Design, synthesis, and biological evaluation of N-(pyridin-3-yl)pyrimidin-4-amine analogues as novel cyclin-dependent kinase 2 inhibitors for cancer therapy.

The discovery and development of CDK2 inhibitors has currently been validated as a hot topic in cancer therapy. Herein, a series of novel N-(pyridin-3-yl)pyrimidin-4-amine derivatives were designed and synthesized as potent CDK2 inhibitors. Among them, the most promising compound 7l presented a broad antiproliferative efficacy toward diverse cancer cells MV4-11, HT-29, MCF-7, and HeLa with IC50 values of 0.83, 2.12, 3.12, and 8.61 µM, respectively, which were comparable to that of Palbociclib and AZD5438. Interestingly, these compounds were less toxic on normal embryonic kidney cells HEK293 with high selectivity index. Further mechanistic studies indicated 7l caused cell cycle arrest and apoptosis on HeLa cells in a concentration-dependent manner. Moreover, 7l manifested potent and similar CDK2/cyclin A2 nhibitory activity to AZD5438 with an IC50 of 64.42 nM. These findings revealed that 7l could serve as ahighly promisingscaffoldfor CDK2 inhibitors as potential anticancer agents and functional probes.

SETD2 Loss and ATR Inhibition Synergize to Promote cGAS Signaling and Immunotherapy Response in Renal Cell Carcinoma.

PURPOSE: Immune checkpoint blockade (ICB) demonstrates durable clinical benefits in a minority of patients with renal cell carcinoma (RCC). We aimed to identify the molecular features that determine the response and develop approaches to enhance it. EXPERIMENTAL DESIGN: We investigated the effects of SET domain-containing protein 2 (SETD2) loss on the DNA damage response pathway, the cytosolic DNA-sensing pathway, the tumor immune microenvironment, and the response to ataxia telangiectasia and rad3-related (ATR) and checkpoint inhibition in RCC. RESULTS: ATR inhibition activated the cyclic GMP-AMP synthase (cGAS)-interferon regulatory factor 3 (IRF3)-dependent cytosolic DNA-sensing pathway, resulting in the concurrent expression of inflammatory cytokines and immune checkpoints. Among the common RCC genotypes, SETD2 loss is associated with preferential ATR activation and sensitizes cells to ATR inhibition. SETD2 knockdown promoted the cytosolic DNA-sensing pathway in response to ATR inhibition. Treatment with the ATR inhibitor VE822 concurrently upregulated immune cell infiltration and immune checkpoint expression in Setd2 knockdown Renca tumors, providing a rationale for ATR inhibition plus ICB combination therapy. Setd2-deficient Renca tumors demonstrated greater vulnerability to ICB monotherapy or combination therapy with VE822 than Setd2-proficient tumors. Moreover, SETD2 mutations were associated with a higher response rate and prolonged overall survival in patients with ICB-treated RCC but not in patients with non-ICB-treated RCC. CONCLUSIONS: SETD2 loss and ATR inhibition synergize to promote cGAS signaling and enhance immune cell infiltration, providing a mechanistic rationale for the combination of ATR and checkpoint inhibition in patients with RCC with SETD2 mutations.

Panax quinquefolius polysaccharides ameliorate ulcerative colitis in mice induced by dextran sulfate sodium.

This study aimed to investigate the ameliorative effect of the polysaccharides of Panax quinquefolius (WQP) on ulcerative colitis (UC) induced by dextran sulfate sodium (DSS) in mice and to explore its mechanism. Male C57BL/6J mice were randomly divided into the control group (C), model group (DSS), positive control mesalazine (100 mg/kg, Y) group, and low (50 mg/kg, L), medium (100 mg/kg, M) and high dose (200 mg/kg, H) of WQP groups. The UC model was induced by free drinking water with 2.5% DSS for 7 days. During the experiment, the general condition of the mice was observed, and the disease activity index (DAI) was scored. The conventional HE staining was used to observe pathological changes in mice's colon, and the ELISA method was used to detect the levels of interleukin-6 (IL-6), IL-4, IL-8, IL-10, IL-1ß and tumor necrosis factor-α (TNF-α) in mice's colon. The changes in gut microbiota in mice were detected by high-throughput sequencing; the concentration of short-chain fatty acids (SCFAs) was determined by gas chromatography; the expression of related proteins was detected by Western blot. Compared with the DSS group, the WQP group showed a significantly lower DAI score of mice and an alleviated colon tissue injury. In the middle- and high-dose polysaccharides groups, the levels of pro-inflammatory cytokines IL-6, IL-8, IL-1ß and TNF-α in the colonic tissue were significantly decreased (P<0.05), while the levels of IL-4 and IL-10 were significantly increased (P<0.05). The 16S rRNA gene sequencing results showed that different doses of WQP could regulate the composition and diversity of gut microbiota and improve its structure. Specifically, at the phylum level, group H showed an increased relative abundance of Bacteroidetes and a decreased relative abundance of Firmicutes compared with the DSS group, which was closer to the case in group C. At the family level, the relative abundance of Rikenellaceae in L, M and H groups increased significantly, close to that in group C. At the genus level, the relative abundance of Bacteroides, Shigella and Oscillospira in the H group increased significantly, while that of Lactobacillus and Prevotella decreased significantly. The high-dose WQP group could significantly increase the contents of acetic acid, propionic acid, butyric acid, and total SCFAs. Different doses of WQP also increased the expression levels of tight junction proteins ZO-1, Occludin and Claudin-1. To sum up, WQP can regulate the gut microbiota structure of UC mice, accelerate the recovery of gut microbiota, and increase the content of Faecal SCFAs and the expression level of tight junction proteins in UC mice. This study can provide new ideas for the treatment and prevention of UC and theoretical references for the application of WQP.

American ginseng with different processing methods ameliorate immunosuppression induced by cyclophosphamide in mice via the MAPK signaling pathways.

This study aimed to clarify the effects of two processed forms of American ginseng (Panax quinquefolius L.) on immunosuppression caused by cyclophosphamide (CTX) in mice. In the CTX-induced immunosuppressive model, mice were given either steamed American ginseng (American ginseng red, AGR) or raw American ginseng (American ginseng soft branch, AGS) by intragastric administration. Serum and spleen tissues were collected, and the pathological changes in mice spleens were observed by conventional HE staining. The expression levels of cytokines were detected by ELISA, and the apoptosis of splenic cells was determined by western blotting. The results showed that AGR and AGS could relieve CTX-induced immunosuppression through the enhanced immune organ index, improved cell-mediated immune response, increased serum levels of cytokines (TNF-α, IFN-γ, and IL-2) and immunoglobulins (IgG, IgA, and IgM), as well as macrophage activities including carbon clearance and phagocytic index. AGR and AGS downregulated the expression of BAX and elevated the expression of Bcl-2, p-P38, p-JNK, and p-ERK in the spleens of CTX-injected animals. Compared to AGS, AGR significantly improved the number of CD4+CD8-T lymphocytes, the spleen index, and serum levels of IgA, IgG, TNF-α, and IFN-γ. The expression of the ERK/MAPK pathway was markedly increased. These findings support the hypothesis that AGR and AGS are effective immunomodulatory agents capable of preventing immune system hypofunction. Future research may investigate the exact mechanism to rule out any unforeseen effects of AGR and AGS.

S100a8/a9 contributes to sepsis-induced cardiomyopathy by activating ERK1/2-Drp1-mediated mitochondrial fission and respiratory dysfunction.

Sepsis-induced cardiomyopathy (SIC) is the main complication and a leading cause of death in intensive care units. S100a8/a9 is a calcium-binding protein that participates in various inflammatory diseases; however, its role in sepsis-induced cardiomyopathy and the underlying mechanism remains to be explored. Here, septic cardiomyopathy was induced with cecal ligation and puncture (CLP) in S100a9-knockout (KO) mice lacking the heterodimer S100a8/a9 or wild-type (WT) mice administered with an S100a9-specific inhibitor Paquinimod (Paq), which prevents the binding of S100a9 toTLR4. Our results showed that S100a8/a9 expression in the heart peaked 24 h following the CLP operation, declined at 48 h and returned to baseline at 72 h. Loss of S100a9 by knockout in mice protected against CLP-induced mortality, cardiac dysfunction, myocyte apoptosis, recruitment of Mac-2+ macrophages, superoxide production, and the expression of pro-inflammatory cytokines genes compared with WT mice. Moreover, S100a9-KO significantly attenuated CLP-induced activation of the ERK1/2-Drp1 (S616) pathway, excessive mitochondrial fission, and mitochondrial respiration dysfunction. In contrast, activation of ERK1/2 with its agonist tBHQ reversed the inhibitory effects of S100a9-knockout on CLP-induced cardiomyopathy and mitochondrial dysfunction. Finally, administration of Paq to WT mice markedly prevented the CLP-induced cardiomyopathy mitochondrial fission and dysfunction compared with vehicle control. In summary, our data reveal, for the first time, that S100a8/a9 plays a critical role in mediating SIC, presumably by activating TLR4-ERK1/2-Drp1-dependent mitochondrial fission and dysfunction and highlight that blockage of S100a8/a9 may be a promising therapeutic strategy to prevent SIC in patients with sepsis.

Potential Gains in Health-Adjusted Life Expectancy by Reducing Burden of Noncommunicable Diseases in 188 Countries: A Population-Based Study.

OBJECTIVES: This article quantifies the potential gains in health-adjusted life expectancy for people aged 30 to 70 years (HALE[30-70]) by examining the reductions in disability in addition to premature mortality from noncommunicable diseases (NCDs). METHODS: We extracted data from the Global Burden of Disease Study 2019 for 4 major NCDs (cancers, cardiovascular diseases, chronic respiratory diseases, and diabetes mellitus) in 188 countries from 2010 to 2019. Estimates of the potential gains in HALE[30-70] were based on a counterfactual analysis involving 3 alternative future scenarios: (1) achieve Sustainable Development Goals target 3.4 but do not make any progress on disability reduction, (2) achieve Sustainable Development Goals target 3.4 and eliminate NCD-related disability, and (3) eliminate all NCD-related mortality and disability. RESULTS: In all scenarios, the high-income group has the greatest potential gains in HALE[30-70], above the global average. For all specific causes, potential gains in HALE[30-70] decrease as income levels fall. Across these 3 scenarios, the potential gains in HALE[30-70] globally of reducing premature mortality for 4 major NCDs are 3.13 years, 4.53 years, and 7.32 years, respectively. In scenario A, all income groups have the greatest potential gains in HALE[30-70] from diabetes and chronic respiratory diseases. In scenarios B and C, the high-income group has the greatest potential gains in HALE[30-70] from cancer intervention, and the other income groups have the greatest potential gains in HALE[30-70] from cardiovascular diseases intervention. CONCLUSION: Reducing premature death and disability from 4 major NCDs at once and attaching equal importance to each lead to a sizable improvement in HALE[30-70].

Effect of Aqueous Enzymatic Extraction of Deer Oil on Its Components and Its Protective Effect on Gastric Mucosa Injury.

In this study, deer suet fat was used as a raw material to study the effects of aqueous enzymatic extraction of deer oil on its components, followed by studies into the potential protective activity, and related molecular mechanisms of deer oil on ethanol-induced acute gastric mucosal injury in rats. The results show that aqueous enzymatic extraction of deer oil not only has a high extraction yield and has a small effect on the content of active ingredients. Deer oil can reduce total stomach injury. Without affecting the blood lipid level, it can reduce the oxidative stress, which is manifested by reducing the content of myeloperoxidase (MPO) and enhancing the activity level of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). It also enhances the expression of defense factors prostaglandin (E2), epidermal growth factor (EGF), and somatostatin (SS), it inhibits apoptosis evidenced by the enhanced of Bcl-2 and decreased expression of cleavage of caspase-3 and Bax. At the same time, it reduces inflammation, which is manifested by reducing the expression of IL-1ß, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) gastric tissue pro-inflammatory cytokines, and enhancing the expression of anti-inflammatory factors IL-4 and IL-10, and inhibiting the mitogen-activated protein kinase/nuclear factor kappa B (MAPK/NF-κB) signaling pathway in gastric tissue.

[Simultaneous determination of 13 hormones in Testis et Penis Cervi using QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry].

A reliable QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) analysis method was developed for the simultaneous determination of 13 steroid hormones(nrolone, androstenedione, methyltestosterone, testosterone, norethindrone, medroxyprogesterone, progesterone, diethylstilbestrol, hexan-stilbestrol, estradiol, estrotriol, cortisone, hydrocortisone) in Testis et Penis Cervi. The samples were extracted with methanol and purified by QuEChERS. Subsequently, the samples were separated by ACQUITY BEH C_(18) column and detected in the multiple reaction monitoring(MRM) mode under electrospray ionization in the positive and negative ion modes, respectively. Significant differences in the content of thirteen steroid hormones in Testis et Penis Cervi between the sika deer at different periods and the red deer were observed. The content of testosterone(10.88 µg·kg~(-1)) and hydrocortisone(12.82 µg·kg~(-1)) in Testis et Penis Cervi derived from rutting sika deer was significantly higher than the content of testosterone(1.05 µg·kg~(-1)) and hydrocortisone(0.73 µg·kg~(-1)) from antler growth stage. The content of progesterone in Testis et Penis Cervi derived from red deer was 6.07 µg·kg~(-1), significantly higher than that from sika deer. The content of progesterone in the testicle of red deer reached 27.46 µg·kg~(-1), 4.5 times greater than that in the penis of red deer. The sensitivity, accuracy, and precision of the method can meet the detection requirements, and the developed method is suitable for the measurement of hormones in animal-derived food.

[Application of image guided technique in rhino-orbital related endoscopic surgery].

Objective:To review retrospectively six cases of rhino-orbital related endoscopic surgeries aided by Fusion electromagnetic system,to explore the indications and clinical value of image guided technique in endonasal endoscopic surgery.Method:Retrospective research methods were used.In this study,six cases of nasal endoscopic sinus surgery using Fusion electromagnetic system were analyzed,including 1 nasal penetrating foreign body,2 optic nerve decompressions,1 orbital apex hemangioma,1 sieve frontal sinus cyst,1 intraorbital mass biopsy.The preparation time of navigation system,the accuracy of intraoperative positioning and surgical coherence,intraoperative and postoperative complications of surgery were recorded.Result:The average preparation time was(8.13 ± 1.858)min.In the navigation,the sinus ostium,orbital cardboard,skull base,optic nerve,internal carotid artery and other important structures can be accurately located in all patients,while registrations had been accurate within 1 mm.Six patients were successfully operated by image guided technique.There was no intracranial or intraorbital complications due to intraoperation error.Conclusion:Image guided technique allows for a truely microinvasive and accurate rhino-orbital related endoscopic surgeries.It requires less preoperative preparation time,has high surgical navigation accuracy,improves the surgical coherence and safety,and reduces the surgical complicationgs.However,as an auxiliary tool,it can not replace the surgeon's anatomical knowledge,surgical training and clinical experience.

Paenibacillus shunpengii sp. nov., isolated from farmland soil.

A bacterial strain designated YYJ7-1T was isolated from farmland soil in China and characterized using a polyphasic taxonomic approach. Cells of strain YYJ7-1T were Gram-staining-positive, aerobic or facultatively anaerobic, rod-shaped, motile and endospore-forming. Growth occurred at 18-42 °C (optimum at 35 °C), at pH 6.0-8.0 (optimum at pH 7.5) and with 0.0-4.0 % NaCl (optimum with 0.5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain belonged to the genus Paenibacillus and showed high levels of sequence similarity with respect to Paenibacillus provencensis 4401170T (98.6 %) and Paenibacillus urinalis 5402403T (98.4 %), while lower 16S rRNA gene sequence similarities were observed with all other type strains (97.0 %). However, strain YYJ7-1T showed low DNA-DNA relatedness with P. provencensis 4401170T 48.7±4.5 % (43.6±7.1 % in a reciprocal experiment), and P. urinalis 5402403T 38.9±5.7 % (35.6±6.8 %). The major cellular fatty acids (>10.0 %) of strain YYJ7-1T were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The polar lipid profile consisted of phospholipids, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major isoprenoid quinone was MK-7. The DNA G+C content was 39.4 mol%. Based on these results, it is concluded that strain YYJ7-1T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus shunpengii sp. nov. is proposed, with YYJ7-1T (=ACCC 19965T=KCTC 33849T) as the type strain.

VASP activation via the Gα13/RhoA/PKA pathway mediates cucurbitacin-B-induced actin aggregation and cofilin-actin rod formation.

Cucurbitacin B (CuB), a potent antineoplastic agent of cucurbitacin triterpenoids, induces rapid disruption of actin cytoskeleton and aberrant cell cycle inhibiting carcinogenesis. However, the underlying molecular mechanism of such anticancer effects remains incompletely understood. In this study, we showed that CuB treatment rapidly induced vasodilator-stimulated phosphoprotein (VASP) phosphorylation (i.e. activation) at the Ser157 residue and generated VASP clumps which were co-localized with amorphous actin aggregates prior to the formation of highly-ordered cofilin-actin rods in melanoma cells. Knockdown of VASP or inhibition of VASP activation using PKA-specific inhibitor H89 suppressed CuB-induced VASP activation, actin aggregation and cofilin-actin rod formation. The VASP activation was mediated by cAMP-independent PKA activation as CuB decreased the levels of cAMP while MDL12330A, an inhibitor of adenylyl cyclase, had weak effect on VASP activation. Knockdown of either Gα13 or RhoA not only suppressed VASP activation, but also ameliorated CuB-induced actin aggregation and abrogated cofilin-actin rod formation. Collectively, our studies highlighted that the CuB-induced actin aggregation and cofilin-actin rod formation was mediated via the Gα13/RhoA/PKA/VASP pathway.

Formation of cofilin-actin rods following cucurbitacin-B-induced actin aggregation depends on Slingshot homolog 1-mediated cofilin hyperactivation.

Accumulating evidence indicates that cucurbitacin B (CuB), as well as other cucurbitacins, damages the actin cytoskeleton in a variety of cell types. However, the underlying mechanism of such an effect is not well understood. In this study, we showed that CuB rapidly induced actin aggregation followed by actin rod formation in melanoma cells. Cofilin, a critical regulator of actin dynamics, was dramatically dephosphorylated (i.e., activated) upon CuB treatment. Notably, the activated cofilin subsequently formed rod-like aggregates, which were highly colocalized with actin rods, indicating the formation of cofilin-actin rods. Cofilin knockdown significantly suppressed rod formation but did not prevent actin aggregation. Furthermore, knockdown of the cofilin phosphatase Slingshot homolog 1 (SSH1), but not chronophin (CIN), alleviated CuB-induced cofilin hyperactivation and cofilin-actin rod formation. The activity of Rho kinase and LIM kinase, two upstream regulators of cofilin activation, was downregulated after cofilin hyperactivation. Pretreatment with a thiol-containing reactive oxygen species (ROS) scavenger N-acetyl cysteine, but not other ROS inhibitors without thiol groups, suppressed CuB-induced actin aggregation, cofilin hyperactivation and cofilin-actin rod formation, suggesting that thiol oxidation might be involved in these processes. Taken together, our results demonstrated that CuB-induced formation of cofilin-actin rods was mediated by SSH1-dependent but CIN-independent cofilin hyperactivation.

Autophagy is differentially induced in prostate cancer LNCaP, DU145 and PC-3 cells via distinct splicing profiles of ATG5.

Autophagic responses to chemotherapeutic agents may vary greatly among different prostate cancer cells and have not been well characterized. In this study, we showed that valproic acid (VPA) induced conversion of LC3-I to LC3-II and formation of LC3 puncta, the typical markers of autophagy, in LNCaP and PC-3 cells. However, these markers were undetectable in DU145 cells upon autophagic stimulation, indicating a defect of autophagy in this cell line. Among several critical autophagy-related proteins, ATG5 and ATG12-ATG5 conjugates, which are essential for autophagy induction, were absent in DU145 cells. No canonical transcripts for full-length ATG5 but only two alternatively spliced ATG5 transcripts were identified in DU145 cells. These alternative transcripts lack one or two exons, leading to premature termination of ATG5 translation. Transfection of the wild-type ATG5 gene into DU145 cells rescued the production of ATG5 and ATG12-ATG5 conjugates, resulting in formation of LC3-II conjugates and LC3 puncta. Moreover, the levels of the SQSTM1 protein, which should be degradable as an autophagy adaptor, were much higher in DU145 than in LNCaP and PC-3 cells, but were significantly decreased after ATG5 restoration in DU145 cells. However, expression of wild-type ATG5 in DU145 or knockdown of ATG5 in LNCaP and PC-3 cells did not change the inhibitory effects of VPA on these cells. Collectively, these results indicated that VPA-induced autophagy in prostate cancer cells depended on ATG5 and more importantly, that the autophagy pathway was genetically impaired in DU145 cells, suggesting caution in interpreting autophagic responses in this cell line.

Cucurbitacin B induces cell cycle arrest, apoptosis and autophagy associated with G actin reduction and persistent activation of cofilin in Jurkat cells.

AIM: The present study aimed to explore the antitumor effect and action mechanism of cucurbitacin B (CuB) on human T-cell leukemia Jurkat cells. METHODS: Cell proliferation was measured by the MTS assay. Cell cycle distribution, mitochondrial membrane potential and annexin V staining were analyzed using flow cytometry. Western blotting was used to determine the levels of apoptosis- and autophagy-related proteins. RESULTS: CuB inhibited the proliferation of Jurkat cells in a dose-dependent manner and induced G 2 /M phase arrest as well as formation of tetraploid cells. Accompanied with these effects, the actin dynamics was disrupted, and cofilin, a key regulator of actin dynamics, was persistently activated (dephosphorylated). Although CuB induced around 10% cells undergoing apoptosis, most of the cells were alive after CuB treatment for 24 h. Induction of autophagy was also evident by accumulation of LC3-II. CuB-induced autophagy seemed to be a prosurvival response, since suppression of CuB-induced autophagy significantly increased the activation of caspase-3. CONCLUSION: Our results demonstrated that CuB exhibited antitumor activity in Jurkat cells through induction of cell cycle arrest and apoptosis which was at least partly due to the disruption of actin dynamics.

Valproic acid synergistically enhances the cytotoxicity of gossypol in DU145 prostate cancer cells: an iTRTAQ-based quantitative proteomic analysis.

Gossypol (GOS), a BH3 mimetic, has been investigated as a sensitizing co-therapy to radiation and chemotherapy in treatment of metastatic prostate cancer. In this study, we found that valproic acid (VPA), a histone deacetylase inhibitor (HDACI), counteracted the suppressive effect of GOS on histone H3 acetylation and enhanced the cytotoxicity of GOS to DU145 prostate cancer cells. Significant synergistic effects were observed in combined GOS and VPA treatment, culminating in more DNA damage and cell death. The iTRAQ-based quantitative proteomic analysis revealed differential proteomic profiles in cells treated with VPA, GOS or their combination. In GOS-treated cells, oxidative phosphorylation-related proteins were depressed and endoplasmic reticulum stress markers were upregulated. In the presence of VPA, the GOS-induced mitochondrial stress was further enhanced since glycolysis- and hypoxia-associated proteins were upregulated, suggesting a disruption of energy metabolism in these cells. Furthermore, the DNA damage repair ability of cells co-treated with GOS and VPA was also decreased, as evidenced by the downregulation of DNA damage repair proteins and the enhancement of DNA fragmentation and cell death. These findings suggest that GOS in combination with an HDACI has the potential to increase its clinical efficacy in the treatment of prostate cancer.

Valproic acid exhibits biphasic effects on apoptotic cell death of activated lymphocytes through differential modulation of multiple signaling pathways.

Valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, possesses potent anti-tumor activity against a variety of malignant cells. However, its action on lymphocytes and the underlying mechanism are not completely understood. In this study, we aimed to analyze the effects of VPA on the proliferation, activation, and apoptosis of murine lymphocytes activated with concanavalin A (ConA). Our results showed that VPA inhibited the proliferation of ConA-activated lymphocytes in a dose-dependent manner. Low-dose VPA (≤ 1.1 mM) enhanced CD69 expression on the activated lymphocytes, whereas at high doses (≥ 3.3 mM) it decreased CD69 expression. Furthermore, VPA reduced activation-induced apoptotic cell death at low doses, but at high doses it promoted apoptotic cell death of activated lymphocytes dramatically. It was found that the Bax/Bcl-2 ratio and phosphorylation of histone H2A.X was decreased at low doses of VPA but was increased at high doses. The phosphorylation of STAT3 was also differentially regulated by different doses of VPA. VPA, at 5 mM induced the phosphorylation of p38 but not JNK and extracellular signal-regulated kinase (ERK)1/2. In addition, VPA induced a dose-dependent increase in the acetylation of histone H3. These results demonstrate that VPA exhibits dose-dependent biphasic effect on apoptosis of activated lymphocytes probably through differential modulation of several apoptosis-related signaling pathways.

Numerical study on three-region thawing problem during cryosurgical re-warming.

Knowledge of the temperature transients of biological bodies during cryosurgical re-warming is critical for the survival of healthy tissues. To better understand the mechanisms thus involved, a one-dimensional numerical algorithm based on finite difference method was applied to simultaneously solve the thawing processes occurring in three regions with one thawing, another blood-perfused and the third frozen one sandwiched between them. Two typical surface heatings with heating plate or convective warm water and a spatial heating using microwave were particularly adopted to investigate the advancement of the two phase-change interfaces and the transient temperature field over the tissue. Differences among these results were compared and their implementation for the cryosurgical re-warming were discussed. Parametric studies were performed to explore influences of the blood perfusion, the microwave heating power, the surface heat convection coefficient, and the surface heating temperature to the thermal history of the biological bodies. Taking account of several typical blood re-flow patterns most probably occurred in the originally frozen and then thawed tissues after the two phase change interfaces meet together, four heat transfer equations were proposed to characterize the re-warming behavior of the biological body. Effect of the non-ideal solution property of the living tissues to the transient temperature field during cryo-surgical re-warming was also tested through introducing a simple however intuitive way.