A rat model of diabetic artery calcification

OBJECTIVES

The aim of this study was to develop a rat model that shares the similarities of calcification in diabetes.

METHODS

Male Wistar rats received a high-fat diet during 8 weeks followed by a low dose of streptozotocin. Half of them were treated with vitamin D3 and nicotine (VDN) 1 week after streptozotocin injection (DM) (DM+VDN). The others were treated with vehicle (DM). Arterial calcification was facilitated by vitamin D3 and nicotine in age-matched rats (VDN). Measurements of metabolic parameters, aortic calcium content, von Kossa staining, alkaline phosphatase activity and immunohistochemistry for osteopontin were performed. The expression of genes and proteins associated with calcification were also examined.

RESULTS

Treatment with VDN alone resulted in a small but not significant elevation of calcium content in aorta. However, in DM+VDN, aortic calcium content increased significantly as compared to the VDN. This calcification had also dramatically increased, as shown by von Kossa staining. Mechanistic studies revealed that addition of VDN treatment in diabetic rats enhanced both activity and mRNA expression of alkaline phosphatase. This treatment in diabetic- rats also enhanced the expression of core binding factor α 1 and its downstream protein osteopontin. In aorta, strong immunostaining for osteopontin was observed in DM+VDN. The result was also confirmed by Western blot analysis.

CONCLUSION

These results suggest that a model of accelerated arterial calcification in diabetes have been established and this model could be useful to investigate mechanisms related to vascular complication in diabetes.

Compliance with the CURB-65 score and the consequences of non-implementation

BACKGROUND

The CURB-65 (confusion, urea >7 mmol/l, respiratory rate ≥ 30 breaths/min, low blood pressure and age ≥ 65 years) score is a simple, well-validated tool for the assessment of severity in community-acquired pneumonia (CAP). It is unknown whether it is used routinely in China.

OBJECTIVE

To determine the frequency of use of the CURB-65 score in routine hospital practice and the consequences of non-implementation.

METHODS

A retrospective analysis of medical records from 1230 in-patients with CAP in a Chinese medical college-affiliated hospital.

RESULTS

No CAP patient underwent the CURB-65 test at admission. Based on the British Thoracic Society guidelines, the 716 (58.2%) in-patients with a CURB65 score of 0 and the 402 (32.7%) in-patients with CURB-65 score of 1 should have received ambulatory treatment, whereas the 14 (1.2%) patients with CURB65 scores of ≥ 3 should have been admitted to the critical care unit. The maximum excess total annual costs for managing CAP patients with CURB-65 scores of 0 and 1 were estimated at respectively US$94 383.12 and US$66 313.92 in the hospital.

CONCLUSIONS

The CURB-65 scoring tool in patients with CAP was not applied in routine hospital practice, resulting in inappropriate hospitalisation and excess costs.

[Size distribution properties of atmospheric aerosol particles during summer and autumn in Lanzhou]

Atmospheric particle size distributions (size range 0.5-20 microm) were measured using aerodynamic particle sizer (APS-3321) from August 1st to October 31st in Lanzhou. Variations of particle concentrations and properties of volume concentration distributions were analyzed through cluster analysis. The main objective of this study was to identify factors affecting the particle size distributions in Lanzhou. The hourly averaged particle number, surface area and volume concentrations are (108.1 +/- 92.2) cm(-3), (282.9 +/- 267.9) microm2 x cm(-3) and (92.2 +/- 127.3) microm3 x cm(-3), respectively. The number, surface area and volume concentrations of fine particles (0.5-2.5 microm) account for 98.7%, 73.8% and 52.9% of the total particle concentrations in 0.5-20 microm, respectively. The size distribution of number concentrations is unimodal with a peak at accumulation mode. The size distributions of surface area and volume concentrations are bimodal with peaks at accumulation mode and coarse mode, respectively. The size distributions of particle volume concentrations mainly have 7 clusters, indicating the effect of different sources and meteorological conditions. Coarse mode particles are dominant in particle volume size distributions affected by wind-borne dust and on dust days, while that affected by motor vehicle combustion emissions and traffic resuspended dust are characterized by bimodal with peaks at accumulation mode and coarse mode, respectively.

Emergence of resistance to fluoroquinolones and third-generation cephalosporins in Shigella flexneri subserotype 1c isolates from China

We report here on the first identification of Shigella flexneri subserotype 1c in China. We also report the emergence of resistance to ciprofloxacin and third-generation cephalosporins in this subserotype 1c for the first time. Isolates of seven strains circulating in China yielded three new sequence types and seven pulsed-field gel electrophoresis patterns, thus demonstrating the existence of high genetic diversity within the isolates. Overall, the seven isolates showed reduced susceptibility to ciprofloxacin; one isolate was ciprofloxacin resistant, whilst another developed resistance to ciprofloxacin, norfloxacin, cefotaxime and ceftriaxone.

P2-11-09: EGFR Overexpression in Triple Negative Breast Cancer (TNBC) and Its Association with the Prognosis

Objective: The aim of this study is to investigate EGFR expression in Triple Negative Breast Cancer (TNBC), and to find the relationship between EGFR overexpression and prognosis of TNBC, further to clarify the significance of EGFR in TNBC and provide valuable information for TNBC therapy.

Methods: 42 triple ***negandection ***ssitive breast cancer patients(studying group) and 40 HER2(3+) breast cancer patients(controling group) who underwent surgery from January 2000 to December 2005 were analyzed. 82 cases of paraffin-embedded specimens were detected by Immunohistochemistry(IHC), fluorescence in situ hybridization(FISH) and polymerase chain reaction(PCR) to investigate the overexpression, amplification and mutation of EGFR gene. The distant-free survival(DFS) and overall survival(OS) of these patients were used to investigate the relationship between EGFR overexpression and the prognosis of TNBC.

Results: 34(43.9%) EGFR overexpression was observed in all cases, while gene amplification was only 7(9.1%) cases. No EGFR gene mutation was found in all cases. Overexpression of EGFR occurring in 57.1% patients in TNBC group and 25.0% patients in HER2 group, and we didn't found any correlation between EGFR overexpression and clinicopathology. 50(61.0%) patients relapsed (TNBC 28,HER2 22) and 27(32.9%) patients died(TNBC 18,HER2 9) were observed during the more than 5 years follow-up. The 5-year DFS was 57.1% and 77.5% respectively, the 5-year OS was 71.4% and 87.5% in TNBC and HER2 groups. In TNBC group, the survival of the EGFR-overexpressing group patients was significantly lower than that of the non-EGFR-overexpressing group patients (p=0.018 for DFS, p=0.026 for OS); In HER2 group, no statistical difference was found (p=0.079 for DFS, p=0.055 for OS).

Conclusions: This study showed that EGFR overexpression increased significantly in TNBC patients, which was no correlation with their clinico-pathological data. EGFR gene amplification was much less frequent than its overexpression. It suggested that EGFR gene amplification may not be the unique mechanism of EGFR overexpression in TNBC. There may be other possible mechanisms and pathways that cause EGFR overexpression. In addition, it may suggest that gefitinib therapy is useless in TNBC patients because we did not find any mutations in the tested exons of TNBC. EGFR overexpression may associate with a poor outcome of TNBC patients which suggest it could be a significant prognostic factor for TNBC patients. EGFR may play important role for molecular-targeting therapy of TNBC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-11-09.

Antioxidative effects of whey protein on peroxide-induced cytotoxicity

Myoblastic toxicity is a major adverse effect caused by reactive oxygen species (ROS) when exercising heavily. Although protection or alleviation of ROS toxicity can be achieved by administration of antioxidant vitamins such as vitamin E and vitamin C, their protective effect remains controversial. Thus, alternative natural antioxidants may be potential candidates for foods for athletes. In this research, we investigated the antioxidative effect of whey protein against hydrogen peroxide (H(2)O(2)) toxicity using C(2)C(12) myoblasts. Whey protein pre-incubation prevented the decrease in cell viability after H(2)O(2) treatment. The production of 8-hydroxydeoxyguanosine associated with DNA oxidative damage was also inhibited by the whey protein pre-incubation. Endogenous antioxidant defense, such as glutathione, catalase, and superoxide dismutase activity, was also modulated by the antioxidant. At the same time, enhanced mRNA expression levels of heme oxygenase-1 and NADPH quinone oxidoreductase-1 were observed in cells pre-incubated with whey protein before H(2)O(2) abuse. These findings suggest that whey protein improved the antioxidant capacity against acute oxidative stress through multiple pathways and this protein may serve as an alternative source of antioxidants for prevention of athletic injuries caused by ROS.

Identification of neuroglobin-interacting proteins using yeast two-hybrid screening

Neuroglobin (Ngb) is a globin protein that is highly and specifically expressed in brain neurons. A large volume of evidence has proven that Ngb is a neuroprotective molecule against hypoxic/ischemic brain injury and other related neurological disorder; however, the underlying mechanisms remain poorly understood. Aiming to provide more clues in understanding the molecular mechanisms of Ngb's neuroprotection, we performed yeast two-hybrid screening to search for proteins that interact with Ngb. From a mouse brain cDNA library, we found totally 36 proteins that potentially interact with Ngb, and 10 of them were each identified in multiple positive clones. The shared sequences within these multiple clones are more likely to be Ngb-interacting domains. In primary cultured mouse cortical neurons, immuno-precipitation was performed to confirm the interactions of selected proteins with Ngb. The discovered Ngb-interacting proteins in this study include those involved in energy metabolism, mitochondria function, and signaling pathways for cell survival and proliferation. Our findings provide molecular targets for investigating protein interaction-based biological functions and neuroprotective mechanisms of Ngb.

A photo-multiplier tube-based hybrid MRI and frequency domain fluorescence tomography system for small animal imaging

Fluorescence tomography (FT) is a promising molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. However, recovered fluorophore parameters highly depend on the size and depth of the object due to the ill-posedness of the FT inverse problem. Structural a priori information from another high spatial resolution imaging modality has been demonstrated to significantly improve FT reconstruction accuracy. In this study, we have constructed a combined magnetic resonance imaging (MRI) and FT system for small animal imaging. A photo-multiplier tube is used as the detector to acquire frequency domain FT measurements. This is the first MR-compatible time-resolved FT system that can reconstruct both fluorescence concentration and lifetime maps simultaneously. The performance of the hybrid system is evaluated with phantom studies. Two different fluorophores, indocyanine green and 3-3' diethylthiatricarbocyanine iodide, which have similar excitation and emission spectra but different lifetimes, are utilized. The fluorescence concentration and lifetime maps are both reconstructed with and without the structural a priori information obtained from MRI for comparison. We show that the hybrid system can accurately recover both fluorescence intensity and lifetime within 10% error for two 4.2 mm-diameter cylindrical objects embedded in a 38 mm-diameter cylindrical phantom when MRI structural a priori information is utilized.

Differential effects of the calcitonin gene-related peptide on cardiac performance in acute myocardial ischemia and reperfusion in isolated rat hearts

BACKGROUND

The cardioprotective effects of the calcitonin gene-related peptide (CGRP) are known; however, the profiles of CGRP given pre- and postischemia as a therapeutic agent in acute myocardial ischemia and reperfusion remain elusive.

METHODS

The effects of CGRP on cardiac performance in isolated rat hearts subjected to 50 min global ischemia followed by 60 min reperfusion were investigated.

RESULTS

It was found that global ischemia and reperfusion significantly decreased left ventricular developed pressure (LVDP) and heart rate (HR) and elevated left ventricular end diastolic pressure (LVEDP). CGRP (10-7 mol/L) given before the ischemia caused significant increases in LVDP (38±9%, P<0.05) and HR (16±5%, P<0.05), compared to the control. CGRP (administered at the beginning of reperfusion) significantly reduced LVEDP and left ventricular systolic pressure (LVSP) compared to controls by 30±7% and 28±7%, respectively (P<0.05). When compared to the pre-ischemia treatment, LVEDP and LVSP were reduced by 20±7% and 26±7%, respectively (P<0.05). No significant changes in the LVDP and HR were detected when compared to the controls. The effects of CGRP could be reversed by CGRP8-37, a specific antagonist of the CGRP receptor.

CONCLUSION

The results indicated a differential effect of CGRP on cardiac performance following acute ischemia/reperfusion.

Effects of treadmill exercise on the expression of netrin-1 and its receptors in rat brain after cerebral ischemia

Recent evidence suggests that exercise improves functional outcome in animal models of cerebral ischemia. Since netrin-1 and its receptors, deleted in colorectal cancer (DCC) and uncoordinated gene 5B (Unc5B), act as important regulators in neural and vascular activities, we sought to determine whether netrin-1 and DCC and Unc5B are involved in the neuroprotective effects of exercise on rats with induced cerebral ischemia. A total of 108 rats were randomly distributed into three groups: sham-operated group (n = 12), middle cerebral artery occlusion (MCAO) group (n = 48), MCAO+treadmill exercise group (n = 48). Behavioral testing indicated that treadmill exercise could significantly improve neurologic deficits of rats with cerebral ischemia at day 14 and 28 after MCAO (n = 12, P<0.05 and P<0.01), but there was no significant difference at day 4 and 7. Quantitative reverse transcription polymerase chain reaction (qPCR) and Western blot analysis revealed that treadmill exercise enhanced netrin-1 and DCC expression, while it suppressed Unc5B expression in rat peri-ischemic brain area, especially at day 14 and 28 after MCAO (n = 4, P<0.05 or P<0.01). Immunofluorescence analysis showed that in the peri-ischemic area, netrin-1 was expressed in neuronal perikarya, DCC, however, was expressed in neural processes and peri-vascular astrocytes, while Unc5B was expressed mostly in neuronal perikarya and some processes. These results suggest that netrin-1 and its receptors DCC and Unc5B may engage in exercise-induced neural circuit remodeling in the peri-ischemic area, and exercise may promote survival of neurons in this area by regulating netrin-1-Unc5B signaling. Additionally, netrin-1 may also play a role in brain-blood barrier via DCC-immunoreactive peri-vascular astrocytes. In conclusion, we demonstrate that treadmill exercise has beneficial effects that may be attributed, at least in part, to the involvement of netrin-1 and its receptors DCC and Unc5B in the neuronal and vascular activities in brain-ischemic rats.

Discriminating two races of Liobagrus marginatoides by cytogenetic analysis

Although two kinds of Liobagrus marginatoides should belong to the same species according to the taxonomy of fish morphology, the results of cytogenetic analysis showed they are two different races.