce hepatocellular carcinoma (HCC). The interaction of these two oncoproteins in hepatocytes and its significance in tumorigenesis remain to be elucidated. In this study, we observed the co-expression of HBx with surface antigens in ground-glass hepatocytes in 5 of 20 hepatitis B surface antigen-positive livers. In vitro, hepatocytes co-expressing HBx and a pre-S2 mutant showed enhanced expression of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin signals. Transgenic mice harboring both HBx and pre-S2 mutant construct plasmids developed HCCs at an average of 15.1 months, earlier than animals carrying either HBx (16.9 months) or pre-S2 mutant (24.5 months) alone. The oncogenic signals of vascular endothelial growth factor-A, phosphorylated Akt 1/2/3, phosphorylated extracellular signal-regulated kinase 1/2, and phosphorylated mammalian target of rapamycin were sequentially and differentially activated at different stages in tumorigenesis. Phosphorylated mTOR was consistently activated in transgenic and human HCCs. We conclude that ground-glass hepatocytes co-expressing HBx and surface antigens exhibit enhanced oncogenic effects and tumorigenesis in chronic HBV infections. The mTOR signal cascade may be the key regulator in HBV tumorigenesis and may be useful targets in the design of HCC therapy.

Chronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). The pre-S(2) mutant large HBV surface antigen (LHBS) in type II ground glass hepatocytes (GGHs) has been recognized as an emerging viral oncoprotein; it directly interacts with the c-Jun activation domain-binding protein 1 (JAB1) and subsequently causes hyperphosphorylation of the tumor-suppressor retinoblastoma and, consequently, leads to disturbed cell cycle progression. The interaction of the pre-S(2) mutant LHBS with JAB1 could provide a potential target for chemoprevention. In this study, we found that the preneoplastic type II GGHs showed a significant decrease of the cyclin-dependent kinase inhibitor p27(Kip1), which serves as a marker for pre-S(2) mutant-JAB1 complex formation. The histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) elevated expression of the tumor-suppressor thioredoxin-binding protein 2 (TBP2), which subsequently enhanced the JAB1-TBP2 interaction and abolished the pre-S(2) mutant LHBS-induced degradation of p27(Kip1), which, in turn, recovered the normal cell cycle checkpoint. The pre-S(2) mutant LHBS-induced pro-oncogenic effects: increased cell proliferation, nuclear/cytoplasmic ratio and proliferating cell nuclear antigen expression, were all greatly ameliorated after SAHA treatments, which suggested SAHA as a promising chemopreventive agent for the pre-S(2) mutant oncoprotein-induced HCC. In conclusion, this study provides the mechanism of histone deacetylase (HDAC) inhibitor in preventing the pre-S(2) mutant-induced oncogenic phenotype. The HDAC inhibitor SAHA is therefore a potential chemopreventive agent for high-risk chronic HBV patients who may develop HCC.

IgA is the most abundant antibody in mammals. However, the mechanism of its class switching is still not clear. The formation of the R-loops, as the target for AID, has been proposed to play a crucial role during mammalian class switch recombination. Here, we provide a systematic evaluation of R-loops at Sα (IgA) in CH12F3-2A cells, which is a unique cell model system for class switch recombination because of its consistent switching to IgA upon stimulation. The results of R-loop analysis demonstrate distinct features specific to Sα. Some R-loops may initiate from the end of Iα, but all terminate exclusively within Sα. Time-course analysis also indicates that the percentage of R-loops peaks prior to the occurrence of class switch recombination. This is the first demonstration that R-loops form at Sα in vitro and in situ, despite variable G density and relatively few GGGG clusters in Sα. The short distance from the promoter to Sα may compensate for the less robust R-loop-forming factors at Sα relative to other switch regions. In conclusion, R-loops at the Sα region further support R-loop formation as a general feature of all stimulated switch regions.

In this investigation, biodegradable polymer poly(L-lactic acid) (PLA) microspheres were prepared by the W(1)/O/W(2) solvent evaporation method. The inner phase was aqueous solution (W(1)) that contained bovine serum albumin that was labeled with fluorescein isothiocyanate (FITC-BSA). PLA was dissolved in chloroform with emulsifier sorbitan monooleate (span 80) as the dispersed phase (O). These two solutions (W(1)/O) were emulsified by a homogenizer to form a primary emulsion. Polyvinyl alcohol (PVA) used as surfactant, was applied in the formation of microspheres (W(2)). 0.5% (w/v) PLA was stirred at 3000 rpm using a homogenizer. Microspheres with sizes of up to around 10 μm were produced. These microspheres were separated by the glycerol gradient method, and take microspheres at part of 25% glycerol gradient concentration was analyzed by flow cytometry, indicating a more homogeneous particle size distribution than that not separated. The microspheres were degraded using several enzymes, and around 40% was degraded by 72 h. This result reveals the effectiveness of drug delivery by PLA microspheres, which was evaluated by performing a drug release test and flow cytometric analysis. The FITC-BSA concentration in the supernatant increased with the experimental time. At the phagocytosis experiments, encapsulated with FITC-BSA drug of microspheres can be used by the cell, as particle size approximately 1 μm.

Haemophagocytic lymphohistiocytosis (HLH) is a fatal haematological disorder with diverse aetiology. This prospective study was undertaken to characterize HLH cases in Vietnamese children. Clinical and laboratory data, genetic analyses and outcome of the HLH patients were analysed. A total of 33 patients were enrolled from March 2007 to December 2008, with a median age of 3 years. Mutations of the SH2D1A (SAP) and PRF1 genes were detected in one patient, respectively. The virus association was high, up to 63.6% (21/33), including Epstein-Barr virus (19/33), cytomegalovirus (2/33) and dengue virus (2/33). Five patients had malignant lymphoma and two had autoimmune diseases. Twenty-eight patients were treated according to the HLH-2004 protocol. The first response rate was 64.3% (18/28), with an early death rate of 35.7% (10/28). High levels of interferon-gamma, interleukin-10, MIG and interferon-inducible protein-10 (IP-10) were associated with early mortality (P < 0.05). Reactivation among the responders was high (9/18) and the uneventful resolution was low (3/18) after a median follow-up of 35 weeks. In conclusion, the majority of HLH cases are associated with virus infections in Vietnamese children. Familial HLH is rare. The frequent reactivation and high mortality demands a more appropriate therapeutic regimen in tropical areas like Vietnam.