Evaluating overall survival and competing risks of survival in patients with early-stage breast cancer using a comprehensive nomogram.

BACKGROUND: Patients with early-stage breast cancer (BC) live long but have competing comorbidities. This study aimed to estimate the effect of cancer and other causes of death in patients with early-stage BC and further quantify the survival differences. MATERIALS AND METHODS: Data of patients diagnosed with BC between 2010 and 2016 were collected from the Surveillance, Epidemiology, and End Results database. The cumulative incidence function for breast cancer-specific mortality (BCSM) and other cause-specific mortality (OCSM) was estimated, and the differences were tested using the Gray test. The nomogram for estimating 3-, 4-, and 5-year overall survival (OS), breast cancer-specific survival, and other cause-specific survival was established based on Cox regression analysis and Fine and Gray competing risk analysis. The discriminative ability, calibration, and precision of the nomogram were evaluated and compared using C statistics, calibration plots, and area under the receiver operating characteristic curve. RESULTS: A total of 196 304 eligible patients with early-stage BC were identified in this study. Of these, 12 417 (6.3%) patients died: 5628 (45.3%) due to BC and 6789 (54.7%) due to other causes. Five validated variables were incorporated to develop the prognostic nomogram: age, grade, tumor size, subtype, and surgery of primary site (Figure 3). Age was a strong predictive factor, which was more obvious in OCSM. The effect of surgery was more prominent in BCSM. Increased tumor size was correlated with OS and BCSM and slightly correlated with OCSM. Grade and subtype differences were more predominant in BCSM than in OCSM. The established nomogram was well calibrated and displayed good discrimination. CONCLUSIONS: We evaluate OS and competing risks of death in patients with early-stage BC, establishing the first comprehensive prognostic nomogram.

Predictive value of a nomogram for melanomas with brain metastases at initial diagnosis.

BACKGROUND: Estimation of incidence and prognosis of melanomas with brain metastases (MBM) at initial diagnosis based on a large cohort is lacking in current research. This study aims to construct an effective prognostic nomogram for newly diagnosed MBM. MATERIALS AND METHODS: Patients diagnosed with melanomas from Surveillance, Epidemiology, and End Results program between 2010 and 2014 were enrolled in our study. Risk factors predicting brain metastases (BM) were identified using logistic regression analysis. Cox regression analysis was performed to identify prognostic factors of overall survival (OS). Nomogram for estimating 6-, 9-, and 12-month OS was established based on Cox regression analysis. The discriminative ability and calibration of the nomogram were tested using C statistics, calibration plots, and Kaplan-Meier curves. RESULTS: Sixty-two thousand three hundred and sixty-nine melanoma patients were enrolled, including 928 with BM. Sex, marital status, insurance status, subsite, surgery of primary sites, radiation, chemotherapy, bone metastases, liver metastases, and lung metastases were associated with MBM at initial diagnosis. On multivariable Cox regression, the following eight variables were incorporated in the prediction of OS: age, unmarried status, absence of surgery to primary sites or unknown, absence of radiation or unknown, absence of chemotherapy or unknown, with bone metastases, with liver metastases, and with lung metastases. The nomogram showed good predictive ability as indicated by discriminative ability and calibration, with the C statistics of 0.716 (95% CI, 0.695-0.737). CONCLUSIONS: The incidence and prognosis of MBM patients were well estimated in this study based on a large cohort. The nomogram performed well and could be a useful tool to predict prognosis.

Effects of three drying methods on the physical properties and drug delivery in chitosan microspheres / 华西口腔医学杂志

OBJECTIVE@#The purpose of this study is to investigate the effects of different drying methods on the physical properties and drug delivery of chitosan microspheres.@*METHODS@#Three types of drying methods were utilized, including air drying and freeze drying after freezing at -20 ℃ (slow cooling) and at -80 ℃ (fast cooling). The physical properties of microspheres were characterized. Utilizing bovine serum albumin (BSA) as the model drug, the in-vitro release behaviors of drug-loaded beads were investigated.@*RESULTS@#By comparing the physical properties of the different drying methods, the microspheres' diameters, porosities, and surface area were observed to increase successively from air drying and slow cooling to fast cooling, whereas the pore size and the swelling and degradation rates varied. The drug-loading experiments revealed that the loading capacity of air-dried microspheres was the lowest and the release rate was the slowest. Although the loading capacity of fast cooling microspheres was high, an obvious burst release was observed. The loading capacity of slow cooling microspheres was similar to that of the fast cooling microspheres and the loaded BSA can be released continuously.@*CONCLUSIONS@#The results indicate that different drying methods can affect the physical properties of chitosan microspheres, which further influence drug loading and release.

siRNA Knockdown of RRM2 Effectively Suppressed Pancreatic Tumor Growth Alone or Synergistically with Doxorubicin.

Pancreatic cancer is currently one of the deadliest of the solid malignancies, whose incidence and death rates are increasing consistently during the past 30 years. Ribonucleotide reductase (RR) is a rate-limiting enzyme that catalyzes the formation of deoxyribonucleotides from ribonucleotides, which are essential for DNA synthesis and replication. In this study, 23 small interfering RNAs (siRNAs) against RRM2, the second subunit of RR, were designed and screened, and one of them (termed siRRM2), with high potency and good RNase-resistant capability, was selected. Transfection of siRRM2 into PANC-1, a pancreatic cell line, dramatically repressed the formation of cell colonies by inducing remarkable cell-cycle arrest at S-phase. When combining with doxorubicin (DOX), siRRM2 improved the efficacy 4 times more than applying DOX alone, suggesting a synergistic effect of siRRM2 and DOX. Moreover, the combined application of siRRM2-loaded lipid nanoparticle and DOX significantly suppressed the tumor growth on the PANC-1 xenografted murine model. The inhibition efficiency revealed by tumor weight at the endpoint of the treatment reached more than 40%. Hence, siRRM2 effectively suppressed pancreatic tumor growth alone or synergistically with DOX. This study provides a feasible target gene, a drug-viable siRNA, and a promising therapeutic potential for the treatment of pancreatic cancer.

Pharmacokinetic Behaviors of Intravenously Administered siRNA in Glandular Tissues.

The pharmacokinetics of small interfering RNAs (siRNAs) is a pivotal issue for siRNA-based drug development. In this study, we comprehensively investigated the behavior of siRNAs in vivo in various tissues and demonstrated that intravenously-injected naked siRNA accumulated remarkably in the submandibular gland, bulbourethral gland, and pancreas, with a respective half-life of ~22.7, ~45.6, and ~30.3 h. This was further confirmed by gel separation of tissue homogenates and/or supernatants. In vivo imaging and cryosectioning suggested that delivery carriers significantly influence the distribution and elimination profiles of siRNA. Gene-silencing assays revealed that neither naked nor liposome-formulated siRNA resulted in gene knockdown in the submandibular and bulbourethral glands after systemic administration, suggesting that these glands function as drug reservoirs that enable slow siRNA release into the circulation. But robust gene-silencing was achieved by local injection of liposome-encapsulated siRNA into the submandibular gland. Our results enhance understanding of the pharmacokinetic properties of siRNAs and we believe that they will facilitate the development of siRNA therapy, especially for the submandibular gland.

Systemic and tumor-targeted delivery of siRNA by cyclic NGR and isoDGR motif-containing peptides.

The drug development of siRNA has been seriously hindered by the lack of an effective, safe and clinically applicable delivery system. The cyclic NGR motif and its isomerization product isoDGR recruit CD13 and integrin as their specific receptors, both of which are overexpressed by tumor and neovascular cells. In this study, a bi-functional peptide, named NGR-10R, was designed and tested for siRNA delivery in vitro and in vivo. Through the formation of peptide/siRNA nanoparticles, RNase resistance was greatly enhanced for the siRNAs. Both FACS and confocal assays revealed that the peptide/siRNA complexes were effectively internalized by MDA-MB-231 cells. Gene silencing assays indicated that anti-Lamin A/C siRNA delivered by NGR-10R robustly repressed gene expression in MDA-MB-231 and HUVEC (a CD13(+)/αvß3(+) cell). Importantly, the siRNAs were efficiently delivered into tumor tissues and localized around the nuclei, as revealed by in vivo imaging and cryosection examination. In summary, NGR-10R not only efficiently delivered siRNAs into MDA-MB-231 cells in vitro but also delivered siRNAs into tumor cells in vivo, taking advantage of its specific binding to CD13 (neovascular) or αvß3 (MDA-MB-231). Therefore, the NGR-10R peptide provides a promising siRNA delivery reagent that could be used for drug development, particularly for anti-tumor therapeutics.

[The construction and application of a novel apparatus for detecting oxygen consumption of mice under normobaric hypoxia].

OBJECTIVE: To establish a method for real-time recording the oxygen consumption of mice under normobaric hypoxia. METHODS: The experimental apparatus was made up of animal container, filling water control system, electronic balance, hose, a computer with weight recording software, etc. The working principle was that the oxygen consumed by animal was replaced by water filling which was controlled by the pneumatic and hydraulic actuator. The water was weighted by an electronic balance and the weight signal was recorded into excel file at the same time. The accuracy and precision of the apparatus were detected by a 10 ml syringe. The oxygen consumption characteristics of 6 acute repetitive hypoxia mice and 6 normal mice were observed. RESULTS: The P value for the paired t test was 1 and the CV value was 4%. The survival time and total oxygen consumption of acute repetitive hypoxia mice were both significantly increased compared to normal mice (P < 0.05), which were (58.8 +/- 6.8) min and (46.0 +/- 8.7) min respectively for the survival time and (85.1 +/- 8.5) ml and (73.6 +/- 5.4) ml respectively for total oxygen consumption. CONCLUSION: The hypoxia tolerance of the acute repetitive hypoxia mice can significantly improved by taking more oxygen in the animal cabin. The accuracy and precision of the apparatus are high and it can be used for the determination of oxygen consumption in hypoxia research.

Bonding interfaces of three kinds of cements and root canal dentin: a scanning electron microscope observation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the bonding properties of three kinds of cements by observing the bonding inteffaces of cements and root canal dentin.</p><p><b>METHODS</b>15 extracted mandibular premolars were divided into 3 groups, and were cemented by Rely X luting, Panavia F and Paracore 5 mL, respectively. Each tooth was sectioned into two parts and the dentin-cement interfaces at the coronal, middle and apical parts of the fiber post were oberved by scanning electron microscope (SEM). The length of hybrid layer was also recorded.</p><p><b>RESULTS</b>Hybrid layer was not clearly found in group one, which could be seen on the dentin-cement interfaces of group two and three. Resin tags and lateral adhesives were also observed in group three. From the apical to the coronal part, microgaps seemed gradually smaller in group one, while the hybrid layer became thicker in both group two and three.</p><p><b>CONCLUSION</b>The total-etch resin cement bounds tightly with dentin, and owns a more superior bonding property than self-etch resin cement and resin modified glass ionomer cement.</p>