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211.
International Journal of Peptide Research and Therapeutics - The current COVID-19 pandemic is one of the most devastating events in recent history. The respiratory effects of this disease include...  相似文献   
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213.
Xanthomonas genus possesses a low level of β-galactosidase gene expression and is therefore unable to produce xanthan gum in lactose-based media. In this study, we report the emergence of some natural field strains of Xanthomonas citri subsp. citri (Xcc) capable to use lactose as a sole carbon source to produce xanthan gum. From 210 Xcc strains isolated from key lime (C. aurantifolia), 27 showed the capacity to grow on lactose containing medium. Xcc lactose consuming strains demonstrated a good level of xanthan production. Amongst all, NIGEBK37 produced the greatest (14.62 g/l) amount of xanthan gum in experimental laboratory conditions. By evaluating the viscosity of the biopolymer at 25 °C, it was demonstrated that xanthan synthesized by strain NIGEBK37 has the highest viscosity (44,170.66 cP). Our results were indicative for the weakness of a commercial strain of Xanthomonas campestris pv. Campestris DSM1706 (Xcc/DSM1706) to produce xanthan in lactose containing medium.  相似文献   
214.
Background:Stem cell differentiation therapy is a promising strategy in cancer treatment. we show that protein cocktail prepared from serum starved fibroblasts has therapeutic potential based on this strategy. Methods:The condition medium was prepared from foreskin isolated fibroblasts and analyzed by Liquid chromatography electrospray ionization mass spectrometry-mass spectrometry (LC-ESI-MS/MS). LA7 mammary gland cancer stem cells originated tumors were induced in Sprague Dawley rats. The rats treated subcutaneously with DMEM (group A), condition medium (group B), or normal saline (group C) once daily for 7 days. Then the tumors were removed and divided into the two parts, one part was used to quantify gene expression by stem-loop RT-qPCR assay and the other part was used for Hematoxylin & Eosin (H & E), Giemsa, and immunohistochemistry (IHC) staining.Results:All induced tumors appeared as sarcomatoid carcinoma (SC). Immunohistochemistry staining confirmed this conclusion by recognizing the tumor as Ki67+, cytokeratin+, vimentine+, and estrogen receptor negative SC. RT-qPCR analysis revealed that Oct4-, Sox-2, Nanog- gene expression was much reduced in the condition medium treated tumors versus proper controls (p< 0.05). Tissue necrosis was more prevalent in this group while tumors volume was diminished almost by 40%. The LC-ESI-MS/MS analysis unrevealed the stemness reducing and the cell death inducing proteins such as, pigment epithelium-derived factor (PEDF), insulin like growth factor binding protein-5 (IGFBP-5) and -7 (IGFBP-7) in the condition medium.Conclusion:This study showed that the substances released from starved human fibroblasts were able to down-regulate the stemness-related genes and induce necrosis in LA7 derived tumors.Key Words: Breast cancer, Cancer Stem cells, Cell differentiation, Fibroblasts, Gene expression  相似文献   
215.
The dynamics of tumor growth and associated events cover multiple time and spatial scales, generally including extracellular, cellular and intracellular modifications. The main goal of this study is to model the biological and physical behavior of tumor evolution in presence of normal healthy tissue, considering a variety of events involved in the process. These include hyper and hypoactivation of signaling pathways during tumor growth, vessels’ growth, intratumoral vascularization and competition of cancer cells with healthy host tissue. The work addresses two distinctive phases in tumor development—the avascular and vascular phases—and in each stage two cases are considered—with and without normal healthy cells. The tumor growth rate increases considerably as closed vessel loops (anastomoses) form around the tumor cells resulting from tumor induced vascularization. When taking into account the host tissue around the tumor, the results show that competition between normal cells and cancer cells leads to the formation of a hypoxic tumor core within a relatively short period of time. Moreover, a dense intratumoral vascular network is formed throughout the entire lesion as a sign of a high malignancy grade, which is consistent with reported experimental data for several types of solid carcinomas. In comparison with other mathematical models of tumor development, in this work we introduce a multiscale simulation that models the cellular interactions and cell behavior as a consequence of the activation of oncogenes and deactivation of gene signaling pathways within each cell. Simulating a therapy that blocks relevant signaling pathways results in the prevention of further tumor growth and leads to an expressive decrease in its size (82% in the simulation).  相似文献   
216.

Background

Coronary artery disease is the leading cause of death in industrialized countries and most patients with diabetes die from complications of atherosclerosis. The objective of this study was to determine the presence of diabetes mellitus and other conventional coronary heart disease risk factors (cigarette smoking, hypertension and hyperlipidemia) in patients with acute coronary events in an Iranian population.

Methods

The study included 514 patients with unstable angina or myocardial infarction (MI) out of 720 patients admitted to CCU ward of a general hospital from March 2003 to March 2005. History of diabetes, hypertension and cigarette smoking, demographic indices, coronary heart disease and diabetes mellitus treatment, myocardial enzymes, serum triglycerides (TG) and cholesterol and fasting and non fasting blood glucose levels and HbA1C of diabetics were recorded of admission sheets. The data were structured to appropriate one way ANOVA, T tests, and chi square test with SPSS 13 product for windows.

Results

Out of all patients 35.8% were female, 30% were diabetics (Duration 13.4 ± 8.7 years), 42% were smoker and 91% were hypertensive. Twenty four percent had MI and 76% had unstable angina. MI was significantly higher in diabetic patients (36.4% vs. 19.2%, P < 0.001). Location and extension of MI and myocardial enzymes did not differ between diabetics and non-diabetic patients. Diabetic patients were older than non diabetics (65 ± 11.6 vs. 59.7 ± 12.5 years, p < 0.05). Five (66.7%) out of 9 patients with fatal MI were diabetics (Odds Ratio = 2.98). Age, duration of diabetes and HbA1c levels, did not differ between diabetic patients with or without MI. Hypertension and current smoking was significantly higher in patients with MI compared to patients with unstable angina (p < 0.05). Serum TG, HDL-C, LDL-C and total cholesterol level did not differ between patients with MI and unstable angina. Diabetic patients compare to non diabetic patients were more hypertensive (96% vs. 88.7%, p < 0.005) and had higher serum triglyceride (TG over 200 mg/dl, 35.1% vs. 26.4, p <0.05). Diabetes was more frequent among women than men (36.4% vs. 26.4%, p < 0.05). Women were older than men (65 ± 11.6 vs. 59.2 ± 13 years, p < 0.005) and had higher total serum cholesterol (200 ± 41.8 vs. 192 ± 42.5 mg/dl, p < 0.05) and HDL-C levels (49.7 ± 22 vs. 40 ± 13 mg/dl, p < 0.005). Ninety seven percent of all patients had at least one of cardiovascular risk factors (hypertension, smoking, diabetes, high cholesterol and low HDL-cholesterol levels).

Conclusion

In this study 19 out of 20 patients with acute coronary event have at least one of conventional cardiac risk factors. Diabetes and hypertension are leading risk factors, which may directly or indirectly interfere and predict more serious complications of coronary heart disease.  相似文献   
217.
Chimeric proteins are composed of a cell-targeting moiety and a cell-killing moiety. In this study, a chimeric protein, STXA1-GM-CSF, composed of catalytic domain of Shiga toxin (A1) and granulocyte-macrophage colony-stimulating factor (GM-CSF) was constructed and expressed in E. coli. Cytotoxicity, receptor blocking, and neutralization experiments revealed that the chimeric protein induced cytotoxic effect on different cell lines. This effect was found to be specific, due to the presence of the killing moiety (A1), which exerts its effect through a specific GM-CSF-targeting domain, by binding to its receptor present on those cell lines. These initial investigations indicate that the chimeric protein was functional; further analyses are required for its application.  相似文献   
218.
A group of 4-methoxyphenylacetic acid esters were designed, synthesized and evaluated as potential inhibitors of soybean 15-lipoxygenase (SLO) on the basis of eugenol and esteragol structures. Compounds 7de showed the best IC50 in SLO inhibition (IC50 = 3.8 and 1.9 μM, respectively). All compounds were docked in SLO active site and showed that carbonyl group of compounds is oriented toward the FeIII–OH moiety in the active site of enzyme and fixed by hydrogen bonding with hydroxyl group. It is assumed that lipophilic interaction of ligand–enzyme would be in charge of inhibiting the enzyme activity. The selectivity of the synthetic esters in inhibiting of 15-HLOb was also compared with 15-HLOa by molecular modeling and multiple alignment techniques.  相似文献   
219.
Aims Effects of insulin and ascorbic acid on expression of Bcl-2 family proteins and caspase-3 activity in hippocampus of diabetic rats were evaluated in this study. Methods Diabetes was induced in Wistar male rats by streptozotocin (STZ). Six weeks after verification of diabetes, the animals were treated for 2 weeks with insulin or/and ascorbic acid in separate groups. Hippocampi of rats were removed and evaluation of Bcl-2, Bcl-xL, and Bax proteins expression in frozen hippocampi tissues were done by SDS-PAGE electrophoresis and blotting. The Bcl-2, Bcl-xL, and Bax proteins bands were visualized after incubation with specific antibodies using enhanced chemiluminescences method. Caspase-3 activity was determined using the caspase-3/CPP32 Fluorometric Assay Kit. Results Diabetic rats showed increase in Bax protein expression and decrease in Bcl-2 and Bcl-xL proteins expression. The Bax/Bcl-2 and Bax/Bcl-xL ratios were found higher compared with non-diabetic control group. Treatments with insulin and/or ascorbic acid were resulted in decrease in Bax protein expression and increase in Bcl-2 and Bcl-xL proteins expression. The Bcl-2/Bax and Bcl-xL/Bax ratios were found higher in treated groups than untreated diabetic group. Caspase-3 activity level was found higher in diabetic group compared with non-diabetic group. Treatment with insulin and ascorbic acid did downregulated caspase-3 activity. Conclusions Our data provide supportive evidence to demonstrate the antiapoptotic effects of insulin and ascorbic acid on hippocampus of STZ-induced diabetic rats.  相似文献   
220.

The optic nerve (ON) is a recently recognized tractional load on the eye during larger horizontal eye rotations. In order to understand the mechanical behavior of the eye during adduction, it is necessary to characterize material properties of the sclera, ON, and in particular its sheath. We performed tensile loading of specimens taken from fresh postmortem human eyes to characterize the range of variation in their biomechanical properties and determine the effect of preconditioning. We fitted reduced polynomial hyperelastic models to represent the nonlinear tensile behavior of the anterior, equatorial, posterior, and peripapillary sclera, as well as the ON and its sheath. For comparison, we analyzed tangent moduli in low and high strain regions to represent stiffness. Scleral stiffness generally decreased from anterior to posterior ocular regions. The ON had the lowest tangent modulus, but was surrounded by a much stiffer sheath. The low-strain hyperelastic behaviors of adjacent anatomical regions of the ON, ON sheath, and posterior sclera were similar as appropriate to avoid discontinuities at their boundaries. Regional stiffnesses within individual eyes were moderately correlated, implying that mechanical properties in one region of an eye do not reliably reflect properties of another region of that eye, and that potentially pathological combinations could occur in an eye if regional properties are discrepant. Preconditioning modestly stiffened ocular tissues, except peripapillary sclera that softened. The nonlinear mechanical behavior of posterior ocular tissues permits their stresses to match closely at low strains, although progressively increasing strain causes particularly great stress in the peripapillary region.

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