Bracovirus Sneaks Into Apoptotic Bodies Transmitting Immunosuppressive Signaling Driven by Integration-Mediated eIF5A Hypusination

A typical characteristics of polydnavirus (PDV) infection is a persistent immunosuppression, governed by the viral integration and expression of virulence genes. Recently, activation of caspase-3 by Microplitis bicoloratus bracovirus (MbBV) to cleave Innexins, gap junction proteins, has been highlighted, further promoting apoptotic cell disassembly and apoptotic body (AB) formation. However, whether ABs play a role in immune suppression remains to be determined. Herein, we show that ABs transmitted immunosuppressive signaling, causing recipient cells to undergo apoptosis and dismigration. Furthermore, the insertion of viral–host integrated motif sites damaged the host genome, stimulating eIF5A nucleocytoplasmic transport and activating the eIF5A-hypusination translation pathway. This pathway specifically translates apoptosis-related host proteins, such as P53, CypA, CypD, and CypJ, to drive cellular apoptosis owing to broken dsDNA. Furthermore, translated viral proteins, such Vank86, 92, and 101, known to complex with transcription factor Dip3, positively regulated DHYS and DOHH transcription maintaining the activation of the eIF5A-hypusination. Mechanistically, MbBV-mediated extracellular vesicles contained inserted viral fragments that re-integrated into recipients, potentially via the homologous recombinant repair system. Meanwhile, this stimulation regulated activated caspase-3 levels via PI3K/AKT 308 and 473 dephosphorylation to promote apoptosis of granulocyte-like recipients Sf9 cell; maintaining PI3K/AKT 473 phosphorylation and 308 dephosphorylation inhibited caspase-3 activation leading to dismigration of plasmatocyte-like recipient High Five cells. Together, our results suggest that integration-mediated eIF5A hypusination drives extracellular vesicles for continuous immunosuppression.

Microplitis bicoloratus bracovirus modulates innate immune suppression through the eIF4E-eIF4A axis in the insect Spodoptera litura

Eukaryotic initiation factor 4E (eIF4E) is regulated during the innate immune response. However, its translational regulation under innate immune suppression remains largely unexplored. Microplitis bicoloratus bracovirus (MbBV), a symbiotic virus harbored by the parasitoid wasp, Microplitis bicoloratus, suppresses innate immunity in parasitized Spodoptera litura. Here, we generated eIF4E dsRNA and used it to silence the eIF4E gene of S. litura, resulting in a hallmark immunosuppressive phenotype characterized by increased apoptosis of hemocytes and retardation of head capsule width development. In response to natural parasitism, loss of eIF4E function was associated with similar immunosuppression, and we detected no significant differences between the response to parasitism and treatment with eIF4E RNAi. Under MbBV infection, eIF4E overexpression significantly suppressed MbBV-induced increase in apoptosis and suppressed apoptosis to the same extent as co-expression of both eIF4E and eIF4A. There were no significant differences between MbBV-infected and uninfected larvae in which eIF4E was overexpressed. More importantly, in the eIF4E RNAi strain, eIF4A RNAi did not increase apoptosis. Collectively, our results indicate that eIF4E plays a nodal role in the MbBV-suppressed innate immune response via the eIF4E-eIF4A axis.

[The expressions of CTLA-4 and PD-1 on CD(4)(+) T cells and the level of plasma VEGF in patients with obstructive sleep apnea hypopnea syndrome]

Objective: CD(4)(+)T cells, cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death-1 (PD-1) and vascular endothelial growth factor (VEGF) are associated with cancer development. The aim of the present study was to investigate the expression of CTLA-4, PD-1 and VEGF in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods: From January 2017 to January 2018, a total of 47 first-visit outpatients were recruited in the Sleep and Respiratory Disorder Center of Guangdong Provincial People's Hospital, and were divided into control group (N=17, mean age 54±12 years), mild-to-moderate OSAHS group (N=15, mean age 54±12 years) and severe OSAHS group (N=15, mean age 56±13 years). Venous blood was collected, plasma and cells were isolated, the expressions of PD-1 and CTLA-4 on the surface of CD(4)(+)T cells were detected by flow cytometry, and plasma VEGF was measured by enzyme linked immunosorbent assay. Results: The proportion of CD(4)(+)T cells in control group, mild-to-moderate OSAHS group and severe OSAHS group were respectively(38±8)%, (35±8)% and (38±6)% (F=1.228, P>0.05). The expression of CTLA-4 on CD(4)(+)T cells were respectively [1.13 (0.59~1.78)]%, [0.45 (0.16~1.43)]% and [0.87(0.47~1.46)]% (H=2.205, P>0.05). The expression of PD-1 on CD(4)(+)T cells were respectively [4.24 (2.12~6.03)]%, [3.54(2.69~5.09)]% and [3.31(1.67~8.25)]% (H=0.541, P>0.05). The concentrations of VEGF in control group, mild-to-moderate OSAHS group and severe OSAHS group were statistically different [(395.16±87.78) ng/L vs (452.85±107.97) ng/L vs (546.42±199.27) ng/L, F=4.827, P=0.013]. Compared with the control group, VEGF concentration was significantly increased in the severe OSAHS group(P<0.01). VEGF concentration was correlated negatively with the lowest SpO(2) (r (s)=-0.480,P=0.001), but positively with apnea-hypopnea index(r (s)=0.403, P=0.005), oxygen desaturation index (r (s)=0.378, P=0.010) and proportion of SpO(2) less than or equal to 90% of total sleep time(r (s)=0.547, P=0.000 3). Conclusion: There was no significant difference of PD-1 and CTLA-4 expression on CD(4)(+)T cells in patients with and without OSAHS. The expression of VEGF was elevated in OSAHS patients, and increased with the severity of OSAHS and hypoxia.

Stature Estimation of Sichuan Han Females Based on X-ray Photography of Total Lower Limbs

OBJECTIVES

To establish a mathematical model of stature estimation for Sichuan Han females on the basis of the relationship between lower limbs and individual height, thus to provide evidence for forensic identification.

METHODS

Samples were collected from 171 Sichuan Han females. Large flat panel multi-function digital photography system was used to take the full-body X-ray films of the lower limbs. Indexes of long bones and stature of the subjects were measured, respectively. A linear regression analysis was carried out on the correlation between them, and a mathematical model of the stature calculation was established. Then the mathematical model was used to calculate the stature of another 29 Sichuan Han females to test its accuracy.

RESULTS

The maximum length of femur （x₁） had the highest correlation with stature. A total of 13 linear regression equations were established （P<0.05）, with the correlation coefficient （R） 0.821-0.897 and the standard error of the estimation （SEE） 2.994-3.812 cm. The backtesting showed that the equation y=41.604+1.205 x₁+1.318 x₆+2.444 x₁₂+1.852 x₁₃-2.388 x₁₄ had the smallest mean absolute deviation （2.485 years old） and the highest accuracy of ±2SEE （92.9%）, and that the equation y=48.783+2.568 x₁ had the highest accuracy of ±1SEE （60.7%）.

CONCLUSIONS

The stature estimation is high by using the long bones of the lower limbs has high accuracy.

A secreted-Cu/Zn superoxide dismutase from Microplitis bicoloratus reduces reactive oxygen species triggered by symbiotic bracovirus

In the parasitoid/polydnavirus/host system, polydnaviruses protect larva development in the host hemocoel by suppressing the host immune response. However, the negative effects on the parasitoid and the strategy of the parasitoid to deal with this disadvantage are still unknown. Microplitis bicoloratus bracovirus induces granulocyte apoptosis to suppress immune responses, resulting in an apoptotic haemolymph environment in which immature M. bicoloratus larva develop. Here, we determined the transcriptional profiles of immature M. bicoloratus across five time-points throughout the immature developmental process from egg to third instar. Dynamic gene expression pattern analysis revealed clear rapid changes in gene expression characteristic of each developmental stage, indicating faster sequential unambiguous functional division during development. Combined with the proteome of the host haemolymph, immature parasitoids likely secreted a Cu/Zn superoxide dismutase to reduce reactive oxygen species generation by symbiotic bracovirus. These data established a basis for further studies of parasitoid/host interactions and identified a novel positive self-protection mechanism for the parasitoid.

[Stature Estimation for Sichuan Han Female Based on Whole-spine X-ray Photo- graphy]

OBJECTIVES

To establish regression models of stature estimation for Sichuan Han female by the measurement of total vertebral column length in the frontal and lateral X-ray films of whole-spine.

METHODS

The frontal and lateral X-ray films of whole-spine were collected from 200 Sichuan Han females by large flat-panel multi-functional universal radiography and fluoroscopy system. The data and mean values of frontal and lateral total vertebral column length were measured and calculated in all the samples, respectively. The relationship of combined multi-markers and stature were analysed by linear regression analysis, and the mathematical models of stature estimation were established. The data of 30 new samples were selected and inputted for verifying the accuracy of the mathematical models.

RESULTS

The total vertebral column length showed a good correlation with stature, and the mean values of the frontal and lateral X-ray films of total vertebral column length had the highest correlation coefficients. Three established linear regression equation models were statistically significant （P<0.05）, and the equation established with lateral total vertebral column length showed the highest accuracy.

CONCLUSIONS

The stature estimation by the measurement of total vertebral column length has high accuracy.

Inhibition of translation initiation factor eIF4A is required for apoptosis mediated by Microplitis bicoloratus bracovirus

Apoptotic hemocytes induced by Microplitis bicoloratus parasitism have been reported, and M. bicoloratus bracovirus (MbBV) is known to be the apoptosis inducer. However, the mechanism how MbBV regulates apoptosis remains unclear. eIF4A, one of translation initiation factors, was found from a Spodoptera litura transcriptome, the expression of which in the parasitized hemocytes of S. litura was inhibited in RT-qPCR analysis. The western blot also illustrated eIF4A at 6-day post-parasitization was inhibited in hemocytes. For testing interaction of MbBV-eIF4A-apoptosis, a cDNA clone encoding 1,266 bp of eIF4A was obtained from S. litura hemocytes and sequenced. Then, a 48 kDa V5-fusion protein of the eIF4A was detected by using the anti-V5 antibody at 72-h post-transfection in the High Five cells, which is located in the cell cytoplasm. In vitro, overexpression of eIF4A rescued the apoptotic High Five cells induced by MbBV. Conversely, in vivo, loss of eIF4A proteins by dsRNA feeding increased apoptosis of hemocytes. Furthermore, RNAi and parasitism significantly increased apoptosis of hemocytes in S. litura. These findings suggested that MbBV inhibited the expression of eIF4A, which was required for apoptosis mediated by MbBV. This study will contribute to biological pest control and enhance our understanding of molecular mechanisms underlying polydnavirus-parasitoid-host interaction.

Identification of β-chain of Fo F1 -ATPase in apoptotic cell population induced by Microplitis bicoloratus bracovirus and its role in the development of Spodoptera litura

Two physiological changes of Spodoptera litura parasitized by Microplitis bicoloratus are hemocyte-apoptosis and retarded immature development. β-Chain of F_o F₁ -ATPase was found from a S. litura transcriptome. It belongs to a conserved P-loop NTPase superfamily, descending from a common ancestor of Lepidopteran clade. However, the characterization of β-chain of ATPase in apoptotic cells and its involvement in development remain unknown. Here, the ectopic expression and endogenous F_o F₁ -ATPase β-chain occurred on S. litura cell membrane: in vivo, at the late stage of apoptotic hemocyte, endogenous F_o F₁ -ATPase β-chain was stably expressed during M. bicoloratus larva development from 4 to 7 days post-parasitization; in vitro, at an early stage of pre-apoptotic Spli221 cells by infecting with M. bicoloratus bracovirus particles, the proteins were speedily recover expression. Furthermore, endogenous F_o F₁ -ATPase β-chain was localized on the apoptotic cell membrane. RNA interference (RNAi) of F_o F₁ -ATPase β-chain led to significantly decreased head capsule width. This suggested that F_o F₁ -ATPase β-chain positively regulated the development of S. litura. The RNAi effect on the head capsule width was enhanced with parasitism. Our research found that F_o F₁ -ATPase β-chain was expressed and localized on the cell membrane in the apoptotic cells, and involved in the development of S. litura.

Evolution of High-Temperature Superconductivity from a Low-T_{c} Phase Tuned by Carrier Concentration in FeSe Thin Flakes

We report the evolution of superconductivity in an FeSe thin flake with systematically regulated carrier concentrations by the liquid-gating technique. With electron doping tuned by the gate voltage, high-temperature superconductivity with an onset at 48 K can be achieved in an FeSe thin flake with T_{c} less than 10 K. This is the first time such high temperature superconductivity in FeSe is achieved without either an epitaxial interface or external pressure, and it definitely proves that the simple electron-doping process is able to induce high-temperature superconductivity with T_{c}^{onset} as high as 48 K in bulk FeSe. Intriguingly, our data also indicate that the superconductivity is suddenly changed from a low-T_{c} phase to a high-T_{c} phase with a Lifshitz transition at a certain carrier concentration. These results help to build a unified picture to understand the high-temperature superconductivity among all FeSe-derived superconductors and shed light on the further pursuit of a higher T_{c} in these materials.

Deciphering the spectrum of somatic mutations in the entire mitochondrial DNA genome

The mitochondrion is a crucial intracellular organelle responsible for regulating cellular energy metabolism, producing free radicals, initiating and executing the apoptotic pathways. Previous studies have shown that somatic mutations in mitochondrial DNA are associated with various tumors, which may be involved during carcinogenesis and tumor progression. To examine the mutation pattern in cancer, 625 reported somatic mutations in the mitochondrial DNA genome were analyzed. We found that, except for deletions and insertions, most somatic mutations were point mutations, accounting for 89.44% of somatic mutations. Transition was the predominant form of somatic mutation in the entire mitochondrial DNA genome, accounting for 87.12% of point mutations, most of which were homoplastic. Frequency statistics analysis of point mutations indicated that, except for 3 tRNA genes, the mutations were distributed on all resting genes and in the D-loop region, with the latter showing the highest frequency of somatic mutation (19.34%), followed by the tRNA leucine 2 gene and non-coding regions between base pairs 5892 and 5903, while 13 coding-region genes and 2 rRNA genes showed a relatively lower frequency of somatic point mutations. Nonsynonymous mutations and terminal amino acid changes were the primary point somatic mutations detected from 13 coding-region genes, which may cause mitochondrial dysfunction in cancer cells. We found that the somatic mutations may affect the mitochondrial DNA genome; the non-coding region should be examined to identify somatic mutations as potential diagnostic biomarkers for early detection of cancer.

Induction of apoptosis by capsaicin in hepatocellular cancer cell line SMMC-7721 is mediated through ROS generation and activation of JNK and p38 MAPK pathways

Capsaicin, one of the major pungent ingredients found in red peppers, has been shown to have anti-carcinogenic effect on various cancer cells through multiple mechanisms. In this study, we investigated the apoptotic effect of capsaicin on human hepatocellular cancer cell line SMMC-7721, as well as the possible mechanisms involved. Treatment of SMMC-7721 cells with capsaicin resulted in a dose-dependent inhibition of cell-viability and induction of apoptosis which was associated with the generation of ROS and persistent disruption of mitochondrial membrane potential. These effects were significantly blocked when cells were pretreated with a general antioxidant N-acetyl cysteine (NAC). We also found that capsaicin induced JNK and p38 MAPK phosphorylation. JNK and p38 MAPK inhibitor effectively blocked capsaicin-induced SMMC-7721 cell apoptosis. In addition, NAC completely blocked phosphorylation of JNK and p38 MAPK induced by capsaicin. Our results indicate that capsaicin induced in SMMC-7721 cell apoptosis through generation of intracellular ROS and activation of JNK and p38 MAPK pathways.

UVB-dependent generation of reactive oxygen species by catalase and IgG under UVB light: Inhibition by antioxidants and anti-inflammatory drugs

Catalase, which can decompose H2O2, has recently been found to generate unspecified reactive oxygen species (ROS) as a result of ultraviolet B (UVB) irradiation. Many proteins, hemes, and iron compounds were first tested to determine that this ROS generation was unique to catalase and immunoglobulin G (IgG). An increase in absorbance at 502 nm due to 2',7'-dichlorofluorescein, the oxidized product of 2',7'-dichlorodihydrofluorecein diacetate as a result of UVB (310 nm) irradiation, was measured in order to estimate this ROS generation. Catalase and IgG generated a pronounced amount of ROS when irradiated with UVB. Another heme protein, cytochrome c, and heat-inactivated catalase had no such effect. ROS generation by catalase was at least 5 times more potent than that reported for IgG with UVB and without antigens. This catalasemediated ROS generation was largely temperaturedependent in the range of 25 to 42°C. As IgG is considered an evolutionally important bactericidal component, the same was considered true for this enzyme. Next, inhibitory effects of various drugs, including antioxidants and anti-inflammatory drugs, on catalase-mediated and UVB-induced ROS generation were examined. Many of the drugs, including catalase inhibitors, had inhibitory effects with different potencies. Melanin was found to be the most effective inhibitor of this ROS generation (IC(30), 0.2 μg/mL), followed by Indigo Carmine and rutin. Also inhibiting this ROS generation were ascorbic acid, α-tocopherol, indomethacin, coenzyme Q10, β-carotene, uric acid, piroxicam, diclofenac, and glutathione, in that order of potency. Various ROS were apparently generated by catalase under UVB, creating a cycle or chain which was thought due to the biphasic effects of some drugs such as 3-aminotriazole or sodium azide. Excess ROS generation induces inflammation. Catalase might serve dual roles, removing H2O2 and generating various ROS depending on the H2O2 concentration and other factors.

Alleviation of osteoarthritis by calycosin-7-O-beta-D-glucopyranoside (CG) isolated from Astragali radix (AR) in rabbit osteoarthritis (OA) model

OBJECTIVE

This work was undertaken to assess the protective effect of an isoflavonoid, calycosin-7-O-beta-D-glucopyranoside (CG), isolated from Astragali radix (AR) on the pathogenesis of osteoarthritis (OA)-like lesion in a rabbit model.

METHODS

Nine rabbits underwent an anterior cruciate ligament and menisectomy transection (ACLMT) of the rear knee joints to induce OA-like lesion. They were randomly divided into three groups (n=6/group): a negative control group treated with 200 microl of 0.5% (v/v) dimethyl sulfoxide (DMSO), a positive control group treated with 200 microl of 100 microM piroxicam, and a test group treated with 100 microg/500 microl of CG, where the test agents were administered by injection once a week for 4 weeks starting from the third week. Rabbits were then sacrificed to observe the progression of OA-like lesion. The synovial fluid was analyzed for the amounts of total proteins, glycosaminoglycans (GAG) and prostaglandin E(2) (PGE(2)). In addition, histopathologic analyses were performed on the OA-like articular cartilage with or without therapeutic treatments.

RESULTS

The total synovial fluid volume (P<0.05) was most strikingly reduced by the treatment with CG. Moreover, the CG treatment also significantly alleviated the OA-induced accumulation of prostaglandin (PG) (P<0.001) and total proteins (P<0.001) in the synovial fluid. The histopathologic analyses revealed that the CG treatment reduced the severity of the OA-like structural damages in the cartilage. However, the level of PGE(2), a pathologic inflammatory molecule, was not diminished by CG or piroxicam.

CONCLUSION

These results indicate that the isoflavonoid CG isolated from AR significantly alleviated the pathologic changes in the OA-like rabbit knee joints. This suggests that CG from AR could be a promising treatment for the therapy of OA.

[Effects of Rholida on the free radical metabolism and serum creatine kinase after exercise at plateau]

Objective. To study the effect of Rholida on free radical metabolism and serum creatine kinase CK) after exercise at plateau. Method. After staying at high altitude (4100 m) for 20 d, 40 healthy young men were divided into 4 groups randomly (Rholida, Acetazolamide, Xi' s capsule and control, 10 men each group). And their SOD, MDA, GSH-Px CK, and CK-MB were determined respectively. Before, after taking drugs and after finishing the 5 min-stair-exercise. Result. Before taking drugs and after exercise, MAD GSH-Px, CK, CK-MB, increased as compared with quiet state (P<0.05, P<0.01), but SOD showed no significant chang (P>0.05). After taking drugs for 6 d, those who took Rholida, Acetazolamide and Xi's capsule, their MAD, GSH-Px CK, CK-MB increased after exercise as compared with quiet state (P<0.05). In Rholida group SOD increased and had significant change (P<0.05); but there was no significant change in Acetazolamide, Xi' s capsule group, SOD increased, MDA decreased (P<0.05), CK, CK-MB had no significant change (P>0.05), GSH-Px increased in Xi's group (P<0.05), but not in Acetazolamide group (P>0.05). SOD, GSH-Px increased, MDA, CK-MB decreased in Rholida group after taking drugs and the changes were significant (P<0.01). In Acetazolamide and Xi's capsule group, GSH-Px increased significantly, MDA, CK, CK-MB decreased significantly (P<0.05), but SOD didn't (P>0.05). Conclusion. Rholida, Acetazolamide, Xi's capsule could regulate the disorder of free radical metabolism at plateau and Rholida had advantage over the others.

[The changes of coagulation and fibrinolysis function on hypoxia adaptation mechanism]

AIM AND METHODS

To determine their Antithrombin-III (AT-III), Plasminogen (PLG), D-Dimer (DD), tissue-Plasminogen Activator (t-PA), Plasminogen Activator Inhibitor (PAI), Fibrinogen (Fg) and alpha2-Plasmin, inhibitor (alpha2-PI), when 40 subjects entered to high altitude, and compared with healthy flatlander.

RESULTS

At high altitude (3 700 m, 5 380 m) the AT-III abd t-PA were lower significantly than that of the flatlander (1 400m) (P < 0.05 or P < 0.01). The higher altitude subjects enter, the lower count will take (P < 0.01), and with the longer stay time, there was a higher count (P < 0.05 or P < 0.01). The 7th day at high altitude, PLG. DD. PAI. alpha2-PI and Fg were much higher than the flatlander's (P < 0.05 or P < 0.01), and with the higher elevation, there were higher datas, and with the longer stay time, there were lower datas (P < 0.05 or P < 0.01). Compare the a half of year at 3 700m with the flatlands, the results isn't discrepant (P > 0.05).

CONCLUSION

There is a coagulation-function disorder at high altitude, the results shows that coagulation and fibrinolysis are activated and fibrinolysis is inhibited yet, so the coagulation-fibrinolysis balance is destroyed. This effects lead to a hypercoagulation and hypo fibrinolysis state.

Orthotopic transplantation model of human gastrointestinal cancer and detection of micrometastases

AIM: To establish a relevant animal model of human gastrointestinal cancer, which can be used for repetitive investigations, so as to improve our understanding and management of carcinogenesis and cancer metastasis.

METHODS: Intact tissues of human colorectal and pancreatic cancers were transplanted in nude mice. The biological characteristics of the original and the corresponding transplanted tumors were investigated by HE staining, PAS staining and immunostaining. The metastases in the livers and lungs of nude mice were investigated by immunostaining with biotinylated mab KL-1 and by RT-PCR using CK20 specific primers.

RESULTS: There were totally 9 of 16 surgical specimens growing in nude mice subcutaneously and/or orthotopically (4 of 6 colorectal and 5 of 10 pancreatic cancer). Tumor cell content of the specimens and freezing of tissue specimens are important factors influencing the growth of transplanted tumor. In the group of fresh tumor tissues with greater than 50% tumor cell content, the success rate of the transplantation was 100% (3 cases of pancreatic cancer and 3 cases of colorectal cancer). The orthotopically transplanted tumors resemble the original tumor morphologically and biologically, including TAA expression such as CEA by immunohistochemistry, and CEA level in the serum of mice. Ki-67 labeling index and the expression of TAA especially K-ras, 17-1A and RA-96, are associated with the potential of tumor growth in nude mice. Micrometastases in the lungs and livers of tumor bearing mice can be detected by immunostaining with biotinylated mab KL-1 and CK20-specific RT-PCR.

CONCLUSION: An orthotopic transplantation model for human colon and pancreatic cancer in nude mice has been set up. We have also established sensitive detection methods with CK-immunohistochemistry and CK20-RT-PCR to study xenotransplanted human cancer and its metastatic cancer cells in the liver and lung of nude mice. This study may be helpful in understanding the mechanism of cancer metastasis and in developing new diagnostic methods and therapeutic strategies for metastases including micrometastases.

Preparation and physical characterization of alginate microparticles using air atomization method

Alginate microparticles were prepared using an air atomization method and varying formulation and processing conditions. Thereafter, the size and surface morphology of alginate microparticles were characterized. The trapping efficiencies of the ketoconazole, acetaminophen, vitamin C, and Bifidobacteria bifidum as model core materials were then determined. The air atomization process produced free-flowing and small-size microparticles after the freeze-drying process. The size distribution and surface morphology varied depending on the concentration of wall-forming materials and processing conditions. Generally, the geometric mean size increased as the concentration of alginate and poly-1-lysine and the delivery rate increased, but the air pressure decreased. Most of all, the ratio of delivery rate of alginate solution and air pressure could affect the size and surface morphology of alginate microparticles. However, the geometric mean size of alginate poly-1-lysine microparticles reproducibly ranged from about 80 to 130 microm. The microparticles were irregularly spherical or elliptical. The trapping efficiencies of ketoconazole, acetaminophen, vitamin C, and bifidobacteria were determined to be 71.5%, 60.1%, 1.6%, and 31%, respectively, when alginate concentration (1.5%), poly-1-lysine concentration (0.02%), air pressure (0.75 bar), delivery rate (8 ml/min), and spraying distance (45 cm) were applied. The current microencapsulation process using the air atomization method provides an alternative to entrapping small molecules and macromolecules without using harmful organic solvents. In addition, the small-size and free-flowing alginate microparticles containing active substances can be used as an intermediate in pharmaceutical applications.

Survival and stability of bifidobacteria loaded in alginate poly-l-lysine microparticles

Bifidobacteria-loaded alginate microparticles were prepared by spraying a mixture of alginate and bifidobacteria culture using an air atomization method. Survival and stability of bifidobacteria loaded in microparticles were then evaluated. Survival of bifidobacteria from alginate poly-l-lysine microparticles was significantly increased when MRS broth or yeast extract was added in simulated intestinal fluid (pH 6.8). The number of bifidobacteria gradually increased for 8 h (10(8) cfu/g) and then reached about 10(9)-10(10) cfu/g when incubated over 12 h in intestinal fluid containing 0.5% yeast extract and 0.05% L-cysteine. The survival of bifidobacteria was highly dependent on the pH of the exposing media. When the bifidobacteria was immobilized with alginate or even poly-l-lysine treatment, the survival of bifidobacteria was highly enhanced in the low pH conditions (ca. > 10(8) vs. < 10(3) cfu/g). The stability of free flowing bifidobacteria-loaded alginate poly-l-lysine microparticles was significantly improved during storage at 4 degrees C in a refrigerator when compared to bifidobacteria cultures. The bifidobacteria-loaded alginate poly-l-lysine microparticles could be applied to various dairy products.

Controlled release of dual drug-loaded hydroxypropyl methylcellulose matrix tablet using drug-containing polymeric coatings

A dual drug-loaded hydroxypropylmethylcellulose (HPMC) matrix tablet simultaneously containing drug in inner tablet core and outer coated layer was formulated using drug-containing aqueous-based polymeric Eudragit RS30D dispersions. Effects of coating levels, drug loadings in outer layers, amount and type of five plasticizers and talc concentration on the release characteristics were evaluated on the characteristics in simulated gastric fluid for 2 h followed by a study in intestinal fluids. Melatonin (MT) was selected as a model drug. The surface morphology of dual drug-loaded HPMC tablets using scanning electron microscope (SEM) was smooth, showing the distinct coated layer with about 75-microm coating thickness at the 15% coating level. Unlike the uncoated and conventionally coated HPMC tablet, the dual drug-loaded HPMC matrix tablet gave a biphasic linear release, showing a zero-order for 4 h (first) followed by another zero-order release when fitted using linear regression (r(2) = 0.99). As the coating levels (15, 25%) increased, the release rate was further decreased. The biphasic release profiles of dual drug-loaded HPMC matrix tablet was unchanged except when 25% coating level containing 0.5% drug concentration was applied. As the drug concentration in polymeric coating dispersion increased (0.25-1.0%), the amount of drug released increased. The time for the first linear release was also advanced. However, the biphasic release pattern was not changed. The biphasic release profiles of dual drug-loaded HPMC matrix tablet were highly modified, depending on the amount and type of five plasticizers. Talc (10-30%) in coating dispersion as an anti-sticking material did not affect the release profiles. The current dual drug-loaded HPMC matrix tablet, showing biphasic release profiles may provide an alternative to deliver drugs with circadian rhythmic behaviors in the body but needs to be further validated in future in human studies. The dual drug-loaded coating method is also interesting for the modified release of poorly water-soluble drugs because solubilizers and other additives can be added in drug-containing polymeric coating dispersions.

Formulation and release characteristics of hydroxypropyl methylcellulose matrix tablet containing melatonin

A hydroxypropyl methylcellulose (HPMC) matrix tablet containing melatonin (MT) was formulated as a function of HPMC viscosity, drug loading, type and amount of disintegrant, lubricant and glidant, and aqueous polymeric coating level and was compared with two commercial products. The release characteristics of the HPMC matrix tablet were investigated in the gastric fluid for 2 hr followed by study in intestinal fluid. The surface morphology of an uncoated HPMC matrix tablet using scanning electron microscopy (SEM) was crude, showing aggregated particles and rough crystals or pores, but it became smoother as the coating levels increased. As the HPMC polymer viscosity increased, the release rate had a tendency to decrease. As the drug loadings increased, the release rate slightly decreased. When Polyplasdone XL, Primojel, and Ac-Di-Sol, except Avicel, were incorporated in the HPMC matrix tablet, the release rate was markedly increased. There was no significant difference in release profiles when a mixture of lubricants and glidants (magnesium stearate, talc, and Cab-O-Sil), except for magnesium stearate alone, was incorporated into low and high viscosity grade HPMC matrix tablets. As the coating level increased, the release rate gradually decreased, giving an increased lag time. The sustained-release HPMC matrix tablet with optimizing formulations may provide an alternative for oral controlled delivery of MT and be helpful in the future treatment of circadian rhythmic disorders.

Biphasic release characteristics of dual drug-loaded alginate beads

The dual drug-loaded alginate beads simultaneously containing drug in inner and outer layers were prepared by dropping plain (single-layered) alginate beads into CaCl2 solution. The release characteristics were evaluated in simulated gastric fluid for 2 h followed by intestinal fluids thereafter for 12 h. The surface morphology and cross section of dual drug-loaded alginate beads was also investigated using scanning electron microscope (SEM). The poorly water-soluble ibuprofen was chosen as a model drug. The surface of single-layered and dual drug-loaded alginate beads showed very crude and roughness, showing aggregated particles, surface cracks and rough crystals. The thickness of dual drug-loaded alginate beads surrounded by outer layer was ranged from about 57 to 329 microns. The distinct chasm between inner and outer layers was also observed. In case of single-layered alginate beads, the drug was not released in gastric fluid but was largely released in intestinal fluid. However, the release rate decreased as the reinforcing Eudragit polymer contents increased. When the plasticizers were added into polymer, the release rate largely decreased. The release rate of dual drug-loaded alginate beads was stable in gastric fluid for 2 h but largely increased when switched in intestinal fluid. The drug linearly released for 4 h followed by another linear release thereafter, showing a distinct biphasic release characteristics. There was a difference in the release profiles between single-layered and dual drug-loaded alginate beads due to their structural shape. However, this biphasic release profiles were modified by varying formulation compositions of inner and outer layer of alginate beads. The release rate of dual drug-loaded alginate beads slightly decreased when the outer layer was reinforced with Eudragit RS100 polymers. In case of dual drug-loaded alginate beads with polymer-reinforced outer layer only, the initial amount of drug released was low but the initial release rate (slope) was higher due to more swellable inner cores when compared to polymer-reinforced inner cores. The current dual drug-loaded alginate beads may be used to deliver the drugs in a time dependent manner.

Intact tissue of gastrointestinal cancer specimen orthotopically transplanted into nude mice

BACKGROUND/AIMS

A relevant animal model of human gastrointestinal cancer in nude mice, which can be adapted for repetitive investigations, could improve our understanding of carcinogenesis and cancer metastasis. Furthermore, it may support the development of new and effective therapeutic concepts.

METHODOLOGY

We have established an orthotopic transplantation tumor model for human tumors in nude mice with intact tissues of colorectal, pancreatic, and gastric cancer. We investigated the biological characteristics of original and corresponding transplanted tumors, including routine pathological examination (HE staining), mucin production (PAS staining), and immunostaining. In addition, the lung and liver specimens were screened for micrometastases.

RESULTS

1) Overall, 10 out of 22 surgical specimens were growing in nude mice subcutaneously and/or orthotopically (4/6 colon, 5/10 pancreatic, and 1/6 gastric cancer). In the group of fresh tumor tissues with greater than 50% tumor cell content, the take rate was 100% (3/3 pancreatic, and 3/3 colon). 2) The orthotopically transplanted tumors resemble the original tumors morphologically and biologically, including local invasion, regional and distant metastases, and CEA production. 3) The detection of dissemination of cancer cells can be achieved by immunostaining.

CONCLUSIONS

An orthotopic xenotransplantation model for human gastrointestinal carcinomas in nude mice was established. The comparative analysis by immunohistochemistry suggests that this study will be helpful for developing new diagnostic methods to monitor micrometastatic disease.

Percutaneous absorption and model membrane variations of melatonin in aqueous-based propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles

Percutaneous absorption and model membrane variations of melatonin (MT) in aqueous-based propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles were investigated. The excised hairless mouse skin (HMS) and two synthetic ethylene vinyl acetate (EVA) and microporous polyethylene (MPE) were selected as a model membrane. The solubility of MT was determined by phase equilibrium study. The vertical Franz type cell was used for diffusion study. The concentration of MT was determined using reverse phase HPLC system. The MT solubility was the highest in a mixture of PG and 2-HP beta CD. The percutaneous absorption of MT through excised HMS increased as the solubility increased. However, the permeability coefficient decreased and then slightly increased in a mixture of PG and 2-HP beta CD. On the other hand, both flux and permeability coefficient through EVA membrane decreased as the solubility increased. No MT was detected over 12 h after starting diffusion through MPE membrane. The flux of MT was dependent on the type of membrane selected. Flux of MT was greatest in excised HMS followed by EVA and MPE membrane. Flux of MT through EVA membrane was 5-20 times lower when compared to excised HMS. Interestingly, volumes of donor phase when MPE membrane was used, significantly increased during the study period. The HMS might be applicable to expect plasma concentration of MT in human subjects based on flux and pharmacokinetic parameters as studied previously. The current studies may be applied to deliver MT transdermally using aqueous-based vehicles and to fabricate MT dosage forms.

[Photodynamic effect of chlorophyll derivative (CPD4) with pulsed copper-vapor laser on mouse transplanted tumor]

An experimental study on photodynamic effect of newly developed photosensitizer CPD4 with pulsed copper-vapor laser and pumped dye laser to mouse transplanted tumor (CT26) was carried out. The results showed that: (1) Ten days after treatment by CPD4 with 630nm laser, the mean tumor volume of control group (n = 9) was 1.0 +/- 0.68cm3, while that of treatment group (n = 18) was 0.45 +/- 0.5cm3 (P < 0.01), with an inhibitory rate of 55%. In the treatment group, 8 mice that were treated with a dose > or = 50mg/kg(iv) of CPD4, 280mW/cm2 of laser power density and 10 minutes of irradiation, were all cured with survival time over 6 months, while that of mice in the control group was 28.2 days (2) Under certain condition (light energy 120 J/cm2), with CPD4 as a sensitizer, the mean depths of tumor necrosis were 4.9 +/- 1.0mm (n = 5), 2.8 +/- 1.1mm(n = 11), 1.8 +/- 0.5mm(n = 9) for wavelength of 670nm, 630nm and 510nm, respectively (P < 0.01). When a conventional photosensitizer hematoporphyrin derivative was used, the depths of tumor necrosis were 0 (n = 6) 2.3 +/- 0.3 (n = 5) and 2.8 +/- 1.2 (n = 5)mm for 670, 630 and 510nm, respectively. Based on the above mentioned results, a rational treatment condition in clinical application of CPD4 with copper-vapor laser and pumped dye laser was suggested.