Insulin-like growth factor I reduces the occurrence of necrotizing enterocolitis by reducing inflammatory response and protecting intestinal mucosal barrier in neonatal rats model.

OBJECTIVE: To observe the effect of enteral supplement of insulin-like growth factor I (IGF-1) on dynamic changes of TLR4, NF-κB, IL-6, SIgA and MUC2 in intestinal tissues of neonatal rats, and to investigate the protective effects and possible mechanisms of IGF-1 on necrotizing enterocolitis (NEC). MATERIALS AND METHODS: Specific pathogen free (SPF) neonatal Sprague Dawley (SD) rats aged 3 days old were randomly divided into 3 groups, namely, normal control group, NEC model group and IGF-1 intervention group. In NEC group, the neonatal NEC rat models were established using artificial feeding, hypoxia and cold stimulation. In IGF-1 intervention group, the models were established by means of artificial feeding plus hypoxia and cold stimulation, and IGF-1 (22 ug/L) at a physiological concentration similar to the breast milk was added to milk replacer for intervention. The rats in the three groups were killed after the blood was collected from the heart at 24, 48 and 72 h, respectively, following the establishment of models; then, 3 cm of the terminal ilea were dissected and used for histopathological examination, RT-PCR and ELISA studies after hematoxylin and eosin (HE) staining. RESULTS: Symptoms in IGF-1 intervention group were significantly relieved, and the incidence rate of NEC was lowered remarkably. In NEC model group, the peak expression of TLR4 mRNA occurred later than that of NF-κB mRNA and IL-6, and the expressions of TLR4 mRNA, NF-κB mRNA and IL-6 were decreased at 72 h after IGF-1 intervention. In NEC model group, the expression of MUC2 showed a transient decrease, the expression of SIgA was on the decline, but the expressions of MUC2 and SIgA were increased after IGF-1 intervention. CONCLUSIONS: The enteral administration of IGF-1 at a physiological concentration can ameliorate the clinical symptoms in neonatal NEC rat models and decrease the occurrence rate. The possible mechanism is that IGF-1 down-regulates the TLR4 mRNA expression to inhibit the production of inflammatory mediators, and it up-regulates the expressions of MUC2 and SIgA to protect the mechanical and immuno-barrier functions of the intestinal mucous.

Production of secoisolariciresinol from defatted flaxseed by bacterial biotransformation.

AIMS: Secoisolariciresinol (SECO) is increasingly recognized for potential clinical application because of its preventive effects against breast and colon cancers, atherosclerosis and diabetes, and its production through biotransformation has been attempted. However, previously reported bacteria all required stringent anaerobic culture conditions, precluding large-scale production. Here, we report the isolation and characterization of bacteria that produce SECO under less stringent anaerobic culture conditions. METHODS AND RESULTS: Using defatted flaxseed as raw material, we isolated a facultative anaerobic bacterium from human faeces that hydrolysed secoisolariciresinol diglucoside-3-hydroxy-3-methyl glutaric acid (SDG-HMGA) oligomers in flaxseed to produce SECO. Both conventional assays and 16S rRNA gene sequence analysis demonstrated its close relatedness with Bacteroides uniformis. The transformation efficiency of SDG in defatted flaxseed to SECO was more than 80% by this bacterial strain. We investigated factors that might influence fermentation, such as redox potential and pH, for large-scale fermentation of defatted flaxseed to produce SECO. CONCLUSIONS: The method to produce SECO through biotransformation of defatted flaxseed with this bacterial strain is highly efficient and economic. SIGNIFICANCE AND IMPACT OF THE STUDY: This bacterial strain can transform SDG to SECO under less stringent anaerobic culture conditions, which will greatly facilitate industry-scale production of SECO.

Identification of infarct core and penumbra in acute stroke using CT perfusion source images.

BACKGROUND AND PURPOSE: CT perfusion (CTP) mapping has been reported to be useful in the differentiation of the infarct core and ischemic penumbra. However, the value of the CTP source imaging (CTP-SI) during the arterial and venous phases has not been fully investigated. The purpose of this study was to develop a CTP-SI methodology for acute ischemic stroke and compare its efficacy with cerebral blood flow (CBF) and cerebral blood volume (CBV) in predicting infarct core and penumbra. MATERIALS AND METHODS: CT examinations, including non-contrast-enhanced CT, CTP, and CT angiography (CTA), were performed in 42 patients with symptoms of stroke for <9 hours. The Alberta Stroke Program Early CT Score (ASPECTS) was analyzed on the arterial phase CTP-SI and venous phase CTP-SI and then compared with the ASPECTS on CBF and CBV for efficacy assessment. RESULTS: The ASPECTS on the arterial phase CTP-SI was closely correlated with the ASPECTS on CBF, the Pearson correlation coefficient was 0.88 (P < .001), and the concordance correlation coefficient was 0.7603 (95% confidence interval [CI], 0.6331-0.8476). The ASPECTS on the venous phase CTP-SI revealed a significant correlation with the ASPECTS on CBV, the Pearson correlation coefficient was 0.92 (P < .001), and the concordance correlation coefficient was 0.8880 (95% CI, 0.8148-0.9334). Significant differences were shown between the arterial phase CTP-SI/ venous phase CTP-SI (P < .001) and CBF/CBV (P < .001). CONCLUSIONS: This study provides preliminary evidence that the arterial phase and venous phase CTP-SI mismatch model could possibly be applied to ischemic regions in the acute stage of stroke to determine penumbra and infarct core.

p73 expression and its clinical significance in colorectal cancer.

OBJECTIVE: To explore p73 mRNA and p73 protein expression and their clinical significance in colorectal cancer. METHOD: p73 mRNA and p73 protein expression were detected using hybridization in situ and immunohistochemical method in cancerous tissue from 60 patients of colorectal cancer and in paracancerous tissue from 23 patients among the corresponding 60 patients of colorectal cancer. Quantitative analysis was performed using Smartscape image analysis system. RESULTS: Compared with paracancerous tissue, p73 mRNA and p73 protein expression in cancerous tissue was increased with a statistically significant difference (P < 0.01) and was associated with differentiation level and lymphatic metastasis. CONCLUSION: High expression of p73 mRNA and p73 protein in colorectal cancer may be involved in the progression of colorectal cancer and p73 mRNA and p73 protein may serve as a potential index to predict differentiation level and prognosis of colorectal cancer.

Choroid plexus papillary carcinoma associated with hemorrhage. A case report.

Choroid plexus papillary carcinoma is a rare intracranial malignant epithelial tumor. We describe a case of choroid plexus tumor arising in the periventricular parenchyma. A 52-year-old man presented with headache for five months, aggravated by vomiting for three days. Brain computed tomography scan revealed an inhomogeneous density lesion in the right temporoparietal lobe with mild enhancement, and hemorrhage anterior to the lesion. Histological and immunohistochemical findings indicated a choroid plexus papillary carcinoma.

Dispersion and characteristic surfaces of waves in laminated composite circular cylindrical shells

The dispersion behaviors and characteristic surfaces of waves in a laminated composite circular cylindrical shell are investigated using a semianalytical method based on the theory of three-dimensional elasticity. The radial displacement of the shell is modeled by finite elements, while the axial and circumferential displacements are expanded as the complex exponentials. The associated characteristic equation is developed by means of the Hamilton's principle. The eigenvalues are established in terms of the Rayleigh quotient. Six characteristic wave surfaces, viz., the phase velocity, phase slowness, and phase wave surfaces, as well as the group velocity, group slowness, and group wave surfaces, are introduced to visualize the effects of anisotropy on wave propagation. Numerical examples demonstrate that the ratio of the inner radius to the thickness of the shell has a stronger influence on the frequency spectra in the circumferential wave than on that in the axial wave; that negative group velocity appears at a range of smaller wave numbers and the range varies as the wave normal and the ratio of the inner radius to the thickness of the shell; and that the characteristic wave surfaces vary with the propagation modes of waves, the ratio of the inner radius to the thickness of the shell, and the lay-ups of the laminated shells.

A strip-element method for analyzing wave scattering by a crack in an immersed axisymmetric laminated composite cylinder

A strip-element method is presented for analyzing wave scattering by a crack in a laminated composite cylinder immersed in a fluid. In this approach, two-nodal-line and three-nodal-line axisymmetric strip elements are employed to model the fluid and laminated cylinder, respectively. Governing equations for the fluid and solid elements in the frequency domain are derived with a variational method and the Hamilton principle. The associated characteristic equations in the wave-number domain are obtained through Fourier transform techniques. Responses of the fluid-loaded cylinder to a line load are found by a modal-analysis method and inverse Fourier transform techniques. Numerical results are presented for cracked laminated composite cylinders submerged in water. Water is found to have strong influence on the scattered wave fields in a cracked laminated composite cylinder.