Pancreatic Serous Cystic Neoplasms and Mucinous Cystic Neoplasms: Differential Diagnosis by Combining Imaging Features and Enhanced CT Texture Analysis.

OBJECTIVE: To establish a diagnostic model by combining imaging features with enhanced CT texture analysis to differentiate pancreatic serous cystadenomas (SCNs) from pancreatic mucinous cystadenomas (MCNs). MATERIALS AND METHODS: Fifty-seven and 43 patients with pathology-confirmed SCNs and MCNs, respectively, from one center were analyzed and divided into a training cohort (n = 72) and an internal validation cohort (n = 28). An external validation cohort (n = 28) from another center was allocated. Demographic and radiological information were collected. The least absolute shrinkage and selection operator (LASSO) and recursive feature elimination linear support vector machine (RFE_LinearSVC) were implemented to select significant features. Multivariable logistic regression algorithms were conducted for model construction. Receiver operating characteristic (ROC) curves for the models were evaluated, and their prediction efficiency was quantified by the area under the curve (AUC), 95% confidence interval (95% CI), sensitivity and specificity. RESULTS: Following multivariable logistic regression analysis, the AUC was 0.932 and 0.887, the sensitivity was 87.5% and 90%, and the specificity was 82.4% and 84.6% with the training and validation cohorts, respectively, for the model combining radiological features and CT texture features. For the model based on radiological features alone, the AUC was 0.84 and 0.91, the sensitivity was 75% and 66.7%, and the specificity was 82.4% and 77% with the training and validation cohorts, respectively. CONCLUSION: This study showed that a logistic model combining radiological features and CT texture features is more effective in distinguishing SCNs from MCNs of the pancreas than a model based on radiological features alone.

[Inhibitory effects of emodin on proliferation of rat vascular smooth muscle cell induced by angiotensin II].

OBJECTIVE: To investigate the effects of emodin on the proliferation of cultured rat vascular smooth muscle cell (VSMC) induced by angiotensin II. METHOD: VSMCs were cultured by explant method. Cell proliferation model was established by stimulation with Ang II. Cell proliferation was measured by MTT assay to observe the effects of emodin (10, 20, 40 and 80 micromol x L(-1)) and N(G)-nitro-L-arginine methyl ester (L-NAME, 100 micromol x L(-1)) on VSMC proliferation induced by Ang II. The expression of PCNA was measured by immunohistochemical staining. Nitric oxide (NO) level was measured by Griess reagent. Nitric oxide synthase (NOS) and inducible nitric oxide synthase (iNOS) levels were detected by chemical colorimetric method. mRNA expression of iNOS was measured by reverse transcription polymerase chain reaction (RT-PCR). RESULT: Emodin at the doses range from 10 to 80 mol x L(-1) inhibited cell proliferation in a dose and time-dependent manner. The inhibitory effects were partly blocked by 100 mol x L(-1) of L-NAME. Emodin markedly decreased the expression of PCNA in VSMC, increased NO, NOS and iNOS levels, and increased iNOS mRNA expression in VSMC. CONCLUSION: Emodin could inhibite VSMCs proliferation induced by Ang II. Inhibiting the expression of PCNA, increasing the NO secretion and upregulating the iNOS gene expression might be associated with the inhibitory effects.

[Apoptosis and ultrastructural lesions in Vero and J774A.1 cells induced by Leptospira interrogans].

OBJECTIVE: To determine the ability of adhering and invading to host cells and the related pathologic changes of Leptospira spp. with different virulence. METHODS: A special Fontana silver staining method was developed to observe the ability of L.interrogans serogroup Icterohaemorrhagiae serovar lai strain 56601 and serogroup Pomona serovar pomona strain 56608, and L.biflexa serogroup Samaranga serovar patoc strain Patoc I to adhere Vero and J774A.1 cells. Ultrastructural lesions of the infected cells were examined by electron microscopy. By using flow cytometry with fluorescein labeling of FITC-Annexin V/PI,apoptosis and necrosis of the Vero and J774A.1 cells induced by the leptospiral strains before and after inactivation with ultraviolet treatment were detected, respectively. RESULTS: The adhering rates of L.interrogans strains 56601 and 56608 to the Vero cells were 24.2% and 22.9% (P>0.05), while to the J774A.1 cells were 49.0% and 46.9% (P>0.05), respectively. L.biflexa strain Patoc I did not adhere to these two host cells. After the two strains of L.interrogans invaded two different cell lines, the special phagosomes containing the Leptospira were formed and similar cell ultrastructural lesions, such as chromatilysis and chromatin condensation, vacuolar degeneration, mitochondrion swelling and mitochondrial crista disappearance, and endoplasmic reticulum swelling and paramembranous ribosome disappearance, were observed. The apoptosis rates in the Vero cells caused by the L.interrogans strains 56601 and 56608 before and after ultraviolet inactivation were 84.4%, 82.8% and 77.9%, 86.1%, respectively. The L.interrogans strain 56601 mainly induced the terminal apoptosis in Vero cells with the rates of 68.0% and 52.9% before or after inactivation, while the L.interrogans strain 56608 mainly induced the early apoptosis in Vero cells with apoptosis rates of 64.1% and 50.1% before or after inactivation. In the J774A.1 cells, the L.interrogans strain 56608 caused cell necrosis (before and after inactivation) and apoptosis that was dominated by terminal apoptosis. CONCLUSION: The established Fontana silver staining method can be used to observe adhesion of L.interrogans.L.interrogans can invade host cells through endocytosis which causes untrastructural lesions. The necrosis or apoptosis induced by L.interrogans are affected by different host cell lines but not the virulence of L.interrogans strains.