Can the study of self-assembly in solution lead to a good model for the nucleation pathway? The case of tolfenamic acid

To further our understanding of the role of solution chemistry in directing nucleation processes new experimental and computational data are presented on the solution and crystallisation chemistry of tolfenamic acid (TA), a benchmark polymorphic compound.

To further our understanding of the role of solution chemistry in directing nucleation processes new experimental and computational data are presented on the solution and crystallisation chemistry of tolfenamic acid (TA), a benchmark polymorphic compound. With these, and previously published data, we were able to establish that TA is rapidly fluctuating between conformers in solution with either solvated monomers or dimers present depending on the solvent. Hence, despite the fact that conformational polymorphs can be obtained from crystallisations in ethanol, we found no links between solution chemistry and crystallisation outcomes. We discuss the implications of these conclusions for the nature of the nucleation pathway via dimers and clusters and raise experimental questions about how best to undertake relevant crystallisation studies.

[Activation of transcription factor NF-κB in a rat model of cardiac fibrosis induced by β-adrenoceptor stimulation]

OBJECTIVE

To establish a model of cardiac fibrosis induced by isoproterenol (ISO), the non-selective β adrenoceptor agonist, injected subcutaneously for 7 days in rats, and to observe changes of transcription factor NF-κB in the model.

METHODS

Male SD rats weighing 280-320 g were injected with ISO (0.25 mg/kg/d) subcutaneously for 7 days to induce cardiac fibrosis. The collagen volume fraction was determined by quantitative morphometry of picrosirius red stained left ventricular sections. Collagen types I/III and IL-6 mRNA expressions were analyzed by real time PCR. The pathological changes of the heart were investigated by Hematoxylin and Eosin staining. NF-κB was localized by immunohistochemistry (IHC) and phosphorylated NF-κB levels were assessed by Western blot analysis.

RESULTS

Compared with the controls, ISO significantly elevated the sirius red stained area and collagen volume fraction (12.01±1.644 vs. 0.95±0.067, P<0.001). Similarly, ISO increased the mRNA expressions of collagen Iand collagen III of the heart compared with the controls (10.51±0.47 vs. 0.98±0.02,P<0.001 for collagen I; 9.58±1.33 vs. 1.02±0.02, P<0.001 for collagen III). The number of nuclei was increased and nuclear accumulation was presented in myocardial tissue induced by ISO. The mRNA expression of IL-6 increased in ISO group (1.64±0.18 vs. 1.04±0.07, P<0.01). ISO induced NF-κB nuclear translocation, accompanied by an increase in phosphorylation of NF-κB (10.83±2.05 vs. 1.05±0.27, P<0.001).

CONCLUSION

We conclude that the model of cardiac fibrosis can be successfully induced by ISO injected subcutaneously for 7 days in rats and the activation of nuclear factor NF-κB increased by β-adrenoceptor stimulation.

Altered intrinsic regional activity and corresponding brain pathways reflect the symptom severity of functional dyspepsia

BACKGROUND

Increasing evidence shows central abnormalities in functional dyspepsia (FD) patients, but whether the symptom severity is directly reflected in altered brain patterns remains unclear. The purpose of this study was to explore how FD affected the resting functional brain patterns for different degrees of symptom severity.

METHODS

Functional magnetic resonance imaging was carried out in 40 FD patients and 20 healthy controls. The resting-state brain changes in regional homogeneity (ReHo) and seed correlation analysis were investigated in patients relative to controls. To what degree the brain changes reflected the severity of the disease was assessed by a pattern classification technique.

KEY RESULTS

Altered ReHo values (p < 0.05, FDR corrected) were discovered in multiple brain areas in FD patients, and only the anterior cingulate cortex (ACC) and thalamus exhibited significant correlation with the severity of dyspepsia symptoms. Compared with controls, the neural signal changes of the thalamus were not found in the less severe FD patient group but in the relatively more severe group, while the ACC showed aberrations in both groups. Seed-based correlation analysis revealed ACC- and thalamus-related functional connectivity differences between FD patients and controls at a voxel-wise level, and the altered thalamic circuits provided the best performance in distinguishing FD patients with different levels of symptom severity.

CONCLUSIONS & INFERENCES

Our results indicated that the functional abnormalities of the ACC and thalamus may occur at different clinical courses in FD. This may help us better understand the progression of FD.

Prognostic value of the International Society on Thrombosis and Haemostasis scoring system for overt disseminated intravascular coagulation in emergency department sepsis

PURPOSE

The International Society on Thrombosis and Haemostasis (ISTH) scoring system is a useful tool to diagnosis overt disseminated intravascular coagulation in clinical practice. The main purposes of this study were to investigate the prognostic value of the ISTH score in emergency department (ED) sepsis and compare the ISTH score with two established scoring systems, the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and two biomarkers,procalcitonin (PCT) and C-reactive protein (CRP).

METHODS

Septic patients were consecutively enrolled from the ED of Beijing Chaoyang Hospital, China. The ISTH score, SOFA score and APACHE II score were calculated, and PCT and CRP levels were measured on enrollment. A 30-day follow-up was performed.

RESULTS

A total of 680 septic patients were enrolled in this study. The Cox regression analysis showed that the ISTH score had a greater effect on 30-day mortality prediction, and the receiver operating characteristic curve analysis showed that the accuracy of the ISTH score in prediction of 30-day mortality was better than the SOFA score, the APACHE II score, PCT and CRP. Combination of the ISTH score and CRP can enhance the predictive accuracy of 30-day mortality.

CONCLUSION

The ISTH score is a valuable scoring system in the prognosis evaluation in ED sepsis.

Effect of stenting on patients with chronic internal carotid artery occlusion

AIM

Effects of carotid artery stenting (CAS) on patients with chronic internal carotid artery occlusion are unknown.

METHODS

This study included 21 patients who underwent successful CAS treatment and 41 patients who received optimal medical therapy. Modified Rankin Scale (mRS) and cardiocerebral vascular events were compared between CAS and medical therapy group.

RESULTS

The mRS in CAS group was lower than in control group during a 2-year follow up (P<0.05 or 0.01). The combined cerebrovascular events and mortality in study group was lower than in the control group (33.4% vs. 56.1%, P=0.045), but there was no statistically significant difference in the cerebrovascular event (28.6% vs. 46.3%, P=0.088) or mortality rate (4.8% vs. 9.8%, P=0.247) between the two groups. Cox regression analysis revealed that smoking (RR=3.189, 95% CI 1.020-9.968, P=0.046), diabetes (RR=2.717, 95% CI 1.113-6.631, P=0.028), and baseline National Institute of Health stroke scale (RR=2.984, 95% CI 1.049-8.485, P=0.040) were independent risk factors for major cerebrovascular events following CAS.

CONCLUSION

CAS was superior to drug therapy in achieving better functional outcomes in patients with chronic internal carotid artery occlusion. However, CAS was not associated with a statistically significant reduction in cerebrovascular events or mortality. Larger and randomized clinical trials are required to ascertain the long-term benefits of CAS in patients with chronic internal carotid artery occlusion.

Feasibility and safety of stenting for symptomatic carotid arterial dissection

OBJECTIVE

To determine the procedural feasibility and safety of carotid angioplasty and stent placement of carotid artery dissection (CAD) patients who had failed antithrombotic therapy in acute dissection.

METHODS

A series of 33 consecutive patients (mean age, 40.21 years; 29 men and 4 women) who underwent angioplasty and stent placement for symptomatic carotid artery dissection (sCAD) from May 2005 to December 2010 in the Nanjing Stroke Registry Program (NSRP) was retrospectively reviewed. All the included patients had been diagnosed definitively based on catheter angiography, and had failed to respond to medical therapy during the course of initial hospital admission. The baseline and followed up data of these patients were collected and analyzed.

RESULTS

Of all the 33 included patients, 32 patients had achieved technical success without any intraoperative complications. Two patients manifested ipsilateral Horner sign on the next day after stenting, and one of them suffered from recurrence of transient ischaemic attack (TIA) during the course of follow up, but completely remission via antithrombotic therapy.

CONCLUSION

Endovascular stenting is a feasible and safe therapeutic strategy of CAD patients who have failed medical therapy.

Streptozotocin-induced diabetic rat-derived bone marrow mesenchymal stem cells have impaired abilities in proliferation, paracrine, antiapoptosis, and myogenic differentiation

BACKGROUND

Diabetes has been widely recognized as a major risk factor for cardiovascular disease. With the development of the regenerative medicine, autologous bone marrow-derived mesenchymal stem cells (BMSCs), transplantation can effectively improve cardiac function after myocardial infarction. However, the BMSCs used in most previous studies are derived from young or normal donors. Little is know about the biological characters change of BMSCs in diabetes mellitus.

METHODS

BMSCs were taken from the streptozotocin (STZ)-induced diabetic rats and normal control rats. Cell proliferation was evaluated by CCK-8 assay. Production of vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF)-1 were measured by enzyme-linked immunosorbent assay. Apoptosis under hypoxia and serum deprivation culture conditions were detected by Hoechst 33342 stain and flow cytometry. Myogenic differentiation, induced by 5-azacytidine was assessed by using immunocytochemical staining for the expression of sarcomeric α-actin and desmin.

RESULTS

Diabetic rat models were successfully induced by intraperitoneal injection of STZ. The proliferative abilities of BMSCs derived from diabetic rats decreased significantly compared with that from normal rats (P < .05). Similar results were also presented in the cytokines (VEGF and IGF-1) release (P = .02 and P < .01, respectively) that the ability of antiapoptosis and myogenic differentiation decreased obviously between diabetes group and the normal control group (P < .01).

CONCLUSION

BMSCs from STZ-induced diabetic rats could be successfully harvested and expanded in vitro culture condition; their morphology was very similar to normal control group, with minor changes. However, the proliferative and differentiation properties of diabetic BMSCs, as well as cytokine release and antiapoptosis ability, were significantly impaired.