抗高血压药物与罹患癌症的风险:324168例参与随机临床试验病人的荟萃分析和试验序贯分析

长期以来,一直存在抗高血压药物是否有致癌作用的争议.自从在年龄>50岁的妇女中使用萝芙碱提取物造成乳腺癌发病率增加的报道后[1],这一争议已持续了30年.Sipahi和同事们最近的研究显示:血管紧张素受体拮抗剂(angiotensin receptor-blockers,ARB)有较高的致癌风险.这一发现再次引发了抗...     

Surface study of collagen/poloxamine hydrogels by a 'deep freezing' ToF-SIMS approach

In order to determine the presence of collagen molecules at the surface of a collagen-modified poloxamine hydrogel (a semi-interpenetrating network), the surface composition was studied using Time-of-Flight Secondary Ion Mass Spectra (ToF-SIMS). Collagen was added to the poloxamine hydrogel (poloxamine is a commercially available four-arm poly(ethylene oxide)/poly(propylene oxide) block copolymer, PEO/PPO) to promote the attachment of endothelial or liver cells. X-ray photoelectron spectroscopy (XPS) of dry samples showed a sharp increase in the N content from 0.6% in a pure poloxamine hydrogel to 8.8% in the collagen-containing material. Afterwards, the surface was studied by a 'deep freezing' ToF-SIMS approach under progressive heating from -120 to -60 degrees C. The positive spectrum of collagen/poloxamine at -65 degrees C displayed distinct signals corresponding to different amino acid fragments such as CH4N+ (30 m/z, Gly), C3HN2+ (43 m/z, Arg), C2H6N+ (44 m/z, Ala) and C4H5N2+(81m/z, His) and others corresponding to the PEO and PPO blocks of poloxamine. In addition, the negative spectrum showed peaks at 26 m/z (CN-), 32 m/z (S-) and 42 m/z (CNO-) characteristic of fragments of the collagen molecule. Imaging experiments indicated the homogeneous distribution of the collagen on the surface. These results supported the use of ToF-SIMS for the surface characterization of hydrated hydrogels and confirmed the collagen presence as the means whereby cells attach to the modified poloxamine matrix.     

Novel insight into the detailed myocardial motion and deformation of the rodent heart using high-resolution phase contrast cardiovascular magnetic resonance

Background

Phase contrast velocimetry cardiovascular magnetic resonance (PC-CMR) is a powerful and versatile tool allowing assessment of in vivo motion of the myocardium. However, PC-CMR is sensitive to motion related artifacts causing errors that are geometrically systematic, rendering regional analysis of myocardial function challenging. The objective of this study was to establish an optimized PC-CMR method able to provide novel insight in the complex regional motion and strain of the rodent myocardium, and provide a proof-of-concept in normal and diseased rat hearts with higher temporal and spatial resolution than previously reported.

Methods

A PC-CMR protocol optimized for assessing the motion and deformation of the myocardium in rats with high spatiotemporal resolution was established, and ten animals with different degree of cardiac dysfunction underwent examination and served as proof-of-concept. Global and regional myocardial velocities and circumferential strain were calculated, and the results were compared to five control animals. Furthermore, the global strain measurements were validated against speckle-tracking echocardiography, and inter- and intrastudy variability of the protocol were evaluated.

Results

The presented method allows assessment of regional myocardial function in rats with high level of detail; temporal resolution was 3.2 ms, and analysis was done using 32 circumferential segments. In the dysfunctional hearts, global and regional function were distinctly altered, including reduced global peak values, increased regional heterogeneity and increased index of dyssynchrony. Strain derived from the PC-CMR data was in excellent agreement with echocardiography (r = 0.95, p < 0.001; limits-of-agreement −0.02 ± 3.92%strain), and intra- and interstudy variability were low for both velocity and strain (limits-of-agreement, radial motion: 0.01 ± 0.32 cm/s and −0.06 ± 0.75 cm/s; circumferential strain: -0.16 ± 0.89%strain and −0.71 ± 1.67%strain, for intra- and interstudy, respectively).

Conclusion

We demonstrate, for the first time, that PC-CMR enables high-resolution evaluation of in vivo circumferential strain in addition to myocardial motion of the rat heart. In combination with the superior geometric robustness of CMR, this ultimately provides a tool for longitudinal studies of regional function in rodents with high level of detail.     

Incidence of colorectal cancer in Kashmir valley, India

Background

There is wide variation in the incidence of colorectal cancer globally and also within the same country among different racial or ethnic groups. The present population-based study was undertaken to determine the incidence of colorectal cancer in Kashmiri population which is non-migratory and ethnically homogeneous having stable food habits.

Methods

Over a period of one year, all newly diagnosed and histological proved cases of colorectal cancer in all possible areas, where such patients are diagnosed and treated were prospectively registered.

Results

A total of 212 cases of colorectal cancers were registered; of them 113 (53.3%) originated in the colon and other 99 (46.7%) in rectum. Male to female ratio was 1.2:1. The crude incidence rate of colorectal cancer was 3.65/100,000; it was 3.78 in males, and 3.50/100,000 in females. The incidence rates for colorectal cancer in Muslims and Hindus were different. The crude incidence rate for colorectal carcinoma was highest for district Srinagar 6.19/100,000 (urban area) and lowest for district Kupwara (rural area) 1.59/100,000. The highest numbers of cases were detected in the age group 55–59 years (n?=?34). The age-specific rate for colorectal carcinoma was highest in the age group 55–59 years (17.21/100,000), followed by 65–69 years (14.86/100,000). The age standardized incidence rate was 4.52/100,000 per year. The truncated age adjusted incidence rates in age group 35–64 years was 8.31/100,000; while that for colorectal carcinoma was 8.77/100,000 in males and 7.66/100,000 in females.

Conclusion

We conclude that the incidence of colorectal cancer in Kashmir valley is similar to that reported in the rest of India.     

New insights into necrotizing enterocolitis: From laboratory observation to personalized prevention and treatment

Background/purpose

Necrotizing enterocolitis (NEC) is a devastating disease of prematurity that develops after feeding, often without warning, and results in diffuse intestinal necrosis leading to sepsis and death in many cases. The lack of improvement in overall survival is influenced by nonspecific diagnostic modalities as well as inexact and nonpersonalized treatment strategies.