[Study on the prognostic influencing factors of esophageal squamous cell carcinoma and the predictive value of inflammatory reaction indexes on its postoperative recurrence].

Objective: To explore the influence factors of poor prognosis of esophageal squamous cell carcinoma (ESCC) and the predictive value of inflammatory reaction indexes including neutrophils and lymphocytes ratio (NLR), platelet and lymphocyte ratio (PLR), monocyte and lymphocyte ratio (MLR) provision and differentiation degree, infiltration depth, lymph node metastasis number on the postoperative recurrence of ESCC. Methods: A total of 130 patients with ESCC who underwent radical resection from February 2017 to February 2019 in Nanyang Central Hospital were selected and divided into good prognosis group (66 cases) and poor prognosis group (64 cases) according to the prognostic effect. The clinical data and follow-up data were collected. Multivariate logistic regression analysis was used to determine the independent influencing factors of poor prognosis. Spearman correlation analysis was used to determine the correlation between preoperative NLR, PLR and MLR with the degree of differentiation, depth of invasion and number of lymph node metastases. Receiver operating characteristic (ROC) curve analysis was used to evaluate the efficacy of NLR, PLR and MLR in predicting poor prognosis of ESCC. Results: Univariate analysis showed that the degree of differentiation, the degree of invasion and the number of lymph node metastasis were related to the prognoses of patients with ESCC (P<0.05). Multivariate logistic regression analysis showed that the degree of differentiation, depth of invasion and number of lymph node metastases were independent influencing factors for poor prognosis of patients with ESCC, moderate differentiation (OR=2.603, 95% CI: 1.009-6.715) or low differentiation (OR=9.909, 95% CI: 3.097-31.706), infiltrating into fibrous membrane (OR=14.331, 95% CI: 1.333-154.104) or surrounding tissue (OR=23.368, 95% CI: 1.466-372.578), the number of lymph node metastases ≥ 3 (OR=9.225, 95% CI: 1.693-50.263) indicated poor prognosis. Spearman correlation analysis showed that NLR was negatively correlated with the degree of differentiation and the number of lymph node metastases (r=-0.281, P=0.001; r=-0.257, P=0.003), PLR was negatively correlated with the degree of differentiation, depth of invasion and number of lymph node metastasis (r=-0.250, P=0.004; r=0.197, P=0.025; r=-0.194, P=0.027), MLR was positively correlated with the degree of differentiation and the number of lymph node metastasis (r=0.248, P=0.004; r=0.196, P=0.025). ROC curve analysis showed that the areas under the curve of NLR, PLR and MLR in predicting poor prognosis of ESCC were 0.971, 0.925 and 0.834, respectively. The best cut-off value of NLR was 2.87. The sensitivity and specificity of NLR in predicting poor prognosis of ESCC were 90.6% and 87.9%, respectively. The optimal cut-off value of PLR was 141.75. The sensitivity and specificity for predicting poor prognosis of ESCC were 92.2% and 87.9%, respectively. The best cut-off value of MLR was 0.40. The sensitivity and specificity of MLR in predicting poor prognosis of esophageal squamous cell carcinoma were 54.7% and 100.0%, respectively. Conclusions: The degree of differentiation, the degree of invasion and the number of lymph node metastases are closely related to the poor prognosis of patients with esophageal squamous cell carcinoma. NLR, PLR and MLR can provide important information for predicting the poor prognosis of esophageal squamous cell carcinoma.

NLRP6 suppresses the inflammatory response of human periodontal ligament cells by inhibiting NF-κB and ERK signal pathways.

AIM: To explore the function and mechanisms of NLRP6 (NOD-, LRR- and pyrin domain-containing 6) in the inflammatory response of human periodontal ligament cells (HPDLCs). METHODOLOGY: Tissues associated with apical periodontitis were obtained from three patients who underwent endodontic microsurgery. The expression of NLRP6 in 3 human apical periodontitis tissues and HPDLCs was examined by immunohistochemistry and immunofluorescence, respectively. The expressions of NLRP6, Phospho(p)- p65, p65, IκB-α, p- IκB-α, ERK, p- ERK, NLRP3, Pro interleukin (IL)-1ß, Pro caspase-1 and apoptosis-associated speck-like protein containing a CARD (ASC) were examined by western blot. The gene expression and secretion of proinflammatory cytokines were detected using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Data were analysed statistically with independent sample t-tests. RESULTS: NLRP6 was expressed in inflammatory periapical tissues and HPDLCs. Lipopolysaccharide (LPS) from Escherichia coli induced NLRP6 in HPDLCs (P < 0.05). After silencing NLRP6, E. coli LPS-induced activation of NF-κB and ERK signalling was enhanced, which was also accompanied by elevated levels of IL-6 and tumour necrosis factor-α (TNF-α) (P < 0.05). Moreover, knockdown of NLRP6 led to up-regulation of NLRP3, Pro IL-1ß and Pro caspase-1 (P < 0.05), whereas down-regulation of ASC (P < 0.05), which may contribute to unchanged levels of IL-1ß in HPDLCs inflammation. CONCLUSION: NLRP6 was functionally expressed in inflamed periapical tissues and HPDLCs. NLRP6 negatively regulated the production of IL-6 and TNF-α in HPDLCs inflammation by inhibiting NF-κB and ERK signal pathways.

[Spectrometric analyses of larotaxel and larotaxel liposomes quantification by high performance liquid chromatography].

OBJECTIVE: Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes. METHODS: The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes. RESULTS: The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 µm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%. CONCLUSION: The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.

NLRP3 inflammasome may regulate inflammatory response of human periodontal ligament fibroblasts in an apoptosis-associated speck-like protein containing a CARD (ASC)-dependent manner.

AIM: To explore the role of NLRP3 (NACHT [nucleotide-binding oligomerization], LRR [leucine-rich repeat] and PYD [pyrin domain] domains-containing protein 3) inflammasome in the inflammatory response of human periodontal ligament fibroblasts (HPDLFs). METHODOLOGY: The expression of NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) in inflammatory periapical tissues and HPDLFs was examined by immunohistochemical and immunofluorescent staining. HPDLFs were stimulated with muramyl dipeptide (MDP) and lipopolysaccharide (LPS) from E. coli with or without the silencing of ASC. The expression of NLRP3, ASC and caspase-1 was examined using quantitative real-time polymerase chain reaction. The secretion of proinflammatory cytokines, including interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) was measured in the cell supernatant with an enzyme-linked immunosorbent assay. Data were statistically analysed using independent sample t-tests. RESULTS: Immunohistochemistry and immunocytochemistry staining revealed that NLRP3 and ASC were expressed in HPDLFs and inflammatory periapical tissues. MDP and LPS promoted the expression of NLRP3, ASC and caspase-1 in HPDLFs (P < 0.05). The secretion of proinflammatory cytokines was also increased with MDP and LPS stimulation (P < 0.05). After silencing ASC, the secretion of IL-1ß induced by MDP and LPS was significantly attenuated (P < 0.05). CONCLUSION: In HPDLFs, MDP and LPS activated NLRP3 inflammasome and induced IL-1ß secretion. ASC plays an important role in this inflammatory response.

Construction of KHV-CJ ORF25 DNA vaccine and immune challenge test.

KHV ORF25 fragments were cloned from Koi Herpes Virus-CJ (KHV-CJ) strains isolated in our laboratory. The amplified products were inserted into the eukaryotic expression vector pIRES-neo, forming recombinant plasmid pIRES-ORF25. The recombinant plasmid pIRES-ORF25 at 1 µg per koi, 10 µg per koi and 50 µg per koi was intramuscularly injected into healthy kois, respectively. The results showed that the recombinant pIRES-ORF25 could induce the production of specific antibodies in koi determined by indirect ELISA. The differences of immune effect between three doses were not significant (P > 0.05), but all of them could induce the production of neutralizing antibodies. The immune challenge test showed that the mortality of koi injected with PBS, blank pIRES-neo vector and nothing was 90%, 92.5% and 85% at 25 days. While the mortalities of koi injected with eukaryotic expression plasmid pIRES-ORF25 were 20%, 17.5% and 12.5%. Differences in comparison with the control group were highly significant (P < 0.01). Histopathological staining revealed that the tissues of the immunized koi did not change apparently. In conclusion, the DNA vaccine pIRES-ORF25 construct could well protect koi against KHV and had the potential to be applied in practice.

[Investigation and analysis of oral health resources allocation status in Yunnan Province].

Objective: To investigate and analyze the allocation status of oral health resources in Yunnan Province at the end of the 13th Five-Year Plan, providing a scientific basis for the rational resource allocation and formulation regional oral health plan for government health administrative departments. Methods: With the method of general survey, a cross-sectional study was conducted to investigate the allocation of material and human resources of all kinds of stomatological medical institutions registered in the health administrative departments in Yunnan before January 1, 2020. The general situation of oral health resources was analyzed by descriptive statistical analysis. Results: There were 2 712 stomatological medical institutions in Yunnan, 634 public and 2 078 non-public included. The largest number was in Kunming (1 167) and the least in Diqing (19). There were 9 018 dental chairs in total, among which 2 584 in public and 6 434 in non-public. Kunming had the largest number of chairs (3 612) and Nujiang had the least (57). There were 702 oral and maxillofacial surgical beds, all of which were distributed in public. There were 15 148 stomatological personnel, including 3 667 in public and 11 481 in non-public. The average ratio of stomatologist to population was 1∶6 615. Dehong (1∶6 620) was close to this average level, while Kunming (1∶2 283) and Yuxi (1∶4 936) were lower than the average and the other 13 states (cities) were higher. The population ratio of licensed stomatologist was only 1∶9 110. The average ratio of stomatologist to nurses was 1∶0.94. Honghe (1∶1.05), Kunming (1∶1.00), Yuxi (1∶1.18) and Qujing (1∶0.94) was better than or reached the average level, while the other 13 states (cities) were lower than this average. And this ratio in public comprehensive medical institutions was only 1∶0.38. Conclusions: The distribution of oral health resources in Yunnan was unbalanced between public and non-public institutions and among states (cities), mainly distributed in economically developed states (cities) and non-public institutions. For the oral health in Yunnan Province, the workforce was insufficient and the structure was unreasonable, and the proportion of nurses was seriously insufficient in public comprehensive medical institutions.

Phytases: crystal structures, protein engineering and potential biotechnological applications.

Phytases are a group of enzymes capable of releasing phosphates from phytates, one of the major forms of phosphorus (P) in animal feeds of plant origin. These enzymes have been widely used in animal feed to improve phosphorus nutrition and to reduce phosphorus pollution in animal waste. This review covers the basic nomenclature and crystal structures of phytases and emphasizes both the protein engineering strategies used for the development of new, effective phytases with improved properties and the potential biotechnological applications of phytases.

LINC00662 promotes cell proliferation, migration and invasion of melanoma by sponging miR-890 to upregulate ELK3.

OBJECTIVE: Melanoma is one of the most malignant types of skin tumors and accounts for the majority of skin cancer-related deaths. LINC00662 is a tumor promoter in multiple types of cancer, but the role of LINC00662 in melanoma has not been fully elucidated. MATERIALS AND METHODS: The expression levels of LINC00662, miR-890, and ELK3 were detected by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR). MTT assay was performed to measure the cell proliferation ability in A375 and SK-MEL-1 cells. Cell migration and invasion abilities were measured by wound healing assay and transwell assay, respectively. Besides, Luciferase reporter assay was employed to examine the interaction between miR-890 and LINC00662 or ELK3. RESULTS: In the present study, it was demonstrated that melanoma patients with high expression levels of LINC00662 had a shorter survival time than those with low expression levels of LINC00662. LINC00662 exhibited higher expression levels in melanoma tissues and cell lines. Additionally, suppression of LINC00662 impaired cell proliferation, migration, and invasion. Furthermore, animal experiments demonstrated that LINC00662 facilitated tumor growth in vivo. LINC00662 was confirmed to bind with miR-890, and ELK3 was identified as a downstream target gene of miR-890. Furthermore, miR-890 was found to negatively regulate ELK3 expression. Through rescue assays, overexpression of ELK3 reversed the inhibitive effects of LINC00662 knockdown or miR-890 mimics on the cell proliferative, migratory, and invasive abilities. CONCLUSIONS: Our results demonstrated that LINC00662 facilitated the occurrence and development of melanoma by sponging miR-890 to upregulate ELK3. This discovery implied that LINC00662 may be a promising prognostic and therapeutic biomarker for patients with melanoma.

Clinical efficacy of ticagrelor combined with aspirin in patients with coronary heart disease angina pectoris and its effects on NT-ProBNP and CK-MB levels.

OBJECTIVE: This study aims to explore the clinical efficacy of ticagrelor combined with aspirin in patients with coronary heart disease angina pectoris and the effects on N terminal pro B type natriuretic peptide (NT-ProBNP) and creatine kinase-MB (CK-MB) levels. PATIENTS AND METHODS: A total of 150 patients with coronary heart disease angina pectoris were prospectively analyzed in this study. These patients were admitted to Huaiyin Hospital of Huai'an City from February 2017 to February 2019. The patients were divided into control group and research group according to different treatment methods. The following indicators before and after treatment were observed: therapeutic efficacy, prevalence of adverse reactions, duration and frequency of angina attack, NT-ProBNP and CK-MB levels. Receiver operating characteristic (ROC) curve was used to analyze the predictive value of NT-ProBNP and CK-MB for the curative effect of coronary heart disease angina pectoris. RESULTS: The total effective rate in the research group was higher than that in the control group (p<0.05). The prevalence of adverse reactions in the research group was lower than that in the control group (p<0.05). The duration and frequency of seizures of the two groups after treatment were lower than those before treatment. The duration and frequency of seizures in the research group were lower than those in the control group (p<0.05). The physiological function, physical pain, vital energy score and general health status in the research group were higher than those in the control group (p<0.05). The NT-ProBNP and CK-MB levels in both groups after treatment were decreased. CONCLUSION: Ticagrelor combined with aspirin has definite therapeutic effect on patients with coronary heart disease angina pectoris, with low prevalence of adverse reactions. It can significantly reduce the levels of NT-ProBNP and CK-MB, which is worthy of promotion.

Impact on survival of early detection of isolated breast recurrences after the primary treatment for breast cancer: a meta-analysis.

PURPOSE: The purpose was to establish the impact on survival of early detection of a local recurrence of breast cancer as compared to late detection. DESIGN: A meta-analysis was carried out using Cochrane review manager software (RevMan version 4.2). Studies were included if women were treated for primary breast cancer without evidence of distant metastasis at primary diagnosis and if these concerned routine follow-up strategies focusing on the early detection of curable recurrences. Data regarding the risk for death were derived from each study. Multi level models were used to study heterogeneity by using MLWin. RESULTS: Thirteen studies concerning 2,263 patients were included. Early detection of breast cancer recurrences during follow-up gave a significantly better survival as compared to late detected recurrences (HR: 1.68 (95% CI: 1.48-1.91)). Survival was better when the recurrence was found by mammography instead of physical examination or in patients without symptoms as compared to those with symptoms (HR: 2.44 (95% CI: 1.78-3.35); HR: 1.56 (95% CI: 1.36-1.79), respectively). If all breast cancer recurrences would be detected earlier, that 5-8 deaths (i.e. an absolute reduction in mortality of 17-28%) would be avoided by performing routine follow-up during a 10 year-period for 1,000 breast cancer patients. CONCLUSION: These data support the hypothesis that detection of isolated loco-regional or contra-lateral breast cancer recurrences in patients without symptoms has beneficial impact on survival of breast cancer patients when compared to late symptomatic detection.

[Changing trend regarding the burden on cerebrovascular diseases between 1990 and 2016 in China].

Objectives: To analyze the status quo and trends on the burden of cerebrovascular diseases between 1990 and 2016 in China. Methods: Morbidity mortality, years of life lost (YLL), years of lived with disability (YLD) and disability-adjusted life year (DALY) related to cerebrovascular diseases between 1990 and 2016, were collated and analyzed, according to the results of the Global Burden of Diseases Study 2016 (GBD 2016). Numbers on incidence and morbidity were used to assess the incidence of diseases, while the numbers of death and mortality were used to assess the death of diseases. Years of life lost due to premature death (YLL), years lost due to disability (YLD) and disability-adjusted life year (DALY) were used to assess the burden of diseases. Changing trend on the burden of cerebrovascular disease from 1990 to 2016 was also analyzed. Results: In 2016 and 1990, the numbers of new cases/morbidity and the number of deaths/mortality on cerebrovascular diseases in the country showed an upward trend. Rates regarding YLL and DALY on cerebrovascular diseases remained stable from 1990 to 2016, however, the YLD rate showed a slow upward trend. The changing rate of DALY was mainly influenced by YLL. Both DALY and YLL crude rates in males showed a slow upward trend, with the highest DALY rate appearing in the ≥70 age group. Disease burden on males was heavier than that of the females and in the 50-60 age group, which taking the largest proportion. As for the composition in DALY, YLL appearing much larger than YLD and slowly increasing. Analysis on the subtypes of diseases, proportions of YLL and DALY in hemorrhagic stroke were greater than that in ischemic stroke while the proportion of YLD in ischemic stroke was in the opposite. Conclusions: The burden of disease on cerebrovascular diseases remained heavy and the differences appeared in age, gender and subtypes of diseases. Our findings called for the adoption of measures including screening, intervention and rehabilitation to be taken on target populations, in order to reduce the burden on both individuals and the society.

[Analysis of clinical features and related genes variation in five patients with 46, XX male syndrome].

Objective: To explore the clinical manifestations and molecular features of 46, XX male syndrome. Method: The clinical and molecular data of five 46, XX male syndrome cases treated in the Department of Pediatrics of Shanghai Ruijin Hospital form August 2010 to August 2014 were retrospectively analyzed. Result: The five patients were all sociopsychologically males and came to hospital respectively for short stature, ambiguous genitalia or gynecomastia. They were all below the normal male's average height, and their karyotype was all 46, XX. One case in five was verified as sex determining region of Y chromosome (SRY gene) positive revealed no abnormality in their external genitalia. He had short stature since childhood, whose SRY gene fragments were shown by FISH transferred to the ends of X chromosome. Three cases in four were SRY gene negative with ambiguous genitalia of cryptorchidism and testicular dysplasia to different degrees. The copy number variations of SOX9 gene was found in one case, the loss of heterozygosity area in DHH gene of one case. Another SRY gene negative patient who had normal male external genitalia, came to the hospital due to puberty gynecomastia, that of SOX9 gene and its upstream gene both increased. Conclusion: The main clinical characteristics of 46, XX male syndrome are male phenotype, 46, XX karyotype, gonad of testis or ovotestis and no uterus. In addition, short stature, ambiguous genitalia or gynecomastia can be one reason for hospital visits. SRY gene translocation, SOX9 gene and its upstream gene copy number increase all can lead to 46, XX male syndrome. The cause of some may play an important role in 46, XX male syndrome, but has not yet been determined.

Effects of anodic titanium dioxide nanotubes of different diameters on macrophage secretion and expression of cytokines and chemokines.

OBJECTIVES: To investigate effects of TiO2 nanotubes of different diameters on J744A.1 macrophage behaviour, secretion and expression of pro-inflammatory cytokines and chemokines. MATERIALS AND METHODS: Macrophage-like J744A.1 cells were cultured on three types of Ti surface: mechanically polished titanium plus 30 and 80 nm TiO2 nanotube surfaces, for 4, 24 and 48 h. Macrophage adhesion and proliferation were assessed using CCK-8 assay. Levels of pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6) and chemokines (MCP-1 and MIP-1α) secreted into the supernatant were measured using the Cytometric Bead Arrays kit. TNF-α, MCP-1 and MIP-1α gene expression were quantitatively analysed by real-time PCR. RESULTS: These show that TiO2 nanotube surfaces, especially of 80 nm TiO2 nanotube, benefited macrophage adhesion and proliferation, and reduced protein secretion and mRNA expression of TNF-α, MCP-1 and MIP-1α. IL-1ß and IL-6 were undetectable on all the surfaces at all times. CONCLUSIONS: TiO2 nanotube surfaces, especially of 80 nm TiO2 nanotube, reduced inflammatory response in vitro, which might be part of a basis for rapid osseointegration in implants with TiO2 nanotube surfaces in animal studies.

[A new dynamic model of release for not-corroded drug system--revision and use of Fick's first law].

Based on the facts that the diffusion coefficient in original Fick's first law is not a strict constant but changes with concentration and that the original Fick's first law is only suitable for the stable diffusion with constant concentration gradient but many experiments have shown that the concentration gradient is a function of time. The authors suggest that the diffusion coefficient and the concentration gradient should be revised, respectively, as a concentration function and a time function. That is, [formula: see text] So, the Fick's first law is revised as [formula: see text] In the formula, dW/dt represents the rate of diffusion. D0 is the intrinsic diffusion coefficient that is a constant only concerning the temperature and the character of the substance diffused. A is the area of diffusion surface, alpha is the constant concerning the change of concentration gradient, C0 and C is, respectively, the concentration on the diffusion surface at time t0 and any time t. Based on this, the dynamic model of release on the preparations not-corroded is derived: [formula: see text] Here, k0 is the release constant concerning D0, temperature, C0 and A. The model gave better results than other models in common use for simulating the release dynamic process and the physical meanings of the model parameters are explicit.

The increase of the functional entropy of the human brain with age.

We use entropy to characterize intrinsic ageing properties of the human brain. Analysis of fMRI data from a large dataset of individuals, using resting state BOLD signals, demonstrated that a functional entropy associated with brain activity increases with age. During an average lifespan, the entropy, which was calculated from a population of individuals, increased by approximately 0.1 bits, due to correlations in BOLD activity becoming more widely distributed. We attribute this to the number of excitatory neurons and the excitatory conductance decreasing with age. Incorporating these properties into a computational model leads to quantitatively similar results to the fMRI data. Our dataset involved males and females and we found significant differences between them. The entropy of males at birth was lower than that of females. However, the entropies of the two sexes increase at different rates, and intersect at approximately 50 years; after this age, males have a larger entropy.

Effect of stealthy liposomal topotecan plus amlodipine on the multidrug-resistant leukaemia cells in vitro and xenograft in mice.

BACKGROUND: Multidrug resistance (MDR) is a major obstacle to successful cancer chemotherapy as the over-expressed MDR protein acts as an efflux pump, which leads to a reduction in the uptake of the anticancer agent by tumour cells. We combined topotecan and amlodipine together into the stealthy liposomes, in which amlodipine was applied as a MDR reversing agent to overcome the resistance. MATERIALS AND METHODS: Cytotoxicity, apoptosis and the signalling pathway assays were performed on human chronic myelogenous leukaemia K562, promyelocytic leukaemia HL-60 and MDR HL-60 cells, respectively. Pharmacokinetics and antitumour activity studies were performed on normal Kunming mice and female BALB/c nude mice with MDR HL-60 xenografts, respectively. RESULTS: Topotecan alone was effective in inhibiting the growth of non-resistant leukaemia cells, K562 and HL-60 cells but not the growth of MDR HL-60 cells. The resistance of topotecan in MDR HL-60 cells was potently reversed by the addition of amlodipine. Moreover, amlodipine enhanced the apoptosis-inducing effect of topotecan synergistically. Apoptosis was through activating caspases in a cascade: first, the initiator caspase 8 and then effectors caspase 3/7 (total activity of caspases 3 and 7) were activated. Being encapsulated into the stealthy liposomes with an acidic internal medium, topotecan existed dominantly in an active lactone species, which was reversibly changed from an inactive carboxylate form via a pH-dependent reaction. After administration of stealthy liposomes to mice, the blood exposure of the lactone form was evidently increased and extended. The antitumour effects in the MDR HL-60 xenografted tumour were stealthy liposomal topotecan (SLT) plus amlodipine > SLT > un-encapsulated topotecan > blank control. CONCLUSIONS: The enhanced antitumour activity in the MDR HL-60 cells by the SLT plus amlodipine could be owing to multiple reasons: (a) synergistic apoptosis inducing effect, (b) reversing MDR by amlodipine and (c) increasing the availability of active lactone of topotecan by the stealthy liposomes. The apoptosis induced by amlodipine is through caspase 8 and then the 3/7 signalling pathway.

In vitro and in vivo study of two types of long-circulating solid lipid nanoparticles containing paclitaxel.

Paclitaxel (Taxol), a diterpenoid isolated from Taxus brevifolia, is effective against several murine tumors, and is one of the most exciting anticancer molecules currently available. Due to its low solubility in water, it is clinically administered with polyethoxylated castor oil (Cremophor EL), which causes serious side effects. Inclusion of paclitaxel in solid lipid nanoparticles (SLNs) has proved to be a good approach to eliminate the need for Cremophor EL and improve the drug's antitumor efficacy. This paper describes the development of two types of long-circulating SLNs as colloidal carriers for paclitaxel. SLNs are constituted mainly of bioacceptable and biodegradable lipids. In vitro release kinetics showed that the release was very slow, the release of paclitaxel from F68-SLN is linear, and the release of paclitaxel from Brij78-SLN followed the Weibull equation. Pharmacokinetics was evaluated in KM mice after injection of paclitaxel formulated in Cremophor EL or in Brij78-SLN and F68-SLN. Encapsulation of paclitaxel in both SLNs produced marked differences compared with the free drug pharmacokinetics. F68-SLN and Brij78-SLN are long-circulating (t 1/2 beta, 10.06 and 4.88 h, respectively) compared with paclitaxel injection (t 1/2 beta, 1.36 h).